Finite Element Simulation and Assessment of Single-Degree-of-Freedom Prediction Methodology for Insulated Concrete Sandwich Panels Subjected to Blast Loads

DTIC Science & Technology

2011-02-01

24 Figure 21. Stress-Strain Curve of Expanded Polystyrene Insulation Foam Samples ....................25 Figure 22. Stress-Strain Curve of...Polyisocyanruate Insulation Foam Samples ............................25 Figure 23. Stress-Strain Curve of Extruded Expanded Polystyrene Insulation Foam...for modeling (Naito et al. 2009a). Insulating foams included expanded polystyrene (EPS), extruded expanded polystyrene (XPS), and polyisocyanurate

An Apparatus for Sizing Particulate Matter in Solid Rocket Motors.

DTIC Science & Technology

1984-06-01

accurately measured. A curve for sizing polydispersions was presented which was used by Cramer and Hansen [Refs. 2, 12]. Two phase flow losses are often...Concentration...... 54 18. 5 Micron Polystyrene, Curve Fit .......... ... 55 19. 5 Micron Polystyrene, Two Angle Method ........ .56.... 20. 10 Micron...Polystyrene, Curve Fit .. ........ 57....[57 21. 10 Micron Polystyrene, Two Angle Method .. ....... .58 . . .6_ *22. 20J Mizron P3iystvrene Cu. .Fi

Small angle x-ray scattering study on the conformation of polystyrene in toluene during adding anti-solvent CO2

NASA Astrophysics Data System (ADS)

Liu, Yi; Chen, Dong-Feng; Wang, Hong-Li; Chen, Na; Li, Dan; Han, Bu-Xing; Rong, Li-Xia; Zhao, Hui; Wang, Jun; Dong, Bao-Zhong

2002-10-01

The conformation of polystyrene in the anti-solvent process of supercritical fluids (compressed CO2 + polystyrene + toluene) has been studied by small angle x-ray scattering with synchrotron radiation as an x-ray source. Coil-to-globule transformation of the polystyrene chain was observed with the increase of the anti-solvent CO2 pressure; i.e. polystyrene coiled at a pressure lower than the cloud point pressure (Pc) and turned into a globule with a uniform density at pressures higher than Pc. Fractal behaviour was also found in the chain contraction and the mass fractal dimension increased with increasing CO2 pressure.

Structural Composite Construction Materials Manufactured from Municipal Solid Waste

DTIC Science & Technology

1994-04-20

in Table 1. Candidate matrix materials included polystyrene (PS) or expanded polystyrene (EPS), high density polyethylene (HDPE), and polyethylene...companies make a variety of expanded polystyrene insulation panels that arc used in insulation and roofing systems.46 Thermoplastics are seeing

Considerations for the Use of Exterior Insulation & Finish Systems (EIFS) on U.S. Army Facilities

DTIC Science & Technology

1991-11-01

Typical kinds of insulation used in EIFS include molded expanded polystyrene (MEPS), extruded expanded polystyrene (XEPS), semi-rigid fiberglass, and...Extruded expanded polystyrene insulation, see XEPS 85 Finish coat 12-17, 20, 22-24, 26 degradation 32, 61, 68, 71, 78 Impact damage 28, 56, 83 resistance 15...lath 12, 15, 16, 20, 25, 74 Mildew 14, 78 Molded expanded polystyrene insulation, see MEPS Notched trowel application 19, 74 Portland cement 13, 15-17

Polystyrene microplastics induce microbiota dysbiosis and inflammation in the gut of adult zebrafish.

PubMed

Jin, Yuanxiang; Xia, Jizhou; Pan, Zihong; Yang, Jiajing; Wang, Wenchao; Fu, Zhengwei

2018-04-01

Microplastic (MP) are environmental pollutants and have the potential to cause varying degrees of aquatic toxicity. In this study, the effects on gut microbiota of adult male zebrafish exposed for 14 days to 100 and 1000 μg/L of two sizes of polystyrene MP were evaluated. Both 0.5 and 50 μm-diameter spherical polystyrene MP increased the volume of mucus in the gut at a concentration of 1000 μg/L (about 1.456 × 10 10 particles/L for 0.5 μm and 1.456 × 10 4 particles/L for 50 μm). At the phylum level, the abundance of Bacteroidetes and Proteobacteria decreased significantly and the abundance of Firmicutes increased significantly in the gut after 14-day exposure to 1000 μg/L of both sizes of polystyrene MP. In addition, high throughput sequencing of the 16S rRNA gene V3-V4 region revealed a significant change in the richness and diversity of microbiota in the gut of polystyrene MP-exposed zebrafish. A more in depth analysis, at the genus level, revealed that a total of 29 gut microbes identified by operational taxonomic unit (OTU) analysis were significantly changed in both 0.5 and 50 μm-diameter polystyrene MP-treated groups. Moreover, it was observed that 0.5 μm polystyrene MP not only increased mRNA levels of IL1α, IL1β and IFN but also their protein levels in the gut, indicating that inflammation occurred after polystyrene MP exposure. Our findings suggest that polystyrene MP could induce microbiota dysbiosis and inflammation in the gut of adult zebrafish. Copyright © 2017 Elsevier Ltd. All rights reserved.

Solvent effect on polystyrene surface roughness on top of QCM sensor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sakti, Setyawan P., E-mail: sakti@ub.ac.id; Rahmawati, Eka; Robiandi, Fadli

2016-03-11

Quartz Crystal Microbalance (QCM) has been used as a basis for many chemical sensors and biosensor. Its sensitivity to mass change which can detect a mass change on its surface down to sub ng/cm2 is one of its interesting aspects. Another interesting feature is its ability to work in liquid environment. However, there are many aspects which influence QCM sensor properties in contact with liquid. One of the aspects is surface roughness of the matrix layer where on top of it a biological sensitive layer will be immobilized. One of matrix layers in the immobilizing biological sensitive layer was polystyrene.more » Polystyrene was coated on the QCM sensor by using the spin coating method. During the coating process, polystyrene was solved using non-polar solvent. It is known that the physical and chemical properties of the solvent affect a transition process from soluble polymer becoming rigid polymer layer. In this work, we show that polystyrene solved in chloroform has a higher surface roughness compare to one solved in toluene, xylene, or tetrahydrofuran. Surface roughness of the polystyrene coating were measured using a non-contact profilometer. However, we also found that there is no difference on the electrical impedance of the QCM sensor coated with polystyrene resulted from differing solvent when the sensor was in contact with air and water. Thus, all of the mentioned solvent can be used to solve the polystyrene as a coating material for QCM sensor without affecting the electrical performance of the sensor, but the choice of the solution can be used as a simple method to control the difference roughness of the polystyrene coating.« less

Solvent effect on polystyrene surface roughness on top of QCM sensor

NASA Astrophysics Data System (ADS)

Sakti, Setyawan P.; Rahmawati, Eka; Robiandi, Fadli

2016-03-01

Quartz Crystal Microbalance (QCM) has been used as a basis for many chemical sensors and biosensor. Its sensitivity to mass change which can detect a mass change on its surface down to sub ng/cm2 is one of its interesting aspects. Another interesting feature is its ability to work in liquid environment. However, there are many aspects which influence QCM sensor properties in contact with liquid. One of the aspects is surface roughness of the matrix layer where on top of it a biological sensitive layer will be immobilized. One of matrix layers in the immobilizing biological sensitive layer was polystyrene. Polystyrene was coated on the QCM sensor by using the spin coating method. During the coating process, polystyrene was solved using non-polar solvent. It is known that the physical and chemical properties of the solvent affect a transition process from soluble polymer becoming rigid polymer layer. In this work, we show that polystyrene solved in chloroform has a higher surface roughness compare to one solved in toluene, xylene, or tetrahydrofuran. Surface roughness of the polystyrene coating were measured using a non-contact profilometer. However, we also found that there is no difference on the electrical impedance of the QCM sensor coated with polystyrene resulted from differing solvent when the sensor was in contact with air and water. Thus, all of the mentioned solvent can be used to solve the polystyrene as a coating material for QCM sensor without affecting the electrical performance of the sensor, but the choice of the solution can be used as a simple method to control the difference roughness of the polystyrene coating.

Serotyping of Actinobacillus pleuropneumoniae serotype 5 strains using a monoclonal-based polystyrene agglutination test.

PubMed Central

Dubreuil, J D; Letellier, A; Stenbaek, E; Gottschalk, M

1996-01-01

A polystyrene agglutination test has been developed for serotyping Actinobacillus pleuropneumoniae serotype 5a and 5b strains. Protein A-coated polystyrene microparticles were sensitized with a murine monoclonal antibody recognizing an epitope on serotype 5 LPS-O chain as shown by SDS-PAGE and Western blotting. A total of 205 A. pleuropneumoniae, strains including all 12 serotype reference strains and 13 strains representing 8 common bacterial species associated with swine or related to A. pleuropneumoniae, were tested by mixing 25 microL of polystyrene reagent with the same volume of a dense suspension of bacterial cells grown for 18 h. All A. pleuropneumoniae strains had been previously serotyped using standard procedures. The polystyrene agglutination test was rapid (less than 3 min) and easy to perform. Overall a very good correlation (97.3%) with the standard techniques was found. The sensitized polystyrene particles were stable for at least 6 mo. Images Figure 1. PMID:8825998

Characterisation of recycled acrylonitrile-butadiene-styrene and high-impact polystyrene from waste computer equipment in Brazil.

PubMed

Hirayama, Denise; Saron, Clodoaldo

2015-06-01

Polymeric materials constitute a considerable fraction of waste computer equipment and polymers acrylonitrile-butadiene-styrene and high-impact polystyrene are the main thermoplastic polymeric components found in waste computer equipment. Identification, separation and characterisation of additives present in acrylonitrile-butadiene-styrene and high-impact polystyrene are fundamental procedures to mechanical recycling of these polymers. The aim of this study was to evaluate the methods for identification of acrylonitrile-butadiene-styrene and high-impact polystyrene from waste computer equipment in Brazil, as well as their potential for mechanical recycling. The imprecise utilisation of symbols for identification of the polymers and the presence of additives containing toxic elements in determinate computer devices are some of the difficulties found for recycling of acrylonitrile-butadiene-styrene and high-impact polystyrene from waste computer equipment. However, the considerable performance of mechanical properties of the recycled acrylonitrile-butadiene-styrene and high-impact polystyrene when compared with the virgin materials confirms the potential for mechanical recycling of these polymers. © The Author(s) 2015.

Field efficacy of expanded polystyrene and shredded waste polystyrene beads for mosquito control in artificial pools and field trials, Islamic Republic of Iran.

PubMed

Soltani, A; Vatandoost, H; Jabbari, H; Mesdaghinia, A R; Mahvi, A H; Younesian, M; Hanafi-Bojd, A A; Bozorgzadeh, S

2012-10-01

Concerns about traditional chemical pesticides has led to increasing research into novel mosquito control methods. This study compared the effectiveness of 2 different types of polystyrene beads for control of mosquito larvae in south-east Islamic Republic of Iran. Simulated field trials were done in artificial pools and field trials were carried out in 2 villages in an indigenous malaria area using WHO-recommended methods. Application of expanded polystyrene beads or shredded, waste polystyrene chips to pool surfaces produced a significant difference between pre-treatment and post-treatment density of mosquitoes (86% and 78% reduction respectively 2 weeks after treatment). There was no significant difference between the efficacy of the 2 types of material. The use of polystyrene beads as a component of integrated vector management with other supportive measures could assist in the control of mosquito-borne diseases in the Islamic Republic of Iran and neighbouring countries.

Optimizing biomass blends for manufacturing molded packaging materials using mycelium

USDA-ARS?s Scientific Manuscript database

Polystyrene is one of the most widely used plastics and is commonly produced in three forms: 1) Extruded polystyrene – disposable utensils, CD/DVD cases, yogurt containers, smoke alarm housing, etc.; 2) Expanded polystyrene foam – molded packaging materials and packaging "peanuts"; 3) Extruded polys...

40 CFR 63.1317 - PET and polystyrene affected sources-monitoring provisions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 12 2013-07-01 2013-07-01 false PET and polystyrene affected sources-monitoring provisions. 63.1317 Section 63.1317 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... and Resins § 63.1317 PET and polystyrene affected sources—monitoring provisions. Continuous process...

40 CFR 63.1317 - PET and polystyrene affected sources-monitoring provisions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 12 2014-07-01 2014-07-01 false PET and polystyrene affected sources-monitoring provisions. 63.1317 Section 63.1317 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... and Resins § 63.1317 PET and polystyrene affected sources—monitoring provisions. Continuous process...

40 CFR 63.1319 - PET and polystyrene affected sources-recordkeeping provisions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 12 2013-07-01 2013-07-01 false PET and polystyrene affected sources... and Resins § 63.1319 PET and polystyrene affected sources—recordkeeping provisions. (a) Except as....113. (b) Records demonstrating compliance with the applicability determination procedure for PET...

7 CFR 3201.53 - Expanded polystyrene (EPS) foam recycling products.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 15 2014-01-01 2014-01-01 false Expanded polystyrene (EPS) foam recycling products... FOR FEDERAL PROCUREMENT Designated Items § 3201.53 Expanded polystyrene (EPS) foam recycling products... with this part, will give a procurement preference for qualifying biobased EPS foam recycling products...

7 CFR 3201.53 - Expanded polystyrene (EPS) foam recycling products.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 15 2012-01-01 2012-01-01 false Expanded polystyrene (EPS) foam recycling products... FOR FEDERAL PROCUREMENT Designated Items § 3201.53 Expanded polystyrene (EPS) foam recycling products... with this part, will give a procurement preference for qualifying biobased EPS foam recycling products...

7 CFR 2902.53 - Expanded polystyrene (EPS) foam recycling products.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 15 2011-01-01 2011-01-01 false Expanded polystyrene (EPS) foam recycling products... FEDERAL PROCUREMENT Designated Items § 2902.53 Expanded polystyrene (EPS) foam recycling products. (a..., will give a procurement preference for qualifying biobased EPS foam recycling products. By that date...

7 CFR 3201.53 - Expanded polystyrene (EPS) foam recycling products.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 15 2013-01-01 2013-01-01 false Expanded polystyrene (EPS) foam recycling products... FOR FEDERAL PROCUREMENT Designated Items § 3201.53 Expanded polystyrene (EPS) foam recycling products... with this part, will give a procurement preference for qualifying biobased EPS foam recycling products...

Wetting behavior on hexagonally close-packed polystyrene bead arrays with different topographies.

PubMed

Park, Yi-Seul; Yoon, Seo Young; Lee, Jin Seok

2016-01-21

Herein, we investigated the wetting behavior of hexagonally close-packed polystyrene bead arrays with different bead diameters and surface flatness. The contact angle was found to be influenced by the surface roughness as well as the contact area of the polystyrene bead array with a water droplet.

Packing Products: Polystyrene vs. Cornstarch

ERIC Educational Resources Information Center

Starr, Suzanne

2009-01-01

Packing materials such as polystyrene take thousands of years to decompose, whereas packing peanuts made from cornstarch, which some companies are now using, can serve the same purpose, but dissolve in water. The author illustrates this point to her class one rainy day using the sculptures students made from polystyrene and with the cornstarch…

40 CFR 63.1317 - PET and polystyrene affected sources-monitoring provisions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 12 2012-07-01 2011-07-01 true PET and polystyrene affected sources-monitoring provisions. 63.1317 Section 63.1317 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... § 63.1317 PET and polystyrene affected sources—monitoring provisions. Continuous process vents using a...

40 CFR 63.1320 - PET and polystyrene affected sources-reporting provisions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 12 2012-07-01 2011-07-01 true PET and polystyrene affected sources... § 63.1320 PET and polystyrene affected sources—reporting provisions. (a) Except as specified in... PET Affected Sources Using a Dimethyl Terephthalate Process. Owners or operators complying with § 63...

40 CFR 63.1319 - PET and polystyrene affected sources-recordkeeping provisions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 11 2011-07-01 2011-07-01 false PET and polystyrene affected sources... § 63.1319 PET and polystyrene affected sources—recordkeeping provisions. (a) Except as specified in... demonstrating compliance with the applicability determination procedure for PET affected sources using a...

40 CFR 63.1320 - PET and polystyrene affected sources-reporting provisions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 12 2013-07-01 2013-07-01 false PET and polystyrene affected sources... and Resins § 63.1320 PET and polystyrene affected sources—reporting provisions. (a) Except as...) Reporting for PET Affected Sources Using a Dimethyl Terephthalate Process. Owners or operators complying...

40 CFR 63.1320 - PET and polystyrene affected sources-reporting provisions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 11 2010-07-01 2010-07-01 true PET and polystyrene affected sources... § 63.1320 PET and polystyrene affected sources—reporting provisions. (a) Except as specified in... PET Affected Sources Using a Dimethyl Terephthalate Process. Owners or operators complying with § 63...

40 CFR 63.1317 - PET and polystyrene affected sources-monitoring provisions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 11 2011-07-01 2011-07-01 false PET and polystyrene affected sources-monitoring provisions. 63.1317 Section 63.1317 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... § 63.1317 PET and polystyrene affected sources—monitoring provisions. Continuous process vents using a...

40 CFR 63.1320 - PET and polystyrene affected sources-reporting provisions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 11 2011-07-01 2011-07-01 false PET and polystyrene affected sources... § 63.1320 PET and polystyrene affected sources—reporting provisions. (a) Except as specified in... PET Affected Sources Using a Dimethyl Terephthalate Process. Owners or operators complying with § 63...

40 CFR 63.1317 - PET and polystyrene affected sources-monitoring provisions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 11 2010-07-01 2010-07-01 true PET and polystyrene affected sources-monitoring provisions. 63.1317 Section 63.1317 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... § 63.1317 PET and polystyrene affected sources—monitoring provisions. Continuous process vents using a...

Sequential pyrolysis of plastic to recover polystyrene HCL and terephthalic acid

DOEpatents

Evans, Robert J.; Chum, Helena L.

1995-01-01

A process of pyrolyzing plastic waste feed streams containing polyvinyl chloride, polyethylene terephthalate, polystyrene and polyethylene to recover polystyrene HCl and terephthalic acid comprising: heating the plastic waste feed stream to a first temperature; adding an acid or base catalyst on an oxide or carbonate support; heating the plastic waste feed stream to pyrolyze polyethylene terephthalate and polyvinyl chloride; separating terephthalic acid or HCl; heating to a second temperature to pyrolyze polystyrene; separating styrene; heating the waste feed stream to a third temperature to pyrolyze polyethylene; and separating hydrocarbons.

Coupling of carboxylic groups onto the surface of polystyrene parts during fused filament fabrication

NASA Astrophysics Data System (ADS)

Nagel, Jürgen; Zimmermann, Philipp; Schubert, Oliver; Simon, Frank; Schlenstedt, Kornelia

2017-11-01

A method for the fabrication of polystyrene parts, modified with carboxylic groups during Fused Filament Fabrication (FFF), is being introduced. This method is based on the application of a thin layer of a reactive polymer carrying carboxylic groups on a substrate surface. A polystyrene film is printed on top of this layer. During contact between the hot melt and the reactive layer, a Friedel-Crafts type acylation using a green catalyst takes place, which attaches the reactive polymer to the polystyrene surface. The modified surface is homogeneous, hydrophilic and able to bind copper ions. The method could be used to fabricate unique parts of polystyrene with tailored surface functionalisation. It could be applied for laboratory use, e.g. for the manufacture of lab-on-a-chip devices.

Determining the unique refractive index properties of solid polystyrene aerosol using broadband Mie scattering from optically trapped beads.

PubMed

Jones, Stephanie H; King, Martin D; Ward, Andrew D

2013-12-21

A method is described to measure the refractive index dispersion with wavelength of optically trapped solid particles in air. Knowledge of the refraction properties of solid particles is critical for the study of aerosol; both in the laboratory and in the atmosphere for climate studies. Single micron-sized polystyrene beads were optically trapped in air using a vertically aligned counter-propagating configuration of focussed laser beams. Each bead was illuminated using white light from a broadband light emitting diode (LED) and elastic scattering within the bead was collected onto a spectrograph. The resulting Mie spectra were analysed to accurately determine polystyrene bead radii to ±0.4 nm and values of the refractive index to ±0.0005 over a wavelength range of 480-700 nm. We demonstrate that optical trapping combined with elastic scattering can be used to both accurately size polystyrene beads suspended in air and determine their wavelength dependent refractive index. The refractive index dispersions are in close agreement with reported values for polystyrene beads in aqueous dispersion. Our results also demonstrate a variation in the refractive index of polystyrene, from bead to bead, in a commercial sample. The measured variation highlights that care must be taken when using polystyrene beads as a calibration aerosol.

Biodegradation of polystyrene-graft-starch copolymers in three different types of soil.

PubMed

Nikolic, Vladimir; Velickovic, Sava; Popovic, Aleksandar

2014-01-01

Materials based on polystyrene and starch copolymers are used in food packaging, water pollution treatment, and textile industry, and their biodegradability is a desired characteristic. In order to examine the degradation patterns of modified, biodegradable derivates of polystyrene, which may keep its excellent technical features but be more environmentally friendly at the same time, polystyrene-graft-starch biomaterials obtained by emulsion polymerization in the presence of new type of initiator/activator pair (potassium persulfate/different amines) were subjected to 6-month biodegradation by burial method in three different types of commercially available soils: soil rich in humus and soil for cactus and orchid growing. Biodegradation was monitored by mass decrease, and the highest degradation rate was achieved in soil for cactus growing (81.30%). Statistical analysis proved that microorganisms in different soil samples have different ability of biodegradation, and there is a significant negative correlation between the share of polystyrene in copolymer and degree of biodegradation. Grafting of polystyrene on starch on one hand prevents complete degradation of starch that is present (with maximal percentage of degraded starch ranging from 55 to 93%), while on the other hand there is an upper limit of share of polystyrene in the copolymer (ranging from 37 to 77%) that is preventing biodegradation of degradable part of copolymers.

Effect of salivary secretory IgA on the adhesion of Candida albicans to polystyrene.

PubMed

San Millán, R; Elguezabal, N; Regúlez, P; Moragues, M D; Quindós, G; Pontón, J

2000-09-01

Attachment of Candida albicans to plastic materials of dental prostheses or to salivary macromolecules adsorbed on their surface is believed to be a critical event in the development of denture stomatitis. In an earlier study, it was shown that adhesion of C. albicans to polystyrene, a model system to study the adhesion of C. albicans to plastic materials, can be partially inhibited with an mAb directed against cell wall polysaccharides of C. albicans. In the present study, the role of whole saliva in the adhesion of C. albicans to polystyrene has been investigated, and three mAbs directed against epitopes of cell wall mannoproteins have been used to mimic the inhibitory effect observed with salivary secretory IgA (sIgA) on the adhesion of C. albicans to polystyrene. In the absence of whole saliva, adherence of C. albicans 3153 increased with germination. However, the presence of whole saliva enhanced the adhesion to polystyrene of C. albicans 3153 yeast cells but decreased the adhesion of germinated cells. The enhancement of adhesion of yeast cells to polystyrene mediated by saliva was confirmed with an agerminative mutant of C. albicans 3153. The inhibition of the adhesion of C. albicans 3153 germ tubes to polystyrene was due to the salivary sIgA since sIgA-depleted saliva enhanced the adhesion of C. albicans 3153 to polystyrene. The inhibitory effect mediated by sIgA was not related to the inhibition of germination but to the blockage of adhesins expressed on the cell wall surface of the germ tubes. The three mAbs studied reduced the adhesion of C. albicans 3153 to polystyrene at levels equivalent to those for purified sIgA. The highest reduction in the adhesion was obtained with the IgA mAb N3B. The best results were obtained when the three mAbs were combined. The results suggest that whole saliva plays a different role in the adhesion of C. albicans to polystyrene depending on the morphological phase of C. albicans. These results may give new insights into the conflicting role of saliva in the adhesion of C. albicans to plastic materials of dental prostheses.

Evaluation of Biomass Residual Substrate Blends for Eco-Friendly Packaging and Insulation Sheets/Panels

USDA-ARS?s Scientific Manuscript database

Polystyrene is one of the most widely used plastics and is commonly produced in three forms: 1) Extruded polystyrene – disposable utensils, CD/DVD cases, yogurt containers, smoke alarm housing, etc.; 2) Expanded polystyrene foam – molded packaging materials and packaging "peanuts"; and 3) Extruded p...

Optimization of biomass blends in the manufacture of molded packaging materials produced using fungal mycelium

USDA-ARS?s Scientific Manuscript database

Polystyrene is one of the most widely used plastics and is commonly produced in three forms: 1) Extruded polystyrene – disposable utensils, CD/DVD cases, yogurt containers, smoke alarm housing, etc.; 2) Expanded polystyrene foam – molded packaging materials and packaging "peanuts"; 3) Extruded polys...

40 CFR 63.1316 - PET and polystyrene affected sources-emissions control provisions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 12 2012-07-01 2011-07-01 true PET and polystyrene affected sources... and Resins § 63.1316 PET and polystyrene affected sources—emissions control provisions. (a) The owner or operator of an affected source producing PET using a continuous process shall comply with...

40 CFR 63.1316 - PET and polystyrene affected sources-emissions control provisions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 12 2013-07-01 2013-07-01 false PET and polystyrene affected sources... Polymers and Resins § 63.1316 PET and polystyrene affected sources—emissions control provisions. (a) The owner or operator of an affected source producing PET using a continuous process shall comply with...

40 CFR 63.1316 - PET and polystyrene affected sources-emissions control provisions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 12 2014-07-01 2014-07-01 false PET and polystyrene affected sources... Polymers and Resins § 63.1316 PET and polystyrene affected sources—emissions control provisions. (a) The owner or operator of an affected source producing PET using a continuous process shall comply with...

Trichomonas vaginalis clinical isolates: cytoadherence and adherence to polystyrene, intrauterine device, and vaginal ring.

PubMed

Dos Santos, Odelta; Rigo, Graziela Vargas; Macedo, Alexandre José; Tasca, Tiana

2017-12-01

The parasitism by Trichomonas vaginalis is complex and in part is mediated by cytoadherence accomplished via five surface proteins named adhesins and a glycoconjugate called lipophosphoglycan (TvLPG). In this study, we evaluated the ability of T. vaginalis isolates to adhere to cells, plastic (polystyrene microplates), intrauterine device (IUD), and vaginal ring. Of 32 T. vaginalis isolates, 4 (12.5%) were strong adherent. The T. vaginalis isolates TV-LACM6 and TV-LACM14 (strong polystyrene-adherent) were also able to adhere to IUD and vaginal ring. Following chemical treatments, results demonstrated that the T. vaginalis components, lipophosphoglycan, cytoskeletal proteins, and surface molecules, were involved in both adherence to polystyrene and cytoadherence. The gene expression level from four adhesion proteins was highest in trophozoites adhered to cells than trophozoites adhered to the abiotic surface (polystyrene microplate). Our data indicate the major involvement of TvLPG in adherence to polystyrene, and that adhesins are important for cytoadherence. Furthermore, to our knowledge, this is the first report showing the T. vaginalis adherence to contraceptive devices, reaffirming its importance as pathogen among women in reproductive age.

Adsorption of Nanoplastics on Algal Photosynthesis

NASA Astrophysics Data System (ADS)

Turner, James; Bhattacharya, Priyanka; Lin, Sijie; Ke, Pu Chun

2010-03-01

The rapid accumulation of disposed plastics in the environment, especially in the Pacific Ocean, has become a global concern in recent years. Photo, chemical and physical degradations constantly fragment these plastics into a wide array of macroscopic to microscopic particles. As a result, marine organisms such as algae may be exposed to plastic particles through ingestion, adsorption and other forms of uptake. Such interactions, currently little understood, could potentially impact on the health state of the entire food chain. Here we report on polystyrene-algae interaction and its impact on algal photosynthesis. We first investigated the adsorption of polystyrene beads (20 nm) on a cellulose film coated on a 96-well plate. We derived a supralinear increase of the adsorption with the beads concentration for both positively and negatively charged polystyrene beads, with a saturation observed for the negatively charged polystyrene beads of concentration above 1.6 mg/mL. Using a bicarbonate indicator we discovered decreased carbon dioxide depletion due to polystyrene-algae binding. Since polystyrene beads also mediated algae aggregation, nanoplastics may alternatively be harnessed for waste water treatment.

