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Sample records for ironiii pvc membrane

  1. Urea biosensors based on PVC membrane containing palmitic acid.

    PubMed

    Karakuş, Emine; Pekyardimci, Sule; Esma, Kiliç

    2005-01-01

    A new urea biosensor was prepared by immobilizing urease with four different procedures on poly(vinylchloride) (PVC) ammonium membrane electrode containing palmitic acid by using nonactine as an ammonium-ionophore. The analytical characteristics were investigated and were compared those of the biosensor prepared by using carboxylated PVC. The effect of pH, buffer concentration, temperature, urease concentration, stirring rate and enzyme immobilization procedures on the response to urea of the enzyme electrode were investigated. The linear working range and sensitivity of the biosensor were also determined. The urea biosensor prepared by using the PVC membranes containing palmitic acid showed more effective performance than those of the carboxylated PVC based biosensors. Additionally, urea assay in serum was successfully carried out by using the standard addition method.

  2. Reduction of thrombogenicity of PVC-based sodium selective membrane electrodes using heparin-modified chitosan.

    PubMed

    Badr, Ibrahim H A; Gouda, M; Abdel-Sattar, R; Sayour, Hossam E M

    2014-01-01

    Heparin-modified chitosan (H-chitosan) membrane was utilized to enhance biocompatibility of sodium selective membrane electrode based on the highly thrombogenic polyvinyl chloride (PVC). Sodium ion sensing film was prepared using PVC, sodium ionophore-X, potassium tetrakis(chlorophenyl)-borate, and o-nitrophenyloctylether. The PVC-based sensing film was sandwiched to chitosan or H-chitosan to prevent platelet adhesion on the surface of PVC. Potentiometric response characteristics of PVC-chitosan and PVC-H-chitosan membrane electrodes were found to be comparable to that of a control PVC based sodium-selective electrode. This indicates that chitosan and H-chitosan layers do not alter the response behaviour of the PVC-based sensing film. Biocompatibility of H-chitosan was confirmed by in vitro platelet adhesion study. The platelet adhesion investigations indicated that H-chitosan film is less thrombogenic compared to PVC, which could result in enhancement of biocompatibility of sodium selective membrane electrodes based on PVC, while maintaining the overall electrochemical performance of the PVC-based sensing film.

  3. Reverse osmosis membrane composition, structure and performance modification by bisulphite, iron(III), bromide and chlorite exposure.

    PubMed

    Ferrer, O; Gibert, O; Cortina, J L

    2016-10-15

    Reverse osmosis (RO) membrane exposure to bisulphite, chlorite, bromide and iron(III) was assessed in terms of membrane composition, structure and performance. Membrane composition was determined by Rutherford backscattering spectrometry (RBS) and membrane performance was assessed by water and chloride permeation, using a modified version of the solution-diffusion model. Iron(III) dosage in presence of bisulphite led to an autooxidation of the latter, probably generating free radicals which damaged the membrane. It comprised a significant raise in chloride passage (chloride permeation coefficient increased 5.3-5.1 fold compared to the virgin membrane under the conditions studied) rapidly. No major differences in terms of water permeability and membrane composition were observed. Nevertheless, an increase in the size of the network pores, and a raise in the fraction of aggregate pores of the polyamide (PA) layer were identified, but no amide bond cleavage was observed. These structural changes were therefore, in accordance with the transport properties observed.

  4. Celluloses filled ENR/PVC membranes for palm oil mill effluent (POME) treatment

    NASA Astrophysics Data System (ADS)

    Shamsuddin, Mohd Razali; Abdullah, Ibrahim; Othaman, Rizafizah

    2013-11-01

    Membranes from composite materials have been used especially in water treatment applications. In this paper the composite membranes of celluloses filled ENR/PVC were successfully prepared for POME treatment application. The preparation of the membrane involves solution blending, casting, phase inversion and drying methods. Two types of fillers, cellulose (Cell) and cellulose grafting polymethyl methacrylate (Cell-g-PMMA) were added into ENR/PVC matrix in various compositions (1, 5, 10, 15 and 20 wt%) to determine the effect of the filler to the performance of the membrane. The membranes were characterized by using FTIR and SEM. Membrane properties in terms of porosity and water flux were examined using mathematical calculation. FTIR spectrum shows the existence of stretching vibration from the functional group of ester carbonyl, -C=O at peak 1725 cm-1 that belongs to Cell-g-PMMA filler in ENR/PVC/Cell-g-PMMA membrane which makes the membranes slightly hydrophobic. SEM micrographs exhibit that pores were formed on both ENR/PVC/Cell and ENR/PVC/Cell-g-PMMA membranes. Water flux test indicates that ENR/PVC/Cell-20% was the highest because the addition of Cell increases the hydrophilicity of the membrane. In POME treatment, ENR/PVC/Cell-20% and ENR/PVC/Cell-g-PMMA-10% showed the highest decolorization.

  5. Gas permeability of ENR/PVC membrane with the addition of inorganic fillers

    NASA Astrophysics Data System (ADS)

    Nor, Farhan Mohd; Abdullah, Ibrahim; Othaman, Rizafizah

    2013-11-01

    Epoxidized natural rubber (ENR) was blended with polyvinyl chloride to form a flexible and porous membrane. SiO2 and MgO were added into the membrane for pore formation and the effects of the addition was investigated by means of FTIR, TGA, SEM, EDX and gas permeability towards CO2 and N2 gases. FTIR result showed the presence of Si-O-Si asymmetric stretching at the absorption peak of 467 cm-1 for ENR/PVC/SiO2 membrane and MgO signature peak at 3700 cm-1 for ENR/PVC/MgO membrane. Thermal analysis showed that the thermal stability of ENR/PVC membrane increased with the addition of fillers. Morphological studies prove that subsequently, the pores in the membranes increased showing that some of the added fillers were drawn towards the water leaving empty spaces and tracks. The remaining fillers are homogenously distributed on the surface of the membranes. CO2 and N2 gas permeability increased with increasing filler content and the permeability of ENR/PVC/SiO2 membranes towards CO2 and N2 gasses was higher than ENR/PVC/MgO membranes.

  6. PVC membrane based potentiometric sensors for uranium determination.

    PubMed

    Hassan, S S; Ali, M M; Attawiya, A M

    2001-07-06

    Two novel uranyl PVC matrix membrane sensors responsive to uranyl ion are described. The first sensor incorporates tris(2-ethylhexyl)phosphate (TEHP) as both electroactive material and plasticizer and sodium tetraphenylborate (NaTPB) as an ion discriminator. The sensor displays a rapid and linear response for UO(2)(2+) ions over the concentration range 1x10(-1)-2x10(-5) mol l(-1) UO(2)(2+) with a cationic slope of 25.0+/-0.2 mV decade(-1). The working pH range is 2.8-3.6 and the life span is 4 weeks. The second sensor contains O-(1,2-dihydro-2-oxo-1-pyridyl)-N,N,N',N'-bis(tetra-methylene)uronium hexafluorophosphate (TPTU) as a sensing material, sodium tetraphenylborate as an ion discriminator and dioctyl phenylphosphonate (DOPP) as a plasticizer. Linear and stable response for 1x10(-1)-5x10(-5) mol l(-1) UO(2)(2+) with near-Nernstian slope of 27.5+/-0.2 mV decade(-1) are obtained. The working pH range is 2.5-3.5 and the life span of the sensor is 6 weeks. Interference from many inorganic cations is negligible for both sensors. However, interference caused by some ions (e.g. Th(4+), Cu(2+), Fe(3+)) is eliminated by a prior ion exchange or solvent extraction step. Direct potentiometric determination of as little as 5 mug ml(-1) uranium in aqueous solutions shows an average recovery of 97.2+/-1.3%. Application for the determination of uranium at levels of 0.01-1 wt.% in naturally occurring and certified ores gives results with good correlation with data obtained by X-ray fluorescence.

  7. PVC Membrane Sensors for Potentiometric Determination of Acebutolol

    PubMed Central

    Mostafa, Gamal Abdel-Hafiz; Hefnawy, Mohamed Mahmoud; Al-Majed, Abdulrahman

    2007-01-01

    The construction and general performance characteristics of two novel potentiometric membrane sensors responsive to the acebutolol are described. The sensors are based on the use of ion-association complexes of acebutolol (AC) with tetraphenylborate(TPB) (I) and phosphomolybdate(PM) (II) as exchange sites in a PVC matrix. The sensors show a fast, stable and near- Nernstian for the mono charge cation of AC over the concentration range 1×10-3 - ∼10-6 M at 25 °C over the pH range 2.0 - 6.0 with cationic slope of 51.5 ± 0.5 and 53.0 ± 0.5 per concentration decade for AC-I and AC-II sensors respectively. The lower detection limit is 6×10-6 M and 4×0-6 M with the response time 20-30 s in the same order of both sensors. Selectivity coefficients of AC related to a number of interfering cation and some organic compounds were investigated. There are negligible interferences are caused by most of the investigated species. The direct determination of 3 - 370 μg/ml of AC shows an average recovery of 99.4 and 99.5% and a mean relative standard deviation of 1.5% at 100.0 μg/ml for sensor I and II respectively. The results obtained by determination of AC in tablets using the proposed sensors which comparable favorably with those obtained by the British pharmacopoeia method. In the present investigation the electrodes have been utilized as end point indicator for some precipitation titration reactions.

  8. Effect of radiation on properties of ENR/PVC/SiO{sub 2} membrane

    SciTech Connect

    Ismail, Nur Farahein Hadina; Abdullah, Ibrahim; Daik, Rusli; Ahmad, Ishak; Jamil, Suzereen; Lazim, Mohammad Azwan Mat; Othaman, Rizafizah

    2015-09-25

    In this study epoxidised natural rubber (ENR)/polyvinyl chloride (PVC) matrix was prepared by melt blending. The matrix was swelled in THF and silica as a filler was introduced to the solution to generate pore formation. The ENR/PVC/10 % SiO{sub 2} membrane was prepared using a casting knife technique. The membrane was irradiated using 2 MeV electron beam accelerator at a dose range of 10-100 kGy. The effect of electron beam irradiation of the membrane was studied by undergo characterization of Scanning electron microscope (SEM) and Fourier transform infra red (FTIR). Morphological studies showed that pores generated in ENR/PVC/10 % SiO{sub 2} membrane increased with the dosage of radiation. While FTIR analysis showed the presence of peak of Si-O-Si asymmetric stretching at 834 cm{sup −1}. There are no significant changes in the functional group before and after radiation.

  9. Effect of radiation on properties of ENR/PVC/SiO2 membrane

    NASA Astrophysics Data System (ADS)

    Ismail, Nur Farahein Hadina; Abdullah, Ibrahim; Daik, Rusli; Ahmad, Ishak; Jamil, Suzereen; Lazim, Mohammad Azwan Mat; Othaman, Rizafizah

    2015-09-01

    In this study epoxidised natural rubber (ENR)/polyvinyl chloride (PVC) matrix was prepared by melt blending. The matrix was swelled in THF and silica as a filler was introduced to the solution to generate pore formation. The ENR/PVC/10 % SiO2 membrane was prepared using a casting knife technique. The membrane was irradiated using 2 MeV electron beam accelerator at a dose range of 10-100 kGy. The effect of electron beam irradiation of the membrane was studied by undergo characterization of Scanning electron microscope (SEM) and Fourier transform infra red (FTIR). Morphological studies showed that pores generated in ENR/PVC/10 % SiO2 membrane increased with the dosage of radiation. While FTIR analysis showed the presence of peak of Si-O-Si asymmetric stretching at 834 cm-1. There are no significant changes in the functional group before and after radiation.

  10. Polymeric plasticizer extends the lifetime of PVC-membrane ion-selective electrodes.

    PubMed

    Zahran, Elsayed M; New, Andrea; Gavalas, Vasilis; Bachas, Leonidas G

    2014-02-21

    The nature of the plasticizer plays a pivotal role in the analytical performance of polymer membrane ion sensors. Conventional plasticizers suffer leaching or migration from the membrane and exudation, both of which could limit the lifetime of sensors based on plasticized membranes. Herein, we describe the use of polyester sebacate (PES), a model polymeric plasticizer, in the preparation of poly (vinyl chloride) (PVC) membrane ion-selective electrodes (ISEs) using valinomycin as ionophore. PVC membrane electrodes plasticized with polyester sebacate demonstrated potentiometric response characteristics that compared favorably to ones plasticized with the conventional and similarly structured plasticizer bis(2-ethylhexyl) sebacate (DOS). Increasing the content of polyester sebacate in the membrane enhanced the response and improved the selectivity of valinomycin-based ISEs toward potassium over sodium. Various methods, including electrochemical impedance spectroscopy, UV-vis spectroscopy, dark field optical microscopy, and potentiometry were employed to study the effect of plasticizer on the leaching of the membrane components and the lifetime of both DOS- and PES-plasticized membranes. PES-plasticized electrodes maintained Nernstian response and high selectivity for more than four months, an improvement over DOS-plasticized membrane electrodes. This was attributed to enhanced retention of the membrane components because of the high polymeric nature of the polyester sebacate. These characteristics suggest that polyester sebacate is a good candidate to replace the conventional plasticizers in preparing PVC membrane electrodes with longer lifetime.

  11. Functionalization of PVC membrane with ss oligonucleotides for a potentiometric biosensor.

    PubMed

    Shishkanova, T V; Volf, R; Krondak, M; Král, V

    2007-05-15

    A novel application of a single stranded (ss) oligonucleotide as an active component of polymeric membrane in an ion-selective electrode (ISE) is described. The original oligonucleotides, oligo(dA)(15), modified by cholesterol, triphenylmethyl and hexadecyl derivatives, were immobilized into poly(vinyl chloride) (PVC) membrane using extraction protocol. In parallel, the adsorption protocol was used to immobilize unmodified oligo(dA)(15) on the PVC membrane based on tridodecylmethyammonium chloride (TDDMA(+)Cl(-)). Immobilization of ss oligonucleotide probe through spacer was more effective for the potentiometric detection of the hybridization between complementary oligonucleotides. It was found that cholesterol-oligo(dA)(15) modified membranes were sensitive toward complementary oligo(dT)(15) in the concentration range 2-80 nM at pH 7. An explanation for the detection mechanism is proposed.

  12. Comparative Study of PVC-Free All-Solid-State, PVC Membrane, and Carbon Paste Ion-Selective Electrodes for the Determination of Dapoxetine Hydrochloride in Pharmaceutical Formulation.

    PubMed

    Aziz, Azza; Khamees, Nesrin; Mohamed, Tagreed Abdel-Fattah; Derar, Abeer Rashad

    2016-11-01

    The potentiometric response characteristics and analytical applications of a poly(vinyl chloride) (PVC)-free all-solid-state ion-selective electrode for dapoxetine hydrochloride (DAP) are examined. The Nernstian response of the electrode was evaluated by comparison with PVC-based liquid membrane and carbon paste electrodes. The PVC-free electrode is prepared by direct incorporation of dapoxetine-tetraphenyl borate (DAP-TPB) as a sensing element into a commercial nail varnish containing cellulose acetate propionate. The composite was applied onto a 3 mm diameter graphite disk electrode. The electrode exhibited a Nernstian slope of 56.0 mV/decade in the concentration range of 1 × 10-4 to 1 × 10-2 mol/L with an LOD of 2 × 10-5 mol/L. The electrode is independent of pH in the range of 2 to 6 and showed good selectivity for DAP with respect to a large number of inorganic cations and amino acids. Comparable Nernstian slope, sensitivity, pH range, and selectivity pattern were obtained with a PVC membrane and a carbon paste incorporating DAP-TPB as a sensing element and dioctylphthalate as a solvent mediator. The electrodes were used for the determination of DAP in pure solution and in tablets without extraction with high accuracy and precision (RSD ≤ 2%). The nail varnish solid-state electrode is simple, economical, and rapid when compared with PVC membrane and carbon paste electrodes.

  13. Plasticizer Effects in the PVC Membrane of the Dibasic Phosphate Selective Electrode.

    PubMed

    Carey, Clifton

    2015-12-01

    The PVC membrane of an ion-selective electrode (ISE) sensitive to dibasic phosphate ions (HPO4-ISE) has not been optimized for maximum selectivity, sensitivity, and useable ISE lifetime and further work was necessary to improve its performance. Two areas of investigation are reported here: include the parameters for the lipophilicity of the plasticizer compound used and the amount of cyclic polyamine ionophore incorporated in the PVC membrane. Six candidate plasticizers with a range of lipophilicity were evaluated for their effect on the useable lifetime, sensitivity, and selectivity of the ISE against 13 different anions. Selectivity was determined by a modified fixed interferent method, sensitivity was determined without interferents, and the usable lifetime evaluated at the elapsed time where 50% of the HPO4-ISE failed (L50). The results show that choosing a plasticizer that has a lipophilicity similar to the ionophore's results in the best selectivity and sensitivity and the longest L50.

  14. Plasticizer Effects in the PVC Membrane of the Dibasic Phosphate Selective Electrode

    PubMed Central

    Carey, Clifton

    2016-01-01

    The PVC membrane of an ion-selective electrode (ISE) sensitive to dibasic phosphate ions (HPO4-ISE) has not been optimized for maximum selectivity, sensitivity, and useable ISE lifetime and further work was necessary to improve its performance. Two areas of investigation are reported here: include the parameters for the lipophilicity of the plasticizer compound used and the amount of cyclic polyamine ionophore incorporated in the PVC membrane. Six candidate plasticizers with a range of lipophilicity were evaluated for their effect on the useable lifetime, sensitivity, and selectivity of the ISE against 13 different anions. Selectivity was determined by a modified fixed interferent method, sensitivity was determined without interferents, and the usable lifetime evaluated at the elapsed time where 50% of the HPO4-ISE failed (L50). The results show that choosing a plasticizer that has a lipophilicity similar to the ionophore's results in the best selectivity and sensitivity and the longest L50. PMID:27347487

  15. Potentiometric Cr(VI) selective electrode based on novel ionophore-immobilized PVC membranes.

    PubMed

    Choi, Young-Woo; Minoura, Norihiko; Moon, Seung-Hyeon

    2005-06-15

    For the determination of Cr(VI) concentrations with a potentiometric ion-selective electrode (ISE), ionophore-immobilized membranes were prepared by ultraviolet (UV)-induced graft polymerization followed by chemical treatment. Novel ionophores comprising various amine structures were immobilized onto poly(vinyl chloride) (PVC) matrixes, and these were examined to determine Cr(VI) selectively. Of the three ionophores examined in this study, the membranes with N,N,N,N-tetrakis(3-aminopropyl)-1,4-butanediamine (DABAm4) exhibited the highest Cr(VI) ion selectivity in both extraction and potentiometry experiments. The plasticizer in the membrane was optimized as 1.0ml o-nitrophenyl octyl ether (NPOE)/g PVC to form diffusible channels. The potentiometric studies revealed that the performance of DABAm4-immobilized PVC was equivalent to that of mobile ionophores in supported liquid membranes (SLMs). A reproducible response of Cr(VI) was attained within a response time of 1s in the range of 2.16x10(-6) to 0.1M, using the membrane prepared in this study. The selectivity for the Cr(VI) ion against the other interfering ions was compared reasonably between a solvent extraction and potentiometry. The long-term response of the Cr(VI) ISE showed slight deterioration over a continuous operation for 6 months, while the detection limit slightly decreased due to the leaching-out of the plasticizer. The ISE along with the DABAm4 immobilized membrane showed a higher Cr(VI) ion selectivity and more stable response under long-term usage than ISEs with typical SLMs.

  16. Portable e-Tongue based on Multi-channel LAPS Array with PVC Membrane for Rapid Environment Detection

    NASA Astrophysics Data System (ADS)

    Ha, D.; Yu, H.; Hu, N.; Wu, C. X.; Zhou, J.; Kirsanov, Dmitry; Legin, Andrey; Wang, P.

    2011-09-01

    A new kind of portable e-Tongue based on multi-channel LAPS array with PVC membrane has been designed for the rapid detection of environment situation, especially the seawater. It has the great advantages of depositing membranes which are offered by Chemistry Department, Saint-Petersburg State University on the sensors artificially with convenience and efficiency. To detect various heavy metal ions (Pb2+, Cd2+, Zn2+) simultaneously, respective Polyvinyl Chloride (PVC) membrane could be prepared on the surface of the silicon-based sensor in different channel.

  17. [Study on the coated carbon PVC membrane selective electrode of aconitine].

    PubMed

    Lü, T; Si, X; Chen, B; Yin, G

    1990-09-01

    Coated carbon PVC membrane selective electrode of aconitine was prepared with the Aconitine-tetraphenylborate ion-associate complex as the electroactive material. The electrode showed a linear response to aconitine within the concentration range 1.0 x 10(-2) - 5.0 x 10(-5) mol/L. The limit of detection was 6.3 x 10(-6) mol/L and the slope of the electrode was 57.6 mV/decade. The authors established a basis and a method for the control of content limit of aconitine in Shen Fu Injection with this electrode.

  18. PVC membrane sensor for diclofenac: applications in pharmaceutical analysis and drug binding studies.

    PubMed

    Maleki, R; Matin, A A; Hosseinzadeh, R; Jouyban, A

    2007-09-01

    A PVC membrane sensor for diclofenac based on its ion pair complex with silver is prepared. The influences of membrane composition (PVC, plasticizer, and ion pair complex), pH of test solution and presence of other anions on the performance of the electrode were investigated. The optimized membrane demonstrates Nernstian response (-58.9 +/- 0.2 mV/decade) for diclofenac anions over a wide linear range from 5.2 x 10(-5) to 1.1 x 10(-2) M at 25 +/- 1 degree C. The potentiometric response is independent from pH at the range of 6.0-9.5. The advantages of the proposed sensor are: easy preparation, good selectivity and fast response time. It was successfully used for determination of diclofenac in pharmaceuticals and also in potentiometric study of interaction of diclofenac with bovine serum albumin. The results of diclofenac assay with the proposed sensor were in good agreement with the official HPLC method.

  19. An oxalate selective electrode based on modified PVC-membrane with tetra-butylammonium--Clinoptilolite nanoparticles.

    PubMed

    Hoseini, Zohre; Nezamzadeh-Ejhieh, Alireza

    2016-03-01

    A modified PVC-membrane electrode with tetra-butylammonium bromide - Clinoptilolite nano-particles (TBA-NCP) showed good Nernstian slope (29.9±0.6 mV per decade of oxalate concentration) in concentration range of 3.1×10(-7)-8.3×10(-1) mol L(-1) with a detection limit of 1.5×10(-7) mol L(-1). The best performance was obtained with a membrane composition of 31.5% PVC, 62.5% DOP and 6% TBA-NCP in the temperature range of 20-35 °C and the pH range of 4-9. The fast response time and good reproducibility over a period of 3 months are other characteristics of the sensor. The proposed electrode was successfully used as an indicator electrode in titration of oxalate ions with CaCl2 solution. The proposed electrode was also used in direct potentiometric determination of oxalate in many real samples such as: mushroom, black and green tea, spinach and beet.

  20. Ionophore-based potentiometric PVC membrane sensors for determination of phenobarbitone in pharmaceutical formulations.

    PubMed

    Alrabiah, Haitham; Al-Majed, Abdulrahman; Abounassif, Mohammed; Mostafa, Gamal A E

    2016-12-01

    The fabrication and development of two polyvinyl chloride (PVC) membrane sensors for assaying phenobarbitone sodium are described. Sensors 1 and 2 were fabricated utilizing β- or γ-cyclodextrin as ionophore in the presence of tridodecylmethylammonium chloride as a membrane additive, and PVC and dioctyl phthalate as plasticizer. The analytical parameters of both sensors were evaluated according to the IUPAC guidelines. The proposed sensors showed rapid, stable anionic response (-59.1 and -62.0 mV per decade) over a relatively wide phenobarbitone concentration range (5.0 × 10-6-1 × 10-2 and 8 × 10-6-1 × 10-2 mol L-1) in the pH range of 9-11. The limit of detection was 3.5 × 10-6 and 7.0 × 10-6 mol L-1 for sensors 1 and 2, respectively. The fabricated sensors showed high selectivity for phenobarbitone over the investigated foreign species. An average recovery of 2.54 μg mL-1 phenobarbitone sodium was 97.4 and 101.1 %, while the mean relative standard deviation was 3.0 and 2.1 %, for sensors 1 and 2, respectively. The results acquired for determination of phenobarbitone in its dosage forms utilizing the proposed sensors are in good agreement with those obtained by the British Pharmacopoeial method.

  1. [Membrane fouling mechanism and control strategy for the pilot-scale submerged PVC-UF membrane process].

    PubMed

    Fan, Qing-ru; Xiao, Ping; Xiao, Feng; Qiao, Chun-guang; Qin, Tong; Wang, Dong-sheng

    2011-05-01

    In this paper, Lujing water supply plant in Jiangsu was selected to carry out the investigation in order to understand the constitutes of the membrane fouling, comment on the membrane cleaning methods and obtain the proper cleaning sequences. In the experiments, water quality of the raw water was measured; membrane characteristics of the plant and membrane cleaning methods were thoroughly analyzed. The results indicated that the hydrophobic acids (HOA) and hydrophilic matters (HIM) are the major components in the raw water, 40.34% and 28.48% respectively in mass fraction. EEM's results also demonstrated that aromatic protein II are the main constitutes in the DOMs. In addition, the turbidity can reach around 0.1 NTU and the DOM can be removed partially by the PVC-UF membrane process during the water production. The constitutes of those emulations demonstrated that inorganic ions and NOM were both contributed to the membrane fouling. Ca and Si were the major inorganic contributors; aromatic protein II, SMP and fulvic acid were the major organic ones. According to SEM observation the sequence of the membrane cleaning should be HCl first, then NaOH.

  2. Consecutive chemical cleaning of fouled PVC membrane using NaOH and ethanol during ultrafiltration of river water.

    PubMed

    Tian, Jia-yu; Chen, Zhong-lin; Yang, Yan-ling; Liang, Heng; Nan, Jun; Li, Gui-bai

    2010-01-01

    Chemical cleaning of fouled hollow-fiber polyvinyl chloride (PVC) membrane with the consecutive use of NaOH and ethanol during ultrafiltration of river water was investigated in the study. Results showed that through the chemical cleaning with 1% NaOH for 30min, a negative cleaning efficiency of -14.6% was observed for the PVC membrane. This might be due to the increase of membrane hydrophobicity, which was reflected by the increase of contact angle from 69.7 degrees to 87.6 degrees . On the other hand, the cleaning efficiency of 85.1% was obtained by the consecutive cleaning with 30min of 1% NaOH and 30min of ethanol. Individual ethanol cleaning could remove 48.5% of the irreversible resistance, indicating that NaOH cleaning also made its contribution (36.6%) to the removal of membrane foulants. Scanning electronic microscopy (SEM) and atomic force microscopy (AFM) analyses demonstrated that both NaOH and ethanol were not only able to eliminate the foulants on membrane surface, but also able to remove the in-pore fouling of the PVC membrane. The synergetic effects for removing membrane foulants were observed between the NaOH and ethanol. Furthermore, ethanol could also restore the hydrophilicity of the membrane by decreasing the contact angle from 87.6 degrees to 71.4 degrees . Considering that ethanol is easy to be used and reclaimed, the consecutive chemical cleaning by alkali and ethanol is recommended for PVC membrane in filtration of surface water.

  3. Potentiometric determination of ketotifen fumarate in pharmaceutical preparations and urine using carbon paste and PVC membrane selective electrodes.

    PubMed

    Frag, Eman Y Z; Mohamed, Gehad G; Khalil, Mohamed M; Hwehy, Mohammad M A

    2011-01-01

    This study compares between unmodified carbon paste (CPE; the paste has no ion pair) and polyvinyl chloride (PVC) membrane selective electrodes that were used in potentiometric determination of ketotifen fumarate (KTF), where sodium tetraphenylborate (NaTPB) was used as titrant. The performance characteristics of these sensors were evaluated according to IUPAC recommendations which reveal a fast, stable, and linear response for KTF over the concentration range of 10(-7) to 10(-2) mol L(-1). The electrodes show Nernstian slope value of 52.51 ± 0.20 and 51.51 ± 0.25 mV decade(-1) for CPE and PVC membrane electrodes at 30°C, respectively. The potential is nearly stable over the pH range 3.0-6.0 and 2.0-7.0 for CPE and PVC membrane electrodes, respectively. Selectivity coefficient values towards different inorganic cations, sugars, and amino acids reflect high selectivity of the prepared electrodes. The electrodes responses at different temperatures were also studied, and long operational lifetime of 12 and 5 weeks for CPE and PVC membrane electrodes, respectively, were found. These are used for determination of ketotifen fumarate using potentiometric titration, calibration, and standard addition methods in pure samples, its pharmaceutical preparations (Zaditen tablets), and biological fluid (urine). The direct potentiometric determination of KTF using the proposed sensors gave recoveries % of 98.97 ± 0.53 and 98.62 ± 0.74 with RSD 1.42 and 0.63% for CPE and PVC membrane selective electrodes, respectively. Validation of the method shows suitability of the proposed sensors for use in quality control assessment of KTF. The obtained results were in a good agreement with those obtained using the reported spectrophotometric method.

  4. Azo calix[4]arene based neodymium(III)-selective PVC membrane sensor.

    PubMed

    Menon, Shobhana K; Modi, Nishith R; Patel, Bhargav; Patel, Manishkumar B

    2011-02-15

    We found that the PVC membrane, containing azo calix[4]arene is a suitable ionophore, exhibited a Nernstian response for neodymium (Nd(3+)) ions (with slope of 19.8±0.2 mV decade(-1) for the triply charged ion) over a wide linear range of 4.0×10(-8) to 1.0×10(-1) mol L(-1) with a detection limit 1.0×10(-8) mol L(-1), a relatively fast response time, in the whole concentration range (<10 s), and a considerable life time at least for four months in the pH range of 4.0-8.0. Furthermore, the electrode revealed high selectivity with respect to all the common alkali, alkaline earth, transition and heavy metal ions, including the members of the lanthanide family other than Nd(3+). Concerning its applications, it was effectively employed for the determination of neodymium ions in industrial waste water as well as in lake water.

  5. Electrochemical methods for the determination of the diffusion coefficient of ionophores and ionophore-ion complexes in plasticized PVC membranes.

    PubMed

    Bodor, Sándor; Zook, Justin M; Lindner, Erno; Tóth, Klára; Gyurcsányi, Róbert E

    2008-05-01

    The diffusion coefficients of active components in ion-selective membranes have a decisive influence on the life-time and detection limit of the respective ion-selective electrodes, as well as influencing the rate of polarization and relaxation processes of electrically perturbed ion sensors. Therefore, the rational design of mass transport controlled ion-selective electrodes with sub-nanomolar detection limits requires reliable data on the diffusion coefficients. We have implemented electrochemical methods for the quantitative assessment of both the diffusion coefficients of free ionophores and ion-ionophore complexes. The diffusion coefficients of the pH-sensitive chromoionophore ETH 5294 and the calcium-selective ionophore ETH 5234 were determined in plasticized PVC membranes with different PVC to plasticizer ratios. The diffusion coefficient of the free chromoionophore determined by a chronoamperometric method was validated with optical methods for a variety of membrane compositions. The calcium-selective ionophore ETH 5234 was used as a model compound to assess the diffusion coefficient of the ion-ionophore complex calculated from the time required for the complexes to cross a freshly prepared membrane during potentiometric ion-breakthrough experiments. The difference between the diffusion coefficients of the free ionophore ETH 5234 and the ion-ionophore complex was found to be significant and correlated well with the geometry of the respective species.

  6. Dielectric behavior of different nanofillers incorporated in PVC-PMMA based polymer electrolyte membranes

    NASA Astrophysics Data System (ADS)

    Sowmya, G.; Pradeepa, P.; Kalaiselvimary, J.; Edwinraj, S.; Prabhu, M. Ramesh

    2016-05-01

    The Poly (methyl methacrylate) (PMMA)-Poly (vinyl chloride) (PVC) based polymer electrolytes were prepared by solvent casting technique. The prepared polymer electrolytes were subjected to conductivity studies by using electrochemical impedance spectroscopy and the maximum ionic conductivity value was found to be 0.8011 × 10-3 Scm-1 at 303K for PVC (17.5wt%) - PMMA (7.5wt %) - LiClO4 (8wt %) - PC (67wt %) - BaTiO3 (8wt%) electrolyte system. The dielectric behavior of the samples also studied.

  7. PVC membrane sensor for potentiometric determination of iron (II) in some pharmaceutical formulations based on a new neutral ionophore.

    PubMed

    Abounassif, M A; Al-Omar, M A; Amr, A-G E; Mostafa, G A E

    2011-06-01

    A novel poly (vinyl chloride) PVC membrane sensor for Fe(2+) ions is described. The sensor is based on the use of newly synthesized chiral 2,6-bis-(carboxamide methyl ester)pyridine derivative as neutral ionophore in plasticized PVC membrane. The sensor display a fast, stable and near-Nernstian response over a relative wide ferrous concentration range (1 × 10(-3) to 6 × 10(-6) M), with cationic slope of 31.5 ± 0.5, mV per concentration decade over a pH range of 5.0-9.0. The direct determination of 0.25-56.0 µg/ml of ferrous in aqueous solution shows an average recovery of 98.5% and a mean relative standard deviation of 1.5% at 20.0 µg/ml. The sensor displays long life-span, long-term stability, high reproducibility, and short response time. Selectivity coefficients for Fe(II) relative to a number of interfering substances were investigated. The sensor shows high significantly for Fe(2+) over Fe,(3+) Cu,(2+) Zn,(2+) Cd,(2+) Hg,(2+) Pb,(2+) Ni,(2+) Co,(2+) Mn,(2+) Al,(3+) alkaline earth and alkali metal ions. The sensor is successfully applied for measurement of ferrous in drug formulations. The results obtained for the determination of ferrous using the proposed sensor are comparable favourably with those obtained using the spectrophotometric method. Copyright © 2010 John Wiley & Sons, Ltd.

  8. A Novel Sensor for Monitoring of Iron(III) Ions Based on Porphyrins

    PubMed Central

    Vlascici, Dana; Fagadar-Cosma, Eugenia; Popa, Iuliana; Chiriac, Vlad; Gil-Agusti, Mayte

    2012-01-01

    Three A3B porphyrins with mixed carboxy-, phenoxy-, pyridyl-, and dimethoxy-substituent functionalization on the meso-phenyl groups were obtained by multicomponent synthesis, fully characterized and used as ionophores for preparing PVC-based membrane sensors selective to iron(III). The membranes have an ionophore:PVC:plasticizer composition ratio of 1:33:66. Sodium tetraphenylborate was used as additive (20 mol% relative to ionophore). The performance characteristics (linear concentration range, slope and selectivity) of the sensors were investigated. The best results were obtained for the membrane based on 5-(4-carboxyphenyl)-10,15,20-tris(4-phenoxyphenyl)-porphyrin plasticized with bis(2-ethylhexyl)sebacate, in a linear range from 1 × 10−7–1 × 10−1 M with a slope of 21.6 mV/decade. The electrode showed high selectivity with respect to alkaline and heavy metal ions and a response time of 20 s. The influence of pH on the sensor response was studied. The sensor was used for a period of six weeks and the utility has been tested for the quantitative determination of Fe(III) in recovered solutions from spent lithium ion batteries and for the quantitative determination of Fe(III) in tap water samples. PMID:22969395

  9. A novel sensor for monitoring of iron(III) ions based on porphyrins.

    PubMed

    Vlascici, Dana; Fagadar-Cosma, Eugenia; Popa, Iuliana; Chiriac, Vlad; Gil-Agusti, Mayte

    2012-01-01

    Three A(3)B porphyrins with mixed carboxy-, phenoxy-, pyridyl-, and dimethoxy-substituent functionalization on the meso-phenyl groups were obtained by multicomponent synthesis, fully characterized and used as ionophores for preparing PVC-based membrane sensors selective to iron(III). The membranes have an ionophore:PVC:plasticizer composition ratio of 1:33:66. Sodium tetraphenylborate was used as additive (20 mol% relative to ionophore). The performance characteristics (linear concentration range, slope and selectivity) of the sensors were investigated. The best results were obtained for the membrane based on 5-(4-carboxyphenyl)-10,15,20-tris(4-phenoxyphenyl)-porphyrin plasticized with bis(2-ethylhexyl)sebacate, in a linear range from 1 × 10(-7)-1 × 10(-1) M with a slope of 21.6 mV/decade. The electrode showed high selectivity with respect to alkaline and heavy metal ions and a response time of 20 s. The influence of pH on the sensor response was studied. The sensor was used for a period of six weeks and the utility has been tested for the quantitative determination of Fe(III) in recovered solutions from spent lithium ion batteries and for the quantitative determination of Fe(III) in tap water samples.

  10. Construction of Uranyl Selective Electrode Based on Complex of Uranyl Ion with New Ligand Carboxybenzotriazole in PVC Matrix Membrane

    NASA Astrophysics Data System (ADS)

    Abu-Dalo, M. A.; Al-Rawashdeh, N. A. F.; Al-Mheidat, I. R.; Nassory, N. S.

    2015-10-01

    In the present study uranyl selective electrodes in polyvinyl chloride (PVC) matrix membrane were prepared based on a complex of uranyl ion (UO2) with carboxybenzotriazole (CBT) as ligand. The effect of the nature of plasticizer in PVC matrix were evaluated using three different plasticizers, these are dibutyl phthalate (DBP), dioctyl phthalate (DOP) and bis(2-ethylhexyl) sebacate (BHS). The results of this study indicated that the best plasticizer could be used is the DBP, which may be attributed to its lowest viscosity value compared to DOP and BHS. The electrodes with DBP as plasticizer exhibits a Nernstian response with a slope of 28.0 mV/ decade, over a wide range of concentration from 3.0×10-5-6.0×10-2 M and a detection limit of 4.0×10-6 M. It can be used in the pH range of 4.0-10.0 with a response time of less than 10 s for DBP and 25 s for both DOP and BHS. The effects of ions interferences on the electrode response were evaluated. The di- and tri-valent cations were found to interfere less than univalent cations, which was attributed to the high diffusion and the exchange rate between the univalent ions and the uranyl ion solution. The electrodes were characterized by Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron microscopy (SEM). The results of the standard addition method were satisfactory with errors less than 7%. The developed electrode was found to be fast, sensitive and reliable indicated its potential use in measuring the uranly ion concentration in the field.

  11. Novel PVC-membrane electrode for flow injection potentiometric determination of Biperiden in pharmaceutical preparations.

    PubMed

    Khaled, Elmorsy; El-Sabbagh, Inas A; El-Kholy, N G; Ghahni, E Y Abdel

    2011-12-15

    The construction and performance characteristics of Biperiden (BP) polyvinyl chloride (PVC) electrodes are described. Different methods for electrode fabrication are tested including; incorporation of BP-ion pairs (BP-IPs), incorporation of ion pairing agents, or soaking the plain electrode in BP-ion pairs suspension solution. Electrode matrices were optimized referring to the effect of modifier content and nature, plasticizer and the method of modification. The proposed electrodes work satisfactorily in the BP concentration range from 10(-5) to 10(-2)mol L(-1), with fast response time (7s) and adequate operational lifetime (28 days). The electrode potential is pH independent within the range 2.0-7.0, with good selectivity towards BP in presence of various interfering species. The developed electrodes have been applied for potentiometric determination of BP in pharmaceutical formulation under batch and flow injection analysis (FIA) conditions. FIA offers the advantages of accuracy and automation feasibility with high sampling frequency. The dissolution profile for Akineton tablets (2mg BP/tablet) was studied using the proposed electrode in comparison with the official methods.

  12. Release behavior of diethylhexyl phthalate from the polyvinyl-chloride tubing used for intravenous administration and the plasticized PVC membrane.

    PubMed

    Takehisa, Hanawa; Naoko, Endoh; Masahiko, Suzuki; Katsuhide, Terada; Moriyuki, Ohkuma; Keizoh, Sakuta; Mutsuko, Tanaka; Kenji, Kawano; Shin'ichiro, Nakajima; Toshio, Oguchi

    2005-06-13

    The release behavior of diethylhexyl phthalate (DEHP) from polyvinyl-chloride (PVC) tubing, which composes materials in an intravenous administration set, was investigated using polysorbate 80 (Tween 80) aqueous solutions. When Tween 80 solution was circulated in PVC tubing, the amount of DEHP released increased with increasing circulation velocity and temperature. In order to clarify the effect of temperature on the release behavior of DEHP, PVC films containing varying amounts of DEHP were mounted on a cylindrical shaft and rotated at 5 and 40 degrees C. The cumulative amount of DEHP released increased with an increase in temperature, the diffusion coefficients [Dx10(-10) cm2 min-1] at 5 and 40 degrees C were 9.1 and 156.0, respectively. The glass transition temperature (Tg) of PVC films decreased with an increase in DEHP in the PVC film, as measured by differential scanning calorimeter (DSC) and release of DEHP occurred at temperatures above Tg. These results indicate that the release of DEHP from PVC tubing is closely associated with the state of the PVC and is related to diffusion of DEHP throughout the PVC.

  13. PVC membrane electrode for the potentiometric determination of Ipratropium bromide using batch and flow injection techniques.

    PubMed

    Hassouna, M E M; Elsuccary, S A A

    2008-06-15

    Ipratropium (IP(+)) ion-selective electrode (ISE) has been constructed from poly(vinyl chloride) matrix membrane containing Ipratropium-tetraphenylborate (IP-TPB) as the electroactive component using 2-nitrophenyloctylether as plasticizer. The electrode exhibits near Nernstian response to Ipratropium bromide (IPBr) over the concentration range 10(-5) to 10(-2) mol L(-1) and detection limit 5.1x10(-6) mol L(-1). The electrode offers significant advantages including long lifetime (>2 months), excellent stability and reproducibility, fast response time (<10 s), wide pH working range (pH 2-9), high thermal stability (isothermal coefficient 0.37 mV/degrees C) and superior selectivity for IPBr over a large number of inorganic and organic substances. The electrode was successfully used as indicator electrode in the potentiometric titration of IPBr versus sodium tetraphenylborate (NaTPB) and in the determination of IPBr in Atrovent vials and spiked urine samples applying batch and flow injection techniques, with satisfactory results.

  14. Solid phase extraction of zinc(II) using a PVC-based polymer inclusion membrane with di(2-ethylhexyl)phosphoric acid (D2EHPA) as the carrier.

    PubMed

    Kolev, Spas D; Baba, Yoshinari; Cattrall, Robert W; Tasaki, Tsutomu; Pereira, Natalie; Perera, Jilska M; Stevens, Geoffrey W

    2009-05-15

    A polymer inclusion membrane (PIM) is reported consisting of 45% (m/m) di(2-ethylhexyl)phosphoric acid (D2EHPA) immobilized in poly(vinyl chloride) (PVC) for use as a solid phase absorbent for selectively extracting Zn(II) from aqueous solutions in the presence of Cd(II), Co(II), Cu(II), Ni(II) and Fe(II). Interference from Fe(III) in the sample is eliminated by precipitation with orthophosphate prior to the extraction of Zn(II). Studies using a dual compartment transport cell have shown that the Zn(II) flux (2.58 x 10(-6)mol m(-2)s(-1)) is comparable to that observed for supported liquid membranes. The stoichiometry of the extracted complex is shown to be ZnR(2).HR, where R is the D2EHPA anion.

  15. Extraction of Gold(III) from Hydrochloric Acid Solutions with a PVC-based Polymer Inclusion Membrane (PIM) Containing Cyphos(®) IL 104.

    PubMed

    Bonggotgetsakul, Ya Ya Nutchapurida; Cattrall, Robert W; Kolev, Spas D

    2015-12-08

    Poly(vinyl chloride) (PVC) based polymer inclusion membranes (PIMs), with different concentrations of Cyphos® IL 104 as the membrane extractant/carrier, were studied for their ability to extract Au(III) from hydrochloric acid solutions. Some of the PIMs also contained one of the following plasticizers or modifiers: 2-nitrophenyloctyl ether, dioctylphthalate, 1-dodecanol, 1-tetradecanol, or tri(2-ethylhexyl) phosphate. The best performance, in terms of extraction rate and amount of Au(III) extracted, was exhibited by a PIM consisting of 25 wt% Cyphos(®) IL 104, 5 wt% 1-dodecanol, and 70 wt% PVC. An almost complete back-extraction of the Au(III) extracted from this membrane was achieved by using a 0.10 mol L(-1) Na₂SO₃ receiver solution at pH 8. The stoichiometry of the extracted Au(III)/Cyphos® IL 104 adduct was determined as [P]⁺ [AuCl₄](-) H⁺ [PO₂](-) where [P]⁺ and [PO₂](-) represent trihexyl(tetradecyl) phosphonium and bis(2,4,4-trimethylpentyl) phosphinate ions, respectively. Back-extraction of Au(III) is suggested to occur by reduction of Au(III) to Au(I), with the formation of the species [Au(SO₃)₂](3-) in the aqueous receiver solution. Loss of 1-dodecanol from the newly developed PIM to the aqueous solutions in contact with it was observed, which indicated that this membrane was suitable for single use in the efficient recovery of Au(III) from hydrochloric acid solutions of electronic scrap or recycled jewelry.

  16. Extraction of Gold(III) from Hydrochloric Acid Solutions with a PVC-based Polymer Inclusion Membrane (PIM) Containing Cyphos® IL 104

    PubMed Central

    Bonggotgetsakul, Ya Ya Nutchapurida; Cattrall, Robert W.; Kolev, Spas D.

    2015-01-01

    Abstract: Poly(vinyl chloride) (PVC) based polymer inclusion membranes (PIMs), with different concentrations of Cyphos® IL 104 as the membrane extractant/carrier, were studied for their ability to extract Au(III) from hydrochloric acid solutions. Some of the PIMs also contained one of the following plasticizers or modifiers: 2-nitrophenyloctyl ether, dioctylphthalate, 1-dodecanol, 1-tetradecanol, or tri(2-ethylhexyl) phosphate. The best performance, in terms of extraction rate and amount of Au(III) extracted, was exhibited by a PIM consisting of 25 wt% Cyphos® IL 104, 5 wt% 1-dodecanol, and 70 wt% PVC. An almost complete back-extraction of the Au(III) extracted from this membrane was achieved by using a 0.10 mol L−1 Na2SO3 receiver solution at pH 8. The stoichiometry of the extracted Au(III)/Cyphos® IL 104 adduct was determined as [P]+ [AuCl4]− H+ [PO2]− where [P]+ and [PO2]− represent trihexyl(tetradecyl) phosphonium and bis(2,4,4-trimethylpentyl) phosphinate ions, respectively. Back-extraction of Au(III) is suggested to occur by reduction of Au(III) to Au(I), with the formation of the species [Au(SO3)2]3− in the aqueous receiver solution. Loss of 1-dodecanol from the newly developed PIM to the aqueous solutions in contact with it was observed, which indicated that this membrane was suitable for single use in the efficient recovery of Au(III) from hydrochloric acid solutions of electronic scrap or recycled jewelry. PMID:26670259

  17. Comparison of physicochemical and electrochemical characterization of PVC incorporated ZT and ZM composite membranes and their applicability on TMS theoretical equation

    NASA Astrophysics Data System (ADS)

    Arsalan, Mohd; Zeeshan, Mohd; Rafiuddin

    2015-10-01

    PVC incorporated ZT/ZM composite materials have been synthesized via qualitative sol-gel method of material synthesis. Both the composite materials have the combination of inorganic ion-exchanger of different metal salt as well as same organic polymers, which is used to design a new class of organic-inorganic composite ion exchange membrane with much better chemical and mechanical properties, good ion-exchange capacity, higher thermal stability, reproducibility, selectivity etc. The physicochemical, electrochemical, mechanical and thermal properties of both the membranes were characterized by SEM, XRD, FTIR and simultaneous TGA-DTA studies were carried out to understand the ion exchange behavior of materials. The above analysis demonstrated the functional groups, material nature, thermal stability, surface structure, porosity, elemental percentages, ion transportation etc. The electrochemical properties have been studied by TMS theoretical approach which easily determined the important parameters of membranes like transport number, mobility ratio, charge density, charge effectiveness etc. The observed ionic potential and graphical fixed-charge density of both the membranes follows KCl < NaCl < LiCl and KCl > NaCl > LiCl order respectively.

  18. An aluminum selective electrode via modification of PVC membrane by modified clinoptilolite nanoparticles with hexadecyltrimethyl ammonium bromide (HDTMA-Br) surfactant containing Arsenazo III.

    PubMed

    Mahdavi, Mostafa; Nezamzadeh-Ejhieh, Alireza

    2017-05-15

    A modified PVC (polyvinyl chloride) membrane with clinoptilolite nanoparticles/hexadecyltrimethyl ammonium bromide surfactant (HDTMABr)/Arsenazo III: (NSMZ-ARS), was used for construction of Al(III) -selective electrode. The raw and modified samples were characterized by XRD, FTIR, SEM and TEM methods. Among the different tested membranes constructed by raw and modified samples, only, the membrane electrode containing NSMZ-ARS showed a suitable Nernstian response to aluminum in the concentration range of 2.04×10(-5) to 1.99×10(-1)M (r=0.9987), with a detection limit of 1.0×10(-5)molL(-1) and a Nernstian slope of 19.6±0.5mV per decade of aluminum concentration. The electrode response to aluminum remained constant in the pH range of 2-4. The sensor was selective for aluminum over a wide variety of other ions and exhibited. The electrode had a rapid response time and its response reached to steady potential at 5s. The electrode had also satisfactory long term stability and held its activity at least 3months.

  19. Improvements in permeation and fouling resistance of PVC ultrafiltration membranes via addition of Tetronic-1107 and Triton X-100 as two non-ionic and hydrophilic surfactants.

    PubMed

    Rabiee, Hesamoddin; Seyedi, S Mojtaba; Rabiei, Hossein; Alvandifar, Negar

    2016-09-01

    Two non-ionic and hydrophilic surfactant additives, Tetronic-1107 and Triton X-100, were added to poly(vinyl chloride)/NMP polymeric solution to prepare ultrafiltration membranes via immersion precipitation. Surfactants at three different weight percentages up to 6 wt% were added, and the fabricated membranes were characterized and their performance for water treatment in the presence of bovine serum albumin (BSA) as a foulant was assessed. The scanning electron microscopy images indicated remarkable changes in morphology due to higher thermodynamic instability after surfactant addition. The membranes are more porous with more macro-voids in the sub-layer. Plus, the membranes become more hydrophilic. Water flux increases for the modified membranes by nearly two times and the ability of membranes for flux recovery increases from 66% to over 83%. BSA rejection reduces slightly with the addition of surfactants, however this parameter is still almost over 90% for the membranes with the highest amount of surfactants.

  20. Radiation crosslinked plasticized PVC - pipes

    NASA Astrophysics Data System (ADS)

    Hell, Z.; Ravlić, M.; Bogdanović, Lj.; Maleš, J.; Dvornik, I.; Ranogajec, F.; Ranogajec, M.; Tudorić-Ghemo, J.

    The efficiency of polyfunctional monomers triallyl cyanurate, allyl methacrylate, diallyl phtalate, 2-ethyl-2(hydroxy-methyl)-propanediol-(1,3) trimethacrylate, divinyl benzene and ethylene glycol dimethacrylate in radiation crosslinking of PVC was investigated. Patterns of pipes were produced and irradiated with gamma rays. The resistance to internal pressure of crosslinked PVC pipes was measured at 80°C and compared with resistance of unirradiated PVC pipes.

  1. Inhibition of membrane Na(+)-K+ Atpase of the brain, liver and RBC in rats administered di(2-ethyl hexyl) phthalate (DEHP) a plasticizer used in polyvinyl chloride (PVC) blood storage bags.

    PubMed

    Dhanya, C R; Indu, A R; Deepadevi, K V; Kurup, P A

    2003-08-01

    Significant amounts of di(2-ethylhexyl) phthalate (DEHP) leach out into blood stored in DEHP plasticized polyvinyl chloride (PVC) bags resulting in the exposure of recipients of blood transfusion to this compound. The aim of this study was to find out whether DEHP at these low levels has any effect on the activity of membrane Na(+)-K+ ATPase, since a decrease in this enzyme activity has been reported to take place in a number of disorders like neurodegenerative and psychiatric disorders, coronary artery disease and stroke, syndrome-X, tumours etc. DEHP was administered (ip) at a low dose of 750 microg/100 g body weight to rats and the activity of membrane Na(+)-K+ ATPase in liver, brain and RBC was estimated. Histopathology of brain, activity of HMG CoA reductase (a major rate limiting enzyme in the isoprenoid pathway of which digoxin, the physiological inhibitor of Na(+)-K+ ATPase is a product), intracellular concentration of Ca2+ and Mg2+ in RBC (which is altered as a result of inhibition of Na(+)-K+ ATPase) were also studied. (In the light of the observation of increase of intracellular Ca2+ load and intracellular depletion of Mg2+ when Na(+)-K+ ATPase is inhibited). Histopathology of brain revealed areas of degeneration in the rats administered DEHP. There was significant inhibition of membrane Na(+)-K+ ATPase in brain, liver and RBC. Intracellular Ca2+ increased in the RBC while intracellular Mg2+ decreased. However activity of hepatic HMG CoA reductase decreased. Activity of Na(+)-K+ ATPase and HMG CoA reductase, however returned to normal levels within 7 days of stopping administration of DEHP. The inhibition of membrane Na(+)-K+ ATPase activity by DEHP may indicate the possibility of predisposing recipients of transfusion of blood or hemodialysis to the various disorders mentioned above. However since this effect is reversed when DEHP administration is stopped, it may not be a serious problem in the case of a few transfusion; but in patients receiving

  2. PVC: health implications and production trends.

    PubMed Central

    Karstadt, M

    1976-01-01

    Poly(vinyl chloride) (PVC) is a complex plastic system. Individual components of the PVC system, including residual vinyl chloride monomer (RVCM) and certain additives, may pose risks of harm to human health. There have been significant reductions in the RVCM content of PVC resin since 1974, reducing the cancer risk of workers in PVC fabrication plants and consumers of PVC products. A "no-effect" level for vinyl chloride monomer (VCM)-induced carcinogenesis has not been found to date; therefore, the significance of human exposure to low levels of RVCM remains to be determined. Exposure to PVC dust may cause pulmonary dysfunctions. Pulmonary and other possible health effects of PVC dust require further study. The PVC plastics system should be characterized as to interactions among its various components and as to interactions of the components and the PVC system as a whole with biological systems. Images FIGURE 1. FIGURE 2. PMID:799961

  3. Trends in PVC conveyor belting

    SciTech Connect

    Hopwood, J.E.

    1984-03-01

    The development of mechanical systems of extraction at the coal face necessitated the introduction of efficient methods of mineral transportation in deep-mining operations. The most popular system is the belt conveyor. Originally PVC was being evaluated as a rubber substitute, as in its liquid form it appeared to offer an easier route to fabric coating and impregnation for conveyor belt applications. However, it was not until 1950, when over 200 miners lost their lives due to an underground fire being spread by combustible rubber conveyor belts, that the full significance of the properties of PVC were appreciated. Following this tragedy, an intensive development program to produce a substitute for rubber was initiated. It had to have similar operational characteristics as rubber while incorporating the safety features of resistance to flame propagation and build-up of static electrical charges. It became evident that PVC could be compounded to realize these requirements and belting manufacturers immediately started to produce a new generation of belts based on the previouly proven mechanical characteristics of multiply fabrics, but substituting PVC for the rubber content. The advantages of PVC are discussed.

  4. Reconstruction of Extracellular Respiratory Pathways for Iron(III) Reduction in Shewanella Oneidensis Strain MR-1

    PubMed Central

    Coursolle, Dan; Gralnick, Jeffrey A.

    2012-01-01

    Shewanella oneidensis strain MR-1 is a facultative anaerobic bacterium capable of respiring a multitude of electron acceptors, many of which require the Mtr respiratory pathway. The core Mtr respiratory pathway includes a periplasmic c-type cytochrome (MtrA), an integral outer-membrane β-barrel protein (MtrB), and an outer-membrane-anchored c-type cytochrome (MtrC). Together, these components facilitate transfer of electrons from the c-type cytochrome CymA in the cytoplasmic membrane to electron acceptors at and beyond the outer-membrane. The genes encoding these core proteins have paralogs in the S. oneidensis genome (mtrB and mtrA each have four while mtrC has three) and some of the paralogs of mtrC and mtrA are able to form functional Mtr complexes. We demonstrate that of the additional three mtrB paralogs found in the S. oneidensis genome, only MtrE can replace MtrB to form a functional respiratory pathway to soluble iron(III) citrate. We also evaluate which mtrC/mtrA paralog pairs (a total of 12 combinations) are able to form functional complexes with endogenous levels of mtrB paralog expression. Finally, we reconstruct all possible functional Mtr complexes and test them in a S. oneidensis mutant strain where all paralogs have been eliminated from the genome. We find that each combination tested with the exception of MtrA/MtrE/OmcA is able to reduce iron(III) citrate at a level significantly above background. The results presented here have implications toward the evolution of anaerobic extracellular respiration in Shewanella and for future studies looking to increase the rates of substrate reduction for water treatment, bioremediation, or electricity production. PMID:22363330

  5. Electrospinning of PVC with natural rubber

    NASA Astrophysics Data System (ADS)

    Othman, Muhammad Hariz; Mohamed, Mahathir; Abdullah, Ibrahim

    2013-11-01

    Polyvinyl chloride (PVC) was mixed with natural rubbers which are liquid natural rubber (LNR), liquid epoxidised natural rubber (LENR) and liquid epoxidised natural rubber acrylate (LENRA) for a preparation of a fine non-woven fiber's mat. PVC and each natural rubbers(PVC:LENR, PVC:LNR and PVC:LENRA) were mixed based on ratio of 70:30. Electrospinning method was used to prepare the fiber. The results show that the spinnable concentration of PVC/ natural rubber/THF solution is 16 wt%. The morphology, diameter, structure and degradation temperature of electrospun fibers were investigated by scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). SEM photos showed that the morphology and diameter of the fibers were mainly affected by the addition of natural rubber. TGA results suggested that PVC electrospun fiber has higher degradation temperature than those electrospun fibers that contain natural rubber.

  6. Electrospinning of PVC with natural rubber

    SciTech Connect

    Othman, Muhammad Hariz; Abdullah, Ibrahim; Mohamed, Mahathir

    2013-11-27

    Polyvinyl chloride (PVC) was mixed with natural rubbers which are liquid natural rubber (LNR), liquid epoxidised natural rubber (LENR) and liquid epoxidised natural rubber acrylate (LENRA) for a preparation of a fine non-woven fiber’s mat. PVC and each natural rubbers(PVC:LENR, PVC:LNR and PVC:LENRA) were mixed based on ratio of 70:30. Electrospinning method was used to prepare the fiber. The results show that the spinnable concentration of PVC/ natural rubber/THF solution is 16 wt%. The morphology, diameter, structure and degradation temperature of electrospun fibers were investigated by scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). SEM photos showed that the morphology and diameter of the fibers were mainly affected by the addition of natural rubber. TGA results suggested that PVC electrospun fiber has higher degradation temperature than those electrospun fibers that contain natural rubber.

  7. Thermal degradation of PVC: A review.

    PubMed

    Yu, Jie; Sun, Lushi; Ma, Chuan; Qiao, Yu; Yao, Hong

    2016-02-01

    This review summarized various chemical recycling methods for PVC, such as pyrolysis, catalytic dechlorination and hydrothermal treatment, with a view to solving the problem of energy crisis and the impact of environmental degradation of PVC. Emphasis was paid on the recent progress on the pyrolysis of PVC, including co-pyrolysis of PVC with biomass/coal and other plastics, catalytic dechlorination of raw PVC or Cl-containing oil and hydrothermal treatment using subcritical and supercritical water. Understanding the advantage and disadvantage of these treatment methods can be beneficial for treating PVC properly. The dehydrochlorination of PVC mainly happed at low temperature of 250-320°C. The process of PVC dehydrochlorination can catalyze and accelerate the biomass pyrolysis. The intermediates from dehydrochlorination stage of PVC can increase char yield of co-pyrolysis of PVC with PP/PE/PS. For the catalytic degradation and dechlorination of PVC, metal oxides catalysts mainly acted as adsorbents for the evolved HCl or as inhibitors of HCl formation depending on their basicity, while zeolites and noble metal catalysts can produce lighter oil, depending the total number of acid sites and the number of accessible acidic sites. For hydrothermal treatment, PVC decomposed through three stages. In the first region (T<250°C), PVC went through dehydrochlorination to form polyene; in the second region (250°C

  8. Nest relocation using PVC "spotters"

    USGS Publications Warehouse

    Simon, John C.

    1998-01-01

    A simple device to aid in the rapid relocation of nests, composed on PVC pipe and tie wire, is described. A 16-18 cm length of pipe can be attached to a supporting structure with a section of wire and adjusted to point at the target nest by its discoverer. Used like an lensless spotting scope, the “spotter” allows other observers to quickly and reliably relocate the nest with minimal written or verbal description.

  9. Morphological studies of DBSA-doped polyaniline/PVC blends.

    PubMed

    Afzal, Asma Binat; Akhtar, Muhammad Javed; Ahmad, Maqsood

    2010-01-01

    Solution blending technique has been used to synthesize dodecylbenzenesulfonic acid (DBSA)-doped polyaniline (PAND)/poly-vinyl chloride (PVC) blends by two methods, namely redoping method (PANDR/PVC blends) and aqueous polymerization method (PANDA/PVC blends). PANDR/PVC blends show improved mechanical properties as compared to PANDA/PVC blends, which show brittle nature of the films. However, by increasing concentration of PANDR in the PVC matrix, PANDR/PVC blend films are becoming more rigid due to increases in the modulus of elasticity. Irradiation of blend samples by electron beam used during scanning electron microscopy (SEM) analyses has changed the morphology of PANDA/PVC blend films due to dehydrochlorination of free PVC, whereas PANDR/PVC blends remain unaffected during irradiation by electron beam.

  10. Evaporation kinetics of DIDP plasticizer from PVC

    NASA Astrophysics Data System (ADS)

    Djouani, Fatma; Mkacher, Inès; Colin, Xavier; Brument, Yves; Cristiano-Tassi, Antonella

    2014-05-01

    The physical loss of diisodecyl phthalate (DIDP) plasticizer from PVC films of about 50 μm thickness has been investigated between 95 and 160°C in air by FTIR spectrophotometry and gravimetry. Complementary OIT measurements have been performed to follow the stabilizer depletion and to confirm that the dehydrochlorination of PVC remains negligible for all exposure durations under study. As expected for thin PVC films, the overall loss kinetics obeys a first order law, indicating that it is controlled by DIDP evaporation. The corresponding coefficient of DIDP evaporation obeys an Arrhenius law with an activation energy of about 96 kJ mol-1. These results are in good agreement with those previously reported in the literature for other types of phthalate plasticizers of PVC.

  11. Development of an optode for detection of trace amounts of Hg2+ in different real samples based on immobilization of novel tetradentate Schiff bases bearing two thiol groups in PVC membrane.

    PubMed

    Aziz, Ayman A Abdel; Mohammed, Soha F; El Gamel, Magdy M

    2014-05-01

    A very sensitive and reversible optical chemical sensor based on a novel tetradentate Schiff base namely N.N(/)bis(2-aminothiophenol)benzene-1,2-dicarboxaldehyde (ATBD) immobilized within a plasticized PVC film for Hg(2+) determination is described. At optimum conditions (i.e. pH 6.0), the proposed sensor displayed a linear response to Hg(2+) over 1.0 × 10(-10) - 1.0 × 10(-2) mol L(-1) with a limit of detection of 7.23 × 10(-11) mol L(-1) (0.0145 μgL(-1)). Moreover, the results revealed that, under batch condition, the sensor is fully reversible within a response time ~ 35 s. In addition to its high stability and reproducibility, the sensor showed good selectivity towards Hg(2+) ion with respect to common metal cations. The sensor was successfully applied for determination of Hg(2+) ion in some real samples, including hair, urine and well water samples. The results were in good correlation with the data obtained using cold vapor atomic absorption spectrometry.

  12. A copper(II)-selective PVC membrane electrode based on a macrocyclic ligand, 1,2,5,6,8,11-hexaazacyclododeca-7,12-dione-2,4,8,10-tetraene.

    PubMed

    Chandra, Sulekh; Singh, Chandan Kumar; Agarwal, Himanshu; Agarwal, Ram K

    2007-06-01

    An attempt has been made to develop a highly selective Cu2+-ion selective electrode based on a poly(vinyl chloride) based sensor using 1,2,5,6,8,11-hexaazacyclododeca-7,12-dione-2,4,8,10-tetraene as ionophore with 61.5% DBP in the presence of 29% PVC, 4.5% ionophore and 5% NaTBP as an anion excluder. The sensor exhibits a near Nernstian potential response of 29.5 +/- 0.3 mV per decade over a wide concentration range (2.0 x 10(-7) - 1 x 10(-1) M) with a detection limit of 8.1 x 10(-8) M between pH 3 - 11 with a fast response time of < 5 s. The selectivity coefficient values, as determined by the matched potential method (MPM), indicate excellent selectivity for Cu(II) ions over a large number of ions. The proposed sensor exhibits an adequate shelf life (4 - 5 months) with good reproducibility. The quantification of Cu(II) in electroplating wastewater and various brands of Indian tea was successfully achieved using the proposed sensor.

  13. Poly(vinyl alcohol)/poly(vinyl chloride) composite polymer membranes for secondary zinc electrodes

    NASA Astrophysics Data System (ADS)

    Yang, Chun-Chen; Yang, Jen Ming; Wu, Cheng-Yeou

    A microporous composite polymer membrane composed of poly(vinyl alcohol) (PVA) and poly(vinyl chloride) (PVC), was prepared by a solution casting method and a partial dissolution process. The characteristic properties of microporous PVA/PVC composite polymer membranes containing 2.5-10 wt.% PVC polymers as fillers were characterized by thermogravimetric analysis (TGA), X-ray diffraction (XRD), scanning electron microscopy (SEM), capillary flow porometry (CFP), micro-Raman spectroscopy, dynamic mechanical analyzer (DMA) and the AC impedance method. The electrochemical properties of a secondary Zn electrode with the PVA/PVC composite polymer membrane were studied using the galvanostatic charge/discharge method. The PVA/PVC composite polymer membrane showed good thermal, mechanical and electrochemical properties. As a result, the PVA/PVC composite polymer membrane appears to be a good candidate for use on the secondary Zn electrodes.

  14. Rapid quenching effects in PVC films

    NASA Technical Reports Server (NTRS)

    Lee, H. D.; Mandell, J. F.; Mcgarry, F. J.

    1981-01-01

    Using a specially constructed microbalance for hydrostatic weighing, density changes in PVC thin films (with no additives, 30-100 micrometers thick), due to rapid quenching (approximately 300 C/sec) through the glass transition temperature, have been observed. The more severe the quench, the greater is the free volume content. Isobaric volume recovery of PVC has also been studied by volume dilatometry. Both show aging of relaxing molecular rearrangements takes place as a linear function of logarithmic aging time at room temperature. Distribution of retardation times and Primak's distributed activation energy spectra have been applied to the volume recovery data. The concomitant changes in mechanical properties of PVC after quenching have been monitored by tensile creep and stress-strain to failure. All reflect the presence of excess free volume content, due to rapid quenching.

  15. Superhydrophobic Materials Technology-PVC Bonding Techniques

    SciTech Connect

    Hunter, Scott R.; Efird, Marty

    2013-05-03

    The purpose of the technology maturation project was to develop an enhanced application technique for applying diatomaceous earth with pinned polysiloxane oil to PVC pipes and materials. The oil infiltration technique is applied as a spray of diluted oil in a solvent onto the superhydrophobic diatomaceous earth substrate. This makes the surface take on the following characteristics: wet-cleanable; anti-biofouling; waterproof; and anti-corrosion. The project involved obtaining input and supplies from VeloxFlow and the development of successful techniques that would quickly result in a commercial license agreement with VeloxFlow and other companies that use PVC materials in a variety of other fields of use.

  16. Properties of lightweight aggregate concrete prepared with PVC granules derived from scraped PVC pipes.

    PubMed

    Kou, S C; Lee, G; Poon, C S; Lai, W L

    2009-02-01

    This paper aims to investigate the fresh and hardened properties of lightweight aggregate concretes that are prepared with the use of recycled plastic waste sourced from scraped PVC pipes to replace river sand as fine aggregates. A number of laboratory prepared concrete mixes were tested, in which river sand was partially replaced by PVC plastic waste granules in percentages of 0%, 5%, 15%, 30% and 45% by volume. Two major findings are identified. The positive side shows that the concrete prepared with a partial replacement by PVC was lighter (lower density), was more ductile (greater Poisson's ratios and reduced modulus of elasticity), and had lower drying shrinkage and higher resistance to chloride ion penetration. The negative side reveals that the workability, compressive strength and tensile splitting strength of the concretes were reduced. The results gathered would form a part of useful information for recycling PVC plastic waste in lightweight concrete mixes.

  17. Polarizing PVC — A Discrepant Event

    NASA Astrophysics Data System (ADS)

    Headly, David; Karabatek, Mohamed

    2016-01-01

    Each year when teaching polarization phenomena and the Triboelectric Series in a unit on electrostatics, I would balance some rods (2-3 ft in length) made from wood, aluminum, PVC, and Plexiglas on an inverted watch glass and demonstrate to the class how a party balloon rubbed with fake rabbit fur (charging the balloon negative) would always attract the uncharged rods, causing them to rotate towards the balloon (see Fig. 1). The fact that a charged object always attracts a neutral object due to the induced dipole in the latter is a great way to test if something is in fact charged. Surprisingly, the PVC pipe would usually, but not always, repel the charged balloon and rotate away! Repulsion means that neither of the objects are electrically neutral. In a separate test, after rubbing together a Plexiglas rod with a polyethylene grocery bag (making the rod positively charged and the bag negatively charged), the PVC usually attracts the rod. With the help of a student as part of his senior project, I finally decided to investigate further the source of the negative charge that exists on PVC. Specifically, is it nothing more than static charge that builds up on the pipe from unavoidable contact with its surroundings, or is it somehow intrinsic to the manufacturing process?

  18. Polarizing PVC--A Discrepant Event

    ERIC Educational Resources Information Center

    Headly, David; Karabatek, Mohamed

    2016-01-01

    This article describes an experiment teaching polarization phenomena and the Triboelectric Series in a unit on electrostatics. Using rods (2-3 ft in length) made from wood, aluminum, PVC, and Plexiglas on an inverted watch glass, these items demonstrated to the class how a party balloon rubbed with fake rabbit fur (charging the balloon negative)…

  19. Novel creatine biosensors based on all solid-state contact ammonium-selective membrane electrodes.

    PubMed

    Altikatoglu, Melda; Karakus, Emine; Erci, Vildan; Pekyardımcı, Sule; Isildak, Ibrahim

    2013-04-01

    Novel creatine bienzymatic potentiometric biosensors were prepared by immobilizing urease and creatinase on all solid-state contact PVC-containing palmitic acid and carboxylated PVC matrix membrane ammonium-selective electrodes without inner reference solution. Potentiometric characteristics of biosensors were examined in physiological model solutions at different creatine concentrations. The linear working range and long-term sensitivity of the biosensors were also determined. The creatine biosensors prepared by using the carboxylated PVC membrane electrodes showed more effective performance than those of the PVC containing palmitic acid membrane electrodes. Creatine assay in serum samples was successfully carried out by using the standard addition method.

  20. Magneto-Structural Analysis of Iron(III) Keggin Polyoxometalates.

    PubMed

    Bandeira, Nuno A G; Sadeghi, Omid; Woods, Toby J; Zhang, Yuan-Zhu; Schnack, Jürgen; Dunbar, Kim; Nyman, May; Bo, Carles

    2017-02-16

    A computational study and magnetic susceptibility measurements of three homonuclear Fe(III) Keggin structures are herein presented: the [FeO4@Fe12F24(μ-OCH3)12](5-) anion (1), the [Bi6{FeO4@Fe12O12(OH)12}(μ-O2CCCl3)12](+) cation (2) and its polymorph [Bi6{FeO4@Fe12O12(OH)10(H2O)2}(μ-O2CCF3)10](3+) (3). These results are contrasted with the exchange interactions present in the previously characterized [Fe6(OH)3Ge2W18O68(OH)6](11-) and [H12As4Fe8W30O120(H2O)2](4-) anions. The computational analysis shows that the most significant antiferromagnetic spin coupling takes place at the junction between each of the {Fe3O6(OH)3}/{Fe3F6(OCH3)3} framework motifs, a possibility that had been previously discarded in the literature on the basis of the Fe-Fe distances. For all the examined iron(III) Keggin structures, it is found that the magnitude of the magnetic couplings within each structural subunit follows the same trend.

  1. Determination of traces of iron(II) in the presence of iron(III) by the bathophenanthroline method.

    PubMed

    Mizuno, T

    1972-03-01

    Traces of iron(II) (1-30 ppM) in the presence of iron(III) were determined (error <10%) by the bathophenanthroline method. Interference of iron(III) was eliminated by masking with sodium pyrophosphate (2.5-60 mg). The iron(II) complex was extracted with n-butanol, at pH 4.2-4.7.

  2. A novel PVC-membrane optical sensor for highly sensitive and selective determination of UO 22+ ion based on a recently synthesized benzo-substituted macrocyclic diamide and dibenzoylmethane

    NASA Astrophysics Data System (ADS)

    Shamsipur, Mojtaba; Zargoosh, Kiomars; Mizani, Farhang; Eshghi, Hossein; Rostami, Faramarz

    2010-09-01

    A highly sensitive ion-selective bulk optode membrane for sensing UO 22+ ion based on plasticized poly(vinyl chloride) containing 6,7,9,10,12,13,15,16,23,24,25,26-dodecahydrodibenzo[n,v][1,4,7,10,13,17,20]pentaoxa-diazacyclotricosine-22,27-dione as ionophore, dibenzodylmethane as chromoionophore and sodium tetraphenylborate as an ionic additive was prepared. In addition to its high stability, reproducibility and relatively long lifetime, the proposed optical sensor revealed good selectivity for uranyl ion over a large number of alkali, alkaline earth, transition, and heavy metal ions. The proposed sensor displays a calibration response for UO 22+ over a concentration range of 4.3 × 10 -6 to 2.5 × 10 -8 M with a limit of detection of 8.0 × 10 -9 M and a response time of less than 12 min. The proposed optical sensor was applied successfully to the determination of UO 22+ ion in tap water and Khoshumi mine concentrated solution samples.

  3. Photo-induced spin transition of Iron(III) compounds with pi-pi intermolecular interactions.

    PubMed

    Hayami, Shinya; Hiki, Kenji; Kawahara, Takayoshi; Maeda, Yonezo; Urakami, Daisuke; Inoue, Katsuya; Ohama, Mitsuo; Kawata, Satoshi; Sato, Osamu

    2009-01-01

    Iron(III) spin-crossover compounds [Fe(pap)(2)]ClO(4) (1), [Fe(pap)(2)]BF(4) (2), [Fe(pap)(2)]PF(6) (3), [Fe(qsal)(2)]NCS (4), and [Fe(qsal)(2)]NCSe (5) (Hpap=2-(2-pyridylmethyleneamino)phenol and Hqsal=2-[(8-quinolinylimino)methyl]phenol) were prepared and their spin-transition properties investigated by magnetic susceptibility and Mössbauer spectroscopy measurements. The iron(III) compounds exhibited spin transition with thermal hysteresis. Single crystals of the iron(III) compounds were obtained as suitable solvent adducts for X-ray analysis, and structures in high-spin (HS) and low-spin (LS) states were revealed. Light-induced excited-spin-state trapping (LIESST) effects of the iron(III) compounds were induced by light irradiation at 532 nm for 1-3 and at 800 nm for 4 and 5. The activation energy E(a) and the low-temperature tunneling rate k(HL)(T-->0) of iron(III) LIESST compound 1 were estimated to be 1079 cm(-1) and 2.4x10(-8) s(-1), respectively, by HS-->LS relaxation experiments. The Huang-Rhys factor S of 1 was also estimated to be 50, which was similar to that expected for iron(II) complexes. It is thought that the slow relaxation in iron(III) systems is achieved by the large structural distortion between HS and LS states. Introduction of strong intermolecular interactions, such as pi-pi stacking, can also play an important role in the relaxation behavior, because it can enhance the structural distortion of the LIESST complex.

  4. Facile grafting of bioactive cellulose derivatives onto PVC surfaces

    NASA Astrophysics Data System (ADS)

    Bigot, Sandra; Louarn, Guy; Kébir, Nasreddine; Burel, Fabrice

    2013-10-01

    Bioactive methyl cellulose and hydroxyethyl cellulose were successfully grafted onto PVC films using a two-step pathway. PVC surface was first modified with isothiocyanate in DMSO/water medium. Then, unmodified polysaccharides were directly grafted onto the thiocyanated surface in acetonitrile/DMSO mixture, in presence of DBTL as catalyst. The polysaccharide grafting onto the PVC surface was evidenced by contact angle measurements, AFM and XPS.