Photostability and Performance of Polystyrene Films Containing 1,2,4-Triazole-3-thiol Ring System Schiff Bases.

PubMed

Ali, Gassan Q; El-Hiti, Gamal A; Tomi, Ivan Hameed R; Haddad, Raghad; Al-Qaisi, Alaa J; Yousif, Emad

2016-12-09

Series of 4-(4-substituted benzylideneamino)-5-(3,4,5-trimethoxyphenyl)-4 H -1,2,4-triazole-3-thiols were synthesized and their structures were confirmed. The synthesized Schiff bases were used as photostabilizers for polystyrene against photodegradation. Polystyrene polymeric films containing synthesized Schiff bases (0.5% by weight) were irradiated (λ max = 365 nm and light intensity = 6.43 × 10 -9 ein·dm -3 ·s -1 ) at room temperature. The photostabilization effect of 1,2,4-triazole-3-thiols Schiff bases was determined using various methods. All the additives used enhanced the photostability of polystyrene films against irradiation compared with the result obtained in the absence of Schiff base. The Schiff bases can act as photostabilizers for polystyrene through the direct absorption of UV radiation and/or radical scavengers.

Precast/Prestressed Concrete Experiments Performance on Non-Load Bearing Sandwich Wall Panels

DTIC Science & Technology

2011-01-01

expanded polystyrene (EPS), extruded expanded polystyrene (XPS...34 Ø Strands @ 14.9 kips 3/8" Ø Strands @ 14.9 kips 9" #3@18" XEPS Insulation Extruded Expanded Polystyrene 4" (Metal C-Pins) Metal C-Pins 1’-8" 3" 3...34 3" 8" 1’-4" 8" 2’-8" 11 2 " 6" 11 2 " 3/8" Ø Strands @ 14.9 kips 3/8" Ø Strands @ 14.9 kips 9" #3@18" XEPS Insulation Extruded Expanded Polystyrene

Sequential pyrolysis of plastic to recover polystyrene, HCl and terephthalic acid

DOEpatents

Evans, R.J.; Chum, H.L.

1995-11-07

A process is described for pyrolyzing plastic waste feed streams containing polyvinyl chloride, polyethylene terephthalate, polystyrene and polyethylene to recover polystyrene, HCl and terephthalic acid comprising: heating the plastic waste feed stream to a first temperature; adding an acid or base catalyst on an oxide or carbonate support; heating the plastic waste feed stream to pyrolyze polyethylene terephthalate and polyvinyl chloride; separating terephthalic acid or HCl; heating to a second temperature to pyrolyze polystyrene; separating styrene; heating the waste feed stream to a third temperature to pyrolyze polyethylene; and separating hydrocarbons. 83 figs.

Microscale synthesis and characterization of polystyrene: NSF-POLYED scholars project

NASA Technical Reports Server (NTRS)

Quaal, Karen S.; Wu, Chang-Ning

1994-01-01

Polystyrene is a familiar polymer with many commercial uses. Its applications range from the clear, high index of refraction, brittle plastic used to form audio cassette and CD cases to the foamed material used in insulated drink cups and packaging material. Polystyrene constitutes 11 percent of the plastics used in packaging with only High Density Polyethylene (HDPE) and Low Density Polyethylene (LDPE) contributing a larger share: so much polystyrene is used today, it is one of six common plastics that manufacturers have assigned an identification code. The code helps recycling efforts. Polystyrene's code is (PS code 6). During the summer and fall of 1992 several new polymeric experiments were developed by the NSF POLYED Scholars for introduction into the chemistry core curriculum. In this presentation, one such project will be discussed. This laboratory project is recommended for a first or second year laboratory course allowing the introduction of polymeric science to undergraduates at the earliest opportunity. The reliability of the experiments which make up this project and the recognition factor of polystyrene, a material we come in contact with everyday, makes the synthesis and characterization of polystyrene a good choice for the introduction of polymerization to undergraduates. This laboratory project appeals to the varied interests of students enrolled in the typical first year chemistry course and becomes an ideal way to introduce polymers to a wide variety of science and engineering students.

Ductility of polystyrene waste panel

NASA Astrophysics Data System (ADS)

Sulistyorini, Dewi; Yasin, Iskandar

2018-03-01

Polystyrene waste panel is one of alternative materials that uses polystyrene waste. This experiment is to utilize the polystyrene waste as a non structural panel to be evaluated the ductility. The specimen consisted of cement 250 kg/m3, polystyrene waste was as aggregate, water cement ratio was 0.4 and wire mesh diameter was 0.6 mm with the grid 6 mm × 6 mm placed on the top and bottom of the panels. The polystyrene panels were compressed at 2 MPa. Six specimens had dimension 80 cm length, 30 cm width and the thickness planned were two varieties, they were 0.5 cm and 1 cm. Flexural testing is used to examine load and deflection to measure the ductility. The load and the deflection showed that the maximum load for the specimen with 0.5 cm thickness is 0.4, 0.56 and 0.37. And for 1 cm thickness is 0.4, 0.36, 0.64. It shows that the thickness variation does not give effect on the maximum load. Result showed the average of Displacement Ductility Index of polystyrene waste panels with 0.5 cm thickness was 1.692 and for 1 cm thickness, the average was 4.043. So the average of the panel with 0.5 cm thickness planned is under 1.99 and the panel with 1 cm thickness planned is upper 3, therefore, it is considered imperative for adequate ductility.

40 CFR 63.1318 - PET and polystyrene affected sources-testing and compliance demonstration provisions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 11 2011-07-01 2011-07-01 false PET and polystyrene affected sources...: Group IV Polymers and Resins § 63.1318 PET and polystyrene affected sources—testing and compliance... not apply and owners or operators are not required to comply with § 63.113. (b) PET affected sources...

40 CFR 63.1318 - PET and polystyrene affected sources-testing and compliance demonstration provisions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 12 2012-07-01 2011-07-01 true PET and polystyrene affected sources...: Group IV Polymers and Resins § 63.1318 PET and polystyrene affected sources—testing and compliance... not apply and owners or operators are not required to comply with § 63.113. (b) PET affected sources...

40 CFR 63.1318 - PET and polystyrene affected sources-testing and compliance demonstration provisions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 11 2010-07-01 2010-07-01 true PET and polystyrene affected sources...: Group IV Polymers and Resins § 63.1318 PET and polystyrene affected sources—testing and compliance... not apply and owners or operators are not required to comply with § 63.113. (b) PET affected sources...

The properties of the wood-polystyrene interphase determined by inverse gas chromatography

Treesearch

John Simonsen; Zhenqiu Hong; Timothy G. Rials

1997-01-01

The properties of the interphase in wood-polymer composites are important determinants of the properties of the final composite. This study used inverse gas chromatography (IGC) to measure interphasal properties of composites of polystyrene and two types of wood fiber fillers and an inoranic substrate (CW) with varying amounts of surface coverage of polystyrene. Glass...

Magnetic graphene oxide-polystyrene and magnetic activated carbon-polystyrene nanocomposites as sorbents for bisphenol A.

NASA Astrophysics Data System (ADS)

Rekos, Kyriazis; Kampouraki, Zoi Christina; Samanidou, Victoria; Deliyanni, Eleni

2016-04-01

Magnetic graphene oxide-polystyrene and magnetic activated carbon-polystyrene nanocomposites as sorbents for bisphenol A. Kyriazis Rekos1, Zoi Christina Kampouraki1, Victoria Samanidou2, Eleni Deliyanni1 1 Laboratory of General and Inorganic Chemical Technology, Department of Chemistry, Aristotle University of Thessaloniki, GR-541 24 Thessaloniki, Greece 2 Laboratory of Analytical Chemistry, Department of Chemistry, Aristotle University of Thessaloniki, GR-541 24 Thessaloniki, Greece The aim of this work was to prepare and characterize novel composites of magnetic activated carbon or magnetic graphene oxide with polystyrene (GO/PSm), through one step simple and effective route. Μagnetite nanoparticles, prepared in the laboratory, were dispersed in the presence of activated carbon (C) or graphene oxide (GO) in a polystyrene (PS) solution in dimethylformamide, at elevated temperature, for the fabrication of the magnetite-Carbon-PS (C-PSm) and magnetite- Graphene Oxide-PS (GO-PSm) hybrid-nanoparticles. For comparison, C-PS and GO-PS composites were also prepared in the same route. The nanocomposites were tested for their sorption ability for an endocrine disruptor, bisphenol A. The effect of solution pH, initial concentration, contact time and temperature were examined. The magnetic graphite oxide-polystyrene presented higher adsorption capacity (100 mg/g) than the non magnetic composites (70 mg/g), as well as than initial graphite oxide (20 mg/g). FTIR, XRD, BET, TGA, VSM and SEM were performed in order to investigate the role of the PS on the better adsorption performance of the mGO-PS nanocomposites. The characterization with these techniques revealed the possible interactions of the surface functional groups of activated carbon and/or graphite oxide with polystyrene that resulted in the better performance of the magnetic nanocomposites for bisphenol A adsorption.

Randomized Clinical Trial of Sodium Polystyrene Sulfonate for the Treatment of Mild Hyperkalemia in CKD.

PubMed

Lepage, Laurence; Dufour, Anne-Claude; Doiron, Jessica; Handfield, Katia; Desforges, Katherine; Bell, Robert; Vallée, Michel; Savoie, Michel; Perreault, Sylvie; Laurin, Louis-Philippe; Pichette, Vincent; Lafrance, Jean-Philippe

2015-12-07

Hyperkalemia affects up to 10% of patients with CKD. Sodium polystyrene sulfonate has long been prescribed for this condition, although evidence is lacking on its efficacy for the treatment of mild hyperkalemia over several days. This study aimed to evaluate the efficacy of sodium polystyrene sulfonate in the treatment of mild hyperkalemia. In total, 33 outpatients with CKD and mild hyperkalemia (5.0-5.9 mEq/L) in a single teaching hospital were included in this double-blind randomized clinical trial. We randomly assigned these patients to receive either placebo or sodium polystyrene sulfonate of 30 g orally one time per day for 7 days. The primary outcome was the comparison between study groups of the mean difference of serum potassium levels between the day after the last dose of treatment and baseline. The mean duration of treatment was 6.9 days. Sodium polystyrene sulfonate was superior to placebo in the reduction of serum potassium levels (mean difference between groups, -1.04 mEq/L; 95% confidence interval, -1.37 to -0.71). A higher proportion of patients in the sodium polystyrene sulfonate group attained normokalemia at the end of their treatment compared with those in the placebo group, but the difference did not reach statistical significance (73% versus 38%; P=0.07). There was a trend toward higher rates of electrolytic disturbances and an increase in gastrointestinal side effects in the group receiving sodium polystyrene sulfonate. Sodium polystyrene sulfonate was superior to placebo in reducing serum potassium over 7 days in patients with mild hyperkalemia and CKD. Copyright © 2015 by the American Society of Nephrology.

Randomized Clinical Trial of Sodium Polystyrene Sulfonate for the Treatment of Mild Hyperkalemia in CKD

PubMed Central

Lepage, Laurence; Dufour, Anne-Claude; Doiron, Jessica; Handfield, Katia; Desforges, Katherine; Bell, Robert; Vallée, Michel; Savoie, Michel; Perreault, Sylvie; Laurin, Louis-Philippe; Pichette, Vincent

2015-01-01

Background and objectives Hyperkalemia affects up to 10% of patients with CKD. Sodium polystyrene sulfonate has long been prescribed for this condition, although evidence is lacking on its efficacy for the treatment of mild hyperkalemia over several days. This study aimed to evaluate the efficacy of sodium polystyrene sulfonate in the treatment of mild hyperkalemia. Design, setting, participants, & measurements In total, 33 outpatients with CKD and mild hyperkalemia (5.0–5.9 mEq/L) in a single teaching hospital were included in this double–blind randomized clinical trial. We randomly assigned these patients to receive either placebo or sodium polystyrene sulfonate of 30 g orally one time per day for 7 days. The primary outcome was the comparison between study groups of the mean difference of serum potassium levels between the day after the last dose of treatment and baseline. Results The mean duration of treatment was 6.9 days. Sodium polystyrene sulfonate was superior to placebo in the reduction of serum potassium levels (mean difference between groups, −1.04 mEq/L; 95% confidence interval, −1.37 to −0.71). A higher proportion of patients in the sodium polystyrene sulfonate group attained normokalemia at the end of their treatment compared with those in the placebo group, but the difference did not reach statistical significance (73% versus 38%; P=0.07). There was a trend toward higher rates of electrolytic disturbances and an increase in gastrointestinal side effects in the group receiving sodium polystyrene sulfonate. Conclusions Sodium polystyrene sulfonate was superior to placebo in reducing serum potassium over 7 days in patients with mild hyperkalemia and CKD. PMID:26576619

21 CFR 178.3010 - Adjuvant substances used in the manufacture of foamed plastics.

Code of Federal Regulations, 2011 CFR

2011-04-01

... prescribed limitations: List of substances Limitations Azodicarbonamide For use as a blowing agent in pol... agent in polystyrene. Isopentane For use as a blowing agent in polystyrene. n-Pentane Do. 1,1,2,2-Tetra-chloroethylene For use only as a blowing agent adjuvant in polystyrene at a level not to exceed 0.3 percent by...

21 CFR 178.3010 - Adjuvant substances used in the manufacture of foamed plastics.

Code of Federal Regulations, 2012 CFR

2012-04-01

... prescribed limitations: List of substances Limitations Azodicarbonamide For use as a blowing agent in pol... agent in polystyrene. Isopentane For use as a blowing agent in polystyrene. n-Pentane Do. 1,1,2,2-Tetra-chloroethylene For use only as a blowing agent adjuvant in polystyrene at a level not to exceed 0.3 percent by...

21 CFR 178.3010 - Adjuvant substances used in the manufacture of foamed plastics.

Code of Federal Regulations, 2013 CFR

2013-04-01

... prescribed limitations: List of substances Limitations Azodicarbonamide For use as a blowing agent in pol... agent in polystyrene. Isopentane For use as a blowing agent in polystyrene. n-Pentane Do. 1,1,2,2-Tetra-chloroethylene For use only as a blowing agent adjuvant in polystyrene at a level not to exceed 0.3 percent by...

40 CFR 63.1318 - PET and polystyrene affected sources-testing and compliance demonstration provisions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 12 2013-07-01 2013-07-01 false PET and polystyrene affected sources... Pollutant Emissions: Group IV Polymers and Resins § 63.1318 PET and polystyrene affected sources—testing and... effectiveness) do not apply and owners or operators are not required to comply with § 63.113. (b) PET affected...

Nonstandard and Higher-Order Finite-Difference Methods for Electromagnetics

DTIC Science & Technology

2009-10-26

Simplified Fuselage filled with 90 passengers. . . . . . . . . 135 4.4. A top view photograph of the expanded polystyrene passenger support, and the... expanded polystyrene supports. . . . . . . . . . . . . . . . . . . . . . . 140 4.10. Measured S11 (the exterior antenna) of the simplified fuselage...escape. To keep the passengers in their designated locations and upright, an expanded polystyrene support system was made. In a sheet of 1” thick

AFM-based force spectroscopy on polystyrene brushes: effect of brush thickness on protein adsorption.

PubMed

Hentschel, Carsten; Wagner, Hendrik; Smiatek, Jens; Heuer, Andreas; Fuchs, Harald; Zhang, Xi; Studer, Armido; Chi, Lifeng

2013-02-12

Herein we present a study on nonspecific binding of proteins at highly dense packed hydrophobic polystyrene brushes. In this context, an atomic force microscopy tip was functionalized with concanavalin A to perform single-molecule force spectroscopy measurements on polystyrene brushes with thicknesses of 10 and 60 nm, respectively. Polystyrene brushes with thickness of 10 nm show an almost two times stronger protein adsorption than brushes with a thickness of 60 nm: 72 pN for the thinner and 38 pN for the thicker layer, which is in qualitative agreement with protein adsorption studies conducted macroscopically by fluorescence microscopy.

Grafted Polystyrene Monolayer Brush as Both Negative and Positive Tone Electron Beam Resist.

PubMed

Aydinoglu, Ferhat; Yamada, Hirotaka; Dey, Ripon K; Cui, Bo

2017-05-23

Although spin coating is the most widely used electron-beam resist coating technique in nanolithography, it cannot typically be applied for nonflat or irregular surfaces. Here, we demonstrate that monolayer polystyrene brush can be grafted on substrates and used as both positive and negative electron-beam resist, which can be applied for such unconventional surfaces. Polystyrene is a popular negative resist when using solvent developer but solvent cannot be used for grafted polystyrene brush that is firmly bonded to the substrate. Instead, we employed two unconventional development methods to lead polystyrene brush to positive or negative tone behavior. Negative tone was achieved by thermal development at 300 °C because exposed thus cross-linked polystyrene brush is more thermally stable against vaporization than unexposed linear one. Surprisingly, positive tone behavior occurred when the brush was grafted onto an aluminum (Al) layer and the film stack was developed using diluted hydrofluoric acid (HF) that etched the underlying Al layer. By transferring the patterns into the silicon (Si) substrates using the thin Al layer as a sacrificial hard mask for dry etch, well-defined structures in Si were obtained in two different electron-beam resist tones as well as in nonflat surfaces.

Synthesis and characterization of maleimide-functionalized polystyrene-SiO2/TiO2 hybrid nanocomposites by sol-gel process

NASA Astrophysics Data System (ADS)

Ramesh, Sivalingam; Sivasamy, Arumugam; Kim, Joo-Hyung

2012-06-01

Maleimide-functionalized polystyrene (PSMA-SiO2/TiO2) hybrid nanocomposites were prepared by sol-gel reaction starting from tratraethoxysilane (TEOS) and titanium isopropoxide in the solution of polystyrene maleimide in 1,4-dioxane. The hybrid films were obtained by the hydrolysis and polycondensation of TEOS and titanium isopropoxide in maleimide-functionalized polystyrene solution followed by the Michael addition reaction. The transparency of polymer (PSMA-SiO2/TiO2) hybrid was prepared from polystyrene titanium isopropoxide using the γ-aminopropyltriethoxy silane as crosslinking agent by in situ sol-gel process via covalent bonding between the organic-inorganic hybrid nanocomposites. The maleimide-functionalized polystyrene was synthesized by Friedel-Crafts reaction from N-choloromethyl maleimide. The FTIR spectroscopy data conformed the occurrence of Michael addition reaction between the pendant maleimide moieties of the styrene and γ-aminopropyltriethoxysilane. The chemical structure and morphology of PSMA-SiO2/TiO2 hybrid nanocomposites were characterized by FTIR, nuclear magnetic resonance (NMR), 13 C NMR, SEM, XRD, and TEM analyses. The results also indicate that the inorganic particles are much smaller in the ternary systems than in the binary systems; the shape of the inorganic particles and compatibility for maleimide-functionalized polystrene and inorganic moieties are varied with the ratio of the inorganic moieties in the hybrids. Furthermore, TGA and DSC results indicate that the thermal stability of maleimide-functionalized polystyrene was enhanced through the incorporation of the inorganic moieties in the hybrid materials.

Simulation of Prestressed Concrete Sandwich Panels Subjected to Blast Loads (Preprint)

DTIC Science & Technology

2010-02-01

configuration. Conventionally reinforced panels had configurations of 3-2-3 a nd 6-2-3. Insulating foams included expanded polystyrene , extruded expanded ...Properties of Extruded Expanded Polystyrene Foam Building Materials. M.S.C.E. report, University of Alabama at Birmingham. Livermore Software... polystyrene , and polyisocyanurate. Compressive testing of insulating f oams used as construction materials was used to define the stress/strain

Preparation of polystyrene brush film by radical chain-transfer polymerization and micromechanical properties

NASA Astrophysics Data System (ADS)

Zhao, Jing; Chen, Miao; An, Yanqing; Liu, Jianxi; Yan, Fengyuan

2008-12-01

A radical chain-transfer polymerization technique has been applied to graft-polymerize brushes of polystyrene (PSt) on single-crystal silicon substrates. 3-Mercapto-propyltrimethoxysilane (MPTMS), as a chain-transfer agent for grafting, was immobilized on the silicon surface by a self-assembling process. The structure and morphology of the graft-functionalized silicon surfaces were characterized by the means of contact-angle measurement, ellipsometric thickness measurement, Fourier transformation infrared (FTIR) spectroscopy, and atomic force microscopy (AFM). The nanotribological and micromechanical properties of the as-prepared polymer brush films were investigated by frictional force microscopy (FFM), force-volume analysis and scratch test. The results indicate that the friction properties of the grafted polymer films can be improved significantly by the treatment of toluene, and the chemically bonded polystyrene film exhibits superior scratch resistance behavior compared with the spin-coated polystyrene film. The resultant polystyrene brush film is expected to develop as a potential lubrication coating for microelectromechanical systems (MEMS).

Pore Structure and Fluoride Ion Adsorption Characteristics of Zr (IV) Surface-Immobilized Resin Prepared Using Polystyrene as a Porogen

NASA Astrophysics Data System (ADS)

Mizuki, Hidenobu; Ito, Yudai; Harada, Hisashi; Uezu, Kazuya

Zr(IV) surface-immobilized resins for removal of fluoride ion were prepared by surface template polymerization using polystyrene as a porogen. At polymerization, polystyrene was added in order to increase mesopores (2-50 nm) and macropore (>50 nm) with large macropores (around 300 nm) formed with internal aqueous phase of W⁄O emulsion. The pore structure of Zr(IV) surface-immobilized resins was evaluated by measuring specific surface area, pore volume, and pore size distribution with volumetric adsorption measurement instrument and mercury porosimeter. The adsorption isotherms were well fitted by Langmuir equation. The removal of fluoride was also carried out with column method. Zr(IV) surface-immobilized resins, using 10 g⁄L polystyrene in toluene at polymerization, possessed higher volume of not only mesopores and macropores but also large macropores. Furethermore, by adding the polystyrene with smaller molecular size, the pore volume of mesopores, macropores and large macropores was significantly increased, and the fluoride ion adsorption capacity and the column utilization also increased.

Ceramic Spheres From Cation Exchange Beads

NASA Technical Reports Server (NTRS)

Dynys, F. W.

2003-01-01

Porous ZrO2 and hollow TiO2 spheres were synthesized from a strong acid cation exchange resin. Spherical cation exchange beads, polystyrene based polymer, were used as a morphological-directing template. Aqueous ion exchange reaction was used to chemically bind (ZrO)(2+) ions to the polystyrene structure. The pyrolysis of the polystyrene at 600 C produces porous ZrO2 spheres with a surface area of 24 sq m/g with a mean sphere size of 42 microns. Hollow TiO2 spheres were synthesized by using the beads as a micro-reactor. A direct surface reaction - between titanium isopropoxide and the resin beads forms a hydrous TiO2 shell around the polystyrene core. The pyrolysis of the polystyrene core at 600 C produces hollow anatase spheres with a surface area of 42 sq m/g with a mean sphere size of 38 microns. The formation of ceramic spheres was studied by XRD, SEM and B.E.T. nitrogen adsorption measurements.

Sulfonated polystyrene and its characterization as a material of electrolyte polymer

NASA Astrophysics Data System (ADS)

Ngadiwiyana; Ismiyarto; Gunawan; Purbowatiningrum, RS; Prasetya, N. B. A.; Kusworo, T. D.; Susanto, H.

2018-05-01

The research of polystyrene modification from Styrofoam waste and its application as a main material of electrolyte polymer had been done. The sulfonation reaction of polystyrene was conducted using sulfuric acid as sufonation agent and the reactions were done with variation times of 1, 2, 3, 4 and 5 h. The characterization of the sulfonated products covered analysis of functional groups using FT-IR spectrophotometer, sulfonation degree, measurements of ion exchange capacity, conductivity and swelling degree. The sulfonated polystyrene product was white solid as confirmed by the spectra of FT-IR with the presence of wide band absorption of O=S=O at the wavenumber of 1080-1411 cm-1 as indication. The research showed the best sulfonated polystyrene prepared in 4 h as a material of electrolyte polymer, since it had the highest degree of sulfonation, ion exchange capacity, conductivity and swelling degree with the values were 28.52 %, 1.550 meg/g, 15,924.10-6 Ω-1cm-1 and 332.4 %, respectively.

Novel one-step route for synthesizing CdS/polystyrene nanocomposite hollow spheres.

PubMed

Wu, Dazhen; Ge, Xuewu; Zhang, Zhicheng; Wang, Mozhen; Zhang, Songlin

2004-06-22

CdS/polystyrene nanocomposite hollow spheres with diameters between 240 and 500 nm were synthesized under ambient conditions by a novel microemulsion method in which the polymerization of styrene and the formation of CdS nanoparticles were initiated by gamma-irradiation. The product was characterized by transmission electron microscopy (TEM), field-emission scanning electron microscopy (FESEM), X-ray powder diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and thermogravimetric analysis (TGA), which show the walls of the hollow spheres are porous and composed of polystyrene containing homogeneously dispersed CdS nanoparticles. The quantum-confined effect of the CdS/polystyrene nanocomposite hollow spheres is confirmed by the ultraviolet-visible (UV-vis) and photoluminescent (PL) spectra. We propose that the walls of these nanocomposite hollow spheres originate from the simultaneous synthesis of polystyrene and CdS nanoparticles at the interface of microemulsion droplets. This novel method is expected to produce various inorganic/polymer nanocomposite hollow spheres with potential applications in the fields of materials science and biotechnology.

Design and Development of E3 Antenna Container,

DTIC Science & Technology

1985-09-03

reinforced with square tubing. The walls and ceiling shall be insulated with expanded polystyrene . TEST LOCATION - This test will be performed at the...ceiling shall be insulated with expanded polystyrene . TEST LOCATION - This test will be performed at the Edgewater Machine & Fabricator’s facility...insulated with expanded polystyrene . TEST LOCATION - This test will be performed at the Edgewater Machine & Fabricator’s facility located at 200 N

New Concept Study for Repair of Bomb-Damaged Runways. Volume I. Concept Identification.

DTIC Science & Technology

1979-09-01

Expanded polystyrene beads would be pneumatically mixed with the cement to form a low density material. Initially, the ratio of foam to cement would...the combinations are presented with this concept. PRIMARY MATERIALS 0 Expanded polystyrene foam beads * Graded aggregate * Quick setting cement 61 E-4...probability of success - high ALTERNATE MATERIALS * Expanded polystyrene foam beads * Organic binders Furan Methyl Methacrylate Epoxy Aminos * Graded

Pyrolysis of polystyrene - polyphenylene oxide to recover styrene and useful products

DOEpatents

Evans, Robert J.; Chum, Helena L.

1995-01-01

A process of using fast pyrolysis in a carrier gas to convert a polystyrene and polyphenylene oxide plastic waste to a given polystyrene and polyphenylene oxide prior to pyrolysis of other plastic components therein comprising: selecting a first temperature range to cause pyrolysis of given polystyrene and polyphenylene oxide and its high value monomeric constituent prior to a temperature range that causes pyrolysis of other plastic components; selecting a catalyst and a support and treating the feed stream with the catalyst to affect acid or base catalyzed reaction pathways to maximize yield or enhance separation of high value monomeric constituent of styrene from polystyrene and polyphenylene oxide in the first temperature range; differentially heating the feed stream at a heat rate within the first temperature range to provide differential pyrolysis for selective recovery of the high value monomeric constituent of styrene from polystyrene and polyphenylene oxide prior to pyrolysis of other plastic components; separating the high value monomer constituent of styrene; selecting a second higher temperature range to cause pyrolysis to a different derived high value product of polyphenylene oxide from the plastic waste and differentially heating the feed stream at the higher temperature range to cause pyrolysis of the plastic into a polyphenylene oxide derived product; and separating the different derived high value polyphenylene oxide product.

Solid polystyrene and deuterated polystyrene light output response to fast neutrons

NASA Astrophysics Data System (ADS)

Simpson, R.; Danly, C.; Glebov, V. Yu.; Hurlbut, C.; Merrill, F. E.; Volegov, P. L.; Wilde, C.

2016-04-01

The Neutron Imaging System has proven to be an important diagnostic in studying DT implosion characteristics at the National Ignition Facility. The current system depends on a polystyrene scintillating fiber array, which detects fusion neutrons born in the DT hotspot as well as neutrons that have scattered to lower energies in the surrounding cold fuel. Increasing neutron yields at NIF, as well as a desire to resolve three-dimensional information about the fuel assembly, have provided the impetus to build and install two additional next-generation neutron imaging systems. We are currently investigating a novel neutron imaging system that will utilize a deuterated polystyrene (CD) fiber array instead of standard hydrogen-based polystyrene (CH). Studies of deuterated xylene or deuterated benzene liquid scintillator show an improvement in imaging resolution by a factor of two [L. Disdier et al., Rev. Sci. Instrum. 75, 2134 (2004)], but also a reduction in light output [V. Bildstein et al., Nucl. Instrum. Methods Phys. Res., Sect. A 729, 188 (2013); M. I. Ojaruega, Ph.D. thesis, University of Michigan, 2009; M. T. Febbraro, Ph.D. thesis, University of Michigan, 2014] as compared to standard plastic. Tests of the relative light output of deuterated polystyrene and standard polystyrene were completed using 14 MeV fusion neutrons generated through implosions of deuterium-tritium filled capsules at the OMEGA laser facility. In addition, we collected data of the relative response of these two scintillators to a wide energy range of neutrons (1-800 MeV) at the Weapons Neutrons Research Facility. Results of these measurements are presented.

Solid polystyrene and deuterated polystyrene light output response to fast neutrons.

PubMed

Simpson, R; Danly, C; Glebov, V Yu; Hurlbut, C; Merrill, F E; Volegov, P L; Wilde, C

2016-04-01

The Neutron Imaging System has proven to be an important diagnostic in studying DT implosion characteristics at the National Ignition Facility. The current system depends on a polystyrene scintillating fiber array, which detects fusion neutrons born in the DT hotspot as well as neutrons that have scattered to lower energies in the surrounding cold fuel. Increasing neutron yields at NIF, as well as a desire to resolve three-dimensional information about the fuel assembly, have provided the impetus to build and install two additional next-generation neutron imaging systems. We are currently investigating a novel neutron imaging system that will utilize a deuterated polystyrene (CD) fiber array instead of standard hydrogen-based polystyrene (CH). Studies of deuterated xylene or deuterated benzene liquid scintillator show an improvement in imaging resolution by a factor of two [L. Disdier et al., Rev. Sci. Instrum. 75, 2134 (2004)], but also a reduction in light output [V. Bildstein et al., Nucl. Instrum. Methods Phys. Res., Sect. A 729, 188 (2013); M. I. Ojaruega, Ph.D. thesis, University of Michigan, 2009; M. T. Febbraro, Ph.D. thesis, University of Michigan, 2014] as compared to standard plastic. Tests of the relative light output of deuterated polystyrene and standard polystyrene were completed using 14 MeV fusion neutrons generated through implosions of deuterium-tritium filled capsules at the OMEGA laser facility. In addition, we collected data of the relative response of these two scintillators to a wide energy range of neutrons (1-800 MeV) at the Weapons Neutrons Research Facility. Results of these measurements are presented.

Solid polystyrene and deuterated polystyrene light output response to fast neutrons

DOE Office of Scientific and Technical Information (OSTI.GOV)

Simpson, R., E-mail: raspberry@lanl.gov; Danly, C.; Merrill, F. E.

The Neutron Imaging System has proven to be an important diagnostic in studying DT implosion characteristics at the National Ignition Facility. The current system depends on a polystyrene scintillating fiber array, which detects fusion neutrons born in the DT hotspot as well as neutrons that have scattered to lower energies in the surrounding cold fuel. Increasing neutron yields at NIF, as well as a desire to resolve three-dimensional information about the fuel assembly, have provided the impetus to build and install two additional next-generation neutron imaging systems. We are currently investigating a novel neutron imaging system that will utilize amore » deuterated polystyrene (CD) fiber array instead of standard hydrogen-based polystyrene (CH). Studies of deuterated xylene or deuterated benzene liquid scintillator show an improvement in imaging resolution by a factor of two [L. Disdier et al., Rev. Sci. Instrum. 75, 2134 (2004)], but also a reduction in light output [V. Bildstein et al., Nucl. Instrum. Methods Phys. Res., Sect. A 729, 188 (2013); M. I. Ojaruega, Ph.D. thesis, University of Michigan, 2009; M. T. Febbraro, Ph.D. thesis, University of Michigan, 2014] as compared to standard plastic. Tests of the relative light output of deuterated polystyrene and standard polystyrene were completed using 14 MeV fusion neutrons generated through implosions of deuterium-tritium filled capsules at the OMEGA laser facility. In addition, we collected data of the relative response of these two scintillators to a wide energy range of neutrons (1-800 MeV) at the Weapons Neutrons Research Facility. Results of these measurements are presented.« less

Experimental Results of Multiple Scattering.

DTIC Science & Technology

1980-07-01

error is seen to be less for targets with smaller IS()I/IS(O)Iratio like the softer particles made from expanded polystyrene and larger for harder...optical spectrum, we also notice marked differences from the P, Q plots of dylite ( expanded polystyrene ) particles in preceding sections. It was...spheres made of expanded polystyrene . As X is continuously varied for the display of if(e) , we notice a fairly symmetrical intensity profile about X = 8/2

Gravity Effects in Small-Scale Structural Modeling

DTIC Science & Technology

1988-12-01

attenuating material (Reference 23). The materials tested were cellular concrete with fly ash, expanded polystyrene concrete with fly ash, foamed...polyurethane, foamed sulfer and molded expanded polystyrene . The studies showed that with proper adjustments in the cement content, water-cement ratio and foam...Compression (Ou,c) 4000 100 Tension (Ou,t) 400 10 E/Quc 1000 1000 Ou,c/Ou,t 10 10 Further analysis of the properties of expanded polystyrene concrete with

Weathering Tests on Protective Helmets Approved to Australian Standard AS 1698 (for Vehicle Users).

DTIC Science & Technology

1979-11-01

Expanded Polystyrene HELMETI Colour Production; SAA Size ,Length Width j Mass Circumference Date Serial No. cm imm mm nu qm nun L A White July 󈨒 B535336...HELMET DETAILS Make: ARAI Model: S-75 Shell: Fibreglass Reinforced Polyester Resin Liner: Expanded Polystyrene HELMET Colour Production SAA Size...Reinforced Polyester Resin Liner; Expanded Polystyrene (with thin plastic inner shell) HELMET Colour Production’ SAA Size Length Width Mass

Experimental Results of Multiple Scattering.

DTIC Science & Technology

1981-11-01

fixed, the error is seen to be less for targets with smaller IJ(i)/S(O)Iratio like the softer particles made from expanded polystyrene and larger for...differences from the P, Q plots of dylite ( expanded polystyrene ) particles in preceding sections. It was rather difficult to prepare more than two identical...contacting identical spheres made of expanded polystyrene . As X is continuously varied for the display of il(e) , we notice a fairly symmetrical

Fabrication of sub-micrometer-sized jingle bell-shaped hollow spheres from multilayered core-shell particles.

PubMed

Gu, Shunchao; Kondo, Tomohiro; Mine, Eiichi; Nagao, Daisuke; Kobayashi, Yoshio; Konno, Mikio

2004-11-01

Jingle bell-shaped hollow spheres were fabricated starting from multilayered particles composed of a silica core, a polystyrene inner shell, and a titania outer shell. Composite particles of silica core-polystyrene shell, synthesized by coating a 339-nm-sized silica core with a polystyrene shell of thickness 238 nm in emulsion polymerization, were used as core particles for a succeeding titania-coating. A sol-gel method was employed to form the titania outer shell with a thickness of 37 nm. The inner polystyrene shell in the multilayered particles was removed by immersing them in tetrahydrofuran. These successive procedures could produce jingle bell-shaped hollow spheres that contained a silica core in the titania shell.

Copolymers of fluorinated polydienes and sulfonated polystyrene

DOEpatents

Mays, Jimmy W [Knoxville, TN; Gido, Samuel P [Hadley, MA; Huang, Tianzi [Knoxville, TN; Hong, Kunlun [Knoxville, TN

2009-11-17

Copolymers of fluorinated polydienes and sulfonated polystyrene and their use in fuel cell membranes, batteries, breathable chemical-biological protective materials, and templates for sol-gel polymerization.

Osteoblasts generate harder, stiffer, and more delamination-resistant mineralized tissue on titanium than on polystyrene, associated with distinct tissue micro- and ultrastructure.

PubMed

Saruwatari, Lei; Aita, Hideki; Butz, Frank; Nakamura, Hiromi K; Ouyang, Jianyong; Yang, Yang; Chiou, Wen-An; Ogawa, Takahiro

2005-11-01

This study revealed that osteoblasts generate harder, stiffer, and more delamination-resistant mineralized tissue on titanium than on the tissue culture polystyrene, associated with modulated gene expression, uniform mineralization, well-crystallized interfacial calcium-phosphate layer, and intensive collagen deposition. Knowledge of this titanium-induced alteration of osteogenic potential leading to enhanced intrinsic biomechanical properties of mineralized tissue provides novel opportunities and implications for understanding and improving bone-titanium integration and engineering physiomechanically tolerant bone. Bone-titanium integration is a biological phenomenon characterized by continuous generation and preservation of peri-implant bone and serves as endosseous anchors against endogenous and exogenous loading, of which mechanisms are poorly understood. This study determines the intrinsic biomechanical properties and interfacial strength of cultured mineralized tissue on titanium and characterizes the tissue structure as possible contributing factors in biomechanical modulation. Rat bone marrow-derived osteoblastic cells were cultured either on a tissue culture-grade polystyrene dish or titanium-coated polystyrene dish having comparable surface topography. Nano-indentation and nano-scratch tests were undertaken on mineralized tissues cultured for 28 days to evaluate its hardness, elastic modulus, and critical load (force required to delaminate tissue). Gene expression was analyzed using RT-PCR. The tissue structural properties were examined by scanning electron microscopy (SEM), collagen colorimetry and localization with Sirius red stain, mineral quantification, and localization with von Kossa stain and transmission electron microscopy (TEM). Hardness and elastic modulus of mineralized tissue on titanium were three and two times greater, respectively, than those on the polystyrene. Three times greater force was required to delaminate the tissue on titanium than that on the polystyrene. SEM of the polystyrene culture displayed a porous structure consisting of fibrous and globular components, whereas the titanium tissue culture appeared to be uniformly solid. Cell proliferation was remarkably reduced on titanium. Microscopic observations revealed that the mineralized tissue on titanium was composed of uniform collagen-supported mineralization from the titanium interface to the outer surface, with intensive collagen deposition at tissue-titanium interface. In contrast, tissue on the polystyrene was characterized by collagen-deficient mineralization at the polystyrene interface and calcium-free collagenous matrix formation in the outer tissue area. Such characteristic microstructure of titanium-associated tissue was corresponded with upregulated gene expression of collagen I and III, osteopontin, and osteocalcin mRNA. Cross-sectional TEM revealed the apposition of a high-contrast and well-crystallized calcium phosphate layer at the titanium interface but not at the polystyrene interface. Culturing osteoblasts on titanium, compared with polystyrene, enhances the hardness, elastic modulus, and interfacial strength of mineralized tissue to a higher degree. Titanium per se possesses an ability to alter cellular phenotypes and tissue micro- and ultrastructure that result in enhanced intrinsic biomechanical properties of mineralized tissue.

Relative merits of polystyrene foam and paper in hot drink cups: Implications for packaging

NASA Astrophysics Data System (ADS)

Hocking, Martin B.

1991-11-01

An analysis of the overall relative merits of the use of uncoated paper vs molded polystyrene bead foam in single-use 8-oz cups is described here as a manageable example of the use of paper vs plastics in packaging. In raw material requirements the paper cup required about 2.5 times its finished weight of raw wood and about the same hydrocarbon fueling requirement as is needed for the polystyrene foam cup. To process the raw materials about six times as much steam, 13 times as much electric power, and twice as much cooling water are consumed to produce the paper cup as compared to the polystyrene foam cup. Emission rates to air are similar and to water are generally higher for the paper cup. Virtually all primary use factors favor polystyrene foam over paper. Once used both cup types may be recycled. Landfill disposal of the two items under dry conditions will occupy similar landfill volumes after compaction and will confer similarly slow to nonexistent decomposition to either option. Under wet conditions polystyrene foam will not readily degrade, but may help other materials to do so. Paper under wet conditions will biodegrade to produce methane, a significant greenhouse gas, biochemical oxygen demand to any leachate, and instability to the land surface during the process. Both materials can be incinerated cleanly in a municipal waste stream with the option of energy recovery, to yield an ash volume of 2% 5% of the incoming waste volume. Overall this analysis would suggest that polystyrene foam, with an extension to plastics in general, should be given more evenhanded consideration relative to paper in packaging applications than is currently the case.

Impact of water chemistry on surface charge and aggregation of polystyrene microspheres suspensions.

PubMed

Lu, Songhua; Zhu, Kairuo; Song, Wencheng; Song, Gang; Chen, Diyun; Hayat, Tasawar; Alharbi, Njud S; Chen, Changlun; Sun, Yubing

2018-07-15

The discharge of microplastics into aquatic environment poses the potential threat to the hydrocoles and human health. The fate and transport of microplastics in aqueous solutions are significantly influenced by water chemistry. In this study, the effect of water chemistry (i.e., pH, foreign salts and humic acid) on the surface charge and aggregation of polystyrene microsphere in aqueous solutions was conducted by batch, zeta potentials, hydrodynamic diameters, FT-IR and XPS analysis. Compared to Na + and K + , the lower negative zeta potentials and larger hydrodynamic diameters of polystyrene microspheres after introduction of Mg 2+ were observed within a wide range of pH (2.0-11.0) and ionic strength (IS, 0.01-500mmol/L). No effect of Cl - , HCO 3 - and SO 4 2- on the zeta potentials and hydrodynamic diameters of polystyrene microspheres was observed at low IS concentrations (<5mmol/L), whereas the zeta potentials and hydrodynamic diameters of polystyrene microspheres after addition of SO 4 2- were higher than that of Cl - and HCO 3 - at high IS concentrations (>10mmol/L). The zeta potentials of polystyrene microspheres after HA addition were decreased at pH2.0-11.0, whereas the lower hydrodynamic diameters were observed at pH<4.0. According to FT-IR and XPS analysis, the change in surface properties of polystyrene microspheres after addition of hydrated Mg 2+ and HA was attributed to surface electrostatic and/or steric repulsions. These investigations are crucial for understanding the effect of water chemistry on colloidal stability of microplastics in aquatic environment. Copyright © 2018 Elsevier B.V. All rights reserved.

Liquid-liquid phase separation in dilute solutions of poly(styrene sulfonate) with multivalent cations: Phase diagrams, chain morphology, and impact of temperature

NASA Astrophysics Data System (ADS)

Hansch, Markus; Hämisch, Benjamin; Schweins, Ralf; Prévost, Sylvain; Huber, Klaus

2018-01-01

The dilute solution behavior of sodium poly(styrene sulfonate) is studied in the presence of trivalent Al3+ and bivalent Ba2+ cations at various levels of excess NaCl. The study evaluates the phase behavior and the morphology of the polyelectrolyte chains with increasing extent of decoration with the Al3+ and Ba2+ cations and analyses the effect of temperature on these decorated chains. The phase behavior is presented in the form of the cation concentration versus the respective poly(styrene sulfonate) concentration, recorded at the onset of precipitation. Whereas poly(styrene sulfonate) with Al3+ exhibits a linear phase boundary, denoted as the "threshold line," which increases with increasing poly(styrene sulfonate) concentration, Ba2+ cations show a threshold line which is independent of the poly(styrene sulfonate) concentration. An additional re-entrant phase, at considerably higher cation content than those of the threshold lines, is observed with Al3+ cations but not with Ba2+ cations. The threshold line and the re-entrant phase boundary form parts of the liquid-liquid phase boundary observed at the limit of low polymer concentration. The dimensions of the polyelectrolyte chains shrink considerably while approaching the respective threshold lines on increase of the Al3+ and Ba2+ cation content. However, subtle differences occur between the morphological transformation induced by Al3+ and Ba2+. Most strikingly, coils decorated with Al3+ respond very differently to temperature variations than coils decorated with Ba2+ do. As the temperature increases, the poly(styrene sulfonate) chains decrease their size in the presence of Al3+ cations but increase in size in the presence of Ba2+ cations.

Polystyrene/Hyperbranched Polyester Blends and Reactive Polystyrene/Hyperbranched Polyester Blends

DTIC Science & Technology

1999-01-01

interfacial tension between the PE and polystyrene phases. This was brought about by the chemical interaction between the acidic anhydride groups in the...multiple 2,2 dimethylol propionic acid (C5H10O4) chain extenders or repeat units. 11 Core HO \\ HO’ /■ J OH V *OH Pentaerythritol Chain Extender...O 2,2 - Dimethylol propionic acid Figure 11. HBP Building Blocks. These materials were supplied in small quantities with little technical data. The

Discovery of a polystyrene binding peptide isolated from phage display library and its application in peptide immobilization.

PubMed

Qiang, Xu; Sun, Keyong; Xing, Lijun; Xu, Yifeng; Wang, Hong; Zhou, Zhengpin; Zhang, Juan; Zhang, Fang; Caliskan, Bilgen; Wang, Min; Qiu, Zheng

2017-06-01

Phage peptide display is a powerful technique for discovery of various target-specific ligands. However, target-unrelated peptides can often be obtained and cause ambiguous results. Peptide PB-TUP has been isolated repeatedly in our laboratory on different targets and we conducted a research on PB-TUP phage to investigate their binding properties and rate of propagation. ELISA and phage recovery assay demonstrated that PB-TUP phage had a significant superior affinity to polystyrene solid surface compared with control phage clones. In this study, some incidental bindings are excluded like blocking agents and non-specific binding of secondary antibodies. Propagation rate assays of the selected phage clones showed that the growth rate of PB-TUP phage was not superior to the control phages. Furthermore, the binding of PB-TUB to polystyrene was concentration dependent and varied with solution pH. Molecular modeling revealed that stable structures of α-helix and β-turn may contribute to the binding of PB-TUP to polystyrene plate. The PB-TUP sequence was fused to the N-terminus of peptide P2 and the fusion peptide significantly increased the binding affinity to polystyrene. The fusion peptide also enhanced the cell adhesion ability of peptide P2 with human umbilical vein endothelial cell (HUVEC). The addition of the polystyrene binding peptide provided a convenient method for peptide immobilization.

Migration of lymphocytes on fibronectin-coated surfaces: temporal evolution of migratory parameters

NASA Technical Reports Server (NTRS)

Bergman, A. J.; Zygourakis, K.; McIntire, L. V. (Principal Investigator)

1999-01-01

Lymphocytes typically interact with implanted biomaterials through adsorbed exogenous proteins. To provide a more complete characterization of these interactions, analysis of lymphocyte migration on adsorbed extracellular matrix proteins must accompany the commonly performed adhesion studies. We report here a comparison of the migratory and adhesion behavior of Jurkat cells (a T lymphoblastoid cell line) on tissue culture treated and untreated polystyrene surfaces coated with various concentrations of fibronectin. The average speed of cell locomotion showed a biphasic response to substrate adhesiveness for cells migrating on untreated polystyrene and a monotonic decrease for cells migrating on tissue culture-treated polystyrene. A modified approach to the persistent random walk model was implemented to determine the time dependence of cell migration parameters. The random motility coefficient showed significant increases with time when cells migrated on tissue culture-treated polystyrene surfaces, while it remained relatively constant for experiments with untreated polystyrene plates. Finally, a cell migration computer model was developed to verify our modified persistent random walk analysis. Simulation results suggest that our experimental data were consistent with temporally increasing random motility coefficients.

Influence of physicochemical properties of laser-modified polystyrene on bovine serum albumin adsorption and rat C6 glioma cell behavior.

PubMed

Wang, Xuefeng; Ohlin, C André; Lu, Qinghua; Hu, Jun

2006-09-15

Biomaterial surface modification is an efficient way of improving cell-material interactions. In this study, sub-micrometer laser-induced periodic surface structures (LIPSS) were produced on polystyrene by laser irradiation. FT-IR analysis confirmed that this treatment also led to surface oxidation and anisotropic orientation of the produced carbonyl groups. As a consequence, the surface energy of the laser-treated polystyrene was 1.45 times that of the untreated polystyrene, as measured by contact-angle goniometry. Protein adsorption and rat C6 glioma cell behavior on the two substrates were investigated, showing that the changed physicochemical properties of laser-modified polystyrene surface led to an increase in the quantity of adsorbed bovine serum albumin and significantly affected the behavior of rat C6 glioma cells. In the early stages of cell spreading, cells explored their microenvironment using filopodium as the main sensor. Moreover, cells actively aligned themselves along the direction of LIPSS gradually and cell attachment and proliferation were significantly enhanced. 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006.

MOF-5-Polystyrene: Direct Production from Monomer, Improved Hydrolytic Stability, and Unique Guest Adsorption.

PubMed

Gamage, Nipuni-Dhanesha H; McDonald, Kyle A; Matzger, Adam J

2016-09-19

An unprecedented mode of reactivity of Zn4 O-based metal-organic frameworks (MOFs) offers a straightforward and powerful approach to polymer-hybridized porous solids. The concept is illustrated with the production of MOF-5-polystyrene wherein polystyrene is grafted and uniformly distributed throughout MOF-5 crystals after heating in pure styrene for 4-24 h. The surface area and polystyrene content of the material can be fine-tuned by controlling the duration of heating styrene in the presence of MOF-5. Polystyrene grafting significantly alters the physical and chemical properties of pristine MOF-5, which is evident from the unique guest adsorption properties (solvatochromic dye uptake and improved CO2 capacity) as well as the dramatically improved hydrolytic stability of composite. Based on the fact that MOF-5 is the best studied member of the structure class, and has been produced at scale by industry, these findings can be directly leveraged for a range of current applications. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Ionoluminescence properties of polystyrene-hosted fluorophore films induced by helium ions of energy 50-350 keV

NASA Astrophysics Data System (ADS)

Chakraborty, Subha; Huang, Mengbing

2017-10-01

We report on measurements and analysis of ionoluminescence properties of pure polystyrene films and polystyrene films doped with four types of fluorophores in low kinetic energies (50-350 keV) of ion irradiation. We have developed a theoretical model to understand the experimentally observed ionoluminescence behaviors in terms of scintillation yield from individual ion tracks, photophysical energy transfer mechanisms, and irradiation-induced defects. A comparison of the model and experimental results suggests that singlet up-conversion resulting from triplet-triplet annihilation processes may be responsible for enhanced singlet emission of the fluorophores at high ion beam flux densities. Energy transfer from the polystyrene matrix to the fluorophore molecules has been identified as an effective pathway to increasing the fluorescence efficiency in the doped scintillator films.

Few-layer graphene growth from polystyrene as solid carbon source utilizing simple APCVD method

NASA Astrophysics Data System (ADS)

Ahmadi, Shahrokh; Afzalzadeh, Reza

2016-07-01

This research article presents development of an economical, simple, immune and environment friendly process to grow few-layer graphene by controlling evaporation rate of polystyrene on copper foil as catalyst and substrate utilizing atmospheric pressure chemical vapor deposition (APCVD) method. Evaporation rate of polystyrene depends on molecular structure, amount of used material and temperature. We have found controlling rate of evaporation of polystyrene by controlling the source temperature is easier than controlling the material weight. Atomic force microscopy (AFM) as well as Raman Spectroscopy has been used for characterization of the layers. The frequency of G‧ to G band ratio intensity in some samples varied between 0.8 and 1.6 corresponding to few-layer graphene. Topography characterization by atomic force microscopy confirmed Raman results.

Glass transition behavior of polystyrene/silica nanocomposites.

NASA Astrophysics Data System (ADS)

Xie, Yuping; Sen, Sudeepto; Kumar, Sanat; Bansal, Amitabh

2006-03-01

The change in thermomechanical properties of nano-filled polymers is of considerable scientific and technological interest. The interaction between the nanofillers and the matrix polymer controls the nanocomposite properties. We will present the results from recent and ongoing DSC experiments on polystyrene/silica nanocomposites. Polystyrene of different molecular weights (and from different sources) and silica nanoparticles 10-15 nm in diameter (both as received from Nissan and surface modified by grafted or physisorbed polystyrene) are being used to process the nanocomposites. We are studying trends in the glass transition behavior by changing the matrix molecular weights and the silica weight fractions. Recent data indicate that the glass transition temperature can both decrease and increase depending on the polymer-nanofiller combination as well as the thermal treatment of the nanocomposites prior to the DSC runs.

Abbe's number and Cauchy's constant of iodine and selenium doped poly (methylmethacrylate) and polystyrene composites

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mehta, Sheetal, E-mail: smehta-29@yahoo.com; Das, Kallol, E-mail: smehta-29@yahoo.com; Keller, Jag Mohan, E-mail: smehta-29@yahoo.com

2014-04-24

Poly (methyl methacrylate) / Polystyrene and iodine / selenium hybrid matrixes have been prepared and characterized. Refractive index measurements were done at 390, 535, 590, 635 nm wavelengths. Abbe's number and Cauchy's constants of the iodine / selenium doped poly (methylmethacrylate) and polystyrene samples are being reported. The results also showed that the refractive index of the composite varies non-monotonically with the doping concentration at low iodine concentration or in the region of nanoparticles formation and is also dependent on thermal annealing.

Inflow Ducting in High-Volume-Flow Subsonic Anechoic Chambers.

DTIC Science & Technology

1983-10-12

resin with 1/4" (6.4mm) thick walls and its inner diameter is 9 1/2" (21.4cm). A bellmouth was fabricated from expanded polystyrene and fitted to the...is modeled with steel-angle-reinforced 1/4" (6.4mm) plywood walls that are lined with expanded polystyrene wedges. Great care was taken during the...t, mounted, the wedges are made of expanded polystyrene , and were cut to shape by the supplier with a hot wire system. The wedges are p

Evaluation of Test Methods To Determine the Impact Resistance of Exterior Insulation and Finish Systems (EIFS).

DTIC Science & Technology

1992-07-01

be used effectively in new construction or retrofit applications. These systems usually contain: 1. Molded expanded polystyrene insulation board (MEPS...commonly referred to as "bead board," or extruded expanded polystyrene insulation board (XEPS), commonly referred to as "blue board." 2. An...Walls ( Expanded Polystyrene Insulation Faced with a Thin Rendering), M.O.A.T. n 22, June 1988. 7 ASTM D3029-90. "Standard Test Methods for Impact

Testing of Shelter Design and Industrial Hardening Concepts at the MILL RACE Event.