  5. Polyaniline nanorods/PVC composites with antistatic properties

    NASA Astrophysics Data System (ADS)

    Tao, Yulun; Feng, Weitao; Ding, Guoxin; Cheng, Guojun

    2015-08-01

    Novel antistatic polyaniline/poly(vinyl chloride) (PVC) composite materials are prepared. This study focuses on modification of PVC matrix with different content of polyaniline nanorods. Polyaniline nanorods can reduce the volumn resistivity of PVC/polyaniline composites 1016 Ω cm from to 1011 Ω cm five orders of magnitude at low content of 2 wt %. Moreover, the mechanical performance of the composite material is also good. Based on the results, we have confidence in the new antistatic composites.

  6. Kinetics and Mechanism of Iodide Oxidation by Iron(III): A Clock Reaction Approach

    ERIC Educational Resources Information Center

    Bauer, Jurica; Tomisic, Vladislav; Vrkljan, Petar B. A.

    2008-01-01

    A simple method for studying the kinetics of a chemical reaction is described and the significance of reaction orders in deducing reaction mechanisms is demonstrated. In this student laboratory experiment, oxidation of iodide by iron(III) ions in an acidic medium is transformed into a clock reaction. By means of the initial rates method, it is…

  7. Synthesis and iron(III) binding properties of 3-hydroxypyrid-4-ones derived from kojic acid.

    PubMed

    Molenda, J J; Basinger, M A; Hanusa, T P; Jones, M M

    1994-08-01

    In an attempt to reduce the toxicity of the 3-hydroxypyrid-4-ones, the more hydrophilic derivatives of kojic acid were explored and compared to the standard, 1,2-dimethyl-3-hydroxypyrid-4-one, L1. The synthesis and iron(III) binding properties of these chelators are described. Neither these compounds nor the clinically effective 1,2-dimethyl-3-hydroxypyrid-4 one is able to completely remove all of the iron(III) from the Fe(III)EDTA complex in sodium acetate buffered solutions, when the 3-hydroxypyrid-4-one: Fe(III) ratio is 6:1. The ability of these compounds to enhance the urinary excretion of iron in rats indicates that the behavior of the 3-hydroxypyrid-4-ones derived from kojic acid is comparable to the analogous derivatives of maltol and ethyl maltol. The structure of the iron(III) complex of 3-hydroxy-6-hydroxymethyl-1-methylpyrid-4-one was determined by x-ray diffraction and found to be similar to the previously reported structure of the iron(III) complex of L1.

  8. Experimental and Computational Evidence for the Mechanism of Intradiol Catechol Dioxygenation by Non-Heme Iron(III) Complexes

    PubMed Central

    Jastrzebski, Robin; Quesne, Matthew G; Weckhuysen, Bert M; de Visser, Sam P; Bruijnincx, Pieter C A

    2014-01-01

    Catechol intradiol dioxygenation is a unique reaction catalyzed by iron-dependent enzymes and non-heme iron(III) complexes. The mechanism by which these systems activate dioxygen in this important metabolic process remains controversial. Using a combination of kinetic measurements and computational modelling of multiple iron(III) catecholato complexes, we have elucidated the catechol cleavage mechanism and show that oxygen binds the iron center by partial dissociation of the substrate from the iron complex. The iron(III) superoxide complex that is formed subsequently attacks the carbon atom of the substrate by a rate-determining C=O bond formation step. PMID:25322920

  9. Effects of irradiation on PVC compounds

    NASA Astrophysics Data System (ADS)

    Bataille, P.; Ulkem, I.; Schreiber, H. P.

    1995-11-01

    PVC compounds containing CaCO 3 filler and plasticizers were prepared with or without a trifunctional acrylic crosslinking agent and irradiated by 60Co γ-rays under air or nitrogen atmosphere. The samples without crosslinking agent did not respond to irradiation. The mechanical properties of the other samples such as tensile strength, yield strength and % elongation showed a great sensitivity to irradiation. Lower values of Young's modulus were observed for samples irradiated in air compared with samples irradiated in nitrogen indicating the effect of atmosphere in the range of irradiation studied.

  10. PET and PVC Separation with Hyperspectral Imagery

    PubMed Central

    Moroni, Monica; Mei, Alessandro; Leonardi, Alessandra; Lupo, Emanuela; La Marca, Floriana

    2015-01-01

    Traditional plants for plastic separation in homogeneous products employ material physical properties (for instance density). Due to the small intervals of variability of different polymer properties, the output quality may not be adequate. Sensing technologies based on hyperspectral imaging have been introduced in order to classify materials and to increase the quality of recycled products, which have to comply with specific standards determined by industrial applications. This paper presents the results of the characterization of two different plastic polymers—polyethylene terephthalate (PET) and polyvinyl chloride (PVC)—in different phases of their life cycle (primary raw materials, urban and urban-assimilated waste and secondary raw materials) to show the contribution of hyperspectral sensors in the field of material recycling. This is accomplished via near-infrared (900–1700 nm) reflectance spectra extracted from hyperspectral images acquired with a two-linear-spectrometer apparatus. Results have shown that a rapid and reliable identification of PET and PVC can be achieved by using a simple two near-infrared wavelength operator coupled to an analysis of reflectance spectra. This resulted in 100% classification accuracy. A sensor based on this identification method appears suitable and inexpensive to build and provides the necessary speed and performance required by the recycling industry. PMID:25609050

  11. Cell adhesion to plasma-coated PVC.

    PubMed

    Rangel, Elidiane C; de Souza, Eduardo S; de Moraes, Francine S; Duek, Eliana A R; Lucchesi, Carolina; Schreiner, Wido H; Durrant, Steven F; Cruz, Nilson C

    2014-01-01

    To produce environments suitable for cell culture, thin polymer films were deposited onto commercial PVC plates from radiofrequency acetylene-argon plasmas. The proportion of argon in the plasmas, P(Ar), was varied from 5.3 to 65.8%. The adhesion and growth of Vero cells on the coated surfaces were examined for different incubation times. Cytotoxicity tests were performed using spectroscopic methods. Carbon, O, and N were detected in all the samples using XPS. Roughness remained almost unchanged in the samples prepared with 5.3 and 28.9% but tended to increase for the films deposited with P(Ar) between 28.9 and 55.3%. Surface free energy increased with increasing P(Ar), except for the sample prepared at 28.9% of Ar, which presented the least reactive surface. Cells proliferated on all the samples, including the bare PVC. Independently of the deposition condition there was no evidence of cytotoxicity, indicating the viability of such coatings for designing biocompatible devices.

  12. Cell Adhesion to Plasma-Coated PVC

    PubMed Central

    Rangel, Elidiane C.; de Souza, Eduardo S.; de Moraes, Francine S.; Duek, Eliana A. R.; Lucchesi, Carolina; Schreiner, Wido H.; Durrant, Steven F.; Cruz, Nilson C.

    2014-01-01

    To produce environments suitable for cell culture, thin polymer films were deposited onto commercial PVC plates from radiofrequency acetylene-argon plasmas. The proportion of argon in the plasmas, PAr, was varied from 5.3 to 65.8%. The adhesion and growth of Vero cells on the coated surfaces were examined for different incubation times. Cytotoxicity tests were performed using spectroscopic methods. Carbon, O, and N were detected in all the samples using XPS. Roughness remained almost unchanged in the samples prepared with 5.3 and 28.9% but tended to increase for the films deposited with PAr between 28.9 and 55.3%. Surface free energy increased with increasing PAr, except for the sample prepared at 28.9% of Ar, which presented the least reactive surface. Cells proliferated on all the samples, including the bare PVC. Independently of the deposition condition there was no evidence of cytotoxicity, indicating the viability of such coatings for designing biocompatible devices. PMID:25247202

  13. PET and PVC separation with hyperspectral imagery.

    PubMed

    Moroni, Monica; Mei, Alessandro; Leonardi, Alessandra; Lupo, Emanuela; Marca, Floriana La

    2015-01-20

    Traditional plants for plastic separation in homogeneous products employ material physical properties (for instance density). Due to the small intervals of variability of different polymer properties, the output quality may not be adequate. Sensing technologies based on hyperspectral imaging have been introduced in order to classify materials and to increase the quality of recycled products, which have to comply with specific standards determined by industrial applications. This paper presents the results of the characterization of two different plastic polymers--polyethylene terephthalate (PET) and polyvinyl chloride (PVC)--in different phases of their life cycle (primary raw materials, urban and urban-assimilated waste and secondary raw materials) to show the contribution of hyperspectral sensors in the field of material recycling. This is accomplished via near-infrared (900-1700 nm) reflectance spectra extracted from hyperspectral images acquired with a two-linear-spectrometer apparatus. Results have shown that a rapid and reliable identification of PET and PVC can be achieved by using a simple two near-infrared wavelength operator coupled to an analysis of reflectance spectra. This resulted in 100% classification accuracy. A sensor based on this identification method appears suitable and inexpensive to build and provides the necessary speed and performance required by the recycling industry.

  14. Cloning and sequence of cymA, a gene encoding a tetraheme cytochrome c required for reduction of iron(III), fumarate, and nitrate by Shewanella putrefaciens MR-1.

    PubMed Central

    Myers, C R; Myers, J M

    1997-01-01

    The cymA gene, which encodes a tetraheme cytochrome c, was cloned from Shewanella putrefaciens MR-1. This gene complemented a mutant which had a TnphoA insertion in cymA and which was deficient in the respiratory reduction of iron(III), nitrate, fumarate, and manganese(IV). The 561-bp nucleotide sequence of cymA encodes a protein of 187 amino acids with a predicted molecular mass of 20.8 kDa. No N-terminal signal sequence was readily apparent; consistent with this, a cytochrome with a size of 21 kDa was detected in the wild type but was absent in the insertional mutant. The cymA gene is transcribed into an mRNA; the major transcript was approximately 790 bases, suggesting that it is not part of a multicistronic operon. This RNA transcript was not detected in the cymA mutant. The CymA protein was found in the cytoplasmic membrane and soluble fraction of MR-1, and it shares partial amino acid sequence homology with multiheme c-type cytochromes from other bacteria. These cytochromes are ostensibly involved in the transfer of electrons from the cytoplasmic membrane to acceptors in the periplasm. The localization of the fumarate and iron(III) reductases to the periplasm and outer membrane of MR-1, respectively, suggests the possibility of a similar electron transfer role for CymA. PMID:9023196

  15. FTIR studies of PVC/PMMA blend based polymer electrolytes

    NASA Astrophysics Data System (ADS)

    Ramesh, S.; Leen, Koay Hang; Kumutha, K.; Arof, A. K.

    2007-04-01

    The polymer electrolytes composing of the blend of polyvinyl chloride-polymethyl methacrylate (PVC/PMMA) with lithium triflate (LiCF 3SO 3) as salt, ethylene carbonate (EC) and dibutyl phthalate (DBP) as plasticizers and silica (SiO 2) as the composite filler were prepared. FTIR studies confirm the complexation between PVC/PMMA blends. The C sbnd Cl stretching mode at 834 cm -1 for pure PVC is shifted to 847 cm -1 in PVC-PMMA-LiCF 3SO 3 system. This suggests that there is interaction between Cl in PVC with Li + ion from LiCF 3SO 3. The band due to sbnd OCH 3 at 1150 cm -1 for PVC-PMMA blend is shifted to 1168 cm -1 in PVC-PMMA-LiCF 3SO 3 system. This shift is expected to be due to the interaction between Li + ion and the oxygen atom in PMMA. The symmetric vibration band and the asymmetric vibration band of LiCF 3SO 3 at 1033 and 1256 cm -1 shifted to 1075 and 1286 cm -1 in the DBP-EC plasticized PVC-PMMA-LiCF 3SO 3 complexes. The interaction between Li + ions and SiO 2 will lead to an increase in the number of free plasticizers (which does not interact with Li + ions). When the silica content increases from 2% to 5%, the intensity of the peak at 896 cm -1 (due to the ring breathing vibration of free EC) increases in PVC-PMMA-LiCF 3SO 3-DBP-EC system.

  16. Functional initiators for both ATRP and ROP catalyzed by iron(III) catalyst

    NASA Astrophysics Data System (ADS)

    Li, J.; Yang, C.; Cheng, C. J.

    2016-07-01

    α-Trichloromethyl benzyl alcohol was successfully used as initiators for both AGET ATRP and ROP reactions, which was catalyzed by only one non-toxic and very cheap catalyst iron(III) chloride. The corresponding polymers PMMA and PCL were characterized by 1H NMR, and their molecular mass were calculated as 7.53 kDa and 10.08 kDa, respectively.

  17. Zeta-Fe2O3 - A new stable polymorph in iron(III) oxide family

    NASA Astrophysics Data System (ADS)

    Tuček, Jiří; Machala, Libor; Ono, Shigeaki; Namai, Asuka; Yoshikiyo, Marie; Imoto, Kenta; Tokoro, Hiroko; Ohkoshi, Shin-Ichi; Zbořil, Radek

    2015-10-01

    Iron(III) oxide shows a polymorphism, characteristic of existence of phases with the same chemical composition but distinct crystal structures and, hence, physical properties. Four crystalline phases of iron(III) oxide have previously been identified: α-Fe2O3 (hematite), β-Fe2O3, γ-Fe2O3 (maghemite), and ɛ-Fe2O3. All four iron(III) oxide phases easily undergo various phase transformations in response to heating or pressure treatment, usually forming hexagonal α-Fe2O3, which is the most thermodynamically stable Fe2O3 polymorph under ambient conditions. Here, from synchrotron X-ray diffraction experiments, we report the formation of a new iron(III) oxide polymorph that we have termed ζ-Fe2O3 and which evolved during pressure treatment of cubic β-Fe2O3 ( space group) at pressures above 30 GPa. Importantly, ζ-Fe2O3 is maintained after pressure release and represents the first monoclinic Fe2O3 polymorph (I2/a space group) that is stable at atmospheric pressure and room temperature. ζ-Fe2O3 behaves as an antiferromagnet with a Néel transition temperature of ~69 K. The complex mechanism of pressure-induced transformation of β-Fe2O3, involving also the formation of Rh2O3-II-type Fe2O3 and post-perovskite-Fe2O3 structure, is suggested and discussed with respect to a bimodal size distribution of precursor nanoparticles.

  18. Characteristics of iron(III) uptake by isolated fragments of rat small intestine in the presence of the hydroxypyrones, maltol and ethyl maltol.

    PubMed

    Levey, J A; Barrand, M A; Callingham, B A; Hider, R C

    1988-05-15

    Accumulation of radioactive iron (59Fe) into isolated fragments of rat small intestine in the presence of two hydroxypyrones, maltol and ethyl maltol, was compared with that in the presence of another chelator of iron(III), nitrilotriacetic acid (NTA). The characteristics of uptake were similar with all three ligands. Between 10(-6) and 10(-4) M, iron uptake showed saturable kinetics. The uptake was partially inhibited by metabolic inhibitors. Above 10(-4) M a non-saturable uptake, unaffected by metabolic inhibitors became evident in the presence of the pyrones. The distribution of 59Fe after uptake was determined by gel filtration. At low iron concentrations (10(-6) M), 35-40% of absorbed iron was associated with proteins of molecular weights similar to those of ferritin and transferrin. At high concentrations (10(-3) M), the majority of 59Fe was found in a low molecular weight fraction. At each concentration, a small amount of 59Fe was bound to a membrane fraction. 5% Polyethylene glycol, which reduces glycocalyx viscosity enhanced uptake at low iron concentrations (10(-6) M) but did not affect the non-saturable diffusion seen at higher concentrations (10(-3) M). The iron(II) chelator, bathophenanthroline sulphonate (10(-3) M), decreased uptake at low iron concentrations but did not affect the non-saturable uptake. It is suggested that conversion of iron(III) to iron(II) may take place at the mucosal cell surface before uptake via the saturable system. Apparent Km values for iron uptake via the saturable system were higher in the presence of maltol and ethyl maltol than in the presence of NTA, presumably since the iron binds more avidly to the hydroxypyrones and so is less readily donated. Excess ligand, either pyrone or NTA, reduced the rate at which 59Fe was donated to the uptake system. The Vmax value for uptake from the pyrones was greater than from NTA. It is concluded that maltol, ethyl maltol and NTA can hold iron(III) in solution and donate it to an

  19. Studies of Wettability of Medical PVC by Remote Nitrogen Plasma

    NASA Astrophysics Data System (ADS)

    Li, Ru; Chen, Jierong

    2006-05-01

    The effects of remote nitrogen plasma and nitrogen plasma on medical PVC's surface modification are studied. The surface properties are characterized by the contact angle measurement, X-ray photoelectron spectroscopy and scanning electron microscopy. Results show that the remote nitrogen plasma treatments modify the PVC surface in both morphology and composition and the treatment by the remote nitrogen plasma in PVC surface modification is more effective than that by the nitrogen plasma. Remote nitrogen plasma can modify the surface more uniformly. After the PVC surface is treated for 2 min by remote nitrogen plasma, the [w(O)+ w(N)]/w(C)] value increases from 0.13 to 0.51 and the water contact angle decreases from 89o to 18o.

  20. 42. VIEW EAST OF PLASTIC STACK (PROBABLY PVC) WHICH VENTED ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    42. VIEW EAST OF PLASTIC STACK (PROBABLY PVC) WHICH VENTED FUMES FROM THE DIPPING OPERATIONS IN BUILDING 49A; BUILDING 49 IS AT THE LEFT OF THE PHOTOGRAPH - Scovill Brass Works, 59 Mill Street, Waterbury, New Haven County, CT

  1. Reactivity of tris(acetylacetonato) iron(III) with tridentate [ONO] donor Schiff base as an access to newer mixed-ligand iron(III) complexes

    NASA Astrophysics Data System (ADS)

    Bhattacharjee, Chira R.; Goswami, Pankaj; Pramanik, Harun A. R.; Paul, Pradip C.; Mondal, Paritosh

    2011-05-01

    Two new mixed-ligand iron(III) complexes, [Fe(L n)(acac)(C 2H 5OH)] incorporating coordinated ethanol from the reaction solvent were accessed from the reaction of [Fe(acac) 3] with [ONO] donor dibasic tridentate unsymmetrical Schiff base ligands derived from condensation of 2-hydroxy-1-napthaldehyde with 2-aminophenol (H 2L 1) or 2-aminobenzoic acid (H 2L 2). The thermal study (TGA-DTA) provided evidence for weakly bound ethanol which is readily substituted by neutral N-donor molecule imidazole, benzimidazole or pyridine to produce an array of newer complexes, [Fe(L n)(acac)X] ( n = 1, 2; X = Im, Bim, Py). The compounds were characterized by elemental analyses, FT-IR, UV-vis, solution electrical conductivity, FAB mass, 1H and 13C NMR spectroscopy. Room temperature magnetic susceptibility measurements ( μeff ˜ 5.8 B.M.) are consistent with spin-free octahedral iron(III) complexes. Cyclic voltammetry of ethanol complexes revealed a quasi-reversible one electron redox response (Δ Ep > 100 mV) for the Fe(III)/Fe(II) couple. Low half wave redox potential ( E1/2) values suggested easy redox susceptibility. The ground state geometries of the ethanol and imidazole complexes have been ascertained to be distorted octahedral by density functional theory using DMol3 program at BLYP/DNP level.

  2. Structure and performance of ZnO/PVC nanocomposites

    NASA Astrophysics Data System (ADS)

    Elashmawi, I. S.; Hakeem, N. A.; Marei, L. K.; Hanna, F. F.

    2010-10-01

    ZnO/PVC nanocomposites films have been prepared by the solvent casting method and investigated by various techniques. All results show good dispersion of ZnO nanoparticles in the polymeric matrix. XRD revealed that pure PVC films are partially crystalline with hallow peak but ZnO nanoparticles have wurtzite structure and the nanocomposite films were almost the same as those of ZnO with decrease in the degree of crystallization, causing increase in the amorphous region. FT-IR presented the same spectra for nanocomposites in the wavenumber range 700-3100 cm -1, weak band located at 500-700 cm -1,which can be attributed to stretching of ZnO bond and an increase of the bending band of OH at 1631 cm -1 was observed. The surface of the films was analyzed by SEM, which becomes rough with some small aggregates compared with pure PVC with good distribution in the entire surface region with bright spots. TEM revealed a regular crystalline lattice superimposed on an amorphous background due to carbon support and PVC matrix and the structure of these particles is hexagonal. In addition, the nanocomposites films have higher glass transition temperature, specific heat and thermal stability relative to those of pure PVC because of strong interaction among ZnO nanoparticles and PVC.

  3. Hoechst and Wacker plan joint venture in PVC

    SciTech Connect

    Young, I.

    1992-12-02

    Restructuring of Europe's petrochemical industry has taken a further step with the announcement that Hoechst (Frankfurt) and Wacker Chemie (Munich) are planning a joint venture in polyvinyl chloride (PVC). The venture would include production, R D, sales and marketing, plus both companies' PVC recycling activities. However, their vinyl chloride monomer (VCM) plants, and Hoechst's Kalle PVC film business, have been left out. Erich Schnitzler, head of Hoechst's PVC business unit, does not anticipate problems with the European Community's competition directorate. We are both among the middle-sized European PVC producers, and together we would have a 9%-10% market share. Our joint venture would not limit competition. Both partners are hoping for approval from Brussels in first-quarter 1993. Hoechst has 255,000 m.t./year of PVC capacity at Gendorfand Knapsack, while Wacker has 365,000 m.t./year at Burghausen and Cologne. All the units, except Wacker's Cologne plant, are back integrated to VCM. The joint venture would buy VCM from the two parent companies and on the merchant market.

  4. Adsorption Characteristics of Different Adsorbents and Iron(III) Salt for Removing As(V) from Water

    PubMed Central

    Ćurko, Josip; Matošić, Marin; Crnek, Vlado; Stulić, Višnja

    2016-01-01

    Summary The aim of this study is to determine the adsorption performance of three types of adsorbents for removal of As(V) from water: Bayoxide® E33 (granular iron(III) oxide), Titansorb® (granular titanium oxide) and a suspension of precipitated iron(III) hydroxide. Results of As(V) adsorption stoichiometry of two commercial adsorbents and precipitated iron(III) hydroxide in tap and demineralized water were fitted to Freundlich and Langmuir adsorption isotherm equations, from which adsorption constants and adsorption capacity were calculated. The separation factor RL for the three adsorbents ranged from 0.04 to 0.61, indicating effective adsorption. Precipitated iron(III) hydroxide had the greatest, while Titansorb had the lowest capacity to adsorb As(V). Comparison of adsorption from tap or demineralized water showed that Bayoxide and precipitated iron(III) hydroxide had higher adsorption capacity in demineralized water, whereas Titansorb showed a slightly higher capacity in tap water. These results provide mechanistic insights into how commonly used adsorbents remove As(V) from water. PMID:27904416

  5. Benzyl and Methyl Fatty Hydroxamic Acids Based on Palm Kernel Oil as Chelating Agent for Liquid-Liquid Iron(III) Extraction

    PubMed Central

    Haron, Md Jelas; Jahangirian, Hossein; Silong, Sidik; Yusof, Nor Azah; Kassim, Anuar; Rafiee-Moghaddam, Roshanak; Mahdavi, Behnam; Peyda, Mazyar; Abdollahi, Yadollah; Amin, Jamileh

    2012-01-01

    Liquid-liquid iron(III) extraction was investigated using benzyl fatty hydroxamic acids (BFHAs) and methyl fatty hydroxamic acids (MFHAs) as chelating agents through the formation of iron(III) methyl fatty hydroxamate (Fe-MFHs) or iron(III) benzyl fatty hydroxamate (Fe-BFHs) in the organic phase. The results obtained under optimized conditions, showed that the chelating agents in hexane extract iron(III) at pH 1.9 were realized effectively with a high percentage of extraction (97.2% and 98.1% for MFHAs and BFHAs, respectively). The presence of a large amount of Mg(II), Ni(II), Al(III), Mn(II) and Co(II) ions did affect the iron(III) extraction. Finally stripping studies for recovering iron(III) from organic phase (Fe-MFHs or Fe-BFHs dissolved in hexane) were carried out at various concentrations of HCl, HNO3 and H2SO4. The results showed that the desired acid for recovery of iron(III) was 5 M HCl and quantitative recovery of iron(III) was achieved from Fe(III)-MFHs and Fe(III)-BFHs solutions in hexane containing 5 mg/L of Fe(III). PMID:22408444

  6. Easy to form expanded PVC cuts protective tray costs 50%

    SciTech Connect

    Vosh, L.

    1982-03-01

    Oak Mitsui Corporation in Hoosick Falls, NY produces copper foil for laminations used to make printed circuit boards for the electronics industry. The electro-deposited foil, before lamination, is further processed in a plating system with a series of 3' deep PVC tanks that contain solutions of acid copper, acid chromate and an alkaline metal complex at elevated temperatures. Each of the tanks rests on a plastic tray with a turned down edge to protect the adjoining steel frames and equipment from spills and splashes of the corrosive fluids. The protective trays are 5 to 6' long and 3 to 6' wide and have a 2'' high vertical lip. They were made of solid PVC plastic and a considerable amount of time and labor was required to form the plastic to the required configuration, and to cut the various openings for the framework and for the pipelines. In 1980, the plant decided to investigate a recently introduced rigid plastic that has been used extensively for industrial and commercial applications where light weight and workability are needed such as computer and peripheral housings, cabinets and aircraft and automotive trim. The material is a continuously extrudecd PVC sheet that is moderately foamed to create a high density, homogeneous cell core structure with a smooth matte surface on both sides. The expanded PVC has the same resistance to corrosive chemicals as solid PVC, but is one-half the weight, has lower thermal conductivity, and superior mechanical strength for better resistance to shock and and impact. The overall cost for the protective trays made from the expanded PVC is about half the cost of the trays that had been used. The material has a lower initial cost than solid PVC or other formable plastics with equivalent corrosion resistance.

  7. Different Arsenate and Phosphate Incorporation Effects on the Nucleation and Growth of Iron(III) (Hydr)oxides on Quartz

    SciTech Connect

    Neil, Chelsea W.; Lee, Byeongdu; Jun, Young-Shin

    2014-10-21

    Iron(III) (hydr)oxides play an important role in the geochemical cycling of contaminants in natural and engineered aquatic systems. The ability of iron(III) (hydr)oxides to immobilize contaminants can be related to whether the precipitates form heterogeneously (e.g., at mineral surfaces) or homogeneously in solution. Utilizing grazing incidence small-angle X-ray scattering (GISAXS), we studied heterogeneous iron(III) (hydr)oxide nucleation and growth on quartz substrates for systems containing arsenate and phosphate anions. For the iron(III) only system, the radius of gyration ( R g ) of heterogeneously formed precipitates grew from 1.5 to 2.5 ( ± 1.0) nm within 1 h. For the system containing 10-5 M arsenate, R g grew from 3.6 to 6.1 ( ± 0.5) nm, and for the system containing 10-5 M phosphate, R g grew from 2.0 to 4.0 ( ± 0.2) nm. While the systems containing these oxyanions had more growth, the system containing only iron(III) had the most nucleation events on substrates. Ex situ analyses of homogeneously and heterogeneously formed precipitates indicated that precipitates in the arsenate system had the highest water content and that oxyanions may bridge iron(III) hydroxide polymeric embryos to form a structure similar to ferric arsenate or ferric phosphate. These new fi ndings are important because di ff erences in nucleation and growth rates and particle sizes will impact the number of available reactive sites and the reactivity of newly formed particles toward aqueous contaminants.

  8. Stabilizing effects of estertins mercaptide (methyl acrylate) for PVC degradation

    NASA Astrophysics Data System (ADS)

    Zhang, S. H.; Liu, T. M.; Li, J. L.; Wang, C. R.; Li, C.; Wang, Z. Q.

    2016-07-01

    The thermal and UV light (ultraviolet light) stability of PVC films with estertins mercaptide (methyl acrylate), methyltins mercaptide and the compound consisted of estertins mercaptide (methyl acrylate) and hydrotalcite (2:2.5) were investigated by ageing in a circulation oven at 190 °C and irradiating with 72W UV light for 96h, respectively, and then the yellowness and transmission rate were tested by Color Quest XE. Hydrotalcite was proved to have good synergies with estertins mercaptide (methyl acrylate) on improving the thermal stability and UV light stability. The retarding effects of the heat stabilizers to PVC degradation were tested by TGA from 50°C to 600°C. The results show that temperature of HCl evolution from PVC film was improved obviously by compounding with estertins mercaptide(methyl acrylate) and hydrotalcite and estertins mercaptide(methyl acrylate) was found to have a better long term stability. Sn4+ consistence of water and seawater in which films before and after UV light irradiation were soaked for 60 days was analyzed by ICP; the results indicate that the Sn4+ consistence from the films with estertins mercaptide(methyl acrylate) as thermal stabilizer was lower than that from the film with methyltins mercaptide. The crosslink moderately by UV irradiation for PVC films can hold back the dissolution of organotin heat stabilizers from PVC products into water and seawater.

  9. Recycling of PVC Waste via Environmental Friendly Vapor Treatment

    NASA Astrophysics Data System (ADS)

    Cui, Xin; Jin, Fangming; Zhang, Guangyi; Duan, Xiaokun

    2010-11-01

    This paper focused on the dechlorination of polyvinyl chloride (PVC), a plastic which is widely used in the human life and thereby is leading to serious "white pollution", via vapor treatment process to recycle PVC wastes. In the process, HCl emitted was captured into water solution to avoid hazardous gas pollution and corruption, and remaining polymers free of chlorine could be thermally degraded for further energy recovery. Optimal conditions for the dechlorination of PVC using vapor treatment was investigated, and economic feasibility of this method was also analyzed based on the experimental data. The results showed that the efficiency of dechlorination increased as the temperature increased from 200° C to 250° C, and the rate of dechlorination up to 100% was obtained at the temperature near 250° C. Meanwhile, about 12% of total organic carbon was detected in water solution, which indicated that PVC was slightly degraded in this process. The main products in solution were identified to be acetone, benzene and toluene. In addition, the effects of alkali catalysis on dechlorination were also studied in this paper, and it showed that alkali could not improve the efficiency of the dechlorination of PVC.

  10. Solubility and durability of cardanol derived plasticizers for soft PVC

    NASA Astrophysics Data System (ADS)

    Greco, Antonio; Ferrari, Francesca; Velardi, Rosario; Frigione, Mariaenrica; Maffezzoli, Alfonso

    2015-12-01

    This work is aimed to study the suitability of cardanol derivatives as primary plasticizer for PVC. The innovative plasticizer is obtained by chemical modification of cardanol, a natural, renewable resource, obtained as a by-product of the cashew nut shell industry. Cardanol derived plasticizers (CDP) were prepared by following various procedures, that allow obtaining different degrees of conversion of cardanol. Rheological and ageing tests were made on soft PVC produced by the addition of CDP;results obtained were compared to soft PVC attained by the use of di-ethyl-hexyl-phthalate (DEHP) and other natural derived plasticizers already used in PVC industry (epoxidated soybean oil, ESBO, and acetic acid ester, AAE).A high dependence on the degree of conversion was found: CDP with a good degree of conversion have similar gelation temperature and diffusion coefficient compared to DEHP based plastisols. Otherwise,CDP with a low degree of conversionshow a higher diffusion coefficient, index of a fast migration of the plasticizer from soft PVC.

  11. Properties of rigid films made of PVC nanocomposites

    NASA Astrophysics Data System (ADS)

    Obloj-Muzaj, Maria; Abramowicz, Agnieszka; Kumosinski, Marcin; Zielecka, Maria; Kozakiewicz, Janusz; Gorska, Agnieszka

    2016-05-01

    PVC nanocomposites containing 0.5 wt. %/VCM of either nanosilica or hybrid core/shell type nanofiller were produced in-situ in suspension polymerisation and rigid films were prepared. The composites obtained were applied in the blends for rigid films. The properties of them were checked and showed advantageous differences in tear resistance and tensile impact properties. It appeared the composites properties let reduce the amount of impact modifiers in the blends at least 40 %. The PVC/SiO2 composite shows the best properties. Even for the blend containing 0.7 part of standard amount of impact modifier (suitable for this formulation) all the properties (except tensile impact strength crosswise) are significantly better than those of PVC blend with full amount of impact modifier.

  12. Improvement of PVC floor tiles by gamma radiation

    NASA Astrophysics Data System (ADS)

    du Plessis, T. A.; Badenhorst, F.

    Gamma radiation presents a unique method of transforming highly plasticized PVC floor tiles, manufactured at high speed through injection moulding, into a high quality floor covering at a cost at least 30% less than similarly rated rubber tiles. A specially formulated PVC compound was developed in collaboration with a leading manufacturer of floor tiles. These tiles are gamma crosslinked in its shipping cartons to form a dimensionally stable product which is highly fire resistant and inert to most chemicals and solvents. The crosslinked tiles are more flexible than the highly filled conventional PVC floor tiles, scratch resistant and have a longer lifespan and increased colour fastness. These tiles are also less expensive to install than conventional rubber tiles.

  13. Strain rate dependence in plasticized and un-plasticized PVC

    NASA Astrophysics Data System (ADS)

    Kendall, M. J.; Siviour, C. R.

    2012-08-01

    An experimental and analytical investigation has been made into the mechanical behaviour of two poly (vinyl chloride) (PVC) polymers - an un-plasticized PVC and a diisononyl phthalate (DINP)-plasticized PVC. Measurements of the compressive stress-strain behaviour of the PVCs at strain rates ranging from 10-3 to 103s-1 and temperatures from - 60 to 100∘C are presented. Dynamic Mechanical Analysis was also performed in order to understand the material transitions observed in compression testing as the strain rate is increased. This investigation develops a better understanding of the interplay between the temperature dependence and rate dependence of polymers, with a focus on locating the temperature and rate-dependent material transitions that occur during high rate testing.

  14. Immittance Responses of Composite PVC Based Polymer Electrolytes

    NASA Astrophysics Data System (ADS)

    Subban, R. H. Y.

    2010-03-01

    Films of PVC containing LiCF3SO3 and SiO2 as filler were prepared by the solution cast technique. The effect of filler concentration on various frequency-dependent immittance responses of PVC-LiCF3SO3-SiO2 complexes were investigated by impedance spectroscopy for temperatures in the range of 173 to 373 K. The immittance responses revealed the films to be ionic conductors while ac conductivity spectra revealed the films to obey the power law feature of σ(ω)∝ωn. This feature became more predominant as temperature increases.

  15. Recommendation to replace PVC disposable shoe cover with alternative materials

    SciTech Connect

    Slaughter, A.E.; Rankin, W.N.

    1992-01-17

    An alternative for disposable shoe covers presently fabricated from PVC (polyvinyl chloride) was investigated to minimize disposal costs. Plans are to incinerate these items for disposal. The exhaust from the incineration of PVC must be processed through a sodium hydroxide scrubber to remove the chlorides. A substantial cost savings ($70OK/yr) would be expected from replacing these supplies with similar items fabricated from a material that contains no chlorides. This report contains evaluations of submitted to the Savannah River Laboratory for testing.

  16. [Safety during the thermal disposal of medical waste containing PVC].

    PubMed

    Soldatenko, N A; Karmanov, V V; Vaisman, Ya I; Samutin, N M

    2013-01-01

    In the article the issues of environmental, sanitary and hygienic safety of medical waste management are considered. Recently, for the treatment of certain types of medical waste thermal methods using small plants not equipped with a proper flue gas cleaning system are widely used. In this article the potential danger of supertoxicants generation when applying thermal methods of neutralization of medical waste that contains polyvinyl chloride (PVC) is justified by thermogravimetric and mass spectrometric studies. This research shows the necessity of introducing technologies of separate collection of PVC medical waste and its' thermal recycling in compliance with special requirements.

  17. Physical Morphology and Quantitative Characterization of Chemical Changes of Weathered PVC/Pine Composites

    DTIC Science & Technology

    2009-12-22

    polyvinyl chloride (PVC) based wood plastic composites (WPC), with a focus on the color and structure that is attributed to the material composition. It is...Keywords Color change Carbonyl concentration Weathering Wood plastic composites Introduction Polyvinyl chloride (PVC) is the most commonly used...distribution unlimited 13. SUPPLEMENTARY NOTES 14. ABSTRACT This study investigated weathering effects on polyvinyl chloride (PVC) based wood

  18. Predicting the Migration Rate of Dialkyl Organotins from PVC Pipe into Water

    EPA Science Inventory

    Organotins (OTs) are additives widely used as thermal and light stabilizers in polyvinyl chloride (PVC) plastics. OTs can leach into water flowing through PVC pipes. This work examines the leaching rates of two neurotoxic OTs, dimethyl tin (DMT) and dibutyl tin (DBT), from PVC pi...

  19. Formation and fluidity measurement of supported lipid bilayer on polyvinyl chloride membrane

    NASA Astrophysics Data System (ADS)

    Kobayashi, Takuji; Kono, Akiteru; Futagawa, Masato; Sawada, Kazuaki; Tero, Ryugo

    2014-02-01

    We prepared an artificial lipid bilayer on a plasticized poly(vinyl chloride) (PVC) membrane on a Si3N4 layer deposited on a Si wafer. We optimized the experimental condition for the fabrication of the PVC membrane, and obtained a PVC membrane with a flat and uniform surface on the scale of several hundreds of micrometer suitable for a substrate for supported lipid bilayers (SLBs). The SLB of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) was formed on the PVC membrane by the vesicle fusion method. The observation with a conventional epi-fluorescence microscope and a confocal laser scanning microscope gave geometrically uniform images of the SLB on the PVC membrane. The fluidity and the mobile fraction of the SLB was evaluated by the fluorescence recovery after photobleaching method, and compared with that on a thermally oxidized SiO2/Si substrate. The SLB on the PVC membrane contained immobile fraction ˜30%, but the diffusion in the mobile fraction was two times faster than that in the SLB on SiO2/Si, which had little immobile fraction.

  20. Iron(III) complexation by Vanchrobactin, a siderophore of the bacterial fish pathogen Vibrio anguillarum.

    PubMed

    Iglesias, Emilia; Brandariz, Isabel; Jiménez, Carlos; Soengas, Raquel G

    2011-05-01

    The bacterial fish pathogen Vibrio anguillarum serotype O2 strain RV22 produces the mono catecholate siderophore Vanchrobactin (Vb) under conditions of iron deficiency. Vb contains two potential bidentate coordination sites: catecholate and salicylate groups. The iron(III) coordination properties of Vb is investigated in aqueous solutions using spectrophotometric and potentiometric methods. The stepwise equilibrium constants (log K) for successive addition of Vb dianion to a ferric ion are 19.9; 13.3, and 9.5, respectively, for an overall association constant of 42.7. Based on the previous results, we estimated the equilibrium concentration of free iron(III) under physiological conditions for pH 7.4 solution containing 10(-6) M total iron and 10(-5) M total Vb as pFe = 20 (=-log[Fe(3+)]). The Vb model compounds catechol (Cat) and 2,4-dihydroxy-N-(2-hydroxyethyl)benzamide (Dhb) have also been examined, and the obtained results show that the interaction of the whole system of Vb that contains the ferric-chelating groups of both Dhb and Cat, is synergically greater than the separate parts; i.e. Vb is the best chelating agent either in acid or basic media. In summary, bacteria employing Vb-mediated iron transport thus are able to compete effectively for iron with other microorganisms within which they live.

  1. Salicylate Detection by Complexation with Iron(III) and Optical Absorbance Spectroscopy: An Undergraduate Quantitative Analysis Experiment

    ERIC Educational Resources Information Center

    Mitchell-Koch, Jeremy T.; Reid, Kendra R.; Meyerhoff, Mark E.

    2008-01-01

    An experiment for the undergraduate quantitative analysis laboratory involving applications of visible spectrophotometry is described. Salicylate, a component found in several medications, as well as the active by-product of aspirin decomposition, is quantified. The addition of excess iron(III) to a solution of salicylate generates a deeply…

  2. Influence of Ionic Liquids on an Iron(III) Catalyzed Three-Component Coupling/Hydroarylation/Dehydrogenation Tandem Reaction.

    PubMed

    Muntzeck, Maren; Wilhelm, René

    2016-06-01

    A three-component oxidative dehydrogenation tandem reaction via the coupling and hydroarylation of benzaldehyde, aniline and phenylacetylene to a quinoline derivate was catalyzed by an iron-containing ionic liquid. The reaction was air mediated and could be performed under neat conditions. The iron(III) of the ionic liquid was the oxidizing species.

  3. Influence of Ionic Liquids on an Iron(III) Catalyzed Three-Component Coupling/Hydroarylation/Dehydrogenation Tandem Reaction

    PubMed Central

    Muntzeck, Maren; Wilhelm, René

    2016-01-01

    A three-component oxidative dehydrogenation tandem reaction via the coupling and hydroarylation of benzaldehyde, aniline and phenylacetylene to a quinoline derivate was catalyzed by an iron-containing ionic liquid. The reaction was air mediated and could be performed under neat conditions. The iron(III) of the ionic liquid was the oxidizing species. PMID:27258264

  4. Properties of irradiated PVC plasticized with non-endocrine disruptor

    NASA Astrophysics Data System (ADS)

    Hutzler, Beatriz W.; Machado, Luci D. B.; Lugão, Ademar B.; Villavicencio, Anna.-Lucia C. H.

    2000-03-01

    Polyvinylchloride (PVC) is under heavy attack from environmentalist groups due to the use of plasticizers and its recycling difficulties. Chloro-organics and phtalates are considered now as ubiquitous global contaminants due to their potential as weak endocrine disruptor and huge consumption. In order to make PVC acceptable for the irradiation processing industry in the long term, non-toxic plasticizers should be used. PVC was added with dioctyl phtalate (DOP) and epoxy soybean oil (ESO) and irradiated up to 50 kGy. Mechanical properties, optical properties and viscosity were measured and compared. The elongation and mechanical strength were under the usual range and they didn't show any significant change in the studied range of irradiation dose. All the samples showed a weak yellowing effect after irradiation and the molecular weight measured by viscosimetry showed only negligible changes. In conclusion, DOP and ESO were shown to be effective in stabilizing the radiolytic abstraction of HCl from PVC. Both plasticizers imparted good color stability and overall properties to the products.

  5. Emission of phthalates from PVC and other materials.

    PubMed

    Afshari, A; Gunnarsen, L; Clausen, P A; Hansen, V

    2004-04-01

    The main objective of this study was to generate quantitative and qualitative emission data on phthalates from different materials. To achieve this the existing (Chamber for Laboratory Investigations of Materials, Pollution and Air Quality) Climpaq-based procedure for simplified measurements of emissions of plasticizer from PVC and other plasticized materials was modified. It was applied to a range of products. Some of them were suspected of contributing to the indoor concentration of plasticizers. The emissions from PVC flooring, polyolefine flooring, a refrigerator list, two electric cables, PVC skirting and floor wax were studied in separate Climpaqs. The emission from the PVC flooring in the Climpaq was compared with results from the ultra-small chamber Field and Laboratory Emission Cell (FLEC). Sampling and analysis methods were optimized to measure plasticizers. Samples were taken in exhaust air from the chambers after 6, 35, 62, 105, and 150 days from the start of the experiment. PVC flooring was tested for an additional 100 days. Polyolefine covered with wax resulted in an air concentration of 22 microg/m3 of dibutylphthalate (DBP), which is two orders of magnitude larger than any other materials, but did not emit di(2-ethylhexyl)phthalate (DEHP). The other materials resulted in max concentration of approximately 1 microg/m3 of DEHP and low emissions of DBP. The concentration of DEHP in each chamber increased slowly to a rather stable level which was reached after 150 days. DBP concentrations in the chambers with PVC skirting, PVC flooring, polyolefine and floor wax reached their quasi-static equilibrium after 60 days. The modified method did not create sufficient data for the calculation of emission rates. Adsorption of emission on chamber surfaces made it impossible to use the first part of the experiment for emission rate calculation. When the concentration had stabilized, it was found to be almost identical and independent of chamber and ventilation

  6. [Research on enhanced photocatalytic degradation of medical PVC by plasma-initiated free radicals].

    PubMed

    Li, Xiao-jing; Qiao, Guan-jun; Chen, Jie-rong

    2007-05-01

    Effects of plasma-initiated free radicals on photocatalytic degradation of medical PVC with anatase TiO2 were studied. Surface properties of PVC were characterized by the contact angle, surface tension, X-ray photoelectron spectroscopy (XPS) and electron spin resonance (ESR). The results indicate that the surface free energy and wettability of plasma-treated PVC increase greatly. The contact angles of distilled water, glycerin and dihydroxyethylsulfide for the plasma-treated PVC decrease. ESR reveals radicals on the surface of the plasma-treated PVC film nearly increase ten times. Moreover, the photodegradation of the PVC-TiO2 was compared with that of plasma-treated PVC-TiO2 through performing weight loss monitoring, scanning electron microscopic (SEM) analysis. Weight-loss rate of the plasma-treated PVC-TiO2 increases 27.4% in comparison with that of PVC-TiO2 under UV irradiation for 60 hours. SEM of the plasma-treated PVC-TiO2 film shows a lot of crack on the surface after photodegradation. Plasma treatments aggravate the photocatalytic degradation of medical PVC.

  7. N-butylamine functionalized graphene oxide for detection of iron(III) by photoluminescence quenching.

    PubMed

    Gholami, Javad; Manteghian, Mehrdad; Badiei, Alireza; Ueda, Hiroshi; Javanbakht, Mehran

    2016-02-01

    An N-butylamine functionalized graphene oxide nanolayer was synthesized and characterized by ultraviolet (UV)-visible spectrometry, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and transmission electron microscopy. Detection of iron(III) based on photoluminescence spectroscopy was investigated. The N-butylamine functionalized graphene oxide was shown to specifically interact with iron (III), compared with other cationic trace elements including potassium (I), sodium (I), calcium (II), chromium (III), zinc (II), cobalt (II), copper (II), magnesium (II), manganese (II), and molybdenum (VI). The quenching effect of iron (III) on the luminescence emission of N-butylamine functionalized graphene oxide layer was used to detect iron (III). The limit of detection (2.8 × 10(-6)  M) and limit of quantitation (2.9 × 10(-5)  M) were obtained under optimal conditions.

  8. Repeptization by dissolution in a colloidal system of iron(III) pyrophosphate.

    PubMed

    van Leeuwen, Y Mikal; Velikov, Krassimir P; Kegel, Willem K

    2012-12-04

    Repeptization (redispersion) from an aggregated state is usually only possible in charge-stabilized colloidal systems if the system is either coagulated in the secondary minimum of the interaction potential or if the system cannot settle completely into the primary minimum. In this work, we analyze the zeta potential, conductivity, and long-term stability of colloidal systems of iron(III) pyrophosphate and surprisingly find that the system seems to defy conventional wisdom as it can be repeptized from its coagulated state regardless of aging time and background ions. Moreover, after having been stored for up to a month in 2 M NaCl, dialysis of iron pyrophosphate will yield a colloidal dispersion that is actually stable for a longer period of time than a fresh system with background electrolyte removed.

  9. Bis(cyano) Iron(III) Porphyrinates: What Is the Ground State?

    PubMed

    Li, Jianfeng; Noll, Bruce C; Schulz, Charles E; Scheidt, W Robert

    2015-07-06

    The synthesis of six new bis(cyano) iron(III) porphyrinate derivatives is reported. The anionic porphyrin complexes utilized tetraphenylporphyrin, tetramesitylporphyrin, and tetratolylporphyrin as the porphyrin ligand. The potassium salts of Kryptofix-222 and 18-C-6 were used as the cations. These complexes have been characterized by X-ray structure analysis, solid-state Mössbauer spectroscopy, and EPR spectroscopy, both in frozen CH2Cl2 solution and in the microcrystalline state. These data show that these anionic complexes can exist in either the (dxz,dyz)(4)(dxy)(1) or the (dxy)(2)(dxz,dyz)(3) electronic configuration and some can clearly readily interconvert. This is a reflection that these two states can be very close in energy. In addition to the effects of varying the porphyrin ligand, subtle effects of the cyanide ligand environment in the solid state and in solution are sufficient to shift the balance between the two electronic states.

  10. Inhibition of lipid peroxidation promoted by iron(III) and ascorbate.

    PubMed

    Beach, D C; Giroux, E

    1992-09-01

    Peroxidation of rat liver microsomes and of phospholipid isolated from them was studied using iron(III) and ascorbate initiation. One-half equivalent of citrate per iron equivalent maintained solubility of the metal ion at neutral pH. Several metal chelators, including additional citrate, blocked peroxidation, but catalase did not. These characteristics are consistent with those reported by others (D. M. Miller and S. D. Aust (1989) Arch. Biochem. Biophys. 271, 113-119). Several antioxidants, principally tocopherol analogues and nitroxides, and, as well, a nonenzymatic component of "thymol-free" catalase, potently blocked lipid peroxidation, or, equivalently, dioxygen depletion from suspensions of peroxidizing microsomes. Chromanols were the most active antioxidants. No thiol studied had significant antioxidant activity in the test system.

  11. Biotin-conjugated tumour-targeting photocytotoxic iron(III) complexes.

    PubMed

    Saha, Sounik; Majumdar, Ritankar; Hussain, Akhtar; Dighe, Rajan R; Chakravarty, Akhil R

    2013-07-28

    Iron(III) complexes [FeL(B)] (1-4) of a tetradentate phenolate-based ligand (H3L) and biotin-conjugated dipyridophenazine bases (B), viz. 7-aminodipyrido [3,2-a:2',3'-c]-phenazine (dppza in 1), (N-dipyrido[3,2-a:2',3'-c]-phenazino)amidobiotin (dppzNB in 2), dipyrido [3,2-a:2',3'-c]-phenazine-11-carboxylic acid (dppzc in 3) and 2-((2-biotinamido)ethyl) amido-dipyrido[3,2-a:2',3'-c]-phenazine (dppzCB in 4) are prepared, characterized and their interaction with streptavidin and DNA and their photocytotoxicity and cellular uptake in various cells studied. The high-spin iron(III) complexes display Fe(III)/Fe(II) redox couple near -0.7 V versus saturated calomel electrode in dimethyl sulfoxide-0.1 M tetrabutylammonium perchlorate. The complexes show non-specific interaction with DNA as determined from the binding studies. Complexes with appended biotin moiety show similar binding to streptavidin as that of free biotin, suggesting biotin conjugation to dppz does not cause any loss in its binding affinity to streptavidin. The photocytotoxicity of the complexes is tested in HepG2, HeLa and HEK293 cell lines. Complex 2 shows higher photocytotoxicity in HepG2 cells than in HeLa or HEK293, forming reactive oxygen species. This effect is attributed to the presence of overexpressed sodium-dependent multi-vitamin transporters in HepG2 cells. Microscopic studies in HepG2 cells show internalization of the biotin complexes 2 and 4 essentially occurring by receptor-mediated endocytosis, which is similar to that of native biotin and biotin fluorescein isothiocyanate conjugate.

  12. Microporous polyvinyl chloride: novel reactor for PVC/CaCO3 nanocomposites

    NASA Astrophysics Data System (ADS)

    Xiong, Chuanxi; Lu, Shengjun; Wang, Dongyan; Dong, Lijie; Jiang, David D.; Wang, Qinggang

    2005-09-01

    Microporous polyvinyl chloride (PVC) with pore size of 0.2-2 µm has been obtained by the foaming of PVC powders using a solution of 2,2'-azo-bis-iso-butyronitrile in a co-solvent of butanone and cyclohexanone. The PVC/CaCO3 hybrid powders deposited with CaCO3 nanoparticles have been synthesized using the microporous PVC as reactors of CaCO3 nanoparticles, i.e., the reaction of Ca(OH)2 with CO2 occurs inside the pore of microporous PVC. The in situ PVC/CaCO3 nanocomposites have been prepared by melt blending in situ PVC/CaCO3 hybrid powders. The images of SEM and TEM show that the in situ CaCO3 nanoparticles are uniformly dispersed in the PVC matrix and the sizes of the CaCO3 nanoparticles are less than 50 nm. TEM images and XRD patterns for the in situ CaCO3 strongly suggest that pseudo-amorphous crystals and defect-rich crystals are formed. The mechanical properties and DMA data indicate that the in situ PVC/CaCO3 nanocomposites exhibit much higher strength, toughness, modulus and glass temperature than common PVC/CaCO3 nanocomposites. This novel nanotechnology has potential applications in preparation of organic-inorganic hybrid nanocomposites.

  13. The Three-Dimensional Structures of Pseudomonas Aeruginosa PvcA And PvcB, Two Proteins Involved in the Synthesis of 2-Isocyano-6,7-Dihydroxycoumarin

    SciTech Connect

    Drake, E.J.; Gulick, A.M.

    2009-05-12

    The pvcABCD operon of Pseudomonas aeruginosa encodes four proteins (PA2254, PA2255, PA2256, and PA2257) that form a cluster that is responsible for the synthesis of a cyclized isocyano derivative of tyrosine. These proteins, which were identified originally as being responsible for a step in the maturation of the chromophore of the peptide siderophore pyoverdine, have been identified recently as belonging to a family of proteins that produce small organic isonitriles. We report that strains harboring a disruption in the pvcA or pvcB genes are able to grow in iron-depleted conditions and to produce pyoverdine. Additionally, we have determined the three-dimensional crystal structures of PvcA and PvcB. The structure of PvcA demonstrates a novel enzyme architecture that is built upon a Rossmann fold. We have analyzed the sequence conservation of enzymes within this family and identified six conserved motifs. These regions of the protein cluster around a putative active site cavity. The structure of the PvcB protein confirms it is a member of the Fe2+/alpha-ketoglutarate-dependent oxygenase family of enzymes. The active site of PvcB is compared to the structures of other family members and suggests that a conformational change to order several loops will accompany the binding of ligands.

  14. The effects of thermally reversible agents on PVC stability properties

    NASA Astrophysics Data System (ADS)

    Wang, J.; Yao, J.; Xiong, X. H.; Jia, C. X.; Ren, R.; Chen, P.; Liu, X. M.

    2016-07-01

    One kind of thermally reversible cross-linking agents for improving PVC thermally stability was synthesized. The chemical structure and thermally reversible characteristics of cross-linking agents were investigated by FTIR and DSC analysis, respectively. FTIR results confirmed that the cyclopentadienyl barium mercaptides ((CPD-C2H4S)2Ba) were successfully synthesized. DSC results showed it has thermally reversible characteristics and the depolymerization temperature was between 170 °C and 205 °C. The effects of cross-linking reaction time on gel content of Poly(vinyl chloride) compounds was evaluated. The gel content value arrived at 42% after being cross-linked for 25 min at 180 C. The static thermally stability measurement proved that the thermally stability of PVC compounds was improved.

  15. Optimized Quality Factor of Graphene Oxide-Reinforced PVC Nanocomposite

    NASA Astrophysics Data System (ADS)

    Joshi, Girish M.; Deshmukh, Kalim

    2014-04-01

    Graphene oxide (GO)-reinforced polyvinyl chloride (PVC) composite films were prepared by solution blending. The homogeneity of GO dispersion with PVC was confirmed by an optical microscope. Quality factor ( Q-factor) as a function of temperature (40-150 °C) was measured within a broadband frequency range of 50-35 MHz. The controlled GO loading demonstrates a crucial impact on the optimization of the Q-factor, resonance frequency ( f 0) and wide bandwidth. This nanocomposite may be well suited for electronic applications. The further development of GO-reinforced polymer nanocomposites based on an optimized Q-factor may result in a material for electromagnetic frequency radiation shields for radar and communication towers/devices.

  16. Selective flotation of PVC using gelatin and lignin alkali.

    PubMed

    Yenial, Unzile; Kangal, Olgaç; Güney, Ali

    2013-06-01

    Recycling has become one of the most important issues as a result of increasing waste mass in present day. This is especially important for polymer wastes as they are hard to degenerate in nature. Today, most of the practical methods used for the recycling of waste mass, such as hand sorting, gravity separation, etc., cannot be performed successfully owing to close densities of polymers. Froth flotation can be used successfully and economically for this purpose. The main objective of this study was to investigate the effect of plasticizer reagents and the success of froth flotation at plastic recycling. In this study, lignin alkali and gelatin were used as plasticizer reagents. The effect of these reagents was searched with the parameters of pH, concentration, conditioning and flotation time. In the case of post-consumed polyethylene terephthalate and polyvinyl chloride (PVC), 98.9% purity of PVC was obtained at optimum conditions.

  17. Emission of volatile organic compounds (VOCs) from PVC floor coverings.

    PubMed

    Wiglusz, R; Igielska, B; Sitko, E; Nikel, G; Jarnuszkiewicz, I

    1998-01-01

    In this study 29 PVC floor coverings were tested for emission of vinyl chloride (VC) and other volatile organic compounds (VOCs). A study on the effect of higher temperature on emission of VOCs from newly manufactured PVC flooring was also carried out. The study was conducted in climatic chamber, according to Polish Standard PN-89/Z-04021. GC method was used for analyzing of the compounds emitted. VC was not emitted from any of the floorings tested. Other VOCs were emitted in different concentrations. The influence of temperature on emission was conducted at temperatures of 23 degrees C and 35 degrees C from 2 hrs up to 180 days after introduction of materials in the chamber. The increase of temperature caused increase of total volatile organic compounds (TVOC) emission during 24 hrs of experiment. Then the emission was comparable for both temperatures. After 9 days emission of identified and unidentified compounds (TVOC) showed a rapid decay and stayed on very low level during a few months. The study conducted showed that PVC floorings after 10 days of installation in the room should not be source of indoor air contamination.

  18. Electron beam crosslinking of non-lead PVC formulations

    NASA Astrophysics Data System (ADS)

    Castañeda Facio, A.; Benavides, R.; Martínez Pardo, M. E.; Uribe, R.

    2007-11-01

    PVC samples with lead-free and lead-base stabilizer, containing TMPTMA (trimethylolpropane trimethacrylate) as a crosslinker and DOP (2-ethylhexyl phthalate) as a plasticizer, were electron beam treated at different doses (2-200 kGy) and characterized to evaluate crosslinking and other several properties, as a continuation of our previously reported paper, where these PVC formulations, typical for wire and cable applications, underwent gamma irradiation. The PVC was formulated with two different stabilizing systems: Ca/Zn and dibasic lead phthalate for comparison, to use them as jackets for a 22 wire gage (AWG). Small samples of the jacketed wires were irradiated in an industrial Dynamitron electron accelerator for the corresponding doses, along with two dosimetric systems: radiochromic thin film and alanine pellets dosimeters. The maximum dose applied was decided as the crosslinking increased, until the gel content was stable. The dose of 200 kGy was the condition for the highest crosslinking, so most of the wire was irradiated at such dose. Chemical and mechanical evaluations were carried out to the irradiated wire. The results show that 200 kGy was too high dose for the materials, since an important degradation is observed for the Ca/Zn systems. Unfortunately, such dose affects basically to CaZn formulations, which showed much poorer performance than classical lead-containing compositions. The results also indicate that gel content is not the best way of deciding the optimum condition for irradiation.

  19. Prebiotic Polymerization: Oxidative Polymerization of 2,3 Dimercapto-1- Propanol on the Surface of Iron(III) Hydroxide Oxide

    NASA Technical Reports Server (NTRS)

    Weber, Arthur L.

    1995-01-01

    The oxidation of 2,3-dimercapto-1-propanol by ferric ions on the surface of iron(III) hydroxide oxide (Fe(OH)O) yielded polydisulfide oligomers. This polymerization occurred readily at low dithiol concentration under mild aqueous conditions. Polydisulfide polymers up to the 15-mer were synthesized from 1 mM dithiol in 5 ml water reacted with iron(III) hydroxide oxide (20 mg, 160 micromole Fe) for 3 days under anaerobic conditions at 40 C and pH 4. About 91% of the dithiol was converted to short soluble oligomers and 9% to insoluble larger oligomers that were isolated with the FE(OH)O phase. Reactions carried out at the same ratio of dithiol to FE(OH)O but at higher dithiol concentrations gave higher yields of the larger insoluble oligomers. The relationship of these results to prebiotic polymer synthesis is discussed.

  20. Prebiotic polymerization: Oxidative polymerization of 2, 3-dimercapto-1-propanol on the surface of iron(III) hydroxide oxide

    NASA Technical Reports Server (NTRS)

    Weber, Arthur L.

    1995-01-01

    The oxidation of 2, 3-dimercapto-1-propanol by ferric ions on the surface of iron(III) hydroxide oxide (Fe(OH)O) yielded polydisulfide oligomers. This polymerization occurred readily at low dithiol concentration under mild aqueous conditions. Polydisulfide polymers up to the 15-mer were synthesized from 1 mM dithiol in 5 ml water reacted with iron(III) hydroxide oxide (20 mg, 160 micromole Fe) for 3 days under anaerobic conditions at 40 C and pH 4. About 91% of the dithiol was converted to short soluble oligomers and 9% to insoluble larger oligomers that were isolated with the Fe(OH)O phase. Reactions carried out at the same ratio of dithiol to Fe(OH)O but at higher dithiol concentrations gave higher yields of the larger insoluble oligomers. The relationship of these results to prebiotic polymer synthesis is discussed.

  1. Gallium(III) Tetraphenylporphyrinates Containing Hydrosulfide and Thiolate Ligands: Structural Models for Sulfur-Bound Iron(III) Hemes.

    PubMed

    Meininger, Daniel J; Chee-Garza, Max; Arman, Hadi D; Tonzetich, Zachary J

    2016-03-07

    Gallium(III) tetraphenylporphyrinates (TPP) containing anionic sulfur ligands have been prepared and characterized in the solid state and solution. The complexes serve as structural models for iron(III) heme sites containing sulfur coordination that otherwise prove challenging to synthesize due to the propensity for reduction to iron(II). The compounds prepared include the first well-characterized example of a trivalent metalloporphyrinate containing a terminal hydrosulfide ligand, [Ga(SH)(TPP)], as well as [Ga(SEt)(TPP)], [Ga(SPh)(TPP)], and [Ga(SSi(i)Pr3)(TPP)]. The stability of these compounds toward reduction has permitted an investigation of their solid-state structures and electrochemistry. The structural features and reaction chemistry of the complexes in relation to their iron(III) analogs is discussed.

  2. TG/FTIR analysis on co-pyrolysis behavior of PE, PVC and PS.

    PubMed

    Wu, Jingli; Chen, Tianju; Luo, Xitao; Han, Dezhi; Wang, Zhiqi; Wu, Jinhu

    2014-03-01

    The pyrolysis and co-pyrolysis behaviors of polyethylene (PE), polystyrene (PS) and polyvinyl chloride (PVC) under N2 atmosphere were analyzed by Thermal gravimetric/Fourier transform infrared (TG/FTIR). The volatile products were analyzed to investigate the interaction of the plastic blends during the thermal decomposition process. The TGA results showed that the thermal stability increased followed by PVC, PS and PE. The pyrolysis process of PE was enhanced when mixed with PS. However, PS was postponed when mixed with PVC. As for PE and PVC, mutual block was happened when mixed together. The FTIR results showed that the free radical of the decomposition could combine into a stable compound. When PE mixed with PVC or PS, large amount of unsaturated hydrocarbon groups existed in products while the content of alkynes was decreased. The methyl (-CH3) and methylene (-CH2-) bonds were disappeared while PVC mixed with PE.

  3. Nondestructive Quantification of Local Plasticizer Concentration in PVC by (1)H NMR Relaxometry.

    PubMed

    Adams, Alina; Kwamen, Rance; Woldt, Benjamin; Graß, Michael

    2015-12-01

    The properties of plasticized poly(vinyl chloride) (PVC) , one of the most important polymers today, are strongly dictated by the concentration of plasticizer. Yet, it has been impossible to quantify this concentration at different positions inside a PVC product without its destruction because of a lack of suitable analytical methods. Thus, this paper introduces a simple, fast, and efficient way to determine truly nondestructively the concentration of plasticizer in PVC by single-sided nuclear magnetic resonance (NMR). With the help of correlation curves between the concentration of plasticizer inside nonaged PVC samples and the corresponding volume-averaged NMR parameters, single-sided NMR allows the quantification of the local concentration of plasticizer in aged PVC plates at different depths by spatially resolved relaxation measurements. The presented approach represents a fundamental step toward in situ characterization of plasticized PVC.

  4. Plasticizer migration from cross-linked flexible PVC. 1. Effects on tribology

    NASA Astrophysics Data System (ADS)

    Pannico, M.; Persico, P.; Ambrogi, V.; Carfagna, C.

    2010-06-01

    Utilization of soft PVC is restricted by plasticizer migration that can affect material properties, as well as its toxicity. Modifying the chemical structure of PVC is one of the most effective tool to reduce the diffusion of plasticizer. In this work, a soft cross-linked PVC was obtained using a difunctional amine, namely isophoron diamine (IPDA) as the cross-linking agent. The gel content (wt %) was evaluated by weighting the insoluble portion obtained through solvent extraction technique. Thermogravimetric analysis (TGA) revealed that cross-linking reactions promote thermal degradation phenomena in the polymer matrix. Tribological properties of soft uncross-linked, cross-linked and rigid PVC were determined. Soft formulations were held in contact for 32 days with rigid PVC sheets. Plasticizer migration towards the interface causes an increase of dynamic friction compared to that of the reference rigid PVC.

  5. On the initial flaw sizes of uPVC pipe materials

    SciTech Connect

    Kim, H.S. . Dept. of Mechanical Engineering)

    1993-12-20

    It is well known that flaws in unplasticized poly(vinyl chloride) (uPVC) pipes are generated during processing. The flaws include inclusions, gas bubbles, and results from poor fusion between PVC grains and extrusion additives. uPVC pipes are often used for water reticulation, subjected to an alternating pressure superimposed on a mean pressure. uPVC pipe samples have been found to fail in fatigue from a small semicircular flaw on the inside bore of the pipe. In designing uPVC pipes against fatigue failure due to pressure variation, it is essential to determine the initial flaw size. Truss attempted to estimate the lifespan of uPVC pipes and showed that predictions and experimental data are in good agreement.

  6. I-TiO2/PVC film with highly photocatalytic antibacterial activity under visible light.

    PubMed

    Deng, Weihua; Ning, Shangbo; Lin, Qianying; Zhang, Hualei; Zhou, Tanghua; Lin, Huaxiang; Long, Jinlin; Lin, Qun; Wang, Xuxu

    2016-08-01

    Iodine-modified TiO2(I-TiO2) film were coated on medical-grade PVC material by impregnation-deposition method and subsequently characterized by XRD, SEM, TEM, AFM, DRS and XPS. The photocatalytic anti-bacterial activity of I-TiO2/PVC was investigated both by in vitro anti-bacterial experiments and by clinical study. The results revealed that I-TiO2/PVC exhibit excellent photocatalytic antibacterial activity, which can destroy the propagation of the Escherichia coli and cause the deactivation and death of most E. coli bacteria within 30min visible light illumination. Clinical study on animals showed that I-TiO2 coated on PVC decrease the formation of biofilm on PVC surface in the mechanical ventilation. Furthermore, I-TiO2/PVC can effectively reduce inflammation of tracheal tissue of bam suckling pig and prevents the occurrence of VAP.

  7. Extracellular polymeric substances mediate bioleaching/biocorrosion via interfacial processes involving iron(III) ions and acidophilic bacteria.

    PubMed

    Sand, Wolfgang; Gehrke, Tilman

    2006-01-01

    Extracellular polymeric substances seem to play a pivotal role in biocorrosion of metals and bioleaching, biocorrosion of metal sulfides for the winning of precious metals as well as acid rock drainage. For better control of both processes, the structure and function of extracellular polymeric substances of corrosion-causing or leaching bacteria are of crucial importance. Our research focused on the extremophilic bacteria Acidithiobacillus ferrooxidans and Leptospirillum ferrooxidans, because of the "simplicity" and knowledge about the interactions of these bacteria with their substrate/substratum and their environment. For this purpose, the composition of the corresponding extracellular polymeric substances and their functions were analyzed. The extracellular polymeric substances of both species consist mainly of neutral sugars and lipids. The functions of the exopolymers seem to be: (i) to mediate attachment to a (metal) sulfide surface, and (ii) to concentrate iron(III) ions by complexation through uronic acids or other residues at the mineral surface, thus, allowing an oxidative attack on the sulfide. Consequently, dissolution of the metal sulfide is enhanced, which may result in an acceleration of 20- to 100-fold of the bioleaching process over chemical leaching. Experiments were performed to elucidate the importance of the iron(III) ions complexed by extracellular polymeric substances for strain-specific differences in oxidative activity for pyrite. Strains of A. ferrooxidans with a high amount of iron(III) ions in their extracellular polymeric substances possess greater oxidation activity than those with fewer iron(III) ions. These data provide insight into the function of and consequently the advantages that extracellular polymeric substances provide to bacteria. The role of extracellular polymeric substances for attachment under the conditions of a space station and resulting effects like biofouling, biocorrosion, malodorous gases, etc. will be discussed.

  8. Influence of plasticizer content on the transition of electromechanical behavior of PVC gel actuator.

    PubMed

    Ali, Mohammad; Ueki, Takamitsu; Tsurumi, Daijiro; Hirai, Toshihiro

    2011-06-21

    The actuation performance of plasticized poly(vinyl chloride) (PVC) gel actuators in an electric field depends on their chemical composition and electrical and mechanical properties. The influence of plasticizer (dibutyl adipate) content on electromechanical behavior of PVC gels was investigated by impedance spectroscopy and space charge measurement. By plasticizing the PVC, the dielectric constant and space charge density of PVC gel were drastically increased at 1:2 w/w ratio of PVC to plasticizer. To apply the results obtained from the impedance spectroscopy and space charge measurement, electrostatic adhesive forces generated between the PVC gel and the anode were measured. The electrostatic adhesive force at the anode was also dramatically increased at the same plasticizer content. All of the results indicated a transition of electromechanical behavior of PVC gel in the electric field, which was considered to originate from the orientation of polarized plasticizer molecules and dipole rotation of PVC chains. By using the electrostatic adhesive force of PVC gel derived from the electromechanical transition, a new electroactive actuator can be developed for novel applications.

  9. Quality control in the recycling stream of PVC from window frames by hyperspectral imaging

    NASA Astrophysics Data System (ADS)

    Luciani, Valentina; Serranti, Silvia; Bonifazi, Giuseppe; Di Maio, Francesco; Rem, Peter

    2013-05-01

    Polyvinyl chloride (PVC) is one of the most commonly used thermoplastic materials in respect to the worldwide polymer consumption. PVC is mainly used in the building and construction sector, products such as pipes, window frames, cable insulation, floors, coverings, roofing sheets, etc. are realised utilising this material. In recent years, the problem of PVC waste disposal gained increasing importance in the public discussion. The quantity of used PVC items entering the waste stream is gradually increased as progressively greater numbers of PVC products approach to the end of their useful economic lives. The quality of the recycled PVC depends on the characteristics of the recycling process and the quality of the input waste. Not all PVC-containing waste streams have the same economic value. A transparent relation between value and composition is required to decide if the recycling process is cost effective for a particular waste stream. An objective and reliable quality control technique is needed in the recycling industry for the monitoring of both recycled flow streams and final products in the plant. In this work hyperspectral imaging technique in the near infrared (NIR) range (1000-1700 nm) was applied to identify unwanted plastic contaminants and rubber present in PVC coming from windows frame waste in order to assess a quality control procedure during its recycling process. Results showed as PVC, PE and rubber can be identified adopting the NIR-HSI approach.

  10. Carbohydrate-appended tumor targeting iron(III) complexes showing photocytotoxicity in red light.

    PubMed

    Basu, Uttara; Khan, Imran; Hussain, Akhtar; Gole, Bappaditya; Kondaiah, Paturu; Chakravarty, Akhil R

    2014-02-17

    Glucose-appended photocytotoxic iron(III) complexes of a tridentate Schiff base phenolate ligand [Fe(bpyag)(L)](NO3) (1-3), where bpyag is N,N-bis(2-pyridylmethyl)-2-aminoethyl-β-D-glucopyranoside and H2L is 3-(2-hydroxyphenylimino)-1-phenylbutan-1-one (H2phap) in 1, 3-(2-hydroxyphenylimino)-9-anthrylbutan-1-one (H2anap) in 2, and 3-(2-hydroxyphenylimino)-1-pyrenylbutan-1-one (H2pyap) in 3, were synthesized and characterized. The complex [Fe(dpma)(anap)](NO3) (4), having bis-(2-pyridylmethyl)benzylamine (dpma), in which the glucose moiety of bpyag is substituted by a phenyl group, was used as a control, and the complex [Fe(dpma)(anap)](PF6) (4a) was structurally characterized by X-ray crystallography. The structure shows a FeN4O2 core in a distorted octahedral geometry. The high-spin iron(III) complexes with magnetic moment value of ∼5.9 μB showed a low-energy phenolate-to-Fe(III) charge-transfer (CT) absorption band as a shoulder near 500 nm with a tail extending to 700 nm and an irreversible Fe(III)-Fe(II) redox couple near -0.6 V versus saturated calomel electrode. The complexes are avid binders to calf thymus DNA and showed photocleavage of supercoiled pUC19 DNA in red (647 nm) and green (532 nm) light. Complexes 2 and 3 displayed significant photocytotoxicity in red light, with an IC50 value of ∼20 μM in HeLa and HaCaT cells, and no significant toxicity in dark. The cell death is via an apoptotic pathway, by generation of reactive oxygen species. Preferential internalization of the carbohydrate-appended complexes 2 and 3 was evidenced in HeLa cells as compared to the control complex 4. A 5-fold increase in the cellular uptake was observed for the active complexes in HeLa cells. The photophysical properties of the complexes are rationalized from the density functional theory calculations.

  11. Isolation of microorganisms involved in reduction of crystalline iron(III) oxides in natural environments

    PubMed Central

    Hori, Tomoyuki; Aoyagi, Tomo; Itoh, Hideomi; Narihiro, Takashi; Oikawa, Azusa; Suzuki, Kiyofumi; Ogata, Atsushi; Friedrich, Michael W.; Conrad, Ralf; Kamagata, Yoichi

    2015-01-01

    Reduction of crystalline Fe(III) oxides is one of the most important electron sinks for organic compound oxidation in natural environments. Yet the limited number of isolates makes it difficult to understand the physiology and ecological impact of the microorganisms involved. Here, two-stage cultivation was implemented to selectively enrich and isolate crystalline iron(III) oxide reducing microorganisms in soils and sediments. Firstly, iron reducers were enriched and other untargeted eutrophs were depleted by 2-years successive culture on a crystalline ferric iron oxide (i.e., goethite, lepidocrocite, hematite, or magnetite) as electron acceptor. Fifty-eight out of 136 incubation conditions allowed the continued existence of microorganisms as confirmed by PCR amplification. High-throughput Illumina sequencing and clone library analysis based on 16S rRNA genes revealed that the enrichment cultures on each of the ferric iron oxides contained bacteria belonging to the Deltaproteobacteria (mainly Geobacteraceae), followed by Firmicutes and Chloroflexi, which also comprised most of the operational taxonomic units (OTUs) identified. Venn diagrams indicated that the core OTUs enriched with all of the iron oxides were dominant in the Geobacteraceae while each type of iron oxides supplemented selectively enriched specific OTUs in the other phylogenetic groups. Secondly, 38 enrichment cultures including novel microorganisms were transferred to soluble-iron(III) containing media in order to stimulate the proliferation of the enriched iron reducers. Through extinction dilution-culture and single colony isolation, six strains within the Deltaproteobacteria were finally obtained; five strains belonged to the genus Geobacter and one strain to Pelobacter. The 16S rRNA genes of these isolates were 94.8–98.1% identical in sequence to cultured relatives. All the isolates were able to grow on acetate and ferric iron but their physiological characteristics differed considerably in

  12. Nonmigrating Equivalent Substitutes for PVC/DOP Formulations as Shown by a TG Study of PVC with Covalently Bound PEO-PPO Oligomers.

    PubMed

    Navarro, Rodrigo; Gacal, Tülin; Ocakoglu, Melike; García, Carolina; Elvira, Carlos; Gallardo, Alberto; Reinecke, Helmut

    2017-03-01

    Monoamino functionalized ethylenoxide (EO)/propylenoxide oligomers (Jeffamine) are linked chemically to poly(vinyl chloride) (PVC) using trichlorotriazine chemistry in order to prepare nonmigrating internally plasticized materials. The dependence of the plasticizer efficiency on both the number of anchoring points to the chains and the PVC/plasticizer compatibility is investigated using oligomers of different molecular weight and hydrophilic-hydrophobic balance. Hydrophilic oligomers (containing predominantly EO) of molecular weights between 2000 and 5000 g mol(-1) exhibit excellent plasticizer efficiency, nearly identical to di-2-ethylhexylphthalate (DOP) in conventional PVC/DOP mixtures and may therefore be used as nonmigrating equivalents for DOP.