DTIC Science & Technology

1982-01-01

built. The upgrading consisted of the application of 2-in. thick sheets of expanded polystyrene to the exterior of each of the test walls to be upgraded...was covered with 1-in. thick sheets of expanded polystyrene prior to backfilling (Figure 6-4), and the interior was shored, floor to ceiling, with two...deformations in the vault, despite the fact that no structural upgrading options (shores, or roof cover of expanded polystyrene ) were installed. Thus

Flotation Analysis for Boat Docks on U.S. Army Corps of Engineers Projects. Recreation Management Support Program

DTIC Science & Technology

2009-06-01

USACE 2008c)) on June 3, 1992 that “effectively precludes the future use of expanded polystyrene unless it is encased in an approved protective coating...punctured. Closed cell (extruded) expanded polystyrene of good quality and manufac- tured for marine use will be required. Lesser quality foam bead flota...Forest Service (USFS) (USFS 2008) – “Open cell Expanded Polystyrene Foam (EPS) has an open structure that easily lets water into its interior. It

Quantitative Determination of Wax Contamination in Polystyrene HIPE Foam Using Solid-State NMR

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cluff, Kyle James; Goodwin, Lynne Alese; Hamilton, Christopher Eric

Differences in molecular mobility between polystyrene foam and Brij-78 wax results in vast differences in the 1H nuclear magnetic resonance (NMR) linewidth. This allows for the convenient determination of wax content in the polystyrene foam components of inertial confinement fusion targets via solid-state NMR. Lastly, contamination levels as low as 0.1% are easily recognized and quantified, and the detection limit is calculated to be 0.02% even when only 32 transients are recorded.

Quantitative Determination of Wax Contamination in Polystyrene HIPE Foam Using Solid-State NMR

DOE PAGES

Cluff, Kyle James; Goodwin, Lynne Alese; Hamilton, Christopher Eric; ...

2017-11-29

Differences in molecular mobility between polystyrene foam and Brij-78 wax results in vast differences in the 1H nuclear magnetic resonance (NMR) linewidth. This allows for the convenient determination of wax content in the polystyrene foam components of inertial confinement fusion targets via solid-state NMR. Lastly, contamination levels as low as 0.1% are easily recognized and quantified, and the detection limit is calculated to be 0.02% even when only 32 transients are recorded.

Thermodynamic and Kinetic Behavior of the Polystyrene/Poly(vinyl methyl ether) Blend as Studied by Excimer Fluorescence.

DTIC Science & Technology

1986-01-02

AD-A±63 895 THERMODYNAMIC AND KINETIC BEHAVIOR OF THE / POLYSTYRENE/POLY(YINYL METHYL E..(U) STANFORD UNIY CALIFDEPT OF CHEMICAL ENGINEERING C N...Polystyrene/Poly(vinyl methyl ether) Blend 7. DEcFRMN 81 toOR 30USptE8 00~ as Studied by Excimer Fluorescence 6 EFRIGOG EOTNME *AUTHOR() a. CONTRACT OR GRANT...werea fondoare ihemoriisof * ~ Ex e sp fluodecositionsdu to deud Gen e and hoog Pinus Florsneis shownhase migrationprocSECURITY CLASIFICTIO OFd

Lipase polystyrene giant amphiphiles.

PubMed

Velonia, Kelly; Rowan, Alan E; Nolte, Roeland J M

2002-04-24

A new type of giant amphiphilic molecule has been synthesized by covalently connecting a lipase enzyme headgroup to a maleimide-functionalized polystyrene tail (40 repeat units). The resulting biohybrid forms catalytic micellar rods in water.

Influence of annealing temperature on optical properties of the photonic-crystal structures obtained by self-organization of colloidal microspheres of polystyrene and silica

NASA Astrophysics Data System (ADS)

Mikhnev, L. V.; Bondarenko, E. A.; Chapura, O. M.; Skomorokhov, A. A.; Kravtsov, A. A.

2018-01-01

The influence of annealing temperature on the transmission spectra of photonic crystals composed of polystyrene and silicon dioxide microspheres was studied. It was found that annealing of photonic crystals based on polystyrene and silica leads to a shift in the photonic band gap to the short-wavelength region. Based on the results of optical studies, the dependences of the structural parameters of the obtained opal-like crystals on annealing temperature were obtained. In the case of polystyrene photonic crystals, the displacement of the photonic band gap is observed in a narrow temperature range above the glass transition temperature. For SiO2 photonic crystals, it was found that the process of microspheres sintering is complex and involves three stages of structural modification.

On the analysis of activation energy of PS 35000 in various solvents

NASA Astrophysics Data System (ADS)

Padmanaban, R.; Venkatramanan, K.

2015-08-01

Polymer is a macromolecule, composed of many repeated subunits. Polystyrene is a polymer of styrene. Polystyrene has very low impact strength. Polystyrene generally leads to lower tensile strength, crystal grades being stiff and brittle. It is used to construct clamshell packs, cookie trays, cups, forks, spoons, cushioning materials for packaging, disposable medical devices, egg cartons, fast food containers, lids, lunch boxes, meat trays and also used in civil construction (concrete form-work or weight reduction on foundations). In the present study an attempt has been made to compute the viscosity of Polystyrene (PS 35000) in toluene and benzene in different concentrations (0.5%, 1.0%, 1.5%, 2.0% & 2.5%) at different temperatures (303 K, 308 K, 313 K & 318 K). From these experimental data the activation energy is calculated and the effect of solvent is analysed.

The mechanical and physical properties of concrete containing polystyrene beads as aggregate and palm oil fuel ash as cement replacement material

NASA Astrophysics Data System (ADS)

Adnan, Suraya Hani; Abadalla, Musab Alfatih Salim; Jamellodin, Zalipah

2017-10-01

One of the disadvantages of normal concrete is the high self-weight of the concrete. Density of the normal concrete is in the range of 2200 kg/m3 to 2600 kg/ m3. This heavy self-weight make it as an uneconomical structural material. Advantages of expended polystyrene beads in lightweight concrete is its low in density which can reduce the dead load (self-weight) Improper disposal of the large quantity of palm oil fuel ash which has been produced may contribute to environmental problem in future. In this study, an alternative of using palm oil fuel ash as a cement replacement material is to improve the properties of lightweight concrete. The tests conducted in this study were slump test, compression strength, splitting tensile and water absorption test. These samples were cured under water curing condition for 7, 28 and 56 days before testing. Eight types of mixtures were cast based on percentage (25%, 50%) of polystyrene beads replacement for control samples and (25%, 50%) of polystyrene beads by different ratio 10%, 15%, and 20% replacement of palm oil fuel ash, respectively. Samples with 25% polystyrene beads and 10% palm oil fuel ash obtained the highest compressive strength which is 16.8 MPa, and the splitting tensile strength is 1.57 MPa. The water absorption for samples 25%, 50% polystyrene and 20% palm oil fuel ash is 3.89% and 4.67%, respectively which is lower compared to control samples.

Surface-enhanced Raman spectroscopy substrate based on Ag-coated self-assembled polystyrene spheres

NASA Astrophysics Data System (ADS)

Mikac, Lara; Ivanda, Mile; Gotić, Marijan; Janicki, Vesna; Zorc, Hrvoje; Janči, Tibor; Vidaček, Sanja

2017-10-01

The silver (Ag) films were deposited on the monodispersed polystyrene spheres that were drop-coated on hydrophilic glass substrates in order to form a self-assembled 2D monolayer. Thus prepared Ag films over polystyrene nanospheres (AgFONs) were used to record the surface-enhanced Raman scattering (SERS) spectra of rhodamine 6G (R6G) and pyridine (λex = 514.5 nm). AgFONs were prepared by depositing 120, 180 and 240 nm thick Ag layer on the 1000 nm polystyrene spheres and 80, 120, 160 and 200 nm thick Ag layer on the 350 nm spheres as well as on their mixture (350 + 1000 nm). The silver was deposited by electron beam evaporation technique. The best enhancement of the Raman signal for both test molecules was obtained using 180 nm Ag film deposited on the 1000 nm spheres and using 80 nm Ag film deposited on the 350 nm polystyrene spheres. The lowest detectable concentrations of R6G and pyridine were 10-9 mol L-1 and 1.2 × 10-3 mol L-1, respectively. This study has shown that AgFONs could be regarded as good and reproducible SERS substrate for analytical detection of various organic molecules.

Hydrophobic Polystyrene Passivation Layer for Simultaneously Improved Efficiency and Stability in Perovskite Solar Cells.

PubMed

Li, Minghua; Yan, Xiaoqin; Kang, Zhuo; Huan, Yahuan; Li, Yong; Zhang, Ruxiao; Zhang, Yue

2018-06-06

The major restraint for the commercialization of the high-performance hybrid metal halide perovskite solar cells is the long-term stability, especially at the infirm interface between the perovskite film and organic charge-transfer layer. Recently, engineering the interface between the perovskite and spiro-OMeTAD becomes an effective strategy to simultaneously improve the efficiency and stability in the perovskite solar cells. In this work, we demonstrated that introducing an interfacial polystyrene layer between the perovskite film and spiro-OMeTAD layer can effectively improve the perovskite solar cells photovoltaic performance. The inserted polystyrene layer can passivate the interface traps and defects effectively and decrease the nonradiative recombination, leading to enhanced photoluminescence intensity and carrier lifetime, without compromising the carrier extraction and transfer. Under the optimized condition, the perovskite solar cells with the polystyrene layer achieve an enhanced average power efficiency of about 19.61% (20.46% of the best efficiency) from about 17.63% with negligible current density-voltage hysteresis. Moreover, the optimized perovskite solar cells with the hydrophobic polystyrene layer can maintain about 85% initial efficiency after 2 months storage in open air conditions without encapsulation.

Microporous polystyrene particles for selective carbon dioxide capture.

PubMed

Kaliva, Maria; Armatas, Gerasimos S; Vamvakaki, Maria

2012-02-07

This study presents the synthesis of microporous polystyrene particles and the potential use of these materials in CO(2) capture for biogas purification. Highly cross-linked polystyrene particles are synthesized by the emulsion copolymerization of styrene (St) and divinylbenzene (DVB) in water. The cross-link density of the polymer is varied by altering the St/DVB molar ratio. The size and the morphology of the particles are characterized by scanning and transmission electron microscopy. Following supercritical point drying with carbon dioxide or lyophilization from benzene, the polystyrene nanoparticles exhibit a significant surface area and permanent microporosity. The dried particles comprising 35 mol % St and 65 mol % DVB possess the largest surface area, ∼205 m(2)/g measured by Brunauer-Emmett-Teller and ∼185 m(2)/g measured by the Dubinin-Radushkevich method, and a total pore volume of 1.10 cm(3)/g. Low pressure measurements suggest that the microporous polystyrene particles exhibit a good separation performance of CO(2) over CH(4), with separation factors in the range of ∼7-13 (268 K, CO(2)/CH(4) = 5/95 gas mixture), which renders them attractive candidates for use in gas separation processes.

Polystyrene Prints

ERIC Educational Resources Information Center

O'Malley, William

1969-01-01

Discussed are the exciting advantages and possibilities of using polystyrene trays found in meat packaging for printmaking. Among them are ease of use, low cost and quick availability of materials, beautiful textural effects. Procedures are explained for various age levels. (BF)

Sorption of tetracycline antibiotics on hyper-crosslinked polystyrene from aqueous and aqueous-organic media

NASA Astrophysics Data System (ADS)

Udalova, A. Yu.; Dmitrienko, S. G.; Apyari, V. V.

2015-06-01

The sorption of tetracycline, oxytetracycline, chlortetracycline, and doxycycline on hyper-cross-linked polystyrene from aqueous and aqueous-organic solutions is studied under static and dynamic conditions in order to extend the range of the sorbents suitable for sorption isolation and the preconcentration of tetracycline antibiotics. Features of tetracycline sorption depending on the acidity of a solution and the nature and concentration of the compounds are explained. It is shown that hyper-crosslinked polystyrene can be used for the group sorption preconcentration of these compounds.

Study of morphological changes in scattering and optically anisotropic medium through correlation images

NASA Astrophysics Data System (ADS)

Jain, Neha; Shukla, Prashant; Singh, Jai

2018-05-01

Correlation images are very useful in determining the morphological changes. We have investigated the correlation image analysis on depolarization and retardance matrices of polystyrene and gelatine samples respectively. We observed that that correlation images have a potential to show a significant variation with change in the concentration of samples (polystyrene and gelatine). For polystyrene microspheres the correlation value decreases with increasing scattering coefficient. In gelatine samples the correlation also decreases with sample concentration. This variation in correlation for retardance shows the change in a birefringence property of gelatine solution.

A High-Performance Recycling Solution for Polystyrene Achieved by the Synthesis of Renewable Poly(thioether) Networks Derived from d-Limonene

PubMed Central

Nash, Landon D.; Rodriguez, Jennifer N.; Lonnecker, Alexander T.; Raymond, Jeffery E.; Wilson, Thomas S.; Wooley, Karen L.; Maitland, Duncan J.

2014-01-01

Nanocomposite polymers have been prepared using a new sustainable materials synthesis process in which d-Limonene functions simultaneously both as a solvent for recycling polystyrene (PS) waste and as a monomer that undergoes UV-catalyzed thiol-ene polymerization reactions with polythiol co-monomers to afford polymeric products comprised of precipitated PS phases dispersed throughout elastomeric poly(thioether) networks. These blended networks exhibit mechanical properties that greatly exceed those of either polystyrene or the poly(thioether) network homopolymers alone. PMID:24249666

Synthesis of polystyrene coated SiC nanowires as fillers in a polyurethane matrix for electromechanical conversion.

PubMed

Rybak, Andrzej; Warde, Micheline; Beyou, Emmanuel; Chaumont, Philippe; Bechelany, Mikhael; Brioude, Arnaud; Toury, Bérangère; Cornu, David; Miele, Philippe; Guiffard, Benoit; Seveyrat, Laurence; Guyomar, Daniel

2010-04-09

Grafting of polystyrene (PS) from silica coating of silicon carbide nanowires (SiCNWs) has been performed by a two-step nitroxide mediated free radical polymerization (NMP) of styrene. First, an alkoxyamine based on N-tert-butyl-N-(1-diethylphosphono-2,2-dimethylpropyl) nitroxide (DEPN) was covalently attached onto NWs through free surface silanol groups. To immobilize the alkoxyamine initiator on the silica surface, alkoxylamine was formed in situ by the simultaneous reaction of polymerizable acryloxy propyl trimethoxysilane (APTMS), azobis isobutyronitrile (AIBN), and DEPN, which was used as a radical trap. Polystyrene chains with controlled molecular weights and narrow polydispersity were then grown from the alkoxyamine-functionalized NWs surface in the presence of a 'free' sacrificial styrylDEPN alkoxyamine. Both the initiator and polystyrene chains were characterized by FTIR and (13)C solid-state NMR and quantified by TGA. Ensuing nanocomposites were characterized by FEG-SEM, TEM and Raman spectroscopy. EDX analysis performed on functionalized nanowires during FEG-SEM analysis also gave evidence of grafting by a strong increase in the average C/Si atomic ratio. Incorporation of 2 wt% NWs into the polyurethane (PU) matrix has been carried out to prepare homogeneous nanocomposite films. The electric field induced thickness strain response has been investigated for the polystyrene-grafted silica coated SiC NWs (PU-SiC@SiO(2)@PS) nanocomposites and compared to pure polyurethane film and PU-SiC@SiO(2) nanocomposite without polystyrene grafting. At a moderate electric field of 10 V microm(-1), SiC@SiO(2)@PS loading increased the strain level of pure PU by a factor of 2.2. This improvement came partially due to polystyrene grafting since PU-SiC@SiO(2) films showed only a 1.7 times increase. The observed higher strain response of these nanocomposites makes them very attractive for micro-electromechanical applications.

A generalized method for alignment of block copolymer films: solvent vapor annealing with soft shear.

PubMed

Qiang, Zhe; Zhang, Yuanzhong; Groff, Jesse A; Cavicchi, Kevin A; Vogt, Bryan D

2014-08-28

One of the key issues associated with the utilization of block copolymer (BCP) thin films in nanoscience and nanotechnology is control of their alignment and orientation over macroscopic dimensions. We have recently reported a method, solvent vapor annealing with soft shear (SVA-SS), for fabricating unidirectional alignment of cylindrical nanostructures. This method is a simple extension of the common SVA process by adhering a flat, crosslinked poly(dimethylsiloxane) (PDMS) pad to the BCP thin film. The impact of processing parameters, including annealing time, solvent removal rate and the physical properties of the PDMS pad, on the quality of alignment quantified by the Herman's orientational factor (S) is systematically examined for a model system of polystyrene-block-polyisoprene-block-polystyrene (SIS). As annealing time increases, the SIS morphology transitions from isotropic rods to highly aligned cylinders. Decreasing the rate of solvent removal, which impacts the shear rate imposed by the contraction of the PDMS, improves the orientation factor of the cylindrical domains; this suggests the nanostructure alignment is primarily induced by contraction of PDMS during solvent removal. Moreover, the physical properties of the PDMS controlled by the crosslink density impact the orientation factor by tuning its swelling extent during SVA-SS and elastic modulus. Decreasing the PDMS crosslink density increases S; this effect appears to be primarily driven by the changes in the solubility of the SVA-SS solvent in the PDMS. With this understanding of the critical processing parameters, SVA-SS has been successfully applied to align a wide variety of BCPs including polystyrene-block-polybutadiene-block-polystyrene (SBS), polystyrene-block-poly(N,N-dimethyl-n-octadecylammonium p-styrenesulfonate) (PS-b-PSS-DMODA), polystyrene-block-polydimethylsiloxane (PS-b-PDMS) and polystyrene-block-poly(2-vinlypyridine) (PS-b-P2VP). These results suggest that SVA-SS is a generalizable method for the alignment of BCP thin films.

Translations on USSR Industrial Affairs, Number 441

DTIC Science & Technology

1978-08-03

manufacture of furniture, briefcases, various haberdashery items, cases for electronic instruments, movie and still cameras. Expanded polystyrene paper...per year of expanded polystyrene paper. 3024 CSO: 1821 13 KHIMVOLOKNO PLANT RECONSTRUCTION DISCUSSED Moscow MATERIAL1 NO-TEKHimJHESKOYE

Variable Lysozyme Transport Dynamics on Oxidatively Functionalized Polystyrene Films.

PubMed

Moringo, Nicholas A; Shen, Hao; Tauzin, Lawrence J; Wang, Wenxiao; Bishop, Logan D C; Landes, Christy F

2017-10-17

Tuning protein adsorption dynamics at polymeric interfaces is of great interest to many biomedical and material applications. Functionalization of polymer surfaces is a common method to introduce application-specific surface chemistries to a polymer interface. In this work, single-molecule fluorescence microscopy is utilized to determine the adsorption dynamics of lysozyme, a well-studied antibacterial protein, at the interface of polystyrene oxidized via UV exposure and oxygen plasma and functionalized by ligand grafting to produce varying degrees of surface hydrophilicity, surface roughness, and induced oxygen content. Single-molecule tracking indicates lysozyme loading capacities, and surface mobility at the polymer interface is hindered as a result of all functionalization techniques. Adsorption dynamics of lysozyme depend on the extent and the specificity of the oxygen functionalities introduced to the polystyrene surface. Hindered adsorption and mobility are dominated by hydrophobic effects attributed to water hydration layer formation at the functionalized polystyrene surfaces.

Narrowly peaked forward light scattering on particulate media: II. Angular spreading of light scattered by polystyrene microspheres

NASA Astrophysics Data System (ADS)

Turcu, Ioan; Bratfalean, Radu; Neamtu, Silvia

2008-07-01

The adequacy of the effective phase function (EPF) used to describe the light scattered at small angles was tested on aqueous suspensions of polystyrene microspheres. Angular resolved light scattering measurements were performed on two types of latex suspension, which contained polystyrene spheres of 3 µm and 5 µm diameters, respectively. The experimental data were fitted with two EPF approximants. If the polystyrene spheres are at least 3 µm in diameter the quasi-ballistic light scattering process can be described relatively well by the EPF in a small angular range centered in the forward direction. The forward light scattering by macroscopic samples containing microspheres can be modeled relatively well if the true Mie single particle scattering phase function is replaced by a simpler Henyey-Greenstein dependence having the same width at half-height as the first scattering lobe.

Spectroscopic study of the charge-transfer complexes TiCl4/styrene and TiCl4/polystyrene

NASA Astrophysics Data System (ADS)

Gonçalves, Norberto S.; Noda, Lúcia. K.

2017-10-01

In this work, solutions of TiCl4/styrene and TiCl4/polystyrene charge-transfer complexes in CHCl3 or CDCl3 were investigated by UV-vis, resonance Raman and 1H NMR spectroscopies in order to study their molecular and electronic structures. Both show a yellow colour due to absorption in the 400 nm region, related to a charge-transfer transition. In Raman spectra, as the excitation approaches the resonance region, the primary enhancement of aromatic ring modes was mainly observed, rather than intensification of the vinylic double-bond stretch. Under the experimental conditions it was observed that formation of polystyrene takes place, as showed by 1H NMR spectra, and the most significant interaction occurs at the aromatic ring, as supported by the results from interaction of TiCl4 with polystyrene, as indicated by the charge-transfer band and resonant intensification of the aromatic ring modes.

The effect of gamma irradiation on chemical, morphology and optical properties of polystyrene nanosphere at various exposure time

NASA Astrophysics Data System (ADS)

Alhaji Yabagi, Jibrin; Isah Kimpa, Mohammed; Nmayaya Muhammad, Muhammad; Rashid, Saiful Bin; Zaidi, Embong; Arif Agam, Mohd

2018-01-01

Irradiation of polymers causes structural, chemical and the optical properties changes. Polystyrene nanosphere was drop coated to substrates and the gamma irradiation was carried out in a Cesium-137 (Cs-137) source chamber at different time (1-5 hours) with constant dose of 30 kGy. Fourier transformation infrared spectroscopy (FTIR) and Raman spectroscopy were employed to characterize the chemical properties of irradiated polystyrene while Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM) were used to study the surface morphological changes of the samples. The optical energy band gaps of the thin films were investigated and studied using transmittance and absorbance measurements. The results obtained revealed that as irradiation time increases the optical properties changes and polystyrene gradually undergoes crystal to carbonaceous from its amorphous state. The average particles diameter and roughness of the samples decreases with increasing irradiation time.

Synthesis and characterization of magnetic and non-magnetic core-shell polyepoxide micrometer-sized particles of narrow size distribution.

PubMed

Omer-Mizrahi, Melany; Margel, Shlomo

2009-01-15

Core polystyrene microspheres of narrow size distribution were prepared by dispersion polymerization of styrene in a mixture of ethanol and 2-methoxy ethanol. Uniform polyglycidyl methacrylate/polystyrene core-shell micrometer-sized particles were prepared by emulsion polymerization at 73 degrees C of glycidyl methacrylate in the presence of the core polystyrene microspheres. Core-shell particles with different properties (size, surface morphology and composition) have been prepared by changing various parameters belonging to the above seeded emulsion polymerization process, e.g., volumes of the monomer glycidyl methacrylate and the crosslinker monomer ethylene glycol dimethacrylate. Magnetic Fe(3)O(4)/polyglycidyl methacrylate/polystyrene micrometer-sized particles were prepared by coating the former core-shell particles with magnetite nanoparticles via a nucleation and growth mechanism. Characterization of the various particles has been accomplished by routine methods such as light microscopy, SEM, FTIR, BET and magnetic measurements.

Human plasma fibrinogen adsorption and platelet adhesion to polystyrene.

PubMed

Tsai, W B; Grunkemeier, J M; Horbett, T A

1999-02-01

The purpose of this study was to further investigate the role of fibrinogen adsorbed from plasma in mediating platelet adhesion to polymeric biomaterials. Polystyrene was used as a model hydrophobic polymer; i.e., we expected that the role of fibrinogen in platelet adhesion to polystyrene would be representative of other hydrophobic polymers. Platelet adhesion was compared to both the amount and conformation of adsorbed fibrinogen. The strategy was to compare platelet adhesion to surfaces preadsorbed with normal, afibrinogenemic, and fibrinogen-replenished afibrinogenemic plasmas. Platelet adhesion was determined by the lactate dehydrogenase (LDH) method, which was found to be closely correlated with adhesion of 111In-labeled platelets. Fibrinogen adsorption from afibrinogenemic plasma to polystyrene (Immulon I(R)) was low and <10 ng/cm2. Platelet adhesion was absent on surfaces preadsorbed with afibrinogenemic plasma when the residual fibrinogen was low enough (<60 microg/mL). Platelet adhesion was restored on polystyrene preadsorbed with fibrinogen-replenished afibrinogenemic plasma. Addition of even small, subnormal concentrations of fibrinogen to afibrinogenemic plasma greatly increased platelet adhesion. In addition, surface-bound fibrinogen's ability to mediate platelet adhesion was different, depending on the plasma concentration from which fibrinogen was adsorbed. These differences correlated with changes in the binding of a monoclonal antibody that binds to the Aalpha chain RGDS (572-575), suggesting alteration in the conformation or orientation of the adsorbed fibrinogen. Platelet adhesion to polystyrene preadsorbed with blood plasma thus appears to be a strongly bivariate function of adsorbed fibrinogen, responsive to both low amounts and altered states of the adsorbed molecule. Copyright 1999 John Wiley & Sons, Inc.

40 CFR 60.561 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... recovered for reuse in the process, off-site purification or treatment, or sale, at the time the process... polypropylene, polyethylene, polystyrene, (general purpose, crystal, or expandable) or poly(ethylene... production of polypropylene, polyethylene, polystyrene, (general purpose, crystal, or expandable), or poly...

40 CFR 60.561 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... recovered for reuse in the process, off-site purification or treatment, or sale, at the time the process... polypropylene, polyethylene, polystyrene, (general purpose, crystal, or expandable) or poly(ethylene... production of polypropylene, polyethylene, polystyrene, (general purpose, crystal, or expandable), or poly...

Investigating the Role of Surface Materials and Three Dimensional Architecture on In Vitro Differentiation of Porcine Monocyte-Derived Dendritic Cells

PubMed Central

Hartmann, Sofie Bruun; Mohanty, Soumyaranjan; Skovgaard, Kerstin; Brogaard, Louise; Flagstad, Frederikke Bjergvang; Emnéus, Jenny; Wolff, Anders; Summerfield, Artur; Jungersen, Gregers

2016-01-01

In vitro generation of dendritic-like cells through differentiation of peripheral blood monocytes is typically done using two-dimensional polystyrene culture plates. In the process of optimising cell culture techniques, engineers have developed fluidic micro-devises usually manufactured in materials other than polystyrene and applying three-dimensional structures more similar to the in vivo environment. Polydimethylsiloxane (PDMS) is an often used polymer for lab-on-a-chip devices but not much is known about the effect of changing the culture surface material from polystyrene to PDMS. In the present study the differentiation of porcine monocytes to monocyte-derived dendritic cells (moDCs) was investigated using CD172apos pig blood monocytes stimulated with GM-CSF and IL-4. Monocytes were cultured on surfaces made of two- and three-dimensional polystyrene as well as two- and three-dimensional PDMS and carbonised three-dimensional PDMS. Cells cultured conventionally (on two-dimensional polystyrene) differentiated into moDCs as expected. Interestingly, gene expression of a wide range of cytokines, chemokines, and pattern recognition receptors was influenced by culture surface material and architecture. Distinct clustering of cells, based on similar expression patterns of 46 genes of interest, was seen for cells isolated from two- and three-dimensional polystyrene as well as two- and three-dimensional PDMS. Changing the material from polystyrene to PDMS resulted in cells with expression patterns usually associated with macrophage expression (upregulation of CD163 and downregulation of CD1a, FLT3, LAMP3 and BATF3). However, this was purely based on gene expression level, and no functional assays were included in this study which would be necessary in order to classify the cells as being macrophages. When changing to three-dimensional culture the cells became increasingly activated in terms of IL6, IL8, IL10 and CCR5 gene expression. Further stimulation with LPS resulted in a slight increase in the expression of maturation markers (SLA-DRB1, CD86 and CD40) as well as cytokines (IL6, IL8, IL10 and IL23A) but the influence of the surfaces was unchanged. These findings highlights future challenges of combining and comparing data generated from microfluidic cell culture-devices made using alternative materials to data generated using conventional polystyrene plates used by most laboratories today. PMID:27362493

Investigating the Role of Surface Materials and Three Dimensional Architecture on In Vitro Differentiation of Porcine Monocyte-Derived Dendritic Cells.

PubMed

Hartmann, Sofie Bruun; Mohanty, Soumyaranjan; Skovgaard, Kerstin; Brogaard, Louise; Flagstad, Frederikke Bjergvang; Emnéus, Jenny; Wolff, Anders; Summerfield, Artur; Jungersen, Gregers

2016-01-01

In vitro generation of dendritic-like cells through differentiation of peripheral blood monocytes is typically done using two-dimensional polystyrene culture plates. In the process of optimising cell culture techniques, engineers have developed fluidic micro-devises usually manufactured in materials other than polystyrene and applying three-dimensional structures more similar to the in vivo environment. Polydimethylsiloxane (PDMS) is an often used polymer for lab-on-a-chip devices but not much is known about the effect of changing the culture surface material from polystyrene to PDMS. In the present study the differentiation of porcine monocytes to monocyte-derived dendritic cells (moDCs) was investigated using CD172apos pig blood monocytes stimulated with GM-CSF and IL-4. Monocytes were cultured on surfaces made of two- and three-dimensional polystyrene as well as two- and three-dimensional PDMS and carbonised three-dimensional PDMS. Cells cultured conventionally (on two-dimensional polystyrene) differentiated into moDCs as expected. Interestingly, gene expression of a wide range of cytokines, chemokines, and pattern recognition receptors was influenced by culture surface material and architecture. Distinct clustering of cells, based on similar expression patterns of 46 genes of interest, was seen for cells isolated from two- and three-dimensional polystyrene as well as two- and three-dimensional PDMS. Changing the material from polystyrene to PDMS resulted in cells with expression patterns usually associated with macrophage expression (upregulation of CD163 and downregulation of CD1a, FLT3, LAMP3 and BATF3). However, this was purely based on gene expression level, and no functional assays were included in this study which would be necessary in order to classify the cells as being macrophages. When changing to three-dimensional culture the cells became increasingly activated in terms of IL6, IL8, IL10 and CCR5 gene expression. Further stimulation with LPS resulted in a slight increase in the expression of maturation markers (SLA-DRB1, CD86 and CD40) as well as cytokines (IL6, IL8, IL10 and IL23A) but the influence of the surfaces was unchanged. These findings highlights future challenges of combining and comparing data generated from microfluidic cell culture-devices made using alternative materials to data generated using conventional polystyrene plates used by most laboratories today.

Development of a Water Soluble Foam Packaging Material

DTIC Science & Technology

1975-01-01

Material, Expanded Polystyrene , Looae-Fill Bulk and standard properties were established. Additional investigations conducted on the loose-fill samples...mechanical properties when tested as described in Federal Specification PPP-O-1683; Cushioning Material, Expanded Polystyrene , Loose-Fill Bulk. The following

Measuring thermal conductivity of polystyrene nanowires using the dual-cantilever technique.

PubMed

Canetta, Carlo; Guo, Samuel; Narayanaswamy, Arvind

2014-10-01

Thermal conductance measurements are performed on individual polystyrene nanowires using a novel measurement technique in which the wires are suspended between two bi-material microcantilever sensors. The nanowires are fabricated via electrospinning process. Thermal conductivity of the nanowire samples is found to be between 6.6 and 14.4 W m(-1) K(-1) depending on sample, a significant increase above typical bulk conductivity values for polystyrene. The high strain rates characteristic of electrospinning are believed to lead to alignment of molecular polymer chains, and hence the increase in thermal conductivity, along the axis of the nanowire.

Oxygen Plasma Effect on QCM Sensor Coated Polystyrene Film

NASA Astrophysics Data System (ADS)

Khusnah, N. F.; Sakti, S. P.; Santjojo, D. J. D. H.

2018-05-01

Hydrophobicity property of polystyrene (PS) thin film is one of the essential factors to be considered in the development of quartz crystal microbalance (QCM) biosensor using polystyrene as matrix layer. Many methods were developed to improve the immobilization rate of the biomolecule on the sensor surface without affecting the QCM essential works. Surface modification of the sensor surface aims to modify the physical and or chemical property of the surface. A straightforward method, the fast, environmentally-friendly, and low-cost solution to modify the sensor surface coated with polystyrene film is using oxygen plasma. In this experiment, the polystyrene film was spin-coated on both surface of QCM electrodes and then heated at 100 °C. The specimen is then placed for 5 min long in a chamber filled with oxygen plasma generated by 2 MHz RF-DC high-density plasma system. The relationship between DC-bias used and the changes in morphology properties of the coated film was characterized by Topography Measurement System (TMS) and Contact Angle Measurement. The electrical characteristic of QCM was also characterized using Impedance Analyzer. It was revealed that the contact angle of oxygen plasma treated film is changed and depicted the hydrophobic character. Also, there is an increasing resonance frequency of the sensor after oxygen plasma treatment indicates an etching mechanism occurs during plasma treatment.

Factors affecting the oral uptake and translocation of polystyrene nanoparticles: histological and analytical evidence.

PubMed

Florence, A T; Hillery, A M; Hussain, N; Jani, P U

1995-01-01

Quantitative and qualitative evidence from our laboratories on the absorption and translocation of polystyrene latex nanoparticles both by histological (qualitative) and analytical measurement of levels of polystyrene (quantitative) is briefly reviewed in this paper. We have previously compared the uptake of nonionized polystyrene latex ranging in size from 50nm to 3 microns, and made some comparisons of uptake between carboxylated microspheres and nonionic systems, showing the lower uptake of the former through the lymphoid tissue of the gastrointestinal tract. Size is a key parameter, uptake increasing with decreasing particle diameter. Early evidence suggested that uptake is by way of the Peyer's patches and other elements of the gut associated lymphoid tissue (GALT). Adsorption of hydrophilic block-copolymers onto polystyrene markedly reduces the uptake by intestinal GALT. Modification of the surface with specific ligands such as by covalent attachment of tomato lectin molecules has indicated widespread uptake by non-GALT tissues, following their binding to and internalisation by enterocytes. The ability to decrease and increase uptake is clear evidence of a phenomenon which has the potential for further control to allow it to be exploited fully for drug or vaccine delivery. The evidence to date with nanoparticles as carriers systems for labile drugs such as proteins by the oral route remains to be substantiated.

Nanofiltration membranes of poly(styrene- co-chloro-methylstyrene)- grafted-DGEBA reinforced with gold and polystyrene nanoparticles for water purification

NASA Astrophysics Data System (ADS)

Kausar, Ayesha; Siddiq, Muhammad

2017-06-01

The matrix material for nanofiltration membranes was prepared through chemical grafting of poly(styrene- co-chloromethylstyrene) (PSCMS) to DGEBA using hexamethylenediamine as linker. The phase inversion technique was used to form PSCMS- g-DGEBA membranes. This effort also involves the designing of gold nanoparticles and its composite nanoparticles with polystyrene microspheres as matrix reinforcement. The nanoporous morphology was observed at lower filler content and there was formation of nanopattern at increased nanofiller content. The tensile strength was improved from 32.5 to 35.2 MPa with the increase in AuNPs-PSNPs loading from 0.1 to 1 wt%. The glass transition temperature was also enhanced from 132 to 159 °C. The membrane properties were measured via nanofiltration set-up. Higher pure water permeation flux, recovery, and salt rejection were measured for novel membranes. PSCMS- g-DGEBA/AuNPs-PSNPs membrane with 1 wt% loading showed flux of 2.01 mL cm-2 min-1 and salt rejection ratio of 70.4 %. Efficiency of the gold/polystyrene nanoparticles reinforced membranes for the removal of Hg2+ and Pb2 was found to be 99 %. Novel hybrid membranes possess fine characteristics to be utilized in industrial water treatment units.

75 FR 9438 - Americas Styrenics, LLC-Marietta Plant a Subsidiary of Americas Styrenics, LLLC Formerly Known as...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-02

... workers of the subject firm. The workers are engaged in the production of styrene monomer and polystyrene... increased customer imports of styrene monomer and polystyrene pellets. The amended notice applicable to TA-W...

Identification and measurement of intermolecular interaction in polyester/polystyrene blends by FTIR-photoacoustic spectrometry

USDA-ARS?s Scientific Manuscript database

Fourier transform infrared photoacoustic spectrometry was used to reveal and identify n-p type intermolecular interaction formed in plastic comprising binary blends of polystyrene and a biodegradable polymer, either polylactic acid, polycaprolactone or poly(tetramethyleneadipate-co-terephthalate)....

Exercise Balikatan 2012 Technology Insertion Quicklook Report

DTIC Science & Technology

2012-05-15

expanded polystyrene panels covered with a thin layer of cement, sand, fiberglass, and other additives. A permanent 200 sq ft building with windows... Expanded Polystyrene 1.5# density pre-cut panels and GFRC -Glass Fiber Reinforced Concrete Structural coating (Fiberglass Mesh, Portland Cement, Silica

Differences in the adsorption behaviour of poly(ethylene oxide) copolymers onto model polystyrene nanoparticles assessed by isothermal titration microcalorimetry correspond to the biological differences.

PubMed

Stolnik, S; Heald, C R; Garnett, M G; Illum, L; Davis, S S

2005-01-01

The adsorption behaviour of a tetrafunctional copolymer of poly (ethylene oxide)-poly (propylene oxide) ethylene diamine (commercially available as Poloxamine 908) and a diblock copolymer of poly (lactic acid)-poly (ethylene oxide) (PLA/PEG 2:5) onto a model colloidal drug carrier (156 nm sized polystyrene latex) is described. The adsorption isotherm, hydrodynamic thickness of the adsorbed layers and enthalpy of the adsorption were assessed. The close similarity in the conformation of the poly (ethylene oxide) (PEO) chains (molecular weight 5,000 Da) in the adsorbed layers of these two copolymers was demonstrated by combining the adsorption data with the adsorbed layer thickness data. In contrast, the results from isothermal titration microcalorimetry indicated a distinct difference in the interaction of the copolymers with the polystyrene colloid surface. Poloxamine 908 adsorption to polystyrene nanoparticles is dominated by an endothermic heat effect, whereas, PLA/PEG 2:5 adsorption is entirely an exothermic process. This difference in adsorption behaviour could provide an explanation for differences in the biodistribution of Poloxamine 908 and PLA/PEG 2:5 coated polystyrene nanoparticles observed in previous studies. A comparison with the interaction enthalpy for several other PEO-containing copolymers onto the same polystyrene colloid was made. The results demonstrate the importance of the nature of the anchoring moiety on the interaction of the adsorbing copolymer with the colloid surface. An endothermic contribution is found when an adsorbing molecule contains a poly (propylene oxide) (PPO) moiety (e.g. Poloxamine 908), whilst the adsorption is exothermic (i.e. enthalpy driven) for PEO copolymers with polylactide (PLA/PEG 2:5) or alkyl moieties.

Interactions of proteins in human plasma with modified polystyrene resins.

PubMed

Boisson-Vidal, C; Jozefonvicz, J; Brash, J L

1991-01-01

Investigations are reported on the composition of protein layers adsorbed from plasma to various modified polystyrene resins. As well as polystyrene itself, polystyrene bearing sulfonate groups in the benzene rings, and polystyrene sulfonate in which the sulfonate groups were converted to amino acid sulfamide, were investigated. Some of these resins were shown in previous work to have anticoagulant properties. To study the adsorption of proteins from plasma, the resins were exposed to citrate anticoagulated human plasma for 3 h. Adsorbed proteins were then eluted sequentially by 1M Tris buffer and 4% SDS solution, and examined by SDS-PAGE. The gel patterns were similar on all resins except polystyrene. From the MWs of the gel bands, the major protein component appeared to be fibrinogen. Smaller amounts of plasminogen, transferrin, albumin, and IgG were also present. In addition, Ouchterlony immunoassay of the eluates from one resin gave positive identification of complement C3, fibronectin, IgG, and IgM. Many other minor gel bands remain unidentified. A consistent finding for all resins was the presence of plasmin-type fibrinogen degradation products though the amounts varied with resin type. It is concluded from this (and from experiments showing FDP formation when fibrinogen was absorbed to the resins, from buffer containing a trace of plasminogen) that the functional groups in these materials promote the adsorption of plasminogen and its activation to a plasmin-like molecule. It appears from the substantial quantities of fibrinogen adsorbed to these materials after 3 h exposure to plasma that the Vroman effect (giving transient adsorption of fibrinogen) is not operative on these materials. It is hypothesized that specific interactions occur between fibrinogen and sulfonate groups.

COAL/POLYMER COPROCESSING WITH EFFICIENT USE OF HYDROGEN

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dr. Linda J. Broadbelt; Matthew J. DeWitt; Hsi-Wu Wong

2000-09-30

The final project period was devoted to investigating the binary mixture pyrolysis of polypropylene and polystyrene. Their interactions were assessed in order to provide a baseline for experiments with multicomponent mixtures of polymers with coal. Pyrolysis of polypropylene, polystyrene and their binary mixture was investigated at temperatures of 350 C and 420 C with reaction times from 1 to 180 minutes. Two different loadings, 10 mg and 20 mg, were studied for neat polypropylene and polystyrene to assess the effect of total pressure on product yields and selectivities. For neat pyrolysis of polypropylene, total conversion was much higher at 420more » C, and no significant effect of loading on the total conversion was observed. Four classes of products, alkanes, alkenes, dienes, and aromatic compounds, were observed, and their distribution was explained by a typical free radical mechanism. For neat polystyrene pyrolysis, conversion reached approximately 75% at 350 C, while at 420 C the conversion reached a maximum around 90% at 10 minutes and decreased at longer times because of condensation reactions. The selectivities to major products were slightly different for the two different loadings due to the effect of total reaction pressure on secondary reactions. For binary mixture pyrolysis, the overall conversion was higher than the average of the two neat cases. The conversion of polystyrene remained the same, but a significant enhancement in the polypropylene conversion was observed. This suggests that the less reactive polypropylene was initiated by polystyrene-derived radicals. These results are summarized in detail in an attached manuscript that is currently in preparation. The other results obtained during the lifetime of this grant are documented in the set of attached manuscripts.« less

Adsorption and covalent binding of fibrinogen as a method for probing the chemical composition of poly(styrene/α-tert-butoxy-ω-vinylbenzyl-polyglycidol) microsphere surfaces.

PubMed

Gosecka, Monika; Chehimi, Mohamed M; Basinska, Teresa; Slomkowski, Stanislaw; Makowski, Tomasz

2017-12-01

We investigated the distribution of polyglycidol and polystyrene on the surface of poly(styrene/α-tert-butoxy-ω-vinylbenzyl-polyglycidol) microspheres (random distribution or segregated into hydrophilic and hydrophobic patches), using fibrinogen (Fb) as a macromolecular probe. The fibrinogen was adsorbed or covalently attached to the surface of the poly(styrene-co-α-tert-butoxy-ω-vinylbenzyl-polyglycidol) (P(S/PGLy)) microspheres. The P(S/PGLy) particles were prepared by emulsion copolymerization of styrene and α-tert-butoxy-ω-vinylbenzyl-polyglycidol (PGLy) macromonomer initiated with potassium persulfate. The polymerizations yielded P(S/PGLy) particles with various surface fractions of polyglycidol, depending on the amount of added macromonomer and the addition process. In some syntheses, the entire macromonomer amount was added once at the beginning of the polymerization, while in others, the macromonomer was added gradually after the formation of particle seeds from pure polystyrene. XPS studies revealed that the fraction of polyglycidol in the interfacial layer of the microspheres was larger when the entire amount of macromonomer was added at the beginning of the polymerization than when it was added after formation of the polystyrene seeds. Studies of fibrinogen adsorption provided the first evidence of segregation of the hydrophobic (polystyrene) and hydrophilic (polyglycidol) components at the surface of the composite P(S/PGLy) microspheres into patches. The hydrophobic patches are composed mainly of polystyrene. However, they also contain a small amount of polyglycidol chains, making the adsorption of fibrinogen weaker than the adsorption onto the pure polystyrene. Studies of covalent immobilization of fibrinogen on the microspheres via 1,3,5-trichlorotriazine confirmed these findings. Copyright © 2017 Elsevier B.V. All rights reserved.

Packaging produced from natural fibers and mycelium: Optimizing biomass blends to meet performance specifications

USDA-ARS?s Scientific Manuscript database

Polystyrene is non-biodegradable and has environmental issues associated with its disposal. A replacement for polystyrene that is biodegradable, environmentally friendly, and has similar performance characteristics is of interest to many ecologically minded companies and consumers. This study utiliz...

Development and Evaluation of Elastomeric Materials for Geothermal Applications

NASA Technical Reports Server (NTRS)

Mueller, W. A.; Kalfayan, S. H.; Reilly, W. W.; Yavrouian, A. H.; Mosesman, I. D.; Ingham, J. D.

1979-01-01

A material was formulated having about 250-350 psi tensile strength and 30-80 percent elongation at 260 C for at least 24 hours in simulated brine. The relationship between these laboratory test results and sealing performance in actual or simulated test conditions is not entirely clear; however, it is believed that no conventional formation or casing packer design is likely to perform well using these materials. The synthetic effort focused on high temperature block copolymers and development of curable polystyrene. Procedures were worked out for synthesizing these new materials. Initial results with heat-cured unfilled polystyrene 'gum' at 260 C indicate a tensile strength of about 50 psi. Cast films of the first sample of polyphenyl quinoxaline-polystyrene block copolymer, which has 'graft-block' structure consisting of a polystyrene chain with pendant polyphenyl quinoxaline groups, show elastomeric behavior in the required temperature range. Its tensile strength and elongation at 260 C were 220-350 psi and 18-36 percent, respectively. All of these materials also showed satisfactory hydrolytic stability.

Low-cost silver capped polystyrene nanotube arrays as super-hydrophobic substrates for SERS applications.

PubMed

Lovera, Pierre; Creedon, Niamh; Alatawi, Hanan; Mitchell, Micki; Burke, Micheal; Quinn, Aidan J; O'Riordan, Alan

2014-05-02

In this paper, we describe the fabrication, simulation and characterization of dense arrays of freestanding silver capped polystyrene nanotubes, and demonstrate their suitability for surface enhanced Raman scattering (SERS) applications. Substrates are fabricated in a rapid, low-cost and scalable way by melt wetting of polystyrene (PS) in an anodized alumina (AAO) template, followed by silver evaporation. Scanning electron microscopy reveals that substrates are composed of a dense array of freestanding polystyrene nanotubes topped by silver nanocaps. SERS characterization of the substrates, employing a monolayer of 4-aminothiophenol (4-ABT) as a model molecule, exhibits an enhancement factor of ∼1.6 × 10(6), in agreement with 3D finite difference time domain simulations. Contact angle measurements of the substrates revealed super-hydrophobic properties, allowing pre-concentration of target analyte into a small volume. These super-hydrophobic properties of the samples are taken advantage of for sensitive detection of the organic pollutant crystal violet, with detection down to ∼400 ppt in a 2 μl aliquot demonstrated.

Enhanced Stability and Bioconjugation of Photo-cross-linked Polystyrene-Shell, Au-Core Nanoparticles

PubMed Central

Chen, Ying; Cho, Juhee; Young, Alexi; Taton, T. Andrew

2008-01-01

Encapsulating Au nanoparticles within a shell of photo-cross-linked block copolymer surfactant dramatically improves the physical and chemical stability of the nanoparticles, particularly when they are applied as bioconjugates. Photo-cross-linkable block copolymer amphiphiles [polystyrene-co-poly(4-vinyl benzophenone)]-block-poly(acrylic acid) [(PS-co-PVBP)-b-PAA] and [poly(styrene)-co-poly(4-vinyl benzophenone)]-block-poly(ethylene oxide) [(PS-co-PVBP)-b-PEO] were assembled around Au nanoparticles ranging from 12 nm to 108 nm in diameter. UV irradiation cross-linked the PVBP groups on the polymer to yield particles that withstood extremes of temperature, ionic strength, and chemical etching. Streptavidin was attached to [PS-co-PVBP]-b-PAA coated particles using the same noncovalent and covalent conjugation protocols used to bind biomolecules to divinylbenzene-crosslinked polystyrene microspheres. We expect that these particles will be useful as plasmonic, highly light-scattering and light-absorbing analogs to fluorescently labeled polystyrene nanospheres. PMID:17530871

Application of image recognition algorithms for statistical description of nano- and microstructured surfaces

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mărăscu, V.; Dinescu, G.; Faculty of Physics, University of Bucharest, 405 Atomistilor Street, Bucharest-Magurele

In this paper we propose a statistical approach for describing the self-assembling of sub-micronic polystyrene beads on silicon surfaces, as well as the evolution of surface topography due to plasma treatments. Algorithms for image recognition are used in conjunction with Scanning Electron Microscopy (SEM) imaging of surfaces. In a first step, greyscale images of the surface covered by the polystyrene beads are obtained. Further, an adaptive thresholding method was applied for obtaining binary images. The next step consisted in automatic identification of polystyrene beads dimensions, by using Hough transform algorithm, according to beads radius. In order to analyze the uniformitymore » of the self–assembled polystyrene beads, the squared modulus of 2-dimensional Fast Fourier Transform (2- D FFT) was applied. By combining these algorithms we obtain a powerful and fast statistical tool for analysis of micro and nanomaterials with aspect features regularly distributed on surface upon SEM examination.« less

Polymer thin film as coating layer to prevent corrosion of metal/metal oxide film

NASA Astrophysics Data System (ADS)

Sarkar, Suman; Kundu, Sarathi

2018-04-01

Thin film of polymer is used as coating layer and the corrosion of metal/metal oxide layer is studied with the variation of the thickness of the coating layer. The thin layer of polystyrene is fabricated using spin coating method on copper oxide (CuO) film which is deposited on glass substrate using DC magnetron sputtering technique. Thickness of the polystyrene and the CuO layers are determined using X-ray reflectivity (XRR) technique. CuO thin films coated with the polystyrene layer are exposed to acetic acid (2.5 v/v% aqueous CH3COOH solution) environments and are subsequently analyzed using UV-Vis spectroscopy and atomic force microscopy (AFM). Surface morphology of the film before and after interaction with the acidic environment is determined using AFM. Results obtained from the XRR and UV-Vis spectroscopy confirm that the thin film of polystyrene acts as an anticorrosion coating layer and the strength of the coating depends upon the polymer layer thickness at a constant acid concentration.

Temperature and molecular-weight dependences of acoustic behaviors of polystyrene studied using Brillouin spectroscopy

NASA Astrophysics Data System (ADS)

Oh, Soo Han; Lee, Byoung Wan; Ko, Jae-Hyeon; Lee, Hyeonju; Park, Jaehoon; Ko, Young Ho; Kim, Kwang Joo

2017-04-01

The acoustic properties of three polystyrene polymers with different molecular weights were investigated as a function of temperature by using Brillouin light scattering. The longitudinal sound velocity showed a change in the slope, which depended on the molecular weight, at the glass transition temperature. The absorption coefficient exhibited a maximum above the glass transition temperature, and the maximum temperature became higher as the molecular weight was increased. Comparison with previous acoustic studies on polystyrene indicate that a substantial frequency dispersion caused by strong coupling between the longitudinal acoustic waves and the segmental motions exists in the high-temperature range.

Engineering of Surface Functionality onto Polystyrene Microcarriers for the Attachment and Growth of Human Endothelial Cells

NASA Astrophysics Data System (ADS)

Xiong, Gordon M.; Foord, John S.; Griffiths, Jon-Paul; Parker, Emily M.; Moloney, Mark G.; Choong, Cleo

2014-08-01

This work reports the effects of introducing diverse chemical functionalities onto the surface of polystyrene microcarrier beads on their ability to function as injectable cell carriers. Cellular adhesion and proliferation, as well as cellular outgrowths from microcarrier surfaces, using human umbilical vein endothelial cells (HUVECs), were examined in detail. It was observed that initial cell adhesion appeared to be most significantly decreased by hydrophobicity, whilst cell proliferation appeared to be improved in most chemical functional groups over unmodified polystyrene. Overall, our study highlights the importance of surface chemistry in directing the growth and function of human endothelial cells.

Block Copolymer Membranes for Biofuel Purification

NASA Astrophysics Data System (ADS)

Evren Ozcam, Ali; Balsara, Nitash

2012-02-01

Purification of biofuels such as ethanol is a matter of considerable concern as they are produced in complex multicomponent fermentation broths. Our objective is to design pervaporation membranes for concentrating ethanol from dilute aqueous mixtures. Polystyrene-b-polydimethylsiloxane-b-polystyrene block copolymers were synthesized by anionic polymerization. The polydimethylsiloxane domains provide ethanol-transporting pathways, while the polystyrene domains provide structural integrity for the membrane. The morphology of the membranes is governed by the composition of the block copolymer while the size of the domains is governed by the molecular weight of the block copolymer. Pervaporation data as a function of these two parameters will be presented.

Raman spectroscopy investigation and improved knowledge on industrial cation-exchange membranes involved in electrodialysis process

NASA Astrophysics Data System (ADS)

Chaouki, M.; Huguet, P.; Bribes, J.-L.

1996-06-01

Raman spectra of three specific, industrial, cation-exchange membranes (CEMs) have shown the existence of an extra vibrational band. The relative intensity of this band is different in each membrane spectrum recorded. Chlorosulfonation of polymeric ethylenetrifluoroethylene (ETFE) film grafted with polystyrene chains is used to obtain these CEMs involved in the electrodialysis process. A Raman study of the above reaction has been undertaken and has shown that non-sulfonated polystyrene rings give rise to this extra vibrational band. Different behavior of CEMs synthesized under similar conditions can be explained by a variable amount of non-sulfonated polystyrene rings contained in these materials.

Oral exposure to polystyrene nanoparticles effects iron absorption

USDA-ARS?s Scientific Manuscript database

The use of engineered nanoparticles in food and pharmaceuticals is expected to increase, but the impact of chronic oral exposure to nanoparticles on human health remains unknown. Here, we show that chronic and acute oral exposure to polystyrene nanoparticles can influence iron uptake and iron trans...

Integration of Multiple Components in Polystyrene-based Microfluidic Devices Part 1: Fabrication and Characterization

PubMed Central

Johnson, Alicia S.; Anderson, Kari B.; Halpin, Stephen T.; Kirkpatrick, Douglas C.; Spence, Dana M.; Martin, R. Scott

2012-01-01

In Part I of a two-part series, we describe a simple, and inexpensive approach to fabricate polystyrene devices that is based upon melting polystyrene (from either a Petri dish or powder form) against PDMS molds or around electrode materials. The ability to incorporate microchannels in polystyrene and integrate the resulting device with standard laboratory equipment such as an optical plate reader for analyte readout and micropipettors for fluid propulsion is first described. A simple approach for sample and reagent delivery to the device channels using a standard, multi-channel micropipette and a PDMS-based injection block is detailed. Integration of the microfluidic device with these off-chip functions (sample delivery and readout) enables high throughput screens and analyses. An approach to fabricate polystyrene-based devices with embedded electrodes is also demonstrated, thereby enabling the integration of microchip electrophoresis with electrochemical detection through the use of a palladium electrode (for a decoupler) and carbon-fiber bundle (for detection). The device was sealed against a PDMS-based microchannel and used for the electrophoretic separation and amperometric detection of dopamine, epinephrine, catechol, and 3,4-dihydroxyphenylacetic acid. Finally, these devices were compared against PDMS-based microchips in terms of their optical transparency and absorption of an anti-platelet drug, clopidogrel. Part I of this series lays the foundation for Part II, where these devices were utilized for various on-chip cellular analysis. PMID:23120747

A study of the effect of polystyrene sulfonation on the performance of terephthaloyl chloride-dihydroxydiphenyl sulfone copolymer/polystyrene system

NASA Astrophysics Data System (ADS)

Kahraman, R.; Kahn, K. A.; Ali, S. A.; Hamid, S. H.; Sahin, A. Z.