  13. Separation of polyvinyl chloride (PVC) from automobile shredder residue (ASR) by froth flotation with ozonation.

    PubMed

    Reddy, Mallampati Srinivasa; Kurose, Keisuke; Okuda, Tetsuji; Nishijima, Wataru; Okada, Mitsumasa

    2007-08-25

    The purpose of this study is to develop froth flotation to separate polyvinyl chloride (PVC) from automobile shredder residue (ASR) plastic mixtures of variable composition. Some polymers in ASR polymer mixtures have similar density and hydrophobicity with PVC and thus selective flotation of PVC from ASR polymer mixtures cannot be achieved. The present study focused on the surface modification of PVC with ozonation, and then the modified PVC can be separated from other polymers by the following froth flotation. The results of this study indicate that the selective recovery of PVC from real ASR polyethylene tetra pethelate (PET), polymethyl methacrylate (PMMA), polybutyl methacralate (PBMA), ethyl acrylate (EA), polycarbonate (PC) and rubber mixtures can be accomplished in a three-step process involving a gravity separation, ozonation and froth flotation. The rubber was removed from other heavy ASR (PVC, PET, PMMA, PBMA, EA and PC) polymers by froth flotation without mixing. It was found that ozonation process produced the desired difference in contact angle required (from 89.5 to 73.0 degrees ) for separation of PVC from other heavy ASR polymers, whereas the contact angles of other polymers was slightly decreased. The most of the load ASR, i.e. about 72.4% is floated away and 27.6% was settled down. The highest component 96.7% of PVC was recovered in the settled fraction. As a result of this research effort, the surface modification of PVC with ozonation can be efficiently useful to separate the PVC from other similar density ASR mixed polymers.

  14. Occupational hazards in the VC-PVC industry.

    PubMed

    Nicholson, W J; Henneberger, P K; Seidman, H

    1984-01-01

    Overall, the results of the analysis of 12 studies of VC production and polymerization workers demonstrate an enormously elevated risk of liver malignancies, the possibility of a twofold increased risk of brain and central nervous system tumors and perhaps, also, of malignancies of the lymphatic and hematopoietic system. However, the role of other agents cannot be excluded in the etiology of nonhepatic malignancies. Bronchogenic carcinoma does not appear to be increased from exposures to VC monomer, although a relationship to PVC dust was suggested in one study. These conclusions must be considered in light of limited data on workers followed more than 25 years from onset of exposure. Considering the numbers of observed and expected deaths in all studies, it would appear that the excess of malignancies at nonhepatic sites is less than the excess of liver tumors. Data presented elsewhere in this volume (Nicholson and Henneberger, 1983) suggest that exposure reductions in 1974 may have virtually eliminated the VC-associated risk of liver cancer if the current U.S. standard is met. To the extent that VC exposure is associated with other cancers, a similar risk reduction would be expected. Raynaud's phenomenon, acroosteolysis, scleroderma-like skin lesions, hepato- and splenomegaly with noncirrhotic hepatic fibrosis, and severe portal hypertension have been associated with past heavy exposures to VC. Evidence exists that the liver disease and portal hypertension may progress following cessation of exposure. However, all of the above syndromes were found largely in heavily exposed individuals. Their occurrence would be much less likely in workers exposed only to concentrations currently allowed. Pulmonary deficits, X-ray abnormalities, and, perhaps, lung cancer have been associated with VC/PVC exposure. Because of the possible contribution of PVC dust to these findings, engineering controls during polymer drying, bagging and usage are warranted.

  15. Migration levels of PVC plasticisers: Effect of ionising radiation treatment.

    PubMed

    Zygoura, Panagiota D; Paleologos, Evangelos K; Kontominas, Michael G

    2011-09-01

    Migration levels of commercial plasticisers [di-(2-ethylhexyl) adipate (DEHA) and acetyl tributyl citrate (ATBC)] from polyvinyl chloride (PVC) film into the EU specified aqueous food simulants (distilled water, 3% w/v acetic acid and 10% v/v ethanol) were monitored as a function of time. Migration testing was carried out at 40°C for 10days (EEC, 1993). Determination of the analytes was performed by applying the analytical methodology based on surfactant (Triton X-114) mediated extraction prior to gas chromatographic-flame ionisation detection (GC-FID) recently proposed by our group. The study focuses on the determination of the effect of gamma radiation on plasticiser migration into the selected simulants. PVC cling film used was subjected to ionising treatment with a [(60)Co] source at doses equal to 5, 15 and 25kGy. DEHA and ATBC migration into the EU aqueous simulating solvents was limited, yielding final concentrations in the respective ranges 10-100μg/l and 171-422μg/l; hence, ATBC demonstrated a stronger interaction with all three simulants compared to DEHA. Migration data, with respect to ATBC, showed that the most aggressive simulant seemed to be the 10% ethanol, while in the case of DEHA the 3% aqueous acetic acid exhibited the highest extraction efficiency; distilled water demonstrated the lowest migration in both cases. With regard to PVC treatment with gamma rays, high radiation doses up to 25kGy produced a statistically significant (p<0.05) effect on the migration of both plasticisers.

  16. Performance enhancement of polyvinyl chloride ultrafiltration membrane modified with graphene oxide.

    PubMed

    Zhao, Yuanyuan; Lu, Jiaqi; Liu, Xuyang; Wang, Yudan; Lin, Jiuyang; Peng, Na; Li, Jingchun; Zhao, Fangbo

    2016-10-15

    A novel polyvinyl chloride (PVC) membrane was modified with graphene oxide (GO) via phase inversion method to improve its hydrophilicity and mechanical properties. The GO presented a large amount of hydrophilic groups after the modification through the modified Hummers method. It was observed that with the addition of low fraction of GO powder, the GO/PVC hybrid membranes exhibited a significant enhancement in hydrophilicity, water flux, and mechanical properties. With optimal dosage (0.1wt%), the pure water flux of GO/PVC membrane increased from 232.6L/(m(2)hbar) to 430.0L/(m(2)hbar) and the tensile strength increased from 231.3cN to 305.3cN. The improved properties of the PVC/GO hybrid membranes are mainly attributed to the strong hydrophilicity of functional groups on the GO surface, indicating that GO has a promising candidate for modification of PVC ultrafiltration membranes in wastewater treatment.

  17. Neutron and gamma attenuation in polyethylene and PVC mortars

    SciTech Connect

    Abdul-Majid, S.; Abulfaraj, W.H.; Othman, F. )

    1991-01-01

    Concrete is a basic building material widely used in radiation shielding. As water in ordinary concrete is only {approximately}6% by weight, fast neutrons undergo a medium to poor moderation process. Special types of mortar were developed in which polyethylene ((CH{sub 2})n) or PVC ((CH{sub 2}-CH-Cl)n) pellets were used instead of coarse aggregates in ordinary concrete. Both of these polymers are rich in hydrogen and carbon moderator atoms. Preparation methods and resulting material properties are discussed.

  18. Iron(III) protoporphyrin IX complexes of the antimalarial Cinchona alkaloids quinine and quinidine.

    PubMed

    de Villiers, Katherine A; Gildenhuys, Johandie; le Roex, Tanya

    2012-04-20

    The antimalarial properties of the Cinchona alkaloids quinine and quinidine have been known for decades. Surprisingly, 9-epiquinine and 9-epiquinidine are almost inactive. A lack of definitive structural information has precluded a clear understanding of the relationship between molecular structure and biological activity. In the current study, we have determined by single crystal X-ray diffraction the structures of the complexes formed between quinine and quinidine and iron(III) protoporphyrin IX (Fe(III)PPIX). Coordination of the alkaloid to the Fe(III) center is a key feature of both complexes, and further stability is provided by an intramolecular hydrogen bond formed between a propionate side chain of Fe(III)PPIX and the protonated quinuclidine nitrogen atom of either alkaloid. These interactions are believed to be responsible for inhibiting the incorporation of Fe(III)PPIX into crystalline hemozoin during its in vivo detoxification. It is also possible to rationalize the greater activity of quinidine compared to that of quinine.

  19. Quantitative determination of some pharmaceutical piperazine derivatives through complexation with iron(III) chloride.

    PubMed

    Abou-Attia, F M; Issa, Y M; Abdel-Gawad, F M; Abdel-Hamid, S M

    2003-08-01

    A simple, accurate and sensitive spectrophotometric method has been developed for the determination of three pharmaceutical piperazine derivatives, namely ketoconazole (KC), trimetazidine hydrochloride (TMH) and piribedil (PD). This method is based on the formation of yellow orange complexes between iron(III) chloride and the investigated drugs. The optimum reaction conditions, spectral characteristics, conditional stability constants and composition of the water soluble complexes have been established. The method permits the determination of KC, TMH and PD over a concentration range 1-15, 1-12 and 1-12 microg ml(-1), respectively. Sandell sensitivity is found to be 0.016, 0.013 and 0.013 microg cm(-2) for KC, TMH and PD, respectively. The method was sensitive, simple, reproducible and accurate within +/-1.5%. The method is applicable to the assay of the three drugs under investigation in different dosage forms and the results are in good agreement with those obtained by the official methods (USP and JP).

  20. Stabilization through precipitation in a system of colloidal iron(III) pyrophosphate salts.

    PubMed

    van Leeuwen, Y Mikal; Velikov, Krassimir P; Kegel, Willem K

    2012-09-01

    The ionic strength of a solution decreases during the precipitation of an insoluble salt, which can cause an initially unstable colloidal system to stabilize during its formation. We show this effect in the precipitation and aging of colloidal iron(III) pyrophosphate, where we observe two distinct stages in the aggregation process. The first stage is the formation of nanoparticles that immediately aggregate into clusters with sizes on the order of 200 nm. In the second stage these clusters slowly grow in size but remain in dispersion for days, even months for dialyzed systems. Eventually these clusters become macroscopically large and sediment out of dispersion. Noting the clear instability of the nanoparticles, it is interesting to find two stages in their aggregation even without the use of additives such as surface active molecules. This is explained by accounting for the rapid decrease of ionic strength during precipitation, rendering the nanoparticles relatively stable when precipitation is complete. Calculating the interaction potentials for this scenario we find good agreement with the experimental observations. These results indicate that coupling of ionic strength to aggregation state can be significant and should be taken into account when considering colloidal stability of insoluble salts.

  1. Iron(III) Fluorinated Porphyrins: Greener Chemistry from Synthesis to Oxidative Catalysis Reactions.

    PubMed

    Rebelo, Susana L H; Silva, André M N; Medforth, Craig J; Freire, Cristina

    2016-04-12

    Iron(III) fluorinated porphyrins play a central role in the biomimetics of heme enzymes and enable cleaner routes to the oxidation of organic compounds. The present work reports significant improvements in the eco-compatibility of the synthesis of 5,10,15,20-tetrakis-pentafluorophenylporphyrin (H₂TPFPP) and the corresponding iron complex [Fe(TPFPP)Cl], and the use of [Fe(TPFPP)Cl] as an oxidation catalyst in green conditions. The preparations of H₂TPFPP and [Fe(TPFPP)Cl] typically use toxic solvents and can be made significantly greener and simpler using microwave heating and optimization of the reaction conditions. In the optimized procedure it was possible to eliminate nitrobenzene from the porphyrin synthesis and replace DMF by acetonitrile in the metalation reaction, concomitant with a significant reduction of reaction time and simplification of the purification procedure. The Fe(III)porphyrin is then tested as catalyst in the selective oxidation of aromatics at room temperature using a green oxidant (hydrogen peroxide) and green solvent (ethanol). Efficient epoxidation of indene and selective oxidation of 3,5-dimethylphenol and naphthalene to the corresponding quinones is observed.

  2. Synthesis, crystal structure and magnetism of iron(III) and manganese(III) dipicolinates with pyridinemethanols

    NASA Astrophysics Data System (ADS)

    Uhrecký, Róbert; Pavlik, Ján; Růžičková, Zdeňka; Dlháň, Ľubor; Koman, Marian; Boča, Roman; Moncoľ, Ján

    2014-11-01

    Four ionic iron(III) and manganese(III) dipicolinato complexes of the formula (2-pymeH) [FeIII(dipic)2]ṡ[FeIII(H2O)2Cl(dipic)]ṡ2H2O, (3-pymeH)[MnIII(dipic)2]ṡ1.5H2O, (4-pymeH)[FeIII(dipic)2]ṡ2H2O and (4-pymeH)[MnIII(dipic)2]ṡ2H2O, where H2dipic = pyridine-2,6-dicarboxylic acid, 2-pyme = 2-pyridinemethanol, 3-pyme = 3-pyridinemethanol, 4-pyme = 4-pyridinemethanol, have been prepared and characterized by the single-crystal X-ray structure analysis, infrared spectroscopy and magnetic measurements. The magnetic data were fitted to a zero-field splitting model revealing a slight magnetic anisotropy for Mn(III) systems. The molecular field correction was consistently formulated and included in the analysis for both, magnetic susceptibility and magnetization data.

  3. Hydrogen peroxide decomposition by a non-heme iron(III) catalase mimic: a DFT study.

    PubMed

    Sicking, Willi; Korth, Hans-Gert; Jansen, Georg; de Groot, Herbert; Sustmann, Reiner

    2007-01-01

    Non-heme iron(III) complexes of 14-membered tetraaza macrocycles have previously been found to catalytically decompose hydrogen peroxide to water and molecular oxygen, like the native enzyme catalase. Here the mechanism of this reaction is theoretically investigated by DFT calculations at the (U)B3LYP/6-31G* level, with focus on the reactivity of the possible spin states of the FeIII complexes. The computations suggest that H2O2 decomposition follows a homolytic route with intermediate formation of an iron(IV) oxo radical cation species (L.+FeIV==O) that resembles Compound I of natural iron porphyrin systems. Along the whole catalytic cycle, no significant energetic differences were found for the reaction proceeding on the doublet (S=1/2) or on the quartet (S=3/2) hypersurface, with the single exception of the rate-determining O--O bond cleavage of the first associated hydrogen peroxide molecule, for which reaction via the doublet state is preferred. The sextet (S=5/2) state of the FeIII complexes appears to be unreactive in catalase-like reactions.

  4. Optimization of the thickness of a conducting polymer, polyaniline, deposited on the surface of poly(vinyl chloride) membranes: a new way to improve their potentiometric response.

    PubMed

    Shishkanova, T V; Matejka, P; Král, V; Sedenková, I; Trchová, M; Stejskal, J

    2008-08-29

    Repeated depositions of polyaniline (PANI) have been used to control the thickness of the polymeric film deposited on poly(vinyl chloride) (PVC) membrane surface. The oxidation of aniline was carried out in a dispersion mode, i.e. in the presence of poly(N-vinylpyrrolidone) (PVP). Two kinds of PVC were used for this purpose: a non-plasticized PVC for the study of PANI deposition and PVC, plasticized with nitrophenyl octyl ether (NPOE), as a prototype of a liquid membrane electrode. The results of UV-visible and FTIR spectroscopies and electron microscopy showed that (1) the film thickness increased by about equal increments of approximately 40 nm after each polymerization, and (2) the interface with PVC was constituted by PANI film and adhering PANI-PVP colloidal particles. The various thicknesses of the deposited PANI films affected the potentiometric response of the NPOE/PVC membrane with and without an anion-exchanger. The potentiometric anionic response was observed with a minimal thickness of PANI film on the blank NPOE/PVC membrane. Sensitivity of the PANI film to pH occurred only with a blank NPOE/PVC membrane coated with a thick polymeric film, while it was strongly suppressed by the presence of a lipophilic anion-exchanger, tridodecylmethylammonium chloride (TDDMACl), in the membrane, regardless of the thickness of the polymer film. The thickness of the PANI film did not affect the anionic selectivity pattern of TDDMACl-based membranes to any great extent, but its presence improved and stabilized their potentiometric characteristics (sensitivity, linear-response range).

  5. PVC-based composite material containing recycled non-metallic printed circuit board (PCB) powders.

    PubMed

    Wang, Xinjie; Guo, Yuwen; Liu, Jingyang; Qiao, Qi; Liang, Jijun

    2010-12-01

    The study is directed to the use of non-metallic powders obtained from comminuted recycled paper-based printed circuit boards (PCBs) as an additive to polyvinyl chloride (PVC) substrate. The physical properties of the non-metallic PCB (NMPCB) powders were measured, and the morphological, mechanical and thermal properties of the NMPCB/PVC composite material were investigated. The results show that recycled NMPCB powders, when added below a threshold, tended to increase the tensile strength and bending strength of PVC. When 20 wt% NMPCB powders (relative to the substrate PVC) of an average diameter of 0.08 mm were added, the composite tensile strength and bending strength reached 22.6 MPa and 39.83 MPa, respectively, representing 107.2% and 123.1% improvement over pure PVC. The elongation at break of the composite material reached 151.94% of that of pure PVC, while the Vicat softening temperature of the composite material did not increase significantly compared to the pure PVC. The above results suggest that paper-based NMPCB powders, when used at appropriate amounts, can be effective for toughening PVC. Thus, this study suggests a new route for reusing paper-based NMPCB, which may have a significant beneficial environmental impact.

  6. CHARACTERIZATION OF CLEAN AND FOULED PERFORATED MEMBRANE DIFFUSERS

    EPA Science Inventory

    Laboratory analyses were conducted on plasticized PVC perforated membrane tube diffusers after varying periods in service at two different municipal wastewater treatment facilities. One set of diffusers from Cedar Creek, NY, was in service for 26 months. The other set from the ...

  7. Study of mechanical properties of polyvinyl chloride (PVC) and polystyrene (PS) polymers and their blends

    NASA Astrophysics Data System (ADS)

    Agarwal, Shalini; Saxena, N. S.; Agrawal, R.; Saraswat, Vibhav K.

    2013-06-01

    Presented work is an effort to observe the variation in mechanical properties of two thermoplastic materials PVC, PS and their blends. PVC and PS are taken in the ratio of 100:0, 70:30, 50:50, and 0:100. Mixing of PVC and PS is carried out by solution casting method using tetra hydro furan as solvent. Dynamical mechanical analyzer (DMA) is used to study mechanical properties. The storage modulus, loss modulus and mechanical loss factor (tan δ) are determined with temperature. The pallets of pure PS, PVC and their blends are scanned over a temperature range from room to 140 °C. The variation of modulus, tan δ of pure PVC & pure PS and their blends with temperature were studied. The observed variation in modulus and tan δ could be accounted for their thermal behavior and compositions.

  8. Characterization of the surface and the interphase of PVC-copper amine-treated wood composites

    NASA Astrophysics Data System (ADS)

    Jiang, Haihong; Kamdem, D. Pascal

    2010-05-01

    Contact angles and surface energy of wood, as well as interfacial shear strength between wood and polyvinyl chloride (PVC) were investigated and used to monitor the modifications generated on the surfaces of wood treated with a copper ethanolamine solution. An increase in surface energy of wood after treatments promotes wetting of PVC on wood surfaces. Improved interfacial shear strength between treated wood and PVC matrix can be attributed to the formation of a stronger wood-PVC interphase. This suggests that treatment may be used to improve the adhesion between wood surface and PVC in the formulation of wood fiber composites to yield products with enhanced mechanical properties and better biological and physical performance against decay and insect destroying wood.

  9. PVC biodeterioration and DEHP leaching by DEHP-degrading bacteria

    PubMed Central

    Latorre, Isomar; Hwang, Sangchul; Sevillano, Maria; Montalvo-Rodriguez, Rafael

    2012-01-01

    Newly isolated, not previously reported, di-(2-ethylhexyl) phthalate (DEHP)-degraders were augmented to assess their role in polyvinyl chloride (PVC) shower curtain deterioration and DEHP leaching. The biofilms that developed on the surfaces of the bioaugmented shower curtains with Gram-positive strains LHM1 and LHM2 were thicker than those of the biostimulated and Gram-negative strain LHM3-augmented shower curtains. The first derivative thermogravimetric (DTG) peaks of the bioaugmented shower curtains with the Gram-positive bacteria were observed at ~287°C, whereas the control and Gram-negative strain LHM3-augmented shower curtains were detected at ~283°C. This slight delay in the first DTG peak temperature is indicative of lower plasticizer concentrations in the shower curtains that were bioaugmented with Gram positive bacteria. Despite bioaugmentation with DEHP-degraders, aqueous solutions of the bioaugmentation reactors were not DEHP-free due probably to the presence of co-solutes that must have supported microbial growth. Generally, the bioaugmented reactors with the Gram-positive strains LHM1 and LHM2 had greater aqueous DEHP concentrations in the first-half (<3 wk) of the biodeterioration experiment than the biostimulated and strain LHM3-augmented reactors. Therefore, strains LHM1 and LHM2 may play an important role in DEHP leaching to the environment and PVC biodeterioration. PMID:22736894

  10. Comparative Fatigue Lives of Rubber and PVC Wiper Cylindrical Coatings

    NASA Technical Reports Server (NTRS)

    Vlcek, Brian L.; Hendricks, Robert C.; Zaretsky, Erwin V.; Savage, Michael

    2002-01-01

    Three coating materials for rotating cylindrical-coated wiping rollers were fatigue tested in 2 Intaglio printing presses. The coatings were a hard, cross-linked, plasticized PVC thermoset (P-series); a plasticized PVC (A-series); and a hard, nitryl rubber (R-series). Both 2- and 3-parameter Weibull analyses as well as a cost-benefit analysis were performed. The mean value of life for the R-series coating is 24 and 9 times longer than the P- and A-series coatings, respectively. Both the cost and replacement rate for the R-series coating was significantly less than those for the P- and A-series coatings. At a very high probability of survival the R-series coating is approximately 2 and 6 times the lives of the P- and A-series, respectively, before the first failure occurs. Where all coatings are run to failure, using the mean (life) time between removal (MTBR) for each coating to calculate the number of replacements and costs provides qualitatively similar results to those using a Weibull analysis.

  11. Comparison of the kinetic laws of the dissolution of bauxite and aluminum and iron(III) oxides and hydroxides in hydrochloric acid

    NASA Astrophysics Data System (ADS)

    Gololobova, E. G.; Gorichev, I. G.; Lainer, Yu. A.; Kozlov, K. V.

    2013-07-01

    The influence of the temperature and concentration of a hydrochloric acid solution on the dissolution kinetics of aluminum and iron(III) oxides and hydroxides and a natural sample of aluminum-containing raw materials, bauxite, is studied. The rate W of the transition of iron(III) ions from bauxite is higher than the rate of aluminum ion transition. The dependence of the fraction of a dissolved solid phase on time τ of dissolution of the oxides and hydroxides is determined, α = 1 — exp(- Asinh( Wτ)). The solubility of iron(III) chloride increases and that of aluminum chloride decreases as the HCl concentration increases. An empirical equation is proposed for the description of the dependence of the process rate on a series of parameters,.

  12. Hydration effects and antifouling properties of poly(vinyl chloride-co-PEGMA) membranes studied using molecular dynamics simulations

    NASA Astrophysics Data System (ADS)

    Shaikh, Abdul Rajjak; Rajabzadeh, Saeid; Matsuo, Ryuichi; Takaba, Hiromitsu; Matsuyama, Hideto

    2016-04-01

    Polyvinyl chloride (PVC) membranes are widely used in water treatment because of their low cost and chemical stability. However, PVC membranes can become fouled, and this restricts their applications in membrane technology. In order to enhance the antifouling property of PVC membranes, copolymers such as poly(vinyl chloride-co-poly(ethylene glycol)methyl ether methacrylate) (poly(VC-co-PEGMA)) with different PEGMA segment percentages were synthesized in our previous work. Experimentally, it was observed that the poly(VC-co-PEGMA) copolymer has better antifouling properties than those of PVC membranes. Here, we explore effect of the PEGMA segment percentage on the surface hydration properties of poly(VC-co-PEGMA) copolymers. Density functional theory calculations and molecular dynamics simulations were carried out to understand the interactions between PVC and PEGMA. Model structures of these systems were validated by comparing the simulated values of their volumetric properties with the experimental values. MD studies showed that increasing PEGMA percentage in the copolymer increases the interaction with water molecules, leading to improved resistance to fouling. The antifouling mechanism is also discussed with respect to surface hydration and water dynamicity. This study could form a basis for the systematic studies of polymeric membranes as well as their stability from the extent of solvent-polymer, solvent-solvent, and polymer-polymer interactions.

  13. Binding Studies of a New Water-Soluble Iron(III) Schiff Base Complex to DNA Using Multispectroscopic Methods

    PubMed Central

    Shahabadi, Nahid; Ghasemian, Zeinab; Hadidi, Saba

    2012-01-01

    A novel iron(III) complex [Fe(SF)](ClO4)3.2H2O; in which SF = N,N0-bis{5-[(triphenylphosphonium chloride)-methyl] salicylidene}-o-phenylenediamine) has been synthesized and characterized using different physicochemical methods. The binding of this complex with calf thymus (CT) DNA was investigated by circular dichroism, absorption studies, emission spectroscopy, voltammetric studies, and viscosity measurements. The results showed that this complex can bind to DNA via external and groove binding modes. PMID:22899896

  14. New lipophilic 3-hydroxy-4-pyridinonate iron(III) complexes: synthesis and EXAFS structural characterisation.

    PubMed

    Schlindwein, Walkiria; Waltham, Emma; Burgess, John; Binsted, Norman; Nunes, Ana; Leite, Andreia; Rangel, Maria

    2006-03-14

    New tris-iron(III) chelates of 3-hydroxy-4-pyridinone ligands derived from maltol (3-hydroxy-2-methyl-4-pyrone) or ethylmaltol (2-ethyl-3-hydroxy-4-pyrone), including a variety of N-aryl (phenyl, 4'-tolyl, 4'-(n-butyl)phenyl, 4'-(n-hexyl)phenyl) and N-benzyl (4'-methylbenzyl, 4'-fluorobenzyl and 4'-(trifluoromethyl)benzylamine) substituents on the nitrogen atom of the pyridinone ring, have been prepared. Characterization by C,H,N elemental analysis and thermogravimetric measurements indicates that most of the complexes are obtained as hydrates of general formula ML3.xH2O. Structural characterization of these difficult to crystallize lipophilic complexes has been achieved by EXAFS spectroscopy. Solutions of iron(III) complexes of maltol, ethylmaltol, 1,2-dimethyl-3-hydroxy-4-pyridinone and 1-phenyl-2-methyl-3-hydroxy-4-pyridinone in methanol-water mixtures were also examined by EXAFS. Distances from the central atom to ligand atoms, within 6 A of the metal, have been determined in the solid and solution samples and the results show that the structure observed in the powder is maintained in solution. The local structure around the metal centre, bond distances and bond angles, does not change significantly with variable lipophilicity, thus indicating that ligands may be tailored according to specific needs without altering their chelation properties. EXAFS data analysis for this set of tris-iron(III) compounds illustrates the important contribution of both intra-ligand and inter-ligand multiple scattering pathways through the metal centre to a peak observed in the FT spectrum at twice the metal ligand distance (approximately 4 A). The present results demonstrate that EXAFS features at twice the metal-ligand distance are valuable in the assignment of molecular geometry and that location of hydration water molecules, by EXAFS analysis, is limited by the geometry of the complexes, in particular for those in which ligands containing phenyl rings are present.

  15. The role of transferrin in actinide(IV) uptake: comparison with iron(III).

    PubMed

    Jeanson, Aurélie; Ferrand, M; Funke, Harald; Hennig, Christoph; Moisy, Philippe; Solari, Pier Lorenzo; Vidaud, Claude; Den Auwer, Christophe

    2010-01-25

    The impact of actinides on living organisms has been the subject of numerous studies since the 1950s. From a general point of view, these studies show that actinides are chemical poisons as well as radiological hazards. Actinides in plasma are assumed to be mainly complexed to transferrin, the iron carrier protein. This paper casts light on the uptake of actinides(IV) (thorium, neptunium, plutonium) by transferrin, focusing on the pH dependence of the interaction and on a molecular description of the cation binding site in the protein. Their behavior is compared with that of iron(III), the endogenous transferrin cation, from a structural point of view. Complementary spectroscopic techniques (UV/Vis spectrophotometry, microfiltration coupled with gamma spectrometry, and X-ray absorption fine structure) have been combined in order to propose a structural model for the actinide-binding site in transferrin. Comparison of our results with data available on holotransferrin suggests some similarities between the behavior of Fe(III) and Np(IV)/Pu(IV)/ Np(IV) is not complexed at pH <7, whereas at pH approximately 7.4 complexation can be regarded as quantitative. This pH effect is consistent with the in vivo transferrin "cycle". Pu(IV) also appears to be quantitatively bound by apotransferrin at around pH approximately 7.5, whereas Th(IV) was never complexed under our experimental conditions. EXAFS data at the actinide edge have allowed a structural model of the actinide binding site to be elaborated: at least one tyrosine residue could participate in the actinide coordination sphere (two for iron), forming a mixed hydroxo-transferrin complex in which actinides are bound with transferrin both through An-tyrosine and through An--OH bonds. A description of interatomic distances is provided.

  16. Surface water enhances the uptake and photoreactivity of gaseous catechol on solid iron(III) chloride.

    PubMed

    Tofan-Lazar, Julia; Al-Abadleh, Hind A

    2014-01-01

    Uptake and photoreactivity of catechol-Fe complexes are investigated at the gas/solid interface under humid and dry conditions, along with the nature of the hydrogen-bonding network of adsorbed water. Catechol was chosen as a simple model for organics in aerosols. Iron chloride was used to distinguish ionic mobility from binding to coordinated iron(III) in hematite. Studies were conducted using diffuse reflectance infrared Fourier transform spectroscopy as a function of irradiation time. Results show that adsorbed water at 30% relative humidity (RH), not light, increases the concentration of adsorbed catechol by a factor of 3 over 60 min relative to dry conditions. Also, our data show that, at 30% RH and under light and dark conditions, growth factors describing the concentration of adsorbed catechol are very similar suggesting that light does not significantly enhance the uptake of catechol vapor on FeCl3. Surface water also enhances the initial photodecay kinetics of catechol-Fe complexes at 30% RH by a factor of 10 relative to control experiments (RH < 1%, or no FeCl3 under humid conditions). Absorptions assigned to carbonyl groups were not observed with irradiation time, which was explained by the dominance of FeCl(2+) species relative to FeOH(2+) in the highly acidic "quasi-liquid" phase at 30% RH. Clear differences in the hydrogen-bonding network upon gaseous catechol uptake are observed in the dark and light and during the photodecay of adsorbed catechol. The implications of these results on our understanding of interfacial processes in aged iron-containing surfaces are discussed.

  17. Properties of blends for profiles and semi-rigid films made of PVC nanocomposites produced in pilot scale

    NASA Astrophysics Data System (ADS)

    Obloj-Muzaj, Maria; Abramowicz, Agnieszka; Kumosinski, Marcin; Zielecka, Maria; Kozakiewicz, Janusz; Gorska, Agnieszka

    2016-05-01

    PVC nanocomposites containing 0.5 wt. %/VCM of either nanosilica or hybrid core/shell type nanofiller were produced in-situ in suspension polymerisation. Significant increase in impact strength of PVC composites obtained was observed (higher 25 - 60 % in comparison with PVC). The amount of impact modifier in selected rigid PVC blends (e.g. in window profiles) could be significantly reduced (≥ 50 %). Tensile and flexural properties of nanocomposites were similar to PVC, however, at smaller amount of impact modifier other mechanical properties improve. Tear resistance of rigid films was better.

  18. Interaction of plasma proteins with commercial protein repellent polyvinyl chloride (PVC): a word of caution.

    PubMed

    De Somer, F; Van Landschoot, A; Van Nooten, G; Delanghe, J

    2008-07-01

    Protein adsorption onto polymers remains a problem. In recent years, several protein-repellent PVC tubings have been developed. Although several studies report the interaction between plasma coagulation proteins and PVC, few address the interaction with other plasma proteins. Two commercial brands of untreated medical grade PVC tubing, phosphorylcholine-coated PVC tubing, triblock-copolymer (polycaprolactone-polydimethylsiloxane-polycaprolactone)-treated PVC tubing and poly-2-methoxyethylacrylate (PMEA)-coated tubing were exposed for 60 minutes to human plasma. A broad spectrum of plasma proteins was found on all tubing. The adsorbed albumin to total protein ratio is lower than the similar ratio in plasma while alpha1 and alpha2 globulins are over-represented in the protein spectrum. On PMEA tubing, not only alpha globulins, but also beta and gamma globulins, are found in high concentrations in the adsorbed protein. PMEA tubing and uncoated PVC tubing of brand B had a higher amount of protein adsorbed compared against all other tubing (p < 0.05). There were no statistical differences in protein adsorption between the triblock-copolymer-treated tubing, the phosphorylcholine-coated tubing and the uncoated PVC tubing of brand A. The average thickness of the protein layer was 23 nm. Plasma protein adsorption still exists on uncoated and protein-repellent tubing and can initiate a systemic inflammatory reaction.

  19. Isolation and molecular characterization of polyvinyl chloride (PVC) plastic degrading fungal isolates.

    PubMed

    Ali, Muhammad Ishtiaq; Ahmed, Safia; Robson, Geoff; Javed, Imran; Ali, Naeem; Atiq, Naima; Hameed, Abdul

    2014-01-01

    The recalcitrant nature of polyvinyl chloride creates serious environmental concerns during manufacturing and waste disposal. The present study was aimed to isolate and screen different soil fungi having potential to biodegrade PVC films. After 10 months of soil burial experiment, it was observed that a number of fungal strains were flourishing on PVC films. On morphological as well as on 18rRNA gene sequence and phylogenetic basis they were identified as Phanerochaete chrysosporium PV1, Lentinus tigrinus PV2, Aspergillus niger PV3, and Aspergillus sydowii PV4. The biodegradation ability of these fungal isolates was further checked in shake flask experiments by taking thin films of PVC (C source) in mineral salt medium. A significant change in color and surface deterioration of PVC films was confirmed through visual observation and Scanning electron microscopy. During shake flask experiments, P. chrysosporium PV1 produced maximum biomass of about 2.57 mg ml(-1) followed by A. niger PV3. P. chrysosporium PV1 showed significant reduction (178,292 Da(-1)) in Molecular weight of the PVC film than control (200,000 Da(-1)) by gel permeation chromatography. Furthermore more Fourier transform infrared spectroscopy and nuclear magnetic resonance also revealed structural changes in the PVC. It was concluded that isolated fungal strains have significant potential for biodegradation of PVC plastics.

  20. Phase Transition and Mechanical Properties of PS/PVC/CdS Polymeric Nanocomposites

    NASA Astrophysics Data System (ADS)

    Mathur, Vishal; Dixit, Manasvi; Saxena, N. S.; Sharma, Kananbala

    2010-06-01

    The present study reports the phase transition temperature and mechanical properties of CdS dispersed PS-PVC nanocomposite through Dynamic Mechanical Analyzer (DMA). Thick films of polymeric nanocomposites have been synthesized by dispersing nano-filler particles of CdS in PS/PVC binary blend matrix. The surface morphology of PS/PVC blend samples has been characterized by Scanning Electron Microscopy (SEM) while the nanostructure of the CdS filler in PS/PVC/CdS composite has been ascertained through small angle X-ray Diffraction (XRD) technique. The phase transition temperature study of PS/PVC polymeric blends reveals that glass transition temperature, Tg, of the PS phase shifts towards lower temperature with the increase in PVC content in the blend whereas for CdS embedded polymeric phases of blends i.e. for PS/PVC/CdS samples, an increase in respective Tg values have been observed. This is suggestive to the fact that phase transition temperature and mechanical properties have been significantly influenced through the dispersion of CdS nano-filler particles in the studied polymeric blend series.

  1. Effect of flexibility of grafted polymer on the morphology and property of nanosilica/PVC composites

    NASA Astrophysics Data System (ADS)

    Zhu, Aiping; Cai, Aiyun; Zhou, Weidong; Shi, Zhehua

    2008-04-01

    In this study, poly(methyl methacrylate)-grafted-nanosilica (PMMA-g-silica) and a copolymer of styrene (St), n-butyl acrylate (BA) and acrylic acid (AA)-grafted-nanosilica (PSBA-g-silica) hybrid nanoparticles were prepared by using a heterophase polymerization technique in an aqueous system. The grafted polymers made up approximately 50 wt.% of the resulted hybrid nanoparticles which showed a spherical and well-dispersed morphology. The silica hybrid nanoparticles were subsequently used as fillers in a poly(vinyl chloride) (PVC) matrix to fabricate PVC nanocomposite. Morphology study of PVC nanocomposites revealed that both PMMA- and PSBA-grafted-silica had an adhesive interface between the silica and PVC. The tensile strength and elongation to break were found to be improved significantly in comparison with that of untreated nanosilica/PVC composites. Finally our results clearly demonstrated that the properties (e.g. chain flexibility, composition) of the grafted polymer in the hybrid nanoparticles could significantly affect the dispersion behavior of hybrid nanoparticles in PVC matrix, dynamic mechanical thermal properties and mechanical properties of the resulted PVC composites.

  2. Upgrading of PVC rich wastes by magnetic density separation and hyperspectral imaging quality control.

    PubMed

    Luciani, Valentina; Bonifazi, Giuseppe; Rem, Peter; Serranti, Silvia

    2015-11-01

    Polyvinylchloride (PVC) is one of the most produced polymers in Europe, with a share of 11% in terms of mass (8 milliontons) of total polymer consumption, but in 2010 only 5% of the total PVC production came from recycled materials, where other polymer recycling achieves a level of 15% on average. In order to find an innovative process to extract PVC from window frames waste, a combination of two innovative technologies was tested: magnetic density separation (MDS) and hyperspectral imaging (HSI). By its nature, MDS is a flexible high precision density separation technology that is applicable to any mixture of polymers and contaminants with non-overlapping densities. As PVC has a very distinctive high density, this technology was tested to obtain high-grade PVC pre-concentrates from window frame waste. HSI was used to perform a quality control of the products obtained by MDS showing that PVC was clearly discriminated from unwanted rubber particles of different colors. The results showed that the combined application of MDS and HSI techniques allowed to separate and to check the purity of PVC from window frame waste.

  3. Layered and intercalated hydrotalcite-like materials as thermal stabilizers in PVC resin

    NASA Astrophysics Data System (ADS)

    Lin, Yanjun; Wang, Jianrong; Evans, David G.; Li, Dianqing

    2006-05-01

    In the light of the accepted mechanism of thermal stabilization of PVC by layered double hydroxides (LDHs), the layer cations and interlayer counterions in LDHs were tailored to give MgZnAl-CO3-LDH and MgZnAl-maleate-LDH. These materials were characterized by XRD, FT-IR, and TG DTA. The thermal stability of PVC composites containing different LDH additives was tested in sheets having a thickness of about 1 mm. The results showed that compared with MgAl-CO3-LDH, MgZnAl-CO3-LDH enhances the thermal stability of PVC in terms of both long-term stability and early coloring. After intercalation of maleate in the LDH by reaction of maleic acid with the MgZnAl-CO3-LDH precursor, the interlayer distance increases from 0.75 to 1.11 nm. Since Cl- promotes the autocatalytic dehydrochlorination of PVC, which is responsible for its degradation, an increased interlayer distance should facilitate entry of Cl- into the interlayer galleries and inhibit the decomposition of PVC. In addition, maleic acid has a conjugated C=C double bond which can react with double bond formed in the dehydrochlorination of PVC and thus further inhibit the autocatalytic degradation reaction. The results show that the early coloring of PVC is markedly improved and the long-term stability slightly reduced by addition of the MgZnAl-maleate-LDH.

  4. Molecular surface structural changes of plasticized PVC materials after plasma treatment.

    PubMed

    Zhang, Xiaoxian; Zhang, Chi; Hankett, Jeanne M; Chen, Zhan

    2013-03-26

    In this research, a variety of analytical techniques including sum frequency generation vibrational spectroscopy (SFG), coherent anti-Stokes Raman spectroscopy (CARS), and X-ray photoelectron spectroscopy (XPS) have been employed to investigate the surface and bulk structures of phthalate plasticized poly(vinyl chloride) (PVC) at the molecular level. Two types of phthalate molecules with different chain lengths, diethyl phthalate (DEP) and dibutyl phthalate (DBP), mixed with PVC in various weight ratios were examined to verify their different surface and bulk behaviors. The effects of oxygen and argon plasma treatment on PVC/DBP and PVC/DEP hybrid films were investigated on both the surface and bulk of films using SFG and CARS to evaluate the different plasticizer migration processes. Without plasma treatment, SFG results indicated that more plasticizers segregate to the surface at higher plasticizer bulk concentrations. SFG studies also demonstrated the presence of phthalates on the surface even at very low bulk concentration (5 wt %). Additionally, the results gathered from SFG, CARS, and XPS experiments suggested that the PVC/DEP system was unstable, and DEP molecules could leach out from the PVC under low vacuum after several minutes. In contrast, the PVC/DBP system was more stable; the migration process of DBP out of PVC could be effectively suppressed after oxygen plasma treatment. XPS results indicated the increase of C═O/C-O groups and decrease of C-Cl functionalities on the polymer surface after oxygen plasma treatment. The XPS results also suggested that exposure to argon plasma induced chemical bond breaking and formation of cross-linking or unsaturated groups with chain scission on the surface. Finally, our results indicate the potential risk of using DEP molecules in PVC since DEP can easily leach out from the polymeric bulk.

  5. Rapid and sensitive spectrophotometric determination of trace amounts of iron(III) using leuco Xylene cyanol FF.

    PubMed

    Kiran Kumar, T N; Revanasiddappa, H D

    2003-08-01

    A new, simple, sensitive, and reliable method is presented for the rapid spectrophotometric determination of trace amounts of iron(III) using leuco Xylene cyanol FF. The method is based on the oxidation of leuco Xylene cyanol FF (LXCFF) to its blue form of xylene cyanol FF by iron(III) in sulfuric acid medium (pH 2.0-3.0), the absorbance of the formed dye is measured in an acetate buffer medium (pH()2.8-4.4) at 615 nm. The method obeys Beer's law over a concentration range of 0.15-0.9 microg mL(-1) iron, having a molar absorptivity of 5.6 x 10(4) L mol(-1) cm(-1) and a Sandell's sensitivity of 0.0001 microg cm(-2). The optimum reaction conditions and other analytical parameters have been evaluated. The developed method has been successfully applied to the determination of iron in water, soil, industrial effluent, plant material, pharmaceutical preparations, synthetic mixtures, and aluminum alloys.

  6. Effect of UV and gamma radiation on Rn222 permeation through polyvinyl chloride (PVC). Application to the packaging of radium sources for the purpose of storage

    NASA Astrophysics Data System (ADS)

    Tomasella, E.; Labed, V.; Klein, D.; Robé, M. C.; Cetier, Ph.; Chambaudet, A.

    1995-11-01

    Mining of uranium and thorium, as well as the use of radioactive sources in radiotherapy, have caused, during the 20th century, the production of waste with a varying concentration in long-lived radionucleides (particularly radium). This waste cannot be stored in traditional storage sites which will return to the public domain after 300 years, due to, on the one hand, the radium period (1620 years) and, on the other hand, the build-up of radon, its gaseous daughter. One solution, in order to optimize the packaging and storage of such products, could be to use successive barriers, made of polymer membranes, intended to limit radon emission. Laboratory tests have shown that polyvinyl chloride (PVC) greatly reduces radon emission from a radium source. However one should take into account the damage of the polymer in time, due to radioactive waste storage itself over long periods of time. Therefore, in order to check the durability of such barriers, PVC samples have been subjected to different accelerated ageing processes by exposure to ultra-violet (UV) radiations or gamma rays. We have determined the effect of such radiation of the samples using two approaches: — demonstration of structural changes using analytical method (Infra-red with Fourier Transform or IRTF), — study of variations in the radon permeation factor. In the first analysis, it seems that the UV irradiation, causes structural changes in the PVC as a function of the irradiation length of time. This leads first to an increase in the efficiency of the polymer as a "radon barrier", i.e. a reduction in its permeation factor (2.41 × 10 -12m 2s -1 for a non exposed membrane, against 3.30 × 10 -13m 2.s -1 for a membrane exposed during 284 hours, with an exposure rate of 62.5 W.m -2, thus a reduction by a factor 10 of the radon emission) then to a long-term weakness. The gamma irradiation (dose rate: 1.05 kGy.h -1, dose: 0.71 MGy) also causes a reduction in the permeation factor of PVC, but only by a

  7. Modulation of function in a minimalist heme-binding membrane protein.

    PubMed

    Shinde, Sandip; Cordova, Jeanine M; Woodrum, Brian W; Ghirlanda, Giovanna

    2012-04-01

    De novo designed heme-binding proteins have been used successfully to recapitulate features of natural hemoproteins. This approach has now been extended to membrane-soluble model proteins. Our group designed a functional hemoprotein, ME1, by engineering a bishistidine binding site into a natural membrane protein, glycophorin A (Cordova et al. in J Am Chem Soc 129:512-518, 2007). ME1 binds iron(III) protoporphyrin IX with submicromolar affinity, has a redox potential of -128 mV, and displays peroxidase activity. Here, we show the effect of aromatic residues in modulating the redox potential in the context of a membrane-soluble model system. We designed aromatic interactions with the heme through a single-point mutant, G25F, in which a phenylalanine is designed to dock against the porphyrin ring. This mutation results in roughly tenfold tighter binding to iron(III) protoporphyrin IX (K(d,app) = 6.5 × 10(-8) M), and lowers the redox potential of the cofactor to -172 mV. This work demonstrates that specific design features aimed at controlling the properties of bound cofactors can be introduced in a minimalist membrane hemoprotein model. The ability to modulate the redox potential of cofactors embedded in artificial membrane proteins is crucial for the design of electron transfer chains across membranes in functional photosynthetic devices.

  8. The Effect of Temperature and Ionic Strength on the Oxidation of Iodide by Iron(III): A Clock Reaction Kinetic Study

    ERIC Educational Resources Information Center

    Bauer, Jurica; Tomisic, Vladislav; Vrkljan, Petar B. A.

    2012-01-01

    A laboratory exercise has recently been reported in which the students use the initial rates method based on the clock reaction approach to deduce the rate law and propose a reaction mechanism for the oxidation of iodide by iron(III) ions. The same approach is used in the exercise proposed herein; the students determine the dependence of the…

  9. Removal of arsenic(III) and arsenic(IV) ions from aqueous solutions with lanthanum(III) salt and comparison with aluminum(III), calcium(II), and iron(III) salts

    SciTech Connect

    Tokunaga, S.; Yokoyama, S.; Wasay, S.A.

    1999-05-01

    Interactions of arsenic(III) and arsenic(V) ions with a lanthanum salt were studied with the aim of developing a new precipitation method for removal of arsenic from aqueous solutions. Performance was compared to those of aluminum, polyaluminum chloride (PAC), calcium, and iron(III) salts. Arsenic(III) was removed by iron(III) and lanthanum in a narrow pH range with less than 605 removal. Arsenic(V) was removed more efficiently by aluminum, PAC, iron(III), and lanthanum. Lanthanum was most effective, meeting Japanese effluent and drinking water standards by adding three times as much lanthanum as arsenic(V).

  10. Preparation of single-walled carbon nanotubes/polyvinylchloride membrane and its antibacterial property.

    PubMed

    Zhao, Fangbo; Qiu, Feng; Zhang, Xiaohui; Yu, Shuili; Kim, Han-Shin; Park, Hee-Deung; Takizawa, Satoshi; Wang, Peng

    2012-01-01

    Polyvinylchloride (PVC) ultrafiltration membranes were modified by blending with single-walled carbon nanotubes (SWCNTs) to improve the membranes' antibacterial property. Both modified and control samples were characterized for pore structure, roughness, hydrophilicity, permeability and mechanical properties. The membranes' antibacterial property was accessed with Escherichia coli as the model microbes by several methods. It was found that, after being blended with SWCNTs, the surface roughness of the modified membrane increased. Also, the surface hydrophilicity was improved. The membrane flux increased accordingly. But the membrane elongation decreased obviously with the SWCNTs addition. The modified membranes did not show the antibacterial property as expected in this research. There was no bacterial inhibition circle around the SWCNTs/PVC membrane coupons in the culture plates. There were no morphological differences of the cells on the control and the modified membranes. Hoechst 33342/propidium iodide stain test showed that there were more than 90% living bacterial cells which could grow on the SWCNTs/PVC membranes. This study suggests that the polymer wrapping may reduce the SWCNTs' antibacterial property greatly.

  11. Nano-TiO2@Ag/PVC film with enhanced antibacterial activities and photocatalytic properties

    NASA Astrophysics Data System (ADS)

    Liu, Fajia; Liu, Hu; Li, Xiaoyun; Zhao, Huanyu; Zhu, Danping; Zheng, Yingying; Li, Chaorong

    2012-03-01

    The antibacterial and photocatalytic PVC film was prepared by doping heteronanostructure of TiO2 nanowire@Ag nanoparticles. TiO2 nanowire with 50-60 nm in diameter and 0.1 mm in length was prepared by a hydrothermal method, and Ag nanopartical about 5-10 nm in diameter was grafted on the surface of TiO2 nanowire evenly in the solution. The antimicrobial ability and the photocatalytic properties of the nano-TiO2@Ag/PVC film were systematically investigated by changing the influence factors such as the content of nano-TiO2@Ag, pH value and the cultivation condition. It confirmed that the nano-TiO2@Ag nanostructure could increase the antibacterial efficiency of the PVC film. Further, nano-TiO2@Ag/PVC film also showed enhanced photocatalytic activity to decompose Rhodmine B (RhB).

  12. Modification of medical grade PVC with N-vinylimidazole to obtain bactericidal surface

    NASA Astrophysics Data System (ADS)

    Meléndez-Ortiz, H. Iván; Alvarez-Lorenzo, Carmen; Concheiro, Angel; Jiménez-Páez, Víctor M.; Bucio, Emilio

    2016-02-01

    N-vinylimidazole (VIm) was grafted onto medical-grade poly(vinyl chloride) (PVC) catheters in order to provide a bactericidal surface that make them less susceptible to microbial colonization. The grafting of VIm was carried out by means of gamma rays using the direct method, which demonstrated to be an efficient and fast procedure for obtaining PVC-g-VIm copolymers. These copolymers could be quaternized in a second step using methyl iodide (CH3I). The effects of solvent nature, absorbed dose, and monomer concentration on the grafting yield were investigated. Modified PVC catheters were characterized by means of Fourier transform infrared spectroscopy (FT-IR), thermogravimetry (TGA), and swelling studies. PVC-g-VIm copolymers both before and after quaternization showed good hemocompatibility, while quaternization was required to inhibit the growth of Staphylococcus aureus.

  13. [Improvement of PVC bio-carrier surface property by remote plasma].

    PubMed

    Li, Ru; Chen, Jie-Rong; Chen, Jun; Yao, Xin

    2006-01-01

    The effects of various remote plasma, such as Ar, He, O2 and N2 on PVC bio-carrier surface modification were studied. The surface properties were characterized by the contact angle measurement and X-ray photoelectron spectroscopy (XPS). The role of all kinds of active species such as electrons, ions and free radicals involved in plasma surface modification were evaluated. Results show that the remote plasma treatments modify the PVC surface in both wettability and composition, the (O + N)/C of PVC surface increases from 7% to 22%, and the water contact angle decreases from 97 degrees to 15 degrees. The optimal results was achieved when plasma treatment parameters were set, that is treatment time 3 min, Ar flux at 20 cm3/s, power at 60W, sample position of 40 cm. The results show that the modified PVC Bio-carrier adhesion rate and capacity on the modified surface are greatly increased.

  14. EPA announces additional groundwater investigation at Delaware City PVC Superfund site

    EPA Pesticide Factsheets

    PHILADELPHIA (Oct. 15, 2015) - The U.S. Environmental Protection Agency today announced a new investigation to determine the nature and extent of groundwater contamination at the Delaware City PVC Superfund site in New Castle County.

  15. Photostabilizing Efficiency of PVC in the Presence of Schiff Bases as Photostabilizers.

    PubMed

    Yousif, Emad; Al-Amiery, Ahmed A; Kadihum, Abdulhadi; Kadhum, Abdul Amir H; Mohamad, Abu Bakar

    2015-11-04

    The photostabilization of polyvinyl chloride (PVC) films by Schiff bases was investigated. Polyvinyl chloride films containing 0.5 wt % Schiff bases were produced using the same casting method as that used for additive-free PVC films from tetrahydrofuran (THF) solvent. The photostabilization activities of these compounds were determined by monitoring the carbonyl, polyene and hydroxyl indices with irradiation time. The changes in viscosity average molecular weight of PVC with irradiation time were also monitored using THF as a solvent. The quantum yield of chain scission (Φcs) for the studied complexes in PVC was estimated to range between 4.72 and 8.99 × 10(-8). According to the experimental results, several mechanisms were suggested, depending on the structure of the additive. Ultra violet (UV) absorption, peroxide decomposition and radical scavenging were suggested as the photostabilizing mechanisms.

  16. Investigation on the mechanical and physical properties of TPU/PVC blend as potential material of bedpan

    NASA Astrophysics Data System (ADS)

    Hakim, M. I.; Shahnaz, S. S. B.; Luqman, M.; Anis, N. I.; Shuhaida, Y.; Zaharah, S. A.; Baidi, M. B.; Yu, C. W.; Kathiresan, V. S.

    2016-06-01

    The purpose of this study is to determine the impact properties, chemical resistance and morphology of TPU/PVC blend in order to be used as potential material to fabricate bedpan. TPU and incorporation of PVC in TPU was done by melt-mixing method. The blends of TPU/PVC from melt mixing were then undergoing hot press compression moulding to produce sample with 3mm thickness. The blend sample was subjected to drop weight impact test, chemical resistance test and SEM test. Results from impact test showed that 30/70 TPU/PVC has recorded the maximum velocity impacted by 6 J of 1.8 m/s at 97ms while 50/50 TPU/PVC has the highest force (impact strength) of 0.95kN compared with other samples. The result also found that 50/50 TPU/PVC blend has lowest weight change, indicated that the blend has good resistance toward NaOH. HCl has a stronger effect on TPU/PVC blend compared to NaOH for all blend composition where 10/90 TPU/PVC showed highest resistance towards HCl. The micrograph shows that 50/50 TPU/PVC exhibited both smooth surface, indicating the brittleness of PVC and rough and the plasticity fractured surface, indicating the ductility of TPU features.

  17. Study on the recycling of waste PVC compounds from electrical wires

    NASA Astrophysics Data System (ADS)

    Roman, Celso, Jr.; Zattera, Ademir José

    2014-05-01

    The good mechanical, thermal and electrical properties of poly (vinyl chloride) (PVC) make it a polymer used in many applications, among which is the coating of wires and cables. The processing of PVC for this application is made using the extrusion process. The PVC waste resulting from extrusion can be recycled or placed on landfills. The objective of this work is to develop recycling methods to decrease the amount of PVC stored in landfills. This work evaluated the influence of successive processing of PVC on the final properties of the obtained compound, which will be used in the process of coating wire and cable by extrusion. The mechanical properties of the electrical wires were assessed according to the Brazilian Association of Technical Standards (ABNT NBR 6251). Tests of tensile strength, elongation at break, before and after thermal aging in an oven with air circulation for a period of 168 hours at 100 °C were performed. The degradation of the PVC compound was carried out through Fourier transform infrared spectroscopy (FTIR) and mechanical properties evaluation. The results showed that the compound can be reprocessed five times keeping the minimum requirements of the ABNT NBR 6251 Standard. Reprocessing was stopped upon color changing (yellowing) of the compound. Yellowing is a characteristic degradation behavior by dehydrochlorination of PVC. FTIR analysis showed changes at 1600 cm-1, 1430 cm-1, 685 cm-1 and 614 cm-1 bands. The performance of the PVC compound for coating electrical wire and cable was fair, meeting the requirements of the ABNT NBR 6251 Standard even after five reprocessing cycles.

  18. Study on the recycling of waste PVC compounds from electrical wires

    SciTech Connect

    Roman Jr, Celso Zattera, Ademir José

    2014-05-15

    The good mechanical, thermal and electrical properties of poly (vinyl chloride) (PVC) make it a polymer used in many applications, among which is the coating of wires and cables. The processing of PVC for this application is made using the extrusion process. The PVC waste resulting from extrusion can be recycled or placed on landfills. The objective of this work is to develop recycling methods to decrease the amount of PVC stored in landfills. This work evaluated the influence of successive processing of PVC on the final properties of the obtained compound, which will be used in the process of coating wire and cable by extrusion. The mechanical properties of the electrical wires were assessed according to the Brazilian Association of Technical Standards (ABNT NBR 6251). Tests of tensile strength, elongation at break, before and after thermal aging in an oven with air circulation for a period of 168 hours at 100 °C were performed. The degradation of the PVC compound was carried out through Fourier transform infrared spectroscopy (FTIR) and mechanical properties evaluation. The results showed that the compound can be reprocessed five times keeping the minimum requirements of the ABNT NBR 6251 Standard. Reprocessing was stopped upon color changing (yellowing) of the compound. Yellowing is a characteristic degradation behavior by dehydrochlorination of PVC. FTIR analysis showed changes at 1600 cm{sup −1}, 1430 cm{sup −1}, 685 cm{sup −1} and 614 cm{sup −1} bands. The performance of the PVC compound for coating electrical wire and cable was fair, meeting the requirements of the ABNT NBR 6251 Standard even after five reprocessing cycles.

  19. Comparison of VOC and ammonia emissions from individual PVC materials, adhesives and from complete structures.

    PubMed

    Järnström, H; Saarela, K; Kalliokoski, P; Pasanen, A-L

    2008-04-01

    Emission rates of volatile organic compounds (VOCs) and ammonia measured from six PVC materials and four adhesives in the laboratory were compared to the emission rates measured on site from complete structures. Significantly higher specific emission rates (SERs) were generally measured from the complete structures than from individual materials. There were large differences between different PVC materials in their permeability for VOCs originating from the underlying structure. Glycol ethers and esters from adhesives used in the installation contributed to the emissions from the PVC covered structure. Emissions of 2-ethylhexanol and TXIB (2,2,4-trimethyl-1,3-pentanediol diisobutyrate) were common. High ammonia SERs were measured from single adhesives but their contribution to the emissions from the complete structure did not appear as obvious as for VOCs. The results indicate that three factors affected the VOC emissions from the PVC flooring on a structure: 1) the permeability of the PVC product for VOCs, 2) the VOC emission from the adhesive used, and 3) the VOC emission from the backside of the PVC product.

  20. Tertiary recycling of PVC-containing plastic waste by copyrolysis with cattle manure

    SciTech Connect

    Duangchan, Apinya Samart, Chanatip

    2008-11-15

    The corrosion from pyrolysis of PVC in plastic waste was reduced by copyrolysis of PVC with cattle manure. The optimization of pyrolysis conditions between PVC and cattle manure was studied via a statistical method, the Box-Behnken model. The pyrolysis reaction was operated in a tubular reactor. Heating rate, reaction temperature and the PVC:cattle manure ratio were optimized in the range of 1-5 deg. C/min, 250-450 deg. C and the ratio of 1:1-1:5, respectively. The suitable conditions which provided the highest HCl reduction efficiency were the lowest heating rate of 1 deg. C/min, the highest reaction temperature of 450 deg. C, and the PVC:cattle manure ratio of 1:5, with reliability of more than 90%. The copyrolysis of the mixture of PVC-containing plastic and cattle manure was operated at optimized conditions and the synergistic effect was studied on product yields. The presence of manure decreased the oil yield by about 17%. The distillation fractions of oil at various boiling points from both the presence and absence of manure were comparable. The BTX concentration decreased rapidly when manure was present and the chlorinated hydrocarbon was reduced by 45%. However, the octane number of the gasoline fraction was not affected by manure and was in the range of 99-100.

  1. Effect of Calcium Sulphate Nanoparticles on Fusion, Mechanical and Thermal Behaviour Polyvinyl Chloride (pvc)

    NASA Astrophysics Data System (ADS)

    Patil, C. B.; Shisode, P. S.; Kapadi, U. R.; Hundiwale, D. G.; Mahulikar, P. P.

    Calcium Sulphate [CaSO4] was synthesized by in-situ deposition technique and its nano size (60 to 100 nm) was confirmed by Transmission Electron Microscopy (TEM). Composites of the filler CaSO4 (micro and nano) and the matrix poly (vinyl chloride) (PVC) were prepared with different filler loading (0-5 wt. %) by melt mixing. The Brabender torque rheometer equipped with an internal mixer was used for preparation and evaluation of fusion behaviour of composites of different formulations. The effect of nano and micro-CaSO4 content on the structure and properties of composites was studied. The nanostructures and dispersion were studied by wide angle X-ray diffraction (WAXD) and scanning electron microscopy (SEM). The mechanical and thermal properties of PVC/ micro and nano-CaSO4 composites were characterized using Universal Testing Machine (UTM) and Thermo Gravimetric Analyzer (TGA). From the results of WAXD and SEM the flocculation of CaSO4 nanoparticles were observed on the surfaces of PVC matrix. The thermal analysis results showed that the first thermal degradation onset (T onset) of PVC/nano-CaSO4 composites for 1 wt. % of filler were higher as compared with corresponding microcomposites and pristine PVC. However, the tensile strength was decreasing with increasing filler content while, it shows increment in magnitude at 1 and 2 wt. % of nano-CaSO4 as compared with corresponding micro-CaSO4 as well as pristine PVC.

  2. Surface Hydrophilicity and Functional Group-Driven Iron(III) Hydroxide Nucleation on Organic-Coated Substrates in Aqueous Environments

    NASA Astrophysics Data System (ADS)

    Ray, J.; Lee, B.; Baltrusaitis, J.; Jun, Y.

    2012-12-01

    Homogeneous and heterogeneous iron hydroxide nanoparticle nucleation can occur continuously in both natural and complex aqueous systems. Iron oxide nanoparticles can act as sinks and/or carriers for heavy metal contaminants; therefore, it is important to develop a better understanding of factors affecting their formation. Organic coatings are ubiquitous in aqueous environments where they can exist on mineral surfaces (e.g., biofilm), as nanoparticle surface coatings (e.g., natural organic matter), or be introduced as coagulants in water treatment systems. These surface coatings could influence the formation of iron oxide nanoparticles and thus, the mobility of aqueous contaminants. Therefore, to better understand the fate and transport of contaminants in complex aqueous environments, we need more accurate information about mechanisms governing heterogeneous and homogeneous nucleation and growth of iron(III) hydroxide nanoparticles in the presence of organic surface coatings. In this work, we used a unique measurement technique allowing for simultaneous small-angle X-ray scattering (SAXS) and grazing incidence (GISAXS) analysis to monitor nanoparticle nucleation in solution and at substrate surfaces. Clean quartz, and polyaspartate- and alginate-coated substrates were chosen as model substrates to represent mineral coatings, engineered organic coatings and natural organic coatings. Polyaspartate was determined to be the most negatively charged substrate and quartz to be the least negatively charged substrate; however, after 2 h of reaction, the total nanoparticle volume calculations—determined from GISAXS—indicate that precipitation of positively-charged iron(III) hydroxide nanoparticles is 10 times higher on the quartz substrate than on the polyaspartate substrate. This implies that electrostatics do not govern iron(III) hydroxide nucleation. Furthermore, homogeneous nucleation approximately 250 μm above the substrate surface was highest in the presence of the

  3. Rheology of PVC Plastisol: Particle Size Distribution and Viscoelastic Properties.

    PubMed

    Nakajima, N.; Harrell, E. R.

    2001-06-01

    Plastisols of poly(vinyl chloride), PVC, are suspensions of fine particles in plasticizer with about 50% resin volume fraction. Typically, the gross particle size ranges from 15 to 0.2 &mgr;m and smaller, where the common practice of spray-drying these resins and subsequent grinding of larger particles dictate the size ranges including agglomerates as well as the primary particles. The plastisol is a pastelike liquid, which may be spread to coat substrates. The coated substrates are heated in an oven to gel and fuse the material for producing uniform, rubbery products. Because the first step of processing is spreading the plastisol on a substrate, rheology at room temperature is obviously important. The material is thixotropic under very low stress. The flow behavior is pseudoplastic and exhibits dilatancy and fracture at high shear rate. This work is concerned with the pseudoplastic behavior but the dynamic mechanical measurements are employed instead of the usual steady-state shear flow measurements. This is because the steady shear may break up agglomerates. The dynamic measurements with small strain-amplitude avoid the break-up of the agglomerates. This is important, because this work is concerned with the effects of the particle size distribution on the material behavior. The frequency dependence of both viscous and elastic behavior is recorded and presented with samples varying in particle size distribution. Copyright 2001 Academic Press.

  4. H-mode inductive coupling plasma for PVC surface treatment

    NASA Astrophysics Data System (ADS)

    Croccolo, F.; Quintini, A.; Barni, R.; Ripamonti, M.; Malgaroli, A.; Riccardi, C.

    2009-08-01

    An inductively coupled plasma machine has been modified to be able to apply working powers in the order of 1 kW, thus switching to the real inductive H-mode. The plasma is generated by applying a 13.56 MHz radio-frequency to a λ/4 antenna outside the plasma chamber in low pressure conditions. The working gas is argon at pressure in the range from 10 to 100 Pa. With this high power source we have been able to perform plasma etching on a poly(vinyl-chloride) (PVC) film. In particular the effect of the plasma is the selective removal of hydrogen and chlorine from the sample surface. The action of the high power plasma on the sample has been proved to be much more effective than that of the low power one. Results similar to those obtained with the low power machine at about 300 W for 120 min, have been obtained with the high power source at about 600 W for 30 min. The superficial generation of a conductive layer of double C=C bonds was obtained. The samples have been investigated by means of ATR spectroscopy, FIB/SEM microscopy and micro-electrical measurements, which revealed the change in charge conductivity.

  5. Reduction of hexavalent chromium collected on PVC filters.

    PubMed

    Shin, Y C; Paik, N W

    2000-01-01

    Chromium exists at various valences, including elemental, trivalent, and hexavalent chromium, and undergoes reduction-oxidation reactions in the environment. Since hexavalent chromium is known as a human carcinogen, it is most important to evaluate the oxidation-reduction characteristics of the hexavalent chromium species. Although hexavalent chromium can be reduced to trivalent state, the detailed information on this in workplace environments is limited. The purpose of this study was to investigate hexavalent chromium reduction in time in various conditions. A pilot chrome plating operation was prepared and operated in a laboratory for this study. There was evidence that the hexavalent chromium was reduced by time after mist generation. The percentage ratio (with 95% confidence intervals in parentheses) of hexavalent chromium to total chromium was almost 100% (99.1 approximately 102.3) immediately after mist generation, and was reduced to 87.4% (84.8 approximately 89.9) at 1 hour and 81.0% (78.3 approximately 83.5) at 2 hours, respectively. Another test indicated that hexavalent chromium collected on PVC filters was also reduced by time after sampling. Hexavalent chromium was reduced to 90.8% (88.2 approximately 93.3) at 2 hours after sampling. It also was found that hexavalent chromium was reduced during storage in air. It is recommended that air samples of hexavalent chromium be protected against reduction during storage.

  6. Economically attractive route for the preparation of high quality magnetic nanoparticles by the thermal decomposition of iron(III) acetylacetonate.

    PubMed

    Effenberger, Fernando B; Couto, Ricardo A; Kiyohara, Pedro K; Machado, Giovanna; Masunaga, Sueli H; Jardim, Renato F; Rossi, Liane M

    2017-03-17

    The thermal decomposition (TD) methods are among the most successful in obtaining magnetic nanoparticles with a high degree of control of size and narrow particle size distribution. Here we investigated the TD of iron(III) acetylacetonate in the presence of oleic acid, oleylamine, and a series of alcohols in order to disclose their role and also investigate economically attractive alternatives for the synthesis of iron oxide nanoparticles without compromising their size and shape control. We have found that some affordable and reasonably less priced alcohols, such as 1,2-octanediol and cyclohexanol, may replace the commonly used and expensive 1,2-hexadecanediol, providing an economically attractive route for the synthesis of high quality magnetic nanoparticles. The relative cost for the preparation of Fe3O4 NPs is reduced to only 21% and 9% of the original cost when using 1,2-octanediol and cyclohexanol, respectively.

  7. Economically attractive route for the preparation of high quality magnetic nanoparticles by the thermal decomposition of iron(III) acetylacetonate

    NASA Astrophysics Data System (ADS)

    Effenberger, Fernando B.; Couto, Ricardo A.; Kiyohara, Pedro K.; Machado, Giovanna; Masunaga, Sueli H.; Jardim, Renato F.; Rossi, Liane M.

    2017-03-01

    The thermal decomposition (TD) methods are among the most successful in obtaining magnetic nanoparticles with a high degree of control of size and narrow particle size distribution. Here we investigated the TD of iron(III) acetylacetonate in the presence of oleic acid, oleylamine, and a series of alcohols in order to disclose their role and also investigate economically attractive alternatives for the synthesis of iron oxide nanoparticles without compromising their size and shape control. We have found that some affordable and reasonably less priced alcohols, such as 1,2-octanediol and cyclohexanol, may replace the commonly used and expensive 1,2-hexadecanediol, providing an economically attractive route for the synthesis of high quality magnetic nanoparticles. The relative cost for the preparation of Fe3O4 NPs is reduced to only 21% and 9% of the original cost when using 1,2-octanediol and cyclohexanol, respectively.

  8. A hexadentate bis(thiosemicarbazonato) ligand: rhenium(V), iron(III) and cobalt(III) complexes.

    PubMed

    Paterson, Brett M; White, Jonathan M; Donnelly, Paul S

    2010-03-21

    A new 1,3-diaminopropane bridged bis(thiosemicarbazone) ligand (H(4)L) has been synthesised. The new hexadentate ligand is capable of forming six coordinate complexes with rhenium(V), iron(III) and cobalt(III). In the case of the iron(III) and cobalt(III) complexes the ligand doubly deprotonates to give the monocations [Fe(III)(H(2)L)](+) and [Co(III)(H(2)L)](+) in which the metal ion is in a distorted octahedral environment. In the rhenium(V) complex the ligand loses four protons by deprotonation of both secondary amine nitrogen atoms to give [Re(V)(L)](+) with the metal ion in a distorted trigonal prismatic coordination environment. [Re(V)(L)](+) represents a rare example of a rhenium(V) complex that does not contain one of the ReO(3+), ReN(2+) or Re(NPh)(2+) cores. The new ligand and metal complexes have been characterised by a combination of NMR spectroscopy, X-ray crystallography, mass spectrometry and microanalysis. The electrochemistry of [Fe(III)(H(2)L)](+), [Co(III)(H(2)L)](+) and [Re(V)(L)](+) has been investigated by cyclic voltammetry with each complex undergoing a single electron reduction event. It is possible to prepare the rhenium(V) complex from ReOCl(3)(PPh(3))(2) or directly from [ReO(4)](-) with the addition of a reductant, which suggests the new ligand may be of interest in the development of rhenium radiopharmaceuticals.

  9. Near infrared reflectance spectroscopy for the fast identification of PVC-based films.

    PubMed

    Laasonen, M; Rantanen, J; Harmia-Pulkkinen, T; Michiels, E; Hiltunen, R; Räsänen, M; Vuorela, H

    2001-07-01

    Near infrared (NIR) reflectance spectroscopy was used to develop a non-destructive and rapid qualitative method for the analysis of plastic films used by the pharmaceutical industry for blistering. Three types of films were investigated: 250 microm PVC [poly(vinyl chloride)] films, 250 microm PVC films coated with 40 g m(-2) of PVDC [poly(vinylidene dichloride)] and 250 microm PVC films coated with 5 g m(-2) of TE (Thermoelast) and 90 g m(-2) of PVDC. Three analyses were carried out using different pre-treatment options and a PLS (partial least squares) algorithm. Each analysis was aimed at identifying one type of film and rejecting all types of false sample (different thickness, colour or layer). True and false samples from four plastics manufacturers were included in the calibration sets in order to obtain robust methods that were suitable regardless of the supplier. Specificity was demonstrated by testing validation sets against the methods. The tests showed 0% of type I (false negative identification) and 1% of type II errors (false positive identification) for the PVC method, 13 and 3%, respectively, for the PVC-PVDC method and no error for the PVC-TE-PVDC method. Type II errors, mostly due to the slight sensitivity of the methods to film thickness, are easily corrected by simple thickness measurements. This study demonstrates that NIR spectroscopy is an excellent tool for the identification of PVC-based films. The three methods can be used by the pharmaceutical industry or plastics manufacturers for the quality control of films used in blister packaging.

  10. Greater fibroblast proliferation on an ultrasonicated ZnO/PVC nanocomposite material.

    PubMed

    Maschhoff, Paul M; Geilich, Benjamin M; Webster, Thomas J

    2014-01-01

    There has been a significant and growing concern over nosocomial medical device infections. Previous studies have demonstrated that embedding nanoparticles alone (specifically, zinc oxide [ZnO]) in conventional polymers (eg, polyvinyl chloride [PVC]) can decrease bacteria growth and may have the potential to prevent or disrupt bacterial processes that lead to infection. However, little to no studies have been conducted to determine mammalian cell functions on such a nanocomposite material. Clearly, for certain medical device applications, maintaining healthy mammalian cell functions while decreasing bacteria growth is imperative (yet uncommon). For this reason, in the presented study, ZnO nanoparticles of varying sizes (from 10 nm to >200 nm in diameter) and functionalization (including no functionalization to doping with aluminum oxide and functionalizing with a silane coupling agent KH550) were incorporated into PVC either with or without ultrasonication. Results of this study provided the first evidence of greater fibroblast density after 18 hours of culture on the smallest ZnO nanoparticle incorporated PVC samples with dispersion aided by ultrasonication. Specifically, the greatest amount of fibroblast proliferation was measured on ZnO nanoparticles functionalized with a silane coupling agent KH550; this sample exhibited the greatest dispersion of ZnO nanoparticles. Water droplet tests showed a general trend of decreased hydrophilicity when adding any of the ZnO nanoparticles to PVC, but an increase in hydrophilicity (albeit still below controls or pure PVC) when using ultrasonication to increase ZnO nanoparticle dispersion. Future studies will have to correlate this change in wettability to initial protein adsorption events that may explain fibroblast behavior. Mechanical tests also provided evidence of the ability to tailor mechanical properties of the ZnO/PVC nanocomposites through the use of the different ZnO nanoparticles. Coupled with previous

  11. Preparation and characterization of a sulindac sensor based on PVC/TOA-SUL membrane.

    PubMed

    Lenik, Joanna

    2014-04-01

    A potentiometric sulindac sensitive sensor based on tetraoctylammonium (Z)-5-fluoro-2-methyl-1-[[p-(methylsulfinyl)phenyl]methylene]-1H-indene-3-acetate (TOA-SUL) was described. The electrode responded with sensitivity of 57.5±1.6mV decade(-1) over the linear range 5×10(-5)-1×10(-2)mol L(-1) at pH6.0-9.0. It had the limit of detection 1.4×10(-5)mol L(-1), a fast response time of 13s and showed clear discrimination of sulindac ions from several inorganic and organic compounds and also amino acids. This electrode did not contain any inner solutions, so it was easy and comfortable to use. The proposed sensor was used to determine sulindac in clear solution and in urine sample solution.

  12. Dysprosium selective potentiometric membrane sensor.

    PubMed

    Zamani, Hassan Ali; Faridbod, Farnoush; Ganjali, Mohammad Reza

    2013-03-01

    A novel Dy(III) ion-selective PVC membrane sensor was made using a new synthesized organic compound, 3,4-diamino-N'-((pyridin-2-yl)methylene)benzohydrazide (L) as an excellent sensing element. The electrode showed a Nernstian slope of 19.8 ± 0.6 mV per decade in a wide concentration range of 1.0 × 10(-6)-1.0 × 10(-2) mol L(-1), a detection limit of 5.5 × 10(-7) mol L(-1), a short conditioning time, a fast response time (<10s), and high selectivity towards Dy(III) ion in contrast to other cations. The proposed sensor was successfully used as an indicator electrode in the potentiometric titration of Dy(III) ions with EDTA. The membrane sensor was also applied to the F(-) ion indirect determination of some mouth washing solutions and to the Dy(3+) determination in binary mixtures.

  13. A Computational Study of the Factors Influencing the PVC-Triggering Ability of a Cluster of Early Afterdepolarization-Capable Myocytes.

    PubMed

    Zimik, Soling; Nayak, Alok Ranjan; Pandit, Rahul

    2015-01-01

    Premature ventricular complexes (PVCs), which are abnormal impulse propagations in cardiac tissue, can develop because of various reasons including early afterdepolarizations (EADs). We show how a cluster of EAD-generating cells (EAD clump) can lead to PVCs in a model of cardiac tissue, and also investigate the factors that assist such clumps in triggering PVCs. In particular, we study, through computer simulations, the effects of the following factors on the PVC-triggering ability of an EAD clump: (1) the repolarization reserve (RR) of the EAD cells; (2) the size of the EAD clump; (3) the coupling strength between the EAD cells in the clump; and (4) the presence of fibroblasts in the EAD clump. We find that, although a low value of RR is necessary to generate EADs and hence PVCs, a very low value of RR leads to low-amplitude EAD oscillations that decay with time and do not lead to PVCs. We demonstrate that a certain threshold size of the EAD clump, or a reduction in the coupling strength between the EAD cells, in the clump, is required to trigger PVCs. We illustrate how randomly distributed inexcitable obstacles, which we use to model collagen deposits, affect PVC-triggering by an EAD clump. We show that the gap-junctional coupling of fibroblasts with myocytes can either assist or impede the PVC-triggering ability of an EAD clump, depending on the resting membrane potential of the fibroblasts and the coupling strength between the myocyte and fibroblasts. We also find that the triggering of PVCs by an EAD clump depends sensitively on factors like the pacing cycle length and the distribution pattern of the fibroblasts.