1998-12-01

Thermal, morphological, and mechanical properties of composites of a liquid crystalline copolymer (LCP) poly(terephthaloyl chloride)-co-(p,p’-dihydroxydiphenyl sulfone) with polystyrene (PS) and sulfonated polystyrene (SPS) are presented and discussed. Sulfonation of polystyrene was expected to improve the interfacial adhesion by introducing hydrogen bonding in the LCP/PS system. The degree of sulfonation was 11 %. The incompatibility (lack of proper interfacial adhesion) of the LCP/PS system resulted in sharp decrease in the composite tensile strength with LCP addition. The performance of the system did not change when processed at a higher temperature (270 °C instead of 225 °C). While a composite plate of 25% LCP/PS could not be fabricated, it was possible for LCP/SPS (processed at 215 °C), indicating some improvement in interfacial bonding by sulfonation. Sulfonation of PS resulted in fracture with some degree of plastic deformation for pure SPS matrix and also the LCP/SPS system with the lowest LCP content (1 wt%), whereas plastic deformation was not observed for PS used as received. The strength of the LCP/SPS system also decreased with increase in LCP content, indicating that 11% sulfonation is not sufficient to introduce significant compatibility, but it was not as dramatic as that for LCP/PS. The performance of the LCP/SPS system was not affected significantly by heat treatment at the process temperature.

Expansion of Bone Marrow Mesenchymal Stromal Cells in Perfused 3D Ceramic Scaffolds Enhances In Vivo Bone Formation.

PubMed

Hoch, Allison I; Duhr, Ralph; Di Maggio, Nunzia; Mehrkens, Arne; Jakob, Marcel; Wendt, David

2017-12-01

Bone marrow-derived mesenchymal stromal cells (BMSC), when expanded directly within 3D ceramic scaffolds in perfusion bioreactors, more reproducibly form bone when implanted in vivo as compared to conventional expansion on 2D polystyrene dishes/flasks. Since the bioreactor-based expansion on 3D ceramic scaffolds encompasses multiple aspects that are inherently different from expansion on 2D polystyrene, we aimed to decouple the effects of specific parameters among these two model systems. We assessed the effects of the: 1) 3D scaffold vs. 2D surface; 2) ceramic vs. polystyrene materials; and 3) BMSC niche established within the ceramic pores during in vitro culture, on subsequent in vivo bone formation. While BMSC expanded on 3D polystyrene scaffolds in the bioreactor could maintain their in vivo osteogenic potential, results were similar as BMSC expanded in monolayer on 2D polystyrene, suggesting little influence of the scaffold 3D environment. Bone formation was most reproducible when BMSC are expanded on 3D ceramic, highlighting the influence of the ceramic substrate. The presence of a pre-formed niche within the scaffold pores had negligible effects on the in vivo bone formation. The results of this study allow a greater understanding of the parameters required for perfusion bioreactor-based manufacturing of osteogenic grafts for clinical applications. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Functionally Charged Polystyrene Particles Activate Immortalized Mouse Microglia (BV2): Cellular and Genomic Response

EPA Science Inventory

The effect of particle surface charge on the biological activation of immortalized mouse microglia (BV2) was examined. Same size (~850-950 nm) spherical polystyrene microparticles (SPM) with net negative (carboxyl, COOH-) or positive (dimethyl amino, CH₃)₂

Nitrogen dioxide detection

DOEpatents

Sinha, Dipen N.; Agnew, Stephen F.; Christensen, William H.

1993-01-01

Method and apparatus for detecting the presence of gaseous nitrogen dioxide and determining the amount of gas which is present. Though polystyrene is normally an insulator, it becomes electrically conductive in the presence of nitrogen dioxide. Conductance or resistance of a polystyrene sensing element is related to the concentration of nitrogen dioxide at the sensing element.

Scattering by Spheroidal and Rough Particles.

DTIC Science & Technology

1982-12-01

expanded polystyrene beads(Sincl.air-Koppers DylJ.te F 40) in the weight proportion 0.025 to 1.0, and molding the homogeaeous mixture in cement molds...stacking 7 expanded polystyrene (Sinclair-Koppers Dylite F 40) cylinders. The second group(/030 series) is prepared by coating the similar stack by

Specifications and Other Standardization Documents Involving Cellular Plastics (Plastic Foams), Cushioning and Related Materials

DTIC Science & Technology

1976-07-01

FOR MEDICAL MATERIAL REQUIRING CONTROLLED TEMPERATURE RANGES 258 PPP-C-1683(1) 8135 69 10 Oct 73 CUSHIONING MATERIAL, EXPANDED POLYSTYRENE LOOSE FILL...Liquid immersion effect on properties of elastoaeric vulcanizates - 45 Lead deflection characteristics - 264 Loose-fill expanded polystyrene - 25f

Master curve captures the effect of domain morphology on ethanol pervaporation through block copolymer membranes

USDA-ARS?s Scientific Manuscript database

We report on the effect of changing nanoscale morphology on pervaporation of ethanol/water mixtures through block copolymer membranes. Experiments were conducted using polystyrene-b-polybutadiene-b-polystyrene (SBS) copolymers with polybutadiene (PB) as the ethanol transporting block, using an 8 wt%...

Design and evaluation of expanded polystyrene geofoam embankments for the I-15 reconstruction project, Salt Lake City, Utah.

DOT National Transportation Integrated Search

2012-10-01

The report discusses the design and 10-year performance evaluations of Expanded Polystyrene (EPS) Geofoam embankment constructed for the I-15 Reconstruction Project in Salt Lake City, Utah between 1998 and 2002. It contains methods to evaluate the al...

Preparation of polystyrene microspheres for laser velocimetry in wind tunnels

NASA Technical Reports Server (NTRS)

Nichols, Cecil E., Jr.

1987-01-01

Laser Velocimetry (L/V) had made great strides in replacing intrusive devices for wind tunnel flow measurements. The weakness of the L/V has not been the L/V itself, but proper size seeding particles having known drag characteristics. For many Langley Wind Tunnel applications commercial polystyrene latex microspheres suspended in ethanol, injected through a fluid nozzle provides excellent seeding but was not used due to the high cost. This paper provides the instructions, procedures, and formulations for producing polystyrene latex monodisperse microspheres of 0.6, 1.0, 1.7, 2.0, and 2.7 micron diameters. These are presently being used at Langley Research Center as L/V seeding particles.

Preparation of Electrically Conductive Polystyrene/Carbon Nanofiber Nanocomposite Films

ERIC Educational Resources Information Center

Sun, Luyi; O'Reilly, Jonathan Y.; Tien, Chi-Wei; Sue, Hung-Jue

2008-01-01

A simple and effective approach to prepare conductive polystyrene/carbon nanofiber (PS/CNF) nanocomposite films via a solution dispersion method is presented. Inexpensive CNF, which has a structure similar to multi-walled carbon nanotubes, is chosen as a nanofiller in this experiment to achieve conductivity in PS films. A good dispersion is…

Synthesis of selenium nano-composite (t-Se@PS) by surface initiated atom transfer radical polymerization.

PubMed

Wang, Michael C P; Gates, Byron D

2012-09-04

Selenium nanostructures, which are otherwise susceptible to oxidative damage, were encapsulated with a thin layer of polystyrene. The thin layer of polystyrene was grafted onto the surfaces of selenium by a surface initiated atom transfer radical polymerization reaction. These encapsulated nanostructures demonstrate an enhanced resistance towards corrosion.

The Incredible Shrinking Cup Lab: An Investigation of the Effect of Depth and Water Pressure on Polystyrene

EPA Science Inventory

This activity familiarizes students with the effects of increased depth on pressure and volume. Students will determine the volume of polystyrene cups before and after they are submerged to differing depths in the ocean and the Laurentian Great Lakes. Students will also calculate...

21 CFR 178.3130 - Antistatic and/or anti-fogging agents in food-packaging materials.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Antistatic and/or anti-fogging agents in food..., fresh fruits, and fresh vegetables. Alpha-(Carboxymethyl)-omega-(tetradecyloxy)polyoxyethylene) For use... at levels not to exceed 3.0 percent by weight of polystyrene or rubber-modified polystyrene complying...

21 CFR 178.3130 - Antistatic and/or anti-fogging agents in food-packaging materials.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Antistatic and/or anti-fogging agents in food..., fresh fruits, and fresh vegetables. Alpha-(Carboxymethyl)-omega-(tetradecyloxy)polyoxyethylene) For use... at levels not to exceed 3.0 percent by weight of polystyrene or rubber-modified polystyrene complying...

Evaluation of High Performance Aircrew Helmets and Oxygen Masks

DTIC Science & Technology

1982-10-01

site. This is achieved because 1.6 cm of expanded polystyrene is inserted in this area. It is concludeC that, while only the DH 41-4D helmets provide...Plastic Liner (TPL). Impact protection is provided by a rigid expanded polystyrene interliner between the helmet shell and the TPL. Four of these liners

Building Technology Forecast and Evaluation (BTFE). Volume 2. Evaluation of Two Structural Systems

DTIC Science & Technology

1990-11-01

insulative foam ( expanded polystyrene ) strips between each truss. The assembly is held together with 14-gauge wires welded to the trusses on 2-in. centers...structural load bearing qualities expanded polystyrene . No taping and mudding. Ar. ~J~ .wplrtpd( at each irllnfrnPllo Tile I hin- set or float over

Standoff Acoustic Shear Wave Imaging Using LFM Chirps

DTIC Science & Technology

2011-03-21

is typically ignored due to the large wavelengths in biological tissue. For the test material presented in this paper ( expanded polystyrene foam...inhomogeneous sound speed, 1( )c x , for a 2.5×5×7 cm steel parallelepiped embedded in a 15×23×23 cm block of expanded polystyrene foam, which

Application of a constant hole volume Sanchez-Lacombe equation of state to mixtures relevant to polymeric foaming.

PubMed

von Konigslow, Kier; Park, Chul B; Thompson, Russell B

2018-06-06

A variant of the Sanchez-Lacombe equation of state is applied to several polymers, blowing agents, and saturated mixtures of interest to the polymer foaming industry. These are low-density polyethylene-carbon dioxide and polylactide-carbon dioxide saturated mixtures as well as polystyrene-carbon dioxide-dimethyl ether and polystyrene-carbon dioxide-nitrogen ternary saturated mixtures. Good agreement is achieved between theoretically predicted and experimentally determined solubilities, both for binary and ternary mixtures. Acceptable agreement with swelling ratios is found with no free parameters. Up-to-date pure component Sanchez-Lacombe characteristic parameters are provided for carbon dioxide, dimethyl ether, low-density polyethylene, nitrogen, polylactide, linear and branched polypropylene, and polystyrene. Pure fluid low-density polyethylene and nitrogen parameters exhibit more moderate success while still providing acceptable quantitative estimations. Mixture estimations are found to have more moderate success where pure components are not as well represented. The Sanchez-Lacombe equation of state is found to correctly predict the anomalous reversal of solubility temperature dependence for low critical point fluids through the observation of this behaviour in polystyrene nitrogen mixtures.

Water-stable diblock polystyrene-block-poly(2-vinyl pyridine) and diblock polystyrene-block-poly(methyl methacrylate) cylindrical patterned surfaces inhibit settlement of zoospores of the green alga Ulva.

PubMed

Grozea, Claudia M; Gunari, Nikhil; Finlay, John A; Grozea, Daniel; Callow, Maureen E; Callow, James A; Lu, Zheng-Hong; Walker, Gilbert C

2009-04-13

Nanopatterned surfaces with hydrophobic and hydrophilic domains were produced using the diblock copolymer polystyrene-block-poly(2-vinyl pyridine) (PS-b-P2VP) and polystyrene-block-poly(methyl methacrylate) (PS-b-PMMA). The PS-b-P2VP diblock copolymer, mixed with the cross-linker benzophenone and spin-coated onto silicon wafers, showed self-assembled cylindrical structures, which were retained after UV treatment for cross-linking. The thin films displayed cylindrical domains after immersion in water. This study shows that pattern retention in water is possible for a long period of time, at least for two weeks in pure water and three weeks in artificial seawater. The PS-b-PMMA diblock showed self-assembled cylindrical structures. PS-b-P2VP and PS-b-PMMA cylindrical patterned surfaces showed reduced settlement of zoospores of the green alga Ulva compared to unpatterned surfaces. The copolymers were investigated using atomic force microscopy and X-ray photoelectron spectroscopy.

Ignition of expandable polystyrene foam by a hot particle: an experimental and numerical study.

PubMed

Wang, Supan; Chen, Haixiang; Liu, Naian

2015-01-01

Many serious fires have occurred in recent years due to the ignition of external building insulation materials by hot metallic particles. This work studied the ignition of expandable polystyrene foam by hot metallic particles experimentally and numerically. In each experiment, a spherical steel particle was heated to a high temperature (within 1173-1373K) and then dropped to the surface of an expandable polystyrene foam block. The particles used in experiments ranged from 3mm to 7 mm in radius. The observed results for ignition were categorized into two types: "flaming ignition" and "no ignition", and the flaming ignition limit was determined by statistical analysis. According to the experimental observations, a numerical model was proposed, taking into account the reactant consumption and volatiles convection of expandable polystyrene decomposition in air. Three regimes, no ignition, unstable ignition and stable ignition, were identified, and two critical particle temperatures for separating the three regimes were determined. Comparison with the experimental data shows that the model can predict the range of critical ignition temperatures reasonably well. Copyright © 2014 Elsevier B.V. All rights reserved.

Fungal biodegradation of lignopolystyrene graft copolymers. [Pleurotus ostreatus; Phanerochaete chrysosporium; Trametes versicolor; Gloeophyllum trabeum

DOE Office of Scientific and Technical Information (OSTI.GOV)

Milstein, O.; Gersonde, R.; Huttermann, A.

1992-10-01

White rot basidiomycetes were able to biodegrade styrene (1-phenylethene) graft copolymers of lignin containing different proportions of lignin and polystyrene (poly(1-phenylethylene)). The biodegradation tests were run on lignin-styrene copolymerization products which contained 10.3, 32.2, and 50.4{percent} (wt/wt) lignin. The polymer samples were incubated with the white rot fungi Pleurotus ostreatus, Phanerochaete chrysosporium, and Trametes versicolor and the brown rot fungus Gloeophyllum trabeum. White rot fungi degraded the plastic samples at a rate which increased with increasing lignin content in the copolymer sample. Both polystyrene and lignin components of the copolymer were readily degraded. Polystyrene pellets were not degradable in thesemore » tests. Degradation was verified for both incubated and control samples by weight loss, quantitative UV spectrophotometric analysis of both lignin and styrene residues, scanning electron microscopy of the plastic surface, and the presence of enzymes active in degradation during incubation. Brown rot fungus did not affect any of the plastics. White rot fungi produced and secreted oxidative enzymes associated with lignin degradation in liquid media during incubation with lignin-polystyrene copolymer.« less

Mechanisms of the self-organization of star-shaped polymers with a varied structure of branching center based on fullerene C{sub 60} in solutions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lebedev, V. T., E-mail: vlebedev@pnpi.spb.ru; Toeroek, Gy.; Vinogradova, L. V.

The self-organization of star-shaped polymers in toluene has been studied by small-angle neutron scattering. Polystyrene stars with a mono-C{sub 60} branching center are ordered into globular clusters ({approx}1700 nm in diameter), whereas stars with a double (C{sub 60}-C{sub 60}) center are ordered into anisotropic structures (superchains), which are linked (depending on the concentration) into triads (chain clusters {approx}2500 nm in diameter). On the contrary, heteroarm polystyrene and poly-2-vinylpyridine stars with a C{sub 60} center are weakly associated into dimers. Moderately polar stars with arms composed of polystyrene and diblock copolymer (poly-2-vinylpyridine-poly-tret-butyl methacrylate) form short chains composed of four macromolecules, whilemore » stars of higher polarity based on polystyrene and poly-tret-butyl methacrylate form clusters containing {approx}12 macromolecules {approx}50 nm in diameter. Thus, by varying the structure of the center and the arm polarity, one can control the modes of star structuring.« less

Photothermal therapy of Lewis lung carcinoma in mice using gold nanoshells on carboxylated polystyrene spheres

NASA Astrophysics Data System (ADS)

Liu, Huiyu; Chen, Dong; Tang, Fangqiong; Du, Gangjun; Li, Linlin; Meng, Xianwei; Liang, Wei; Zhang, Yangde; Teng, Xu; Li, Yi

2008-11-01

A new approach towards the design of gold nanoshells on carboxylated polystyrene spheres (GNCPSs) is reported here. Gold nanoshells were self-assembled on the surface of carboxylated polystyrene spheres by a seed growth method. Chitosan (CHI) was used as a functional agent of carboxylated polystyrene spheres for attaching gold seeds. The surface plasmon resonance (SPR) peak of GNCPSs can be tuned, greatly redshifted, over a broad spectral range including the near-infrared (NIR) wavelength region, which provides maximal penetration of light through tissue. Irradiation of GNCPSs at their peak extinction coefficient results in the conversion of light to heat energy that produces a local rise in temperature. Our study revealed that the Lewis lung carcinoma (LLC) in mice treated with GNCPSs exposed to a low dose of NIR light (808 nm, 4 W cm-2) induced irreversible tissue damage. The tumor volumes of the treatment group by GNCPSs were significantly lower than those of control groups, with an average inhibition rate over 55% (P<0.005). This study proves that GNCPSs are promising in plasmonic photothermal tumor therapy.

Pyrolysis of polystyrene waste in the presence of activated carbon in conventional and microwave heating using modified thermocouple.

PubMed

Prathiba, R; Shruthi, M; Miranda, Lima Rose

2018-06-01

Pyrolysis process was experimented using two types of heating source, namely conventional and microwave. Polystyrene (PS) plastic waste was used as feedstock in a batch reactor for both the conventional (slow pyrolysis) and microwave pyrolysis. The effect of activated carbon to polystyrene ratio on (i) yield of oil, gas and residues (ii) reaction temperature (iii) reaction time were studied. Quality of oil from pyrolysis of polystyrene were assessed for the possible applicability in fuel production. Microwave power of 450 W and polymer to activated carbon ratio of 10:1, resulted in the highest oil yield of 93.04 wt.% with a higher heating value of 45 MJ kg -1 and a kinematic viscosity of 2.7 cSt. Microwave heating when compared to conventional heating method, exhibits a reaction temperature and time of 330 °C in 5.5 min, whereas in conventional heating system it was 418 °C in 60 min. The gas chromatography-mass spectrometry analysis of liquid oil from microwave pyrolysis predominantly yields alkenes of 8.44 wt.%, α-methyl styrene 0.96 wt.%, condensed ring aromatics 23.21 wt.% and benzene derivatives 26.77 wt.% when the polystyrene to activated carbon ratio was 10:1. Significant factor of using microwave heating is the amount of energy converted (kWh) is lesser than conventional heating. Copyright © 2018 Elsevier Ltd. All rights reserved.

Fast synthesis, formation mechanism, and control of shell thickness of CuS–polystyrene core–shell microspheres

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhao, Li-min, E-mail: zhaolimin@lcu.ecu.cn; Shao, Xin; Yin, Yi-bin

2012-09-15

Graphical abstract: Core–shell structure PSt/CuS were prepared using polystyrene which were modified by 3-methacryloxypropyltrimethoxysilane as template. The coating thickness of CuS can be controlled by the amount of 3-methacryloxypropyltrimethoxysilane and the UV–vis absorption intensity of PSt/CuS composite also changed with the coating thickness of CuS. Highlights: ► Core–shell structure PSt/CuS were prepared using silanol-modified polystyrene microspheres as template. ► The coating thickness of core–shell structure PSt/CuS can be controlled by a simple method. ► The UV–vis absorption intensity of PSt/CuS composite also changed with the coating thickness of CuS. -- Abstract: The silanol-modified polystyrene microspheres were prepared through dispersion polymerization.more » Then copper sulfide particles were grown on silanol-modified polystyrene through sonochemical deposition in an aqueous bath containing copper acetate and sulfide, released through the hydrolysis of thioacetamide. The resulting particles were continuous and uniform as characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Fourier transform infrared, thermogravimetric analysis and UV–vis absorption spectroscopy were used to characterize the structure and properties of core–shell particles. The results showed the coating thickness of CuS shell can be controlled by the amount of silanol and the UV–vis absorption intensity of PSt/CuS composite also changed with the coating thickness of CuS.« less

Woodpecker Excavation and Use of Cavities in Polystyrene Snags

Treesearch

Richard N. Conner; Daniel Saenz

1996-01-01

We examined woodpecker excavation and use of artificial polystyrene snags in four forest types in eastern Texas for five years. Twenty-three of 47 artificial snags were used by Downy Woodpeckers (Picoides pubescens) for cavity excavation and subsequent nocturnal roosting; they did not use the artificial snags for nesting. Although six ather species of woodpeckers...

Field Study on Moisture Problems in Exterior Walls of Family Housing Units at Naval Air Station Pensacola, Florida.

DTIC Science & Technology

1984-02-01

exterior exposed concrete block walls with 2 inch (nominal) furring, 1 inch cellular board ( expanded polystyrene ) insulation, and gypsum board finish, as...furring strips, and new expanded polystyrene board thermal insu- lation and new gypsum board were installed. The purpose of the coating on the concrete

Measuring Thermal Performance of Building Envelopes: Nine Case Studies,

DTIC Science & Technology

1985-03-01

inch P/B = 11.36, present worth factor for an es- of expanded polystyrene insulation) to the build- calating series for a 15-year period ing exterior...inch of The one MCA building roof we measured was a expanded polystyrene at R-3.6 per inch. Where the cathedral system with a sloped built-up roofing

Recording dew gage

Treesearch

Merle G. Lloyd

1963-01-01

The instrument developed by Intermountain Forest and Range Experiment Station to record duration and amount of dew (fig. 1) consists of an expanded polystyrene block mounted on a balance, a clock-driven drum, and a pen geared from the balance to the drum. Changes in weight of the expanded polystyrene block as dew or rain is deposited are recorded on a chart mounted on...

Detection of Salmonella enterica serovar Enteritidis (SE) Antibodies in Serum Using A Polystyrene Bead/SE Flagella Agglutination Assay

USDA-ARS?s Scientific Manuscript database

Serologic screening of flocks can be an important method to detect Salmonella enteritidis (SE) infections but can be labor intensive or lack specificity. Our goal was to develop a rapid agglutination assay using SE flagella adsorbed to polystyrene beads as a simple, relatively specific test to dete...

DISPERSION POLYMERIZATION OF STYRENE IN SUPERCRITICAL CARBON DIOXIDE UTILIZING RANDOM COPOLYMERS INCLUDING FLUORINATED ACRYLATE FOR PREPARING MICRON-SIZE POLYSTYRENE PARTICLES. (R826115)

EPA Science Inventory

The dispersion polymerization of styrene in supercritical CO₂ utilizing CO₂-philic random copolymers was investigated. The resulting high yield of polystyrene particles in the micron-size range was formed using various random copolymers as stabilizers. The p...

The impact of fluorescent dyes on the performances of polystyrene-based plastic scintillators

NASA Astrophysics Data System (ADS)

Zhu, Jun; Deng, Cheng; Jiang, Huimin; Zheng, Zhanlong; Gong, Rui; Bi, Yutie; Zhang, Lin; Lin, Runxiong

2016-11-01

To investigate the influence of both the first luminescent additive and the wavelength-shifter on the performance of plastic scintillator, a series of polystyrene-based scintillator had been prepared by thermal polymerization. Three first luminescent additives (PPO, p-TP and b-PBD) and four wavelength-shifters (POPOP, Bis-MSB, Me-MSB and DPA) were added to the scintillators respectively. The comparison results showed that PPO and POPOP were the most adequate fluorescent dyes for the polystyrene-based plastic scintillator. Moreover, with the increase of the concentration of PPO and POPOP, the fluorescence intensity and light yield were increased firstly and then decreased. The plastic scintillator containing 2% PPO and 0.02% POPOP had the highest fluorescence intensity and light yield.

Thermal tuning the reversible optical band gap of self-assembled polystyrene photonic crystals

NASA Astrophysics Data System (ADS)

Vakili Tahami, S. H.; Pourmahdian, S.; Shirkavand Hadavand, B.; Azizi, Z. S.; Tehranchi, M. M.

2016-11-01

Nano-sized polymeric colloidal particles could undergo self-organization into three-dimensional structures to produce desired optical properties. In this research, a facile emulsifier-free emulsion polymerization method was employed to synthesize highly mono-disperse sub-micron polystyrene colloids. A high quality photonic crystal (PhC) structure was prepared by colloidal polystyrene. The reversible thermal tuning effect on photonic band gap position as well as the attenuation of the band gap was investigated in detail. The position of PBG can be tuned from 420 nm to 400 nm by varying the temperature of the PhC structure, reversibly. This reversible effect provides a reconfigurable PhC structure which could be used as thermo-responsive shape memory polymers.

Characterization of SWNT based Polystyrene Nanocomposites

NASA Astrophysics Data System (ADS)

Mitchell, Cynthia; Bahr, Jeffrey; Tour, James; Arepalli, Sivaram; Krishnamoorti, Ramanan

2003-03-01

Polystyrene nanocomposites with functionalized single walled carbon nanotubes (SWNTs), prepared by the in-situ generation and addition of organic diazonium compounds, were characterized using a range of structural and dynamic methods. These were contrasted to the properties of polystyrene composites prepared with unfunctionalized SWNTs at the same loadings. The functionalized nanocomposites demonstrated a percolated SWNT network structure at concentrations of 1 vol SWNT based composites at similar loadings of SWNT exhibited behavior comparable to that of the unfilled polymer. This formation of the SWNT network structure is because of the improved compatibility between the SWNTs and the polymer matrix due to the functionalization. Further structural evidence for the compatibility of the modified SWNTs and the polymer matrix will be discussed in the presentation.

Morphology and properties of wood-fiber reinforced blends of recycled polystyrene and polyethylene

Treesearch

John Simonsen; Timothy G. Rials

1996-01-01

Material properties of composites produced from recycled plastics and recycled wood fiber were compared. A blend of high-density polyethylene and polystyrene was used as a simulated mixed plastic. Stiffness was generally improved by the addition of fiber, as expected, but brittleness also increased. Pre-treatment of the wood filler with phenol-formaldehyde resins did...

Antimicrobial 3D Porous Scaffolds Prepared by Additive Manufacturing and Breath Figures.

PubMed

Vargas-Alfredo, Nelson; Dorronsoro, Ane; Cortajarena, Aitziber L; Rodríguez-Hernández, Juan

2017-10-25

We describe herein a novel strategy for the fabrication of efficient 3D printed antibacterial scaffolds. For this purpose, both the surface topography as well as the chemical composition of 3D scaffolds fabricated by additive manufacturing were modified. The scaffolds were fabricated by fused deposition modeling (FDM) using high-impact polystyrene (HIPS) filaments. The surface of the objects was then topographically modified providing materials with porous surfaces by means of the Breath Figures approach. The strategy involves the immersion of the scaffold in a polymer solution during a precise period of time. This approach permitted the modification of the pore size varying the immersion time as well as the solution concentration. Moreover, by using polymer blend solutions of polystyrene and polystyrene-b-poly(acrylic acid) (PS 23 -b-PAA 18 ) and a quaternized polystyrene-b-poly(dimethylaminoethyl methacrylate) (PS 42 -b-PDMAEMAQ 17 ), the scaffolds were simultaneously chemically modified. The surfaces were characterized by scanning electron microscopy and infrared spectroscopy. Finally, the biological response toward bacteria was explored. Porous surfaces prepared using quaternized PDMAEMA as well as those prepared using PAA confer antimicrobial activity to the films, i.e., were able to kill on contact Staphylococcus aureus employed as model bacteria.

Effect of surfactant on microstructure, surface hydrophilicity, mechanical and thermal properties of different multi-walled carbon nanotube/polystyrene composites

NASA Astrophysics Data System (ADS)

Li, Zhipeng; Zhang, Yanxia; Liang, Shaolei; Li, Guangfen

2018-05-01

We prepared nanocomposites of multi-walled carbon nanotube (MWCNT)/polystyrene via a solution casting method, where deionized water was used as coagulation bath. The influences of the type of MWCNTs and existence of surfactant on surface morphology, thermal properties and mechanical properties of MWCNT/polystyrene composites were extensively investigated. The pristine and two functionalized MWCNTs with the loading of 5 wt% were chosen for comparison. Both scanning electron microscopy and mercury intrusion porosimetry show that the composites without surfactant contain fewer pores and thus have higher bulk density, tensile strength, as well as low surface hydrophobicity. However, the porous structures within micro-range appear in all surfactant-treated composites, which decrease the bulk density and the tensile strength of their composites. This especially pronounced for the MWCNT-OH composite as the smallest pore size/highest porosity is found in the composites with loading of 5 wt% MWCNT-OH due to the higher content of hydroxyl groups. Despite the glass transition temperatures (Tg) of all the surfactant-treated composites lower compared with Tg for pure polystyrene, they increase for MWCNTs and MWCNT-OH composite without surfactant.

High fluorescence emission of carboxylic acid functionalized polystyrene/BaTiO{sub 3} nanocomposites and rare earth metal complexes: Preparation and characterization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cao, X. T.; Showkat, A. M.; Wang, Z.

2015-03-30

Noble fluorescence nanocomposite compound based on barium titanate nanoparticles (BTO), polystyrene (PSt), and terbium ion (Tb{sup 3+}) was synthesized by a combination of surface-initiated reversible addition-fragmentation chain transfer (RAFT) polymerization, Friedel-Crafts alkylation reaction and coordinate chemistry. Initially, a modification of surface of BTO was conducted by an exchange process with S-benzyl S’-trimethoxysilylpropyltrithiocarbonate to create macro-initiator for polymerization of styrene. Subsequently, aryl carboxylic acid functionalized polystyrene grafted barium titanate (BTO-g-PSt-COOH) was generated by substitution reaction between 4-(Chloromethyl) benzoic acid and PSt chains. The coordination of the nanohybrids with Tb{sup 3+} ions afforded fluorescent Tb{sup 3+} tagged aryl carboxylic acid functionalized polystyrenemore » grafted barium titanate (BTO-g-PSt-Tb{sup 3+}) complexes. Structure, morphology, and fluorescence properties of nanohybrid complexes were investigated by respective physical and spectral studies. FT-IR and SEM analyses confirmed the formation of BTO-g-PSt-Tb{sup 3+}nanohybrids. Furthermore, TGA profiles demonstrated the grafting of aryl carboxylic acid functionalized polystyrene on BTO surface. Optical properties of BTO-g-PSt-Tb{sup 3+} complexes were investigated by fluorescence spectroscopy.« less

Microplasma array patterning of reactive oxygen and nitrogen species onto polystyrene

NASA Astrophysics Data System (ADS)

Szili, Endre J.; Dedrick, James; Oh, Jun-Seok; Bradley, James W.; Boswell, Roderick W.; Charles, Christine; Short, Robert D.; Al-Bataineh, Sameer A.

2017-02-01

We investigate an approach for the patterning of reactive oxygen and nitrogen species (RONS) onto polystyrene using atmospheric-pressure microplasma arrays. The spectrally integrated and time-resolved optical emission from the array is characterised with respect to the applied voltage, applied-voltage frequency and pressure; and the array is used to achieve spatially resolved modification of polystyrene at three pressures: 500 Torr, 760 Torr and 1000 Torr. As determined by time-of-flight secondary ion mass spectrometry (ToF-SIMS), regions over which surface modification occurs are clearly restricted to areas that are exposed to individual microplasma cavities. Analysis of the negative-ion ToF-SIMS mass spectra from the centre of the modified microspots shows that the level of oxidation is dependent on the operating pressure, and closely correlated with the spatial distribution of the optical emission. The functional groups that are generated by the microplasma array on the polystyrene surface are shown to readily participate in an oxidative reaction in phosphate buffered saline solution (pH 7.4). Patterns of oxidised and chemically reactive functionalities could potentially be applied to the future development of biomaterial surfaces, where spatial control over biomolecule or cell function is needed.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guan, Jiwen; Song, Yang, E-mail: yang.song@uwo.ca; Department of Chemistry, University of Western Ontario, London, Ontario N6A 5B7

The polymerization process of condensed styrene to produce polystyrene as an industrially important polymeric material was investigated using a novel approach by combining external compression with ultraviolet radiation. The reaction evolution was monitored as a function of time and the reaction products were characterized by in situ Fourier transform infrared spectroscopy. By optimizing the loading pressures, we observed highly efficient and selective production of polystyrene of different tacticities. Specifically, at relatively low loading pressures, infrared spectra suggest that styrene monomers transform to amorphous atactic polystyrene (APS) with minor crystalline isotactic polystyrene. In contrast, APS was found to be the solemore » product when polymerization occurs at relatively higher loading pressures. The time-dependent reaction profiles allow the examination of the polymerization kinetics by analyzing the rate constant and activation volume as a function of pressure. As a result, an optimized pressure condition, which allows a barrierless reaction to proceed, was identified and attributed to the very desirable reaction yield and kinetics. Finally, the photoinitiated reaction mechanism and the growth geometry of the polymer chains were investigated from the energy diagram of styrene and by the topology analysis of the crystal styrene. This study shows strong promise to produce functional polymeric materials in a highly efficient and controlled manner.« less

Direct covalent attachment of small peptide antigens to enzyme-linked immunosorbent assay plates using radiation and carbodiimide activation.

PubMed

Dagenais, P; Desprez, B; Albert, J; Escher, E

1994-10-01

Direct adsorption of small peptide antigens to unaltered, commercially available polystyrene surfaces may be too weak to permit suitable assay by ELISA. We therefore developed a simple method for the covalent attachment of small, potentially single epitope antigens to polystyrene surfaces. Chemical activation of polystyrene plates with carbodiimide considerably improves the total and covalent attachment of radioactive octapeptides. The covalent attachment was demonstrated by washing with hot detergent. A 3.5 Mrad gamma-irradiation of plates also increases total binding, particularly in combination with chemical activation. The covalent attachment presumably occurs through formation and chemical activation of carboxylate functions on the polystyrene surface which form amide bonds with peptides. ELISA test was performed with CGRP and successive smaller CGRP fragments. Covalent attachment of C-terminal peptide fragments as detection antigens allows optimal recognition and sensitivity even for hexapeptides, while decapeptide antigens were already poorly recognized using a conventional antigen plating technique. Repetitive detergent washes and/or prolonged storage of plates with covalently bound antigens did not reduce their ELISA sensitivity. The method with storage and reutilization capacities that we present here will be useful for the development of preplated antibody screening test.

Fine-tuning of process conditions to improve product uniformity of polystyrene particles used for wind tunnel velocimetry

NASA Technical Reports Server (NTRS)

Ray, Asit K.

1990-01-01

Monodisperse polymer particles (having uniform diameter) were used for the last two decades in physical, biological, and chemical sciences. In NASA Langley Research Center monodisperse polystyrene particles are used in wind tunnel laser velocimeters. These polystyrene (PS) particles in latex form were formulated at the Engineering Laboratory of FENGD using emulsion-free emulsion polymerization. Monodisperse PS latices particles having different particle diameters were formulated and useful experimental data involving effects of process conditions on particle size were accumulated. However, similar process conditions and chemical recipes for polymerization of styrene monomer have often yielded monodisperse particles having varying diameters. The purpose was to improve the PS latex product uniformity by fine-tuning the process parameters based on the knowledge of suspension and emulsion polymerization.

Elastic properties of protein functionalized nanoporous polymer films

DOE PAGES

Charles T. Black; Wang, Haoyu; Akcora, Pinar

2015-12-16

Retaining the conformational structure and bioactivity of immobilized proteins is important for biosensor designs and drug delivery systems. Confined environments often lead to changes in conformation and functions of proteins. In this study, lysozyme is chemically tethered into nanopores of polystyrene thin films, and submicron pores in poly(methyl methacrylate) films are functionalized with streptavidin. Nanoindentation experiments show that stiffness of streptavidin increases with decreasing submicron pore sizes. Lysozymes in polystyrene nanopores are found to behave stiffer than the submicron pore sizes and still retain their specific bioactivity relative to the proteins on flat surfaces. Lastly, our results show that proteinmore » functionalized ordered nanoporous polystyrene/poly(methyl methacrylate) films present heterogeneous elasticity and can be used to study interactions between free proteins and designed surfaces.« less

Monolayer Colloidal Crystals by Modified Air-Water Interface Self-Assembly Approach

PubMed Central

Ye, Xin; Huang, Jin; Zeng, Yong; Sun, Lai-Xi; Geng, Feng; Liu, Hong-Jie; Wang, Feng-Rui; Jiang, Xiao-Dong; Wu, Wei-Dong; Zheng, Wan-Guo

2017-01-01

Hexagonally ordered arrays of polystyrene (PS) microspheres were prepared by a modified air-water self-assembly method. A detailed analysis of the air-water interface self-assembly process was conducted. Several parameters affect the quality of the monolayer colloidal crystals, i.e., the colloidal microsphere concentration on the latex, the surfactant concentration, the polystyrene microsphere diameter, the microsphere polydispersity, and the degree of sphericity of polystyrene microspheres. An abrupt change in surface tension was used to improve the quality of the monolayer colloidal crystal. Three typical microstructures, i.e., a cone, a pillar, and a binary structure were prepared by reactive-ion etching using a high-quality colloidal crystal mask. This study provides insight into the production of microsphere templates with flexible structures for large-area patterned materials. PMID:28946664

Study of the solubility and stability of polystyrene wastes in a dissolution recycling process

DOE Office of Scientific and Technical Information (OSTI.GOV)

Garcia, Maria Teresa; Gracia, Ignacio; Duque, Gema

2009-06-15

Dissolution with suitable solvents is one of the cheapest and more efficient processes for polystyrene waste management. In this work the solubility of polystyrene foams in several solvents benzene, toluene, xylene, tetrahydrofuran, chloroform, 1,3-butanediol, 2-butanol, linalool, geraniol, d-limonene, p-cymene, terpinene, phellandrene, terpineol, menthol, eucalyptol, cinnamaldheyde, nitrobenzene, N,N-dimethylformamide and water has been determined. Experimental results have shown that to develop a 'green process' the constituents of essential oils, d-limonene, p-cymene, terpinene, phellandrene, are the most appropriate solvents. The action of these solvent does not produce any degradation of polymer chains. The solubility of the polymer in the mentioned solvents at differentmore » temperatures has been investigated. The solvent can be easily recycled by distillation.« less

Symmetric and asymmetric instability of buried polymer interfaces

NASA Astrophysics Data System (ADS)

de Silva, J. P.; Cousin, F.; Wildes, A. R.; Geoghegan, M.; Sferrazza, M.

2012-09-01

We demonstrate using neutron reflectometry that the internal interfaces in a trilayer system of two identical thick polystyrene layers sandwiching a much thinner (deuterated) poly(methyl methacrylate) layer 15 nm thick (viscosity matched with the polystyrene layers) increase in roughness at the same rate. When the lower polystyrene layer is replaced with a layer of the same polymer of much greater molecular mass, two different growths of the interfaces are observed. From the growth of the interface for this asymmetric case in the solid regime using the theoretical prediction of the spinodal instability including slippage at the interface, a value of the Hamaker constant of the system has been extracted in agreement with the calculated value. For the symmetric case the rise time of the instability is much faster.

Signal enhancement using a switchable magnetic trap

DOEpatents

Beer, Neil Reginald [Pleasanton, CA

2012-05-29

A system for analyzing a sample including providing a microchannel flow channel; associating the sample with magnetic nanoparticles or magnetic polystyrene-coated beads; moving the sample with said magnetic nanoparticles or magnetic polystyrene-coated beads in the microchannel flow channel; holding the sample with the magnetic nanoparticles or magnetic polystyrene-coated beads in a magnetic trap in the microchannel flow channel; and analyzing the sample obtaining an enhanced analysis signal. An apparatus for analysis of a sample includes magnetic particles connected to the sample, a microchip, a flow channel in the microchip, a source of carrier fluid connected to the flow channel for moving the sample in the flow channel, an electromagnet trap connected to the flow line for selectively magnetically trapping the sample and the magnetic particles, and an analyzer for analyzing the sample.

21 CFR 178.3010 - Adjuvant substances used in the manufacture of foamed plastics.

Code of Federal Regulations, 2014 CFR

2014-04-01

... Limitations Azodicarbonamide For use as a blowing agent in pol-yethylene complying with item 2.1 in § 177.1520...-Difluoroethane (CAS Reg. No. 75-37-6) For use as a blowing agent in polystyrene. Isopentane For use as a blowing agent in polystyrene. n-Pentane Do. 1,1,2,2-Tetra-chloroethylene For use only as a blowing agent...

PREPARATION OF BLOCK COPOLYMERS OF POLY(STYRENE) AND POLY(T-BUTYL ACRYLATE) OF VARIOUS MOLECULAR WEIGHTS AND ARCHITECTURES BY ATOM TRANSFER RADICAL POLYMERIZATION. (R826735)

EPA Science Inventory

Block copolymers of polystyrene and poly(t-butyl acrylate) were prepared using atom transfer radical polymerization techniques. These polymers were synthesized with a CuBr/N,N,N,NRational design of Raman-labeled nanoparticles for a dual-modality, light scattering immunoassay on a polystyrene substrate.

PubMed

Israelsen, Nathan D; Wooley, Donald; Hanson, Cynthia; Vargis, Elizabeth

2016-01-01

Surface-enhanced Raman scattering (SERS) is a powerful light scattering technique that can be used for sensitive immunoassay development and cell labeling. A major obstacle to using SERS is the complexity of fabricating SERS probes since they require nanoscale characterization and optical uniformity. The light scattering response of SERS probes may also be modulated by the substrate used for SERS analysis. A typical SERS substrate such as quartz can be expensive. Polystyrene is a cheaper substrate option but can decrease the SERS response due to interfering Raman emission peaks and high background fluorescence. The goal of this research is to develop an optimized process for fabricating Raman-labeled nanoparticles for a SERS-based immunoassay on a polystyrene substrate. We have developed a method for fabricating SERS nanoparticle probes for use in a light scattering immunoassay on a polystyrene substrate. The light scattering profile of both spherical gold nanoparticle and gold nanorod SERS probes were characterized using Raman spectroscopy and optical absorbance spectroscopy. The effects of substrate interference and autofluorescence were reduced by selecting a Raman reporter with a strong light scattering response in a spectral region where interfering substrate emission peaks are minimized. Both spherical gold nanoparticles and gold nanorods SERS probes used in the immunoassay were detected at labeling concentrations in the low pM range. This analytical sensitivity falls within the typical dynamic range for direct labeling of cell-surface biomarkers using SERS probes. SERS nanoparticle probes were fabricated to produce a strong light scattering signal despite substrate interference. The optical extinction and inelastic light scattering of these probes was detected by optical absorbance spectroscopy and Raman spectroscopy, respectively. This immunoassay demonstrates the feasibility of analyzing strongly enhanced Raman signals on polystyrene, which is an inexpensive yet non-ideal Raman substrate. The assay sensitivity, which is in the low pM range, suggests that these SERS probe particles could be used for Raman labeling of cell or tissue samples in a polystyrene tissue culture plate. With continued development, this approach could be used for direct labeling of multiple cell surface biomarkers on strongly interfering substrate platforms.

Biocompatibility, endocytosis, and intracellular trafficking of mesoporous silica and polystyrene nanoparticles in ovarian cancer cells: effects of size and surface charge groups

PubMed Central

Ekkapongpisit, Maneerat; Giovia, Antonino; Follo, Carlo; Caputo, Giuseppe; Isidoro, Ciro

2012-01-01

Background and methods Nanoparticles engineered to carry both a chemotherapeutic drug and a sensitive imaging probe are valid tools for early detection of cancer cells and to monitor the cytotoxic effects of anticancer treatment simultaneously. Here we report on the effect of size (10–30 nm versus 50 nm), type of material (mesoporous silica versus polystyrene), and surface charge functionalization (none, amine groups, or carboxyl groups) on biocompatibility, uptake, compartmentalization, and intracellular retention of fluorescently labeled nanoparticles in cultured human ovarian cancer cells. We also investigated the involvement of caveolae in the mechanism of uptake of nanoparticles. Results We found that mesoporous silica nanoparticles entered via caveolae-mediated endocytosis and reached the lysosomes; however, while the 50 nm nanoparticles permanently resided within these organelles, the 10 nm nanoparticles soon relocated in the cytoplasm. Naked 10 nm mesoporous silica nanoparticles showed the highest and 50 nm carboxyl-modified mesoporous silica nanoparticles the lowest uptake rates, respectively. Polystyrene nanoparticle uptake also occurred via a caveolae-independent pathway, and was negatively affected by serum. The 30 nm carboxyl-modified polystyrene nanoparticles did not localize in lysosomes and were not toxic, while the 50 nm amine-modified polystyrene nanoparticles accumulated within lysosomes and eventually caused cell death. Ovarian cancer cells expressing caveolin-1 were more likely to endocytose these nanoparticles. Conclusion These data highlight the importance of considering both the physicochemical characteristics (ie, material, size and surface charge on chemical groups) of nanoparticles and the biochemical composition of the cell membrane when choosing the most suitable nanotheranostics for targeting cancer cells. PMID:22904626

Accurate control of oxygen level in cells during culture on silicone rubber membranes with application to stem cell differentiation.

PubMed

Powers, Daryl E; Millman, Jeffrey R; Bonner-Weir, Susan; Rappel, Michael J; Colton, Clark K

2010-01-01

Oxygen level in mammalian cell culture is often controlled by placing culture vessels in humidified incubators with a defined gas phase partial pressure of oxygen (pO(2gas)). Because the cells are consuming oxygen supplied by diffusion, a difference between pO(2gas) and that experienced by the cells (pO(2cell)) arises, which is maximal when cells are cultured in vessels with little or no oxygen permeability. Here, we demonstrate theoretically that highly oxygen-permeable silicone rubber membranes can be used to control pO(2cell) during culture of cells in monolayers and aggregates much more accurately and can achieve more rapid transient response following a disturbance than on polystyrene and fluorinated ethylene-propylene copolymer membranes. Cell attachment on silicone rubber was achieved by physical adsorption of fibronectin or Matrigel. We use these membranes for the differentiation of mouse embryonic stem cells to cardiomyocytes and compare the results with culture on polystyrene or on silicone rubber on top of polystyrene. The fraction of cells that are cardiomyocyte-like increases with decreasing pO(2) only when using oxygen-permeable silicone membrane-based dishs, which contract on silicone rubber but not polystyrene. The high permeability of silicone rubber results in pO(2cell) being equal to pO(2gas) at the tissue-membrane interface. This, together with geometric information from histological sections, facilitates development of a model from which the pO(2) distribution within the resulting aggregates is computed. Silicone rubber membranes have significant advantages over polystyrene in controlling pO(2cell), and these results suggest they are a valuable tool for investigating pO(2) effects in many applications, such as stem cell differentiation. Copyright 2009 American Institute of Chemical Engineers

Chitosan-coated polystyrene microplate for covalent immobilization of enzyme.

PubMed

Zhang, Yaodong; Li, Li; Yu, Caihong; Hei, Tingting

2011-10-01

Microplates made of polystyrene have been widely used for immunoassays. Protein molecules that have been immobilized on a hydrophobic polystyrene microplate by passive adsorption lose their activity and suffer considerable denaturation. A new chitosan-coated microplate suitable for the covalent immobilization of enzymes has been developed. The primary amino groups of chitosan were exploited for this covalent coupling of proteins. The optical transmittance of the chitosan-coated microplate, at wavelengths of 400-800 nm, was estimated to be suitable for its application in chromogenic reaction-based bioassays. The immobilization efficiency of the chitosan-coated microplate was demonstrated to be far superior to that of a conventional microplate when tested using acetylcholinesterase (AChE) and β-glucosidase as model biomolecules, and the chitosan-coated microplate may thus have potential applications in biosensing and bioreactor systems. © Springer-Verlag 2011

A system for electron therapy dosimetry surveys with thermoluminescence dosimeters.

PubMed

Soares, C G; Ehrlich, M; Padikal, T N; Gromadzki, Z C

1982-11-01

Radiation-therapy dosimetry surveys employing thermoluminescence dosimeters (TLDs) are now being considered for high-energy electron beams. Using a system of individually calibrated pressed LiF TLDs in a water and a polystyrene phantom, we established that the distortions of depth-dose distributions in non-conducting materials previously observed at high absorbed doses and high dose rates were not detectable in the present geometry at doses and dose rates as much as 40 times higher than those employed in radiation therapy. The system was then used to measure TLD response in water and in polystyrene in the nominal electron-energy range from 7 to 18 MeV. In the water phantom, the well-known trend for TLD response to decrease with increasing electron energy was observed. In the polystyrene phantom, TLD response was found to be independent of electron energy.

Bending and Force Recovery in Polymer Films and Microgel Formation

NASA Astrophysics Data System (ADS)

Elder, Theresa Marie

To determine correlation between geometry and material three different model films: polymethylsiloxane (PDMS), polystyrene (PS), and polycarbonate (PC), were singly bent and doubly bent (forming D-cones). Bends were chosen as they are fundamental in larger complex geometries such as origami and crumples. Bending was carried out between two plates taking force and displacement measurements. Processing of data using moment equations yielded values for bending moduli for studied films that were close to accepted values. Force recovery showed logarithmic trends for PDMS and stretched exponential trends for PS and PC. In a separate experiment a triblock copolymer of polystyrene-polyacrylic acid-polystyrene was subjected to different good and bad solvent mixing with any resulting particle morphology examined. Particles formed more uniformly with high water concentration, particles formed with high toluene concentration and agitation yielded three separate morphologies.

Polystyrene negative resist for high-resolution electron beam lithography

PubMed Central

2011-01-01

We studied the exposure behavior of low molecular weight polystyrene as a negative tone electron beam lithography (EBL) resist, with the goal of finding the ultimate achievable resolution. It demonstrated fairly well-defined patterning of a 20-nm period line array and a 15-nm period dot array, which are the densest patterns ever achieved using organic EBL resists. Such dense patterns can be achieved both at 20 and 5 keV beam energies using different developers. In addition to its ultra-high resolution capability, polystyrene is a simple and low-cost resist with easy process control and practically unlimited shelf life. It is also considerably more resistant to dry etching than PMMA. With a low sensitivity, it would find applications where negative resist is desired and throughput is not a major concern. PMID:21749679

Assessment of phototoxicity, skin irritation, and sensitization potential of polystyrene and TiO2 nanoparticles

NASA Astrophysics Data System (ADS)

Park, Yoon-Hee; Jeong, Sang Hoon; Yi, Sang Min; Hyeok Choi, Byeong; Kim, Yu-Ri; Kim, In-Kyoung; Kim, Meyoung-Kon; Son, Sang Wook

2011-07-01

The human skin equivalent model (HSEM) is well known as an attractive alternative model for evaluation of dermal toxicity. However, only limited data are available on the usefulness of an HSEM for nanotoxicity testing. This study was designed to investigate cutaneous toxicity of polystyrene and TiO2 nanoparticles using cultured keratinocytes, an HSEM, and an animal model. In addition, we also evaluated the skin sensitization potential of nanoparticles using a local lymph node assay with incorporation of BrdU. Findings from the present study indicate that polystyrene and TiO2 nanoparticles do not induce phototoxicity, acute cutaneous irritation, or skin sensitization. Results from evaluation of the HSEMs correspond well with those from animal models. Our findings suggest that the HSEM might be a useful alternative model for evaluation of dermal nanotoxicity.

Third-order nonlinear optical properties of phthalocyanines in solution and in polystyrene films

NASA Astrophysics Data System (ADS)

Reeves, Roger J.; Powell, Richard C.; Chang, Young H.; Ford, Warren T.; Zhu, Weiming

1996-01-01

Degenerate four-wave mixing (DFWM) measurements of third-order nonlinear optical (NLO) coefficients of metal-free, Cu, Pt, Pb and Bi octa(2-ethylhexyloxy) phthalocyanines (MPc's) were done with 20 ps duration laser pulses under resonant conditions at 532 nm in polystyrene films and under nonresonant conditions at 1064 nm in chloroform solutions. The NLO coefficients ξxxxx(3) show saturation with increasing incident intensity and no strong dependence on the central metal atom of the MPc below the saturation intensity. Optical delays of the probe-pulse up to 3 ns show an acoustic phonon response in both the polystyrene films and the chloroform solutions. An intensity-dependent absorption coefficient was measured by a pump/probe experiment and used in a simple model to qualitatively account for the saturation of ξ(3) measured by DFWM.

Effects of the alkylamine functionalization of graphene oxide on the properties of polystyrene nanocomposites

NASA Astrophysics Data System (ADS)

Jang, Jinhee; Pham, Viet Hung; Rajagopalan, Balasubramaniyan; Hur, Seung Hyun; Chung, Jin Suk

2014-05-01

Alkylamine-functionalized graphene oxides (FGOs) have superior dispersibility in low-polar solvents and, as a result, they interact with low-polar polymers such as polystyrene. In this work, the functionalization of graphene oxide using three types of alkylamines, octylamine (OA), dodecylamine (DDA), and hexadecylamine (HDA), was performed, and nanocomposites of polystyrene (PS) and FGOs were prepared via solution blending. Different dispersions of FGOs over PS were obtained for the three alkylamines, and the properties of the PS composites were influenced by the length of the alkylamine. A better thermal stability was observed with a longer chain length of the alkylamine. On the other hand, functionalization with the shortest chain length alkylamine resulted in the highest increase in the storage modulus (3,640 MPa, 140%) at a 10 wt.% loading of FGO.

From the 2-dimensional unstable polyelectrolyte multilayer to the 3-dimensional stable dry polyelectrolyte capsules.

PubMed

Li, Xiaodong; Zhang, Jianxiang; Hu, Qiaoling; Li, Xiaohui

2011-11-01

Polystyrene-poly(acrylic acid)/poly(allylamine hydrochloride) polyelectrolyte multilayer was found to be instable and apt to reconstruct in the pure water. By depositing polystyrene-poly(acrylic acid)/poly(allylamine hydrochloride) multilayer on the polystyrene-poly(acrylic acid) hybrid CaCO(3) templates, novel polyelectrolyte capsules could be prepared after the removal of the templates. The resultant capsules could keep their three-dimensional (3D) spherical shape after being dried at room temperature, dramatically different from the conventional polyelectrolyte capsules based on nonhybrid templates by layer-by-layer procedure. The instable polyelectrolyte multilayer, hybrid templates, and assembly cycles were demonstrated to be three indispensable factors responsible for the formation of this type of 3D stable capsules. The formation mechanism was also discussed in this study. Copyright © 2011 Elsevier Inc. All rights reserved.

Design of polystyrene latex particles covered with polyoxometalate clusters via multiple covalent bonding

DOE PAGES

Chen, Xinyue; Li, Hui; Yin, Panchao; ...

2015-02-27

In this study, polyoxometalates (POMs) covalently functionalized with methyl methacrylate groups were applied as surfactants in the emulsion polymerization reaction of styrene. Due to the copolymerization of the methyl methacrylate groups and the styrene monomers, the polyoxometalate clusters are covalently grafted onto the surface of polystyrene latex nanoparticles. Finally, such latex particles are fully covered with catalytic POM clusters and might serve as quasi-homogeneous catalysts.

PMMA and polystyrene films modification under ion implantation studied by spectroscopic ellipsometry

NASA Astrophysics Data System (ADS)

Leontyev, A. V.; Kovalev, V. I.; Khomich, A. V.; Komarov, Fadei F.; Grigoryev, V. V.; Kamishan, A. S.

2004-05-01

We have applied spectroscopic ellipsometry with binary polarization modulation to study the refractive index n(λ) and extinction coefficient k(λ) spectra of as-deposited and irradiated with nitrogen ions polymethylmethacrylate (PMMA) and polystyrene (PS) films in 300-1030 nm range. The results of performed investigation confirmed the possibility and estimate restrictions of the ion implantation for local change the refractive index of polymeric materials.