  14. A Computational Study of the Factors Influencing the PVC-Triggering Ability of a Cluster of Early Afterdepolarization-Capable Myocytes

    PubMed Central

    Zimik, Soling; Nayak, Alok Ranjan; Pandit, Rahul

    2015-01-01

    Premature ventricular complexes (PVCs), which are abnormal impulse propagations in cardiac tissue, can develop because of various reasons including early afterdepolarizations (EADs). We show how a cluster of EAD-generating cells (EAD clump) can lead to PVCs in a model of cardiac tissue, and also investigate the factors that assist such clumps in triggering PVCs. In particular, we study, through computer simulations, the effects of the following factors on the PVC-triggering ability of an EAD clump: (1) the repolarization reserve (RR) of the EAD cells; (2) the size of the EAD clump; (3) the coupling strength between the EAD cells in the clump; and (4) the presence of fibroblasts in the EAD clump. We find that, although a low value of RR is necessary to generate EADs and hence PVCs, a very low value of RR leads to low-amplitude EAD oscillations that decay with time and do not lead to PVCs. We demonstrate that a certain threshold size of the EAD clump, or a reduction in the coupling strength between the EAD cells, in the clump, is required to trigger PVCs. We illustrate how randomly distributed inexcitable obstacles, which we use to model collagen deposits, affect PVC-triggering by an EAD clump. We show that the gap-junctional coupling of fibroblasts with myocytes can either assist or impede the PVC-triggering ability of an EAD clump, depending on the resting membrane potential of the fibroblasts and the coupling strength between the myocyte and fibroblasts. We also find that the triggering of PVCs by an EAD clump depends sensitively on factors like the pacing cycle length and the distribution pattern of the fibroblasts. PMID:26675670

  15. Cloud point extraction of iron(III) and vanadium(V) using 8-quinolinol derivatives and Triton X-100 and determination of 10(-7)moldm(-3) level iron(III) in riverine water reference by a graphite furnace atomic absorption spectroscopy.

    PubMed

    Ohashi, Akira; Ito, Hiromi; Kanai, Chikako; Imura, Hisanori; Ohashi, Kousaburo

    2005-01-30

    The cloud point extraction behavior of iron(III) and vanadium(V) using 8-quinolinol derivatives (HA) such as 8-quinolinol (HQ), 2-methyl-8-quinolinol (HMQ), 5-butyloxymethyl-8-quinolinol (HO(4)Q), 5-hexyloxymethyl-8-quinolinol (HO(6)Q), and 2-methyl-5-octyloxymethyl-8-quinolinol (HMO(8)Q) and Triton X-100 solution was investigated. Iron(III) was extracted with HA and 4% (v/v) Triton X-100 in the pH range of 1.70-5.44. Above pH 4.0, more than 95% of iron(III) was extracted with HQ, HMQ, and HMO(8)Q. Vanadium(V) was also extracted with HA and 4% (v/v) Triton X-100 in the pH range of 2.07-5.00, and the extractability increased in the following order of HMQ < HQ < HO(4)Q < HO(6)Q. The cloud point extraction was applied to the determination of iron(III) in the riverine water reference by a graphite furnace atomic absorption spectroscopy. When 1.25 x 10(-3)M HMQ and 1% (v/v) Triton X-100 were used, the found values showed a good agreement with the certified ones within the 2% of the R.S.D. Moreover, the effect of an alkyl group on the solubility of 5-alkyloxymethyl-8-quinolinol and 2-methyl-5-alkyloxymethyl-8-quinolinol in 4% (v/v) Triton X-100 at 25 degrees C was also investigated.

  16. Change Spectroscopic, thermal and mechanical studies of PU/PVC blends

    NASA Astrophysics Data System (ADS)

    Hezma, A. M.; Elashmawi, I. S.; Rajeh, A.; Kamal, Mustafa

    2016-08-01

    Blends of polyurethane (PU) and polyvinyl chloride (PVC) with different concentrations were prepared by casting method. The effects of PU on PVC blends was examined by Fourier transform-infrared (FTIR), Ultra-violet visible studies (UV/VIS.), X-ray diffraction (XRD), Thermogravimetric (TGA), Differential scanning calorimetry (DSC), and mechanical properties (stress-strain curve). The interaction between PU and PVC was examined by FT-IR through the absorbance of the N-H groups and was correlated to mechanical/thermal properties. Ultra-violet visible said that optical energy gap decrease with increasing concentration of PU. Differential scanning calorimetry results was observed a single glass transition temperature (Tg) for blends this confirming existence miscibility within the blends. The causes for best thermal stability of some blends may be described by measurements of interactions between C=O groups of PU and the α-hydrogen of PVC or a dipole-dipole -C=O..Cl-C- interactions. Significant alterations in FTIR, X-ray and DSC examination shows an interactions between blends had good miscibility. X-ray shows some alterations in the intensity with additional PU. PU change the mechanical behavior of PVC through of the blends. When polyurethane content increase causes polyvinyl chloride tensile strength decreases and elongation at break increase.

  17. Predicting the migration rate of dialkyl organotins from PVC pipe into water.

    PubMed

    Adams, William A; Xu, Ying; Little, John C; Fristachi, Anthony F; Rice, Glenn E; Impellitteri, Christopher A

    2011-08-15

    Organotins (OTs) are additives widely used as thermal and light stabilizers in polyvinyl chloride (PVC) plastics. OTs can leach into water flowing through PVC pipes. This work examines the leaching rates of two potentially neurotoxic OTs, dimethyl tin (DMT) and dibutyl tin (DBT), from PVC pipe. Water was circulated in a closed loop laboratory PVC pipe system. Using a gas chromatograph-pulsed flame photometric detector (GC-PFPD), the change in concentrations of DMT and DBT in the water in the system was monitored over time and allowed to reach equilibrium. OT concentration as a function of time was analyzed using a mechanistic leaching rate model. The diffusion coefficient for OT in the PVC pipe material, the only unknown model parameter, was found to be 9 × 10(-18) m(2)/s. This value falls within with the range of values estimated from the literature (2 × 10(-18) to 2 × 10(-17) m(2)/s) thus increasing confidence in the leaching rate model.

  18. Materials degradation in PVC medical devices, DEHP leaching and neonatal outcomes.

    PubMed

    Latini, G; Ferri, M; Chiellini, F

    2010-01-01

    Polymeric materials play a key role in the production of medical and clinical devices thanks to their special features such as flexibility, easy processing and good price/performance ratio. Among the different polymeric matrixes, one of the most used is Poly(vinyl chloride) (PVC). At room temperature PVC is hard and brittle, thus great amounts (40-50%) of phthalate esters that act as plasticizers are added to the polymer to make it flexible and appropriate for medical use. Di-(2-ethylhexyl)-phthalate (DEHP) is the most widely used plasticizer in PVC medical devices. However, DEHP is not chemically bound to PVC and migrates from medical devices with time and use. The potential for DEHP to produce adverse effects in humans has been the subject of considerable discussion and debate in the scientific community. In particular, newborns in the new environment have to be considered at particularly increased risk, because of their small body size and the multiple medical device-related to the DEHP exposure. The major factors determining the degree to which DEHP migrates from medical devices are temperature, amount of DEHP in the device, storage time, shaking of the device while in contact with the medical solutions and degree of PVC degradation.

  19. Comparative study of the sorption of clomipramine and viloxazine hydrochlorides in Stedim 6 and PVC bags.

    PubMed

    Airaudo, C B; Gayte-Sorbier, A; Bianchi, C

    1998-01-01

    The stability of two antidepressant drugs, clomipramine and viloxazine hydrochlorides, was studied as was their possible sorption on Stedim 6, a new multilayer polyethylene-lined film, which was considered comparatively to polyvinyl chloride (PVC) and glass surfaces. Appropriate amounts of the drugs were added to 500 ml of 5% dextrose and 0.9% sodium chloride solutions in Stedim 6 and PVC bags, and in glass flasks, in order to obtain the concentrations currently used in clinical practice. All the containers were stored at room temperature in daylight for 72 hours. Samples were taken at various times and evaluated for remaining drug concentrations by UV spectrometry. The two drugs appeared stable under the given conditions. No concentration decrease was observed in glass flasks. Viloxazine hydrochloride showed an excellent compatibility with the PVC bags, but a slight concentration decrease (about 6-7% in 72 hours) was observed for clomipramine hydrochloride, depending on the contact duration. The compatibility of the two drugs with the new material Stedim 6 was found to be perfect. The behavioral differences observed between the two drugs with regard to PVC are explained in terms of differences of lipophilicity of the drugs. Those observed for a given drug with regard to the two materials are due to the crystalline structure of polyethylene and the amorphous one of PVC.

  20. Microwave treatment of electric arc furnace dust with PVC: dielectric characterization and pyrolysis-leaching.

    PubMed

    Al-Harahsheh, Mohammad; Kingman, Sam; Al-Makhadmah, Leema; Hamilton, Ian E

    2014-06-15

    Microwave treatment of electric arc furnace dust (EAFD) with poly(vinyl chloride) (PVC) was studied in this work. A comprehensive characterization of the dust as well as assessing the suitability of using the thermal de-chlorination of the common plastic (PVC) under inert atmosphere was carried out to assess the possibility of Zn and other heavy metals extraction (Pb and Cd) from EAFD. The dielectric and thermal properties of EAFD, PVC and their mixtures were measured. Once combined and heated the metal oxides present in the dust reacted with HCl released from PVC during thermal de-chlorination, forming metal chlorides which were subsequently recovered by leaching with water. It was found that zinc chloride could be almost completely recovered in the leaching stage, with the overall recovery of Zn reaching 97% when the EAFD:PVC ratio was 1:2. The investigation highlighted that franklinite, the most refractory mineral to leaching, was completely destroyed. The leaching residue was found to compose mainly of magnetite and hematite.

  1. Synthesis, antioxidant activities of the nickel(II), iron(III) and oxovanadium(IV) complexes with N2O2 chelating thiosemicarbazones.

    PubMed

    Bal-Demirci, Tülay; Sahin, Musa; Ozyürek, Mustafa; Kondakçı, Esin; Ulküseven, Bahri

    2014-05-21

    The nickel(II), iron(III) and oxovanadium(IV) complexes of the N2O2 chelating thiosemicarbazones were synthesized using 4-hydroxysalicyladehyde-S-methylthiosemicarbazone and R1-substitute-salicylaldehyde (R1: 4-OH, H) in the presence of Ni(II), Fe(III), VO(IV) ions by the template reaction. The structures of the thiosemicarbazone complexes were characterized by FT-IR, (1)H NMR, elemental, ESI-MS and APCI-MS analysis. The synthesized compounds were screened for their antioxidant capacity by using the cupric reducing antioxidant capacity (CUPRAC) method. Trolox equivalent antioxidant capacity (TEAC) of iron(III) complex, 1c, was measured to be higher than that of the other complexes. Other parameters of antioxidant activity (scavenging effects on •OH, O2(•-) and H2O2) of these compounds were also determined. All the compounds have shown encouraging ROS scavenging activities.

  2. 4-Nitrocatecholato iron(III) complexes of 2-aminomethyl pyridine-based bis(phenol) amine as structural models for catechol-bound 3,4-PCD

    NASA Astrophysics Data System (ADS)

    Safaei, Elham; Heidari, Sima; Wojtczak, Andrzej; Cotič, Patricia; Kozakiewicz, Anna

    2016-02-01

    Two nitrocatecholato(HNC) iron(III) complexes, [FeLAMPX(H-NC)]. NEt3, of the tetradendate ligand (2-aminomethylpyridine)bis(2-pyridylmethyl)amine (H2LAMPX) were synthesized and structurally characterized. These structural models for catechol-bound 3,4-PCD were characterized by IR, UV-vis, elemental analysis and magnetic measurements. X-ray crystallography studies revealed that in both complexes the iron(III) centers are distorted octahedral and coordinated by two phenolate oxygen's, two amine nitrogen's of the ligand and mono anionic nitrocatecholate group (HNC). The variable-temperature magnetic susceptibility studies revealed paramagnetic properties of the reported complexes. The effective magnetic moments for the complexes lie between 5.3 and 5.4 BM correspond to the reported values for high spin Fe(III) center. The ligand-centered oxidation and metal-centered reduction of complexes was studies using cyclic voltammetry (CV) technique.

  3. Radon 222 permeation through different polymers (PVC, EVA, PE and PP) after exposure to gamma radiation or surface treatment by cold plasma

    NASA Astrophysics Data System (ADS)

    Klein, D.; Tomasella, E.; Labed, V.; Meunier, C.; Cetier, Ph.; Robé, M. C.; Chambaudet, A.

    1997-08-01

    In order to limit radon emission during the storage of radioactive wastes and to comply with the different regulations in the storage facility, the packaging used for these types of wastes should include intermediate enclosures, such as polymer membranes used as radon barriers. However, the membrane would be subjected to different types of radiation during long periods of storage, it would have to be regularly monitored for damage. The first aim of this study is to check the efficiency and the continuity of such polymer membranes subjected to different accelerated ageing processes by exposure to gamma radiation. PolyVinyl Chloride (PVC) and Ethylene Vinyl Acetate (EVA) membranes were studied after gamma exposures. Thus, we evaluated the effects of the gamma radiations on the radon permeation coefficient, and the degradation of these polymers due to this exposure. The second objective of this study is to evaluate the modifications of the polymer surface by cold plasma. PolyEthylene (PE) and PolyPropylene (PP) membranes were studied. Exposure of a polymer to a plasma creates reactive sites on the polymer's surface. Different modifications in the surface composition (chemical composition, molecular weight, etc.) can be obtained. The advantage of the plasma process is that it acts within seconds and does not produce any noticeable effects on the bulk properties. The obtained results show that this treatment increases the polymer's efficiency as a radon barrier.

  4. Survival of allochthonous bacteria in still mineral water bottled in polyvinyl chloride (PVC) and glass.

    PubMed

    Moreira, L; Agostinho, P; Morais, P V; da Costa, M S

    1994-09-01

    The mortality of Escherichia coli, Enterobacter cloacae, Klebsiella pneumoniae and Pseudomonas aeruginosa, based on the culturability of these bacteria, was assessed in non-carbonated mineral water, bottled in polyvinyl chloride (PVC) containing the indigenous flora, sterile mineral water bottled in PVC, sterile mineral water in glass containers, and sterile tap water in glass containers. There was a general decrease in the culturability of these organisms in the four test waters, except that Ps. aeruginosa grew in sterile tap water. Escherichia coli and Kl. pneumoniae had the highest mortality rates under the conditions tested, while Ent. cloacae had a very low and constant mortality rate that would have resulted in the persistence of this organism in mineral water for a long period of time. After a sharp initial decrease in culturability, Ps. aeruginosa also had a very low mortality rate in mineral water bottled in PVC.

  5. Model fire tests on polyphosphazene rubber and polyvinyl chloride (PVC)/nitrile rubber foams

    NASA Technical Reports Server (NTRS)

    Widenor, W. M.

    1978-01-01

    A video tape record of model room fire tests was shown, comparing polyphosphazene (P-N) rubber and polyvinyl chloride (PVC)/nitrile rubber closed-cell foams as interior finish thermal insulation under conditions directly translatable to an actual fire situation. Flashover did not occur with the P-N foam and only moderate amounts of low density smoke were formed, whereas with the PVC/nitrile foam, flashover occurred quickly and large volumes of high density smoke were emitted. The P-N foam was produced in a pilot plant under carefully controlled conditions. The PVC/nitrile foam was a commercial product. A major phase of the overall program involved fire tests on P-N open-cell foam cushioning.

  6. Lysozyme immobilization onto PVC catheters grafted with NVCL and HEMA for reduction of bacterial adhesion

    NASA Astrophysics Data System (ADS)

    Guadarrama-Zempoalteca, Yesica; Díaz-Gómez, Luis; Meléndez-Ortiz, H. Iván; Concheiro, Angel; Alvarez-Lorenzo, Carmen; Bucio, Emilio

    2016-09-01

    The aim of the present work was to functionalize poly(vinyl chloride) (PVC) urinary catheters with grafted copolymers that can improve the biocompatibility and serve as binding points of lysozyme. PVC catheters were modified by grafting a mixture of N-vinylcaprolactam (NVCL) and 2-hydroxyethylmethacrylate (HEMA) applying a gamma-ray pre-irradiation method. The effect of absorbed dose, monomer concentration, temperature, and reaction time on the grafting percentage was evaluated. The grafted catheters were characterized regarding surface composition (FTIR-ATR spectroscopy), thermal properties (DSC and TGA) and swelling in aqueous medium. Lysozyme was directly coupled onto PVC-g-(NVCL/HEMA) previously activated using carbonyldiimidazole. Antimicrobial lytic activity of the modified catheters over time was tested against Micrococcus lysodeikticus. Lysozyme diminished the adhesion of Staphylococcus aureus onto the functionalized catheters, which may be suitable to prevent biofilm formation.

  7. Impact of the nature and concentration of plasticizers on the ability of PVC to sorb drug.

    PubMed

    Al Salloum, H; Saunier, J; Aymes-Chodur, C; Barakat, H; Yagoubi, N

    2015-12-30

    The sorption of a drug by an infusion set may dramatically reduce the drug delivery efficiency. In this paper, we investigated how the drug sorption, in static conditions, is affected by the plasticizer's nature and ratio in the case of plasticized PVC, one of the most common material for infusion set tubing. Within the study, the drug concentration in diazepam solutions was studied after contact with PVC films containing different amounts of DEHP, DEHT, TOTM and DINCH® plasticizers. Moreover the partition coefficients between material and water were calculated. The drug sorption levels were equivalent for the different plasticizers and there was a plasticizer ratio for which the drug uptake was enhanced. As a consequence, the amount of sorbed drug might not be only linked to the amount of plasticizer in the film and to the solubility of the drug in the plasticizer alone: it must probably depend on specific interactions between plasticizer and PVC.

  8. Hyperbranched poly(epsilon-caprolactone) as a nonmigrating alternative plasticizer for phthalates in flexible PVC.

    PubMed

    Choi, Jeongsoo; Kwak, Seung-Yeop

    2007-05-15

    Hyperbranched (dendritic) poly(epsilon-caprolactone)s (HPCLs) were synthesized to have architectural variations, which are the different lengths of linear segments and different numbers of branches, and were used as plasticizers for flexible poly(vinyl chloride) (PVC). The plasticization efficiency estimated by the lowering of glass transition temperature and the enhancement in ultimate elongation indicated that the HPCLs with the shorter linear segments and the larger number of branches imparted as high flexibility as di(ethylhexyl) phthalate (DEHP) and much higher flexibility than their linear analogue, linear poly(epsilon-caprolactone), which is one of currently used polymer plasticizers. Volatility, extractability, and exudation tests for PVC/HPCL samples showed that there was no plasticizer migration even at very harsh condition, while ca. 7-78% of additives in PVC/DEHP was migrated out of samples, indicating that the HPCL can be used as an alternative plasticizer to remove the potential health risk from migrating phthalates during end use.

  9. The Effect of processing on the PVC/Clay Nanocomposites Structure

    NASA Astrophysics Data System (ADS)

    Kalendova, A.; Zykova, J.; Kovarova, L.; Slouf, M.; Gerard, J. F.

    2010-06-01

    Reported nanocomposites of poly(vinyl chloride) have been prepared using bentonite-based clay, Na-montmorillonite (nature clay) and organophilic clay 30B. Polymer nanocomposites of differing compositions were produced using Buss KO-kneader via melt intercalation method. The effect of different type of plasticizer (both low molecular and high molecular) and compounding conditions on the structure of PVC/clay nanocomposites was investigated. Different compounding conditions were tested to study their influence on nanoparticles dispersion, orientation and exfoliation in PVC/clay nanocomposites. The structure of PVC/MMT nanocomposites was observed using X-ray diffraction, transmission electron microscopy (TEM) and AFM (Atomic Force Microscopy). It was found that the Na-montmorillonite offer low exfoliation level, while 30B modified by plasticizer exhibits fine dispersion of partial to nearly full exfoliated MMT. Moreover the processing conditions play also important role in nanocomposite production.

  10. Surface modification of plasticized PVC by dry cleaning methods: Consequences for artworks

    NASA Astrophysics Data System (ADS)

    Morales Muñoz, C.

    2010-03-01

    A study of dry cleaning methods for plasticized PVC has been undertaken using three commercial cloths recommended for plastics artworks, in addition to cotton swabs traditionally used in art conservation. The evaluation of the cleaning has focussed on the efficiency of the cleaners, and the physical and chemical damages caused by the cleaning. The physical and chemical modifications of the PVC surface have been studied by optical microscopy, non-contact profilometry and ATR-FTIR spectroscopy, while spectrocolorimetry and non-contact profilometry have been used for evaluating the cleaning efficiency. The results have shown that the cleaner's composition and the cleaning time play an important role in damaging the plasticized PVC surface. On the contrary, it has not been completely determined if the texture of the cleaning agents' surface had an influence on the cleaning efficiency.

  11. Study of rigid cross-linked PVC foams with heat resistance.

    PubMed

    Shi, Aihua; Zhang, Guangcheng; Zhao, Chenhui

    2012-12-13

    Three heat resistant cross-linked PVC foam plastics were prepared and their performances were compared with universal cross-linked PVC structural foam. The results show that these three heat resistant foams have higher glass transition temperatures (close to 100 °C) than universal structural foam (83.2 °C). Compared with the universal structural foam, the three heat resistant foams show much higher decomposition temperature and better chemical stability due to the crosslinking of PVC macromolecular chains. The heat distortion temperature (HDT) values of the three heat resistant foam plastics are just a little higher than that of universal structural foam. The three heat resistant foam plastics have good dimensional stability at 140 °C, and when used as core material can closely adhere to the face plates in medium temperature curing processes. Compared with universal structural foam, the three heat resistant foam plastics have slightly better mechanical properties.

  12. Electron spin resonance spectral study of PVC and XLPE insulation materials and their life time analysis

    NASA Astrophysics Data System (ADS)

    Morsy, M. A.; Shwehdi, M. H.

    2006-03-01

    Electron spin resonance (ESR) study is carried out to characterize thermal endurance of insulating materials used in power cable industry. The presented work provides ESR investigation and evaluation of widely used cable insulation materials, namely polyvinyl chloride (PVC) and cross-linked polyethylene (XLPE). The results confirm the fact that PVC is rapidly degrades than XLPE. The study also indicates that colorants and cable's manufacturing processes enhance the thermal resistance of the PVC. It also verifies the powerfulness and the importance of the ESR-testing of insulation materials compared to other tests assumed by International Electrotechnical Commission (IEC) Standard 216-procedure, e.g. weight loss (WL), electric strength (ES) or tensile strength (TS). The estimated thermal endurance parameters by ESR-method show that the other standard methods overestimate these parameters and produce less accurate thermal life time curves of cable insulation materials.

  13. Electron spin resonance spectral study of PVC and XLPE insulation materials and their life time analysis.

    PubMed

    Morsy, M A; Shwehdi, M H

    2006-03-01

    Electron spin resonance (ESR) study is carried out to characterize thermal endurance of insulating materials used in power cable industry. The presented work provides ESR investigation and evaluation of widely used cable insulation materials, namely polyvinyl chloride (PVC) and cross-linked polyethylene (XLPE). The results confirm the fact that PVC is rapidly degrades than XLPE. The study also indicates that colorants and cable's manufacturing processes enhance the thermal resistance of the PVC. It also verifies the powerfulness and the importance of the ESR-testing of insulation materials compared to other tests assumed by International Electrotechnical Commission (IEC) Standard 216-procedure, e.g. weight loss (WL), electric strength (ES) or tensile strength (TS). The estimated thermal endurance parameters by ESR-method show that the other standard methods overestimate these parameters and produce less accurate thermal life time curves of cable insulation materials.

  14. A new iron(III) complex of glycine derivative of amine-chloro substituted phenol ligand: Synthesis, characterization and catechol dioxygenase activity

    NASA Astrophysics Data System (ADS)

    Saberikia, Iraj; Safaei, Elham; Kowsari, Mohammad Hossein; Lee, Yong-Ill; Cotic, Patricia; Bruno, Giuseppe; Rudbari, Hadi Amiri

    2012-12-01

    A new iron(III) complex of the glycine derivative of amine-chloro substituted phenol ligand (H3LGDC) has been prepared and characterized by IR, 1H NMR, UV-Vis spectroscopic techniques, cyclic voltammetry, ESI-MS and magnetic susceptibility studies. X-ray analysis reveals that in iron complex of FeLGDC the iron(III) center has a distorted trigonal bipyramidal coordination sphere and is surrounded by an amine nitrogen, a carboxylate, a water and two phenolate oxygen atoms. The DFT calculations with the UB3LYP/6-311++G** level optimized structure of the complex are in good agreement with experimental X-ray structural data. The variable-temperature magnetic susceptibility indicates that FeLGDC is the paramagnetic high spin iron(III) complex. It has been shown that electrochemical oxidation of this complex is ligand-centered due to the oxidation of phenolate to the phenoxyl radicals. This enzyme mimic utilized molecular oxygen in carrying out the oxidative cleavage of catechols with complete conversion at room temperature.

  15. Effect of tris(3-hydroxy-4-pyridinonate) iron(III) complexes on iron uptake and storage in soybean (Glycine max L.).

    PubMed

    Santos, Carla S; Carvalho, Susana M P; Leite, Andreia; Moniz, Tânia; Roriz, Mariana; Rangel, António O S S; Rangel, Maria; Vasconcelos, Marta W

    2016-09-01

    Iron deficiency chlorosis (IDC) is a serious environmental problem affecting the growth of several crops in the world. The application of synthetic Fe(III) chelates is still one of the most common measures to correct IDC and the search for more effective Fe chelates remains an important issue. Herein, we propose a tris(3-hydroxy-4-pyridinonate) iron(III) complex, Fe(mpp)3, as an IDC corrector. Different morphological, biochemical and molecular parameters were assessed as a first step towards understanding its mode of action, compared with that of the commercial fertilizer FeEDDHA. Plants treated with the pyridinone iron(III) complexes were significantly greener and had increased biomass. The total Fe content was measured using ICP-OES and plants treated with pyridinone complexes accumulated about 50% more Fe than those treated with the commercial chelate. In particular, plants supplied with compound Fe(mpp)3 were able to translocate iron from the roots to the shoots and did not elicit the expression of the Fe-stress related genes FRO2 and IRT1. These results suggest that 3,4-HPO iron(III) chelates could be a potential new class of plant fertilizing agents.

  16. Iron(III) complexes of bis (benzimidazol-2-yl) methyl) thiophene-2,5-dicarboxamide: Synthesis, spectral and oxidation of o-phenylenediamine

    NASA Astrophysics Data System (ADS)

    Tyagi, Nidhi; Mathur, Pavan

    2012-10-01

    Iron(III) complexes of a potentially pentadentate ligand N2, N5-bis ((1H-benzo [d] imidazol-2-yl) methyl) thiophene-2,5-dicarboxamide are synthesized with an exogenous anion X = Cl-, NO3-. Mössbauer and EPR spectroscopy indicates axially distorted complexes. These complexes were utilized for the oxidation of o-phenylenediamine to 2,3-diaminophenazine in presence of H2O2. The initial rate of reaction is dependent on the concentration of o-phenylenediamine as well as the iron(III) complex. Rates of reaction were found to be at least five times higher for the Cl- bound complex. The effect of an added anion like acetate, azide and citrate is found to inhibit the rate of reaction. This suggests that one of the factors affecting the rate determining step is the binding of these anions on a vacant site at the iron(III) centre. The oxidation of o-phenylenediamine to 2,3-diaminophenazine is reminiscent of the functioning of horse radish peroxidase.

  17. Research on the property improvement of PVC using red mud in industrial waste residue

    NASA Astrophysics Data System (ADS)

    Nie, Xiaopeng; Li, Xingang; Shuai, Songxian

    2015-07-01

    Red mud is a red solid power waste that is discharged in the aluminium refinery industry during production. It is a strong alkali and can be categorized as polluting industrial residue. How to make comprehensive use of red mud has become a worldwide issue. In this paper, we put red mud into PVC (polyvinyl chloride polymer), taking advantage of the complicated chemical properties of red mud derived from the Bayer process. The results are compared with silica fume, coal ash and calcium carbonate under the same experimental conditions, which shows that improvement of PVC plastication can be achieved by adding red mud.

  18. Kinetics of thermal de-chlorination of PVC under pyrolytic conditions

    SciTech Connect

    Castro, Alexandra; Soares, Delfim; Vilarinho, Candida; Castro, Fernando

    2012-05-15

    Highlights: Black-Right-Pointing-Pointer Several tests were performed in DTA/TGA for understanding the thermal behavior of pure PVC. Black-Right-Pointing-Pointer We did a kinetic model for the de-chlorination of PVC molecule. Black-Right-Pointing-Pointer A temperature of 340 Degree-Sign C was defined as the optimum temperature for breaking the bond of chlorine in the PVC molecule. Black-Right-Pointing-Pointer The experimental validation of this temperature, led to a removal rate of 99.9% chlorine. - Abstract: Although PVC-containing wastes are an important potential source of energy they are frequently disposed in landfill. In thermal treatment processes such as pyrolysis and gasification, the presence of poly(vinyl chloride) (PVC), a compound with 56.7% of chlorine, may cause problems concerned with environmental protection, as consequence of the formation of hydrochloric acid, chlorine gas and dioxins, as well as corrosion phenomena of the reactor/equipment materials. Thus, a possible solution may involve a previous removal of the chlorine from PVC containing waste through a pyrolysis process at low temperatures before the material being submitted to a subsequent thermal treatment, for energetic valorization. In this work, a kinetic model for the thermal decomposition of PVC has been developed, in view of its de-chlorination. DTA/TGA testing at different temperatures indicated a first order reaction and an activation energy of 133,800 J/mol. An almost completed de-chlorination reaction was obtained at 340 Degree-Sign C under an inert atmosphere. The resulted material is a C{sub n}H{sub n} type polymer with potential to be used in an energy recovery process. Validation test performed at laboratory scale indicate that the temperature of 340 Degree-Sign C enables the removal of {approx}99.9% of the chlorine present in PVC. The chloride can be fixed in the form of an aqueous solution of HCl or calcium chloride, driving to an alternative full process with

  19. Effect of oxygen plasma treatment on surface charge and wettability of PVC blood bag—In vitro assay

    NASA Astrophysics Data System (ADS)

    Khorasani, M. T.; Mirzadeh, H.

    2007-06-01

    Wettability and zeta potential studies were performed to characterize the hydrophobicity and surface charge of PVC blood bag samples and evaluate the effect of these properties on fibroblast cells growth. The surface properties of PVC and plasma treated PVC were compared by water drop contact angle and zeta potential measurement. Light microscopy was used to study the behavior of cell attachment and growth on these surfaces. Water drop contact angle measurement shows that the plasma treated PVC becomes more hydrophilic and wettability increased. Zeta potential and in vitro cell culture measurements noticed that the plasma treated PVC surface is more negatively charge and consequently attachment of the L929 fibroblast cells decreased on this surface.

  20. Photodegradation activity of polyvinyl chloride (PVC)-perchlorinated iron (II) phthalocyanine (FePcCl16) composite film.

    PubMed

    Yang, Changjun; Ye, Liqun; Tian, Lihong; Peng, Tianyou; Deng, Kejian; Zan, Ling

    2011-01-15

    In this paper, a novel kind of photodegradable PVC-FePcCl(16) composite film was prepared by homogeneous embedding FePcCl(16) into the commercial PVC plastic. The photodegradation performance of as-prepared film has been investigated in the ambient air under UV light irradiation by means of weight loss monitoring, FT-IR spectroscopy, UV-Vis spectroscopy. In comparison with the pure PVC film, higher weight loss rate, increasing carbonyl peak intensity and accelerating dehydrochlorination were observed. These results indicate that the PVC-FePcCl(16) composite film has a higher photodegradation activity owing to the FePcCl(16). Moreover, FePcCl(16) has good photostability in the photoreaction. The possible photodegradation mechanism of PVC-FePcCl(16) composite film was also discussed.

  1. Voltammetric heparin-selective electrode based on thin liquid membrane with conducting polymer-modified solid support.

    PubMed

    Guo, Jidong; Amemiya, Shigeru

    2006-10-01

    A novel, solid-supported voltammetric ion-selective electrode to detect anticoagulant/antithrombotic heparin at polarizable poly(vinyl chloride) (PVC) membrane/water interfaces was developed. An approximately 3-4.5-microm-thick PVC membrane plasticized with 2-nitrophenyl octyl ether was supported on a gold electrode modified with a poly(3-octylthiophene) (POT) film as an ion-to-electron transducer. Charge transport through the PVC-covered POT film is electrochemically reversible, as demonstrated by cyclic voltammetry with nonpolarizable membrane/water interfaces. In addition to the fast charge transport, adequate redox capacity of the POT film and a small ohmic potential drop in the thin PVC membrane enable ion transfer voltammetry at polarizable macroscopic membrane/water interfaces in a standard three-electrode cell. Reversible ClO4- transfer at the interfaces coupled with oxidation of a neutral POT film was examined by cyclic voltammetry to determine the distribution of the applied potential to the two polarizable interfaces by convolution technique. Interfacial adsorption and desorption of heparin facilitated by octadecyltrimethylammonium were studied also by cyclic voltammetry and convolution technique to demonstrate that the processes are electrochemically irreversible. Stripping voltammetry based on the interfacial processes gives a low detection limit of 0.005 unit/mL heparin in a saline solution, which is slightly lower than the detection limit of most sensitive heparin sensors reported so far (0.01 unit/mL).

  2. Effects of 60 MeV C 5+ ion irradiation on PmT-PVC and p-TSA doped PoT-PVC blends

    NASA Astrophysics Data System (ADS)

    Lakshmi, G. B. V. S.; Siddiqui, Azher M.; Ali, Vazid; Kulriya, Pawan K.; Zulfequar, M.

    2008-04-01

    Poly(m-toluidine) (PmT) and Poly(o-toluidine) (PoT) have been synthesized from derivatives of aniline (m-toluidine), (o-toluidine) monomers by chemical oxidative polymerization method. After polymerization, PoT powder was doped with p-toluene sulphonic acid (p-TSA) and the polymer powders were blended with poly vinyl chloride (PVC) to achieve PmT and p-TSA doped PoT dispersed films. XRD, FTIR and UV-visible studies were carried out to get their structural changes and optical information. These blends were irradiated by 60 MeV C5+ ions with different fluences. Post Irradiation XRD, FTIR and UV-visible spectroscopy were also performed on all films. On p-TSA doped PoT-PVC blends dc-conductivity measurements are also carried out before and after irradiation. The results show structural modifications which lead to changes in optical and electrical properties.

  3. Novel chiral three-dimensional iron(III) compound exhibiting magnetic ordering at T(c) = 40 K.

    PubMed

    Armentano, Donatella; De Munno, Giovanni; Lloret, Francesc; Palii, Andrei V; Julve, Miguel

    2002-04-22

    The preparation and crystal structure determination of the iron(III) compound of formula [(NH(4))(2)[Fe(2)O(ox)(2)Cl(2)].2H(2)O](n) (1) (ox = oxalate dianion) are reported here. Complex 1 crystallizes in the orthorhombic system, space group Fdd2, with a = 14.956(7) A, b = 23.671(9) A, c = 9.026(4) A, and Z = 8. The structure of complex 1 consists of the chiral anionic three-dimensional network [Fe(2)O(ox)(2)Cl(2)](2-) where the iron(III) ions are connected by single oxo and bisbidentate oxalato groups. The metal-metal separations through these bridging ligands are 3.384(2) and 5.496(2) A, respectively. Ammonium cations and crystallization water molecules are located in the helical pseudohexagonal tunnels defined by iron atoms. The longest iron-iron distance in the pseudohexagonal tunnel is 15.778(2) A whereas the shortest one is 8.734(2) A. The iron atoms are hexacoordinated: a terminal chloro ligand and five oxygen atoms, that of the oxo group and four from two cis coordinated oxalate ligands, build a distorted octahedral environment around the metal atom. The Fe-O(oxo) bond distance [1.825(2) A] is significantly shorter than the Fe(III)-O(ox) [average value 2.103(4) A] and Fe(III)-Cl bond distances [2.314(2) A]. Magnetic susceptibility measurements of 1 in the temperature range 2.0-300 K reveal the occurrence of a susceptibility maximum at 195 K and a transition toward a magnetically ordered state in the lower temperature region with T(c) = 40 K. The strong antiferromagnetic coupling through the oxo bridge (J = -46.4 cm(-1), the Hamiltonian being H = -JS(A).S(B)) accounts for the susceptibility maximum whereas a weak spin canting of approximately 0.3 degrees due to the antisymmetric magnetic exchange within the chiral three-dimensional network is responsible for the magnetic ordering. The values of coercive field (H(c)) and remnant magnetization (M(r)) obtained from the hysteresis loop of 1 at 5 K are 4000 G and 0.016 micro(B).

  4. Anion selective membrane. [ion exchange resins and ion exchange membrane electrolytes for electrolytic cells

    NASA Technical Reports Server (NTRS)

    Alexander, S. S.; Geoffroy, R. R.; Hodgdon, R. B.

    1975-01-01

    Experimental anion permselective membranes were prepared and tested for their suitability as cell separators in a chemical redox power storage system being developed at NASA-Lewis Research Center. The goals of long-term (1000 hr) oxidative and thermal stability at 80 C in FeCl3 and CrCl3 electrolytes were met by most of the weak base and strong base amino exchange groups considered in the program. Good stability is exhibited by several of the membrane substrate resins. These are 'styrene' divinylbenzene copolymer and PVC film. At least four membrane systems produce strong flexible films with electrochemical properties (resistivity, cation transfer) superior to those of the 103QZL, the most promising commercial membrane. The physical and chemical properties of the resins are listed.

  5. Selective separation of virgin and post-consumer polymers (PET and PVC) by flotation method

    SciTech Connect

    Burat, Firat; Gueney, Ali; Olgac Kangal, M.

    2009-06-15

    More and more polymer wastes are generated by industry and householders today. Recycling is an important process to reduce the amount of waste resulting from human activities. Currently, recycling technologies use relatively homogeneous polymers because hand-sorting waste is costly. Many promising technologies are being investigated for separating mixed thermoplastics, but they are still uneconomical and unreliable. At present, most waste polymers cause serious environmental problems. Burning polymers for recycling is not practiced since poisonous gases are released during the burning process. Particularly, polyvinyl chloride (PVC) materials among waste polymers generate hazardous HCl gas, dioxins containing Cl, etc., which lead to air pollution and shorten the life of the incinerator. In addition, they make other polymers difficult to recycle. Both polyethylene terephthalate (PET) and PVC have densities of 1.30-1.35 g/cm{sup 3} and cannot be separated using conventional gravity separation techniques. For this reason, polymer recycling needs new techniques. Among these techniques, froth flotation, which is also used in mineral processing, can be useful because of its low cost and simplicity. The main objective of this research is to recycle PET and PVC selectively from post-consumer polymer wastes and virgin polymers by using froth flotation. According to the results, all PVC particles were floated with 98.8% efficiency in virgin polymer separation while PET particles were obtained with 99.7% purity and 57.0% efficiency in post-consumer polymer separation.

  6. Selective separation of virgin and post-consumer polymers (PET and PVC) by flotation method.

    PubMed

    Burat, Firat; Güney, Ali; Olgaç Kangal, M

    2009-06-01

    More and more polymer wastes are generated by industry and householders today. Recycling is an important process to reduce the amount of waste resulting from human activities. Currently, recycling technologies use relatively homogeneous polymers because hand-sorting waste is costly. Many promising technologies are being investigated for separating mixed thermoplastics, but they are still uneconomical and unreliable. At present, most waste polymers cause serious environmental problems. Burning polymers for recycling is not practiced since poisonous gases are released during the burning process. Particularly, polyvinyl chloride (PVC) materials among waste polymers generate hazardous HCl gas, dioxins containing Cl, etc., which lead to air pollution and shorten the life of the incinerator. In addition, they make other polymers difficult to recycle. Both polyethylene terephthalate (PET) and PVC have densities of 1.30-1.35g /cm(3) and cannot be separated using conventional gravity separation techniques. For this reason, polymer recycling needs new techniques. Among these techniques, froth flotation, which is also used in mineral processing, can be useful because of its low cost and simplicity. The main objective of this research is to recycle PET and PVC selectively from post-consumer polymer wastes and virgin polymers by using froth flotation. According to the results, all PVC particles were floated with 98.8% efficiency in virgin polymer separation while PET particles were obtained with 99.7% purity and 57.0% efficiency in post-consumer polymer separation.

  7. Leaching of lead from new unplasticized polyvinyl chloride (uPVC) pipes into drinking water.

    PubMed

    Zhang, Yuanyuan; Lin, Yi-Pin

    2015-06-01

    Unplasticized polyvinyl chloride (uPVC) pipes have been used in the premise plumbing system due to their high strength, long-term durability, and low cost. uPVC pipes, however, may contain lead due to the use of lead compounds as the stabilizer during the manufacturing process. The release of lead from three locally purchased uPVC pipes was investigated in this study. The effects of various water quality parameters including pH value, temperature, and type of disinfectant on the rate of lead release were examined. The elemental mapping obtained using scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX) confirmed the presence of lead on the inner surfaces of the uPVC pipes and their surface lead weight percentages were determined. The leachable lead concentration for each pipe was determined using high strength acidic EDTA solutions (pH 4, EDTA = 100 mg/L). Lead leaching experiments using tap water and reconstituted tape water under static conditions showed that the rate of lead release increased with the decreasing pH value and increasing temperature. In the presence of monochloramine, lead release was faster than that in the presence of free chlorine.

  8. Migration from PVC cling films compared with their field of application.

    PubMed

    Petersen, J H; Lillemark, L; Lund, L

    1997-01-01

    Samples of PVC cling films were taken at importers, wholesalers and retail shops, and their overall migration to the alternative food simulant iso-octane was measured, after establishment of a correlation between overall migration to olive oil at 40 degrees C in 10 days and to iso-octane in 2 h. Results of the migration testing were compared with the recommended and/or actual use of the PVC film and the labelling discussed in relation to the relevant EEC directives on food contact plastics. The correct labelling of plasticized PVC film intended for use in retail packaging is important to avoid the risk of significant consumer intakes of the plasticizer di-(2-ethylhexyl) adipate (DEHA) after the film has been used in contact with fatty foodstuffs. Sixty percent of the films declared for use in contact with fatty foods showed too high overall migration compared with the current interpretation of legislation at the time of sampling. In most instances DEHA made up about 80% of the total amount of plastic constituents migrating to iso-octane. Taking into consideration a specific migration limit of 3 mg DEHA/dm2, 77% of the films used for fatty foodstuff analysed were not acceptable. The migration of DEHA to non-fatty foods defined as the food simulant water was at or below 0.1 mg/dm2 in all PVC-films.

  9. Electromechanical and electro-optical functions of plasticized PVC with colossal dielectric constant

    NASA Astrophysics Data System (ADS)

    Sato, Hiromu; Hirai, Toshihiro

    2013-04-01

    A soft dielectric polymer, plasticized poly(vinyl chloride) (PVC gel), has been known as a characteristic actuator with electrotactic creep deformation. The deformation can be applied for bending and contraction. The mechanism of the deformation has been attributed to the colossal dielectric constant of the gel induced by dc field. The dielectric constant at 1 Hz, jumps from less than10 to thousand times larger value. The huge dielectric constant suggests the gel can have electro-optic function. In this paper, we introduce the gel can bend light direction by applying a dc electric field. The PVC gel can bend light direction depending on the electric field. Detailed feature of the light bending will be introduced and discussed. Bending angle can be controlled by dielectric plasticizer and electric field. The components of the gel, PVC and plasticizer themselves, did not show any effect of electro-optical function like the PVC gel. The same feature can be observed in other polymer, like poly(vinyl alcohol)-dimethyl sulphoxide gel, too.

  10. Quantification of five plasticizers used in PVC tubing through high performance liquid chromatographic-UV detection.

    PubMed

    Radaniel, Tsanta; Genay, Stéphanie; Simon, Nicolas; Feutry, Frédéric; Quagliozzi, Francesca; Barthélémy, Christine; Lecoeur, Marie; Sautou, Valérie; Décaudin, Bertrand; Odou, Pascal

    2014-08-15

    Searching for alternatives to di-(2-ethylhexyl)-phthalate, a plasticizer that has been widely used in the manufacturing of PVC medical devices, has become a major challenge since a European regulation underlined some clinical risks. The aim of this study is to develop an HPLC-UV method to quantify the currently used alternative plasticizers to DEHP. Five plasticizers, acetyl tributyl citrate, di-(2-ethylhexyl)-phthalate, di-(ethylhexyl)-terephthalate, di-isononyl-1,2-cyclohexane-dicarboxylate, and trioctyl trimellitate, were separated on a C8 stationary phase (2.6 μm, 100 mm × 4.6mm) under gradient elution in 13 min. They were detected at 221 nm leading to a quantification threshold from 0.3 to 750 μg/mL as a function of the plasticizer. Within-day and between-day precisions were inferior to 0.9% and 18%, respectively. The assays were validated according to the accuracy profile method. Plasticizers were extracted from PVC-tubing by dissolving PVC in THF then precipitating it in methanol with a yield of over 90% for each plasticizer. This assay could feasibly be used to quantify plasticizers in PVC medical devices.

  11. Analysis of plasticizers in PVC medical devices: Performance comparison of eight analytical methods.

    PubMed

    Bernard, L; Bourdeaux, D; Pereira, B; Azaroual, N; Barthélémy, C; Breysse, C; Chennell, P; Cueff, R; Dine, T; Eljezi, T; Feutry, F; Genay, S; Kambia, N; Lecoeur, M; Masse, M; Odou, P; Radaniel, T; Simon, N; Vaccher, C; Verlhac, C; Yessad, M; Décaudin, B; Sautou, V

    2017-01-01

    A wide variety of medical devices (MDs) used in hospitals are made of flexible plasticized polyvinylchloride (PVC). Different plasticizers are present in variable amounts in the PVC matrix of the devices and can leach out into the infused solutions and may enter into contact with the patients. The ARMED(1) project aims to assess the migration of these plasticizers from medical devices and therefore the level of exposure in patients. For the first task of the project, eight methods were developed to directly detect and quantify the plasticizers in the PVC matrix of the MDs. We compared the overall performances of the analytical methods using standardized and validated criteria in order to provide the scientific community with the guidance and the technical specifications of each method for the intended application. We have shown that routine rapid screening could be performed directly on the MDs using the FTIR technique, with cost-effective analyses. LC techniques may also be used, but with limits and only with individual quantification of the main plasticizers expected in the PVC matrix. GC techniques, especially GC-MS, are both more specific and more sensitive than other techniques. NMR is a robust and specific technique to precisely discriminate all plasticizers in a MD but is limited by its cost and its low ability to detect and quantify plasticizer contamination, e.g. by DEHP. All these results have been confirmed by a real test, called the " blind test " carried out on 10 MD samples.

  12. Irreversible deformation processes in PVC and its short glass fiber reinforced composites

    SciTech Connect

    Yuan, J.Y.

    1985-01-01

    The tensile mechanical behavior of PVC and its short glass fiber reinforced composites under superimposed hydrostatic pressure was studied up to 3 x 10/sup 8/ Pa. For rigid PVC, the brittle-to-ductile transition was observed at a pressure between 1 x 10/sup 7/ Pa and 2 x 10/sup 7/ Pa. This pressure-induced brittle-to-ductile transition was controlled by the competitive microdeformation processes of crazing and shear banding. Deformation in the post-yield region occurred by neck formation and subsequent drawing to produce chain orientation. A strong environmental stress-cracking effect was observed when PVC samples were exposed to the pressure-transmitting fluid, silicone oil. Three types of pressure dependent deformation processes was observed for the short glass fiber reinforced composites of PVC. Type I behavior shows debonding at the interface between fiber and matrix followed by brittle fracture of the matrix. Type II behavior, which was observed for the first time, exhibits a sharp stress drop due to debonding at the interface followed by matrix shear yielding. In Type III behavior, only upper shear yielding of matrix was observed. The transitional behavior from Type I and Type II was controlled by the pressure induced brittle to ductile transition of the matrix, while the Type II-III transition was strongly affected by debonding at the interface.

  13. Construction and demolition waste as a source of PVC for recycling.

    PubMed

    Prestes, Sabrina Moretto Darbello; Mancini, Sandro Donnini; Rodolfo, Antonio; Keiroglo, Raquel Carramillo

    2012-02-01

    Construction and demolition waste can contain considerable amounts of polyvinyl chloride (PVC). This paper describes a study of the recycling of PVC pipes collected from such waste materials. In a sorting facility for the specific disposal of construction and demolition waste, PVC was found to represent one-third of the plastics separated by workers. Pipes were sorted carefully to preclude any possible contamination by poly(ethylene terephthalate) (PET) found in the waste. The material was ground into two distinct particle sizes (final mesh of 12.7 and 8 mm), washed, dried and recycled. The average formulation of the pipes was determined based on ash content tests and used in the fabrication of a similar compound made mainly of virgin PVC. Samples of recycled pipes and of compound based on virgin material were subjected to tensile and impact tests and provided very similar results. These results are a good indication of the application potential of the recycled material and of the fact that longer grinding to obtain finer particles is not necessarily beneficial.

  14. Image Analysis, Microscopic, and Spectrochemical Study of the PVC Dry Blending Process,

    DTIC Science & Technology

    The dry blending process used in the production of electrical grade pvc formulations has been studies using a combination of image analysis , microscopic...by image analysis techniques. Optical and scanning electron microscopy were used to assess morphological differences. Spectrochemical techniques were used to indicate chemical changes.

  15. Characterization of the PVC phenomena in the exhaust of a cyclone dust separator

    NASA Astrophysics Data System (ADS)

    Yazdabadi, P. A.; Griffiths, A. J.; Syred, N.

    1994-06-01

    A laboratory scale cyclone dust separator with swirl numbers varying from 3.043 to 1.790 was used to examine the effects of different downstream pipework configurations, flowrates and swirl numbers upon the size, shape, and position of the precessing vortex core. Also examined was the effect the precessing vortex core had on the reverse flow zone, and the relationship between the two. It was concluded that the reverse flow zone displaced the central vortex core to create the precessing vortex core. The reverse flow zone would then provide feedback for the precessing vortex core, and precess around the central axis about 30 degrees behind the precessing vortex core (P.V.C). The size and position of the P.V.C was effected by changes in Reynolds number, and any additions of downstream systems to the cyclone would also affect the strength of the P.V.C. The P.V.C would squeeze and accelerate the flow through a constriction set up between the outer limits of the core and of the exit diameter wall. Spiral engulfment vortices were produced on the outside of the flow and served as the initial entrainment mechanism for external flow.

  16. Synthesis of AzPhchitosan-bifenthrin-PVC to protect cables against termites.

    PubMed

    Zhang, Lingkun; Cai, Weiwei; Chen, Wu-Ya; Zhang, Li; Hu, Kaikai; Guan, Yan-Qing

    2016-03-30

    The destruction of PVC cables by termites is a continuing and long-standing problem, which can lead to power leakage and power cut. Given the environmental demerits of insecticide overuse, alternative methods of addressing this problem are a highly desirable goal. In this study, we used photo-immobilization to develop a chitosan carrier system to help bifenthrin immobilize on the surface of the PVC substrate. The immobilization was analyzed using nuclear magnetic resonance (NMR), UV absorption, reverse-phase high-performance liquid chromatography (RP-HPLC), Raman absorption spectroscopy, and thermal gravimetric analysis (TGA). The surface structure and biological activity of the embedded and immobilized bifenthrin were examined using scanning electron microscopy (SEM), atomic force microscopy (AFM), and X-ray photon-electron spectroscopy (XPS). Its efficacy was assessed in pest experiments. The results indicate a successful embedding and immobilization of bifenthrin. Furthermore, the chemical bonding network between AzPhchitosan, bifenthrin, and PVC is stable, guaranteeing no environmental release of bifenthrin, and also providing more efficacious protection against termites. The evidence suggests that this photo-immobilization of bifenthrin-embedded chitosan on the surface of PVC substrates is a novel and environmentally friendly technique for termite control. This paper also reports a modification of chitosan with respect to its novel application in environmental protection.

  17. CORRELATION OF THE GLASS TRANSITION TEMPERATURE OF PLASTICIZED PVC USING A LATTICE FLUID MODEL

    EPA Science Inventory

    A model has been developed to describe the composition dependence of the glass transition temperature (Tg) of polyvinyl chloride (PVC) + plasticizer mixtures. The model is based on Sanchez-Lacombe equation of state and the Gibbs-Di Marzio criterion, which states that th...

  18. Enantiopure tetranuclear iron(III) complexes using chiral reduced Schiff base ligands: synthesis, structure, spectroscopy, magnetic properties, and DFT studies.

    PubMed

    Singh, Reena; Banerjee, Atanu; Colacio, Enrique; Rajak, Kajal Krishna

    2009-06-01

    Four new tetranuclear iron(III) complexes of formula [{Fe(L)(2)}(3)Fe], 1-4, have been prepared by reacting [Fe(ClO(4))(3)].6H(2)O with H(2)L in methanol. Here, L(2-) is the deprotonated form of N-(2-hyrdoxybenzyl)-l-valinol (H(2)L(1)), N-(2-hyrdoxybenzyl)-l-leucinol (H(2)L(2)), N-(5-chloro-2-hyrdoxybenzyl)-l-leucinol (H(2)L(3)), and N-(2-hyrdoxybenzyl)-l-phenylalaninol (H(2)L(4)). The complexes are prepared in an enantiomeric pure form. The complexes have been characterized with the help of IR, UV-vis, circular dichroism (CD), (1)H, and elemental analyses. The complex [{Fe(L(2))(2)}(3)Fe].CH(3)OH.2H(2)O, 2.CH(3)OH.2H(2)O, crystallizes in enantiomeric pure form containing a propeller-like Fe(4)O(6) core. (1)H and CD spectral studies of the four species are consistent with the structural similarities of the complexes in solution. Variable-temperature magnetic susceptibility of one case shows an intramolecular antiferromagnetic coupling between the Fe(III) ions. Magnetic measurements are in accord with the S = 5 ground state and suggest single molecular magnet behavior. The magnetic exchange coupling constant between the iron centers within the molecule is interpreted using broken-symmetry density functional theory calculation.

  19. UHV deposition and characterization of a mononuclear iron(III) β-diketonate complex on Au(111)

    PubMed Central

    Cimatti, Irene; Ninova, Silviya; Lanzilotto, Valeria; Malavolti, Luigi; Rigamonti, Luca; Cortigiani, Brunetto; Mannini, Matteo; Magnano, Elena; Bondino, Federica; Totti, Federico; Cornia, Andrea

    2014-01-01

    Summary The adsorption of the sterically hindered β-diketonate complex Fe(dpm)3, where Hdpm = dipivaloylmethane, on Au(111) was investigated by ultraviolet photoelectron spectroscopy (UPS) and scanning tunnelling microscopy (STM). The high volatility of the molecule limited the growth of the film to a few monolayers. While UPS evidenced the presence of the β-diketonate ligands on the surface, the integrity of the molecule on the surface could not be assessed. The low temperature STM images were more informative and at submonolayer coverage they showed the presence of regular domains characterized by a flat morphology and height of ≈0.3 nm. Along with these domains, tetra-lobed features adsorbed on the kinks of the herringbone were also observed. DFT-simulated images of the pristine molecule and its possible decomposition products allowed to assess the partial fragmentation of Fe(dpm)3 upon adsorption on the Au(111) surface. Structural features with intact molecules were only observed for the saturation coverage. An ex situ prepared thick film of the complex was also investigated by X-ray magnetic circular dichroism (XMCD) and features typical of high-spin iron(III) in octahedral environment were observed. PMID:25551042

  20. UV-Visible Spectroscopy Detection of Iron(III) Ion on Modified Gold Nanoparticles With a Hydroxamic Acid

    NASA Astrophysics Data System (ADS)

    Karami, C.; Alizadeh, A.; Taher, M. A.; Hamidi, Z.; Bahrami, B.

    2016-09-01

    The present work describes the preparation of gold nanoparticles (AuNPs) functionalized with hydroxamic acid and the use of them in UV-visible spectroscopy detection of iron(III) ions. The prepared AuNPs were thoroughly characterized by using UV-visible spectroscopy, TEM, and 1H NMR techniques. The newly synthesized hydroxamic acid-AuNPs are brown in color due to the intense surface plasmon absorption band centered at 527 nm. In the presence of Fe(III), the surface plasmon absorption band is centered at 540 nm. However, the sensitivity of hydroxamic acid-AuNPs towards other metal ions such as Mg(II), Ca(II), Ag(I), Cu(II), Mn(II), Cr(II), Ni(II), Co(II),Fe(II), Hg(II), and Pb(II) can be negligible. This highly selective sensor allows a direct quantitative assay of Fe(III) with a UVvisible spectroscopy detection limited to 45.8 nM.

  1. Separation and preconcentration of iron(II) and iron(III) from natural water on a melamine-formaldehyde resin.

    PubMed

    Filik, H; Oztürk, B D; Doğutan, M; Gümüş, G; Apak, R

    1997-05-01

    A combined method for the preconcentration and selective spectrophotometric determination of both valencies of iron, i.e., Fe(II) and Fe(III), down to 0.4 mug l(-1) has been developed. Iron(III) from synthetic and natural water samples has been concentrated on a melamine-formaldehyde resin at pH 5; iron(II) was not retained under identical conditions. The oxidized iron was concentrated on a second resin column. The iron in both columns was eluted with 1 M HCl solution and separately analyzed by the 1,10-phenanthroline-citrate spectrophotometric method. The effect of pH, adsorption and elution rates, and interferences on the developed procedure were investigated. Metal ions that can be retained by the resin at moderate concentrations, e.g., Al(3+), do not cause interference in more dilute solutions encountered in natural water samples. At least 160-fold volume enrichment can be easily obtained using an adsorption flowrate of 50 ml min(-1). A hydrothermal water sample was analyzed by the recommended procedure and by a literature method, and the results were statistically compared by t- and F-tests.

  2. The effect of priming solutions and storage time on plasticizer migration in different PVC tubing types--implications for wet storage of ECMO systems.

    PubMed

    Horne, David C; Torrance, Ida; Modine, Thomas; Gourlay, Terence

    2009-12-01

    The wet priming of extracorporeal membrane oxygenation systems and storage of these systems for rapid deployment is common practice in many clinical centers. This storage policy is, however, seen by many to be controversial due to the potential adverse effects associated with the migration of the di(2-ethylhexyl) phthalate plasticizer (DEHP) from the polyvinyl chloride (PVC) circuit tubing and issues surrounding the maintenance of sterility. This study was performed to evaluate the effects of both short and long-term storage and priming fluid type on plasticizer migration from four commonly used PVC tubes in extracorporeal membrane oxygenation therapy circuits. The four tubes incorporating three plasticizers, two DEHP, one tri(2-ethylhexyl) trimellitate (TOTM), and one dioctyl adipate (DOA) were exposed to each of the three priming fluids for a period of 28 days. Samples were taken at time intervals of 1, 4, 8, 24, and 48 hours, followed by samples at 7, 14, and 28 days. Each sample was processed using a spectrophotomer and the concentration of plasticizer leaching into each solution at each time-point determined. There was a time dependent increase in plasticizer leached from each tube. The migration was greatly affected by both the priming fluid and tubing type. The migration of DEHP was higher than that of TOTM and DOA over both the short and long-term exposure levels. Plasticizer migration occurs from all of the tubes tested over the long term. The TOTM and DOA tubes performed better than the DEHP counterparts in the short term. Selection of priming fluid has a major bearing on plasticizer migration with significant lipid and protein containing fluids promoting higher migration than simple sodium chloride .9% solution prime. The results suggest that DOA tubing and sodium chloride. 9% solution priming fluid should be selected if wet primed perfusion circuits are to be used over short terms of storage.

  3. The Development of PVC Extrusions for a 14,000 Ton Self-Supporting Structure for the Detection of Neutrinos

    SciTech Connect

    Grudzinski, J. J.; Talaga, R. L.; Pla-Dalmau, A.; Fagan, J. E.; Grozis, C.; Kephart, K.; Fischer, R.

    2014-01-01

    The NOvA Neutrino Experiment has built a one of a kind self-supporting plastic structure, potentially the largest ever built. The PVC structure serves as a neutrino detector and is composed of 28 individual blocks that measure 15.5 m (51 feet) high by 15.5 m (51 feet) wide by 2.1 m (7 feet) deep. The primary parts in the detector construction are 15.5m (51 foot), 15-cell PVC extrusions. These extrusions from the basis of the detector modules which are laminated together in a crossed pattern to form the individual blocks and then filled with mineral oil based liquid scintillator. The self-supporting nature of the detector places important structural requirements on both the PVC formulation and the extrusions. Block assembly requirements impose narrow geometric tolerances. Due to the method of detecting neutrinos, the extrusions must possess exceptionally high reflectivity over a particular wavelength range. The requirement places additional restrictions on the components of the PVC formulation. Altogether, the PVC extrusions have to maintain important reflectivity characteristics, provide structural support to the detector, and meet relatively tight geometric requirements for assembly. In order to meet these constraints, a custom PVC formulation had to be created and extruded. We describe the purpose and requirements of the NOvA detector leading to the production of our unique PVC extrusion, summarize the R&D process, and discuss the lessons learned.

  4. Kinetics of thermal de-chlorination of PVC under pyrolytic conditions.

    PubMed

    Castro, Alexandra; Soares, Delfim; Vilarinho, Cândida; Castro, Fernando

    2012-05-01

    Although PVC-containing wastes are an important potential source of energy they are frequently disposed in landfill. In thermal treatment processes such as pyrolysis and gasification, the presence of poly(vinyl chloride) (PVC), a compound with 56.7% of chlorine, may cause problems concerned with environmental protection, as consequence of the formation of hydrochloric acid, chlorine gas and dioxins, as well as corrosion phenomena of the reactor/equipment materials. Thus, a possible solution may involve a previous removal of the chlorine from PVC containing waste through a pyrolysis process at low temperatures before the material being submitted to a subsequent thermal treatment, for energetic valorization. In this work, a kinetic model for the thermal decomposition of PVC has been developed, in view of its de-chlorination. DTA/TGA testing at different temperatures indicated a first order reaction and an activation energy of 133,800J/mol. An almost completed de-chlorination reaction was obtained at 340°C under an inert atmosphere. The resulted material is a C(n)H(n) type polymer with potential to be used in an energy recovery process. Validation test performed at laboratory scale indicate that the temperature of 340°C enables the removal of ∼99.9% of the chlorine present in PVC. The chloride can be fixed in the form of an aqueous solution of HCl or calcium chloride, driving to an alternative full process with environmental benefits and reduction of the costs associated to the PCV - containing materials/wastes management.

  5. Mercury transformation and distribution across a polyvinyl chloride (PVC) production line in China.

    PubMed

    Ren, Wen; Duan, Lei; Zhu, Zhenwu; Du, Wen; An, Zhongyi; Xu, Lingjun; Zhang, Chi; Zhuo, Yuqun; Chen, Changhe

    2014-02-18

    The production of polyvinyl chloride (PVC) via the calcium carbide process utilizes a catalyst containing large amounts of mercury (Hg) and is therefore one of the most important sources of anthropogenic Hg in China. To measure the emission of Hg from PVC production, we established a flowchart for the calcium carbide process, for which we quantified the Hg content of the material/product at each step. Results indicated that 71.5% of the total Hg (Hg(T)) was lost from the catalyst, most of which was recovered by the Hg remover, accounting for 46.0% of the total Hg (Hg(T)). We determined that 3.7% of the Hg(T) was released into the environment, mostly in solid wastes and byproducts such as hydrochloric acid. Furthermore, no Hg has been detected in the PVC end product. However, we were only able to account for 78.1% of the Hg across the whole system, leaving 21.7% unaccounted for in the mass balance. A rough estimation indicates that most of the "missing" Hg had accumulated in deposits on the inner surface of converters and downstream pipelines; however, the emission to the atmosphere was ≤ 1% of the Hg(T). For a PVC production line equipped with a Hg remover, emissions of Hg to the atmosphere have been estimated to be 4.9 g per tonne PVC. Currently, almost all calcium carbide facilities have been equipped with a Hg remover, which may reduce the release of Hg in China by ∼ 500 t/year.

  6. Analysis of PVC plasticizers in medical devices and infused solutions by GC-MS.

    PubMed

    Bourdeaux, Daniel; Yessaad, Mouloud; Chennell, Philip; Larbre, Virginie; Eljezi, Teuta; Bernard, Lise; Sautou, Valerie

    2016-01-25

    In 2008, di-(2-ethylhexyl) phthalate (DEHP), was categorized as CMR 1B under the CLP regulations and its use in PVC medical devices (MD) was called into question by the European authorities. This resulted in the commercialization of PVC MDs plasticized with the DEHP alternative plasticizers tri-octyl trimellitate (TOTM), di-(2-ethylhexyl) terephthalate (DEHT), di-isononyl cyclohexane-1,2-dicarboxylate (DINCH), di-isononyl phthalate (DINP), di-(2-ethylhexy) adipate (DEHA), and Acetyl tri-n-butyl citrate (ATBC). The data available on the migration of these plasticizers from the MDs are too limited to ensure their safe use. We therefore developed a versatile GC-MS method to identify and quantify both these newly used plasticizers and DEHP in MDs and to assess their migration abilities in simulant solution. The use of cubic calibration curves and the optimization of the analytical method by an experimental plan allowed us to lower the limit of plasticizer quantification. It also allowed wide calibration curves to be established that were adapted to this quantification in MDs during migration tests, irrespective of the amount present, and while maintaining good precision and accuracy. We then tested the developed method on 32 PVC MDs used in our hospital and evaluated the plasticizer release from a PVC MD into a simulant solution during a 24h migration test. The results showed a predominance of TOTM in PVC MDs accompanied by DEHP (<0.1% w/w), DEHT, and sometimes DEHA. The migration tests showed a difference in the migration ability between the plasticizers and a non-linear kinetic release.

  7. Loss of factor VIII activity during storage in PVC containers due to adsorption.

    PubMed

    McLeod, A G; Walker, I R; Zheng, S; Hayward, C P

    2000-03-01

    Recombinant factor VIII concentrates are stable when administered in a reconstituted form according to the manufacturer's specifications, and undiluted via infusion with syringe mini-pumps. However many Haemophilia centres administer recombinant factor VIII further diluted in intravenous fluids for greater ease of administration. To investigate the stability of recombinant factor VIII during administration as a diluted infusion, reconstituted factor VIII was stored in polyvinylchloride (PVC) mini-bags undiluted (146 IU mL-1) and at factor VIII concentrations of 10 IU mL-1 and 2 IU mL-1. After 48 h of storage at room temperature in PVC mini-bags, the recoveries of factor VIII activity were 41.9% of the initial activity for the undiluted (146 IU mL-1) product and 43.7% of the initial activity for factor VIII diluted to 10 IU mL-1. For factor VIII diluted to 2 IU mL-1, the amount of factor VIII activity remaining at 48 h was only 1.8% of the initial activity. In contrast, 100% of factor VIII activity was recovered after 48 h when undiluted reconstituted product (146 IU mL-1) was stored in a syringe. To investigate the mechanism of factor VIII activity loss during storage, factor VIII samples collected after 0, 3 and 48 h of storage were analysed by immunoblotting with factor VIII antibodies. No evidence of factor VIII proteolytic degradation during storage was found, however, large amounts of factor VIII antigen were recovered from the empty PVC mini-bags following elution with denaturing detergent. We conclude that clinically significant losses of factor VIII activity occur during storage in PVC mini-bags and that the loss of activity is most likely due to protein adsorption onto the plastic surface. This loss of factor VIII activity during storage in PVC containers may substantially affect the safety and potential cost savings of administering recombinant factor VIII by continuous infusion.

  8. Polyaspartic acid facilitates oxolation within iron(iii) oxide pre-nucleation clusters and drives the formation of organic-inorganic composites

    NASA Astrophysics Data System (ADS)

    Scheck, J.; Drechsler, M.; Ma, X.; Stöckl, M. T.; Konsek, J.; Schwaderer, J. B.; Stadler, S. M.; De Yoreo, J. J.; Gebauer, D.

    2016-12-01

    The interplay between polymers and inorganic minerals during the formation of solids is crucial for biomineralization and bio-inspired materials, and advanced material properties can be achieved with organic-inorganic composites. By studying the reaction mechanisms, basic questions on organic-inorganic interactions and their role during material formation can be answered, enabling more target-oriented strategies in future synthetic approaches. Here, we present a comprehensive study on the hydrolysis of iron(iii) in the presence of polyaspartic acid. For the basic investigation of the formation mechanism, a titration assay was used, complemented by microscopic techniques. The polymer is shown to promote precipitation in partly hydrolyzed reaction solutions at the very early stages of the reaction by facilitating iron(iii) hydrolysis. In unhydrolyzed solutions, no significant interactions between the polymer and the inorganic solutes can be observed. We demonstrate that the hydrolysis promotion by the polymer can be understood by facilitating oxolation in olation iron(iii) pre-nucleation clusters. We propose that the adsorption of olation pre-nucleation clusters on the polymer chains and the resulting loss in dynamics and increased proximity of the reactants is the key to this effect. The resulting composite material obtained from the hydrolysis in the presence of the polymer was investigated with additional analytical techniques, namely, scanning and transmission electron microscopies, light microscopy, atomic force microscopy, zeta potential measurements, dynamic light scattering, and thermogravimetric analyses. It consists of elastic, polydisperse nanospheres, ca. 50-200 nm in diameter, and aggregates thereof, exhibiting a high polymer and water content.

  9. Effect of microwave heating on the migration of dioctyladipate and acetyltributylcitrate plasticizers from food-grade PVC and PVDC/PVC films into olive oil and water.

    PubMed

    Badeka, A B; Kontominas, M G

    1996-04-01

    Migration of dioctyladipate (DOA) and acetyltributylcitrate (ATBC) plasticizers from plasticized polyvinylchloride (PVC) and polyvinylidene chloride (PVDC)/PVC (Saran) films into both olive oil and distilled water during microwave heating has been studied. The plasticizer migrating into olive oil and water was determined using an indirect GC method after saponification of the ester-type plasticizer (DOA or ATBC) and subsequent collection of the alcohol component of the ester, namely: 2-ethyl-1-hexanol and 1-butanol, respectively. Migration was dependent on heating time, microwave power setting, the nature of the food simulant and the initial concentration of the plasticizer in the film. Migration of DOA into olive oil reached equilibrium after heating for 10 min at full power (604.6 mg DOA/l). Migration into distilled water was 74.1 mg/l after 8 min of microwave cooking at full power. The amount of ATBC migrating into olive oil reached equilibrium after heating for 10 min at full power (73.9 mg ATBC/l). Migration into distilled water was 4.1 mg/l after heating at full power for 8 min. Control samples containing olive oil gave DOA migration values which were significantly higher than the upper limit for global migration (60 mg/l) set by the European Community. It is proposed that PVC should not be used in direct contact with food in the microwave oven, while Saran may be used with caution in microwave heating and reheating applications, avoiding its direct contact with high fat foodstuffs.

  10. Spectrophotometric determination of ferbam [iron(III) dimethyl dithiocarbamate] in commercial sample and wheat grains after extraction of its bathophenanthroline tetraphenylborate complex into molten naphthalene.

    PubMed

    Malik, A K; Rao, A L

    2000-09-01

    A procedure has been developed for the determination of iron(III) dimethyldithiocarbamate by converting it into a iron(III)-bathophenanthroline-tetraphenylborate complex, which was then extracted into molten naphthalene, and the absorbance was measured at 534 nm against a reagent blank. Beer's law is obeyed over the concentration range 0.4-20 microg mL(-)(1) in final solution. The method is sensitive and highly selective and is applied for the determination of ferbam in a commercial sample, in mixtures with various dithiocarbamates (ziram, zineb, maneb, etc.), and from wheat grains.

  11. Direct spectrophotometric determination of ferbam (Iron(III) dimethyldithiocarbamate) in commercial sample and wheat grains using 4,7-diphenyl-1,10-phenanthroline.

    PubMed

    Malik, A K

    2000-12-01

    A procedure has been developed for the determination of iron(III) dimethyldithiocarbamate by converting it into the iron(II)-bathophenanthroline complex, which is then dissolved in acetone-water (1:1), and the absorbance is measured at 534 nm against a reagent blank. Beer's law is obeyed over the concentration range 0.5-20 microg x mL(-1) in the final solution. The method is sensitive and highly selective and is used for the direct determination of ferbam in a commercial sample and in mixtures with various dithiocarbamates (ziram, zineb, maneb, etc.) and from wheat grains.

  12. Membrane stabilizer

    DOEpatents

    Mingenbach, William A.

    1988-01-01

    A device is provided for stabilizing a flexible membrane secured within a frame, wherein a plurality of elongated arms are disposed radially from a central hub which penetrates the membrane, said arms imposing alternately against opposite sides of the membrane, thus warping and tensioning the membrane into a condition of improved stability. The membrane may be an opaque or translucent sheet or other material.

  13. Studying DEHP migration in plasticized PVC used for blood bags by coupling Raman confocal microscopy to UV spectroscopy.

    PubMed

    Al Salloum, H; Saunier, J; Tfayli, A; Yagoubi, N

    2016-04-01

    Plasticized PVC is widely used to make medical devices such as tubing, perfusion bags and blood bags. By using confocal Raman microscopy on a PVC sheet plasticized with around 40% of di-(2-ethylhexyl)phthalate (DEHP), we propose a simple and sensitive approach to studying and understanding the diffusion of plasticizers from polymers into the surrounding media. Moreover, we sought to correlate our findings to standard measurements conducted by UV spectroscopy. This study showed differences in the concentration gradient observed due to the diffusion of the plasticizer inside a PVC sheet. We can thus follow the critical DEHP ratios that can impact the diffusion process. Water and ethanol were chosen as storage media: in ethanol, the lowest concentration of DEHP was observed at the surface resulting in the formation of a less plasticized layer near the interface; unlike ethanol, PVC sheets stored in water showed a greater concentration of DEHP on the film surface as an exudation of DEHP onto the surface.

  14. Spectral response of solvent-cast polyvinyl chloride (PVC) thin film used as a long-term UV dosimeter.

    PubMed

    Amar, Abdurazaq; Parisi, Alfio V

    2013-08-05

    The spectral response of solvent-cast polyvinyl chloride (PVC) thin film suitable for use as a long-term UV dosimeter has been determined by measuring the UV induced change in the 1064 cm(-1) peak intensity of the PVC's infrared (IR) spectra as a function of the wavelength of the incident radiation. Measurements using cut-off filters, narrow band-pass filters and monochromatic radiation showed that the 16 μm PVC film responds mainly to the UVB band. The maximum response was at 290 nm and decreasing exponentially with wavelength up to about 340 nm independent of temperature and exposure dose. The most suitable concentration (W/V%) of PVC/Tetrahydrofuran solution was found to be 10% and the best thickness for the dosimeter was determined as 16 μm.

  15. Structural and transport properties of PVC blend PEG doped with Mg(ClO4)2 solid polymer electrolyte

    NASA Astrophysics Data System (ADS)

    Ramesh, C. H.; Reddy, M. Jaipal; Kumar, J. Siva; Reddy, K. Narasimha

    2014-04-01

    An attempt was made to investigate the effect of Mg(ClO4)2 concentration in PVC-PEG blend polymer electrolyte system. Solid polymer electrolyte films of PVC-PEG-Mg(ClO4)2 have been prepared by using solution - casting process. Structural and transport properties have been studied by employing experimental tools like XRD, FT-IR and DC electrical conductivity. The XRD, FTIR studies were confirmed the formation of a polymer-salt complex. The conductivity results indicated that the incorporation of Mg(ClO4)2 salt into PVC-PEG polymer; at low concentrations the increase in the conductivity is large, but at higher concentrations the increase in conductivity is modest. Using this electrolyte, an electrochemical cells have been fabricated with the configuration Mg/ (PVC-PEG-Mg(ClO4)2) electrolyte / (I2 + C + electrolyte) and its discharge characteristics were determined.

  16. Ferrate(VI)-induced arsenite and arsenate removal by in situ structural incorporation into magnetic iron(III) oxide nanoparticles.

    PubMed

    Prucek, Robert; Tuček, Jiří; Kolařík, Jan; Filip, Jan; Marušák, Zdeněk; Sharma, Virender K; Zbořil, Radek

    2013-04-02

    We report the first example of arsenite and arsenate removal from water by incorporation of arsenic into the structure of nanocrystalline iron(III) oxide. Specifically, we show the capability to trap arsenic into the crystal structure of γ-Fe2O3 nanoparticles that are in situ formed during treatment of arsenic-bearing water with ferrate(VI). In water, decomposition of potassium ferrate(VI) yields nanoparticles having core-shell nanoarchitecture with a γ-Fe2O3 core and a γ-FeOOH shell. High-resolution X-ray photoelectron spectroscopy and in-field (57)Fe Mössbauer spectroscopy give unambiguous evidence that a significant portion of arsenic is embedded in the tetrahedral sites of the γ-Fe2O3 spinel structure. Microscopic observations also demonstrate the principal effect of As doping on crystal growth as reflected by considerably reduced average particle size and narrower size distribution of the "in-situ" sample with the embedded arsenic compared to the "ex-situ" sample with arsenic exclusively sorbed on the iron oxide nanoparticle surface. Generally, presented results highlight ferrate(VI) as one of the most promising candidates for advanced technologies of arsenic treatment mainly due to its environmentally friendly character, in situ applicability for treatment of both arsenites and arsenates, and contrary to all known competitive technologies, firmly bound part of arsenic preventing its leaching back to the environment. Moreover, As-containing γ-Fe2O3 nanoparticles are strongly magnetic allowing their separation from the environment by application of an external magnet.

  17. Ecological risk assessment of on-site soil washing with iron(III) chloride in cadmium-contaminated paddy field.

    PubMed

    Nagai, Takashi; Horio, Takeshi; Yokoyama, Atsushi; Kamiya, Takashi; Takano, Hiroyuki; Makino, Tomoyuki

    2012-06-01

    On-site soil washing with iron(III) chloride reduces Cd levels in soil, and thus the human health risks caused by Cd in food. However, it may threaten aquatic organisms when soil washing effluent is discharged to open aquatic systems. Therefore, we conducted trial-scale on-site soil washing and ecological risk assessment in Nagano and Niigata prefectures, Japan. The ecological effect of effluent water was investigated by two methods. The first was bioassay using standard aquatic test organisms. Twice-diluted effluent water from the Nagano site and the original effluent water from the Niigata site had no significant effects on green algae, water flea, caddisfly, and fish. The safe dilution rates were estimated as 20 times and 10 times for the Nagano and Niigata sites, respectively, considering an assessment factor of 10. The second method was probabilistic effect analysis using chemical analysis and the species sensitivity distribution concept. The mixture effects of CaCl(2), Al, Zn, and Mn were considered by applying a response additive model. The safe dilution rates, assessed for a potentially affected fraction of species of 5%, were 7.1 times and 23.6 times for the Nagano and Niigata sites, respectively. The actual dilution rates of effluent water by river water at the Nagano and Niigata sites were 2200-67,000 times and 1300-110,000 times, respectively. These are much larger than the safe dilution rates derived from the two approaches. Consequently, the ecological risk to aquatic organisms of soil washing is evaluated as being below the concern level.

  18. Reaction mechanism for the highly efficient catalytic decomposition of peroxynitrite by the amphipolar iron(III) corrole 1-Fe.

    PubMed

    Avidan-Shlomovich, Shlomit; Gross, Zeev

    2015-07-21

    The amphipolar iron(III) corrole 1-Fe is one of the most efficient catalysts for the decomposition of peroxynitrite, the toxin involved in numerous diseases. This research focused on the mechanism of that reaction at physiological pH, where peroxynitrite is in equilibrium with its much more reactive conjugated acid, by focusing on the elementary steps involved in the catalytic cycle. Kinetic investigations uncovered the formation of a reaction intermediate in a process that is complete within a few milliseconds (k1 ∼ 3 × 10(7) M(-1) s(-1) at 5 °C, about 7 orders of magnitude larger than the first order rate constant for the non-catalyzed process). Multiple evidence points towards iron-catalyzed homolytic O-O bond cleavage to form nitrogen dioxide and hydroxo- or oxo-iron(iv) corrole. The iron(iv) intermediate was found to decay via multiple pathways that proceed at similar rates (k2 about 10(6) M(-1) s(-1)): reaction with nitrogen dioxide to form nitrate, nitration of the corrole macrocyclic, and dimerization to binuclear iron(iv) corrole. Catalysis in the presence of substrates affects the decay of the iron intermediate by either oxidative nitration (phenolic substrates) or reduction (ascorbate). A large enough excess of ascorbate accelerates the catalytic decomposition of PN by 1-Fe by orders of magnitude, prevents other decay routes of the iron intermediate, and eliminates nitration products as well. This suggests that the beneficial effect of the iron corrole under the reducing conditions present in most biological media might be even larger than in the purely chemical system. The acquired mechanistic insight is of prime importance for the design of optimally acting catalysts for the fast and safe decomposition of reactive oxygen and nitrogen species.

  19. Surfactant-Assisted Nanodrop Spectrophotometer Determination of Iron(III) in a Single Drop of Food, Biological, and Environmental Samples

    NASA Astrophysics Data System (ADS)

    Sharma, A.; Tapadia, K.; Sahin, R.; Shrivas, K.

    2016-01-01

    A surfactant-assisted nanodrop spectrophotometric (NDS) method has been developed for the determination of the iron(III) content in single drops (1 μ L) of food, biological, and or environmental sample using disodium 1-nitroso-2-naphthol-3,6-sulfonate (Nitroso-R salt) as a complexing agent and Tween-80 as non-ionic surfactant at pH 4.0. This method is based on the formation of a complex between the Fe(III) present in a sample and the Nitroso-R-salt in the presence of a surfactant to form a green-colored Fe(III)-Nitroso-R salt complex, which can be measured using a NDS method at a λ max = 710 nm. This system was found to obey Beer's law at concentrations in the range of 50-5000 μ g/L with slope, intercept and correlation coefficient values of 0.683, 0.102, and 0.986, respectively. The molar absorptivity of the complex in terms of the Fe(III) content was determined to be 4.86 × 10 5 L· mol -1 · cm -1 . The detection limit and %RSD values of the method were found to be 17 × 10-3 mg/L and ±1.3706%, respectively. This newly developed method was successfully applied to the determination of the Fe(III) content in single drops of food, biological, and environmental samples, and the results were compared with those obtained by atomic absorption spectrometry.

  20. Unentangled star-shape poly(ε-caprolactone)s as phthalate-free PVC plasticizers designed for non-toxicity and improved migration resistance.

    PubMed

    Choi, Woohyuk; Chung, Jae Woo; Kwak, Seung-Yeop

    2014-07-23

    We develop a nontoxic unentangled star-shape poly(ε-caprolactone) (UESPCL) plasticizer with excellent migration resistance for the production of phthalate-free flexible poly(vinyl chloride) (PVC) by means of the ring-opening polymerization of ε-caprolactone, initiated from the multifunctional core, combined with end-capping, and vacuum purification processes. UESPCL is a transparent liquid at room temperature and exhibits unentangled Newtonian behavior because of its extremely short branched segments. UESPCL is biologically safe without producing an acute toxicity response. Torque analysis measurements reveals that UESPCL offers a faster fusion rate and a higher miscibility with PVC compared to a typical plasticizer, di(2-ethylhexyl) phthalate (DEHP). The solid-state (1)H nuclear magnetic resonance (NMR) spectrum reveals that PVC and UESPCL are miscible with an average domain size of less than 8 nm. The flexibility and transparency of the PVC/UESPCL mixture, that is, phthalate-free flexible PVC, are comparable to the corresponding properties of the PVC/DEHP mixture, and the stretchability and fracture toughness of PVC/UESPCL are superior to the corresponding properties of the PVC/DEHP system. Most of all, PVC/UESPCL shows excellent migration resistance with a weight loss of less than 0.6% in a liquid phase, whereas DEHP migrated out of PVC/DEHP into a liquid phase with a weight loss of about 10%.

  1. Beam Damage of Poly(Vinyl Chloride) [PVC] Film as Observed by X-ray Photoelectron Spectroscopy

    SciTech Connect

    Engelhard, Mark H.; Krishna, Abhilash; Kulkarni, Pranita B.; Lee, Chi-Ying M.; Baer, Donald R.

    2003-03-08

    XPS spectra of a spin-coated film poly(vinyl chloride) (PVC) were collected over a period of 243 minutes at 303 K to determine specimen damage during long exposures to monochromatic Al Ka x-rays. For this PVC film we measured the loss of chlorine as a function of time by rastering a focused 104.6 w 100 um diameter x-ray beam over a 1.4 mm x 0.2 mm area on the sample.

  2. Study on structural, morphological and thermal properties of surface modified polyvinylchloride (PVC) film under air, argon and oxygen discharge plasma

    NASA Astrophysics Data System (ADS)

    Suganya, Arjunan; Shanmugavelayutham, Gurusamy; Serra Rodríguez, Carmen

    2016-09-01

    The effect of air, argon, oxygen DC glow discharge plasma on the polyvinylchloride (PVC) film synthesized by solution casting technique, were evaluated via changes in physio-chemical properties such as structural, morphological, crystalline, thermal properties. The PVC film was plasma treated as a function of exposure time and different plasma forming gases, while other operating parameters such as power and pressure remained constant at 100 W and 2 Pa respectively. The plasma treated PVC were characterized by static contact angle, ATR-FTIR, XPS, AFM and T-peel analysis. It was found that various gaseous plasma treatments have improved the polar components, surface roughness on the surface of PVC which was confirmed by XPS, AFM, resulting in highly enhanced wettability and adhesion. X-ray diffraction study showed that plasma treatment does not persuade considerable change, even though it vaguely induces the crystallinity. The thermal properties of plasma treated PVC were evaluated by Differential Scanning Calorimetry and it was observed that O2 plasma treatment gives higher glass transition temperature of 87.21 °C compared with the untreated one. The glass transition temperature slightly increased for Oxygen plasma treated material due to the presence of higher concentration of the polar functional groups on the PVC surface due to strong intramolecular bonding.

  3. Electroless plating of PVC plastic through new surface modification method applying a semi-IPN hydrogel film

    NASA Astrophysics Data System (ADS)

    Wang, Ming-Qiu; Yan, Jun; Du, Shi-Guo; Li, Hong-Guang

    2013-07-01

    A novel palladium-free surface activation process for electroless nickel plating was developed. This method applied a semi-Interpenetrating Polymer Network (semi-IPN) hydrogel film to modify the poly(vinyl chloride) (PVC) surface by chemical bonds. The activation process involved the formation of semi-IPN hydrogel film on the PVC surface and the immobilization of catalyst for electroless plating linking to the pretreated substrate via Nsbnd Ni chemical bond. The hydrogel layer was used as the chemisorption sites for nickel ions, and the catalyst could initiate the subsequent electroless nickel plating onto the PVC surface. Finally, a Ni-P layer was deposited on the nickel-activated PVC substrate by electroless plating technique. The composition and morphology of nickel-plated PVC foils were characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD). The results of SEM and XRD show that a compact and continuous Ni-P layer with amorphous nickel phase is formed on the PVC surface. EDS shows that the content of the nickel and the phosphorus in the deposits is 89.4 wt.% and 10.6 wt.%, respectively.

  4. A study on organotin levels in Canadian drinking water distributed through PVC pipes.

    PubMed

    Sadiki, A I; Williams, D T

    1999-03-01

    A study on organotin compounds in Canadian drinking water was carried out in winter-spring 1996 (28 sites) and autumn 1996 (21 sites). Approximately 29% and 40% of distribution waters supplied through PVC pipes installed recently (typically less than 6 months) contained organotin compounds in the winter-spring and autumn surveys respectively. Monomethyl-, dimethyl-, monobutyl- and dibutyltin levels ranged up to 291 ng Sn/L, 49.1 ng Sn/L, 28.5 ng Sn/L and 52.3 ng Sn/L, respectively. An additional study in summer 1996, of locations where the highest organotin levels were detected in the winter-spring survey, indicated that organotin levels had decreased in most distribution water samples. Samples of PVC pipe/tubing contained organotin compounds consistent with the organotin patterns found in the distribution water samples.

  5. EFFECT OF THE CLAY MODIFICATION ON THE THERMAL PROPERTIES OF PVC

    SciTech Connect

    Zykova, J.; Kalendova, A.; Kovarova, L.; Malac, J.

    2010-06-02

    The intercalation of organic compound is necessary to functionalize the montmorillonite surface. So, the intercalation of diethylene glycol and polyethylene glycol and the influence of plasticizer, namely tricresyl phosphate and isodecyldiphenyl phosphate as co-intercalating agents were studied. For the PVC/clay nanocomposites the suspension type of PVC was used and the compound was prepared by the melt intercalation method. Two kinds of MMT (Cloisite registered Na{sup +}, Cloisite registered 30B) and laboratory modified MMT by intercalation (diethylene glycol, polyethylene glycol) and co-intercalation (tricresyl phosphate and isodecildifenyl phosphate) agents were used for the set of nanocomposite samples. The thermal stability of nanocomposite specimens was tested using of thermo gravimetric analysis, DMA and pH method.

  6. Adhesion of different bacterial strains to low-temperature plasma treated biomedical PVC catheter surfaces.

    PubMed

    Yousefi Rad, A; Ayhan, H; Kisa, U; Pişkin, E

    1998-01-01

    In this study, firstly five different bacteria (i.e. Coagulase positive and negative staphylococcus, Streptococcus pyogenes, Escherichia coli, Pseudomonas aeruginosa) with their different strains were isolated and used. The contact angle, surface free energy, p-xylene adhesion, and zeta potential of these bacteria were in the range of 43-69 deg, 45.4-61.8 erg cm(-2), 2.3-80.3%, and from -650.2 to + 17.5 mV, respectively. Most of the bacteria were negatively charged. Attachment of these bacteria to PVC catheter and its DMAEMA- and AAc-plasma treated forms were investigated. Bacterial attachment to the hydrophobic PVC catheter was high. Both plasma treatments caused significant drops in bacterial attachment in most of the cases. The effects of AAc-plasma treatment was more significant.

  7. PVC Extrusion Development and Production for the NOvA Neutrino Experiment

    SciTech Connect

    Talaga, R. L.; Grudzinski, J. J.; Phan-Budd, S.; Pla-Dalmau, A.; Fagan, J. E.; Grozis, C.; Kephart, K. M.

    2016-01-05

    We have produced large and highly-reflective open-cell PVC extrusions for the NOvA neutrino oscillation experiment. The extrusions were sealed, instrumented, assembled into self-supporting detector blocks, and filled with liquid scintillator. Each Far Detector block stands 15.7 m high, is 15.7 m wide and 2.1 m thick. More than 22,000 extrusions were produced with high dimensional tolerance and robust mechanical strength. This paper provides an overview of the NOvA Far Detector, describes the preparation of the custom PVC powder, and the making of the extrusions. Quality control was a key element in the production and is described in detail.

  8. Switching of the electrical conductivity of plasticized PVC films under uniaxial pressure

    NASA Astrophysics Data System (ADS)

    Vlasov, D. V.; Apresyan, L. A.; Vlasova, T. V.; Kryshtob, V. I.

    2011-11-01

    The jumplike switching of the electrical conductivity in wide-band-gap polymer (antistatic plasticized polyvinylchloride) films under uniaxial pressure is studied. In various plasticized PVC materials, the uniaxial pressure inducing a conductivity jump by four orders of magnitude or higher changes from several to several hundreds of bars, and this effect is retained at a film thickness of several hundred microns, which is two orders of magnitude larger than the critical film thicknesses known for other wide-band-gap polymers. In addition to the earlier interpretation of the conductivity anomalies in plasticized PVC, we proposed a phenomenological electron-molecular dynamic nanotrap model, in which local charge transfer is provided by mobile molecule segments in a plasticized polymer.

  9. Nonlinear response and two stable electroconducting states in transparent plasticized PVC films

    NASA Astrophysics Data System (ADS)

    Vlasov, D. V.; Apresyan, L. A.; Vlasova, T. V.; Kryshtob, V. I.

    2010-10-01

    The electric conductivity of transparent plasticized poly(vinyl chloride) (PVC) films with thicknesses about 30-50 μm has been studied in electric fields with strengths significantly below the breakdown level. It is established that the PVC films exhibit spontaneous reversible transitions between two stable states—with high and relatively low conductivities, in which the bulk resistivity amounts to ˜103 and 106 Ω m, respectively. Relaxation current-voltage characteristics have been measured in a continuous regime, which allowed the Debye relaxation processes to be taken into consideration and effects related to the nonlinearity and transitions between indicated states to be separated. A regime with deterministic switching between the two conducting states has been observed. A simple qualitative model that describes the anomalous character of conductivity in polymer films is proposed.

  10. PVC-plasticizer DEHP in medical products: do thin coatings really reduce DEHP leaching into blood?

    PubMed

    Hildenbrand, Sibylle L; Lehmann, Hans-Dieter; Wodarz, Roman; Ziemer, Gerhard; Wendel, Hans P

    2005-10-01

    The hemocompatibility of artificial surfaces in extracorporeal blood circulation systems can be improved by coatings. According to the literature, heparin coatings should avoid the leaching of the plasticizer di(2-ethylhexyl) phthalate (DEHP) into the blood from components made from plasticized polyvinyl chloride (PVC). DEHP and its metabolites are known to impair the fertility of male rodents; effects on human fertility are assumed. Three different surface coatings with and without heparin were examined in a Chandler Loop model at 37 degrees C using fresh human blood to evaluate their hemocompatibility and barrier property to plasticizer. The levels of toxic oxidation products of DEHP generated in the blood, particularly, were found as high as in the uncoated tubing. The coatings improved the hemocompatibility, but are not safe protection against the hazardous metabolites of DEHP. For pregnant women, neonates and children, we would recommend using the available surface-coated plasticized PVC tubing sets, but free of DEHP.

  11. Speed of Sound Versus Temperature Using PVC Pipes Open at Both Ends

    NASA Astrophysics Data System (ADS)

    Bacon, Michael E.

    2012-09-01

    In this paper we investigate the speed of sound in air as a function of temperature using a simple and inexpensive apparatus. For this experiment it is essential that the appropriate end corrections be taken into account. In a recent paper the end corrections for 2-in i.d. (5.04-cm) PVC pipes open at both ends were investigated. The air column resonance was excited using a paddle as in Blue Man Group® pipes.2 The "open end" end correction is given by 0.6133r in accordance with recent experiments3 and detailed theoretical calculations.4 This correction amounted to 1.56 cm for the 2-in PVC pipe used. However, the paddle end correction was found to be influenced by the transient position of the paddle during the excitation process. The paddle end correction was found to be 1.94 cm.

  12. Effect of the Clay Modification on the Thermal Properties of Pvc

    NASA Astrophysics Data System (ADS)

    Zykova, J.; Kalendova, A.; Kovarova, L.; Malac, J.

    2010-06-01

    The intercalation of organic compound is necessary to functionalize the montmorillonite surface. So, the intercalation of diethylene glycol and polyethylene glycol and the influence of plasticizer, namely tricresyl phosphate and isodecyldiphenyl phosphate as co-intercalating agents were studied. For the PVC/clay nanocomposites the suspension type of PVC was used and the compound was prepared by the melt intercalation method. Two kinds of MMT (Cloisite®Na+, Cloisite®30B) and laboratory modified MMT by intercalation (diethylene glycol, polyethylene glycol) and co-intercalation (tricresyl phosphate and isodecildifenyl phosphate) agents were used for the set of nanocomposite samples. The thermal stability of nanocomposite specimens was tested using of thermo gravimetric analysis, DMA and pH method.

  13. Comparison of mechanical properties of silicone and PVC (polyvinylchloride) cosmetic gloves for articulating hand prostheses.

    PubMed

    Smit, Gerwin; Plettenburg, Dick H

    2013-01-01

    Current articulating electric and body-powered hands have a lower pinch force (15-34 N) than electric hands with stiff fingers (55-100 N). The cosmetic glove, which covers a hand prosthesis, negatively affects the mechanical efficiency of a prosthesis. The goal of this study is to mechanically compare polyvinylchloride (PVC) and silicone cosmetic gloves and quantify the stiffness of the finger joints, the required actuation energy, and the energy dissipation during joint articulation. Six cosmetic gloves, identical in size but made from different materials, were mechanically tested: three PVC and three silicone. The silicone gloves required less work and dissipated less energy during flexing. They also had a lower joint stiffness and required a lower maximum joint torque. Based on energy requirements, joint stiffness, and required joint torque, the tested silicone glove is most suitable for application on an articulating hand prosthesis.

  14. Effects of short glass fibers on the mechanical properties of glass fiber fabric/PVC composites

    NASA Astrophysics Data System (ADS)

    Park, Su Bin; Lee, Joon Seok; Kim, Jong Won

    2017-03-01

    Fiber-reinforced composites using glass fiber and polyvinylchloride (PVC) have been used widely as architectural materials, electrical applications, automotive sector, and packing materials because of their reasonable price, chemical resistance, and dimensional stability. On the other hand, most of the composites are short fiber-reinforced PVC composites. In particular, in the case of fabric reinforced composites, undulated regions exist where there is only resin due to the characteristics of the weave construction, which causes a decrease in strength. In this paper, PVC was reinforced with chopped glass fibers with different lengths and contents to produce glass fiber fabric/PVC composites. The physical properties of the composites, such as thickness, density, volume fraction (V f), and void content (V c) were identified. The mechanical properties, including tensile strength, flexural strength, and interlaminar shear strength (ILSS) were also identified. A cross section of the composites was observed by scanning electron microscopy. Compared to the fabric reinforced composite without chopped glass fiber, the tensile strength was increased by 3.90% (from 316.15 MPa to 328.48 MPa at 5 wt.% chopped fibers with 3 mm length), flexural strength was increased by 7.15% (from 87.07 MPa to 93.30 MPa at 10 wt.% chopped fibers with 2 mm length), and ILSS was increased by 8.71% (from 7.34 MPa to 7.98 MPa at 10 wt.% chopped fibers with 1 mm length). Therefore, the critical fiber aspect ratio of chopped fiber works differently on each of the three mechanical properties.

  15. Application of electrostatic separation to the recycling of plastic wastes: separation of PVC, PET, and ABS.

    PubMed

    Park, Chul-Hyun; Jeon, Ho-Seok; Yu, Hyo-Shin; Han, Oh-Hyung; Park, Jai-Koo

    2008-01-01

    Plastics are widely used in everyday life as a useful material, and thus their consumption is growing at a rate of about 5% per year in Korea. However, the constant generation of plastic wastes and their disposal generates environmental problems along with economic loss. In particular, mixed waste plastics are difficult to recycle because of their inferior characteristics. A laboratory-scale triboelectrostatic separator unit has been designed and assembled for this study. On the basis of the control of electrostatic charge, the separation of three kinds of mixed plastics, polyvinyl chloride (PVC), poly(ethylene terephthalate) (PET), and acrylonitrile-butadiene-styrene (ABS), in a range of similar gravities has been performed through a two-stage separation process. Polypropylene (PP) and high-impact polystyrene (HIPS) were found to be the most effective materials for a tribo-charger in the separation of PVC, PET, and ABS. The charge-to-mass ratio (nC/g) of plastics increased with increasing air velocity in the tribo charger. In the first stage, using the PP cyclone charger, the separation efficiency of particles considerably depended on the air velocity (10 m/s), the relative humidity (< 30%), the electrode potential (> 20 kV), and the splitter position (+2 cm from the center) in the triboelelctrostatic separator unit. At this time, a PVC grade of 99.40% and a recovery of 98.10% have successfully been achieved. In the second stage, using the HIPS cyclone charger, a PET grade of 97.80% and a recovery of 95.12% could be obtained under conditions of 10 m/s, over 25 kV, a central splitter position, and less than 40% relative humidity. In order to obtain 99.9% PVC grade and 99.3% PET grade, their recoveries should be sacrificed by 20.9% and 27%, respectively, with moving the splitter from the center to a (+)6 cm position.

  16. Surface Properties of Fluorosilicone Copolymers and Their Surface Modification Effects on PVC Film.

    PubMed

    Kim; Lee; Doh

    1998-09-15

    The fluorosilicone copolymers were synthesized using a fluorine-containing monomer and silicone-containing monomers by free-radical random copolymerization, and their surface properties and surface modification ability were investigated. The fluorine-containing monomer used was perfluoroalkyl ethyl acrylate (FA), and the silicone-containing monomers used were 3-[tris(trimethylsilyloxy)silyl]propyl methacrylate (SiMA), vinyltrimethoxy silane (VTMS), and vinyltriethoxy silane (VTES). The surface free energies of the fluorosilicone copolymers prepared were estimated from the contact angle data measured by sessile-drop method. And, the surface free energies of poly(vinyl chloride) (PVC) films modified by the fluorosilicone copolymers were also analyzed using the contact angle data. The fluorosilicone copolymers exhibit the surface free energies of about 8-23 dyn/cm dependent on the molecular weight of the fluorosilicone copolymers. The surface free energies of the fluorosilicone copolymers decrease with increasing molecular weight in the range of 2,000-10,000 (Mw). Among the fluorosilicone copolymers prepared in this study, PFA-r-PSiMA was found to be the most effective as a surface modification agent for PVC film. The inherent surface free energy of PFA-r-PSiMA was estimated to be about 9.0 dyn/cm. The desirable molecular weight of PFA-r-PSiMA seems to be more than 4,000 (Mw). However, it is expected that the fluorosilicone copolymers having the molecular weight of much higher than 10,000 (Mw) may not be suitable as surface modification additives because their compatibility with other polymers will decrease with the molecular weight. The optimum concentration of PFA-r-PSiMA added to PVC film is about 1.0 wt.%. PFA-r-PSiMA is expectedto be an effective additive for surface modification of PVC films. Copyright 1998 Academic Press.

  17. Modification of PVC/ENR blend by electron beam irradiation: effect of crosslinking agents

    NASA Astrophysics Data System (ADS)

    Ratnam, C. T.; Zaman, K.

    1999-05-01

    In order to improve the mechanical properties of PVC/ENR blends, they were irradiated by using a 3.0 MeV electron beam machine with doses ranging from 20 to 200 kGy. Changes in mechanical properties of the blends with increasing irradiation dose were investigated. In an attempt to maximize the beneficial effect of irradiation, the influence of multifunctional acrylates (MFA) such as TMPTA, HDDA and EHA on the 70/30 PVC/ENR blend was investigated. The properties studied include hardness, gel fraction, tensile strength, elongation at break and glass transition temperature. The results revealed that all mechanical properties increased with increasing irradiation dose with exception of elongation at break. The enhancement in blend properties was further improved by addition of MFA. This is attributed to the increase in crosslink density. The steady increase in gel fraction with irradiation dose and the shifting of the irradiation those towards a lower value to achieve 70% gel fraction upon addition of MFA has provided evidence for significant increase in crosslink density. Among the MFA employed in this studies, TMPTA was found to render highest mechanical properties to the blend with irradiation. Thus, TMPTA can be useful as an efficient crosslink enhancer to PVC/ENR blends. Results from Fourier transform infrared spectroscopy (FTIR) indicated radiation-induced crosslinks formed in PVC/ENR blends sensitized by TMPTA. The single glass transition temperature obtained confirms that the blend remains miscible upon irradiation with the presence of TMPTA. The changes in blend properties upon irradiation with the addition of acrylated polyurethene (PU) oligomer are also presented in this paper.

  18. A comparative study of thermal and mechanical stabilities of gamma irradiated PMMA, PP and PVC

    NASA Astrophysics Data System (ADS)

    Güven, O.; Uzun, C.

    1993-10-01

    In this comparative study it has been tried to find a correlation between the thermal and mechanical stabilities of some γ-irradiated polymers. Among various mechanical properties evaluated, the best correlation was found between the toughness (energy to break point) and the time required for 10% weight loss (isothermally). Among three polymers irradiated up to 100 kGy in the form of thin films, the best fit was observed to be for PMMA while PVC and PP has shown poorer correlation.

  19. Speed of Sound versus Temperature Using PVC Pipes Open at Both Ends

    ERIC Educational Resources Information Center

    Bacon, Michael E.

    2012-01-01

    In this paper we investigate the speed of sound in air as a function of temperature using a simple and inexpensive apparatus. For this experiment it is essential that the appropriate end corrections be taken into account. In a recent paper the end corrections for 2-in i.d. (5.04-cm) PVC pipes open at both ends were investigated. The air column…

  20. Tiered environmental risk assessment of methyltins from heat stabilizers in rigid PVC in Sweden.

    PubMed

    van Dokkum, Henno P; Huwer, Sherri L

    2005-02-01

    The methyltins, methyltin 2-ethylhexyl mercaptoacetate and methyltin-2-mercaptoethyloleate sulfide, are used as heat stabilizers in rigid PVC. The degradation products monomethyltintrichloride (MMTTC) and dimethyltindichloride (DMTDC) may leach from the PVC, and enter the environment. A risk assessment was executed for the use of these products in Sweden, with the double aim to (a) assess the potential environmental risks, and (b) explore the possibilities of a tiered risk assessment. An initial assessment was executed with EUSES 1.0. The initial assessment showed no significant environmental risks on a regional scale. On a local scale however, emissions from a sewage treatment plant to the surface water pose a potential risk for the near proximity. In a second tier, this critical exposure route was studied in more detail; an improved exposure scenario was drawn up; and an additional sorption experiment was performed. This refinement resulted in much lower predicted environmental concentrations (PVC in Sweden are of no concern.

  1. γ-Ray modifications of optical/chemical properties of a PVC polymer

    NASA Astrophysics Data System (ADS)

    Gupta, D. P.; Kumar, Shyam; Kalsi, P. C.; Manchanda, V. K.; Mittal, V. K.

    2012-02-01

    Polyvinyl chloride (PVC) films are subjected to high doses of γ -radiation up to 800 kGy. The modifications in the optical properties, the structural and chemical changes are investigated by recording the ultraviolet-visible (UV-VIS) and the Fourier transform infrared (FTIR) spectra of unirradiated and irradiated PVC films. The UV-VIS data show an increase in absorbance and shift of the absorption edge towards the visible region from the UV region with the increase in the γ -radiation dose. This may be attributed to the formation of conjugated system of bonds. The direct and the indirect optical energy band gaps are determined as a function of the γ -exposure dose. The results show that both the direct and the indirect energies of transitions decrease with the increasing γ -absorbed dose. Also the direct energy band gap has higher values when compared with the corresponding values of the indirect energy band gap. The intensity of the different infrared bands in the FTIR spectra of irradiated PVC indicates the presence of the hydroxyl group, release of volatile gases and polyene formation. A total destruction of the structure is observed at a very high γ -radiation dose.

  2. Simple PVC-PPy electrode for pH measurement and titrations.

    PubMed

    Masalles, C; Borrós, S; Viñas, C; Teixidor, F

    2002-02-01

    Cobaltabis(dicarbollide) [3,3'-Co(1,2-C2B9H11)](-)-doped polypyrrole (PPy) films have been prepared galvanostatically on glassy carbon electrodes in acetonitrile solution. The potential response behavior of the film of this new material has been investigated in some common pH buffers and in acid-base titrations. The potentiometric characteristics of the resulting films are indicative of a quasi-Nernstian response (approximately 50 mV/pH unit), a linearity range from pH 12 to 3 and correlation coefficients (r2) of approximately 0.98. The electrode is suitable for pH measurements and for monoprotic titrations of strong alkalis with strong acids, and weak bases with strong acids, but the long response time hinders the use of this electrode for multiprotic titrations. The time response has been dramatically improved by reducing the film thickness by using the template effect of a non-conducting polymer (PVC) cast over the graphite surface before PPy deposition. PPy polymerization occurs in the free channels of PVC leading to the formation of PPy wires. The morphological change of PPy does not affect the slope or linearity range. The response of the PVC-PPy electrochemical sensor is rapid and the sensor is easy to prepare, at low cost, and its performance is comparable with that of commercial glass electrodes.

  3. Diffusion of trichloroethylene through the threaded joints of PVC (polyvinylchloride) pipe

    SciTech Connect

    Jerome, K.M. . Dept. of Civil Engineering)

    1990-12-01

    The data engineers and scientists use to determine if the groundwater supply is contaminated are derived from analysis of samples taken largely from monitoring wells. For these data to be reliable several factors must be considered. One factor is the integrity of the monitoring well. In this project, emphasis has been placed on the potential impact on water quality caused by diffusion across the threaded joints of PVC pipe. In this study, the diffusion of trichloroethylene across several common types of threaded joints (i.e., square flush, modified ACME, modified ACME stub, and ACME) has been measured. Samples were obtained from the water inside the pipe sections and analyzed for trichloroethylene by gas chromatography. Breakthrough occurs within days of the samples being placed in the baths. The softened PVC joints of the pipes in the pure trichloroethylene split before the first sample interval of 1.5 weeks. The data show great variability in casting joints from the same manufacturer, and indicate a need for increased precision in the manufacturing of the PVC pipe joints. A one-dimensional diffusion model is used to determine an equivalent gap size through which the diffusion occurs. Flow rates through the threaded joints are calculated by using the equivalent gap width and a formula for flow through a rectangular duct running full. Comparison of the results of the gap size calculations and of the flow rates is presented. 20 refs., 13 figs. 11 tabs.

  4. Migrability of PVC plasticizers from medical devices into a simulant of infused solutions.

    PubMed

    Bernard, L; Cueff, R; Breysse, C; Décaudin, B; Sautou, V

    2015-05-15

    Medical devices (MD) for infusion and artificial nutrition are essentially made of plasticized PVC. The plasticizers in the PVC matrix can leach out into the infused solutions and may enter into contact with the patients. In order to assess the risk of patient exposure to these plasticizers we evaluated the migration performance of DEHP, DEHT, DINCH, and TOTM using a model adapted to the clinical use of the MDs. Each PVC tubing sample was immersed in a simulant consisting of a mixture of ethanol/water (50/50v/v) at 40°C and migration tests were carried out after 24h, 72h, and 10 days.DEHP had the highest migration ability, which increased over time. The amount of TOTM released was more than 20 times less than that of DEHP, which makes it an interesting alternative. DEHT is also promising, with a migration level three times smaller than DEHP. However, the migration ability of DINCH was similar to DEHP, with the released amounts equaling 1/8th of the initial amount in the tubing after 24h of contact. Taking into account the available toxicological data, TOTM and DEHT appear to be of particular interest. However, these data should be supplemented and correlated with clinical and toxicological studies on plasticizers and their metabolites.

  5. Stabilization of nontoxic PVC formulation for gamma irradiation sterilization, I. Effect of additives.

    PubMed

    Khang, Gilson; Kong, Chong-Su; Rhee, John M; Lee, Hai Bang

    2002-01-01

    In order to investigate the fundamental data for the resistance of gamma radiation sterilization of polyvinylchloride (PVC), the formulations of the additives such as plasticizers of dioctylphthalate, trioctyltrimellitate and polyester, second plasticizers, Ca/Zn nontoxic metallic stabilizers with powder, paste and liquid state, and phosphite stabilizers have been carried out. The control and irradiated PVC samples with 1.5, 2.5 and 4.0 Mrads were characterized by mechanical tester, colorimetry, and extractant in water. The effect of plasticizers observed in the order of dioctylphthalate approximately equal trioctyltrimellitate > polymeric plasticizer. It was observed in the order of Ca/Zn metallic stabilizers of paste > liquid approximately equal powder state for the color change and liquid > paste > powder for the extractant. The mechanism of the discoloration of PVC in our experiment was predominant the formation of polyene by the dehydrochlorination rather than the formation of keton and aldehyde by the oxidation and chain dissociation by the measurement of gel permeation chromatography and mechanical property. The proposed mechanisms of stabilization and discolorization with various additives are also discussed.

  6. Migration of plasticizers from PVC medical devices: Development of an infusion model.

    PubMed

    Bernard, L; Cueff, R; Chagnon, Mc; Abdoulouhab, F; Décaudin, B; Breysse, C; Kauffmann, S; Cosserant, B; Souweine, B; Sautou, V

    2015-10-15

    Alternatives to DEHP plasticizers are used in various PVC medical devices (MD) for infusion. As they are able to migrate from these MDs into infused solutions, they may come into contact with patient. Different and specific clinical parameters influence their migration in at-risk situations such as infusion. In contrast to the regulations for Food Contact Materials (MCDA), there is currently no acceptable migration limits for the use of these plasticizers in clinical situations. In order to assess their migration, and thus control the risks linked to these MDs, we developed a migration model for the plasticizers in MDs. To this end, we applied a cross-disciplinary methodological process similar to that used in the food-processing industry, taking into account the MDs' conditions of use in clinical practice. The simulation model is simple and includes the following conditions: MD should be tested with a dynamic method that respects our established clinical assumption (2 L of infused solutions via 13 dm(2) of plasticized PVC), at a temperature of 25 °C and during 24 h of contact, using a 50/50 (v/v) ethanol/water simulant. This model could be proposed as a tool for the safety evaluation of the patients' exposure risk to plasticizers from PVC medical devices for infusions.

  7. Flame treatment for the selective wetting and separation of PVC and PET

    SciTech Connect

    Pascoe, R.D.; O'Connell, B

    2003-07-01

    Flame treatment has been used for many years to modify the surface of plastics to allow coatings to be added. The effect of the treatment is to produce hydrophilic species on the surface of the plastic making it water-wettable. The production of hydrophilic plastic surfaces is also required in the selective separation of plastics by froth flotation. For the process to be selective one plastic must be rendered hydrophilic while another remains hydrophobic. In this study the potential for separation of PVC and PET has been investigated. Flame treatment was shown to be very effective in producing a hydrophilic surface on both plastics, although the process was not selective under the conditions investigated. Raising the temperature of the plastics above their softening point produced a hydrophobic recovery. As the softening point of PVC was significantly lower than for PET it was possible to produce a significant difference in hydrophobicity, as judged using contact angle measurement. When immersed in water the contact angle of the PVC was found to be strongly dependent on the pH. Good separation efficiency of the two plastics was achieved by froth flotation from pH 4 to 9. One particular advantage of the technique is that no chemical reagents may be required in the flotation stage. The practicalities of designing a flake treatment system however have to be addressed before considering it to be a viable industrial process.

  8. Coupled recycling of PVC and glass wastes producing chlorine-free fuels and cement feed stock.

    PubMed

    Sung, Ho-jin; Noda, Reiji; Horio, Masayuki

    2009-01-01

    To utilize PVC and glass wastes in a landfill, a kinetic study was conducted for neutralization of HCl derived from PVC pyrolysis with sodium in soda glass. The effective diffusion coefficient of sodium at 550 degrees C was 3.3 x 10(-16) m2/s in steam atmosphere, but was 1.2 x 10(-17) m2/s in dry atmosphere. It was confirmed from experimental results in which considerable NaCl crystals were deposited on the surface of glass particles after 6 h reaction with particles of 25 microm in diameter that NaCl crystals' growth on the glass surface does not affect the neutralization rate rate in our experimental conditions. The effect of hydrothermal treatment was studied for the glass treated at 250 degrees C under a vapor pressure of 3.6 MPa for 5 h. Approximately 20 times higher rate than that of original glass was caused by the formation of the porous surface layer through which sodium ions can readily diffuse out The effect was not clear until steam pressure reached the above value. The absence of chlorine within the glass matrix was confirmed by EDS analysis on the cross section of glass cullets reacted with HCl gas. Neutralization of HCl gas with soda-glass conducted under steam atmosphere to increase the reaction rate is effective to recover energy and material from PVC and glass wastes.

  9. The Pseudomonas aeruginosa extracellular secondary metabolite, Paerucumarin, chelates iron and is not localized to extracellular membrane vesicles.

    PubMed

    Qaisar, Uzma; Kruczek, Cassandra J; Azeem, Muhammed; Javaid, Nasir; Colmer-Hamood, Jane A; Hamood, Abdul N

    2016-08-01

    Proteins encoded by the Pseudomonas aeruginosa pvcA-D operon synthesize a novel isonitrile functionalized cumarin termed paerucumarin. The pvcA-D operon enhances the expression of the P. aeruginosa fimbrial chaperone/usher pathway (cup) genes and this effect is mediated through paerucumarin. Whether pvcA-D and/or paerucumarin affect the expression of other P. aeruginosa genes is not known. In this study, we examined the effect of a mutation in pvcA-D operon the global transcriptome of the P. aeruginosa strain PAO1-UW. The mutation reduced the expression of several ironcontrolled genes including pvdS, which is essential for the expression of the pyoverdine genes. Additional transcriptional studies showed that the pvcA-D operon is not regulated by iron. Exogenously added paerucumarin enhanced pyoverdine production and pvdS expression in PAO1-UW. Iron-chelation experiments revealed that purified paerucumarin chelates iron. However, exogenously added paerucumarin significantly reduced the growth of a P. aeruginosa mutant defective in pyoverdine and pyochelin production. In contrast to other secondary metabolite, Pseudomonas quinolone signal (PQS), paerucumarin is not localized to the P. aeruginosa membrane vesicles. These results suggest that paerucumarin enhances the expression of iron-controlled genes by chelating iron within the P. aeruginosa extracellular environment. Although paerucumarin chelates iron, it does not function as a siderophore. Unlike PQS, paerucumarin is not associated with the P. aeruginosa cell envelope.

  10. Coumarin-Based Fluorescent Probes for Dual Recognition of Copper(II) and Iron(III) Ions and Their Application in Bio-Imaging

    PubMed Central

    García-Beltrán, Olimpo; Cassels, Bruce K.; Pérez, Claudio; Mena, Natalia; Núñez, Marco T.; Martínez, Natalia P.; Pavez, Paulina; Aliaga, Margarita E.

    2014-01-01

    Two new coumarin-based “turn-off” fluorescent probes, (E)-3-((3,4-dihydroxybenzylidene)amino)-7-hydroxy-2H-chromen-2-one (BS1) and (E)-3-((2,4-dihydroxybenzylidene)amino)-7-hydroxy-2H-chromen-2-one (BS2), were synthesized and their detection of copper(II) and iron(III) ions was studied. Results show that both compounds are highly selective for Cu2+ and Fe3+ ions over other metal ions. However, BS2 is detected directly, while detection of BS1 involves a hydrolysis reaction to regenerate 3-amino-7-hydroxycoumarin (3) and 3,4-dihydroxybenzaldehyde, of which 3 is able to react with copper(II) or iron(III) ions. The interaction between the tested compounds and copper or iron ions is associated with a large fluorescence decrease, showing detection limits of ca. 10−5 M. Preliminary studies employing epifluorescence microscopy demonstrate that Cu2+ and Fe3+ ions can be imaged in human neuroblastoma SH-SY5Y cells treated with the tested probes. PMID:24419164

  11. Iron(III) complex of N-phenylethylenediamine derivative of amine bis(phenol) ligand as model for catechol dioxygenase: Synthesis, characterization and complexation studies

    NASA Astrophysics Data System (ADS)

    Poureskandari, Maryam; Safaei, Elham; Maryam Sajjadi, S.; Karimpour, Touraj; Jaglicic, Zvonko; Lee, Yong-Ill

    2015-08-01

    A new amine bis(phenol) ligand (HLPEA), was synthesized and characterized by IR, 1H NMR spectroscopic techniques and elemental analyses. The mononuclear iron(III) complex (FeLPEA) of this ligand has been prepared and characterized by IR and UV-Vis spectroscopic techniques, ESI-MS, elemental analyses and magnetic susceptibility studies. The molecular mass of complex was determined by ESI-MS which is corresponding to a mononuclear iron(III) complex consist of amine bis(phenolate) ligand coordinated to Fe(III) including chlorine atoms and solvent molecule. The variable temperature magnetic susceptibility indicates paramagnetic character of complex. To determine the formation constant of the complex, multivariate hard modeling method was applied on spectral data collected throughout the titration of Fe(III) with ligand. FeLPEA shows good catalytic activity in cleavage oxygenation of 3,5-di-tert-butyl catechol in the presence of dioxygen at room temperature with a nearly complete conversion and particularly extradiol cleavage mechanism.

  12. Microbiological safety of household membrane water filter.

    PubMed

    Zhang, Yongli; Wang, Qing; Lou, Wei; Wang, Yuxin; Zhu, Xuan

    2013-04-01

    Waterborne pathogens outbreaks are major reasons of diarrhea disease worldwide. Detecting and monitoring emerging waterborne pathogens (EWPs) is important for drinking water microbiological safety. The microbiological safety of household water hollow fiber membrane filter which is the end of drinking water treatment process was studied with heterotrophic plate count (HPC) and real-time PCR method. The effect of the flow rate, idle time and washing fashion were investigated. Among the selected filters from three manufacturers, only the PVDF membrane water filter (Brand B) could achieve a good water purification criteria. Brand A was found a certain degree of EWPs in its effluent. The lowest bacteria-removing efficiency of the PVC membrane water filter was found Brand C. Our study showed that the microorganisms could reach up to 10(6) CFU ml(-1) and the 16s rDNA could reach up to 10(6) copies ml(-1) in the initial filtrate of Brand C. More species and amounts of EWPs were detected in the washing water. These results suggested that the popular household membrane filters might cause microbiological risks at certain circumstances such as the shock load of EWPs and leakage of the membranes in the case of abnormal source water or poor membrane filter quality.

  13. Vacuolar degradation of two integral plasma membrane proteins, AtLRR84A and OsSCAMP1, is cargo ubiquitination-independent and prevacuolar compartment-mediated in plant cells.

    PubMed

    Cai, Yi; Zhuang, Xiaohong; Wang, Junqi; Wang, Hao; Lam, Sheung Kwan; Gao, Caiji; Wang, Xiangfeng; Jiang, Liwen

    2012-07-01

    In plant cells, how integral plasma membrane (PM) proteins are degraded in a cargo ubiquitination-independent manner remains elusive. Here, we studied the degradative pathway of two plant PM proteins: AtLRR84A, a type I integral membrane protein belonging to the leucine-rich repeat receptor-like kinase protein family, and OsSCAMP1 (rice secretory carrier membrane protein 1), a tetraspan transmembrane protein located on the PM and trans-Golgi network (TGN) or early endosome (EE). Using wortmannin and ARA7(Q69L) mutant that could enlarge the multivesicular body (MVB) or prevacuolar compartment (PVC) as tools, we demonstrated that, when expressed as green fluorescent protein (GFP) fusions in tobacco BY-2 or Arabidopsis protoplasts, both AtLRR84A and OsSCAMP1 were degraded in the lytic vacuole via the internal vesicles of MVB/PVC in a cargo ubiquitination-independent manner. Such MVB/PVC-mediated vacuolar degradation of PM proteins was further supported by immunocytochemical electron microscopy (immunoEM) study showing the labeling of the fusions on the internal vesicles of the PVC/MVB. Thus, cargo ubiquitination-independent and PVC-mediated degradation of PM proteins in the vacuole is functionally operated in plant cells.

  14. Forensic utility of the carbon isotope ratio of PVC tape backings

    NASA Astrophysics Data System (ADS)

    Stern, L. A.; Thompson, A. H.; Mehltretter, A. H.; McLaskey, V.; Parish, A.; Aranda, R.

    2008-12-01

    Forensic interest in adhesive tapes with PVC-backings (polyvinyl chloride, electrical tapes) derives from their use in construction of improvised explosive devices, drug packaging and in a variety of other illicit activities. Due to the range of physical characteristics and chemical compositions of such tapes, traditional microscopic and chemical analysis of the tape backings and adhesives offer a high degree of discrimination between tapes from different manufacturers and products. To evaluate whether carbon isotope ratios may be able to increase discrimination of electrical tapes, particularly with regards to different tapes of the same product, we assessed the PVC-backings of 87 rolls of black electrical tape for their δ13C values. The adhesive on these tapes was physically removed with hexane, and plasticizers within the PVC tape backings were removed by three-20 minute extractions with chloroform. The δ13C values of the PVC tape backings ranged between -23.8 and -41.5 (‰ V-PDB). The carbon isotopic variation within a product (identical brand and product identification) is significant, based on five products with at least 3 rolls (ranges of 7.4‰ (n=3), 10.0‰ (n=6), 4.2‰ (n=16), 3.8‰ (n=6), and 11.5‰ (n=8), respectively). There was no measurable carbon isotope variation in regards to the following: a) along the length of a roll (4 samples from 1 roll); b) between the center and edge of a strip of tape (1 pair); c) between rolls assumed to be from the same lot of tape (2 pairs); d) between different rolls from the same batch of tape (same product purchased at the same time and place; 5 pairs); and e) between samples of a tape at room temperature, heated to 50° C and 80° C for 1 week. For each sample within the population of 87 tapes, carbon isotopes alone exclude 80 to 100% of the tapes as a potential match, with an average exclusion power of 92.5%, using a window of ± 0.4‰. Carbon isotope variations originate from variations in starting

  15. The pvc Gene Cluster of Pseudomonas aeruginosa: Role in Synthesis of the Pyoverdine Chromophore and Regulation by PtxR and PvdS

    PubMed Central

    Stintzi, Alain; Johnson, Zaiga; Stonehouse, Martin; Ochsner, Urs; Meyer, Jean-Marie; Vasil, Michael L.; Poole, Keith

    1999-01-01

    A putative operon of four genes implicated in the synthesis of the chromophore moiety of the Pseudomonas aeruginosa siderophore pyoverdine, dubbed pvcABCD (where pvc stands for pyoverdine chromophore), was cloned and sequenced. Mutational inactivation of the pvc genes abrogated pyoverdine biosynthesis, consistent with their involvement in the biosynthesis of this siderophore. pvcABCD expression was negatively regulated by iron and positively regulated by both PvdS, the alternate sigma factor required for pyoverdine biosynthesis, and PtxR, a LysR family activator previously implicated in exotoxin A regulation. PMID:10383985

  16. Experimental and Theoretical Investigations of Magnetic Exchange Pathways in Structurally Diverse Iron(III) Schiff-Base Complexes.

    PubMed

    Herchel, Radovan; Nemec, Ivan; Machata, Marek; Trávníček, Zdeněk

    2015-09-08

    The synthesis, and the structural and magnetic properties, of the following new iron(III) Schiff base complexes with the {O',N,O″}-chelating ligand H2L (2-hydroxyphenylsalicylaldimine) are reported: K[FeL2]·H2O (1), (Pr3NH)[FeL2]·2CH3OH (2), [FeL(bpyO2) (CH3OH)][FeL2]·CH3OH (3), [Fe2L3(CH3OH)]·2CH3OH·H2O (4), and [{Fe2L2}(μ-OH)2{FeL(bpyO2)}2][BPh4]2·2H2O (5), where Pr3NH(+) represents the tripropylammonium cation and bpyO2 stands for 2,2'-bipyridine-N-dioxide. A thorough density functional theory (DFT) study of magnetic interactions (the isotropic exchange) at the B3LYP/def-TZVP level of theory was employed, and calculations have revealed superexchange pathways through intramolecular/intermolecular noncovalent contacts (π-π stacking, C-H···O and O-H···O hydrogen bonds, diamagnetic metal cations) and/or covalent bonds ((μ-O(Ph), μ-OH) or bis(μ-O(Ph)) bridging modes), which helped us to postulate trustworthy spin Hamiltonians for magnetic analysis of experimental data. Within the reported family of compounds 1-5, the mediators of the antiferromagnetic exchange can be sorted by their increasing strength as follows: π-π stacking (J(DFT) = -0.022 cm(-1)/J(mag) = -0.025(4) cm(-1) in 2) < C-H···O contacts and π-π stacking (J(DFT) = -0.19 cm(-1)/J(mag) = -0.347(9)cm(-1) in 1) < O-H···O hydrogen bonds (J(DFT) = -0.53 cm(-1)/J(mag) = -0.41(1) cm(-1) in 3) < bis(μ-O(Ph)) bridge (J(DFT) = -13.8 cm(-1)/J(mag) = -12.3(9) cm(-1) in 4) < (μ-O(Ph), μ-OH) bridge (J(DFT) = -18.0 cm(-1)/J(mag) = -17.1(2) cm(-1) in 5), where J(DFT) and J(mag) are the isotropic exchange parameters derived from DFT calculations, and analysis of the experimental magnetic data, respectively. The good agreement between theoretically calculated and experimentally derived isotropic exchange parameters suggests that this procedure is applicable also for other chemical and structural systems to interpret magnetic data properly.

  17. Stability, compatibility and plasticizer extraction of quinine injection added to infusion solutions and stored in polyvinyl chloride (PVC) containers.

    PubMed

    Faouzi, M A; Khalfi, F; Dine, T; Luyckx, M; Brunet, C; Gressier, B; Goudaliez, F; Cazin, M; Kablan, J; Belabed, A; Cazin, J C

    1999-12-01

    The stability of quinine was determined in various diluents and in polyvinyl chloride (PVC) containers. The release of diethyhexyl phthalate (DEHP) from PVC bags into intravenous infusions of quinine was also measured. We used an injection of two doses of quinine; quiniforme at 500 mg and quinimax at 400 mg in either 250- or 500-ml PVC infusion bags containing 5% dextrose, to give initial nominal concentrations of 2 or 1 mg ml(-1) quiniforme and 1.6 or 0.8 mg ml(-1) quinimax, the mean concentrations commonly used in clinical practice. Samples were assayed by stability-indicating high-performance liquid chromatography (HPLC) and the clarity was determined visually. Experiments were conducted to determine whether the stability and compatibility of quinine would be compromised, and whether DEHP would be leached from PVC bags and PVC administration sets during storage and simulated infusion. There was no substantial loss of quiniforme and quinimax over 1- or 2-h simulated infusion irrespective of the diluent, and storage during 8 h at 22 degrees C, 48 or 72 h at 4 degrees C and 96 h at 45 degrees C. Leaching of DEHP was also detected during simulated infusion delivery using PVC bags and PVC administration sets. The quantity was less than 2 microg ml(-1). During storage at 4 degrees C and room temperature the leaching of DEHP was low, but when the temperature was 45 degrees C the quantity was high, 21 microg ml(-1). To minimise patient exposure to DEHP, quinine solutions with all drugs should be infused immediately or stored for a maximum of 48 h at 4 degrees C.

  18. Effect of relative humidity and temperature on PVC degradation under gamma irradiation: Evolution of HCl production Yields

    NASA Astrophysics Data System (ADS)

    Labed, V.; Obeid, H.; Ressayre, K.

    2013-03-01

    The separate and combined effects of the relative humidity and temperature were investigated on the HCl production yields arising from two types of PVC subjected to gamma irradiation (pure PVC and PVC formulated with plasticizing additives). The test procedure developed included experiments performed at different dose rates (400 Gy h-1 and 4 kGy h-1), temperatures (room temperature and 70 °C) and relative humidity values (<10%, 70-75%, and 100%), for irradiation doses ranging from 0.1 to 4 MGy. These operating conditions are representative of applications in a nuclear environment. For the plasticized PVC at low dose rates, raising the temperature increases the HCl production by a factor of about 1.3, with either low or high relative humidity. For pure PVC, depending on the humidity and dose rate, G(HCl) varies differently with the temperature: at low humidity and low dose rates, G(HCl) increases by a factor of 1.7 for a 45 °C temperature increase; at high humidity, the same temperature increase does not result in a significant increase of G(HCl). The influence of the relative humidity on HCl production has not been clearly identified and interpreted. The relative humidity appears to be a factor limiting the effects of temperature on the formation of HCl from pure PVC at high dose rates. The G values remain constant and even diminish under some experimental conditions. For plasticized PVC, the relative humidity has no influence on the HCl production yields.

  19. Membrane stabilizer

    DOEpatents

    Mingenbach, W.A.

    1988-02-09

    A device is provided for stabilizing a flexible membrane secured within a frame, wherein a plurality of elongated arms are disposed radially from a central hub which penetrates the membrane, said arms imposing alternately against opposite sides of the membrane, thus warping and tensioning the membrane into a condition of improved stability. The membrane may be an opaque or translucent sheet or other material. 10 figs.

  20. Preparation, Characterization, and Analytical Application of Ramipril Membrane-Based Ion-Selective Electrode

    PubMed Central

    Arida, Hassan; Ahmed, Mona; Ali, Abdallah

    2009-01-01

    The fabrication and electrochemical evaluation of two PVC membrane-based Ion-Selective electrodes responsive for ramipril drug have been proposed. The sensitive membranes were prepared using ramipril-phosphomolibdate and ramipril-tetraphenylborate ion-pair complexes as electroactive sensing materials in plasticized PVC support. The electrodes based on these materials provide near-Nernestian response (sensitivity of 53 ± 0.5–54 ± 0.5 mV/concentration decade) covering the concentration range of 1.0 × 10−2–1.0 × 10−5 mol L−1 with a detection limit of 3.0 × 10−6–4.0 × 10−6 mol L−1. The suggested electrodes have been successfully used in the determination of ramipril drug in some pharmaceutical formulations using direct potentiometry with average recovery of >96% and mean standard deviation of <3% (n = 5). PMID:20140081

  1. Evaluation of employee exposure to organic tin compounds used as stabilizers at PVC processing facilities.

    PubMed

    Boraiko, Carol; Batt, John

    2005-02-01

    Organic tin compounds are primary substances used as heat stabilizers by the polyvinyl chloride (PVC) industry. The use of these compounds in the PVC industry is generally well controlled, usually by automated processes. This study was conducted to provide an overview of worker exposure to organic tin compounds at PVC processing facilities and to verify that these exposures are below the threshold limit value (TLV((R))) set by the American Conference of Governmental Industrial Hygienists for organic tin. The basis of the TLV indicates the principal concern is to minimize adverse effects on immune function and the central nervous system from airborne exposure to organic tin. The TLV has a skin designation based on the potential for percutaneous absorption; the TLVs for inhalation exposures are based on the presumption that there is no concurrent exposure via the skin and oral ingestion routes. Personal exposure monitoring was conducted following the National Institute for Occupational Safety and Health (NIOSH) 5504 sampling method and a modified version of the NIOSH analytical method. The results were reported as"total tin."The data indicated no average exposure levels for individual tasks exceeded the organic tin TLV, and 96%of results the samples were less than 20%of the TLV. Only 1 sample of 102 exceeded the TLV, and the individual was wearing appropriate respiratory protection. Subsequent investigation indicated the highest exposures occurred while the operators were conducting tasks that included manual handling of the organic tin compounds. These data suggest manual operations may have a greater potential for organic tin exposure.

  2. Determination of bisphenol A in, and its migration from, PVC stretch film used for food packaging.

    PubMed

    López-Cervantes, J; Paseiro-Losada, P

    2003-06-01

    Bisphenol A (BPA) is used as an additive in polyvinyl chloride (PVC) products, including stretch films used for food packaging. The BPA contents were investigated of several brands of stretch film bought locally but marketed internationally or throughout Spain and which were presumably produced at different manufacturing plants. Their major components were identified by FTIR (Fourier Transform Infrared Spectrometry) and horizontal attenuated total reflectance, and the migration of BPA from these materials into the standard European Union food simulants was determined by high-performance liquid chromatography (HPLC) using both fluorescence (FL) and ultraviolet (UV) detection, the identity of the analyte being confirmed by gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS). The two HPLC detection methods had different detection limits (30 microg x l(-1) for UV, 3 microg x l(-1) for FL), but afforded virtually identical BPA determinations for the samples tested. BPA contents ranging from 40 to 100 mg x kg(-1) were found in three of the five PVC-based films analysed, and a content of 500 mg x kg(-1) was found in a fourth; for these determinations, extraction into acetonitrile was used. In standard tests of migration into water, 3% acetic acid and olive oil over 10 days at 40 degrees C, migration from a given film was in all cases greatest into olive oil. Migration from the films with non-zero BPA contents ranged from 3 to 31 microg x dm(-2), values higher than those reported for many other food-contact materials, but lower than the European Union specific migration limit for BPA. PVC stretch film nevertheless may make a significant contribution to contamination of foodstuffs by BPA, and should be taken into account in estimating BPA intake or exposure to this substance.

  3. Migration of DEHP and DINP into dust from PVC flooring products at different surface temperature.

    PubMed

    Jeon, Seunghwan; Kim, Ki-Tae; Choi, Kyungho

    2016-03-15

    Phthalates are important endocrine disrupting chemicals that have been linked to various adverse human health effects. Phthalates are ubiquitously present in indoor environment and could enter humans. Vinyl or PVC floorings have been recognized as one of important sources of phthalate release to indoor environment including house dust. In the present study, we estimated the migration of di(2-ethylhexyl)phthalate (DEHP) and di-isononyl phthalate (DINP) from the flooring materials into the dust under different heating conditions. For this purpose, a small chamber specifically designed for the present study and a Field and Laboratory Emission Cell (FLEC) were used, and four major types of PVC flooring samples including two UV curing paint coated, an uncoated residential, and a wax-coated commercial type were tested. Migration of DEHP was observed for an uncoated residential type and a wax-coated commercial type flooring. After 14 days of incubation, the levels of DEHP in the dust sample was determined at room temperature on average (standard deviation) at 384 ± 19 and 481 ± 53 μg/g, respectively. In contrast, migration of DINP was not observed. The migration of DEHP was strongly influenced by surface characteristics such as UV curing coating. In the residential flooring coated with UV curing paint, migration of DEHP was not observed at room temperature. But under the heated condition, the release of DEHP was observed in the dust in the FLEC. Migration of DEHP from flooring materials increased when the flooring was heated (50 °C). In Korea, heated flooring system, or 'ondol', is very common mode of heating in residential setting, therefore the contribution of PVC flooring to the total indoor DEHP exposure among general population is expected to be greater especially during winter season when the floor is heated.

  4. Miniaturizable Ion-Selective Arrays Based on Highly Stable Polymer Membranes for Biomedical Applications

    PubMed Central

    Mir, Mònica; Lugo, Roberto; Tahirbegi, Islam Bogachan; Samitier, Josep

    2014-01-01

    Poly(vinylchloride) (PVC) is the most common polymer matrix used in the fabrication of ion-selective electrodes (ISEs). However, the surfaces of PVC-based sensors have been reported to show membrane instability. In an attempt to overcome this limitation, here we developed two alternative methods for the preparation of highly stable and robust ion-selective sensors. These platforms are based on the selective electropolymerization of poly(3,4-ethylenedioxythiophene) (PEDOT), where the sulfur atoms contained in the polymer covalently interact with the gold electrode, also permitting controlled selective attachment on a miniaturized electrode in an array format. This platform sensor was improved with the crosslinking of the membrane compounds with poly(ethyleneglycol) diglycidyl ether (PEG), thus also increasing the biocompatibility of the sensor. The resulting ISE membranes showed faster signal stabilization of the sensor response compared with that of the PVC matrix and also better reproducibility and stability, thus making these platforms highly suitable candidates for the manufacture of robust implantable sensors. PMID:24999717

  5. Structural, Optical and Mechanical properties of PVC/PMMA Polymer Blend by Spectroscopic Techniques

    NASA Astrophysics Data System (ADS)

    Patel, Gaurang; Sureshkumar, M. B.; Patel, Purvi

    2011-10-01

    PVC/PMMA polymer blends were characterized by Fourier Transform Infrared Spectroscopy (FTIR), UV-VIS Spectroscopy and mechanical analysis. The changes in mechanical properties are reflected by the changes in the IR spectrum. The mechanical properties of such poly blends revealed a substantial increase in Young's modulus and ultimate tensile strength after initial drop at 10% of PMMA. Optical properties such as the absorption coefficient, optical (Direct/Indirect) energy gap were calculated. The effects of different blending percentage on these parameters have been discussed and their results are co-related with IR study.

  6. PVC/CaCO3 Nanocomposites: Influence of nanoparticle surface treatment on properties

    NASA Astrophysics Data System (ADS)

    Bonadies, Irene; Avella, Maurizio; Avolio, Roberto; Carfagna, Cosimo; Emanuela Errico, Maria; Gentile, Gennaro

    2010-06-01

    The influence of nanosized calcium carbonate on the gelation process, thermal stability and mechanical properties of rigid poly(vinyl chloride) has been studied. The gelation time of rigid PVC/calcium carbonate nanocomposites depends on the percentage and superficial treatment of CaCO3. The results of thermogravimetric analysis underline an improvement of the thermal stability as a function of the surface modifier. Finally, the flexural modulus, the flexural strength as well as the critical stress intensity factor increase with the addition of poly(acrylic acid) (PAA) or poly(butadiene-co-acrilonitrile-co-acrylic acid) (PBAA) coated nanoparticles.

  7. Treatment of PVC using an alternative low energy ion bombardment procedure

    NASA Astrophysics Data System (ADS)

    Rangel, Elidiane C.; dos Santos, Nazir M.; Bortoleto, José Roberto R.; Durrant, Steven F.; Schreiner, Wido H.; Honda, Roberto Y.; Rangel, Rita de Cássia C.; Cruz, Nilson C.

    2011-12-01

    In many applications, polymers have progressively substituted traditional materials such as ceramics, glasses, and metals. Nevertheless, the use of polymeric materials is still limited by their surface properties. Frequently, selective modifications are necessary to suit the surface to a given application. Amongst the most common treatments, plasma immersion ion implantation (PIII) has attracted the attention of many researchers owing to its versatility and practicality. This method, however, requires a power supply to provide high voltage (tens of kV) negative pulses, with a controlled duty cycle, width and frequency. Owing to this, the implementation of PIII on the industrial scale can become economically inviable. In this work, an alternative plasma treatment that enables low energy ion bombardment without the need of a high voltage pulse generator is presented. To evaluate the efficiency of the treatment of polymers, polyvinylchloride, PVC, specimens were exposed to 5 Pa argon plasmas for 3600 s, at excitation powers, P, of between 10 and 125 W. Through contact angle and atomic force microscopy data, the influence of P on the wettability, surface free energy and roughness of the samples was studied. Surface chemical composition was measured by X-ray photoelectron spectroscopy, XPS. To evaluate the effect of aging under atmospheric conditions, contact angle and XPS measurements were performed one and 1334 days after the treatment. The plasma potential and ion density around the driven electrode were determined from Langmuir probe measurements while the self-bias potential was derived with the aid of an oscilloscope. From these data it was possible to estimate the mean energy of ions bombarding the PVC surface. Chlorine, carbon and oxygen contamination were detected on the surface of the as-received PVC. Upon exposure to the plasma, the proportion of chlorine was observed to decrease while that of oxygen increased. Consequently, the wettability and surface energy

  8. A creep apparatus to explore the quenching and ageing phenomena of PVC films

    NASA Technical Reports Server (NTRS)

    Lee, H. H. D.; Mcgarry, F. J.

    1991-01-01

    A creep apparatus has been constructed for an in situ determination of length and length change. Using this apparatus, the creep behavior of PVC thin films associated with quenching and aging was studied. The more severe the quench through the glass transition temperature, the greater is the instantaneous elastic deformation and the subsequent creep behavior. As aging proceeds, the quenched films gradually lose the ductility incurred by quenching. These results agree well with the well-known phenomena of physical aging. Thus, the changes reflecting molecular mobilities due to quenching and aging can be properly monitored by such a creep apparatus.

  9. Production of Laccase by Cochliobolus sp. Isolated from Plastic Dumped Soils and Their Ability to Degrade Low Molecular Weight PVC

    PubMed Central

    Sumathi, Tirupati; Sri Lakshmi, Akula; SaiGopal, D. V. R.

    2016-01-01

    One of the utmost man-made problems faced today has been the ever-increasing plastic waste filling the world. It accounts for an estimated 20–30% (by volume) of municipal solid waste in landfill sites worldwide. Research on plastic biodegradation has been steadily growing over the past four decades. Several fungi have been identified that produce enzymes capable of plastic degradation in various laboratory conditions. This paper presents a study that determined the ability of fungi to degrade low molecular weight polyvinyl chloride (PVC) by the enzyme laccase. We have isolated a fungal species, Cochliobolus sp., from plastic dumped soils and they were cultured on Czapek Dox Agar slants at 30°C. The effectiveness of this fungal species on the degradation of commercial low molecular weight polyvinyl chloride (PVC) was studied under laboratory conditions. Significant differences were observed from the FTIR, GC-MS, and SEM results in between control and Cochliobolus sp. treated PVC. PMID:27293894

  10. Influence of Al2O3 on the ionic conductivity of plasticized PVC-PEG blend polymer electrolytes

    NASA Astrophysics Data System (ADS)

    Ravindran, D.; Vickraman, P.

    2016-05-01

    Polymer electrolytes with PVC-PEG blend as host matrix and LiClO4 as dopant salt was prepared through conventional solution casting method. To enhance the conductivity propylene carbonate (PC) was used as plasticizer. The influence of ceramic filler Al2O3 on the conductivity of the electrolyte films were studied by varying the (PVC: Al2O3) ratio. The films were subjected to XRD, complex impedance analysis and SEM analysis. The XRD studies reveal a marginal increase in the amorphous phase of the electrolyte films due to the incorporation of filler. The AC impedance analysis shows the dependency of ionic conductivity on the content (wt %) of filler and exhibit a maximum at 4 wt% filler. The SEM analysis depicts the occurrence of phase separation in electrolyte which is attributed to the poor solubility of polymer PVC in the liquid electrolyte.

  11. Investigation of unstabilized polyvinyl chloride (PVC) for use as a long-term UV dosimeter: preliminary results

    NASA Astrophysics Data System (ADS)

    Amar, Abdurazaq; Parisi, Alfio V.

    2012-08-01

    A new chemical UV dosimeter with a larger dose capacity than existing chemical dosimeters has been investigated for long-term UV measurements. Unstabilized polyvinyl chloride (PVC), cast in 40 µm thick film, has been found to respond to at least 745 SED (Standard Erythema Dose = 100 J m-2) of solar UV radiation, which is equivalent to about two to three summer weeks of exposure in subtropical sites. The UV-induced changes in the PVC dosimeter were quantified using a Fourier transform infrared spectrophotometer and the decrease in the absorption intensity of the 1064 cm-1 peak was employed to quantify these changes. Dose response curves have been established by relating the decrease in the PVC dosimeter's absorption intensity at 1064 cm-1 to the corresponding absolute and erythemal UV exposure dose.

  12. Adhesion of slime producing Staphylococcus epidermidis strains to PVC and diamond-like carbon/silver/fluorinated coatings.

    PubMed

    Katsikogianni, M; Spiliopoulou, I; Dowling, D P; Missirlis, Y F

    2006-08-01

    Staphylococcus epidermidis has emerged as a pathogen associated with infections of implanted medical devices. Bacterial adhesion is a crucial step in infection on biomaterial surfaces. To quantitatively determine the relationship between poly (vinyl chloride) (PVC) surface properties and bacterial adhesion, we have compared attachment of slime-producing S. epidermidis strains on PVC and various coatings under flow conditions. Bacterial adhesion and colonization was quantified by counting the viable organisms on the adherent surface as well as by scanning electron microscopy, epifluorescence microscopy and atomic force microscopy. Fluorination of the PVC surface encourages S. epidermidis adhesion whereas; diamond-like carbon (DLC) and especially silver (Ag) coatings seem to inhibit its adhesion. In most materials, the number of adherent bacteria decreased with the increase of shear rate. These results indicate that bacterial adhesion is influenced by the chemical properties of the polymeric surfaces, the surface roughness and the associated flow conditions.

  13. Rheological studies of PMMA-PVC based polymer blend electrolytes with LiTFSI as doping salt.

    PubMed

    Liew, Chiam-Wen; Durairaj, R; Ramesh, S

    2014-01-01

    In this research, two systems are studied. In the first system, the ratio of poly (methyl methacrylate) (PMMA) and poly (vinyl chloride) (PVC) is varied, whereas in the second system, the composition of PMMA-PVC polymer blends is varied with dopant salt, lithium bis (trifluoromethanesulfonyl) imide (LiTFSI) with a fixed ratio of 70 wt% of PMMA to 30 wt% of PVC. Oscillation tests such as amplitude sweep and frequency sweep are discussed in order to study the viscoelastic properties of samples. Elastic properties are much higher than viscous properties within the range in the amplitude sweep and oscillatory shear sweep studies. The crossover of G' and G'' is absent. Linear viscoelastic (LVE) range was further determined in order to perform the frequency sweep. However, the absence of viscous behavior in the frequency sweep indicates the solid-like characteristic within the frequency regime. The viscosity of all samples is found to decrease as shear rate increases.

  14. Rheological Studies of PMMA–PVC Based Polymer Blend Electrolytes with LiTFSI as Doping Salt

    PubMed Central

    Liew, Chiam–Wen; Durairaj, R.; Ramesh, S.

    2014-01-01

    In this research, two systems are studied. In the first system, the ratio of poly (methyl methacrylate) (PMMA) and poly (vinyl chloride) (PVC) is varied, whereas in the second system, the composition of PMMA–PVC polymer blends is varied with dopant salt, lithium bis (trifluoromethanesulfonyl) imide (LiTFSI) with a fixed ratio of 70 wt% of PMMA to 30 wt% of PVC. Oscillation tests such as amplitude sweep and frequency sweep are discussed in order to study the viscoelastic properties of samples. Elastic properties are much higher than viscous properties within the range in the amplitude sweep and oscillatory shear sweep studies. The crossover of and is absent. Linear viscoelastic (LVE) range was further determined in order to perform the frequency sweep. However, the absence of viscous behavior in the frequency sweep indicates the solid-like characteristic within the frequency regime. The viscosity of all samples is found to decrease as shear rate increases. PMID:25051241

  15. High photocatalytic degradation activity of the polyvinyl chloride (PVC)-vitamin C (VC)-TiO2 nano-composite film.

    PubMed

    Yang, Changjun; Gong, Chuqing; Peng, Tianyou; Deng, Kejian; Zan, Ling

    2010-06-15

    A novel photodegradable polyvinyl chloride (PVC)-vitamin C (VC)-TiO(2) nano-composite film was prepared by embedding VC modified nano-TiO(2) photocatalyst into the commercial PVC plastic. The solid-phase photocatalytic degradation behavior of PVC-VC-TiO(2) nano-composite film under UV light irradiation was investigated and compared with those of the PVC-TiO(2) film and the pure PVC film, with the aid of UV-Vis spectroscopy, scanning electron microscopy (SEM), weight loss monitoring, and X-ray diffraction spectra (XRD). The results show that PVC-VC-TiO(2) nano-composite film has a high photocatalytic activity; the photocatalytic degradation rate of it is two times higher than that of PVC-TiO(2) film and fifteen times higher than that of pure PVC film. The optimal mass ratio of VC to TiO(2) is found to be 0.5. The mechanism of enhancing photocatalytic activity is attributed to the formation of a Ti(IV)-VC charge-transfer complex with five-member chelate ring structure and a rapid photogenerated charge separation is thus achieved.

  16. Determination of the Composition and Quantity of Phthalate Ester Additives in PVC Children's Toys. Greenpeace Research Laboratories Technical Note 06/97.

    ERIC Educational Resources Information Center

    Stringer, Ruth; Labounskaia, Irina; Santillo, David; Johnston, Paul; Siddorn, John; Stephenson, Angela

    Polyvinyl chloride (vinyl or PVC) is widely used in toys and other children's products. This study, conducted by Greenpeace, examined the composition and quantity of phthalate ester additives in children's PVC toys, used to give the toys added flexibility. Drawn from 17 countries, a total of 71 toys designed to be chewed by babies and young…

  17. Spectrophotometric studies on ion-pair extraction equilibria of the iron(ii) and iron(III) complexes with 4-(2-pyridylazo)resorcinol.

    PubMed

    Hoshino, H; Yotsuyanagi, T

    1984-07-01

    The ion-pair extraction equilibria of the iron(II) and iron(III) chelates of 4-(2-pyridylazo)resorcinol (PAR, H(2)L) are described. The anionic chelates were extracted into chloroform with benzyldimethyltetradecylammonium chloride (QC1) as counter-ion. The extraction constants were estimated to be K(ex1)(Fe(II)) = [Q{Fe(II)(HL)L}](0)/[Q(+)][{Fe(II)(HL)L}(-)] = 10(8.59 +/- 0.11), K(ex2)(Fe(II)) = [Q(2){Fe(II)L(2)}](o)/ [Q(+)](2)[{Fe(II)L(2)}(2-)] = 10(12.17 +/- 0.10) and K(ex1)(Fe(III)) = [Q{Fe((III))L(2)}](o)/(Q(+)][{Fe(III)L(2)}(-)] = 10(6.78 +/- 0.15) at I = 0.10 and 20 degrees , where [ ](o) is concentration in the chloroform phase. Aggregation of Q{Fe(III)L(2)} in chloroform was observed and the dimerization constant (K(d) = [Q(2){Fe(III)L(2)}(2)](o)/[Q{Fe(III)L(2)}](o)(2)) was evaluated as log K(d) = 4.3 +/- 0.3 at 20 degrees . The neutral chelates of {Fe(II)(HL)(2)} and {Fe(III)(HL)L}, and the ion-pair of the cationic chelate, {Fe(III)(HL)(2)}ClO(4), were also extracted into chloroform or nitrobenzene. The relationship between the forms and extraction properties of the iron(II) and iron(III) PAR chelates are discussed in connection with those of the nickel(II) and cobalt(III) complexes. Correlation between the extraction equilibrium data and the elution behaviour of some PAR chelates in ion-pair reversed-phase partition chromatography is also discussed.

  18. Dinuclear and 1D iron(III) Schiff base complexes bridged by 4-salicylideneamino-1,2,4-triazolate: X-ray structures and magnetic properties.

    PubMed

    Herchel, Radovan; Pavelek, Lubomír; Trávníček, Zdeněk

    2011-11-28

    Four new iron(III) complexes were obtained by the reaction of 4-salicylideneamino-1,2,4-triazole (Hsaltrz) and selected dinuclear μ-oxo-bridged iron(III) Schiff base complexes [{FeL(4)}(2)(μ-O)], where L(4) represents a terminal tetradentate dianionic Schiff-base ligand. X-ray structural analysis revealed a novel bridging mode of κN,κO of the saltrz ligand to form dinuclear complexes [{Fe(salen)(μ-saltrz)}(2)]·CH(3)OH (1) (H(2)salen = N,N'-ethylenebis(salicylimine)) and [{Fe(salpn)(μ-saltrz)}(2)] (2) (H(2)salpn = N,N'-1,2-propylenbis(salicylimine)), whereas one-dimensional (1D) zig-zag chains were formed in the case of [{Fe(salch)(μ-saltrz)}·0.5CH(3)OH](n) (3) (H(2)salch = N,N'-cyclohexanebis(salicylimine)) and [Fe(salophen)(μ-saltrz)](n) (4) (H(2)salophen = N,N'-o-phenylenebis(salicylimine)). It was also shown that the rigidity of the terminal ligand L(4) can be considered as the key factor for the molecular dimensionality of the products. The thorough magnetic analysis based on SQUID experiments, including the isotropic exchange and the zero-field splitting of both temperature and field dependent data, was performed for dimeric (1 and 2) and also for polymeric compounds (3 and 4) and revealed weak antiferromagnetic exchange mediated by the saltrz anions with much larger D-parameter (|D|≫|J|).

  19. Mechanochemical effect in the iron(III) spin crossover complex [Fe(3-MeO-salenEt2]PF6 as studied by heat capacity calorimetry.

    PubMed

    Sorai, Michio; Burriel, Ramón; Westrum, Edgar F; Hendrickson, David N

    2008-04-10

    Magnetic and thermal properties of the iron(III) spin crossover complex [Fe(3MeO-salenEt)(2)]PF(6) are very sensitive to mechanochemical perturbations. Heat capacities for unperturbed and differently perturbed samples were precisely determined by adiabatic calorimetry at temperatures in the 10-300 K range. The unperturbed compound shows a cooperative spin crossover transition at 162.31 K, presenting a hysteresis of 2.8 K. The anomalous enthalpy and entropy contents of the transition were evaluated to be Delta(trs)H = 5.94 kJ mol(-1) and Delta(trs)S = 36.7 J K(-1) mol(-1), respectively. By mechanochemical treatments, (1) the phase transition temperature was lowered by 1.14 K, (2) the enthalpy and entropy gains at the phase transition due to the spin crossover phenomenon were diminished to Delta(trs)H = 4.94 kJ mol(-1) and Delta(trs)S = 31.1 J K(-1) mol(-1), and (3) the lattice heat capacities were larger than those of the unperturbed sample over the whole temperature range. In spite of different mechanical perturbations (grinding with a mortar and pestle and grinding in a ball-mill), two sets of heat capacity measurements provided basically the same results. The mechanochemical perturbation exerts its effect more strongly on the low-spin state than on the high-spin state. It shows a substantial increase of the number of iron(III) ions in the high-spin state below the transition temperature. The heat capacities of the diamagnetic cobalt(III) analogue [Co(3MeO-salenEt)(2)]PF(6) also were measured. The lattice heat capacity of the iron compounds has been estimated from either the measurements on the cobalt complex using a corresponding states law or the effective frequency distribution method. These estimations have been used for the evaluation of the transition anomaly.

  20. Selective oxidation catalysts obtained by immobilization of iron(III) porphyrins on thiosalicylic acid-modified Mg-Al layered double hydroxides.

    PubMed

    de Freitas Castro, Kelly Aparecida Dias; Wypych, Fernando; Antonangelo, Ariana; Mantovani, Karen Mary; Bail, Alesandro; Ucoski, Geani Maria; Ciuffi, Kátia Jorge; Cintra, Thais Elita; Nakagaki, Shirley

    2016-09-15

    Nitrate-intercalated Mg-Al layered double hydroxides (LDHs) were synthesized and exfoliated in formamide. Reaction of the single layer suspension with thiosalicylic acid under different conditions afforded two types of solids: LDHA1, in which the outer surface was modified with the anion thiosalicylate, and LDHA2, which contained the anion thiosalicylate intercalated between the LDH layers. LDHA1 and LDHA2 were used as supports to immobilize neutral (FeP1 and FeP2) and anionic (FeP3) iron(III) porphyrins. For comparison purposes, the iron(III) porphyrins (FePs) were also immobilized on LDH intercalated with nitrate anions obtained by the co-precipitation method. Chemical modification of LDH facilitated immobilization of the FePs through interaction of the functionalizing groups in LDH with the peripheral substituents on the porphyrin ring. The resulting FePx-LDHAy solids were characterized by X-ray diffraction (powder) and UV-Vis and EPR spectroscopies and were investigated as catalysts in the oxidation of cyclooctene and cyclohexane. The immobilized neutral FePs and their homogeneous counterparts gave similar product yields in the oxidation of cyclooctene, suggesting that immobilization of the FePs on the thiosalicylate-modified LDHs only supported the catalyst species without interfering in the catalytic outcome. On the other hand, in the oxidation of cyclohexane, the thiosalicylate anions on the outer surface of LDHA1 or intercalated between the LDHA2 layers influenced the catalytic activity of FePx-LDHAy, leading to different efficiency and selectivity results. FeP1-LDHA2 performed the best (29.6% alcohol yield) due to changes in the polarity of the surface of the support and the presence of FeP1. Interestingly, FeP1 also performed better in solution as compared to the other FePs. Finally, it was possible to recycle FeP1-LDHA2 at least three times.

  1. Catalytic efficiency of iron(III) oxides in decomposition of hydrogen peroxide: competition between the surface area and crystallinity of nanoparticles.

    PubMed

    Hermanek, Martin; Zboril, Radek; Medrik, Ivo; Pechousek, Jiri; Gregor, Cenek

    2007-09-05

    Various iron(III) oxide catalysts were prepared by controlled decomposition of a narrow layer (ca. 1 mm) of iron(II) oxalate dihydrate, FeC(2)O(4).2H(2)O, in air at the minimum conversion temperature of 175 degrees C. This thermally induced solid-state process allows for simple synthesis of amorphous Fe(2)O(3) nanoparticles and their controlled one-step crystallization to hematite (alpha-Fe(2)O(3)). Thus, nanopowders differing in surface area and particle crystallinity can be produced depending on the reaction time. The phase composition of iron(III) oxides was monitored by XRD and (57)Fe Mössbauer spectroscopy including in-field measurements, providing information on the relative contents of amorphous and crystalline phases. The gradual changes in particle size and surface area accompanying crystallization were evaluated by HRTEM and BET analysis, respectively. The catalytic efficiency of the synthesized nanoparticles was tested by tracking the decomposition of hydrogen peroxide. The obtained kinetic data gave an unconventional nonmonotone dependence of the rate constant on the surface area of the samples. The amorphous nanopowder with the largest surface area of 401 m(2) g(-1) revealed the lowest catalytic efficiency, while the highest efficiency was achieved with the sample having a significantly lower surface area, 337 m(2) g(-1), exhibiting a prevailing content of crystalline alpha-Fe(2)O(3) phase. The obtained rate constant, 26.4 x 10(-3) min(-1) (g/L)(-1), is currently the highest value published. The observed rare catalytic phenomenon, where the particle crystallinity prevails over the surface area effects, is discussed with respect to other processes of heterogeneous catalysis.

  2. The ground states of iron(III) porphines: role of entropy-enthalpy compensation, Fermi correlation, dispersion, and zero-point energies.

    PubMed

    Kepp, Kasper P

    2011-10-01

    Porphyrins are much studied due to their biochemical relevance and many applications. The density functional TPSSh has previously accurately described the energy of close-lying electronic states of transition metal systems such as porphyrins. However, a recent study questioned this conclusion based on calculations of five iron(III) porphines. Here, we compute the geometries of 80 different electronic configurations and the free energies of the most stable configurations with the functionals TPSSh, TPSS, and B3LYP. Zero-point energies and entropy favor high-spin by ~4kJ/mol and 0-10kJ/mol, respectively. When these effects are included, and all electronic configurations are evaluated, TPSSh correctly predicts the spin of all the four difficult phenylporphine cases and is within the lower bound of uncertainty of any known theoretical method for the fifth, iron(III) chloroporphine. Dispersion computed with DFT-D3 favors low-spin by 3-53kJ/mol (TPSSh) or 4-15kJ/mol (B3LYP) due to the attractive r(-6) term and the shorter distances in low-spin. The very large and diverse corrections from TPSS and TPSSh seem less consistent with the similarity of the systems than when calculated from B3LYP. If the functional-specific corrections are used, B3LYP and TPSSh are of equal accuracy, and TPSS is much worse, whereas if the physically reasonable B3LYP-computed dispersion effect is used for all functionals, TPSSh is accurate for all systems. B3LYP is significantly more accurate when dispersion is added, confirming previous results.

  3. Direct observation by laser scanning confocal microscopy of microstructure and phase migration of PVC gels in an applied electric field.

    PubMed

    Xia, Hong; Ueki, Takamitsu; Hirai, Toshihiro

    2011-02-01

    The fluorescent probe lucigenin was incorporated in poly(vinyl chloride) (PVC) gels, and laser scanning confocal microscopy (LSCM) was used to clarify the internal structures of the gels. From the two-dimensional and three-dimensional information by LSCM, we first observed the internal structure of the PVC gel at a wet status, where the PVC gels comprised a polymer-rich phase and a polymer-poor phase uniformly with a three-dimensional network structure. After an electric field was applied, an effect of the electric field resulted in the change of internal structure in the gels. The polymer-poor phase moved from the cathode to the anode and the polymer-rich phase formed linelike arrangement between electrodes due to the attraction force. On the other hand, the freeze-dried PVC gels with/without in-situ dc voltage casting were particularly fabricated to confirm above results by the field emission scanning electron microscopy (FE-SEM). It was found that many craters remained on the surface of the gel near the anode due to sublimation in freeze-drying. This phenomenon did not appear on the surface near the cathode. The results of in-situ dc voltage casting also suggested that a substantial amount of polymer-poor phase was moved and fixed at the anode. Thus, results of both LSCM and in-situ dc voltage casting corresponded to the effect of electric field on PVC gels and provided a convincing evidence for the interpretation of the deformation mechanism of PVC gel actuators by an applied electric field.

  4. Luminescence of Zn2L2- and PVC-based organic molecular compositions under photo- and electroexcitation

    NASA Astrophysics Data System (ADS)

    Eremina, N. S.; Degtyarenko, K. M.; Gadirov, R. M.; Kopylova, T. N.; Mayer, G. V.; Samsonova, L. G.; Shul'Gin, V. F.; Gusev, A. N.; Meshkova, S. B.; Usachev, D. N.

    2010-10-01

    Spectral and luminescent properties of Zn2L2 complex {mu-2-bis((3-pyridine-2-il)-5-(2-salicyldeniminophenyl)-1,2,4-triaurum(2-))dizinc(2+)solvate with ethanol} are investigated in solutions, powder, and thin polyvinylcarbazole (PVC) films. The trends in their change versus the nature, aggregate state, and excitation method are established. Electroluminescence (λmax = 493 nm) of an ITO/PEDOT/PVC: Zn2L2/LiF/CaMg/Ag device is excited, and its current-voltage and brightness-voltage characteristics are investigated.

  5. On the Surface Free Energy of PVC/EVA Polymer Blends: Comparison of Different Calculation Methods.

    PubMed

    Michalski; Hardy; Saramago

    1998-12-01

    The surface free energy of polymeric films of polyvinylchloride (PVC) + poly(ethylene-co-vinylacetate) (EVA) blends was calculated using the van Oss treatment (Lifshitz and electron donor-electron acceptor components of surface free energy) and the Owens-Wendt treatment (dispersive and nondispersive components of surface free energy). Surface free energy results were found to be greatly dependent on the calculation method and on the number of standard liquids used for contact angle measurements. The nondispersive/donor-acceptor surface free energy component and the total surface free energy of polymeric films were always higher when the van Oss treatment was used compared to the Owens-Wendt treatment. Conversely, both methods led to similar apolar/Lifshitz components. All the calculation methods were in good agreement for the surface free energy of PVC; however, a discrepancy between the methods arose as EVA content in the blends increased. It seems that there is not yet a definite solution for the calculation of solid surface free energy. Further developments of existing models are needed in order to gain consistency when calculating this important physicochemical quantity. Copyright 1998 Academic Press.

  6. Formation of monomer residues in PS, PC, PA-6 and PVC upon γ-irradiation

    NASA Astrophysics Data System (ADS)

    Young Park, Gun; Yong Cho, Seung; Hoon Jeon, Dae; Shin Kwak, In; Ho Lee, Kwang; Park, H. J.

    2006-09-01

    Food packaging polymers, polystyrene (PS), polycarbonate (PC), polyamide-6 (PA-6), and polyvinylchloride (PVC), were irradiated with dose in the range 5-200 kGy. The quantities of corresponding monomer residues (styrene monomer, bisphenol-A, ɛ-caprolactam, vinyl chloride) released from target materials were analyzed using a SIM mode of GC/MSD. Styrene monomer in PS showed a slight increase from 740 to 777 ppm at 5-30 kGy and then decreased as the dose increased from 30 to 200 kGy. Bisphenol-A in PC was dose independent at the low doses, 5, 10 and 30 kGy, but its level increased from 173 to 473 ppm at 30 kGy and thereafter remained unchanged through 200 kGy. ɛ-Caprolactam in PA-6 was also dose independent, in the range of 5-200 kGy, but its level (122-164 ppm) was found to be higher than those (71 ppm) of non-irradiated sample. As for PVC, the quantity of vinyl chloride tended to increase from 8 to 18 ppm at 5-200 kGy.

  7. Chlorine behavior during co-hydrothermal treatment of high alkali coal and PVC

    NASA Astrophysics Data System (ADS)

    Huang, N.; Zhao, P. T.; Li, Z. Z.; Li, T.

    2016-08-01

    The hydrothermal treatment (HT) is an effective method to remove chlorine from chlorinated wastes under mild conditions. However, the alkali was required to improve the dechlorination efficiency. Meanwhile, the alkalis contents removed was necessary to realize the clean and highly efficient utilization of coal. This work was trying to investigate the feasibility of simultaneously removal alkalis and chlorine by co-hydrothermal treatment of PVC and high-alkali coal. The effect of operating conditions including the HT temperature, the holding time and particle sizes of coal on the dechlorination efficiency (DE) of PVC during the HT process was experimentally studied in this work. The results show that the DE increased with the rise of: 1) particle sizes (0.054~0.22mm), 2) holding time (30~90 min) and 3) temperature (240~300 °C). In detail, under 300 °C and 60min of holding time, the 85.18% of DE with first PS was lower than the 93.93% of DE with second PS and 100% of DE with third PS. The organic chlorine mainly transferred into chloridion in aqueous solution in HT process. All the results indicate that it is a prospective way to simultaneously removal alkalis and chlorine by co-hydrothermal treatment of chlorinated wastes and high-alkali coal.

  8. Radiation-induced modifications of PVC compounds stabilized with non-lead systems

    NASA Astrophysics Data System (ADS)

    Castañeda Facio, A.; Benavides Cantú, R.; Martínez Pardo, M. E.; Carrasco Abrego, H.

    2004-09-01

    The radiation crosslinking of polyvinyl chloride (PVC) formulated with two different stabilizer systems (Ca/Zn and dibasic lead phthalate) and trimethylolpropane trimethacrylate, a polyfunctional monomer, has been studied with the purpose of observing their behaviour and with the idea of replacing the lead stabilizer used in the typical wire and cable formulation for Ca/Zn systems. The compounds of PVC were irradiated by 60Co γ radiation at doses of 50, 75 and 100 kGy and two different atmospheres (argon and air). The dosimetry used to establish the irradiation times was carried out by both theoretical and experimental methods. The tensile test and gel measurements showed the highest values at 100 kGy although Young's Modulus showed that 75 kGy and argon atmosphere are optimum conditions for wire and cable formulations. The formulation with Ca/Zn stabiliser showed a very similar behaviour to the one made of lead, which, incidentally, produces high concentration of polyenes, in contrast to the Ca/Zn system.

  9. Volatile organic components migrating from plastic pipes (HDPE, PEX and PVC) into drinking water.

    PubMed

    Skjevrak, Ingun; Due, Anne; Gjerstad, Karl Olav; Herikstad, Hallgeir

    2003-04-01

    High-density polyethylene pipes (HDPE), crossbonded polyethylene pipes (PEX) and polyvinyl chloride (PVC) pipes for drinking water were tested with respect to migration of volatile organic components (VOC) to water. The odour of water in contact with plastic pipes was assessed according to the quantitative threshold odour number (TON) concept. A major migrating component from HDPE pipes was 2,4-di-tert-butyl-phenol (2,4-DTBP) which is a known degradation product from antioxidants such as Irgafos 168(R). In addition, a range of esters, aldehydes, ketones, aromatic hydrocarbons and terpenoids were identified as migration products from HDPE pipes. Water in contact with HDPE pipes was assessed with respect to TON, and values > or =4 were determined for five out of seven brands of HDPE pipes. The total amount of VOC released to water during three successive test periods were fairly constant for the HDPE pipes. Corresponding migration tests carried out for PEX pipes showed that VOC migrated in significant amounts into the test water, and TON >/=5 of the test water were observed in all tests. Several of the migrated VOC were not identified. Oxygenates predominated the identified VOC in the test water from PEX pipes. Migration tests of PVC pipes revealed few volatile migrants in the test samples and no significant odour of the test water.

  10. Surface Modification of Poly Vinyl Chloride (PVC) Using Low Pressure Argon and Oxygen Plasma

    NASA Astrophysics Data System (ADS)

    Mahmood, Ghoranneviss; Sheila, Shahidi; Jakub, Wiener

    2010-04-01

    In this study, commercial poly vinyl chloride (PVC) films were treated by oxygen and argon plasmas in a cylindrical glass tube which was surrounded by a DC variable magnetic field, with different sample positions in the plasma reactor and also different exposure durations. Effects of the plasma treatment on the hydrophilic properties of the films were studied by measuring the water drop contact angle on the surface of the samples. The surface topography of the untreated and plasma treated films was analyzed and compared by atomic force microscopy (AFM). The optical characteristic changes in treated samples were investigated using reflective spectrophotometry. Also, the chemical changes which appeared on the surface of the samples were investigated using Fourier transform infrared spectroscopy (FTIR). The results show that the plasma treated PVC becomes more hydrophilic with an enhanced wettability. A sharp decrease in the water contact angle may also be a consequence of the surface texturization. The aging effect on wettability of the samples was also investigated. The results show that the effect of oxygen plasma on the surface properties of the samples is more pronounced compared with that of argon plasma.

  11. Determination of additives in PVC material by UV laser ablation inductively coupled plasma atomic emission spectrometry

    NASA Astrophysics Data System (ADS)

    Hemmerlin, M.; Mermet, J. M.; Bertucci, M.; Zydowicz, P.

    1997-04-01

    UV laser ablation inductively coupled plasma atomic emission spectrometry (LA-ICP-AES) has been applied to the direct determination of additives in solid poly(vinyl chloride) materials. A Nd:YAG laser, operating at its fourth harmonic (266 nm), was used with a beam masking device, in the most reproducible conditions, to introduce solid particles into the plasma torch of a simultaneous ICP-AES system. Emphasis was placed on both precision and accuracy in the analysis of PVC materials by LA-ICP-AES. A series of six in-house PVC reference materials was prepared by incorporating several additives in increasing concentrations. Three alternative methods were evaluated to certify the amount of incorporated elements: ICP-AES with sample dissolution, NAA and XRF. Satisfactory results and good agreement were obtained for seven elements (Al, Ca, Cd, Mg, Sb, Sn and Ti) among the ten incorporated. Sample homogeneity appeared to be satisfactory, and calibration graphs obtained by LA-ICP-AES for several elements are presented. Finally, the performance of the technique in terms of repeatability (1.6-5%), reproducibility (2-5%), and limits of detection was investigated.

  12. Removal of aniline from aqueous solution by PVC-CDAE ligand-exchanger.

    PubMed

    Gürten, A Ali; Uçan, Selma; Ozler, M Ali; Ayar, Ahmet

    2005-04-11

    The adsorption of aniline from aqueous solutions onto cobalt(II)-poly(vinyl chloride)-carboxylated diaminoethane (PVC-CDAE) resin has been studied using a mini-column apparatus at 25+/-0.1 degrees C. First of all, experimental data obtained from the breakthrough curves were tested by using the Scatchard plot analysis, to have a preliminary prediction about the types of interaction of the resin with aniline. Our aim was to determine the model which best describes the experimental data. The aspect of the Scatchard plot indicated that the aniline adsorption did not follow the Langmuir model and the presence of two types of binding sites for aniline on the resin. However, the dynamics of aniline uptake were represented by the Freundlich model reasonably well. The kinetics of aniline adsorption from aqueous solution on the cobalt(II)-PVC-CDAE have also been tested using continuous column runs and rate-controlling step of the process was determined. In this study, homogeneous diffusion model was adapted to a column system to describe the change in the aniline concentration at the column exit beginning from breakthrough point as a function of time. Kinetic studies revealed that the rate-controlling step of the aniline adsorption was predominately film diffusion controlled rather particle diffusion.

  13. Industrial hygiene evaluation of thermal degradation products from PVC film in meat-wrapping operations.

    PubMed

    Cook, W A

    1980-07-01

    An industrial hygiene evaluation is presented concerning experimental data included in the preceding paper on thermal degradation products from hot-wire and "cool"-rod cutting of PVC film but, in this paper, limited to film used in meat-wrapping operations. Room air concentrations of less than 0.2 ppm HCl and less than 0.05 ppm benzene can be maintained by a number of factors, including minimal dilution ventilation. Estimates of room air concentrations of degradation products are presented using average values of amounts produced per cut. The relation of these concentrations to TLV's is given, together with methods of suggesting TLV's for substances not listed by ACGIH or OSHA. Room air concentrations for the 12 degradation products for which TLV's are assigned, based on average values per cut, were no greater than 0.3% of accepted limits. Room air concentrations of DOA are not determinable from available data but present information does not indicate that exposure to DOA causes airway hyperreactivity. The cool rod, rather than the hot wire, is recommended as good industrial hygiene practice, producing no apparent PVC degradation products, even though similar amounts of DOA are volatilized.

  14. Recovery of copper from PVC multiwire cable waste by steam gasification.

    PubMed

    Zabłocka-Malicka, Monika; Rutkowski, Piotr; Szczepaniak, Włodzimierz

    2015-12-01

    Screened multiwire, PVC insulated tinned copper cable was gasified with steam at high temperature (HTSG) under atmospheric pressure for recovery of cooper. Gases from the process were additionally equilibrated at 850°C on the bed of calcined clay granules and more than 98% of C+H content in the cable was transformed to non-condensing species. Granules prepared from local clay were generally resistant for chlorination, there was also almost no deposition of metals, Cu and Sn, on the catalytic bed. It was found that 28% of chlorine reacted to form CaCl2, 71% was retained in aqueous condensate and only 0.6% was absorbed in alkaline scrubber. More than 99% of calcium existed in the process solid residue as a mixture of calcium chloride and calcium oxide/hydroxide. PVC and other hydrocarbon constituents were completely removed from the cable sample. Copper was preserved in original form and volatilization of copper species appeared insignificant. Tin was alloying with copper and its volatilization was less than 1%. Fractionation and speciation of metals, chlorine and calcium were discussed on the basis of equilibrium model calculated with HSC Chemistry software. High temperature steam gasification prevents direct use of the air and steam/water is in the process simultaneously gaseous carrier and reagent, which may be recycled together with hydrocarbon condensates.

  15. Preparation and characterization of polymer nanocomposites based on PVDF/PVC doped with graphene nanoparticles

    NASA Astrophysics Data System (ADS)

    Elashmawi, I. S.; Alatawi, Naifa S.; Elsayed, Nadia H.

    Novel nanocomposites based on PVDF/PVC blend containing graphene oxide nanoparticles (GO) were prepare using sonicator. IR analysis revealed that the addition of GO prompts a crystal transformation of α-phase of PVDF. The change of the structural before and after adding GO to PVDF/PVC were studied by X-ray diffraction. A decrease in activation energy gap from UV data was observed with increasing GO content, implying a variation of reactivity as a result of reaction extent. The variation of ε‧ with frequency is nearly the same as that of ε″ . At higher frequencies, the decrease of both ε‧ and ε″ becomes nearly constant. The dispersion at lower frequencies ε‧ of ε‧ polarization is of Maxwell-Wagner interfacial polarization but at higher frequencies, it levels off. The behavior of conductivity (σAC) tends to acquire constant values approaching it DC values. The values of σAC was increased after doped GO with exponential increase after the critical value of frequency. All nanocomposites behaved the same fashion revealing that a higher number of polarons were getting added to conducting pool in composites as graphene content was increased. Conduction mechanism appeared to be getting expedited with increasing frequency due to fact that increase in frequency enhances polaron hopping frequency.

  16. Preparation and characterization of PVC-LiClO 4 based composite polymer electrolyte

    NASA Astrophysics Data System (ADS)

    Ahmad, A.; Rahman, M. Y. A.; Su'ait, M. S.

    2008-11-01

    The preparation of PVC-LiClO 4 based composite polymer electrolyte was carried out to study the effect of ceramic fillers such as ZnO, TiO 2 and Al 2O 3 on the room temperature conductivity. The samples were tested using impedance spectroscopy, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). The samples were prepared with different percentage (%) by weight of ceramic filler. The highest ionic conductivity achieved was 3.7×10 -7 S cm -1 for the sample prepared with 20% of ZnO. The glass transition temperature decreases with the fillers concentration due to the increasing amorphous state. While, the decomposition temperature increases with the increase in the fillers content. Both of these thermal properties influence the enhancement of the conductivity value. The morphology of the samples shows the even distribution of the ceramic filler in the samples however the filler starts to agglomerate in the sample at higher concentration of filler. In conclusion, the addition of ceramic filler improves the ionic conductivity of PVC-LiCIO 4 composite polymer electrolyte.

  17. The effect of white or grey PVC pipe and its joint solvents (primer and cement) on odour problems in drinking water distribution systems.

    PubMed

    Wiesenthal, K E; Suffet, I H

    2007-01-01

    A study of the production of odour-causing compounds was conducted from the leaching of polyvinylchloride (PVC) pipe and its joints, primer and cement, into drinking water distribution systems. Flavour Profile Analysis (FPA), closed-loop stripping analysis--gas chromatography/mass spectrometry (CLSA-GC/MS) and sensory-GC analysis of white or grey PVC alone found no odour-causing compounds produced during the leaching experiments. FPA analysis of the PVC's primer and cement leached alone and/or when applied to grey or white PVC pipes produced a glue/varnish odour. A sweet/phenolic odour replaced the glue/varnish odour after the leached media were diluted with Milli-Q water to threshold odour intensity. Three compounds were responsible for the sweet/phenolic odour and were observed by sensoryGC analysis. The leaching study of the PVC pipe with its joint solvents (primer and cement) concluded that the original solvent compounds, and their reaction products that formed during the bonding process on the PVC pipe, were a primary source of the glue/varnish odour. The original compounds of the PVC primer and cement were not detected by CLSA-GC/MS, due to their high volatility during the CLSA extraction method and/or these compounds appeared in a solvent peak of the GC/MS analysis. However, the original primer and cement chemicals (acetone, tetrahydrofuran, methyl ethyl ketone, and cyclohexanone) had a glue/varnish odour. A total of nine odorous GC peaks were produced as reaction products from leaching of primer in water and white or grey PVC pipe with primer and cement, and white or grey PVC with primer only. None of these compounds were among the chemical ingredients in the original primer or cement. Four GC peaks with a sweet/phenolic odour were present due to the reaction products of the cement leached with white or grey PVC. None of these compounds were positively identified.

  18. Surface morphology changes of polymer membrane and carbon paste sertraline sensors.

    PubMed

    Khater, M M; Hassib, H B; Issa, Y M; Mohammed, S H

    2015-03-01

    Polymer membrane and chemically modified carbon paste (CMCP) sensors for determination of sertraline HCl (Ser-Cl) incorporating sertraline tetraphenylborate (Ser-TPB) as an electro-active material were constructed. They showed a rapid and linear response for Ser-ion over the concentration range 0.01-10.00 mmol L(-1). The limits of detection were 2.80 and 9.55 μmol L(-1), and Nernastian slopes were 56.60, 59.60 mV decade(-1) for membrane and CMCP sensors for batch method. In flow injection analysis (FIA), the electrodes revealed comparatively good selectivity for Ser-ion with regard to a wide variety of different cations, sugars, and amino acids. The addition of different anionic additives, namely sodium tetraphenylborate (NaTPB), potassium tetraphenylborate (KTPB), potassium tetrakis[3,5-bis-(triflouromethyl)phenyl]borate (KTFMPB), and sodium tetrakis[3,5-bis(trifluoro-methyl)phenyl]borate (NaTFMPB), to the prepared mixture improved their response characteristics. The surface morphologies of membrane films containing PVC only (blank), plasticizer+PVC, Ser-TPB+plasticizer+PVC, and Ser-TPB +plasticizer+PVC+additive were studied using scanning and atomic force electron microscopes. These sensors had been used in the potentiometric titration of Ser-ion against NaTPB. Standard addition method for the pure raw material and some of its pharmaceutical tablets was used for Ser-Cl determination. The obtained results were tested for their repeatability and reproducibility and were statistically treated by F- and t- tests.

  19. Behaviour of Steel Arch Stabilized by a Textile Membrane

    NASA Astrophysics Data System (ADS)

    Svoboda, O.; Machacek, J.

    2015-11-01

    Behaviour of the slender steel arch supporting textile membranes in a membrane structure with respect to in-plane and out-of plane stability is investigated in the paper. In the last decades the textile membranes have been widely used to cover both common and exclusive structures due to progress in new membrane materials with eminent properties. Nevertheless, complex analysis of such membranes in interaction with steel structure (carbon/stainless steel perimeter or supporting elements) is rather demanding, even with specialized software. Laboratory model of a large membrane structure simulating a shelter roof of a concert stage was tested and the resulting stress/deflection values are presented. The model of a reasonable size was provided with prestressed membrane of PVC coated polyester fabric Ferrari® Précontraint 702S and tested under various loadings. The supporting steel structure consisted of two steel arch tubes from S355 grade steel and perimeter prestressed cables. The stability behaviour of the inner tube was the primary interest of the investigation. The SOFiSTiK software was used to analyse the structural behaviour in 3D. Numerical non-linear analysis of deflections and internal forces of the structure under symmetrical and asymmetrical loadings covers various membrane prestressing and specific boundary conditions. The numerical results are validated using test results. Finally, the preliminary recommendations for appropriate numerical modelling and stability design of the supporting structure are presented.

  20. Multicomponent membranes

    DOEpatents

    Kulprathipanja, Santi; Kulkarni, Sudhir S.; Funk, Edward W.

    1988-01-01

    A multicomponent membrane which may be used for separating various components which are present in a fluid feed mixture comprises a mixture of a plasticizer such as a glycol and an organic polymer cast upon a porous organic polymer support. The membrane may be prepared by casting an emulsion or a solution of the plasticizer and polymer on the porous support, evaporating the solvent and recovering the membrane after curing.

  1. [Study of the response characteristics of PVC membrane ion-associate type electrodes for organic base cations].

    PubMed

    Kang, X J; Wang, C Y

    1990-01-01

    A new type of ISEs which only uses alkaloid precipitants in place of ion pairs as active materials in polyvinyl chloride was recommended. The characteristics of the electrodes sensing over ten kinds of organic bases have been studied in comparison with those based on ion pairs. It can be concluded that the response characteristics of ion-associate type ISEs depend on the strength of the association between ion-exchange site and principal ions. Visual turbidimetry was used to select active materials for ISEs in advance. Among six alkaloid precipitants (silicotungstic acid, tetraphenyl borate, dipicrylamine, picric acid, picrolonic acid and Reineckate), silicotungstic acid is the most active material for ion-associate type organic base cation ISEs. With it, the sensor has wider Nernst linearity and lower detection limit than some ion pair based ones in literature.

  2. High efficiency chlorine removal from polyvinyl chloride (PVC) pyrolysis with a gas-liquid fluidized bed reactor.

    PubMed

    Yuan, G; Chen, D; Yin, L; Wang, Z; Zhao, L; Wang, J Y

    2014-06-01

    In this research a gas-liquid fluidized bed reactor was developed for removing chlorine (Cl) from polyvinyl chloride (PVC) to favor its pyrolysis treatment. In order to efficiently remove Cl within a limited time before extensive generation of hydrocarbon products, the gas-liquid fluidized bed reactor was running at 280-320 °C, where hot N2 was used as fluidizing gas to fluidize the molten polymer, letting the molten polymer contact well with N2 to release Cl in form of HCl. Experimental results showed that dechlorination efficiency is mainly temperature dependent and 300 °C is a proper reaction temperature for efficient dechlorination within a limited time duration and for prevention of extensive pyrolysis; under this temperature 99.5% of Cl removal efficiency can be obtained within reaction time around 1 min after melting is completed as the flow rate of N2 gas was set around 0.47-0.85 Nm(3) kg(-1) for the molten PVC. Larger N2 flow rate and additives in PVC would enhance HCl release but did not change the final dechlorination efficiency; and excessive N2 flow rate should be avoided for prevention of polymer entrainment. HCl is emitted from PVC granules or scraps at the mean time they started to melt and the melting stage should be taken into consideration when design the gas-liquid fluidized bed reactor for dechlorination.

  3. An organotin mixture found in polyvinyl chloride (PVC) pipe is not immunotoxic to adult Sprague-Dawley rats.

    PubMed

    DeWitt, Jamie C; Copeland, Carey B; Luebke, Robert W

    2008-01-01

    Organotin compounds used in polyvinyl chloride (PVC) pipe production are of concern to the U.S. Environmental Protection Agency (EPA) because they leach from supply pipes into drinking water and are reported multisystem toxicants. Immune function was assessed in male Sprague-Dawley rats exposed to the mixture of organotins used in PVC pipe production. Although several of these organotins are reported immunotoxicants, their immunotoxicity as a mixture when given by drinking water has not been evaluated. Adult male rats were given drinking water for 28 d containing a mixture of dibutyltin dichloride (DBTC), dimethyltin dichloride (DMTC), monobutyltin trichloride (MBT), and monomethyltin trichloride (MMT) in a 2:2:1:1 ratio, respectively, at 3 different concentrations (5:5:2.5:2.5, 10:10:5:5, or 20:20:10:10 mg organotin/L), MMT alone (20 or 40 mg MMT/L), or plain water as a control. Delayed-type hypersensitivity, antibody synthesis, and natural killer cell cytotoxicity were evaluated in separate endpoint groups (n = 8/dose; 24/endpoint) immediately after exposure ended. The evaluated immune functions were not affected by the mixture or by MMT alone. Our data suggest that immunotoxicity is unlikely to result from the concentration of organotins present in drinking water delivered via PVC pipes, as the concentrations used were several orders of magnitude higher than those expected to leach from PVC pipes.

  4. Roles of ionic strength and biofilm roughness on adhesion kinetics of Escherichia coli onto groundwater biofilm grown on PVC surfaces.

    PubMed

    Janjaroen, Dao; Ling, Fangqiong Q; Ling, Fangqiong; Monroy, Guillermo; Derlon, Nicolas; Morgenroth, Eberhard; Mogenroth, Eberhard; Boppart, Stephen A; Liu, Wen-Tso; Nguyen, Thanh H

    2013-05-01

    Mechanisms of Escherichia coli attachment on biofilms grown on PVC coupons were investigated. Biofilms were grown in CDC reactors using groundwater as feed solution over a period up to 27 weeks. Biofilm physical structure was characterized at the micro- and meso-scales using Scanning Electron Microscopy (SEM) and Optical Coherence Tomography (OCT), respectively. Microbial community diversity was analyzed with Terminal Restricted Fragment Length Polymorphism (T-RFLP). Both physical structure and microbial community diversity of the biofilms were shown to be changing from 2 weeks to 14 weeks, and became relatively stable after 16 weeks. A parallel plate flow chamber coupled with an inverted fluorescent microscope was also used to monitor the attachment of fluorescent microspheres and E. coli on clean PVC surfaces and biofilms grown on PVC surfaces for different ages. Two mechanisms of E. coli attachment were identified. The adhesion rate coefficients (kd) of E. coli on nascent PVC surfaces and 2-week biofilms increased with ionic strength. However, after biofilms grew for 8 weeks, the adhesion was found to be independent of solution chemistry. Instead, a positive correlation between kd and biofilm roughness as determined by OCT was obtained, indicating that the physical structure of biofilms could play an important role in facilitating the adhesion of E. coli cells.

  5. Roles of ionic strength and biofilm roughness on adhesion kinetics of Escherichia coli onto groundwater biofilm grown on PVC surfaces

    PubMed Central

    Janjaroen, Dao; Ling, Fangqiong; Monroy, Guillermo; Derlon, Nicolas; Mogenroth, Eberhard; Boppart, Stephen A.; Liu, Wen-Tso; Nguyen, Thanh H.

    2013-01-01

    Mechanisms of Escherichia coli attachment on biofilms grown on PVC coupons were investigated. Biofilms were grown in CDC reactors using groundwater as feed solution over a period up to 27 weeks. Biofilm physical structure was characterized at the micro- and meso-scales using Scanning Electron Microscopy (SEM) and Optical Coherence Tomography (OCT), respectively. Microbial community diversity was analyzed with Terminal Restricted Fragment Length Polymorphism (T-RFLP). Both physical structure and microbial community diversity of the biofilms were shown to be changing from 2 weeks to 14 weeks, and became relatively stable after 16 weeks. A parallel plate flow chamber coupled with an inverted fluorescent microscope was also used to monitor the attachment of fluorescent microspheres and E. coli on clean PVC surfaces and biofilms grown on PVC surfaces for different ages. Two mechanisms of E. coli attachment were identified. The adhesion rate coefficients (kd) of E. coli on nascent PVC surfaces and 2-week biofilms increased with ionic strength. However, after biofilms grew for 8 weeks, the adhesion was found to be independent of solution chemistry. Instead, a positive correlation between kd and biofilm roughness as determined by OCT was obtained, indicating that the physical structure of biofilms could play an important role in facilitating the adhesion of E. coli cells. PMID:23497979

  6. Photocatalytic and antibacterial properties of medical-grade PVC material coated with TiO2 film.

    PubMed

    Lin, Huaxiang; Xu, Ziting; Wang, Xuxu; Long, Jinlin; Su, Wenyue; Fu, Xianzhi; Lin, Qun

    2008-11-01

    The TiO(2) film was coated on poly vinyl chloride (PVC) surface by dip-coating process from TiO(2)-PVC-THF suspension. The morphology and crystal structure of the as-synthesized samples were characterized by SEM and XRD. The photocatalytic properties were measured by the photodegradation reaction of RhB and the anti-adhesion and anti-bacteria for Escherichia coli. The results show that the resultant TiO(2) film is well-conglutinated on PVC surface and has the same crystal structure as the original TiO(2) powder. The TiO(2)/PVC shows excellent photocatalytic activity for the degradation of aqueous RhB and the activity increases with increasing reaction time and tends toward stable after accumulative illumination for 11.5 h. The TiO(2) film shows good bacterial anti-adhesion activity following photo-activation and sterilization property under UV irradiation. The E. coli can be killed completely after UV irradiation for 1.5 h.

  7. Radiation-grafted, chemically modified membranes part I - Synthesis of a selective aluminum material

    NASA Astrophysics Data System (ADS)

    Bazante-Yamaguishi, Renata; Moura, Eduardo; Manzoli, José E.; Geraldo, Aurea B. C.

    2014-01-01

    Polymeric membranes were styrene grafted by irradiation methods and the obtained material was chemically modified to become aluminum selective. For this purpose, polymeric substrates of PVC (polyvinyl chloride) and PP (polypropylene) were styrene grafted mutually by gamma and electron beam irradiation. The modification process includes three basic reaction paths: Friedel-Crafts acylation, 2-methylanisole coupling and a final oxidation to achieve aluminum selectivity. Although this specific chemical modification in derivatives of polystyrene is not new, the new challenge is to obtain a selective material where original membrane characteristics (physical shape and mechanical resistance) are minimally conserved after such an aggressive treatment.

  8. Forensic utility of carbon isotope ratio variations in PVC tape backings.

    PubMed

    Dietz, Marianne E; Stern, Libby A; Mehltretter, Andria Hobbs; Parish, Ashley; McLasky, Velvet; Aranda, Roman

    2012-03-01

    Forensic interest in adhesive tapes with polyvinyl chloride (PVC) backings (electrical tape) derives from their use in a variety of illicit activities. Due to the range of physical characteristics, chemical compositions, and homogeneity within a single roll of tape, traditional microscopic and chemical analyses can offer a high degree of discrimination between tapes, permitting the assessment of potential associations between evidentiary tape samples. The carbon isotope ratios of tapes could provide additional discrimination among tape samples. To evaluate whether carbon isotope ratios may be able to increase discrimination of electrical tapes, particularly with regards to different rolls of tape of the same product, we assessed the δ(13)C values of backings from 87 rolls of PVC-based black electrical tape (~20 brands, >60 products) Prior to analysis, adhesives were removed to prevent contamination by adhering debris, and plasticizers were extracted because of concern over their potential mobility. This result is consistent with each of these tapes having approximately the same plasticizer δ(13)C value and proportion of carbon in these plasticizers. The δ(13)C values of the 87 PVC tape backings ranged between -23.5 and -41.3 (‰, V-PDB), with negligible carbon isotopic variation within single rolls of tape, yet large variations among tape brands and tape products. Within this tape population, carbon isotope ratios permitted an average exclusion power of 93.7%, using a window of +/-0.3‰; the combination of carbon isotope ratio measurement with additional chemical and physical analyses raises the discrimination power to over 98.9%, with only 41 out of a possible 3741 pairs of tape samples being indistinguishable. There was a linear relationship between the δ(13)C value of tape backings and the change in δ(13)C value with the extraction of plasticizers. Analyses of pre- and post-blast tape sample pairs show that carbon isotope signatures are within 0.3‰ of

  9. Discoloration of polyvinyl chloride (PVC) tape as a proxy for water-table depth in peatlands: validation and assessment of seasonal variability

    USGS Publications Warehouse

    Booth, Robert K.; Hotchkiss, Sara C.; Wilcox, Douglas A.

    2005-01-01

    Summary: 1. Discoloration of polyvinyl chloride (PVC) tape has been used in peatland ecological and hydrological studies as an inexpensive way to monitor changes in water-table depth and reducing conditions. 2. We investigated the relationship between depth of PVC tape discoloration and measured water-table depth at monthly time steps during the growing season within nine kettle peatlands of northern Wisconsin. Our specific objectives were to: (1) determine if PVC discoloration is an accurate method of inferring water-table depth in Sphagnum-dominated kettle peatlands of the region; (2) assess seasonal variability in the accuracy of the method; and (3) determine if systematic differences in accuracy occurred among microhabitats, PVC tape colour and peatlands. 3. Our results indicated that PVC tape discoloration can be used to describe gradients of water-table depth in kettle peatlands. However, accuracy differed among the peatlands studied, and was systematically biased in early spring and late summer/autumn. Regardless of the month when the tape was installed, the highest elevations of PVC tape discoloration showed the strongest correlation with midsummer (around July) water-table depth and average water-table depth during the growing season. 4. The PVC tape discoloration method should be used cautiously when precise estimates are needed of seasonal changes in the water-table.

  10. Molecular Signatures for the PVC Clade (Planctomycetes, Verrucomicrobia, Chlamydiae, and Lentisphaerae) of Bacteria Provide Insights into Their Evolutionary Relationships.

    PubMed

    Gupta, Radhey S; Bhandari, Vaibhav; Naushad, Hafiz Sohail

    2012-01-01

    The PVC superphylum is an amalgamation of species from the phyla Planctomycetes, Verrucomicrobia, and Chlamydiae, along with the Lentisphaerae, Poribacteria, and two other candidate divisions. The diverse species of this superphylum lack any significant marker that differentiates them from other bacteria. Recently, genome sequences for 37 species covering all of the main PVC groups of bacteria have become available. We have used these sequences to construct a phylogenetic tree based upon concatenated sequences for 16 proteins and identify molecular signatures in protein sequences that are specific for the species from these phyla or those providing molecular links among them. Of the useful molecular markers identified in the present work, six conserved signature indels (CSIs) in the proteins Cyt c oxidase, UvrD helicase, urease, and a helicase-domain containing protein are specific for the species from the Verrucomicrobia phylum; three other CSIs in an ABC transporter protein, cobyrinic acid ac-diamide synthase, and SpoVG protein are specific for the Planctomycetes species. Additionally, a 3 aa insert in the RpoB protein is uniquely present in all sequenced Chlamydiae, Verrucomicrobia, and Lentisphaerae species, providing evidence for the shared ancestry of the species from these three phyla. Lastly, we have also identified a conserved protein of unknown function that is exclusively found in all sequenced species from the phyla Chlamydiae, Verrucomicrobia, Lentisphaerae, and Planctomycetes suggesting a specific linkage among them. The absence of this protein in Poribacteria, which branches separately from other members of the PVC clade, indicates that it is not specifically related to the PVC clade of bacteria. The molecular markers described here in addition to clarifying the evolutionary relationships among the PVC clade of bacteria also provide novel tools for their identification and for genetic and biochemical studies on these organisms.

  11. Molecular Signatures for the PVC Clade (Planctomycetes, Verrucomicrobia, Chlamydiae, and Lentisphaerae) of Bacteria Provide Insights into Their Evolutionary Relationships

    PubMed Central

    Gupta, Radhey S.; Bhandari, Vaibhav; Naushad, Hafiz Sohail

    2012-01-01

    The PVC superphylum is an amalgamation of species from the phyla Planctomycetes, Verrucomicrobia, and Chlamydiae, along with the Lentisphaerae, Poribacteria, and two other candidate divisions. The diverse species of this superphylum lack any significant marker that differentiates them from other bacteria. Recently, genome sequences for 37 species covering all of the main PVC groups of bacteria have become available. We have used these sequences to construct a phylogenetic tree based upon concatenated sequences for 16 proteins and identify molecular signatures in protein sequences that are specific for the species from these phyla or those providing molecular links among them. Of the useful molecular markers identified in the present work, six conserved signature indels (CSIs) in the proteins Cyt c oxidase, UvrD helicase, urease, and a helicase-domain containing protein are specific for the species from the Verrucomicrobia phylum; three other CSIs in an ABC transporter protein, cobyrinic acid ac-diamide synthase, and SpoVG protein are specific for the Planctomycetes species. Additionally, a 3 aa insert in the RpoB protein is uniquely present in all sequenced Chlamydiae, Verrucomicrobia, and Lentisphaerae species, providing evidence for the shared ancestry of the species from these three phyla. Lastly, we have also identified a conserved protein of unknown function that is exclusively found in all sequenced species from the phyla Chlamydiae, Verrucomicrobia, Lentisphaerae, and Planctomycetes suggesting a specific linkage among them. The absence of this protein in Poribacteria, which branches separately from other members of the PVC clade, indicates that it is not specifically related to the PVC clade of bacteria. The molecular markers described here in addition to clarifying the evolutionary relationships among the PVC clade of bacteria also provide novel tools for their identification and for genetic and biochemical studies on these organisms. PMID:23060863

  12. Identification and quantification of 14 phthalates and 5 non-phthalate plasticizers in PVC medical devices by GC-MS.

    PubMed

    Gimeno, Pascal; Thomas, Sébastien; Bousquet, Claudine; Maggio, Annie-Françoise; Civade, Corinne; Brenier, Charlotte; Bonnet, Pierre-Antoine

    2014-02-15

    A GC/MS method was developed for the identification and quantification of 14 phthalates: 8 phthalates classified H360 (DBP, DEHP, BBP, DMEP, DnPP, DiPP, DPP and DiBP), 3 phthalates proposed to be forbidden in medical devices (DnOP, DiNP and DiDP) and 3 other phthalates none regulated (DMP, DCHP and DEP) which may interfere with hormone function. In order to identify and quantify other plasticizers that are commonly used in PVC medical devices such as DEHP substitute, 5 non-phthalate plasticizers (ATBC, DEHA, DEHT, TOTM, and DINCH) were included in this study. Analyses are carried out on a GC/MS system with electron impact ionization mode (EI). The separation of plasticizers is obtained on a cross-linked 5%-phenyl/95%-dimethylpolysiloxane capillary column 30m×0.25mm (i.d.)×0.25μm film thickness using a gradient temperature. Compounds quantification is performed by external calibration using an internal standard. Validation elements on standard solutions were determined using the ISO 12787 standard approach. Plasticizers are extracted from PVC medical devices using THF for dissolving the PVC part of the sample followed by precipitation of the PVC by addition of ethanol. The supernatant is injected into a GC/MS system after dilution in ethanol. Different validation elements, including extraction recoveries for all compounds or for DEHP a cross-validation of the extraction process using the European pharmacopoeia monograph 3.1.14 as reference method, are discussed. Results obtained on 61 medical devices in PVC and 12 raw materials used as plasticizers are given.

  13. Pilot study on the contamination of drinking water by organotin compounds from PVC materials.

    PubMed

    Sadiki, A I; Williams, D T; Carrier, R; Thomas, B

    1996-06-01

    Raw and treated water samples and tap water samples from four to six houses located on distribution lines where PVC pipe/tubing had been recently installed were collected in five Canadian municipalities for the analysis of organotin compounds. After derivatisation with sodium tetraethylborate the ethylated organotin compounds were extracted with hexane and analysed by gas chromatography-microwave induced plasma atomic emission spectrometry using a wavelength (326.234 nm) specific for tin. Organotin compounds, mainly methyltin and dimethyltin at concentrations ranging respectively from 0.5 to 257 ng Sn/L and from 0.5 to 6.5 ng Sn/L, were detected in samples from ten of the twenty-two houses. No organotin compounds were detected in raw water or treated water leaving the treatment plant, indicating that the organotin compounds were leaching into the water from some component of the distribution system.

  14. Thermal degradation products from PVC film in food-wrapping operations.

    PubMed

    Boettner, E A; Ball, G L

    1980-07-01

    Thermal degradation products of polyvinyl chloride (PVC) food-wrap films were studied under simulated supermarket conditons using a commercial wrapping machine with either a hot wire or a cool rod cutting device. A sampling hood was constructed around the wire/rod to confine and allow collection of thermal degradation products produced. Compounds analyzed and normal concentration ranges found included hydrogen chloride (1-10 micrograms per cut), plasticizer (1-50 micrograms per cut), benzene and toluene (each < 5-20 ng per cut), acrolein (25-150 ng per cut), and carbon monoxide (2-4 micrograms per cut) using the hot wire. Room air samples, collected during hot-wire cutting without the sampling hood, had < 0.25 ppm hydrogen chloride. Using the cool-rod cutting device hydrogen chloride, benzene, and toluene were not detected. Plasticizer was detected (25-86 micrograms per cut) using the cool rod.

  15. Migration of di-(2-ethylhexyl) phthalate from PVC child articles into saliva and saliva simulant.

    PubMed

    Steiner, I; Scharf, L; Fiala, F; Washüttl, J

    1998-10-01

    A simple migration test and a more complicated simulation of children's sucking and biting was used to establish migration of DEHP from PVC child-use articles into saliva and compared to a mimic test. The static migration test of a film containing approximately 30% DEHP with saliva simulant gave the lowest values of DEHP; simple shaking increased the amounts of DEHP from 25 +/- 8 to 499 +/- 153 micrograms/g film. The more complicated arrangements to simulate sucking and biting are not so suitable for standard applications. When comparing the in vitro migration tests with the mimic test the factors were 25 and 29 for the static tests (3 and 6 hours) and 1.4 for the shaking test.

  16. Study of structural, morphological and mechanical properties of PMMA, PVC and their blends

    NASA Astrophysics Data System (ADS)

    Kelkar, D. S.; Soman, Vijay V.

    2012-02-01

    PMMA, PVC and their five blends in different compositions were irradiated by γ -rays of 2 Mrad dose. A comparative study of structural, morphological and mechanical properties of irradiated and non-irradiated samples was carried out. The structural changes that have taken place due to irradiation are seen in the FTIR and X-ray diffraction (XRD) spectra. The ester group is mainly affected in PMMA and the blends. The XRD results have confirmed that the irradiated samples are more amorphous in nature than the non-irradiated ones. The DSC study reveals that some irradiated samples undergo cross-linking, whereas some of them undergo degradation. One of the irradiated blend compositions has become thermally more stable. The SEM study suggests that the irradiated samples have undergone curing. An improvement in the mechanical properties has been observed in some of the irradiated blend compositions.

  17. Crosslinking of rigid PVC by ionizing radiation to improve its thermal properties

    NASA Astrophysics Data System (ADS)

    García-Castañeda, C.; Benavides, R.; Martínez-Pardo, M. E.; Uribe, R. M.; Carrasco-Ábrego, H.; Martínez, G.

    2010-03-01

    Rigid PVC formulations containing two different stabilizer systems (tin and Ca/Zn) and TMPTMA as a crosslinking agent were treated with ionizing radiation (gamma and electron beam) at different doses and irradiation atmospheres. The objective was to increase thermal and mechanical properties of this material. Polyene formation was followed through the yellowing index (YI), the extent of crosslinking by gel percentage, thermal resistance by Vicat temperature and the mechanical properties by DMA. Both formulations became colored with irradiation, especially with gamma as a result of a longer treatment time; the gel formation and the Vicat temperature were also higher for gamma treated samples, suggesting that values were enhanced by oxidation. However, DMA elastic modulus traces were almost similar for both treatments. The main difference observed for Ca/Zn samples compared with traditional tin samples was the lower ability of the former system in protecting the material against processing conditions.

  18. Identification of young modulus profile in PVC foam core thickness using speckle inteferometry and inverse method

    NASA Astrophysics Data System (ADS)

    Ferreira, Carlos; Casari, Pascal; Bouzidi, Rabah; Jacquemin, Frédéric

    2006-09-01

    The aim of this paper is to investigate the mechanical properties of a PVC foam core and especially the Young modulus profile along a commercialised 50 mm beam thickness. The identification of the Young modulus gradient is realized through the uniaxial compression test of a 50 mm cube sample. The in-plane strain fields of one cube face under loading in both directions (longitudinal and transversal) are achieved using a diffuse light interferometric technique, the speckle interferometry. Next to that, a numerical model is built using finite elements code CAST3M. We choose a multilayer model in order to introduce spatial variation of the mechanical properties. The boundaries conditions are very close to those prescribed in the experimental tests. Finally, the present work shows that the non uniform profile of the Young modulus can be estimated by using a simple inverse method and the finite elements analysis to reproduce the experimental strain field.

  19. Binding of ligands containing carbonyl and phenol groups to iron(iii): new Fe6, Fe10 and Fe12 coordination clusters.

    PubMed

    Kitos, Alexandros A; Papatriantafyllopoulou, Constantina; Tasiopoulos, Anastasios J; Perlepes, Spyros P; Escuer, Albert; Nastopoulos, Vassilios

    2017-03-07

    The initial use of ligands 2'-hydroxyacetophenone (HL(1)), 2-hydroxybenzophenone (HL(2)) and 2,2'-dihydroxybenzophenone (H2L(3)) in iron(iii) chemistry is described. The syntheses and crystal structures are reported for five iron(iii) clusters: [Fe10O4(OMe)14(L(1))6(MeOH)2](NO3)2·3MeOH (1·3MeOH), [Fe12O4(OH)(OMe)17(L(1))8](ClO4)2·2H2O (2·2H2O), [Fe10O4(OMe)14Cl4(L(2))4(MeOH)2] (3), [Fe10O4(OMe)14(L(2))6(py)2](ClO4)2·MeOH (4·MeOH), where py = pyridine, and [Fe6O2(OEt)6(O2CMe)2(L(3))2(HL(3))2] (5). The molecular structures of the decanuclear clusters 1, 3 and 4 are organized around a {Fe10(μ4-O)4(μ3-OMe)2(μ-OMe)12}(8+) core consisting of ten {Fe3O4} face-sharing defective cubane units. The core of 2 consists of a {Fe12(μ4-O)4(μ3-OMe)4(μ-OH)(μ-OMe)13}(10+) unit composed of twelve {Fe3O4} face-sharing defective cubanes. The ligands (L(1))(-) and (L(2))(-) in 1-4 adopt the O,O'-bidentate chelating coordination mode and their roles are to terminate the further aggregation of the Fe(III)/O(2-)/RO(-) cores. Complex 5 contains the {Fe6(μ4-O)2(μ-OEt)6(μ-Ocarbonyl)2}(4+) core, where the μ-Ocarbonyl atoms are the bridging carbonyl oxygens of the two η(1):η(2):η(1):μ (L(3))(2-) ligands; the (HL(3))(-) groups behave as Ophenolate, Ocarbonyl-bidentate chelating ligands with the neutral hydroxyl group being unbound to the Fe(III) atoms. The core is composed of four {Fe3O4} face-sharing defective cubanes. The Fe(III) atoms in 1-5 are all six-coordinate with distorted octahedral geometries. The IR spectra of the complexes are discussed in terms of the known coordination modes of the ligands and the ionic character of nitrates and perchlorates. Variable-temperature magnetic susceptibility and variable-field magnetization measurements establish that 2, 3 and 5 have S = 3, 0 and 5 ground states, respectively. The susceptibility data for 5 were fitted using a 3-J model indicating the simultaneous presence of both antiferromagnetic and ferromagnetic Fe

  20. Rheology of PVC Plastisol: Formation of Immobilized Layer in Pseudoplastic Flow.

    PubMed

    Nakajima, N.; Harrell, E. R.

    2001-06-01

    Hoffman in the early 1970s examined mechanism of dilatancy and fracture of plastisol under high-shear conditions. The samples were monodispersed spherical particles of PVC. He discovered formation of immobilized layer in the pseudoplastic flow preceding dilatancy and subsequent destruction of the layer at the fracture. However, his analysis was focused primarily on the mechanism of the fracture, and the mechanism of pseudoplastic flow remains unexplored. The present work begins with analyses of Hoffman's data to show that pseudoplastic flow, i.e., the decrease of viscosity with the increase of shear rate, is a result of the development of the immobilized layer and creation of a mobile layer of low-viscosity fluid. Hoffman took the mobile layer to consist of pure plasticizer. The present work shows that the mobile layer contains PVC particles. The thickness of mobile layer decreases (and the thickness of immobilized layer increases) with the increase of shear rate. The particle concentration and hence viscosity of the mobile layer decrease with the increase of shear rate. Similar analyses of our dynamic viscosity-frequency relationship show that (1) the pseudoplastic behavior is a result of formation of immobilized layer, which grows thicker with the increasing frequency, and (2) the mobile layer contains dispersed particles, the concentration of which decreases with increasing frequency. (3) A presence of coarse particles results in a tighter packing of the immobilized layer and lower viscosity of the mobile layer for a given volume fraction of particles. This explains why the presence and the amount of the coarse particles are important parameters in plastisol formulation. The elastic modulus-frequency relationship is also interpreted with the development of the immobilized layer, giving strain amplification. Copyright 2001 Academic Press.

  1. Iron(III) complexes of tripodal tetradentate 4N ligands as functional models for catechol dioxygenases: the electronic vs. steric effect on extradiol cleavage.

    PubMed

    Balamurugan, Mani; Vadivelu, Prabha; Palaniandavar, Mallayan

    2014-10-21

    A few mononuclear iron(iii) complexes of the type [Fe(L)Cl2]Cl , where L is a tetradentate tripodal 4N ligand such as N,N-dimethyl-N',N'-bis(pyrid-2-ylmethyl)ethane-1,2-diamine (), N,N-diethyl-N',N'-bis(pyrid-2-ylmethyl)ethane-1,2-diamine (), N,N-dimethyl-N',N'-bis-(6-methylpyrid-2-ylmethyl)ethane-1,2-diamine (), N,N-dimethyl-N'-(pyrid-2-ylmethyl)-N'-(1-methyl-1H-imidazol-2-ylmethyl)ethane-1,2-diamine (), N,N-dimethyl-N',N'-bis(1-methyl-1H-imidazol-2-ylmethyl)ethane-1,2-diamine () and N,N-dimethyl-N',N'-bis(quinolin-2-ylmethyl)ethane-1,2-diamine (), have been isolated and characterized by CHN analysis, UV-Visible spectroscopy and electrochemical methods. The complex cation [Fe(H)Cl3](+) possesses a distorted octahedral geometry in which iron is coordinated by the monoprotonated 4N ligand in a tridentate fashion and the remaining three sites of the octahedron are occupied by chloride ions. The DFT optimized octahedral geometries of , and contain iron(iii) with a high-spin (S = 5/2) ground state. The catecholate adducts [Fe(L)(DBC)](+), where H2DBC is 3,5-di-tert-butylcatechol, of all the complexes have been generated in situ in acetonitrile solution and their spectral and redox properties and dioxygenase activities have been studied. The DFT optimized geometries of the catecholate adducts [Fe()(DBC)](+), [Fe()(DBC)](+) and [Fe()(DBC)](+) have also been generated to illustrate the ability of the complexes to cleave H2DBC in the presence of molecular oxygen to afford varying amounts of intra- (I) and extradiol (E) cleavage products. The extradiol to intradiol product selectivity (E/I, 0.1-2.0) depends upon the asymmetry in bidentate coordination of catecholate, as determined by the stereoelectronic properties of the ligand donor functionalities. While the higher E/I value obtained for [Fe()(DBC)](+) is on account of the steric hindrance of the quinolyl moiety to coordination the lower value observed for [Fe()(DBC)](+) and [Fe()(DBC)](+) is on account of the electron

  2. Investigation into the sorption of nitroglycerin and diazepam into PVC tubes and alternative tube materials during application.

    PubMed

    Treleano, Anna; Wolz, Gerd; Brandsch, Rainer; Welle, Frank

    2009-03-18

    Plastic bags and tubes are increasingly used for the storage and application of pharmaceutical formulations. The most common polymer material for drug application sets is plasticized poly(vinylchloride) (PVC). During application of pharmaceutical drug solution through PVC tubes, the polymer and the contact media interact which leads to leaching out of polymer additives or sorption of ingredients of the drug solution. Whereas the discussion of leaching of plasticizers is focussed on the toxicological properties of a drug packaging system, the sorption of drug formulation compounds has an influence on the dosage of the active pharmaceutical ingredient resulting in a reduced drug delivery to the patient. Therefore sorption has an influence on the effectiveness and success of the therapy. Within the study, the concentration profiles of nitroglycerin and diazepam solutions were determined after pumping the solutions through infusion administration sets. The study includes plasticized PVC tubes with different plasticizers (DEHP, DEHA, DEHT, TEHTM, DINCH, poly adipate), PVC (DEHP) tubes with different shore hardness as well as alternative polymer materials like EVA, TPE, PUR, silicone, LDPE and PP. From the experimental concentration curves it could be shown, that in the first minutes of the application of the drug solution the sorption of the active compound is at its maximum, resulting in the lowest concentration in the applied pharmaceutical solution. For a PVC tube with DEHP as plasticizer and a shore hardness of 80 only about 57% of the initial nitroglycerin concentration in the solution is applied to the patient in the first minutes of the application. For PVC tube (DEHP, shore 80) the experimental data were simulated using mathematical diffusion models. The concentration profiles during application could be well simulated using the partition coefficient K=50 (nitroglycerin) and K=300 (diazepam), respectively. However, the experimental results indicate, that the

  3. Optical sensor of anionic surfactants using solid-phase extraction with a lactone-form rhodamine B membrane.

    PubMed

    Masadome, Takashi; Akatsu, Motoo

    2008-06-01

    An optical sensor for the detection of anionic surfactants was developed. The optical sensing membrane is a 2-nitrophenyloctyl ether-plasticized poly(vinyl chloride) membrane incorporating a lactone-form Rhodamine B (L-RB). The response of the optical membrane to anionic surfactants was a result of the ion-pair coextraction of an anionic surfactant and a proton into the PVC membrane. The L-RB forms an ion associate with the extracted anionic surfactant; simultaneously, the formed L-RB ion associate is accompanied by a spectral change. Namely, the extracted anionic surfactant changes the color of the membrane from light pink to dark pink (absorption maximum; 558 nm). The optical membrane responds to anionic surfactants, such as dodecylbenzenesulfonate, dodecylsulfate and di-2-ethylhexyl sulfosuccinate in the concentration range from 1 to 50 microM.

  4. Crystalline Membranes

    NASA Technical Reports Server (NTRS)

    Tsapatsis, Michael (Inventor); Lai, Zhiping (Inventor)

    2008-01-01

    In certain aspects, the invention features methods for forming crystalline membranes (e.g., a membrane of a framework material, such as a zeolite) by inducing secondary growth in a layer of oriented seed crystals. The rate of growth of the seed crystals in the plane of the substrate is controlled to be comparable to the rate of growth out of the plane. As a result, a crystalline membrane can form a substantially continuous layer including grains of uniform crystallographic orientation that extend through the depth of the layer.

  5. Biological membranes

    PubMed Central

    Watson, Helen

    2015-01-01

    Biological membranes allow life as we know it to exist. They form cells and enable separation between the inside and outside of an organism, controlling by means of their selective permeability which substances enter and leave. By allowing gradients of ions to be created across them, membranes also enable living organisms to generate energy. In addition, they control the flow of messages between cells by sending, receiving and processing information in the form of chemical and electrical signals. This essay summarizes the structure and function of membranes and the proteins within them, and describes their role in trafficking and transport, and their involvement in health and disease. Techniques for studying membranes are also discussed. PMID:26504250

  6. Characterization of emissions of dioxins and furans from ethylene dichloride (EDC), vinyl chloride (VCM) and polyvinylchloride (PVC) facilities in the United States.

    SciTech Connect

    Carroll, W.F. Jr.; Borrelli, F.E.; Garrity, P.J.; Jacobs, R.A.; Lewis, J.W.; McCreedy, R.L.; Weston, A.F.; Ledvina, J.C.

    1997-12-31

    Members of The Vinyl Inst., under the auspices of its Dioxin Characterization Program have analyzed for potential dioxin/furan (PCDD/F) concentrations in polyvinylchloride (PVC) resins, treated wastewater effluent, ethylene dichloride (EDC) product and wastewater sludge at EDC, vinyl chloride (VCM) and PVC facilities. No 2,3,7,8-TCDD was detected in any sample analyzed under the program to date. Results from wastewater sludge analysis are pending. Trace concentrations (low pg/g) of PCDD/F were detected in only a few samples of PVC resins and ethylene dichloride (EDC) product. Treated wastewater contained low ppq concentrations of PCDD/F. All concentrations are expressed as Toxicity Equivalents (TEQ). Extrapolation of these data shows that the contribution of EDC/VCM/PVC manufacturing via these media constitutes less than 1 percent of the US annual dioxin emission to the environment.

  7. Iron(III) [bond] Salen complexes as enzyme models: mechanistic study of oxo(salen)iron complexes oxygenation of organic sulfides.

    PubMed

    Sivasubramanian, Veluchamy Kamaraj; Ganesan, Muniyandi; Rajagopal, Seenivasan; Ramaraj, Ramasamy

    2002-03-08

    The oxidation of a series of para-substituted phenyl methyl sulfides was carried out with several oxo(salen)iron (salen = N,N'-bis(salicylidine)ethylenediaminato) complexes in acetonitrile. The oxo complex [O=Fe(IV)(salen)](*+), generated from an iron(III) [bond] salen complex and iodosylbenzene, effectively oxidizes the organic sulfides to the corresponding sulfoxides. The formation of [O [double bond] Fe(IV)(salen)](*+) as the active oxidant is supported by resonance Raman studies. The kinetic data indicate that the reaction is first-order in the oxidant and fractional-order with respect to sulfide. The observed saturation kinetics of the reaction and spectral data indicate that the substrate binds to the oxidant before the rate-controlling step. The rate constant (k) values for the product formation step determined using Michaelis-Menten kinetics correlate well with Hammett sigma constants, giving reaction constant (rho) values in the range of -0.65 to -1.54 for different oxo(salen)iron complexes. The log k values observed in the oxidation of each aryl methyl sulfide by substituted oxo(salen)iron complexes also correlate with Hammett sigma constants, giving positive rho values. The substituent effect, UV-vis absorption, and EPR spectral studies indicate oxygen atom transfer from the oxidant to the substrate in the rate-determining step.

  8. Biosorption of copper(II), lead(II), iron(III) and cobalt(II) on Bacillus sphaericus-loaded Diaion SP-850 resin.

    PubMed

    Tuzen, Mustafa; Uluozlu, Ozgur Dogan; Usta, Canan; Soylak, Mustafa

    2007-01-09

    The biosorption of copper(II), lead(II), iron(III) and cobalt(II) on Bacillus sphaericus-loaded Diaion SP-850 resin for preconcentration-separation of them have been investigated. The sorbed analytes on biosorbent were eluted by using 1 mol L(-1) HCl and analytes were determined by flame atomic absorption spectrometry. The influences of analytical parameters including amounts of pH, B. sphaericus, sample volume etc. on the quantitative recoveries of analytes were investigated. The effects of alkaline, earth alkaline ions and some metal ions on the retentions of the analytes on the biosorbent were also examined. Separation and preconcentration of Cu, Pb, Fe and Co ions from real samples was achieved quantitatively. The detection limits by 3 sigma for analyte ions were in the range of 0.20-0.75 microg L(-1) for aqueous samples and in the range of 2.5-9.4 ng g(-1) for solid samples. The validation of the procedure was performed by the analysis of the certified standard reference materials (NRCC-SLRS 4 Riverine Water, SRM 2711 Montana soil and GBW 07605 Tea). The presented method was applied to the determination of analyte ions in green tea, black tea, cultivated mushroom, boiled wheat, rice and soil samples with successfully results.

  9. Manganese-incorporated iron(III) oxide-graphene magnetic nanocomposite: synthesis, characterization, and application for the arsenic(III)-sorption from aqueous solution

    NASA Astrophysics Data System (ADS)

    Nandi, Debabrata; Gupta, Kaushik; Ghosh, Arup Kumar; De, Amitabha; Banerjee, Sangam; Ghosh, Uday Chand

    2012-12-01

    High specific surface area of graphene (GR) has gained special scientific attention in developing magnetic GR nanocomposite aiming to apply for the remediation of diverse environmental problems like point-of-use water purification and simultaneous separation of contaminants applying low external magnetic field (<1.0 T) from ground water. Fabrication of magnetic manganese-incorporated iron(III) oxide (Mn x 2+Fe2- x 3+O4 2-) (IMBO)-GR nanocomposite is reported by exfoliating the GR layers. Latest microscopic, spectroscopic, powder X-ray diffraction, BET surface area, and superconducting quantum interference device characterizations showed that the material is a magnetic nanocomposite with high specific surface area (280 m2 g-1) and pore volume (0.3362 cm3 g-1). Use of this composite for the immobilization of carcinogenic As(III) from water at 300 K and pH 7.0 showed that the nanocomposite has higher binding efficiency with As(III) than the IMBO owing to its high specific surface area. The composite showed almost complete (>99.9 %) As(III) removal (≤10 μg L-1) from water. External magnetic field of 0.3 T efficiently separated the water dispersed composite (0.01 g/10 mL) at room temperature (300 K). Thus, this composite is a promising material which can be used effectively as a potent As(III) immobilizer from the contaminated groundwater (>10 μg L-1) to improve drinking water quality.

  10. Light-Induced Bistability in Iron(III) Spin-Transition Compounds of 5 X-Salicylaldehyde Thiosemicarbazone (X=H, Cl, Br).

    PubMed

    Yemeli, Eddy W T; Blake, Graeme R; Douvalis, Alexios P; Bakas, Thomas; Alberda van Ekenstein, Gert O R; van Koningsbruggen, Petra J

    2010-10-19

    The iron(III) spin-crossover compounds [Fe(Hthsa)(thsa)]⋅H2 O (1), [Fe(Hth5Clsa)(th5Clsa)2 ]⋅H2 O (2), and [Fe(Hth5Brsa)(th5Brsa)2 ]⋅H2 O (3) (H2 thsa=salicylaldehyde thiosemicarbazone, H2 th5Clsa=5-chlorosalicylaldehyde thiosemicarbazone, and H2 th5Brsa=5-bromosalicylaldehyde thiosemicarbazone) have been synthesized and their spin-transition properties investigated by magnetic susceptibility, Mössbauer spectroscopy, and differential scanning calorimetry measurements. The three compounds exhibit an abrupt spin transition with a thermal hysteresis effect. The more polarizable the substituent on the salicylaldehyde moiety, the more complete is the transition at room temperature with an increased degree of cooperativity. The molecular structures of 1 and 2 in the high-spin state are revealed. The occurrence of the light-induced excited-spin-state trapping phenomenon appears to be dependent on the substituent incorporated into the 5-position of the salicylaldehyde subunit. Whereas the compounds with an electron-withdrawing group (-Br or -Cl) exhibit light-induced trapped excited high-spin states with great longevity of metastability, the halogen-free compound does not, even though strong intermolecular interactions (such as hydrogen-bonding networks and π stacking) operate in the system. For compound 2, the surface level of photoconversion is less than 35 %. In contrast, compound 3 displays full photoexcitation.

  11. Effect of iron(III) sulphate on radiation-induced reduction of methyl viologen incorporated in poly(vinyl alcohol) film

    NASA Astrophysics Data System (ADS)

    Ohtani, Bunsho; Ye, Mu; Nishimoto, Sei-Ichi; Kagiya, Tsutomu

    Addition of iron(III) sulfate (Fe 2(SO 4) 3) to the methyl viologen (MV 2+)-poly(vinyl alcohol) (PVA) film dosimeter led to the induction dose ( Di) before appearance of blue-colored cation radical (MV +.) and reduction of G-value of MV +.. As a result, the measurable range for ionizing radiation (200 kV electron beam) was expanded to the higher dose >400 kGy, which was >25 times larger than that of base MV 2+-PVA film (<14 kGy). In the MV 2+-Fe 2(SO 4) 3-PVA film, iron(II) ion (Fe 2+) was also accumulated without any induction dose. The Fe 2+ still increased after Di, with the G-value relatively smaller than that before Di. Increase in pH ((pH) i) of the source aqueous PVA solution, subjected to casting into films, led to the decrease in Di and increase in G-value of MV +. ( G(MV +.)). The ratio of initial concentration of Fe 3+ (( CFe) i) to Di was apparently independent of ( CFe) i at given (pH) i. These results suggest the mechanism that radiation-induced electrons in the PVA matrix reduce both MV 2+ and Fe 3+, and the resulting MV +. successively reacts with neighboring Fe 3+ to regenerate MV 2+ in the initial stage of irradiation (within Di). At the dose of Di, such neighboring Fe 3+ is consumed entirely and substantial formation of MV +. can be observed.

  12. Selective sensing of submicromolar iron(III) with 3,3‧,5,5‧-tetramethylbenzidine as a chromogenic probe

    NASA Astrophysics Data System (ADS)

    Zhang, Lufeng; Du, Jianxiu

    2016-04-01

    The development of highly selective and sensitive method for iron(III) detection is of great importance both from human health as well as environmental point of view. We herein reported a simple, selective and sensitive colorimetric method for the detection of Fe(III) at submicromolar level with 3,3,‧5,5‧-tetramethylbenzidine (TMB) as a chromogenic probe. It was observed that Fe(III) could directly oxidize TMB to form a blue solution without adding any extra oxidants. The reaction has a stoichiometric ratio of 1:1 (Fe(III)/TMB) as determined by a molar ratio method. The resultant color change can be perceived by the naked eye or monitored the absorbance change at 652 nm. The method allowed the measurement of Fe(III) in the range 1.0 × 10- 7-1.5 × 10- 4 mol L- 1 with a detection limit of 5.5 × 10- 8 mol L- 1. The relative standard deviation was 0.9% for eleven replicate measurements of 2.5 × 10- 5 mol L- 1 Fe(III) solution. The chemistry showed high selectivity for Fe(III) in contrast to other common cation ions. The practically of the method was evaluated by the determination of Fe in milk samples; good consistency was obtained between the results of this method and atomic absorption spectrophotometry as indicated by statistical analysis.

  13. Synthesis of lithium iron phosphate/carbon microspheres by using polyacrylic acid coated iron phosphate nanoparticles derived from iron(III) acrylate.

    PubMed

    Xu, Dongwei; He, Yan-Bing; Chu, Xiaodong; Ding, Zhaojun; Li, Baohua; He, Jianfu; Du, Hongda; Qin, Xianying; Kang, Feiyu

    2015-03-01

    Lithium iron phosphate/carbon (LiFePO4 /C) microspheres with high rate and cycling performance are synthesized from iron phosphate/polyacrylic acid (FePO4 /PAA) nanoparticles. Iron(III) acrylate is used as a precursor for both the iron and carbon sources. FePO4 nanoparticles are first produced by a coprecipitation reaction. The byproduct, acrylic acid ions, is polymerized in situ to form a uniform PAA layer on the surface of the FePO4 nanoparticles. The as-prepared LiFePO4 /C microspheres are composed of primary nanoparticles with sizes of 40-50 nm. The nanoparticles are fully coated with a thin, uniform carbon layer derived from the decomposition of the PAA layer. The uniform carbon-coating layer cooperates with interstitial and boundary carbon derived from sucrose successfully to construct an excellent interconnecting conductive network in the microspheres. As a result of the unique structure, the as-prepared LiFePO4 /C microspheres display both high electronic and ionic conductivities, which contribute to their high rate performance (162.9 mAh g(-1) at 0.1C and 126.1 mAh g(-1) at 5C) and excellent cycling stability (97.1% of capacity retention after 500 cycles at 5C/5C).

  14. Studies on solvent extraction of iron(III) as a step for conversion of a waste effluent to a value added product.

    PubMed

    Agrawal, Archana; Kumari, S; Sahu, K K

    2011-12-01

    Solvent extraction of iron(III) from actual sulphate waste pickle liquor was investigated using trialkylphosphine oxide diluted with kerosene. The waste pickle liquor was procured from a local company which deals with the manufacturing of pipes and tubes made of iron and steel. Various parameters were studied to optimise a suitable condition for the maximum extraction of iron. The composition of the aqueous feed used in the experiment was 60.88 g/L Fe(III), 53 g/L acid with traces of Cu, Ni and Co. An ambient extraction at 30 °C yielded acceptable kinetics and loading efficiency for 40% trialkylphosphine oxide with a saturated loading capacity of 51.85 g/L in four contacts at O/A ratio of 1/1 in a multiple contact mode. Iron from the loaded organic was stripped using various strippants such as distilled water, H(2)SO(4) and oxalic acid. Since only 32% of loaded Fe could be stripped with 2 M H(2)SO(4) in five contacts, further stripping was done with 5% oxalic acid which showed a very promising result. It was found that almost 100% of Fe(III) could be stripped out with 5% oxalic acid at O/A of 1/1 in five contacts.

  15. Covalent organic/inorganic hybrid proton-conductive membrane with semi-interpenetrating polymer network: Preparation and characterizations

    NASA Astrophysics Data System (ADS)

    Fu, Rong-Qiang; Woo, Jung-Je; Seo, Seok-Jun; Lee, Jae-Suk; Moon, Seung-Hyeon

    2008-05-01

    A series of new covalent organic/inorganic hybrid proton-conductive membranes, each with a semi-interpenetrating polymer network (semi-IPN), for direct methanol fuel cell (DMFC) applications is prepared through the following sequence: (i) copolymerization of impregnated styrene (St), p-vinylbenzyl chloride (VBC) and divinylbenzene (DVB) within a supporting polyvinyl chloride (PVC) film; (ii) reaction of the chloromethyl group with 3-(methylamine)propyl-trimethoxysilane (MAPTMS); (ii) a sol-gel process under acidic conditions; (iv) a sulfonation reaction. The developed membranes are characterized in terms of Fourier transform infrared/attenuated total reflectance (FTIR/ATR), scanning electron microscopy/energy-dispersive X-ray analysis (SEM/EDXA), elemental analysis (EA) and thermogravimetric analysis (TGA), which confirm the formation of the target membranes. The developed copolymer chains are interpenetrating with the PVC matrix to form the semi-IPN structure, and the inorganic silica is covalently bound to the copolymers. These features provide the membranes with high mechanical strength. The effect of silica content is investigated. As the silica content increases, proton conductivity and water content decrease, whereas oxidative stability is improved. In particular, methanol permeability and methanol uptake are reduced largely by the silica. The ratio of proton conductivity to methanol permeability for the hybrid membranes is higher than that of Nafion 117. All these properties make the hybrid membranes a potential candidate for DMFC applications.

  16. Sustainable and Selective Separation of PVC and ABS from a WEEE Plastic Mixture Using Microwave and/or Mild-Heat Treatment with Froth Flotation.

    PubMed

    Thanh Truc, Nguyen Thi; Lee, Byeong-Kyu

    2016-10-04

    This study reports simple, selective, and sustainable separation of chlorinated plastic (polyvinyl chloride, PVC) and acrylonitrile butadiene styrene (ABS) containing brominated flame retardants (BFRs) from mixed waste electrical and electronic equipment (WEEE) plastics using microwave and/or mild-heat treatment. Microwave treatment after plastic coating with powdered activated carbon (PAC) selectively increased the hydrophilicity of the PVC surface, which facilitated PVC separation (100% recovery and purity) from the WEEE plastic mixture under the optimum flotation conditions. A further mild-heat treatment for 100 s facilitated selective separation with the highest recovery and purity (100%) of PAC-coated ABS containing BFRs from the remaining plastic mixture due to selective formation of a twisted structure with a lower density than water and the untreated ABS. Mild-heat treatment only of PAC-coated WEEE plastic mixture resulted in successful recovery of (100%) the ABS and PVC. However, the recovered PVC had slightly reduced purity (96.8%) as compared to that obtained using the combined heat and microwave treatments. The combination of both treatments with flotation facilitated selective and sustainable separation of PVC and ABS from WEEE plastics to improve their recycling quality.

  17. A study of the behavior of bi-oriented PVC exposed to ionizing radiation and its possible use in nuclear applications

    NASA Astrophysics Data System (ADS)

    Campi, F.; Casagrande, M.; Franzoni, G.; Minelli, C.; Porta, A.; Ramella, G.

    2014-06-01

    The paper discusses whether bi-oriented PVC, obtained by modifying the structures of polymers chains to enhance the mechanical properties of unplasticized PVC, could successfully replace metallic materials in industrial applications where radioactive fluids are processed and an intense field of ionizing radiation is present. Tests have been carried out in order to study the behavior of a commercial bi-oriented PVC when exposed to ionizing radiations. A numerical simulation allows comparing the effects of radiation expected on the pipe in nuclear industry applications with those resulting from the irradiation tests. Contamination and decontamination tests of bi-oriented PVC in contact with a radioactive solution have been performed too. Results show that the bi-oriented PVC can withstand high β and γ radiation doses (up to 100 kGy) without showing significant degradation in mechanical properties; bi-orientation of polymers chains in the bulk of material is not affected even to much higher doses (250 kGy); the decontamination of the material is satisfactory. The results suggest that tested commercial bi-oriented PVC could be considered in nuclear industry applications.

  18. Compositional GC-FID analysis of the additives to PVC, focusing on the gaskets of lids for glass jars.

    PubMed

    Biedermann-Brem, Sandra; Biedermann, Maurus; Fiselier, Katell; Grob, Koni

    2005-12-01

    A gas chromatographic (FID) method is described which aims at the quantitative compositional analysis of the additives in plasticized PVC, particularly the plastisols used as gaskets for lids of glass jars. An extract of the PVC is analysed directly as well as after transesterification to ethyl esters. Transesterification enables the analysis of epoxidized soya bean and linseed oil (ESBO and ELO) as well as polyadipates. For most other additives, the shifts in the chromatogram resulting from transesterification is used to confirm the identifications made by direct analysis. In the gaskets of 69 lids from the European market used for packaging oily foods, a broad variety of plastisol compositions was found, many or possibly all of which do not comply with legal requirements. In 62% of these lids, ESBO was the principal plasticizer, whereas in 25% a phthalate had been used.

  19. Complete band gaps in a polyvinyl chloride (PVC) phononic plate with cross-like holes: numerical design and experimental verification.

    PubMed

    Miniaci, Marco; Marzani, Alessandro; Testoni, Nicola; De Marchi, Luca

    2015-02-01

    In this work the existence of band gaps in a phononic polyvinyl chloride (PVC) plate with a square lattice of cross-like holes is numerically and experimentally investigated. First, a parametric analysis is carried out to find plate thickness and cross-like holes dimensions capable to nucleate complete band gaps. In this analysis the band structures of the unitary cell in the first Brillouin zone are computed by exploiting the Bloch-Floquet theorem. Next, time transient finite element analyses are performed to highlight the shielding effect of a finite dimension phononic region, formed by unitary cells arranged into four concentric square rings, on the propagation of guided waves. Finally, ultrasonic experimental tests in pitch-catch configuration across the phononic region, machined on a PVC plate, are executed and analyzed. Very good agreement between numerical and experimental results are found confirming the existence of the predicted band gaps.

  20. Development of an improved membrane for a vapor diffusion water recovery process. [onboard manned spacecraft

    NASA Technical Reports Server (NTRS)

    Rich, T. R.; Mix, T. W.

    1974-01-01

    Recovery of potable water from urine on manned space missions of extended duration was the objective of work aimed at the improvement of membrane performance for the vapor diffusion process (VDR). Kynar, Teflon, PVC, and polysulfone candidate membranes were evaluated from chemical, thermal, mechanical, and fabricating standpoints to determine their suitability for operation in the VDR pervaporation module. Pervaporation rates and other performance characteristics were determined in a breadboard pervaporator test rig. Kynar and Teflon membranes were demonstrated to be chemically stable at pervaporation temperatures in urine pretreated with chromic acid bactericide. The separation of the pervaporator and condenser modules, the use of a recirculating sweep gas to conduct pervaporate to the condenser, and the selection of a hollow fiber membrane configuration for pervaporator module design is recommended as a result of the investigation.

  1. A novel polymer inclusion membrane applied in chromium (VI) separation from aqueous solutions.

    PubMed

    Gherasim, Cristina-Veronica; Bourceanu, Gelu; Olariu, Romeo-Iulian; Arsene, Cecilia

    2011-12-15

    In the present work, we analyze the transport properties of a novel polymer inclusion membrane (PIM) containing a poly-vinyl chloride (PVC) polymer matrix and the organic anion exchanger Aliquat 336 as a specific carrier, without addition of plasticizers. The study was specifically focused on the transport properties of Cr(VI) in conditions simulating industrial wastewaters. We analyzed the impact of several parameters on the Cr(VI) transport process such as: the carrier content of the PIM, the pH, and the phases' composition. We concluded that efficient transport processes occur through a PIM containing 40% Aliquat 336/60% PVC (w/w). The process is very fast and efficient for solutions of initial Cr(VI) concentration smaller than 10(-3)mol/L, in which nearly all of Cr(VI) is removed within 3h. The performed experiments prove that Cr(VI) transport through the membrane is a facilitated counter-transport process. The obtained results sustain that this novel non-plasticized membrane possesses enhanced transport properties towards other liquid membranes and plasticized PIMs previously reported as used for Cr(VI) transport. Additionally, it possesses an excellent reliability and a high selectivity for Cr(VI) from mixtures with other metal ions and anions existing in the real industrial effluents. The PIM characterization highlights the plasticizing role of the carrier Aliquat 336.

  2. Current-transport mechanism in Au/V-doped PVC+TCNQ/p-Si structures

    NASA Astrophysics Data System (ADS)

    Tecimer, H.; Vural, Ö.; Kaya, A.; Altındal, Ş.

    2015-03-01

    The forward and reverse bias current-voltage (I-V) characteristics of Au/V-doped polyvinyl chloride+Tetracyanoquino dimethane/porous silicon (PVC+TCNQ/p-Si) structures have been investigated in the temperature range of 160-340 K. The zero bias or apparent barrier height (BH) (Φap = ΦBo) and ideality factor (nap = n) were found strongly temperature dependent and the value of nap decreases, while the Φap increases with the increasing temperature. Also, the Φap versus T plot shows almost a straight line which has positive temperature coefficient and it is not in agreement with the negative temperature coefficient of ideal diode or forbidden bandgap of Si (αSi = -4.73×10-4eV/K). The high value of n cannot be explained only with respect to interfacial insulator layer and interface traps. In order to explain such behavior of Φap and nap with temperature, Φap Versus q/2kT plot was drawn and the mean value of (ΦBo) and standard deviation (σs) values found from the slope and intercept of this plot as 1.176 eV and 0.152 V, respectively. Thus, the modified (ln(Io/T2)-(qσs)2/2(kT)2 versus (q/kT) plot gives the ΦBo and effective Richardson constant A* as 1.115 eV and 31.94 Aṡ(cmṡK)-2, respectively. This value of A*( = 31.94 Aṡ(cmṡK)-2) is very close to the theoretical value of 32 Aṡ(cmṡK)-2 for p-Si. Therefore, the forward bias I-V-T characteristics confirmed that the current-transport mechanism (CTM) in Au/V-doped PVC+TCNQ/p-Si structures can be successfully explained in terms of the thermionic emission (TE) mechanism with a Gaussian distribution (GD) of BHs at around mean BH.

  3. Development of new generation of copolymers via reactive extrusion in a twin screw extruder and application in various PVC blends

    NASA Astrophysics Data System (ADS)

    Kim, In

    Polymerization in twin screw extruders has largely involved homopolymers. Here we generalize this and polymerize a range of copolymers and terpolymers including epsilon-caprolactam(CA), o-lauryl lactam(LA), epsilon-caprolactone(CL), and gamma-butyrolactone(GBL) in a modular intermeshing co-rotating twin screw extruder. We considered different types of copolymer structures (di-block, tri-block, and random-block) and different backbones of copolymer(lactams-lactones) as well as the variables of temperature profile, screw speed, monomer feed rate, the ratio of monomer to initiator, and feeding order of co-monomers on reactive extrusion of polyamides-polylactones based (co)polymers. Specially designed block copolymers have played a role as compatibilizing agents in the system of immiscible polymer blends. We apply the di-block copolymer(P(LA-b-CL)) and random block copolymer (P(LA/CA-b-CL)) produced by reactive extrusion as a compatibilizing agent in immiscible polymer blend systems: (i) poly(vinyl chloride) (PVC)/polyamide 12 (PA12), (ii) PVC/polypropylene(PP), and (iii) PVC/Ethylene-propylene-non-conjugated diene elastomer(EPDM).

  4. PVC cling film in contact with cheese: health aspects related to global migration and specific migration of DEHA.

    PubMed

    Petersen, J H; Naamansen, E T; Nielsen, P A

    1995-01-01

    Following exposure to the food simulant olive oil for 10 days at 5, 20 or 40 degrees C a global migration ranging from 20 to 30 mg/dm2 was detected from a common 'low migration' PVC film plasticized with a mixture of di-(ethylhexyl)adipate (DEHA) and a polymeric plasticizer. In a laboratory experiment samples of cheese of the types most commonly consumed in Denmark were wrapped in this 'low migration' PVC film using a procedure simulating the actual pattern of use in retail shops. After a storage time of 2 h at 5 degrees C the level of DEHA was 45 mg/kg of cheese, which after 10 days increased to 150 mg DEHA per kg of cheese, corresponding to an estimated specific migration of 12 mg DEHA/dm2 of cheese surface. Based on statistics on dietary habits it is concluded that the retail packaging of small portions of cheese even in a 'low migration' PVC cling film may lead to consumer intakes of DEHA close to or above the tolerable daily intake of 0.3 mg/kg body weight as defined by the EEC Scientific Committee for Food. Furthermore, it is stressed that measurements of global migration followed by uncritical use of reduction factors may result in erroneous evaluation of the suitability of DEHA-plasticized cling film for the packaging of fatty foods.

  5. Effects of TiO2 addition on ionic conductivity of PVC/PEMA blend based composite polymer electrolyte

    NASA Astrophysics Data System (ADS)

    Subban, R. H. Y.; Sukri, Nursyazwani

    2015-08-01

    PVC/PEMA blend based polymer electrolytes with lithium bistrifluoromethane sulfonimide (LiN(CF3SO2)2) and PVC/PEMA/(LiN(CF3SO2)2-TiO2 films were prepared by solution cast technique. The sample containing 35 wt. % LiN(CF3SO2)2 exhibited the highest conductivity of 1.75 × 10-5 Scm-1. The conductivity of the sample increased to 2.12 × 10-5 Scm-1 and 4.61 × 10-5 Scm-1 when 4 wt. % and 10 wt. % of titanium dioxide (TiO2) was added to the sample at 65 wt. % PVC/PEMA-35 wt. % LiN(CF3SO2)2 composition respectively. The low increase in conductivity is attributed to two competing factors: increase in crystallinity as accounted by X-Ray diffraction (XRD) and decrease in glass transition temperature as accounted by differential scanning calorimetry (DSC).

  6. Preparation and testing of a solid secondary plasticizer for PVC produced by chemical degradation of post-consumer PET.

    PubMed

    Amaro, Lucía Pérez; Coiai, Serena; Ciardelli, Francesco; Passaglia, Elisa

    2015-12-01

    Post-consumer poly(ethylene therephthalate) (PET) obtained from milled water bottles was chemically degraded by glycolysis, using suitable amounts of diethylene glycol (DEG) and Ca/Zn stearate as catalyst system. The process was carried out by employing a melt mixer as the chemical reactor, which is the facility generally used for plastic compounding. The degraded PET products were first characterized from structural and thermal point of view by Fourier transform infrared spectroscopy (FTIR), Proton nuclear magnetic resonance ((1)H NMR), Size exclusion chromatography (SEC) Differential scanning calorimetry (DSC) and Thermogravimetric analysis (TGA), and thereafter used alone or together with di(2-ethylhexyl) phthalate (DEHP) in poly(vinyl chloride) PVC formulations. The plasticization was, in fact, accomplished by using a binary system consisting of DEHP as primary plasticizer and a degraded PET product as secondary plasticizer (SP). The obtained materials were characterized through the main methods used to assess flexible PVC compounds: hardness in Shore A scale, thermal properties and quantitative migration of the plasticizer. The solid secondary plasticizer obtained from post-consumer PET improves both the processing characteristics and the thermal stability of the final flexible PVC compounds while maintaining their hardness within the top values of the Shore A scale. In addition, a considerable reduction of the plasticizers migration (23%) was obtained by optimizing the formulation.

  7. Effects of TiO{sub 2} addition on ionic conductivity of PVC/PEMA blend based composite polymer electrolyte

    SciTech Connect

    Subban, R. H. Y.; Sukri, Nursyazwani

    2015-08-28

    PVC/PEMA blend based polymer electrolytes with lithium bistrifluoromethane sulfonimide (LiN(CF{sub 3}SO{sub 2}){sub 2}) and PVC/PEMA/(LiN(CF{sub 3}SO{sub 2}){sub 2}-TiO{sub 2} films were prepared by solution cast technique. The sample containing 35 wt. % LiN(CF{sub 3}SO{sub 2}){sub 2} exhibited the highest conductivity of 1.75 × 10{sup −5} Scm{sup −1}. The conductivity of the sample increased to 2.12 × 10{sup −5} Scm{sup −1} and 4.61 × 10{sup −5} Scm{sup −1} when 4 wt. % and 10 wt. % of titanium dioxide (TiO{sub 2}) was added to the sample at 65 wt. % PVC/PEMA-35 wt. % LiN(CF{sub 3}SO{sub 2}){sub 2} composition respectively. The low increase in conductivity is attributed to two competing factors: increase in crystallinity as accounted by X-Ray diffraction (XRD) and decrease in glass transition temperature as accounted by differential scanning calorimetry (DSC)

  8. Study on plasma pre-functionalized PVC film grafted with TiO2/PVP to improve blood compatible and antibacterial properties

    NASA Astrophysics Data System (ADS)

    Suganya, Arjunan; Shanmugavelayutham, Gurusamy; Serra Rodríguez, Carmen

    2017-04-01

    Research into the design of new biopolymers/polymer functionalized with nanoparticles is of tremendous interest to the medical sector, particularly with regard to blood-contacting devices. In this present study, a steady blood compatible and active antibacterial coating was fabricated by the grafting of titanium dioxide (TiO2)/polyvinylpyyrolidone (PVP) onto a polyvinyl chloride (PVC) film surface via the direct-current glow discharge plasma method. To enhance the chemical interaction between TiO2/PVP and PVC, the surfaces of the PVC films were functionalized by different plasmas (air, argon, and oxygen) before coating. In this study, the plasma parameters were varied, such as treatment time of about 5–20 min for a constant power of 100 W, potential 300 V, and a constant gas pressure of 2 Pa for air, argon, and oxygen gas environment. Then, the different plasma treatments on the PVC films, TiO2/PVP were grafted using a simple dip-coating method. In addition, the TiO2/PVP-grafted PVC films were characterized by contact angle, attenuated total reflectance Fourier transform infrared spectroscopy, field-emission scanning electron microscope, and x-ray photo electron spectroscopy. Importantly, TiO2/PVP is grafted onto the PVC surface due to the plasma-based retained functionality and demonstrates adhesive efficiency, which was observed by XPS. The bio-stability of the TiO2/PVP-modified PVC film was evaluated by in vitro platelet activation analysis and protein adsorption analysis. Then, the antibacterial properties were evaluated by the agar diffusion method against Escherichia coli. The result reveals that the grafting of TiO2/PVP was slightly higher for the 15 min oxygen plasma-functionalized PVC, which significantly decreases the platelet adhesion and protein adsorption. Moreover, the antibacterial properties of the 15 min oxygen plasma-functionalized PVC with TiO2/PVP-grafted film is also greatly improved compared with an air- and argon

  9. Metamaterial membranes

    NASA Astrophysics Data System (ADS)

    Restrepo-Flórez, Juan Manuel; Maldovan, Martin

    2017-01-01

    We introduce a new class of metamaterial device to achieve separation of compounds by using coordinate transformations and metamaterial theory. By rationally designing the spatial anisotropy for mass diffusion, we simultaneously concentrate different compounds in different spatial locations, leading to separation of mixtures across a metamaterial membrane. The separation of mixtures into their constituent compounds is critically important in biophysics, biomedical, and chemical applications. We present a practical case where a mixture of oxygen and nitrogen diffusing through a polymeric planar matrix is separated. This work opens doors to new paradigms in membrane separations via coordinate transformations and metamaterials by introducing novel properties and unconventional mass diffusion phenomena.

  10. Fiber optic sodium and potassium sensing by using a newly synthesized squaraine dye in PVC matrix.

    PubMed

    Ertekin, Kadriye; Tepe, Mustafa; Yenigül, Berrin; Akkaya, Engin U; Henden, Emür

    2002-10-16

    In recent years squarines received attention as fluorescent labels. Their very promising spectral properties such as long wavelength absorption and emission, high extinction coefficients and quantum yields could lead novel sensing technologies. In this work newly synthesized fluoroinophores named bis[4-N-(1-aza-4,7,10,13-tetraoxacyclopentadecyl)-3,5-dihydroxyphenyl]squaraine, azacrown-1 and 2 bis[4-N-(1-aza-4,7,10,13,16-pentaoxacyclooctadecyl)-3,5-dihydroxyphenyl]squaraine, azacrown-2 have been used for sodium and potassium sensing in plasticized PVC matrix. The squaraine derivatives exhibited fluorescence emission based optical responses to sodium and potassium with a detection limit of 1.10(-9) M. The sensor compositions exhibited wide response ranges between 10(-9) and 10(-5) M Na(+)or K(+), and, therefore, may be an alternative method to flame emission spectroscopy. The sensor is fully reversible within the dynamic range and the response time is 3 min under batch conditions. Cross sensitivity to pH is negligible in the pH range of 6.2-7.3. Throughout fiber optic based studies a relative signal change of 54-56% has been achieved. The azacrown dyes have the advantage that they can be excited with long wavelength light and, are, therefore, LED compatible. The cross sensitivity of azacrown-1 and -2 to Ba(2+), Ca(2+) and NH(4)(+)were also tested in separate solutions.

  11. Analysis of toxic effluents released from PVC carpet under different fire conditions.

    PubMed

    Stec, A A; Readman, J; Blomqvist, P; Gylestam, D; Karlsson, D; Wojtalewicz, D; Dlugogorski, B Z

    2013-01-01

    A large number of investigations have been reported on minimising the PAH and PCDD/F yields during controlled combustion, such as incineration. This study is an attempt to quantify acute and chronic toxicants including PAH and PCDD/F in conditions relating to unwanted fires. This paper investigates distribution patterns of fire effluents between gas and aerosol phase, and the different particle size-ranges produced under different fire conditions. PVC carpet was selected as the fuel as a precursor for both PAH and PCDD/F. In order to generate fire effluents under controlled fire conditions, the steady-state tube furnace, was chosen as the physical fire model. Fire scenarios included oxidative pyrolysis, well-ventilated and under-ventilated fires. Fire effluent measurements included: carbon monoxide, carbon dioxide, hydrogen chloride, polycyclic aromatic hydrocarbons, chlorinated dibenzo-dioxins and furans and soot. The distribution patterns between gas and particle phase, and the size-ranges of the particles produced in these fires together with their chemical composition is also reported. Significant quantities of respirable submicron particles were detected, together with a range of PAHs. Lower levels of halogenated dioxins were detected in the fire residue compared with those found in other studies. Nevertheless, the findings do have implications for the health and safety of fire and rescue personnel, fire investigators, and other individuals exposed to the residue from unwanted fires.

  12. Co-occurrence of invasive Cuban Treefrogs and native treefrogs in PVC pipe refugia

    USGS Publications Warehouse

    Elston, Laura M.; Waddle, J. Hardin; Rice, Kenneth G.; Percival, H. Franklin

    2013-01-01

    The Cuban Treefrog (Osteopilus septentrionalis) was first introduced to Florida at Key West. Since this introduction, Cuban Treefrogs have spread to Miami and are now established throughout most of peninsular Florida. Cuban Treefrogs can become very abundant in areas they colonize. Several reasons contribute to their success, including a generalist diet, high fecundity and the ability to reproduce year-round, and use of disturbed or human-modified habitats. Scientists and managers are concerned that Cuban Treefrogs may contribute to the decline of native treefrogs. Cuban Treefrogs may exclude native treefrogs through both competition and predation. Because the evidence from our study and others suggests that Green and Squirrel Treefrogs do not alter their behavior to avoid Cuban Treefrogs, there is cause for concern that sampling with PVC pipes may increase the vulnerability of the native species to predation. This possibility needs further research, including whether other species of native treefrogs sympatric to where Cuban Treefrogs have invaded are also naïve to the possible threat posed by these frogs, and also if native treefrogs eventually learn to avoid Cuban Treefrogs.

  13. Acute health effects among firefighters exposed to a polyvinyl chloride (PVC) fire

    SciTech Connect

    Markowitz, J.S.; Gutterman, E.M. ); Schwartz, S.; Link, B.; Gorman, S.M. )

    1989-05-01

    Firefighters are frequently being called on to fight fires that are chemical in nature. In the aftermath of a chemical fire in Plainfield, New Jersey on March 20-21, 1985, the authors conducted a retrospective cohort study which surveyed 80 firefighters exposed to burning polyvinyl chloride (PVC) as well as 15 nonexposed firefighter subjects. By means of an 81-item symptom checklist, exposed firefighters reported more frequent and severe symptoms at 5-6 weeks post incident. This was true for a total symptomatology score as well as 19 individual items. Some of the items with an elevated risk were consistent with exposure to hydrogen chloride, the main pyrolysis product of polyvinyl chloride. Other items with an elevated risk appeared to be related to smoke inhalation while others seemed psychosocial in nature. Analyses conducted within the exposed firefighter group showed that fighting the fire the first day, being a truckman, and residence within 1 mile (1.6 km) of the firehouse were significant risk factors for high total symptom scores. These risk factors may have been associated with level or duration of exposure to the toxic substances produced during the fire.

  14. Reduced Staphylococcus aureus proliferation and biofilm formation on zinc oxide nanoparticle PVC composite surfaces.

    PubMed

    Seil, Justin T; Webster, Thomas J

    2011-06-01

    Conventional particulate zinc oxide (ZnO) is a known antibacterial agent. Studies have shown that reducing the size of ZnO particles to nanoscale dimensions further enhances their antibacterial properties. Polymers, like all biomaterials, run the risk of harboring bacteria which may produce an antibiotic-resistant biofilm. The addition of ZnO nanoparticles to form a polymer composite material may thus reduce undesirable bacteria activity. The purpose of the present in vitro study was to investigate the antibacterial properties of ZnO nanoparticles when incorporated into a traditional polymeric biomaterial. For this purpose, Staphylococcus aureus were seeded at a known cell density onto coverslips coated with a film of polyvinyl chloride (PVC) with varying concentrations of ZnO nanoparticles. Samples were cultured for 24 or 72 h. Methods of analysis, including optical density readings and crystal violet staining, indicated a reduced presence of a biofilm on ZnO nanoparticle polymer composites compared to pure polymer controls. Live/dead bacteria assays provided images to confirm the reduced presence of active bacteria on samples with zinc oxide nanoparticles. Conditioning of the cell culture medium by the composites was also investigated by measuring concentrations of elemental zinc (Zn(2+)) and bacteria growth in the presence of conditioned medium. This study demonstrated that the development of ZnO polymer composites may improve biomaterial effectiveness for numerous applications, such as endotracheal tubes, catheter and implanted biomaterials, which are prone to bacterial infection.

  15. Simulated neonatal exposure to DEHP and MEHP from PVC enteral nutrition products.

    PubMed

    Takatori, Satoshi; Okamoto, You; Kitagawa, Yoko; Hori, Shinjiro; Izumi, Shun-Ichiro; Makino, Tsunehisa; Nakazawa, Hiroyuki

    2008-03-20

    The leaching of di(2-ethylhexyl)phthalate (DEHP) and mono(2-ethylhexyl)phthalate (MEHP) from medical products made of polyvinyl-chloride (PVC) to enteral nutrition (EN) for neonatal patients was determined in a simulated study. The study simulated a typical case of EN administration to a neonatal patient (body weight, 3 kg) in a neonatal care unit (temperature, 25 degrees C); the medical products used were an irrigator and catheter containing DEHP (9.1-31.8%, w/w) as a plasticizer. The worst-case daily exposures of the neonatal patient to DEHP and MEHP by the administration of EN were estimated to be 148 and 3.72 microg/(kg day), respectively, as assessed from the levels of these compounds leaching from the medical products to the EN. The use of DEHP-free medical products reduced the exposure of DEHP and MEHP to the minimum levels contained in the EN at preparation. A transition to DEHP-free medical products for neonatal patients would be effective in reducing the exposure of neonatal patients to DEHP via EN administration.

  16. Degradation of PVC/rPLA Thick Films in Soil Burial Experiment

    NASA Astrophysics Data System (ADS)

    Nowak, Bożena; Rusinowski, Szymon; Chmielnicki, Blazej; Kamińska-Bach, Grażyna; Bortel, Krzysztof

    2016-10-01

    Some of the biodegradable polymers can be blended with a synthetic polymer to facilitate their biodegradation in the environment. The objective of the study was to investigate the biodegradation of thick films of poly(vinyl chloride)/recycled polylactide (PVC/rPLA). The experiments were carried out in the garden soil or in the mixture of garden soil and hydrocarbon-contaminated soil under laboratory conditions. Since it is widely accepted that the biosurfactants secreted by microorganisms enable biotransformation of various hydrophobic substances in the environment, it was assumed that the use of contaminated soil, rich in biosurfactant producing bacteria, may accelerate biodegradation of plastics. After the experimental period, the more noticeable weight loss of polymer films was observed after incubation in the garden soil. However, more pronounced changes in the film surface morphology and chemical structure as well as decrease of tensile strength were observed after incubation of films in the mixture of garden and contaminated soil. It turned out that as a result of competition between two distinct groups of microorganisms present in the mixture of garden and hydrocarbon-contaminated soils the number of microorganisms and their activity were lower than the activity of indigenous microflora of garden soil as well as the amount of secreted biosurfactants towards plastics.

  17. Membrane magic

    SciTech Connect

    Buecker, B.

    2005-09-01

    The Kansas Power and Light Co.'s La Cyne generating station has found success with membrane filtration water pretreatment technology. The article recounts the process followed in late 2004 to install a Pall Aria 4 microfilter in Unit 1 makeup water system at the plant to produce cleaner water for reverse osmosis feed. 2 figs., 2 photos.

  18. Stability study of fotemustine in PVC infusion bags and sets under various conditions using a stability-indicating high-performance liquid chromatographic assay.

    PubMed

    Dine, T; Khalfi, F; Gressier, B; Luyckx, M; Brunet, C; Ballester, L; Goudaliez, F; Kablan, J; Cazin, M; Cazin, J C

    1998-11-01

    The stability and compatibility of fotemustine, a nitrosourea anticancer agent, in 5% dextrose solution with polyvinyl chloride (PVC) containers and administration sets were studied under different conditions of temperature and light. The drug was diluted to 0.8 and 2 mg ml(-1) in 100 or 250 ml 5% dextrose injection solutions for 1-h simulated infusions using PVC bags and administration sets with protection from light. After preparation in the PVC bags containing 5% dextrose, fotemustine was also prepared at the same concentrations and stored at 4 degrees C for 48 h and at room temperature (22 degrees C) or at sunray exposure ( > 30 degrees C) over 8 h with or without protection from light. The solution samples were removed immediately at various time points of simulated infusions and storage, and stored at -20 degrees C until analysis. The physical compatibility with PVC and chemical stability in solution of fotemustine were assessed by visual examination and by measuring the concentration of the drug in duplicate using a stability-indicating high-performance chromatographic assay. When admixed with a 5% dextrose solution, fotemustine 2 and 0.8 mg ml(-1) was compatible and stable over 1-h of simulated infusion using PVC bags through PVC administration sets with protection from light. On the other hand, in the same diluent, fotemustine was compatible and stable with PVC bags for at least 8 h at 22 degrees C with protection from light and for at least 48 h at 4 degrees C with protection from light. There were no pH variation, no visual change, no color change, no visible precipitation and no loss of the drug. Conversely, when the solutions were exposed to light (ambient or solar), the drug concentration decreased rapidly, leading to the production of a degradation product as shown by mass spectral analysis and a discoloration of the solutions. Finally, in all cases, no DEHP (di-2-ethylhexyl phthalate) was detected in the injection solution.

  19. Plasticizer-level study of poly(vinyl chloride) ion-selective membranes.

    PubMed

    Simon, M A; Kusy, R P

    1996-03-01

    Highly plasticized poly(vinyl chloride) (PVC) membranes (200 per hundred resin [phr]) form the basis of one class of ion-selective electrodes (ISEs). In previous work on the mechanical properties of membranes, the optimal ratio of plasticizer level employed to minimal level required for complete plasticization (phr(exp)/phrmin) was found to be 2.0. The current study was designed to determine whether this ratio is necessary or sufficient for proper ISE function. Dynamic mechanical analysis (DMA) was used to examine the effects of five plasticizers on the dynamic mechanical properties of membranes at three frequencies (110, 11.0, and 1.1 Hz) as a function of temperature (-100 degrees C to +100 degrees C); dioctyl sebacate (DOS), epoxidized propylene glycol dioleate (PGDO), ortho-nitrophenyl octyl ether (o-NPOE), epoxidized soybean oil (ESO), and epoxidized linseed oil (ELO). The glass transition temperature of PVC, which was found to be +77.1 degrees C at 11.0 Hz, was depressed by the addition of 200 phr of each plasticizer from a high of -1.4 degrees C (PGDO at 110 Hz) to a low of -70.2 degrees C (DOS at 1.1 Hz). DMA and electromotive-force (EMF) measurements on membranes plasticized with o-NPOE through a range of phr(exp)/phrmin from 0.5 to 9.3 indicated that a "transition window" occurs between phr(exp)/phrmin of 2.0 and 3.3 in which the membranes change from minimally plasticized polymer films to predictable ion-selective membranes, coinciding with the optimal mechanical properties observed previously. Based on dynamic mechanical properties and EMF response data, the optimal phr(exp)/phrmin++ ratios for membranes as a function of plasticizer were proposed: 0.8 for ESO and ELO, 1.3 for PGDO, 1.7 for DOS, and 3.0 for o-NPOE.

  20. Reduction of Toxoplasma gondii Development Due to Inhibition of Parasite Antioxidant Enzymes by a Dinuclear Iron(III) Compound.

    PubMed

    Portes, J A; Souza, T G; dos Santos, T A T; da Silva, L L R; Ribeiro, T P; Pereira, M D; Horn, A; Fernandes, C; DaMatta, R A; de Souza, W; Seabra, S H

    2015-12-01

    Toxoplasma gondii, the causative agent of toxoplasmosis, is an obligate intracellular protozoan that can infect a wide range of vertebrate cells. Here, we describe the cytotoxic effects of the dinuclear iron compound [Fe(HPCINOL)(SO4)]2-μ-oxo, in which HPCINOL is the ligand 1-(bis-pyridin-2-ylmethyl-amino)-3-chloropropan-2-ol, on T. gondii infecting LLC-MK2 host cells. This compound was not toxic to LLC-MK2 cells at concentrations of up to 200 μM but was very active against the parasite, with a 50% inhibitory concentration (IC50) of 3.6 μM after 48 h of treatment. Cyst formation was observed after treatment, as indicated by the appearance of a cyst wall, Dolichos biflorus lectin staining, and scanning and transmission electron microscopy characteristics. Ultrastructural changes were also seen in T. gondii, including membrane blebs and clefts in the cytoplasm, with inclusions similar to amylopectin granules, which are typically found in bradyzoites. An analysis of the cell death pathways in the parasite revealed that the compound caused a combination of apoptosis and autophagy. Fluorescence assays demonstrated that the redox environment in the LLC-MK2 cells becomes oxidant in the presence of the iron compound. Furthermore, a reduction in superoxide dismutase and catalase activities in the treated parasites and the presence of reactive oxygen species within the parasitophorous vacuoles were observed, indicating an impaired protozoan response against these radicals. These findings suggest that this compound disturbs the redox equilibrium of T. gondii, inducing cystogenesis and parasite death.

  1. Reduction of Toxoplasma gondii Development Due to Inhibition of Parasite Antioxidant Enzymes by a Dinuclear Iron(III) Compound

    PubMed Central

    Portes, J. A.; Souza, T. G.; dos Santos, T. A. T.; da Silva, L. L. R.; Ribeiro, T. P.; Pereira, M. D.; Horn, A.; Fernandes, C.; DaMatta, R. A.; de Souza, W.

    2015-01-01

    Toxoplasma gondii, the causative agent of toxoplasmosis, is an obligate intracellular protozoan that can infect a wide range of vertebrate cells. Here, we describe the cytotoxic effects of the dinuclear iron compound [Fe(HPCINOL)(SO4)]2-μ-oxo, in which HPCINOL is the ligand 1-(bis-pyridin-2-ylmethyl-amino)-3-chloropropan-2-ol, on T. gondii infecting LLC-MK2 host cells. This compound was not toxic to LLC-MK2 cells at concentrations of up to 200 μM but was very active against the parasite, with a 50% inhibitory concentration (IC50) of 3.6 μM after 48 h of treatment. Cyst formation was observed after treatment, as indicated by the appearance of a cyst wall, Dolichos biflorus lectin staining, and scanning and transmission electron microscopy characteristics. Ultrastructural changes were also seen in T. gondii, including membrane blebs and clefts in the cytoplasm, with inclusions similar to amylopectin granules, which are typically found in bradyzoites. An analysis of the cell death pathways in the parasite revealed that the compound caused a combination of apoptosis and autophagy. Fluorescence assays demonstrated that the redox environment in the LLC-MK2 cells becomes oxidant in the presence of the iron compound. Furthermore, a reduction in superoxide dismutase and catalase activities in the treated parasites and the presence of reactive oxygen species within the parasitophorous vacuoles were observed, indicating an impaired protozoan response against these radicals. These findings suggest that this compound disturbs the redox equilibrium of T. gondii, inducing cystogenesis and parasite death. PMID:26392498

  2. Effect of high-dose electron beam irradiation on the migration of DOA and ATBC plasticizers from food-grade PVC and PVDC/PVC films, respectively, into olive oil.

    PubMed

    Goulas, A E; Riganakos, K A; Ehlermann, D A; Demertzis, P G; Kontominas, M G

    1998-06-01

    The effect of high-dose irradiation on the migration of dioctyl adipate (DOA) and acetyl tributyl citrate (ATBC) plasticizers from food-grade poly (vinyl chloride) (PVC) and poly (vinylidene chloride/vinyl chloride) (PVDC/PVC) copolymer (Saran) films, respectively, into olive oil was studied. The results showed a significantly higher amount of DOA migrated into olive oil from irradiated versus nonirradiated samples. This difference was more noticeable in oil samples collected during initial periods of contact. The amount of DOA migrating into olive oil was lower for samples irradiated at a dose of 20 kGy in comparison with samples irradiated at a dose of 50 kGy. At a sampling time of 1 h the amount of DOA that migrated into olive oil was 93.9 mg/liter, 141.5 mg/liter, and 183.4 mg/liter for nonirradiated samples, 20-kGy irradiated samples, and 50-kGy irradiated samples, respectively. After 288 hr (12 days) of oil-film contact the respective amounts were 390.8 mg/liter, 409.2 mg/liter, and 430.1 mg/liter. There were no statistically significant differences in migrating amount of ATBC between nonirradiated samples and samples irradiated at a dose of 20 kGy, while in samples irradiated at a dose of 50 kGy the migration of ATBC was increased. After 1 h of oil-film contact no detectable amounts of ATBC had migrated. After 288 h of contact the amounts of ATBC that migrated into olive oil were 3.59 mg/liter, 3.56 mg/liter, and 4.12 mg/liter for nonirradiated samples, 20-kGy irradiated samples, and 50-kGy irradiated samples, respectively. It is suggested that plasticized PVC should not be used in direct contact with high-fat foodstuffs with or without irradiation treatment.

  3. Rheology of PVC plastisol--VI: criteria for yielding and fracture of an immobilized layer.

    PubMed

    Nakajima, N; Harrell, E R

    2002-10-15

    PVC plastisol exhibits pseudo-plastic flow in steady shear; that is, viscosity decreases with the increasing shear rate. At higher shear rates viscosity reaches a minimum and then increases, i.e., dilatant behavior. Previously, pseudo-plastic behavior was explained by a mechanism in which the suspended particles partition into an immobilized layer and a mobile phase. The development of the immobilized layer with the increase in shear rate was shown to quantitatively account for pseudo-plastic behavior. In higher shear rates dilatation of the immobilized layer was shown to be the cause of dilatacy. At even higher shear rates the immobilized layer fractures. In this paper the viscosity minimum was interpreted as the yielding of the immobilized layer. Subsequently, data in the literature were analyzed to find criteria for the yielding and fracture of the immobilized layer. Yielding was found to obey Coulomb's criterion, from which the coefficient of friction and the cohesive strength of the immobilized layer were evaluated. These properties were controlled by the nature of particle assembly in the immobilized layer and the plasticizer type had only a minor effect. The value of the coefficient of friction was on the lower side and within the range of values found in the literature for other materials. There were two modes of fracture of the immobilized layer, one with low strength, low strain to break, and the other with high strength, high strain to break. The former is analogous to the brittle fracture of solids and the latter ductile failure. The strength of brittle fracture was somewhat higher than cohesive strength, which was evaluated from yielding data. This is akin to Griffith's criterion for brittle fracture of a solid. Ductile failure occurred when the shear stress exceeded normal stress.

  4. Rheology of PVC Plastisol--V: storage modulus and network formed by particle contact.

    PubMed

    Nakajima, N; Harrell, E R

    2002-10-15

    Our previous work with PVC plastisols showed that pseudo-plastic behavior under increasing frequency of dynamic measurement was a result of the development of an immobilized layer. Subsequently, the dynamic viscosity and the storage modulus of the mobile phase were evaluated. The samples consisted of fine and coarse particles, of which the fine/coarse ratio was varied. The present work relates the storage modulus at different frequencies to the fine/coarse ratio through a model network consisting of particle-particle contacts. The contacts are of three kinds, fine-fine (f-f), fine-coarse (f-c), and coarse-coarse (c-c). The average number of contact points per particle has been evaluated for the above kinds of contacts at different frequencies. Also, a number of particles participating in the network have been evaluated as a relative measure. At lower frequency relatively larger numbers of f-f contact points exist per particle but fewer numbers of particles participate in the network. Therefore, the network is rather loose. The f-c contact shows a similar trend but fewer contact points per particle at all frequency levels. The c-c contact is limited to a pair formation, i.e., only 0.5 contact point per particle on average. However, c-c contact contributes significantly to the magnitude of the modulus, because of the size of the particle. At the higher frequency there are fewer f-f contacts, but a larger number of particles are participating in the network. The trend with the f-c contact is very similar. The c-c contact increases significantly at the higher frequencies.

  5. Schiff's Bases and Crown Ethers as Supramolecular Sensing Materials in the Construction of Potentiometric Membrane Sensors

    PubMed Central

    Faridbod, Farnoush; Ganjali, Mohammad Reza; Dinarvand, Rassoul; Norouzi, Parviz; Riahi, Siavash

    2008-01-01

    Ionophore incorporated PVC membrane sensors are well-established analytical tools routinely used for the selective and direct measurement of a wide variety of different ions in complex biological and environmental samples. Potentiometric sensors have some outstanding advantages including simple design and operation, wide linear dynamic range, relatively fast response and rational selectivity. The vital component of such plasticized PVC members is the ionophore involved, defining the selectivity of the electrodes' complex formation. Molecular recognition causes the formation of many different supramolecules. Different types of supramolecules, like calixarenes, cyclodextrins and podands, have been used as a sensing material in the construction of ion selective sensors. Schiff's bases and crown ethers, which feature prominently in supramolecular chemistry, can be used as sensing materials in the construction of potentiometric ion selective electrodes. Up to now, more than 200 potentiometric membrane sensors for cations and anions based on Schiff's bases and crown ethers have been reported. In this review cation binding and anion complexes will be described. Liquid membrane sensors based on Schiff's bases and crown ethers will then be discussed. PMID:27879786

  6. Schiff's Bases and Crown Ethers as Supramolecular Sensing Materials in the Construction of Potentiometric Membrane Sensors.

    PubMed

    Faridbod, Farnoush; Ganjali, Mohammad Reza; Dinarvand, Rassoul; Norouzi, Parviz; Riahi, Siavash

    2008-03-11

    Ionophore incorporated PVC membrane sensors are well-established analyticaltools routinely used for the selective and direct measurement of a wide variety of differentions in complex biological and environmental samples. Potentiometric sensors have someoutstanding advantages including simple design and operation, wide linear dynamic range,relatively fast response and rational selectivity. The vital component of such plasticizedPVC members is the ionophore involved, defining the selectivity of the electrodes' complexformation. Molecular recognition causes the formation of many different supramolecules.Different types of supramolecules, like calixarenes, cyclodextrins and podands, have beenused as a sensing material in the construction of ion selective sensors. Schiff's bases andcrown ethers, which feature prominently in supramolecular chemistry, can be used assensing materials in the construction of potentiometric ion selective electrodes. Up to now,more than 200 potentiometric membrane sensors for cations and anions based on Schiff's bases and crown ethers have been reported. In this review cation binding and anioncomplexes will be described. Liquid membrane sensors based on Schiff's bases and crownethers will then be discussed.

  7. A development and biological safety evaluation of novel PVC medical devices with surface structures modified by UV irradiation to suppress plasticizer migration.

    PubMed

    Haishima, Yuji; Isama, Kazuo; Hasegawa, Chie; Yuba, Toshiyasu; Matsuoka, Atsuko

    2013-09-01

    This study examines the chemical, physicochemical, and biological properties of PVC sheets treated with UV irradiation on their surfaces to suppress the elution of a plasticizer, di-(2-ethylhexyl) phthalate (DEHP), for developing novel polyvinyl chloride (PVC) medical devices. The PVC sheets irradiated under conditions 1 (52.5 μW/cm(2), 136 J/cm(2)) and 2 (0.45 mW/cm(2), 972 J/cm(2)) exhibited considerable toxicity in cytotoxicity tests and chromosome aberration tests due to the generation of DEHP oxidants, but no toxicity was detected in the PVC sheet irradiated under condition 3 (8.3 mW/cm(2), 134 J/cm(2)). The release of DEHP from the surface irradiated under condition 3 was significantly suppressed, and mono-(2-ethylhexyl) phthalate (MEHP) converted from a portion of DEHP could be easily removed from the surface by washing with methanol. The physicochemical properties of the surface regarding the suppression of DEHP elution remained stable through all sterilizations tested, but MEHP elution was partially recrudesced by the sterilizations except for gamma irradiation. These results indicated that UV irradiation using a strong UV-source over a short time (condition 3) followed by methanol washing and gamma sterilization may be useful for preparing novel PVC products that did not elute plasticizers and do not exhibit toxicity originating from UV irradiation.

  8. Mimicking the intradiol catechol cleavage activity of catechol dioxygenase by high-spin iron(III) complexes of a new class of a facially bound [N2O] ligand.

    PubMed

    Panda, Manas K; John, Alex; Shaikh, Mobin M; Ghosh, Prasenjit

    2008-12-15

    A series of high-spin iron(III) complexes, {N-R-2-[(pyridin-2-ylmethyl)amino]acetamide}FeCl(3) [R = mesityl (1b), 2,6-Et(2)C(6)H(3) (2b), and 2,6-i-Pr(2)C(6)H(3) (3b)], that functionally emulate the intradiol catechol dioxygenase enzyme are reported. In particular, these enzyme mimics, 1b, 2b, and 3b, which utilized molecular oxygen in carrying out the intradiol catechol cleavage of 3,5-di-tert-butylcatechol with high regioselectivity (ca. 81-85%) at room temperature under ambient conditions, were designed by employing a new class of a facially bound [N(2)O] ligand, namely, N-R-2-[(pyridin-2-ylmethyl)amino]acetamide [R = mesityl (1a), 2,6-Et(2)C(6)H(3) (2a), and 2,6-i-Pr(2)C(6)H(3) (3a)]. The density functional theory studies revealed that the intradiol catechol cleavage reaction proceeded by an iron(III) peroxo intermediate that underwent 1,2-Criegee rearrangement to yield the intradiol catechol cleaved products analogous to the native enzyme.

  9. Evaluation of a predictive mathematical model of di-(2-ethylhexyl) adipate plasticizer migration from PVC film into foods.

    PubMed

    Mercer, A; Castle, L; Comyn, J; Gilbert, J

    1990-01-01

    The diffusion coefficient of the plasticizer di-(2-ethylhexyl)adipate (DEHA) in Cheddar cheese (Df) was determined by measuring the extent to which DEHA penetrated cheese that was placed in intimate contact with artificially DEHA-contaminated cheese. Slices (20 microns) of cheese from the boundary layer, into which DEHA had migrated, were microtomed at -40 degrees C, and analyzed for DEHA by gas chromatography (GC). Mean values of Df determined by graph fitting experimental and calculated data were 1.5 x 10(-9) cm2 s-1 at 5 degrees C and 3.0 x 10(-8) cm2 s-1 at 25 degrees C. The partition coefficient (K) of DEHA between cheese and PVC film was derived from the partition coefficients of DEHA between acetonitrile (ACN) and cheese lipid, ACN and cheese solid, and ACN and PVC film. The mean values of K between cheese and PVC film were estimated to be 0.70 at 5 degrees C and 0.58 at 25 degrees C. The estimated values of Df and K were then used in a mathematical model (Till et al. 1982) to predict migration levels of DEHA into cheese. Good agreement with previously published experimental data was obtained. Extrapolation of the prediction of DEHA migration into fatty foods, such as salami and avocado, was also successful (ratio of experimental to predicted results within a factor of two). The values of Df and K for cheese are, however, inappropriate for modelling non-fatty foods such as meat, cakes, fruit and vegetables. Predicted values for these foods were typically 3-10-fold too high. More accurate predictions would probably be obtained if values of Df more relevant to these foods are used. The predictions were relatively insensitive to the value of K.

  10. Mycelial fungi completely remediate di(2-ethylhexyl)phthalate, the hazardous plasticizer in PVC blood storage bag.

    PubMed

    Pradeep, S; Benjamin, Sailas

    2012-10-15

    This pioneering work describes how simply, inexpensively and efficiently novel fungi utilize the alarming plasticizer, di(2-ethylhexyl)phthalate (DEHP) blended in PVC blood storage bags (BB). In order to quantify total DEHP (33.5%, w/w) present in BB, it was extracted using n-hexane and confirmed by GC-MS. Three mycelial fungi, viz., Aspergillus parasiticus, Fusarium subglutinans and Penicillium funiculosum isolated in our laboratory form heavily plastics-contaminated soil - either singly or in consortium - completely consumed intact DEHP physically bound to BB by static submerged growth (28 °C) in simple basal salt medium (BSM). A two-stage cultivation strategy was adopted for the complete removal of DEHP from BB in situ. During the first growth stage, almost 70% DEHP contained in the BB was consumed in 2 weeks, accompanied by increased fungal biomass (~0.15-0.35 g/g BB; OD ~7 at 600 nm) and a sharp declining (3.3) of initial pH (7.2). Spent BSM was replaced at this stagnant growth state (low pH), thus in the second stage, remaining DEHP bound to BB utilized completely (over 99%). Furthermore, A. parasiticus and F. subglutinans also grew well on scrapes of PVC water pipes in BSM. F. subglutinans was as efficient independently as consortium in completely utilizing the DEHP bound to BB, and these fungi offer great potentials for the inexpensive and eco-friendly bioremediation of phthalates in medical and allied PVC wastes on a large scale through a batch process in alleviating the plactics waste management issue.

  11. The purified vepoloxamer prevents haemolysis in 42-day stored, DEHP/PVC-free red blood cell units

    PubMed Central

    Cancelas, Jose A.; Rugg, Neeta; Nestheide, Shawnagay; Hill, Sarah E.; Emanuele, R. Martin; McKenzie, Douglas S.

    2017-01-01

    Background Use of the plasticiser di(2-ethylhexyl) phthalate (DEHP) in polyvinyl chloride (PVC) blood bags poses a potential dilemma. The presence of DEHP in blood bags has been shown to be beneficial to red blood cells during storage by diminishing haemolysis. However, DEHP use in PVC may be carcinogenic or estrogenising. Vepoloxamer is a poloxamer with rheological and cytoprotective rheological properties and a favourable toxicity profile in clinical trials. We hypothesised that vepoloxamer may be sufficient to replace the plasticiser DEHP to prevent elevated haemolysis while conserving the biochemical and redox potential++ in RBCs stored for up to 42 days. Materials and methods Paired analyses of aliquots from pooled RBC suspensions of ABO identical donors were aseptically split into test storage containers (DEHP/PVC or DEHP-free/ethylene vinyl acetate [EVA]) supplemented with or without vepoloxamer (at concentrations of 0.1, 1, 5 or 7.89 mg/mL) and cold stored for up to 42 days. Results Vepoloxamer significantly prevented the increased haemolysis induced by the absence of DEHP in EVA bags in a dose-dependent manner by days 28 and 42 of storage (approx. 50% reduction of the maximum concentration of vepoloxamer; p<0.001). There was an inverse correlation between the concentration of vepoloxamer used and the haemolysis rate (r2=0.27, p<0.001) and a direct correlation between haemolysis and phosphatidylserine (PS) exposure (r2=0.42; p<0.01). Increased osmotic fragility and shear induced deformability of 42-day stored RBC in EVA bags was significantly corrected by the addition of vepoloxamer. Discussion Vepoloxamer, in a concentration-dependent fashion, is able to partly rescue the increased haemolysis and PS exposure induced by the absence of the commonly used plasticiser DEHP. These results provide initial but strong evidence to support vepoloxamer use to replace DEHP in long-term storage of RBC. PMID:28263175

  12. Selective sequential separation of ABS/HIPS and PVC from automobile and electronic waste shredder residue by hybrid nano-Fe/Ca/CaO assisted ozonisation process.

    PubMed

    Mallampati, Srinivasa Reddy; Lee, Byoung Ho; Mitoma, Yoshiharu; Simion, Cristian

    2017-02-01

    The separation of plastics containing brominated flame retardants (BFR) like (acrylonitrile-butadiene-styrene (ABS), high-impact polystyrene (HIPS), and polyvinyl chloride (PVC)) from automobile and electronic waste shredder residue (ASR/ESR) are a major concern for thermal recycling. In laboratory scale tests using a hybrid nano-Fe/Ca/CaO assisted ozonation treatment has been found to selectively hydrophilize the surface of ABS/HIPS and PVC plastics, enhancing ABS wettability and thereby promoting its separation from ASR/ESR by means of froth flotation. The water contact angles, of ABS/HIPS and PVC decreased, about 18.7°, 18.3°, and 17.9° in ASR and about 21.2°, 20.7°, and 20.0° in ESR respectively. SEM-EDS, FT-IR, and XPS analyses demonstrated a marked decrease in [Cl] and a significant increase in the number of hydrophilic groups, such as CO, CO, and (CO)O, on the PVC or ABS surface. Under froth flotation conditions at 50rpm, about 99.1% of combined fraction of ABS/HIPS in ASR samples and 99.6% of ABS/HIPS in ESR samples were separated as settled fraction. After separation, the purity of the recovered combined ABS/HIPS fraction was 96.5% and 97.6% in ASR and ESR samples respectively. Furthermore, at 150rpm a 100% PVC separation in the settled fraction, with 98% and 99% purity in ASR and ESR plastics, respectively. Total recovery of non-ABS/HIPS and PVC plastics reached nearly 100% in the floating fraction. Further, this process improved the quality of recycled ASR/ESR plastics by removing surface contaminants or impurities.

  13. Omniphobic Membrane for Robust Membrane Distillation

    SciTech Connect

    Lin, SH; Nejati, S; Boo, C; Hu, YX; Osuji, CO; Ehmelech, M

    2014-11-01

    In this work, we fabricate an omniphobic microporous membrane for membrane distillation (MD) by modifying a hydrophilic glass fiber membrane with silica nanoparticles followed by surface fluorination and polymer coating. The modified glass fiber membrane exhibits an anti-wetting property not only against water but also against low surface tension organic solvents that easily wet a hydrophobic polytetrafluoroethylene (PTFE) membrane that is commonly used in MD applications. By comparing the performance of the PTFE and omniphobic membranes in direct contact MD experiments in the presence of a surfactant (sodium dodecyl sulfate, SDS), we show that SDS wets the hydrophobic PTFE membrane but not the omniphobic membrane. Our results suggest that omniphobic membranes are critical for MD applications with feed waters containing surface active species, such as oil and gas produced water, to prevent membrane pore wetting.

  14. Kinetic analysis of 52Fe-labelled iron(III) hydroxide-sucrose complex following bolus administration using positron emission tomography.

    PubMed

    Beshara, S; Lundqvist, H; Sundin, J; Lubberink, M; Tolmachev, V; Valind, S; Antoni, G; Långström, B; Danielson, B G

    1999-02-01

    Kinetic analysis of a single intravenous injection of 100 mg iron(III) hydroxide-sucrose complex (Venofer) mixed with 52Fe(III) hydroxide-sucrose as a tracer was followed for 3-6 h in four generally anaesthetized, artificially ventilated minipigs using positron emission tomography (PET). The amount of injected radioactivity ranged from 30 to 200 MBq. Blood radioactivity, measured by PET in the left ventricle of the heart, displayed a fast clearance phase followed by a slow one. In the liver and bone marrow a fast radioactivity uptake occurred during the first 30 min, followed by a slower steady increase. In the liver a slight decrease in radioactivity uptake was noted by the end of the study. A kinetic analysis using a three-compartment (namely blood pool, reversible and irreversible tissue pools) model showed a fairly high distribution volume in the liver as compared with the bone marrow. In conclusion, the pharmacokinetics of the injected complex was clearly visualized with the PET technique. The organs of particular interest, namely the heart (for blood kinetics), liver and bone marrow could all be viewed by a single setting of a PET tomograph with an axial field of view of 10 cm. The half-life (T1/2) of 52Fe (8.3 h) enables a detailed kinetic study up to 24 h. A novel method was introduced to verify the actual 52Fe contribution to the PET images by removing the interfering radioactive daughter 52mMn positron emissions. The kinetic data fitted the three-compartment model, from which rate constants could be obtained for iron transfer from the blood to a pool of iron in bone marrow or liver to which it was bound during the study period. In addition, there was a reversible tissue pool of iron, which in the liver slowly equilibrated with the blood, to give a net efflux from the liver some hours after i.v. administration. The liver uptake showed a relatively long distribution phase, whereas the injected iron was immediately incorporated into the bone marrow. Various

  15. Selective Iron(III) ion uptake using CuO-TiO2 nanostructure by inductively coupled plasma-optical emission spectrometry

    PubMed Central

    2012-01-01

    Background CuO-TiO2 nanosheets (NSs), a kind of nanomaterials is one of the most attracting class of transition doped semiconductor materials due to its interesting and important optical, electrical, and structural properties and has many technical applications, such as in metal ions detection, photocatalysis, Chemi-sensors, bio-sensors, solar cells and so on. In this paper the synthesis of CuO-TiO2 nanosheets by the wet-chemically technique is reported. Methods CuO-TiO2 NSs were prepared by a wet-chemical process using reducing agents in alkaline medium and characterized by UV/vis., FT-IR spectroscopy, X-ray photoelectron spectroscopy (XPS), powder X-ray diffraction (XRD), and field-emission scanning electron microscopy (FE-SEM) etc. Results The structural and optical evaluation of synthesized NSs were measured by XRD pattern, Fourier transform infrared (FT-IR) and UV–vis spectroscopy, respectively which confirmed that the obtained NSs are well-crystalline CuO-TiO2 and possessing good optical properties. The morphological analysis of CuO-TiO2 NSs was executed by FE-SEM, which confirmed that the doped products were sheet-shaped and growth in large quantity. Here, the analytical efficiency of the NSs was applied for a selective adsorption of iron(III) ion prior to detection by inductively coupled plasma-optical emission spectrometry (ICP-OES). The selectivity of NSs towards various metal ions, including Au(III), Cd(II), Co(II), Cr(III), Fe(III), Pd(II), and Zn(II) was analyzed. Conclusions Based on the selectivity study, it was confirmed that the selectivity of doped NSs phase was the most towards Fe(III) ion. The static adsorption capacity for Fe(III) was calculated to be 110.06 mgg−1. Results from adsorption isotherm also verified that the adsorption process was mainly monolayer-adsorption onto a surface containing a finite number of CuO-TiO2 NSs adsorption sites. PMID:23244218

  16. Mechanistic study of iron(III) [tetrakis(pentafluorophenyl)porphyrin triflate (F(20)TPP)Fe(OTf) catalyzed cyclooctene epoxidation by hydrogen peroxide.

    PubMed

    Stephenson, Ned A; Bell, Alexis T

    2007-03-19

    We have recently proposed a mechanism for the epoxidation of cyclooctene by H2O2 catalyzed by iron(III) [tetrakis(pentafluorophenyl)]porphyrin chloride, (F20TPP)FeCl, in solvent containing methanol [Stephenson, N. A.; Bell, A.T. Inorg. Chem. 2006, 45, 2758-2766]. In that study, we found that catalysis did not occur unless (F20TPP)FeCl first dissociated, a process facilitated by the solvation of the Cl- anion by methanol and the coordination of methanol to the (F20TPP)Fe+ cation. Methanol as well as other alcohols was also found to facilitate the heterolytic cleavage of the O-O bond of H2O2 coordinated to the (F20TPP)Fe+ cation via a generalized acid mechanism. In the present study, we have shown that catalytic activity of the (F20TPP)Fe+ cation can be achieved in aprotic solvent by displacing the tightly bound chloride anion with a weakly bound triflate anion. By working in an aprotic solvent, acetonitrile, it was possible to determine the rate of heterolytic O-O bond cleavage in coordinated H2O2 unaffected by the interaction of the peroxide with methanol. A mechanism is proposed for this system and is shown to be valid over a range of reaction conditions. The mechanisms for cyclooctene epoxidation and H2O2 decomposition for the aprotic and protic solvent systems are similar with the only difference being the mechanism of proton-transfer prior to heterolytic cleavage of the oxygen-oxygen bond of coordinated hydrogen peroxide. Comparison of the rate parameters indicates that the utilization of hydrogen peroxide for cyclooctene epoxidation is higher in a protic solvent than in an aprotic solvent and results in a smaller extent of porphyrin degradation due to free radical attack. It was also shown that water can coordinate to the iron porphyrin cation in aprotic systems resulting in catalyst deactivation; this effect was not observed when methanol was present, since methanol was found to displace all of the coordinated water.

  17. Investigation of Ionic Conductivity of Nanocomposite Polymer Electrolytes Based On PVDF-HFP/PVC Blend, LiClO4 and TiO2 Nanofiller

    NASA Astrophysics Data System (ADS)

    Basri, N. H.; Mohamed, N. S.

    2010-07-01

    The effects of nanosized TiO2 on the conductivity of PVDF-HFP/PVC-LiClO4 was studied by means of impedance spectroscopy and x-ray diffraction (XRD). The addition of TiO2 nanofiller increases the crystalline phase fraction but slightly increases the conductivity of the PVDF-HFP/PVC-LiClO4 complex. The increase in conductivity is attributed to the formation of highly conducting layer at the electrolyte/filler interface. The temperature dependence of conductivity obeys the VTF type behaviour while the transference number confirms that the electrolyte containing 6 wt.% TiO2 is an ionic conductor are ionic conductors.

  18. Ferromagnetic coupling between low- and high-spin iron(III) ions in the tetranuclear complex fac-[[FeIII[HB(pz)3](CN)2(mu-CN)]3FeIII(H2O)3]* 6H2O ([HB(pz)3]- = hydrotris(1-pyrazolyl)borate).

    PubMed

    Lescouëzec, Rodrigue; Vaissermann, Jacqueline; Lloret, Francesc; Julve, Miguel; Verdaguer, Michel

    2002-11-18

    The novel mononuclear PPh4-fac-[FeIII[HB(pz)3](CN)3]*H2O (1) [PPh4+= tetraphenylphosphonium cation; (HB(pz)3)- = hydrotris(1-pyrazolyl)borate] and tetranuclear fac-[[FeIII[HB(pz)3](CN)2(mu-CN)]3FeIII(H2O)3]*6H2O (2) have been prepared and characterized by X-ray diffraction analysis. Crystal data for compound 1: monoclinic, space group P21/c, a = 9.575(3) A, b = 21.984(4) A, c = 16.863(3) A, beta = 100.34(2) degrees, U = 3486(1) A3, Z = 4. Crystal data for compound 2: orthorhombic, space group Pnam, a = 14.084(3) A, b = 14.799(4) A, c = 25.725(5) A, U = 5362(2) A3, Z = 4. Compound 1 is a low-spin iron(III) compound with three cyanide ligands in fac arrangement and a tridentate pyrazolylborate ligand building a distorted octahedral environment around the iron atom. Compound 2 is the first example of a molecular species containing three peripheral low-spin iron(III) ions linked to a central high-spin iron(III) cation by single cyanide bridges, the anion of 1 acting as a monodentate ligand in 2. Variable-temperature magnetic susceptibility measurements of 2 reveal the occurrence of a significant ferromagnetic coupling between the three peripheral low-spin iron(III) centers and the central high-spin iron(III) ion cations leading to a low-lying nonet spin state.

  19. Geometry of membrane fission.

    PubMed

    Frolov, Vadim A; Escalada, Artur; Akimov, Sergey A; Shnyrova, Anna V

    2015-01-01

    Cellular membranes define the functional geometry of intracellular space. Formation of new membrane compartments and maintenance of complex organelles require division and disconnection of cellular membranes, a process termed membrane fission. Peripheral membrane proteins generally control membrane remodeling during fission. Local membrane stresses, reflecting molecular geometry of membrane-interacting parts of these proteins, sum up to produce the key membrane geometries of fission: the saddle-shaped neck and hour-glass hemifission intermediate. Here, we review the fundamental principles behind the translation of molecular geometry into membrane shape and topology during fission. We emphasize the central role the membrane insertion of specialized protein domains plays in orchestrating fission in vitro and in cells. We further compare individual to synergistic action of the membrane insertion during fission mediated by individual protein species, proteins complexes or membrane domains. Finally, we describe how local geometry of fission intermediates defines the functional design of the protein complexes catalyzing fission of cellular membranes.

  20. Effect of an encapsulate carbon nanotubes (CNTs) on structural and electrical properties of PU/PVC nanocomposites

    NASA Astrophysics Data System (ADS)

    Abdelrazek, E. M.; Elashmawi, I. S.; Hezma, A. M.; Rajeh, A.; Kamal, Mustafa

    2016-12-01

    Nanocomposites samples of polyurethane and polyvinyl chloride (PU/PVC) loaded both multi and single walled-carbon nanotubes were synthesized by the casting technique. The X-ray analysis indicated that decrease degree of crystallinity after addition of carbon nanotubes (CNTs) due to interaction between CNTs and PU/PVC. The Transmission electron microscope (TEM) indicated encapsulation of polymer blend on CNTs surface. The highest value of AC conductivity was observed at high content of CNTs and frequency related effective conductive network formed when CNTs loaded in the blend. Whereas molecules of CNTs bridged between localized states and potential barrier. The permittivity (ε ‧) was decreased when the frequency increased due to direction dipoles of applied electric field. At high frequencies, the decreasing trend of permittivity seems nearly stable attributed to dipoles orientation. The higher value of dielectric loss (ε ″) was observed at low frequency due to the mobile charges within blend backbone. An increases of loss tangent (tan δ) with increasing in CNTs content was expected because conductivity increases with increasing CNTs. The decrease of tan δ with increasing frequency is attributed to the fact that the hopping frequency of charge carriers cannot follow any changes of externally applied electric field.

  1. Suspended micro-sized PVC particles impair the performance and decrease survival in the Asian green mussel Perna viridis.

    PubMed

    Rist, Sinja Elena; Assidqi, Khoirunnisa; Zamani, Neviaty Putri; Appel, Daniel; Perschke, Myriam; Huhn, Mareike; Lenz, Mark

    2016-10-15

    Marine bivalves are known to ingest microplastics, but information on the consequences for their physiological performance is limited. To investigate a potential exposure pathway that has not yet been addressed, we mimicked the resuspension of microplastics from the sediment in a laboratory exposure experiment. For this, we exposed the Asian green mussel Perna viridis to 4 concentrations (0mg/l, 21.6mg/l, 216mg/l, 2160mg/l) of suspended polyvinylchloride (PVC) particles (1-50μm) for two 2-hour-time-periods per day. After 44days, mussel filtration and respiration rates as well as byssus production were found to be a negative function of particle concentration. Furthermore, within 91days of exposure, mussel survival declined with increasing PVC abundance. These negative effects presumably go back to prolonged periods of valve closure as a reaction to particle presence. We suggest that microplastics constitute a new seston component that exerts a stress comparable to natural suspended solids.

  2. Isolation and molecular identification of landfill bacteria capable of growing on di-(2-ethylhexyl) phthalate and deteriorating PVC materials

    PubMed Central

    Latorre, Isomar; Hwang, Sangchul; Montalvo-Rodriguez, Rafael

    2012-01-01

    Waste materials containing Di-(2-ethylhexyl) phthalate (DEHP), a suspected endocrine disruptor and reasonably anticipated human carcinogen, are typically disposed of in landfills. Despite this, very few studies had been conducted to isolate and identify DEHP-degrading bacteria in landfill leachate. Therefore, this study was conducted to isolate and characterize bacteria in landfill leachate growing on DEHP as the sole carbon source and deteriorating PVC materials. Four strains LHM1, LHM2, LHM3 and LHM4, not previously reported as DEHP-degraders, were identified via 16S rRNA gene sequence. Gram-positive strains LHM1 and LHM2 had a greater than 97% similarity with Chryseomicrobium imtechense MW 10(T) and Lysinibacillus fusiformis NBRC 15717(T), respectively. Gram-negative strains LHM3 and LHM4 were related to Acinetobacter calcoaceticus DSM 30006(T) (90.7% similarity) and Stenotrophomonas pavanii ICB 89(T) (96.0% similarity), respectively. Phylogenetic analysis also corroborated these similarities of strains LHM1 and LHM2 to the corresponding bacteria species. Strains LHM2 and LHM4 grew faster than strains LHM1 and LHM3 in the enrichment where DEHP was the sole carbon source. When augmented to the reactors with PVC shower curtains containing DEHP, strains LHM1 and LHM2 developed greater optical densities in the solution phase and thicker biofilm on the surfaces of the shower curtains. PMID:22934997

  3. Optical properties of a long dynamic range chemical UV dosimeter based on solvent cast polyvinyl chloride (PVC).

    PubMed

    Amar, Abdurazaq; Parisi, Alfio V

    2013-11-05

    The dosimetric properties of the recently introduced UV dosimeter based on 16 μm PVC film have been fully characterised. Drying the thin film in air at 50 °C for at least 28 days was found to be necessary to minimise the temperature effects on the dosimeter response. This research has found that the dosimeter response, previously reported to be mainly to UVB, has no significant dependence on either exposure temperature or dose rate. The dosimeter has negligible dark reaction and responds to the UV radiation with high reproducibility. The dosimeter angular response was found to have a similar pattern as the cosine function but deviates considerably at angles larger than 70°. Dose response curves exhibit monotonically increasing shape and the dosimeter can measure more than 900 SED. This is about 3 weeks of continuous exposure during summer at subtropical sites. Exposures measured by the PVC dosimeter for some anatomical sites exposed to solar radiation for twelve consecutive days were comparable with those concurrently measured by a series of PPO dosimeters and were in line with earlier results reported in similar studies.

  4. Identification and quantification by (1)H nuclear magnetic resonance spectroscopy of seven plasticizers in PVC medical devices.

    PubMed

    Genay, Stéphanie; Feutry, Frédéric; Masse, Morgane; Barthélémy, Christine; Sautou, Valérie; Odou, Pascal; Décaudin, Bertrand; Azaroual, Nathalie

    2017-02-01

    Medical devices are generally made of polyvinyl chloride plasticized by six authorized plasticizers as alternatives to di-(2-ethylhexyl)-phthalate (DEHP) classified as reprotoxic class 1b. These are acetyl tri-n-butyl citrate (ATBC), di-(2-ethylhexy) adipate (DEHA), di-(2-ethylhexyl) terephthalate (DEHT), di-isononyl cyclohexane-1,2-dicarboxylate (DINCH), di-isononyl phthalate (DINP), and tri-octyl trimellitate (TOTM). The main objective of this study was to propose a new method using (1)H NMR spectroscopy to determine and quantify these seven plasticizers in PVC sheets, standard infusion tubings, and commercially available medical devices. Two techniques were compared: dissolution in deuterated tetrahydrofuran and extraction by deuterated chloroform. Plasticizer (1)H NMR spectra were very similar in both deuterated solvents; dissolution and extraction provided similar results. The sensitivity of this method enabled us to detect and quantify the presence of minor plasticizers in PVC. In nine commercially available samples, the major plasticizer was identified and quantified by (1)H NMR. In six samples, one, two, or three minor plasticizers were identified and also quantified. DEHP was detected in only one tubing. NMR is therefore very convenient for studying plasticizers contained in medical devices. Only small quantities of solvents and sample are required. It is not necessary to dilute samples to enter a quantification range, and it is sufficiently sensitive to detect contaminants.

  5. Effect of protein concentrations on the properties of fish myofibrillar protein based film compared with PVC film.

    PubMed

    Kaewprachu, Pimonpan; Osako, Kazufumi; Benjakul, Soottawat; Rawdkuen, Saroat

    2016-04-01

    The effect of protein concentrations on the properties of fish myofibrillar protein film (FMP) were investigated and compared with commercial wrap film (polyvinyl chloride; PVC). FMP (2 %, w/v) showed the highest mechanical properties [tensile strength: 4.38 MPa and elongation at break: 133.05 %], and water vapor permeability [2.81 × 10(-10) g m(-1) s(-1) Pa(-1)]. FMP contained high molecular weight cross-links, resulting in complex film network, as indicated by lower film solubility (19-22 %) and protein solubility (0.6-1.3 %). FMP showed excellent barrier properties to UV light at the wavelength of 200-280 nm. FMP had the thickness [0.007-0.032 mm], color attributes and transparency similar to PVC film [thickness: 0.010 mm]. Therefore, protein concentration majority influenced the properties of develop FMP. The protein content of 1 % (w/v) had potential to be developed the biodegradable film with comparable properties to the commercial wrap film.

  6. Anion permselective membrane

    NASA Technical Reports Server (NTRS)

    Hodgdon, R. B.; Waite, W. A.

    1980-01-01

    The efforts on the synthesis of polymer anion redox membranes were mainly concentrated in two areas, membrane development and membrane fabrication. Membrane development covered the preparation and evaluation of experimental membranes systems with improved resistance stability and/or lower permeability. Membrane fabrication covered the laboratory scale production of prime candidate membranes in quantities of up to two hundred and sizes up to 18 inches x 18 inches (46 cm x 46 cm). These small (10 in x 11 in) and medium sized membranes were mainly for assembly into multicell units. Improvements in processing procedures and techniques for preparing such membrane sets lifted yields to over 90 percent.

  7. Influence of nonionic surfactants on the potentiometric response of hydrogen ion-selective polymeric membrane electrodes.

    PubMed

    Espadas-Torre, C; Bakker, E; Barker, S; Meyerhoff, M E

    1996-05-01

    The influence of poly(ethylene oxide)-based nonionic surfactants (i.e., Triton X-100 and Brij 35) in the sample phase on the response properties of hydrogen ion-selective polymeric membrane electrodes containing mobile (lipophilic amines) or covalently bound (aminated-poly-(vinyl chloride)) hydrogen ion carriers is reported. In the presence of these nonionic surfactants, membrane electrode response toward interfering cation activity (e.g., Na+) in the sample phase is increased substantially and the pH measuring range shortened. The degree of cation interference for pH measurements is shown to correlate with the basicity of the hydrogen ion carrier doped within the membrane phase. The observed deterioration in selectivity arises from the partitioning of the surfactant into the membrane and concomitant extraction of metal cations by the surfactants in the organic phase. The effect of nonionic surfactants on pH electrodes prepared with aminated-PVC membranes is shown to be more complex, with additional large shifts in EMF values apparently arising from multidentate interactions between the surfactant molecules and the polymeric amine in the membrane, leading to a change in the apparent pKa values for the amine sites. The effects induced by nonionic surfactants on the EMF response function of hydrogen ion-selective polymeric membrane electrodes are modeled, and experimental results are shown to correlate well with theoretical predictions.

  8. Magnetic Membrane System

    DOEpatents

    McElfresh, Michael W.; ; Lucas, Matthew S.

    2004-12-30

    The present invention provides a membrane with magnetic particles. In one embodiment the membrane is created by mixing particles in a non-magnetic base. The membrane may act as an actuator, a sensor, a pump, a valve, or other device. A magnet is operatively connected to the membrane. The magnet acts on and changes the shape of the membrane.

  9. Electrodriven selective transport of Cs+ using chlorinated cobalt dicarbollide in polymer inclusion membrane: a novel approach for cesium removal from simulated nuclear waste solution.

    PubMed

    Chaudhury, Sanhita; Bhattacharyya, Arunasis; Goswami, Asok

    2014-11-04

    The work describes a novel and cleaner approach of electrodriven selective transport of Cs from simulated nuclear waste solutions through cellulose tri acetate (CTA)/poly vinyl chloride (PVC) based polymer inclusion membrane. The electrodriven cation transport together with the use of highly Cs+ selective hexachlorinated derivative of cobalt bis dicarbollide, allows to achieve selective separation of Cs+ from high concentration of Na+ and other fission products in nuclear waste solutions. The transport selectivity has been studied using radiotracer technique as well as atomic emission spectroscopic technique. Transport studies using CTA based membrane have been carried out from neutral solution as well as 0.4 M HNO3, while that with PVC based membrane has been carried out from 3 M HNO3. High decontamination factor for Cs+ over Na+ has been obtained in all the cases. Experiment with simulated high level waste solution shows selective transport of Cs+ from most of other fission products also. Significantly fast Cs+ transport rate along with high selectivity is an interesting feature observed in this membrane. The current efficiency for Cs+ transport has been found to be ∼100%. The promising results show the possibility of using this kind of electrodriven membrane transport methods for nuclear waste treatment.

  10. Removal of chromium(VI) from aqueous solutions by polymer inclusion membranes.

    PubMed

    Kozlowski, Cezary A; Walkowiak, Wladyslaw

    2002-11-01

    The transport through polymer inclusion membranes (PIMs) was found as the effective and selective method of chromium(VI) anions removal from chloride acidic aqueous solutions. The optimal PIMs content was as follows: 41 wt% of cellulose triacetate as the support, 23 wt% of tri-n-octylamine as the ionic carrier, and 36 wt% of o-nitrophenyl pentyl ether as the plasticizer. The results obtained show a linear decrease of permeability coefficient and initial flux values with source phase pH increase. Also linear decrease of initial flux in log-log scale with chromium(VI) concentration increase was observed. Value of slope of this relationship was found to be 0.96 which indicates a first order of chromium(VI) reaction with tri-n-octylamine at membrane/aqueous source interface. Transport of chromium(VI) through PIMs reduces the concentration of chromium(VI) in source aqueous phase from 1.0 to 0.0028 ppm, which is below permissible limit in drinking water in Poland. Competitive transport of chromium(VI), cadmium(II), zinc(II), and iron(III) from acidic aqueous solution across PIMs was found to be efficient for chromium(VI) (99%), and cadmium(II) (99%).

  11. The Effect of Zn-Al-Hydrotalcites Composited with Calcium Stearate and β-Diketone on the Thermal Stability of PVC

    PubMed Central

    Tong, Mengliang; Chen, Hongyan; Yang, Zhanhong; Wen, Runjuan

    2011-01-01

    A clean-route synthesis of Zn-Al-hydrotalcites (Zn-Al-LDHs) using zinc oxide and sodium aluminate solution has been developed. The as-obtained materials were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and scanning electron microscopy (SEM). The effects of metal ions at different molar ratios on the performance of hydrotalcites were discussed. The results showed that the Zn-Al-hydrotalcites can be successfully synthesized at three different Zn/Al ratios of 3:1, 2:1 and 1:1. Thermal aging tests of polyvinyl chloride (PVC) mixed with Zn-Al-LDHs, calcium stearate (CaSt2) and β-diketone were carried out in a thermal aging test box by observing the color change. The results showed that Zn-Al-LDHs can not only enhance the stability of PVC significantly due to the improved capacity of HCl-adsorption but also increase the initial stability and ensure good-initial coloring due to the presence of the Zn element. The effects of various amounts of Zn-Al-LDHs, CaSt2 and β-diketone on the thermal stability of PVC were discussed. The optimum composition was determined to be 0.1 g Zn-Al-LDHs, 0.15 g CaSt2 and 0.25 g β-diketone in 5 g PVC. PMID:21673921

  12. The effect of Zn-Al-hydrotalcites composited with calcium stearate and β-diketone on the thermal stability of PVC.

    PubMed

    Tong, Mengliang; Chen, Hongyan; Yang, Zhanhong; Wen, Runjuan

    2011-01-01

    A clean-route synthesis of Zn-Al-hydrotalcites (Zn-Al-LDHs) using zinc oxide and sodium aluminate solution has been developed. The as-obtained materials were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and scanning electron microscopy (SEM). The effects of metal ions at different molar ratios on the performance of hydrotalcites were discussed. The results showed that the Zn-Al-hydrotalcites can be successfully synthesized at three different Zn/Al ratios of 3:1, 2:1 and 1:1. Thermal aging tests of polyvinyl chloride (PVC) mixed with Zn-Al-LDHs, calcium stearate (CaSt(2)) and β-diketone were carried out in a thermal aging test box by observing the color change. The results showed that Zn-Al-LDHs can not only enhance the stability of PVC significantly due to the improved capacity of HCl-adsorption but also increase the initial stability and ensure good-initial coloring due to the presence of the Zn element. The effects of various amounts of Zn-Al-LDHs, CaSt(2) and β-diketone on the thermal stability of PVC were discussed. The optimum composition was determined to be 0.1 g Zn-Al-LDHs, 0.15 g CaSt(2) and 0.25 g β-diketone in 5 g PVC.

  13. Preparation and Properties of Double-Sided AgNWs/PVC/AgNWs Flexible Transparent Conductive Film by Dip-Coating Process.

    PubMed

    Chen, Cui-Yu; Jing, Mao-Xiang; Pi, Zhi-Chao; Zhu, Sheng-Wen; Shen, Xiang-Qian

    2015-12-01

    The double-sided transparent conductive films of AgNWs/PVC/AgNWs using the silver nanowires and PVC substrate were fabricated by the dip-coating process followed by mechanical press treatment. The morphological and structural characteristics were investigated by scanning electron microscope (SEM) and atomic force microscope (AFM), the photoelectric properties and mechanical stability were measured by ultraviolet-visible spectroscopy (UV-vis) spectrophotometer, four-point probe technique, 3M sticky tape test, and cyclic bending test. The results indicate that the structure and photoelectric performances of the AgNWs films were mainly affected by the dipping and lifting speeds. At the optimized dipping speed of 50 mm/min and lifting speed of 100 mm/min, the AgNWs are evenly distributed on the surface of the PVC substrate, and the sheet resistance of AgNWs film on both sides of PVC is about 60 Ω/sq, and the optical transmittance is 84.55 % with the figure of merit value up to 35.8. The film treated with the 10 MPa pressure shows excellent adhesion and low surface roughness of 17.8 nm and maintains its conductivity with the sheet resistance change of 17 % over 10,000 cyclic bends.

  14. Preparation and Properties of Double-Sided AgNWs/PVC/AgNWs Flexible Transparent Conductive Film by Dip-Coating Process

    NASA Astrophysics Data System (ADS)

    Chen, Cui-yu; Jing, Mao-xiang; Pi, Zhi-chao; Zhu, Sheng-wen; Shen, Xiang-qian

    2015-08-01

    The double-sided transparent conductive films of AgNWs/PVC/AgNWs using the silver nanowires and PVC substrate were fabricated by the dip-coating process followed by mechanical press treatment. The morphological and structural characteristics were investigated by scanning electron microscope (SEM) and atomic force microscope (AFM), the photoelectric properties and mechanical stability were measured by ultraviolet-visible spectroscopy (UV-vis) spectrophotometer, four-point probe technique, 3M sticky tape test, and cyclic bending test. The results indicate that the structure and photoelectric performances of the AgNWs films were mainly affected by the dipping and lifting speeds. At the optimized dipping speed of 50 mm/min and lifting speed of 100 mm/min, the AgNWs are evenly distributed on the surface of the PVC substrate, and the sheet resistance of AgNWs film on both sides of PVC is about 60 Ω/sq, and the optical transmittance is 84.55 % with the figure of merit value up to 35.8. The film treated with the 10 MPa pressure shows excellent adhesion and low surface roughness of 17.8 nm and maintains its conductivity with the sheet resistance change of 17 % over 10,000 cyclic bends.

  15. A MIXTURE OF ORGANOTINS FOUND IN POLYVINYL CHLORIDE (PVC) PIPE IS NOT IMMUNOTOXIC TO SPRAGUE-DAWLEY RATS WHEN GIVEN IN DRINKING WATER

    EPA Science Inventory

    Organotin compounds used in PVC pipe production are of concern to the U.S. EPA because they leach from supply pipes into drinking water and are reported multisystem toxicants. We assessed immune functions in male Sprague-Dawley rats exposed to the mixture of organotins used in P...

  16. Membrane Systems in Cyanobacteria

    SciTech Connect

    Liberton, Michelle L.; Pakrasi, Himadri B.

    2008-01-01

    Cyanobacteria are photosynthetic prokaryotes with highly differentiated membrane systems. In addition to a Gram-negative-type cell envelope with plasma membrane and outer membrane separated by a periplasmic space, cyanobacteria have an internal system of thylakoid membranes where the fully functional electron transfer chains of photosynthesis and respiration reside. The presence of different membrane systems lends these cells a unique complexity among bacteria. Cyanobacteria must be able to reorganize the membranes, synthesize new membrane lipids, and properly target proteins to the correct membrane system. The outer membrane, plasma membrane, and thylakoid membranes each have specialized roles in the cyanobacterial cell. Understanding the organization, functionality, protein composition and dynamics of the membrane systems remains a great challenge in cyanobacterial cell biology.

  17. Sensory aspects and water quality impacts of chlorinated and chloraminated drinking water in contact with HDPE and cPVC pipe.

    PubMed

    Heim, Timothy H; Dietrich, Andrea M

    2007-02-01

    Pipes constructed with high-density polyethylene (HDPE) or chlorinated polyvinyl chloride (cPVC) are commonly used in drinking water distribution systems and premise plumbing. In this comprehensive investigation, the effects on odor, organic chemical release, trihalomethane (THM) formation, free chlorine demand and monochloramine demand were determined for water exposed to HDPE and cPVC pipes. The study was conducted in accordance with the Utility Quick Test (UQT), a migration/leaching protocol for analysis of materials in contact with drinking water. The sensory panel consistently attributed a weak to moderate intensity of a "waxy/plastic/citrus" odor to the water from the HDPE pipes but not the cPVC-contacted water samples. The odor intensity generated by the HDPE pipe remained relatively constant for multiple water flushes, and the odor descriptors were affected by disinfectant type. Water samples stored in both types of pipe showed a significant increase in the leaching of organic compounds when compared to glass controls, with HDPE producing 0.14 microgTOC/cm(2) pipe surface, which was significantly greater than the TOC release from cPVC. Water stored in both types of pipe showed disinfectant demands of 0.1-0.9 microg disinfectant/cm(2) pipe surface, with HDPE exerting more demand than cPVC. No THMs were detected in chlorinated water exposed to the pipes. The results demonstrate the impact that synthetic plumbing materials can have on sensory and chemical water quality, as well as the significant variations in drinking water quality generated from different materials.

  18. Electrochemical impedance spectroscopy-a simple method for the characterization of polymer inclusion membranes containing aliquat 336.

    PubMed

    O'Rourke, Michelle; Duffy, Noel; Marco, Roland De; Potter, Ian

    2011-06-23

    Electrochemical impedance spectroscopy (EIS) has been used to estimate the non-frequency dependent (static) dielectric constants of base polymers such as poly(vinyl chloride) (PVC), cellulose triacetate (CTA) and polystyrene (PS). Polymer inclusion membranes (PIMs) containing different amounts of PVC or CTA, along with the room temperature ionic liquid Aliquat 336 and plasticizers such as trisbutoxyethyl phosphate (TBEP), dioctyl sebecate (DOS) and 2-nitrophenyloctyl ether (NPOE) have been investigated. In this study, the complex and abstract method of EIS has been applied in a simple and easy to use way, so as to make the method accessible to membrane scientists and engineers who may not possess the detailed knowledge of electrochemistry and interfacial science needed for a rigorous interpretation of EIS results. The EIS data reported herein are internally consistent with a percolation threshold in the dielectric constant at high concentrations of Aliquat 336, which illustrates the suitability of the EIS technique since membrane percolation with ion exchangers is a well-known phenomenon.

  19. Effect of low molecular weight additives on immobilization strength, activity, and conformation of protein immobilized on PVC and UHMWPE.

    PubMed

    Kondyurin, Alexey; Nosworthy, Neil J; Bilek, Marcela M M

    2011-05-17

    Horseradish peroxidase (HRP) was immobilized onto both plasticized and unplasticized polyvinylchloride (PVC) and ultrahigh molecular weight polyethylene (UHMWPE). Plasma immersion ion implantation (PIII) in a nitrogen plasma with 20 kV bias was used to facilitate covalent immobilization and to improve the wettability of the surfaces. The surfaces and immobilized protein were studied using attenuated total reflection infrared (ATR-IR) spectroscopy and water contact angle measurements. Protein elution on exposure to repeated sodium dodecyl sulfate (SDS) washing was used to assess the strength of HRP immobilization. The presence of low molecular weight components (plasticizer, additives in solvent, unreacted monomers, adsorbed molecules on surface) was found to have a major influence on the strength of immobilization and the conformation of the protein on the samples not exposed to the PIII treatment. A phenomenological model considering interactions between the low molecular weight components, the protein molecule, and the surface is developed to explain these observations.

  20. Materials based on cellulose fabric and PVC with porous structures formed by jointed aza- and oxa-aza-crown macromolecules

    NASA Astrophysics Data System (ADS)

    Fridman, A. Ya.; Tsivadze, A. Yu.; Morozova, E. M.; Sokolova, N. P.; Shiryaev, A. A.; Petukhova, G. A.; Voloshchuk, A. M.; Bardyshev, I. I.; Gorbunov, A. M.; Polyakova, I. Ya.; Novikov, A. K.; Titova, V. N.; Yavich, A. A.; Petrova, N. V.

    2016-12-01

    A material with porous structures formed by jointed aza- and oxa-aza-crowns with peripheral OHgroups is synthesized on the basis of cellulose fabric and PVC transformed into hydroxyethylcyclam. Mesopores are mainly observed on the fiber surface. The specific surface of the material is 6 m2/g; the volume of free space is 0.112 cm3/g. Assuming the internal pores have a disk-like shape, their width is estimated at 2 nm. The material sorbs vapors of aliphatic and aromatic hydrocarbons, alcohols, aldehydes, ketones, amines, amides, nitriles, and sulfoxides. It also swells to a limited degree in organic solvents. When sulfuric acid or sodium hydroxide is sorbed in the pores, compounds of them with H+- and OH--conducting systems of hydrogen bonds are formed.

  1. An investigation of PVdF/PVC-based blend electrolytes with EC/PC as plasticizers in lithium battery applications

    NASA Astrophysics Data System (ADS)

    Rajendran, S.; Sivakumar, P.

    2008-03-01

    Solid polymer electrolytes (SPEs) composed of poly(vinylidene fluoride) (PVdF)-poly(vinyl chloride) (PVC) complexed with lithium perchlorate (LiClO 4) as salt and ethylene carbonate (EC)/propylene carbonate (PC) as plasticizers were prepared using solvent-casting technique, with different weight ratios of EC and PC. The amorphicity and complexation behavior of the polymer electrolytes were confirmed using X-ray diffraction (XRD) and FTIR studies. TG/DTA and scanning electron microscope (SEM) studies explained the thermal stability and surface morphology of electrolytes, respectively. The prepared thin films were subjected to AC impedance measurements as a function of temperature ranging from 302 to 373 K. The temperature-dependence conductivity of polymer films seems to obey VTF relation.

  2. The influence of CO(2) on ISFETs with polymer membranes and characterization of a carbonate ion sensor.

    PubMed

    Abramova, Natalia; Levichev, Sergey; Bratov, Andrey

    2010-06-15

    The influence of CO(2) and acetic acid on the response of ISFET sensors with PVC and photocured polyurethane polymer membranes with valinomycin as an ionophore was assessed. Experimental results show that the presence of these compounds has no effect on sensors parameters even after prolonged soaking in a water solution. Using a photocured polyurethane polymer as an ion-selective membrane matrix for an ISFET, a carbonate ion sensor was developed with hexyl-p-trifluoroacetylbenzoate (HE) as an ionophore. Effect of cationic and anionic lipophilic additives on the sensors response was studied. Sensors with the optimized membrane composition based on HE (7.9%, w/w) and tridodecylmethylammonium chloride (5.7%, w/w) show sensitivity of 27-30mV per decade of carbonate ion concentration, sufficient selectivity in front of chloride ions, and a lifetime of 3-5 months.

  3. Composite sensor membrane

    DOEpatents

    Majumdar, Arun; Satyanarayana, Srinath; Yue, Min

    2008-03-18

    A sensor may include a membrane to deflect in response to a change in surface stress, where a layer on the membrane is to couple one or more probe molecules with the membrane. The membrane may deflect when a target molecule reacts with one or more probe molecules.

  4. Membrane position control

    NASA Technical Reports Server (NTRS)

    Su, Ji (Inventor); Harrison, Joycelyn S. (Inventor)

    2004-01-01

    A membrane structure includes at least one electroactive bending actuator fixed to a supporting base. Each electroactive bending actuator is operatively connected to the membrane for controlling membrane position. Any displacement of each electroactive bending actuator effects displacement of the membrane. More specifically, the operative connection is provided by a guiding wheel assembly and a track, wherein displacement of the bending actuator effects translation of the wheel assembly along the track, thereby imparting movement to the membrane.

  5. Nanoporous Membrane Immunosensor

    DTIC Science & Technology

    2000-01-01

    Another aspect of the invention is a method for detecting an analyte in a test sample, having 5 the steps: (a) modifying a side of a semipermeable... side of the membrane with the membrane modifiers; (c) drawing the test sample through the membrane, osmotically or with the application of...immunoassay labels on the side of the membrane with the membrane modifiers, where these labels have label binding ligands where these label binding

  6. Sheet Membrane Spacesuit Water Membrane Evaporator

    NASA Technical Reports Server (NTRS)

    Bue, Grant; Trevino, Luis; Zapata, Felipe; Dillion, Paul; Castillo, Juan; Vonau, Walter; Wilkes, Robert; Vogel, Matthew; Frodge, Curtis

    2013-01-01

    A document describes a sheet membrane spacesuit water membrane evaporator (SWME), which allows for the use of one common water tank that can supply cooling water to the astronaut and to the evaporator. Test data showed that heat rejection performance dropped only 6 percent after being subjected to highly contaminated water. It also exhibited robustness with respect to freezing and Martian atmospheric simulation testing. Water was allowed to freeze in the water channels during testing that simulated a water loop failure and vapor backpressure valve failure. Upon closing the backpressure valve and energizing the pump, the ice eventually thawed and water began to flow with no apparent damage to the sheet membrane. The membrane evaporator also serves to de-gas the water loop from entrained gases, thereby eliminating the need for special degassing equipment such as is needed by the current spacesuit system. As water flows through the three annular water channels, water evaporates with the vapor flowing across the hydrophobic, porous sheet membrane to the vacuum side of the membrane. The rate at which water evaporates, and therefore, the rate at which the flowing water is cooled, is a function of the difference between the water saturation pressure on the water side of the membrane, and the pressure on the vacuum side of the membrane. The primary theory is that the hydrophobic sheet membrane retains water, but permits vapor pass-through when the vapor side pressure is less than the water saturation pressure. This results in evaporative cooling of the remaining water.

  7. Synthesis, siderophore activity and iron(III) chelation chemistry of a novel mono-hydroxamate, bis-catecholate siderophore mimic: N(alpha),-N(epsilon)-Bis[2,3-dihydroxybenzoyl]-l-lysyl-(gamma-N-methyl-N-hydroxyamido)-L-glutamic acid.

    PubMed

    Mies, Kassy A; Gebhardt, Peter; Möllmann, Ute; Crumbliss, Alvin L

    2008-04-01

    The synthesis and characterization of a novel tripodal mono-hydroxamate, bis catecholate siderophore mimic, N(alpha),-N(epsilon)-bis[2,3-dihydroxybenzoyl]-l-lysyl-(gamma-N-methyl-N-hydroxyamido)-l-glutamic acid (H(6)L), is described. The structure of H(6)L was established by 2D NMR and mass spectrometry. The chelation chemistry of H(6)L with respect to iron(III) is characterized in aqueous solution through determination of ligand pK(a) values and iron(III) binding constants using spectrophotometric and potentiometric titration techniques. Proton dependent iron(III)-ligand equilibrium constants were determined using a model based on the sequential protonation of the iron(III)-siderophore complex. These results were used to calculate the pH dependent speciation, the overall formation constant logbeta(110) (31.4) and pM value (18.3) for H(6)L with iron(III). The ability of H(6)L to deliver the essential nutrient iron to living cells is determined through growth promotion assays using various bacterial strains.

  8. A novel ethacrynic acid sensor based on a lanthanide porphyrin complex in a PVC matrix.

    PubMed

    Zhang, X B; Guo, C C; Xu, J B; Shen, G L; Yu, R Q

    2000-05-01

    Lanthanide porphyrin complexes synthesized by a solid state method were used to prepare a novel ethacrynic acid (EA) sensor. The sensor, based on pentane-2,4-dionato(meso-tetraphenylporphinato)terbium [TbTPP(acac)] with an optimized membrane composition, exhibits a Nernstian response to EA- ion in the concentration range 7.4 x 10(-6)-1.0 x 10(-1) mol l-1 with a pH range from 3.2 to 6.8 and a fast response time of 30 s. The electrode shows improved selectivity towards EA- ion with respect to common co-existing ions compared with the previously reported EA sensor. As electroactive materials, lanthanide porphyrin complexes show better potentiometric response characteristics than copper porphyrin complexes. The effect of solvent mediators and lipophilic ion additives was studied and the experimental conditions were optimized. The electrode was applied to the determination of EA in human urine samples with satisfactory results.

  9. Membrane selectivity in pervaporation

    SciTech Connect

    Kujawski, W.

    1996-06-01

    A qualitative description is presented of pervaporation which discusses the initial preferential sorption into the membrane, diffusion of liquid, phase transition from liquid to vapor phase, followed by diffusion of vapors and fast desorption from the other side of the membrane. The overall separation of each pervaporation step was calculated in terms of separation factor {alpha}. The results show that in the case of hydrophilic membranes (i.e., dense polyamide-6 membrane and ion-exchange membrane PESS-1) and water-ethanol mixtures, the phase transition step decreases the overall separation. Also, diffusion through the membrane is unfavorable to water at a low concentration range.

  10. Effect of nano CdS dispersion on thermal conductivity of PS/PVC and PS/PMMA polymeric blend nanocomposites

    NASA Astrophysics Data System (ADS)

    Mathur, Vishal; Patidar, Dinesh; Sharma, Kananbala

    2014-09-01

    The effect of dispersion of CdS nano-filler particles in respective PS/PVC and PS/PMMA polymer blend matrices on the effective thermal conductivity has been studied through Hot Disk Thermal Constant Analyzer based on transient plane source (TPS) technique. The thick film samples have been prepared by dispersing nano-filler particles of CdS (6 wt%) in respective PS/PVC and PS/PMMA binary blend matrices. The nanocomposite nature of prepared samples ascertained through small angle X-ray scattering (SAXS) as well as transmission electron microscopy (TEM) measurements. It is observed that at room temperature nano CdS dispersed polymeric blend samples offer higher effective thermal conductivity.

  11. Electrical conductivity and spectroscopic characterization of Blends of poly(2-chloroaniline)/polyaniline P(2ClANI)/PANI copolymer with PVC exposed to gamma-rays

    NASA Astrophysics Data System (ADS)

    Sevil, Uğur Adnan; Coşkun, Emel; Güven, Olgun

    2014-01-01

    Poly(2-chloroaniline)/polyaniline P(2ClANI)/PANI) random copolymer was synthesized in the form of nanoparticles by chemical routes. Incorporation of P(2ClANI) into PANI backbone significantly increased the solubility of copolymer in THF. Thin PVC/P(2ClANI)/PANI blend films were prepared by solvent casting and subsequently exposed to gamma-rays. Conductivity measurements on the irradiated blend films of PVC/P(2ClANI)/PANI showed that conductivity was increased from 10-8 S/cm to 10-5 S/cm when irradiated to radiation dose of up to 200 kGy. The increase in conductivity was also revealed by FTIR and UV-vis spectra.

  12. Effect of nano CdS dispersion on thermal conductivity of PS/PVC and PS/PMMA polymeric blend nanocomposites

    NASA Astrophysics Data System (ADS)

    Mathur, Vishal; Patidar, Dinesh; Sharma, Kananbala

    2015-06-01

    The effect of dispersion of CdS nano-filler particles in respective PS/PVC and PS/PMMA polymer blend matrices on the effective thermal conductivity has been studied through Hot Disk Thermal Constant Analyzer based on transient plane source (TPS) technique. The thick film samples have been prepared by dispersing nano-filler particles of CdS (6 wt%) in respective PS/PVC and PS/PMMA binary blend matrices. The nanocomposite nature of prepared samples ascertained through small angle X-ray scattering (SAXS) as well as transmission electron microscopy (TEM) measurements. It is observed that at room temperature nano CdS dispersed polymeric blend samples offer higher effective thermal conductivity.

  13. Covalently linked plasticizers: triazole analogues of phthalate plasticizers prepared by mild copper-free “click” reactions with azide-functionalized PVC.

    PubMed

    Earla, Aruna; Braslau, Rebecca

    2014-03-01

    Copper-free azide-alkyne click chemistry is utilized to covalently modify polyvinyl chloride(PVC). Phthalate plasticizer mimics di(2-ethylhexyl)-1H-triazole-4,5 dicarboxylate (DEHT), di(nbutyl)-1H-1,2,3-triazole-4,5-dicarboxylate (DBT), and dimethyl-1H-triazole-4,5-dicarboxylate(DMT) are covalently attached to PVC. DEHT, DBT, and DMT have similar chemical structures to traditional plasticizers di(2-ethylhexyl) phthalate (DEHP), di(n-butyl) phthalate (DBP), and dimethyl phthalate (DMP), but pose no danger of leaching from the polymer matrix and forming small endocrine disrupting chemicals. The synthesis of these covalent plasticizers is expected to be scalable, providing a viable alternative to the use of phthalates, thus mitigating dangers to human health and the environment.

  14. The novel approach to Cd(II) extraction by polymer inclusion membrane using TIOA as carrier

    NASA Astrophysics Data System (ADS)

    Polat, Cüneyt; Eyüpoǧlu, Volkan; Sara, Osman Nuri

    2016-04-01

    In the present study, the novel approach for the extraction of Cd(II) from acidic iodide solutions was achieved by using PVC based polymer inclusion membrane (PIM) technique containing triisooctyl amine (TIOA) as a carrier. PIMs were prepared according to the literature (1) and characterized by in aspects of thickness and surface morphology and molecular characterization. PIM composition was varied to find optimum membrane formation on Cd(II) transport. The effective parameters like thickness, plasticizer type and rate and carrier rate were investigated. Also, as a useful parameter, the concentration in the feed phase was examined to assess the effect on optimized membrane compositions. It was found that the concentration was the most useful parameter in the aqueous phase of Cd(II) transport because the remained I- in the aqueous feed phase unreacted with Cd(II). We recognize that by the time free I- concentration in the feed, the accumulation of the membrane increases and loading capacity of the membrane with CdI42- decreases because of the limited amount of carrier molecules in the PIM. As a result, it is concluded that extraction and separation of Cd(II) from simulated Ni/Cd leach solutions was carried out with higher initial mass transfer and permeation coefficients as 9,07×10-7 mol/m2s and 1,02×10-5 m/s at the optimum conditions respectively.

  15. Development of a simple method for predicting the levels of di(2-ethylhexyl) phthalate migrated from PVC medical devices into pharmaceutical solutions.

    PubMed

    Haishima, Yuji; Seshimo, Fumie; Higuchi, Tae; Yamazaki, Haruko; Hasegawa, Chie; Izumi, Shun-ichiro; Makino, Tsunehisa; Nakahashi, Keisuke; Ito, Rie; Inoue, Koichi; Yoshimura, Yoshihiro; Saito, Koichi; Yagami, Takeshi; Tsuchiya, Toshie; Nakazawa, Hiroyuki

    2005-07-14

    This study deals with the development of a simple method for predicting the elution levels of di-2-ethylhexyl phthalate (DEHP) from medical devices made of polyvinyl chloride (PVC) by using the physicochemical properties of pharmaceutical injections as a marker. GC-MS analysis showed that the release of DEHP from medical grade PVC product was concentration-dependently increased by extraction with two kinds of lipophilic injections (Sandimmun and Prograf) and three kinds of surfactants (HCO-60, Tween 80, and SDS). The solubility of lipophilic pigments such as Sudan III, methyl yellow, and 1,4-diamino-anthraquinone against these solutions were also increased in a concentration-dependent manner, in which methyl yellow showed the highest response regarding the increase of optical density (O.D.). Further, electrical conductivity and static contact angle to the PVC sheet of the solutions were also increased or decreased in the same manner. As a result of the comparative study, significant correlation was found between DEHP release levels and these three physicochemical properties, particularly methyl yellow solubility, of the solutions tested. To evaluate the relationship in detail, DEHP release levels from PVC tubing and methyl yellow solubility of 53 injections used in gynecologic and obstetric fields were determined. None of the hydrophilic medicines showed any significant release of DEHP, and all showed low solubility of methyl yellow. On the other hand, the lipophilic medicines releasing a large amount of DEHP showed high solubility of methyl yellow (greater than O.D. 0.8). These results indicate that a significant proportional relationship exists between DEHP release potency and methyl yellow solubility of pharmaceutical solutions, and the risk of DEHP exposure to the patients administered pharmaceuticals through transfusion set could be easily predicted by the solubility test without complicated elution tests of DEHP using GC-MS or LC-MS.

  16. Migration of di(2-ethylhexyl) adipate and acetyltributyl citrate plasticizers from food-grade PVC film into sweetened sesame paste (halawa tehineh): kinetic and penetration study.

    PubMed

    Goulas, Antonios E; Zygoura, Panagiota; Karatapanis, Andreas; Georgantelis, Dimitris; Kontominas, Michael G

    2007-04-01

    Food-grade polyvinyl chloride (PVC) cling-film containing 5.3% (w/w) di(2-ethylhexyl) adipate (DEHA) and 3.0% (w/w) acetyltributyl citrate (ATBC) plasticizers was used to wrap halawa tehineh (halva) samples. Samples were split into two groups and stored at 25+/-1 degrees C. One group was analyzed for DEHA and ATBC content at intervals between 0.5 and 240h of contact (kinetic study) and a second group was cut into slices (1.5mm thick) after 240h of halva/PVC contact and was analyzed for DEHA and ATBC content (penetration study). Determination of both plasticizers was performed using a direct gas chromatographic (GC) method after extraction of DEHA from halva samples. DEHA readily migrated into halva samples: the equilibrium amount of DEHA in halva (3.31mg/dm(2) film or 81.4mg/kg halva) corresponding to a loss of 54.7% (w/w) DEHA from PVC film. This value is slightly higher than the limit of 3mg/dm(2) of film surface set by the European Union for DEHA. The equilibrium amount of ATBC in halva was 1.46mg/dm(2) (36.1mg/kg) corresponding to a loss of 42.7% ATBC from PVC film. With regard to the penetration of both placticizers into halva samples, migration of DEHA was detectable up to the 7th slice beneath the surface of halva (total depth 10.5mm) while the migration of ATBC was detectable up to the 5th slice (total depth 7.5mm).

  17. Mechanisms of Membrane Preparation and Membrane Assays.

    DTIC Science & Technology

    The course of the work for the report period involved: Evaluating and developing testing procedures for membrane filters, and the construction, procurement of equipment for such testing; and Numerous sol preparations and castings of membranes using the acetate-butyrate esters of cellulose in lieu of the cellulose acetate in conjunction with the cellulose nitrate base of formulation. (Author)

  18. Forward and reverse (retro) iron(III) or gallium(III) desferrioxamine E and ring-expanded analogues prepared using metal-templated synthesis from endo-hydroxamic acid monomers.

    PubMed

    Lifa, Tulip; Tieu, William; Hocking, Rosalie K; Codd, Rachel

    2015-04-06

    A metal-templated synthesis (MTS) approach was used to preorganize the forward endo-hydroxamic acid monomer 4-[(5-aminopentyl)(hydroxy)amino]-4-oxobutanoic acid (for-PBH) about iron(III) in a 1:3 metal/ligand ratio to furnish the iron(III) siderophore for-[Fe(DFOE)] (ferrioxamine E) following peptide coupling. Substitution of for-PBH with the reverse (retro) hydroxamic acid analogue 3-(6-amino-N-hydroxyhexanamido)propanoic acid (ret-PBH) furnished ret-[Fe(DFOE)] (ret-ferrioxamine E). As isomers, for-[Fe(DFOE)] and ret-[Fe(DFOE)] gave identical mass spectrometry signals ([M + H(+)](+), m/zcalc 654.3, m/zobs 654.3), yet for-[Fe(DFOE)] eluted in a more polar window (tR = 23.44 min) than ret-[Fe(DFOE)] (tR = 28.13 min) on a C18 reverse-phase high-performance liquid chromatography (RP-HPLC) column. for-[Ga(DFOE)] (tR = 22.99 min) and ret-[Ga(DFOE)] (tR = 28.11 min) were prepared using gallium(III) as the metal-ion template and showed the same trend for the retention time. Ring-expanded analogues of for-[Fe(DFOE)] and ret-[Fe(DFOE)] were prepared from endo-hydroxamic acid monomers with one additional methylene unit in the amine-containing region, 4-[(6-aminohexyl)(hydroxy)amino]-4-oxobutanoic acid (for-HBH) or 3-(7-amino-N-hydroxyheptanamido)propanoic acid (ret-HBH), to give the corresponding tris(homoferrioxamine E) macrocycles, for-[Fe(HHDFOE)] or ret-[Fe(HHDFOE)] ([M + H(+)](+), m/zcalc 696.3, m/zobs 696.4). The MTS reaction using a constitutional isomer of for-HBH that transposed the methylene unit to the carboxylic acid containing region, 5-[(5-aminopentyl)(hydroxy)amino]-5-oxopentanoic acid (for-PPH), gave the macrocycle for-[Fe(HPDFOE)] in a yield significantly less than that for for-[Fe(HHDFOE)], with the gallium(III) analogue for-[Ga(HPDFOE)] unable to be detected. The work demonstrates the utility and limits of MTS for the assembly of macrocyclic siderophores from endo-hydroxamic acid monomers. Indirect measures (RP-HPLC order of elution, c log P values

  19. Migration of dioctyladipate plasticizer from food-grade PVC film into chicken meat products: effect of gamma-radiation.

    PubMed

    Goulas, A E; Kontominas, M G

    1996-03-01

    Food-grade PVC film containing 28.3% dioctyladipate (DOA) plasticizer was used to wrap chicken meat samples, with and without skin, contained in a polystyrene tray. Samples were then irradiated with gamma-radiation [60Co] at doses equal to 4 kGy and 9 kGy corresponding to "cold pasteurization". Irraddiation was carried out at 8-10 degrees C and samples were subsequently stored at 4-5 degrees C. Contaminated chicken meat samples were analysed for DOA at intervals between 7 h and 240 h of contact, using an indirect GC method. Identical non-irradiated (control) samples were also analysed for their DOA content. Results showed no statistically significant differences in migrated amounts of DOA between irradiated and non-irradiated samples. Neither were differences observed between samples irradiated at 4 kGy and 9 kGy. This was supported by identical IR spectra recorded for irradiated and non-irradiated samples and leads to the conclusion that, at such intermediate radiation doses ( < or = kGy), the migration characteristics of PVC film are not affected. DOA migration was found to be time dependent, approaching equilibrium after approximately 170 h for the chicken flesh plus skin samples and 120 h for the chicken flesh samples. The amount of DOA migrated into chicken flesh plus skin samples was significantly greater (3.2-22.3 mg/dm2) than that for chicken flesh samples (0.9-8.9 mg/dm2). After 240 h of sample/film contact under refrigeration, loss of DOA was approximately 35.6% for chicken flesh plus skin samples and 14.3% for chicken flesh samples. Sample spoilage, as demonstrated by off-odour development, occurred after approximately 120 h of refrigerated storage. Diffusion coefficients for DOA were calculated and were found to be lower for chicken flesh (1 x 10(-13) than for flesh plus skin (4.4 x 10(-13)) samples.

  20. Specific migration of di-(2-ethylhexyl)adipate (DEHA) from plasticized PVC film: results from an enforcement campaign.

    PubMed

    Petersen, J H; Breindahl, T

    1998-07-01

    A control campaign on the correct labelling of plasticized PVC film according to current legislation on food contact materials has been performed. Analytical methods based on the isotope dilution technique were developed. For enforcement purposes, the films were exposed to the official food simulant, olive oil, followed by clean-up using size exclusion chromatography and final determination of di-(2-ethylhexyl) adipate (DEHA) by combined capillary gas chromatography and mass spectrometry (GC-MS). In the initial screening, the samples were exposed to the alternative food simulant, isooctane, and DEHA could be determined by GC-MS without further clean-up. A good consistency between results from the two different methods was obtained. During the campaign, 49 samples of PVC films, the majority intended for use in retail shops, were sampled from importers and wholesalers by the Municipal Food Control Units. Initially, all films were screened for the migration into isooctane (exposed 2 h at 40 degrees C) of DEHA and other potentially present low molecular weight plasticizers using full scanning mass spectrometry. Films showing a substantial migration of DEHA were further tested with olive oil according to the declared field of application (exposed for 10 days at 40 degrees C). In 47 of the 49 films the migrate contained a substantial amount of DEHA. In 46 films the migration exceeded the specific migration limit of 3 mg/dm2 after use of the relevant reduction factor given in legislation. However, because of the general uncertainty of the analytical method and because the variation in the thickness of the films was calculated to be 1 mg/dm2, the action limit in this campaign was 4 mg/cm2. A migration higher than this action limit was found in 42 films (89% of the samples) and these films were deemed to be illegal according to their present declared field of application as given by their labelling. In a few cases, some migration of the plasticizer di-n-butyl phthalate was

  1. Equilibrium and kinetic modeling of iron adsorption and the effect by chloride, sulfate, and hydroxyl: evaluation of PVC-U drinking pipes.

    PubMed

    Wang, Jia -Ying; Li, Shu-Ping; Xin, Kun-Lun; Tao, Tao

    2016-12-01

    The update of pipeline was quick over the last few years and the plastic pipes were widely used in the drinking water distribution systems (DWDSs), especially in the small-diameter pipes. In this study, the iron adsorptive characteristics and the affecting factors in unplasticized poly(vinyl chloride) (PVC-U) pipe were investigated. Results showed that the average amount of iron in the 10-year-old PVC-U pipe's interior surface was 2.80 wt% which was almost 187 times larger than that in a new one. Goethite (α-FeOOH) and magnetite (Fe3O4) were the major iron compounds in the scales which covered on the old pipes' interior surface and showed loose and porous images under a scanning electron microscope. Moreover, the influence of the iron concentration on the adsorption amount and rate was discussed. The adsorption amount was significantly influenced by iron concentration, but similar adsorption rate was discovered. Notably, iron was quantitatively adsorbed by PVC-U pipe during the experimental period in accordance with the pseudo second order kinetic model. Meanwhile, regression model and response surface methodology were used to analyze the regular of iron adsorption in different concentrations of chloride (Cl(-)), sulfate (SO4(2-)), and hydroxyl (OH(-)). It can be concluded that Cl(-) and OH(-) showed the strong ability of iron adsorption which were larger than SO4(2-).

  2. The evaluation of Candida albicans biofilms formation on silicone catheter, PVC and glass coated with titanium dioxide nanoparticles by XTT method and ATPase assay.

    PubMed

    Haghighi, F; Mohammadi, Sh R; Mohammadi, P; Eskandari, M; Hosseinkhani, S

    2012-01-01

    Lots of Candida albicans infections involve in biofilm formation on medical devices. This kind of biofilm can impede antifungal therapy and complicates the treatment of infectious diseases particularly in field of chronic diseases associated with implanted devices. This study has investigated the influence of treating silicone catheter, PVC and glass coated with Titanium dioxide (TiO2) nanoparticles on attachment of C. albicans. In this study TiO2 nanoparticles were synthesized from precursor TiCl4 and characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD) which showed TiO2 nanoparticles are 70-100 nm in size. In the simplest model of biofilms formation, C. albicans isolates (ATCC10231) and (ATCC 76615) were grown on the surface of small disks of catheter, PVC and glass in a flat-bottomed 12-well plates and evaluated biofilm formation using ATP bioluminescence and tetrazolium salt (XTT) reduction assays. In addition, morphology of C. albicans biofilms after 48 h incubation was observed by SEM. Results indicated that there is a statistical difference between mean of coated samples especially catheter and glass before and after TiO2 nanoparticles coating (p<0.05). In SEM analysis, C. albicans biofilm was more aggregated on the surface of glass and catheter than PVC and control groups and after treatment by these nanoparticles, catheter and glass both showed most significant decrease of C. albicans attachment in comparison to the control groups (Fig. 4, Ref. 23).

  3. Adhesion of Pseudomonas aeruginosa strains to untreated and oxygen-plasma treated poly(vinyl chloride) (PVC) from endotracheal intubation devices.

    PubMed

    Triandafillu, K; Balazs, D J; Aronsson, B-O; Descouts, P; Tu Quoc, P; van Delden, C; Mathieu, H J; Harms, H

    2003-04-01

    Pseudomonas aeruginosa pneumonia is a life threatening complication in mechanically ventilated patients that requires the ability of the bacteria to adhere to, and colonize the endotracheal intubation device. New strategies to prevent or reduce these nosocomial infections are greatly needed. We report here the study of a set of P. aeruginosa clinical isolates, together with specific mutants, regarding their adhesion on native and chemically modified poly(vinyl chloride) (PVC) surfaces from endotracheal intubation devices. The adhesion of the different strains to untreated PVC varied widely, correlating with several physico-chemical characteristics known to influence the attachment of bacteria to inert surfaces. The adhesion patterns were compared to the calculations obtained with the DLVO theory of colloidal stability. These results illustrate the importance of testing different clinical isolates when investigating bacterial adhesion. Oxygen plasma treatment of the PVC pieces yielded a hydrophilic surface and reduced the number of adhering bacteria by as much as 70%. This reduction is however unlikely to be sufficient to prevent P. aeruginosa colonization of endotracheal intubation devices.

  4. Degradation mechanism and kinetic model for photocatalytic oxidation of PVC-ZnO composite film in presence of a sensitizing dye and UV radiation.

    PubMed

    Chakrabarti, Sampa; Chaudhuri, Basab; Bhattacharjee, Sekhar; Das, Paramita; Dutta, Binay Kanti

    2008-06-15

    White or plastic pollution has become a serious concern to the environmentalists for the last few years. Degradation of waste plastics in conventional incinerators leads to emission of carcinogenic dioxins to the atmosphere. In this work, an attempt has been made for the photocatalytic degradation of polyvinyl chloride (PVC) using ZnO as semi-conductor catalyst in the form of PVC-ZnO composite film. The surface morphology as well as the FTIR spectroscopy of the irradiated film has been critically examined. The degradation was measured by weight loss data and was found to follow a pseudo-first order rate equation. The various parameters studied were loading of the semi-conductor, intensity of UV radiation and presence of Eosin Y as a sensitizing dye. It was observed that dye-sensitization enhanced degradation of PVC to a large extent. A possible mechanism has been suggested and the corresponding rate equation has been modeled for the dye-sensitized rate of degradation. The model has been validated by the experimental data.

  5. Evaluation of the effect of the concentration of plasticizer di(2-ethylhexyl) phthalate on the quantity of residual monomer vinyl chloride in PVC chest drainage tubes.

    PubMed

    Kicheva, Y I; Richter, H; Popova, E

    2004-08-01

    The effect of amount of plasticizer di(2-ethylhexyl) phthalate (DEHP) amount on the amount of residual monomer vinyl chloride (VC) was determined in samples of plasticised polyvinyl chloride (PVC) with different concentration of plasticiser (22.32-33.05%), before and after sterilisation by a titrimetric method. The titrimetric method was used to determine the VC concentration in a KMnO4 solution where the samples were kept immersed under the same conditions for 2 h. The influence of PVC film extracts with different amounts of DEHP on mouse fibroblast cells L-929 in a culture medium was evaluated by using quantitative tests: the amount of cells (protein determination), viability (MTT test) and proliferation (incorporation of bromodeoxyuridine (BrDU). The amount of vinyl chloride before and after heat sterilisation at 120 degrees C for 30 min was found to be almost the same for all samples and without any dependence on the concentration of DEHP. The extracts of the PVC films which were tested have no toxic effect on cells in a culture medium.

  6. Multiresidual LC-MS analysis of plasticizers used in PVC gaskets of lids and assessment of their migration into food sauces.

    PubMed

    Lambertini, F; Catellani, D; Vindigni, M; Suman, M

    2016-09-01

    Plasticizers may migrate from polyvinyl chloride (PVC) gaskets into the foodstuffs mainly by direct contact during the packaging and sterilization procedure, but also by means of occasional contacts occurring during shipment and storage. The present work reports a reliable liquid chromatography-mass spectrometry (LC-MS) method able to quantify the main plasticizers used in the PVC closure gaskets for metal lids to verify their compliance in both food contact materials and foodstuffs. The atmospheric pressure chemical ionization in the positive ion mode resulted the best performing interface for the multiresidual detection of the plasticizers taken into account, followed by selected/multiple reaction monitoring, selected ion monitoring or full scan experiments, depending on the compounds to detect. The method was single-laboratory validated, demonstrating to reach a good sensitivity, thus making possible to perform analysis without any preliminary sample purification or concentration step. It proved to be effectively applicable not only for the determination of plasticizers in PVC gaskets but also in complex food matrices. In particular, it was applied for monitoring plasticizer migration into sauces placed in contact with the lids in worst storage conditions, observing therefore their trend during the shelf-life. Copyright © 2016 John Wiley & Sons, Ltd.

  7. Synergistic anti-biofouling effect of Ag-exchanged zeolite and D-Tyrosine on PVC composite against the clinical isolate of Acinetobacter baumannii.

    PubMed

    Milenkovic, Jelena; Hrenovic, Jasna; Goic-Barisic, Ivana; Tomic, Milos; Djonlagic, Jasna; Rajic, Nevenka

    2014-09-01

    Due to their susceptibility to bacterial biofilm formation, commercial tubes for medical use are one of the main sources of hospital infections with Acinetobacter baumannii. The anti-biofouling activity of novel composites against the clinical isolate of the multi-drug resistant A. baumannii is reported here. The composites were prepared by addition of micronised silver-exchanged natural zeolite (Ag-NZ) into poly(vinyl chloride) (PVC), followed by coating of the composites with D-Tyrosine (D-Tyr). The Ag-NZ composites (containing 1-15 wt% of Ag-NZ) coated with D-Tyr (Ag-NZ-Tyr) showed a bactericidal effect (100% or a 6.9 log CFU reduction) towards immobilised bacterial cells. The uncoated Ag-NZ composites showed a reduction of up to 70% (4.4 log CFU) of immobilised bacteria in comparison with the original PVC. Rheological testing of the composites revealed that the addition of Ag-NZ slightly affected processability and formability of the PVC and increased the elasticity of the polymer matrix.

  8. Enhanced performance of mixed-matrix membranes through a graft copolymer-directed interface and interaction tuning approach.

    PubMed

    Chi, Won Seok; Kim, Sang Jin; Lee, Seung-Joon; Bae, Youn-Sang; Kim, Jong Hak

    2015-02-01

    Herein, a high performance mixed-matrix membrane (MMM) is reported with simultaneously large improvements in the CO2 permeability by 880 % from 70.2 to 687.7 Barrer (1 Barrer=1×10(-10)  cm(3)  cm cm(-2)  s(-1)  cmHg(-1) ) and CO2 /N2 selectivity by 14.4 % from 30.5 to 34.9. These findings represent one of the most dramatic improvements ever reported for MMMs. These improvements are obtained through an interface and interaction tuning approach based on an amphiphilic grafted copolymer. Poly(vinyl chloride)-g-poly(oxyethylene methacrylate) (PVC-g-POEM) graft copolymer plays a key role as a soft organic matrix to provide good permeation properties, uniform distribution of zeolite imidazole frameworks-8 (ZIF-8), and better interfacial contact with inorganic compounds. In particular, the CO2 /C3 H8 and CO2 /C3 H6 selectivities reached 10.5 and 42.7, respectively, for PVC-g-POEM/ZIF (40 %) MMMs; this indicates that it could be a promising membrane material for the purification of C3 hydrocarbons.

  9. Supported inorganic membranes

    DOEpatents

    Sehgal, Rakesh; Brinker, Charles Jeffrey

    1998-01-01

    Supported inorganic membranes capable of molecular sieving, and methods for their production, are provided. The subject membranes exhibit high flux and high selectivity. The subject membranes are substantially defect free and less than about 100 nm thick. The pores of the subject membranes have an average critical pore radius of less than about 5 .ANG., and have a narrow pore size distribution. The subject membranes are prepared by coating a porous substrate with a polymeric sol, preferably under conditions of low relative pressure of the liquid constituents of the sol. The coated substrate is dried and calcined to produce the subject supported membrane. Also provided are methods of derivatizing the surface of supported inorganic membranes with metal alkoxides. The subject membranes find use in a variety of applications, such as the separation of constituents of gaseous streams, as catalysts and catalyst supports, and the like.

  10. Hybrid adsorptive membrane reactor

    NASA Technical Reports Server (NTRS)

    Tsotsis, Theodore T. (Inventor); Sahimi, Muhammad (Inventor); Fayyaz-Najafi, Babak (Inventor); Harale, Aadesh (Inventor); Park, Byoung-Gi (Inventor); Liu, Paul K. T. (Inventor)

    2011-01-01

    A hybrid adsorbent-membrane reactor in which the chemical reaction, membrane separation, and product adsorption are coupled. Also disclosed are a dual-reactor apparatus and a process using the reactor or the apparatus.

  11. Composite zeolite membranes

    DOEpatents

    Nenoff, Tina M.; Thoma, Steven G.; Ashley, Carol S.; Reed, Scott T.

    2002-01-01

    A new class of composite zeolite membranes and synthesis techniques therefor has been invented. These membranes are essentially defect-free, and exhibit large levels of transmembrane flux and of chemical and isotopic selectivity.

  12. Ionene membrane battery separator

    NASA Technical Reports Server (NTRS)

    Moacanin, J.; Tom, H. Y.

    1969-01-01

    Ionic transport characteristics of ionenes, insoluble membranes from soluble polyelectrolyte compositions, are studied for possible application in a battery separator. Effectiveness of the thin film of separator membrane essentially determines battery lifetime.

  13. Hybrid adsorptive membrane reactor

    SciTech Connect

    Tsotsis, Theodore T.; Sahimi, Muhammad; Fayyaz-Najafi, Babak; Harale, Aadesh; Park, Byoung-Gi; Liu, Paul K. T.

    2011-03-01

    A hybrid adsorbent-membrane reactor in which the chemical reaction, membrane separation, and product adsorption are coupled. Also disclosed are a dual-reactor apparatus and a process using the reactor or the apparatus.

  14. Supertubes and Superconducting Membranes

    SciTech Connect

    Cordero, Ruben; Miguel-Pilar, Zelin

    2007-02-09

    We show the equivalence between configurations that arise from string theory of type IIA, called supertubes, and superconducting membranes at the bosonic level. We find equilibrium and oscillating configurations for a tubular membrane carrying a current along its axis.

  15. Developments in the Field of Conducting and Non-conducting Polymer Based Potentiometric Membrane Sensors for Ions Over the Past Decade

    PubMed Central

    Faridbod, Farnoush; Ganjali, Mohammad Reza; Dinarvand, Rassoul; Norouzi, Parviz

    2008-01-01

    Many research studies have been conducted on the use of conjugated polymers in the construction of chemical sensors including potentiometric, conductometric and amperometric sensors or biosensors over the last decade. The induction of conductivity on conjugated polymers by treating them with suitable oxidizing agents won Heeger, MacDiarmid and Shirakawa the 2000 Nobel Prize in Chemistry. Common conjugated polymers are poly(acetylene)s, poly(pyrrole)s, poly(thiophene)s, poly(terthiophene)s, poly(aniline)s, poly(fluorine)s, poly(3-alkylthiophene)s, polytetrathiafulvalenes, poly-napthalenes, poly(p-phenylene sulfide), poly(p-phenylenevinylene)s, poly(3,4-ethylene-dioxythiophene), polyparaphenylene, polyazulene, polyparaphenylene sulfide, poly-carbazole and polydiaminonaphthalene. More than 60 sensors for inorganic cations and anions with different characteristics based on conducting polymers have been reported. There have also been reports on the application of non-conducting polymers (nCPs), i.e. PVC, in the construction of potentiometric membrane sensors for determination of more than 60 inorganic cations and anions. However, the leakage of ionophores from the membranes based on these polymers leads to relatively lower life times. In this article, we try to give an overview of Solid-Contact ISE (SCISE), Single-Piece ISE (SPISE), Conducting Polymer (CP)-Based, and also non-conducting polymer PVC-based ISEs for various ions which their difference is in the way of the polymer used with selective\\ membrane. In SCISEs and SPISEs, the plasticized PVC containing the ionophore and ionic additives govern the selectivity behavior of the electrode and the conducting polymer is responsible of ion-to-electron transducer. However, in CPISEs, the conducting polymer layer is doped with a suitable ionophore which enhances the ion selectivity of the CP while its redox response has to be suppressed. PMID:27879825

  16. Composite fuel cell membranes

    DOEpatents

    Plowman, K.R.; Rehg, T.J.; Davis, L.W.; Carl, W.P.; Cisar, A.J.; Eastland, C.S.

    1997-08-05

    A bilayer or trilayer composite ion exchange membrane is described suitable for use in a fuel cell. The composite membrane has a high equivalent weight thick layer in order to provide sufficient strength and low equivalent weight surface layers for improved electrical performance in a fuel cell. In use, the composite membrane is provided with electrode surface layers. The composite membrane can be composed of a sulfonic fluoropolymer in both core and surface layers.

  17. Composite fuel cell membranes

    DOEpatents

    Plowman, Keith R.; Rehg, Timothy J.; Davis, Larry W.; Carl, William P.; Cisar, Alan J.; Eastland, Charles S.

    1997-01-01

    A bilayer or trilayer composite ion exchange membrane suitable for use in a fuel cell. The composite membrane has a high equivalent weight thick layer in order to provide sufficient strength and low equivalent weight surface layers for improved electrical performance in a fuel cell. In use, the composite membrane is provided with electrode surface layers. The composite membrane can be composed of a sulfonic fluoropolymer in both core and surface layers.

  18. Meniscus Membranes For Separation

    DOEpatents

    Dye, Robert C.; Jorgensen, Betty; Pesiri, David R.

    2005-09-20

    Gas separation membranes, especially meniscus-shaped membranes for gas separations are disclosed together with the use of such meniscus-shaped membranes for applications such as thermal gas valves, pre-concentration of a gas stream, and selective pre-screening of a gas stream. In addition, a rapid screening system for simultaneously screening polymer materials for effectiveness in gas separation is provided.

  19. Water vapor diffusion membranes

    NASA Technical Reports Server (NTRS)

    Holland, F. F., Jr.; Smith, J. K.

    1974-01-01

    The program is reported, which was designed to define the membrane technology of the vapor diffusion water recovery process and to test this technology using commercially available or experimental membranes. One membrane was selected, on the basis of the defined technology, and was subjected to a 30-day demonstration trial.

  20. Cadmium sulfide membranes

    DOEpatents

    Spanhel, Lubomir; Anderson, Marc A.

    1991-10-22

    A method is described for the creation of novel q-effect cadmium sulfide membranes. The membranes are made by first creating a dilute cadmium sulfide colloid in aqueous suspension and then removing the water and excess salts therefrom. The cadmium sulfide membrane thus produced is luminescent at room temperature and may have application in laser fabrication.

  1. Cadmium sulfide membranes

    DOEpatents

    Spanhel, Lubomir; Anderson, Marc A.

    1992-07-07

    A method is described for the creation of novel q-effect cadmium sulfide membranes. The membranes are made by first creating a dilute cadmium sulfide colloid in aqueous suspension and then removing the water and excess salts therefrom. The cadmium sulfide membrane thus produced is luminescent at room temperature and may have application in laser fabrication.

  2. Polyphosphazene semipermeable membranes

    DOEpatents

    Allen, Charles A.; McCaffrey, Robert R.; Cummings, Daniel G.; Grey, Alan E.; Jessup, Janine S.; McAtee, Richard E.

    1988-01-01

    A semipermeable, inorganic membrane is disclosed; the membrane is prepared from a phosphazene polymer and, by the selective substitution of the constituent groups bound to the phosphorous in the polymer structure, the selective passage of fluid from a feedstream can be controlled. Resistance to high temperatures and harsh chemical environments is observed in the use of the phosphazene polymers as semipermeable membranes.

  3. Meniscus membranes for separations

    DOEpatents

    Dye, Robert C.; Jorgensen, Betty; Pesiri, David R.

    2004-01-27

    Gas separation membranes, especially meniscus-shaped membranes for gas separations are disclosed together with the use of such meniscus-shaped membranes for applications such as thermal gas valves, pre-concentration of a gas stream, and selective pre-screening of a gas stream. In addition, a rapid screening system for simultaneously screening polymer materials for effectiveness in gas separation is provided.

  4. Overview of membrane separations

    SciTech Connect

    Noble, R.D.

    1987-01-01

    The field of membrane separations is discussed. The major membrane types and applications are outlined. The outlook with respect to research activities and commercial applications is surveyed. The advantages and disadvantages of this separation process are discussed. Certain applications where membranes may save energy and improve productivity are also discussed.

  5. Experimental, Theoretical and Numerical Investigation of the Flexural Behaviour of the Composite Sandwich Panels with PVC Foam Core

    NASA Astrophysics Data System (ADS)

    Mostafa, A.; Shankar, K.; Morozov, E. V.

    2014-08-01

    This study presents the main results of an experimental, theoretical and numerical investigation on the flexural behaviour and failure mode of composite sandwich panels primarily developed for marine applications. The face sheets of the sandwich panels are made up of glass fibre reinforced polymer (GFRP), while polyvinylchloride (PVC) foam was used as core material. Four-point bending test was carried out to investigate the flexural behaviour of the sandwich panel under quasi static load. The finite element (FE) analysis taking into account the cohesive nature of the skin-core interaction as well as the geometry and materials nonlinearity was performed, while a classical beam theory was used to estimate the flexural response. Although the FE results accurately represented the initial and post yield flexural response, the theoretical one restricted to the initial response of the sandwich panel due to the linearity assumptions. Core shear failure associate with skin-core debonding close to the loading points was the dominant failure mode observed experimentally and validated numerically and theoretically.

  6. Solid state self-healing system: Effects of using PDGEBA, PVC and PVA as linear healing agents

    NASA Astrophysics Data System (ADS)

    Muhamad, Noor Nabilah; Jamil, Mohd. Suzeren Md.; Abdullah, Shahrum

    2014-09-01

    The solid state self-healing system was obtained by employing a thermosetting epoxy resin, into which a thermoplastic is dissolved. In this study, the effect of healing efficiency was investigated by using different thermoplastic polymers which are poly(bisphenol-A-co-epichlorohydrin), polyvinyl chloride and polyvinyl alcohol as healing agents. Healing was achieved by heating the fractured resins to a specific temperature i.e. above their glass transition temperature (Tg) which obtained from dynamic mechanical analysis (DMA) to mobilize the polymeric chains of the healing agent. The curing reaction in the epoxy resins were characterized by means of Fourier transform infrared spectroscopy (FTIR). Izod impact test was been performed to demonstrate self-healing of the different specimens. Under test, it was found that healable resin with PDGEBA has highest healing efficiency followed by PVC and PVA, with 63%, 35% and 18% of average percentage healing efficiencies respectively. These results are due to the different solubility parameters of the thermoset/network and thermoplastic polymer which led to the phase separation. Morphological studies prove the fracture-healing process and morphological properties of the resins.

  7. The effect of temperature on di(2-ethylhexyl) phthalate leaching from PVC infusion sets exposed to lipid emulsions.

    PubMed

    Rose, R J; Priston, M J; Rigby-Jones, A E; Sneyd, J R

    2012-05-01

    Poly vinyl chloride (PVC) infusion equipment contains substantial amounts of the plasticiser di(2-ethylhexyl) phthalate (DEHP). We determined the amount of DEHP leached from Mediplus Dual TIVA(®) Infusion sets, into lipid and non-lipid infusates. Two propofol admixtures (Diprivan(®) 1%, Propoven(®) 1%), Intralipid(®) 10% and 0.9% saline were evaluated as infusates. Solutions were infused through TIVA sets at 12 ml.h(-1) for 6 h at 24, 32 and 37 °C. In addition, TIVA sets were filled with 2 ml infusates, sealed and incubated at 24 and 37 °C for 6 h. Di(2-ethylhexyl) phthalate was detected in all lipid infusates after dynamic infusion and static contact, and in 0.9% saline after dynamic infusion at 37 °C. At 32 and 37 °C, the quantity of di(2-ethylhexyl) phthalate leaching into the lipid infusates may exceed the recommended maximum exposure amount set by the European Union for DEHP of 20-48 μg.kg(-1) day(-1) if lipid based infusates are used for sedation or intravenous feeding of infants or neonates.

  8. Tracking membrane protein association in model membranes.

    PubMed

    Reffay, Myriam; Gambin, Yann; Benabdelhak, Houssain; Phan, Gilles; Taulier, Nicolas; Ducruix, Arnaud; Hodges, Robert S; Urbach, Wladimir

    2009-01-01

    Membrane proteins are essential in the exchange processes of cells. In spite of great breakthrough in soluble proteins studies, membrane proteins structures, functions and interactions are still a challenge because of the difficulties related to their hydrophobic properties. Most of the experiments are performed with detergent-solubilized membrane proteins. However widely used micellar systems are far from the biological two-dimensions membrane. The development of new biomimetic membrane systems is fundamental to tackle this issue.We present an original approach that combines the Fluorescence Recovery After fringe Pattern Photobleaching technique and the use of a versatile sponge phase that makes it possible to extract crucial informations about interactions between membrane proteins embedded in the bilayers of a sponge phase. The clear advantage lies in the ability to adjust at will the spacing between two adjacent bilayers. When the membranes are far apart, the only possible interactions occur laterally between proteins embedded within the same bilayer, whereas when membranes get closer to each other, interactions between proteins embedded in facing membranes may occur as well.After validating our approach on the streptavidin-biotinylated peptide complex, we study the interactions between two membrane proteins, MexA and OprM, from a Pseudomonas aeruginosa efflux pump. The mode of interaction, the size of the protein complex and its potential stoichiometry are determined. In particular, we demonstrate that: MexA is effectively embedded in the bilayer; MexA and OprM do not interact laterally but can form a complex if they are embedded in opposite bilayers; the population of bound proteins is at its maximum for bilayers separated by a distance of about 200 A, which is the periplasmic thickness of Pseudomonas aeruginosa. We also show that the MexA-OprM association is enhanced when the position and orientation of the protein is restricted by the bilayers. We extract a

  9. Separation membrane development

    SciTech Connect

    Lee, M.W.

    1998-08-01

    A ceramic membrane has been developed to separate hydrogen from other gases. The method used is a sol-gel process. A thin layer of dense ceramic material is coated on a coarse ceramic filter substrate. The pore size distribution in the thin layer is controlled by a densification of the coating materials by heat treatment. The membrane has been tested by permeation measurement of the hydrogen and other gases. Selectivity of the membrane has been achieved to separate hydrogen from carbon monoxide. The permeation rate of hydrogen through the ceramic membrane was about 20 times larger than Pd-Ag membrane.

  10. Membrane separation processes

    SciTech Connect

    Rautenbach, R.; Albrecht, R.

    1989-01-01

    The success of two membrane processes, reverse osmosis and ultrafiltration, has helped make membrane processes a central technique in solving separation problems for fluid systems. This book discusses the various applications and developments in membrane technology and shows how accurate membrane processes can be designed. Starting with the local transport phenomena, the behavior of individual elements such as tube or plate membrane and the behavior of the technical unit - the module - are discussed in detail. The book goes on to demonstrate the most effective ways of arranging modules for forming an optimal plant.

  11. Asymmetric gas separation membranes

    SciTech Connect

    Malon, R. F.; Zampini, A.

    1984-12-04

    Asymmetric gas separation membranes of materials having selective permeation of at least one gas of a gaseous mixture over that of one or more remaining gases of the gaseous mixture, exhibit significantly improved permeation selectivities for the at least one gas when the asymmetric membrane is contacted on one or both surfaces with an effective amount of a Lewis acid. The improved asymmetric gas separation membranes, process for producing the improved membrane, and processes utilizing such membranes for selectively separating at least one gas from a gaseous mixture by permeation are disclosed.

  12. Asymmetric gas separation membranes

    SciTech Connect

    Malon, R. F.; Zampini, A.

    1984-09-18

    Asymmetric gas separation membranes of materials having selective permeation of at least one gas of a gaseous mixture over that of one or more remaining gases of the gaseous mixture, exhibit significantly improved permeation selectivities for the at least one gas when the asymmetric membrane is contacted on one or both surfaces with an effective amount of a Br nsted-Lowry acid. The improved asymmetric gas separation membranes, process for producing the improved membrane, and processes utilizing such membranes for selectively separating at least one gas from a gaseous mixture by permeation are disclosed.

  13. Elastic membranes in confinement

    NASA Astrophysics Data System (ADS)

    Bostwick, Joshua; Miksis, Michael; Davis, Stephen

    2014-11-01

    An elastic membrane stretched between two walls takes a shape defined by its length and the volume of fluid it encloses. Many biological structures, such as cells, mitochondria and DNA, have finer internal structure in which a membrane (or elastic member) is geometrically ``confined'' by another object. We study the shape stability of elastic membranes in a ``confining'' box and introduce repulsive van der Waals forces to prevent the membrane from intersecting the wall. We aim to define the parameter space associated with mitochondria-like deformations. We compare the confined to `unconfined' solutions and show how the structure and stability of the membrane shapes changes with the system parameters.

  14. Water Membrane Evaporator

    NASA Technical Reports Server (NTRS)

    Ungar, Eugene K.; Almlie, Jay C.

    2010-01-01

    A water membrane evaporator (WME) has been conceived and tested as an alternative to the contamination-sensitive and corrosion-prone evaporators currently used for dissipating heat from space vehicles. The WME consists mainly of the following components: An outer stainless-steel screen that provides structural support for the components mentioned next; Inside and in contact with the stainless-steel screen, a hydrophobic membrane that is permeable to water vapor; Inside and in contact with the hydrophobic membrane, a hydrophilic membrane that transports the liquid feedwater to the inner surface of the hydrophobic membrane; Inside and in contact with the hydrophilic membrane, an annular array of tubes through which flows the spacecraft coolant carrying the heat to be dissipated; and An inner exclusion tube that limits the volume of feedwater in the WME. In operation, a pressurized feedwater reservoir is connected to the volume between the exclusion tube and the coolant tubes. Feedwater fills the volume, saturates the hydrophilic membrane, and is retained by the hydrophobic membrane. The outside of the WME is exposed to space vacuum. Heat from the spacecraft coolant is conducted through the tube walls and the water-saturated hydrophilic membrane to the liquid/vapor interface at the hydrophobic membrane, causing water to evaporate to space. Makeup water flows into the hydrophilic membrane through gaps between the coolant tubes.

  15. Catalytic membranes beckon

    SciTech Connect

    Caruana, C.M.

    1994-11-01

    Chemical engineers here and abroad are finding that the marriage of catalysts and membranes holds promise for faster and more specific reactions, although commercialization of this technology is several years away. Catalytic membrane reactors (CMRs) combine a heterogeneous catalyst and a permselective membrane. Reactions performed by CMRs provide higher yields--sometimes as much as 50% higher--because of better reaction selectivity--as opposed to separation selectivity. CMRs also can work at very high temperatures, using ceramic materials that would not be possible with organic membranes. Although the use of CMRs is not widespread presently, the development of new membranes--particularly porous ceramic and zeolite membranes--will increase the potential to improve yields of many catalytic processes. The paper discusses ongoing studies, metal and advanced materials for membranes, the need for continued research, hydrogen recovery from coal-derived gases, catalytic oxidation of sulfides, CMRs for water purification, and oxidative coupling of methane.

  16. Polymers at membranes

    NASA Astrophysics Data System (ADS)

    Breidenich, Markus

    2000-11-01

    The surface of biological cells consists of a lipid membrane and a large amount of various proteins and polymers, which are embedded in the membrane or attached to it. We investigate how membranes are influenced by polymers, which are anchored to the membrane by one end. The entropic pressure exerted by the polymer induces a curvature, which bends the membrane away from the polymer. The resulting membrane shape profile is a cone in the vicinity of the anchor segment and a catenoid far away from it. The perturbative calculations are confirmed by Monte-Carlo simulations. An additional attractive interaction between polymer and membrane reduces the entropically induced curvature. In the limit of strong adsorption, the polymer is localized directly on the membrane surface and does not induce any pressure, i.e. the membrane curvature vanishes. If the polymer is not anchored directly on the membrane surface, but in a non-vanishing anchoring distance, the membrane bends towards the polymer for strong adsorption. In the last part of the thesis, we study membranes under the influence of non-anchored polymers in solution. In the limit of pure steric interactions between the membrane and free polymers, the membrane curves towards the polymers (in contrast to the case of anchored polymers). In the limit of strong adsorption the membrane bends away from the polymers. Die Oberfläche biologischer Zellen besteht aus einer Lipidmembran und einer Vielzahl von Proteinen und Polymeren, die in die Membran eingebaut sind. Die Beeinflussung der Membran durch Polymere, die mit einem Ende an der Membran verankert sind, wird im Rahmen dieser Arbeit anhand eines vereinfachten biomimetischen Systems studiert. Der entropische Druck, den das Polymer durch Stöße auf die Membran ausübt, führt dazu, dass sich die Membran vom Polymer weg krümmt. Die resultierende Membranform ist ein Kegel in der Nähe des Ankers und ein Katenoid in grossem Abstand vom Ankerpunkt. Monte Carlo-Simulationen best

  17. New molecularly-imprinted polymer for carnitine and its application as ionophore in potentiometric selective membranes.

    PubMed

    Moret, Joséphine; Moreira, Felismina T C; Almeida, Sofia A A; Sales, M Goreti F

    2014-10-01

    Carnitine (CRT) is a biological metabolite found in urine that contributes in assessingseveral disease conditions, including cancer. Novel quick screening procedures for CRT are therefore fundamental. This work proposes a novel potentiometric device where molecularly imprinted polymers (MIPs) were used as ionophores. The host-tailored sites were imprinted on a polymeric network assembled by radical polymerization of methacrylic acid (MAA) and trimethylpropane trimethacrylate (TRIM). Non-imprinted polymers (NIPs) were produced as control by removing the template from the reaction media. The selective membrane was prepared by dispersing MIP or NIP particles in plasticizer and poly(vinyl chloride), PVC, and casting this mixture over a solid contact support made of graphite. The composition of the selective membrane was investigated with regard to kind/amount of sensory material (MIP or NIP), and the need for a lipophilic additive. Overall, MIP sensors with additive exhibited the best performance, with near-Nernstian response down to ~1×10(-4)mol L(-1), at pH5, and a detection limit of ~8×10(-5)mol L(-1). Suitable selectivity was found for all membranes, assessed by the matched potential method against some of the most common species in urine (urea, sodium, creatinine, sulfate, fructose and hemoglobin). CRT selective membranes including MIP materials were applied successfully to the potentiometric determination of CRT in urine samples.

  18. Introduction to membrane lipids.

    PubMed

    Epand, Richard M

    2015-01-01

    Biological membranes are composed largely of lipids and proteins. The most common arrangement of lipids in biological membranes is as a bilayer. This arrangement spontaneously forms a barrier for the passage of polar materials. The bilayer is thin but can have a large area in the dimension perpendicular to its thickness. The physical nature of the bilayer membrane will vary according to the conditions of the environment as well as the chemical structure of the lipid constituents of the bilayer. These physical properties determine the function of the membrane together with specific structural features of the lipids that allow them to have signaling properties. The lipids of the membrane are not uniformly distributed. There is an intrinsic asymmetry between the two monolayers that constitute the bilayer. In addition, some lipids tend to be enriched in particular regions of the membrane, termed domains. There is evidence that certain domains recruit specific proteins into that domain. This has been suggested to be important for allowing interaction among different proteins involved in certain signal transduction pathways. Membrane lipids have important roles in determining the physical properties of the membrane, in modulating the activity of membrane-bound proteins and in certain cases being specific secondary messengers that can interact with specific proteins. A large variety of lipids present in biological membranes result in them possessing many functions.

  19. Potentiometric membrane sensor for the selective determination of pethidine in pharmaceutical preparations and biological fluids.

    PubMed

    Shalaby, Abdalla; El-Tohamy, Maha; El-Maamly, Magda; Aboul-Enein, Hassan Y

    2007-10-01

    The construction and general performance characteristics of a novel potentiometric PVC membrane sensor based on pethidine-phosphomolybdate as electroactive material for the determination of pethidine are described. This sensor exhibits fast, stable and near-Nernstain response 55.24 +/- 0.1, over the concentration range 1.10(-2)-1.10(-5)M for pethidine-phosphomolybdate over pH 2-7. No interferences are caused by many organic, inorganic cations, alkaloids and amino acids. The sensor proved useful for determining pethidine in pure forms, pharmaceutical injections and monitoring the content uniformity assay of ampoules. The designed sensor also show good accuracy for the determination of pethidine in biological fluids.

  20. Construction and analytical applications of plastic membrane electrode for oxymetazoline hydrochloride.

    PubMed

    Issa, Y M; Zayed, S I M

    2004-02-01

    A new oxymetazoline (OM) ion-selective PVC membrane electrode based on the ion associate of OM with phosphotungstic acid was prepared. The electrode exhibits a linear response with a mean calibration graph slope of 57.16 mV decade(-1) at 25 degrees C within the concentration range of 1.96 x 10(-5) - 1 x 10(-2) M OMCl. The change in the pH within the range of 1.0 - 9.4 did not affect the electrode performance. The standard electrode potentials were determined at different temperatures and used to calculate the isothermal coefficient of the electrode (-0.001233 V). The electrode showed a very good selectivity for OM with respect to a large number of inorganic cations and compounds. The standard addition method and potentiometric titration were applied to the determination of (OM) with RSD not exceeding 1.19%.