Ballistic Imaging and Scattering Measurements for Diesel Spray Combustion: Optical Development and Phenomenological Studies

DTIC Science & Technology

2016-04-01

polystyrene spheres in a water suspension. The impact of spatial filtering , temporal filtering , and scattering path length on image resolution are...The impact of spatial filtering , temporal filtering , and scattering path length on image resolution are reported. The technique is demonstrated...cell filled with polystyrene spheres in a water suspension. The impact of spatial filtering , temporal filtering , and scattering path length on image

Oriented antibody immobilization to polystyrene macrocarriers for immunoassay modified with hydrazide derivatives of poly(meth)acrylic acid

PubMed Central

Shmanai, Vadim V; Nikolayeva, Tamara A; Vinokurova, Ludmila G; Litoshka, Anatoli A

2001-01-01

Background Hydrophobic polystyrene is the most common material for solid phase immunoassay. Proteins are immobilized on polystyrene by passive adsorption, which often causes considerable denaturation. Biological macromolecules were found to better retain their functional activity when immobilized on hydrophilic materials. Polyacrylamide is a common material for solid-phase carriers of biological macromolecules, including immunoreagents used in affinity chromatography. New macroformats for immunoassay modified with activated polyacrylamide derivatives seem to be promising. Results New polymeric matrices for immunoassay in the form of 0.63-cm balls which contain hydrazide functional groups on hydrophilic polymer spacer arms at their surface shell are synthesized by modification of aldehyde-containing polystyrene balls with hydrazide derivatives of poly(meth)acrylic acid. The beads contain up to 0.31 μmol/cm2 active hydrazide groups accessible for covalent reaction with periodate-oxidized antibodies. The matrices obtained allow carrying out the oriented antibody immobilization, which increases the functional activity of immunosorbents. Conclusions An efficient site-directed antibody immobilization on a macrosupport is realized. The polymer hydrophilic spacer arms are the most convenient and effective tools for oriented antibody coupling with molded materials. The suggested scheme can be used for the modification of any other solid supports containing electrophilic groups reacting with hydrazides. PMID:11545680

Polystyrene-Divinylbenzene-Based Adsorbents Reduce Endothelial Activation and Monocyte Adhesion Under Septic Conditions in a Pore Size-Dependent Manner.

PubMed

Eichhorn, Tanja; Rauscher, Sabine; Hammer, Caroline; Gröger, Marion; Fischer, Michael B; Weber, Viktoria

2016-10-01

Endothelial activation with excessive recruitment and adhesion of immune cells plays a central role in the progression of sepsis. We established a microfluidic system to study the activation of human umbilical vein endothelial cells by conditioned medium containing plasma from lipopolysaccharide-stimulated whole blood or from septic blood and to investigate the effect of adsorption of inflammatory mediators on endothelial activation. Treatment of stimulated whole blood with polystyrene-divinylbenzene-based cytokine adsorbents (average pore sizes 15 or 30 nm) prior to passage over the endothelial layer resulted in significantly reduced endothelial cytokine and chemokine release, plasminogen activator inhibitor-1 secretion, adhesion molecule expression, and in diminished monocyte adhesion. Plasma samples from sepsis patients differed substantially in their potential to induce endothelial activation and monocyte adhesion despite their almost identical interleukin-6 and tumor necrosis factor-alpha levels. Pre-incubation of the plasma samples with a polystyrene-divinylbenzene-based adsorbent (30 nm average pore size) reduced endothelial intercellular adhesion molecule-1 expression to baseline levels, resulting in significantly diminished monocyte adhesion. Our data support the potential of porous polystyrene-divinylbenzene-based adsorbents to reduce endothelial activation under septic conditions by depletion of a broad range of inflammatory mediators.

Highly efficient and selective pressure-assisted photon-induced polymerization of styrene

NASA Astrophysics Data System (ADS)

Guan, Jiwen; Song, Yang

2016-06-01

The polymerization process of condensed styrene to produce polystyrene as an industrially important polymeric material was investigated using a novel approach by combining external compression with ultraviolet radiation. The reaction evolution was monitored as a function of time and the reaction products were characterized by in situ Fourier transform infrared spectroscopy. By optimizing the loading pressures, we observed highly efficient and selective production of polystyrene of different tacticities. Specifically, at relatively low loading pressures, infrared spectra suggest that styrene monomers transform to amorphous atactic polystyrene (APS) with minor crystalline isotactic polystyrene. In contrast, APS was found to be the sole product when polymerization occurs at relatively higher loading pressures. The time-dependent reaction profiles allow the examination of the polymerization kinetics by analyzing the rate constant and activation volume as a function of pressure. As a result, an optimized pressure condition, which allows a barrierless reaction to proceed, was identified and attributed to the very desirable reaction yield and kinetics. Finally, the photoinitiated reaction mechanism and the growth geometry of the polymer chains were investigated from the energy diagram of styrene and by the topology analysis of the crystal styrene. This study shows strong promise to produce functional polymeric materials in a highly efficient and controlled manner.

Block Copolymer-Based Supramolecular Elastomers with High Extensibility and Large Stress Generation Capability

NASA Astrophysics Data System (ADS)

Noro, Atsushi; Hayashi, Mikihiro

We prepared block copolymer-based supramolecular elastomers with high extensibility and large stress generation capability. Reversible addition fragmentation chain transfer polymerizations were conducted under normal pressure and high pressure to synthesize several large molecular weight polystyrene-b-[poly(butyl acrylate)-co-polyacrylamide]-b-polystyrene (S-Ba-S) block copolymers. Tensile tests revealed that the largest S-Ba-S with middle block molecular weight of 3140k achieved a breaking elongation of over 2000% with a maximum tensile stress of 3.6 MPa and a toughness of 28 MJ/m3 while the reference sample without any middle block hydrogen bonds, polystyrene-b-poly(butyl acrylate)-b-polystyrene with almost the same molecular weight, was merely viscous and not self-standing. Hence, incorporation of hydrogen bonds into a long soft middle block was found to be beneficial to attain high extensibility and large stress generation capability probably due to concerted combination of entropic changes and internal potential energy changes originaing from the dissociation of multiple hydrogen bonds by elongation. This work was supported by JSPS KAKENHI Grant Numbers 13J02357, 24685035, 15K13785, and 23655213 for M.H. and A.N. A.N. also expresses his gratitude for Tanaka Rubber Science & Technology Award by Enokagaku-Shinko Foundation, Japan.

Co-release of hexabromocyclododecane (HBCD) and Nano- and microparticles from thermal cutting of polystyrene foams.

PubMed

Zhang, Haijun; Kuo, Yu-Ying; Gerecke, Andreas C; Wang, Jing

2012-10-16

Polystyrene foam is a very important insulation material, and hexabromocyclododecane (HBCD) is frequently used as its flame retardant. HBCD is persistent, bioaccumulative, and toxic, and therefore workplace exposure and environmental emission should be avoided. In this study, we investigated the co-release of HBCD and aerosol particles during the thermal cutting of expanded polystyrene foam (EPS) and extruded polystyrene foam (XPS). The generated particles were simultaneously measured by a fast mobility particle sizer (FMPS) and collected by a cascade impactor (NanoMoudi). In the breathing zone of a cutting worker, the number concentration of aerosol particles was above 1 × 10(12) particles m(-3), and the air concentration of HBCD was more than 50 μg m(-3). Most of the released HBCD was partitioned into particles with an aerodynamic diameter at the nanometer scale. The average concentrations of HBCD in these submicrometer particles generated from the thermal cutting of EPS and XPS were 13 times and 15 times higher than the concentrations in raw foams, respectively. An occupational exposure assessment indicated that more than 60% of HBCD and 70% of particles deposited in the lung of cutting worker would be allocated to the alveolar region. The potential subchronic (or chronic) toxicity jointly caused by the particles and HBCD calls for future studies.

Sorption of organic compounds by aged polystyrene microplastic particles.

PubMed

Hüffer, Thorsten; Weniger, Anne-Katrin; Hofmann, Thilo

2018-05-01

Microplastics that are released into the environment undergo aging and interact with other substances such as organic contaminants. Understanding the sorption interactions between aged microplastics and organic contaminants is therefore essential for evaluating the impact of microplastics on the environment. There is little information available on how the aging of microplastics affects their sorption behavior and other properties. We have therefore investigated the effects of an accelerated UV-aging procedure on polystyrene microplastics, which are used in products such as skin cleaners and foams. Physical and chemical particle characterizations showed that aging led to significant surface oxidation and minor localized microcrack formation. Sorption coefficients of organic compounds by polystyrene microplastics following aging were up to one order of magnitude lower than for pristine particles. Sorption isotherms were experimentally determined using a diverse set of probe sorbates covering a variety of substance classes allowing an in-depth evaluation of the poly-parameter linear free-energy relationship (ppLFER) modelling used to investigate the contribution of individual molecular interactions to overall sorption. The ppLFER modelling was validated using internal cross-validation, which confirmed its robustness. This approach therefore yields improved estimates of the interactions between aged polystyrene microplastics and organic contaminants. Copyright © 2018 Elsevier Ltd. All rights reserved.

Chemical vapor deposition of mesoporous graphene nanoballs for supercapacitor.

PubMed

Lee, Jung-Soo; Kim, Sun-I; Yoon, Jong-Chul; Jang, Ji-Hyun

2013-07-23

A mass-producible mesoporous graphene nanoball (MGB) was fabricated via a precursor-assisted chemical vapor deposition (CVD) technique for supercapacitor application. Polystyrene balls and reduced iron created under high temperature and a hydrogen gas environment provide a solid carbon source and a catalyst for graphene growth during the precursor-assisted CVD process, respectively. Carboxylic acid and sulfonic acid functionalization of the polystyrene ball facilitates homogeneous dispersion of the hydrophobic polymer template in the metal precursor solution, thus, resulting in a MGB with a uniform number of graphene layers. The MGB is shown to have a specific surface area of 508 m(2)/g and is mesoporous with a mean mesopore diameter of 4.27 nm. Mesopores are generated by the removal of agglomerated iron domains, permeating down through the soft polystyrene spheres and providing the surface for subsequent graphene growth during the heating process in a hydrogen environment. This technique requires only drop-casting of the precursor/polystyrene solution, allowing for mass-production of multilayer MGBs. The supercapacitor fabricated by the use of the MGB as an electrode demonstrates a specific capacitance of 206 F/g and more than 96% retention of capacitance after 10,000 cycles. The outstanding characteristics of the MGB as an electrode for supercapacitors verify the strong potential for use in energy-related areas.

Electron beam transport in heterogeneous slab media from MeV down to eV.

PubMed

Yousfi, M; Leger, J; Loiseau, J F; Held, B; Eichwald, O; Defoort, B; Dupillier, J M

2006-01-01

An optimized Monte Carlo method based on the null collision technique and on the treatment of individual interactions is used for the simulation of the electron transport in multilayer materials from high energies (MeV or several hundred of keV) down to low cutoff energies (between 1 and 10 eV). In order to better understand the electron transport and the energy deposition at the interface in the composite application framework, two layer materials are considered (carbon and polystyrene with densities of 1.7 g cm(-3) and 1.06 g cm(-3), respectively) under two slab or three slab configurations as, e.g. a thin layer of carbon sandwiched between two polystyrene layers. The electron-matter cross-sections (electron-carbon and electron-polystyrene) used in the case of pure material (carbon and polystyrene) as well as our Monte-Carlo code have been first validated. The boundary interface layer is considered without any mean free path truncation and with a rigorous treatment of the backscattered and also the forward scattered electrons from one layer to another. The large effect of the choice of a low cutoff energy and the dissociation process consideration are also clearly shown in the heterogeneous multi-layer media more particularly on the secondary electron emission, inelastic collision number and energy spectra.

The Incredible Shrinking Cup Lab: Connecting with Ocean and Great Lakes Scientists to Investigate the Effect of Depth and Water Pressure on Polystyrene

ERIC Educational Resources Information Center

Rose, Chantelle M.; Adams, Jacqueline M.; Hinchey, Elizabeth K.; Nestlerode, Janet A.; Patterson, Mark R.

2013-01-01

Pressure increases rapidly with depth in a water body. Ocean and Great Lakes scientists often use this physical feature of water as the basis of a fun pastime performed aboard research vessels around the world: the shrinking of polystyrene cups. Depending on the depth to which the cups are deployed, the results can be quite striking! Capitalizing…

A Facile Synthesis of Dynamic, Shape-Changing Polymer Particles

DTIC Science & Technology

2014-04-02

utilizing functional surfactants to control the phase separation of symmetric polystyrene- b -poly(2-vinylpyr- idine) ( PS - b - P2VP ) in dispersed droplets...Figure 1. Schematic representation of a mixed surfactant strategy for controlling the self-assembly of PS - b - P2VP and the generation of particles with...surfactant mixtures to control the phase separation of the symmetric polystyrene- b -poly(2-vinylpyridine) ( PS - b - P2VP ) block copolymers (BCPs) within

Ultra High Quality Factor Microtoroid for Chemical and Biomedical Sensing Applications

DTIC Science & Technology

2013-08-01

PERFORMING ORGANIZATION NAMES AND ADDRESSES U.S. Army Research Office P.O. Box 12211 Research Triangle Park, NC 27709-2211 15. SUBJECT TERMS resonator...PERFORMING ORGANIZATION REPORT NUMBER 19a. NAME OF RESPONSIBLE PERSON 19b. TELEPHONE NUMBER Lan Yang 314-935-9543 3. DATES COVERED (From - To...change. By using this ultra high-Q WGM resonator, radius >75nm polystyrene nanoparticle are detected in aquatic environment. In addition to polystyrene

Macroscopic Modeling of A3B15A3 Triblock Copolymers in B Solvent

DTIC Science & Technology

2010-11-01

matrix composed of the midblock (2). Some examples of TPEs are poly[styrene-butadiene-styrene] (SBS), poly[styrene- isoprene -styrene] (SIS), poly[styrene...92. 19. Hadziioannou, G.; Skoulios, A. Molecular Weight Dependence of Lamellar Structure in Styrene Isoprene Two- and Three-block Copolymers...Microphase Seperation in Styrene- Isoprene Block Copolymers. Macromolecules 1994, 27. 42. Mckay, K. W.; Gros, W. A.; Diehl, C. F. The Influence of

A thermally tunable inverse opal photonic crystal for monitoring glass transition.

PubMed

Sun, Liguo; Xie, Zhuoying; Xu, Hua; Xu, Ming; Han, Guozhi; Wang, Cheng; Bai, Xuduo; Gu, ZhongZe

2012-03-01

An optical method was developed to monitor the glass transition of the polymer by taking advantage of reflection spectrum change of the thermally tunable inverse opal photonic crystal. The thermally tunable photonic bands of the polymer inverse opal photonic crystal were traceable to the segmental motion of macromolecules, and the segmental motion was temperature dependent. By observing the reflection spectrum change of the polystyrene inverse opal photonic crystal during thermal treatment, the glass transition temperature of polystyrene was gotten. Both changes of the position and intensity of the reflection peak were observed during the glass transition process of the polystyrene inverse opal photonic crystal. The optical change of inverse opal photonic crystal was so large that the glass transition temperature could even be estimated by naked eyes. The glass transition temperature derived from this method was consistent with the values measured by differential scanning calorimeter.

Study on selective laser sintering of glass fiber reinforced polystyrene

NASA Astrophysics Data System (ADS)

Yang, Laixia; Wang, Bo; Zhou, Wenming

2017-12-01

In order to improve the bending strength of Polystyrene (PS) sintered parts by selective laser sintering, Polystyrene/glass fiber (PS/GF) composite powders were prepared by mechanical mixing method. The size distribution of PS/GF composite powders was characterized by laser particle size analyzer. The optimum ratio of GF was determined by proportioning sintering experiments. The influence of process parameters on the bending strength of PS and PS/GF sintered parts was studied by orthogonal test. The result indicates that the particle size of PS/GF composite powder is mainly distributed in 24.88 μm~139.8 μm. When the content of GF is 10%, it has better strengthen effect. Finally, the article used the optimum parameter of the two materials to sinter prototype, it is found that the PS/GF prototype has the advantages of good accuracy and high strength.

Thin Film Stability of Polystyrene with a Functional End Group

NASA Astrophysics Data System (ADS)

Tanaka, Keiji; Shimomura, Shinichiro; Inutsuka, Manabu; Tajima, Koichiro; Nabika, Masaaki; Moritomi, Satoru; Matsuno, Hisao; Kyushu Univ. Team; Sumitomo Chemical Co., Ltd. Collaboration

The thin film stability of omega- N-(3-(dimethylamino)propyl)propylamide-terminated polystyrene (PS-N) and its mixture with conventional polystyrene (PS-H) spin-coated on silicon wafers with a native oxide layer was studied. While a 20 nm-thick film of PS-H with a number-average molecular weight of approximately 50k was broken at 423 K, a comparable PS-N film and blend films with a PS-N fraction higher than 40 wt% were stable. Although the local conformation of chains at the substrate interface was not the same for PS with/without the functionalized terminal group, the glass transition temperature at the interface was identical for PS-H and PS-N. The residual adsorbed layer on the substrate after washing the films with toluene was thicker for PS-N than for PS-H. This implies that the end functionalization impacts chain movement on a large scale rather than via segmental dynamics.

Distribution of short block copolymer chains in Binary Blends of Block Copolymers Having Hydrogen Bonding

NASA Astrophysics Data System (ADS)

Kwak, Jongheon; Han, Sunghyun; Kim, Jin Kon

2014-03-01

A binary mixture of two block copolymers whose blocks are capable of forming the hydrogen bonding allows one to obtain various microdomains that could not be expected for neat block copolymer. For instance, the binary blend of symmetric polystyrene-block-poly(2-vinylpyridine) copolymer (PS-b-P2VP) and polystyrene-block-polyhydroxystyrene copolymer (PS-b-PHS) blends where the hydrogen bonding occurred between P2VP and PHS showed hexagonally packed (HEX) cylindrical and body centered cubic (BCC) spherical microdomains. To know the exact location of short block copolymer chains at the interface, we synthesized deuterated polystyrene-block-polyhydroxystyrene copolymer (dPS-b-PHS) and prepared a binary mixture with PS-b-P2VP. We investigate, via small angle X-ray scattering (SAXS) and neutron reflectivity (NR), the exact location of shorter dPS block chain near the interface of the microdomains.

Plasmon-Enhanced Photocleaving Dynamics in Colloidal MicroRNA-Functionalized Silver Nanoparticles Monitored with Second Harmonic Generation.

PubMed

Kumal, Raju R; Abu-Laban, Mohammad; Landry, Corey R; Kruger, Blake; Zhang, Zhenyu; Hayes, Daniel J; Haber, Louis H

2016-10-11

The photocleaving dynamics of colloidal microRNA-functionalized nanoparticles are studied using time-dependent second harmonic generation (SHG) measurements. Model drug-delivery systems composed of oligonucleotides attached to either silver nanoparticles or polystyrene nanoparticles using a nitrobenzyl photocleavable linker are prepared and characterized. The photoactivated controlled release is observed to be most efficient on resonance at 365 nm irradiation, with pseudo-first-order rate constants that are linearly proportional to irradiation powers. Additionally, silver nanoparticles show a 6-fold plasmon enhancement in photocleaving efficiency over corresponding polystyrene nanoparticle rates, while our previous measurements on gold nanoparticles show a 2-fold plasmon enhancement compared to polystyrene nanoparticles. Characterizations including extinction spectroscopy, electrophoretic mobility, and fluorimetry measurements confirm the analysis from the SHG results. The real-time SHG measurements are shown to be a highly sensitive method for investigating plasmon-enhanced photocleaving dynamics in model drug delivery systems.

Migration of styrene and ethylbenzene from virgin and recycled expanded polystyrene containers and discrimination of these two kinds of polystyrene by principal component analysis.

PubMed

Lin, Qin-Bao; Song, Xue-Chao; Fang, Hong; Wu, Yu-Mei; Wang, Zhi-Wei

2017-01-01

The migration of styrene and ethylbenzene from virgin and recycled expanded polystyrene (EPS) containers into isooctane was investigated using gas chromatography-mass spectrometry (GC-MS). EPS containers were in two-sided contact with isooctane at temperatures of 25 and 40°C. It was shown that recycled EPS gave greater migration ratios compared with virgin EPS, which indicated that styrene and ethylbenzene migrated more easily from recycled EPS. In addition, an analytical method to distinguish between virgin and recycled EPS containers was established by GC-MS followed by principal component analysis (PCA). The relative peak area of the identified compounds was used as input data for PCA. Distinct separation between virgin and recycled EPS was achieved on a score plot. Extension of this method to other plastics may be of great interest for recycled plastics identification.

Nanoindentation study of interphases in epoxy/amine thermosetting systems modified with thermoplastics.

PubMed

Ramos, Jose Angel; Blanco, Miren; Zalakain, Iñaki; Mondragon, Iñaki

2009-08-15

The characterization of a mixture of epoxy/amine with different stoichiometric ratios was carried out by means of nanoindentation. The epoxy system was composed by diglycidyl ether of bisphenol-A and 4,4'-methylene bis-(3-chloro 2,6-diethylaniline). Diffusion through interface formed by epoxy/amine system in stoichiometric ratio and several thermoplastic polymers was also analyzed by means of stiffness analysis, as studied by atomic force microscopy (AFM) and coupled nanoindentation tests. Used thermoplastics were an amorphous, atactic polystyrene, and two semicrystalline, syndiotactic polystyrene and poly(phenylene sulfide). Larger range diffusion was obtained in epoxy/amine systems modified with atactic polystyrene while the study of the influence of stoichiometric ratio suggests that the excess of epoxy generated stiffer material. In addition, larger indentation loads resulted in higher apparent stiffness because of the more number of polymer chains that had to re-accommodate owing to the increase in contact area.

Conversion of post consumer waste polystyrene into a high value adsorbent and its sorptive properties for Congo Red removal from aqueous solution.

PubMed

Chaukura, Nhamo; Mamba, Bhekie B; Mishra, Shivani B

2017-05-15

Using post-consumer waste polystyrene (WPS), a conjugated microporous polymer (CMP) was synthesised and activated into a sulphonic-group carrying resin (SCMP). The surface chemistry of the materials showed a decline in both the aromatic CH and aliphatic CH 2 stretching vibrations confirming successful crosslinking. The synthesised polymers were thermally stable with decomposition temperatures above 300 °C, had surface heterogeneity, and BET surface areas of 752 and 510 m 2 /g, respectively. A distribution of pores ranging from meso- to micro-pores was comparable to other CMPs. The materials had maximum adsorption capacities of 500 and 357 mg/g for Congo Red (CR) on CMP and SCMP, respectively. Converting waste polystyrene to an adsorbent is a cost effective way of handling waste and simultaneously providing material for wastewater remediation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Silica fume reinforced polystyrene-based composite particles used as ultra-light weight proppants in hydraulic fracturing

NASA Astrophysics Data System (ADS)

Liang, Tian; Yan, Chunjie; Zhou, Sen; Zhang, Yonghan

2017-11-01

A new kind composite particle which could be utilized as ultra-light weight proppant was prepared via suspension polymerization in this work. The composite particles were composed of polystyrene and modified silica fume. This study indicated the composite particles had a bulk density (around 0.65 g cm-3) that is even lower than most of the commercial proppants. The pure polystyrene particles had a glass transition temperature of 130.3 °C and a crushing rate of 5.0% under the pressure of 52 MPa for 3 min. While the heat-treated composite particles had a higher glass transition temperature of 146.1 °C and a lower crushing rate of 1.0% under the same testing condition. In addition, the processes of synthesizing composite particles, procedures of heat treatment, effects of different incorporation amount and dispersion of modified silica fume in polymer matrix were systematically investigated.

Directed Self-Assembly on Photo-Crosslinked Polystyrene Sub-Layers: Nanopattern Uniformity and Orientation

PubMed Central

Koh, Haeng-Deog; Kim, Mi-Jeong

2016-01-01

A photo-crosslinked polystyrene (PS) thin film is investigated as a potential guiding sub-layer for polystyrene-block-poly (methyl methacrylate) block copolymer (BCP) cylindrical nanopattern formation via topographic directed self-assembly (DSA). When compared to a non-crosslinked PS brush sub-layer, the photo-crosslinked PS sub-layer provided longer correlation lengths of the BCP nanostructure, resulting in a highly uniform DSA nanopattern with a low number of BCP dislocation defects. Depending on the thickness of the sub-layer used, parallel or orthogonal orientations of DSA nanopattern arrays were obtained that covered the entire surface of patterned Si substrates, including both trench and mesa regions. The design of DSA sub-layers and guide patterns, such as hardening the sub-layer by photo-crosslinking, nano-structuring on mesas, the relation between trench/mesa width, and BCP equilibrium period, were explored with a view to developing defect-reduced DSA lithography technology. PMID:28773768

Removal of arsenic compounds from spent catecholated polymer

DOEpatents

Fish, Richard H.

1985-01-01

Described is a process for removing arsenic from petroliferous derived liquids by contacting said liquid at an elevated temperature with a divinylbenzene-crosslinked polystyrene having catechol ligands anchored thereon. Also, described is a process for regenerating spent catecholated polystyrene by removal of the arsenic bound to it from contacting petroliferous liquid as described above and involves: a. treating said spent catecholated polystyrene, at a temperature in the range of about 20.degree. to 100.degree. C. with an aqueous solution of at least one carbonate and/or bicarbonate of ammonium, alkali and alkaline earth metals, said solution having a pH between about 8 and 10 and, b. separating the solids and liquids from each other. Preferably the regeneration treatment is in two steps wherein step (a) is carried out with an aqueous alcoholic carbonate solution containing lower alkyl alcohol, and, steps (a) and (b) are repeated using a bicarbonate.

Removal of arsenic compounds from petroliferous liquids

DOEpatents

Fish, Richard H.

1985-01-01

Described is a process for removing arsenic from petroliferous derived liquids by contacting said liquid at an elevated temperature with a divinylbenzene-crosslinked polystyrene having catechol ligands anchored thereon. Also, described is a process for regenerating spent catecholated polystyrene by removal of the arsenic bound to it from contacting petroliferous liquid as described above and involves: a. treating said spent catecholated polystyrene, at a temperature in the range of about 20.degree. to 100.degree. C. with an aqueous solution of at least one carbonate and/or bicarbonate of ammonium, alkali and alkaline earth metals, said solution having a pH between about 8 and 10 and, b. separating the solids and liquids from each other. Preferably the regeneration treatment is in two steps wherein step (a) is carried out with an aqueous alcoholic carbonate solution containing lower alkyl alcohol, and, steps (a) and (b) are repeated using a bicarbonate.

Nanospot soldering polystyrene nanoparticles with an optical fiber probe laser irradiating a metallic AFM probe based on the near-field enhancement effect.

PubMed

Cui, Jianlei; Yang, Lijun; Wang, Yang; Mei, Xuesong; Wang, Wenjun; Hou, Chaojian

2015-02-04

With the development of nanoscience and nanotechnology for the bottom-up nanofabrication of nanostructures formed from polystyrene nanoparticles, joining technology is an essential step in the manufacturing and assembly of nanodevices and nanostructures in order to provide mechanical integration and connection. To study the nanospot welding of polystyrene nanoparticles, we propose a new nanospot-soldering method using the near-field enhancement effect of a metallic atomic force microscope (AFM) probe tip that is irradiated by an optical fiber probe laser. On the basis of our theoretical analysis of the near-field enhancement effect, we set up an experimental system for nanospot soldering; this approach is carried out by using an optical fiber probe laser to irradiate the AFM probe tip to sinter the nanoparticles, providing a promising technical approach for the application of nanosoldering in nanoscience and nanotechnology.

Methods for functionalization of microsized polystyrene beads with titania nanoparticles for cathodic electrophoretic deposition.

PubMed

Radice, S; Kern, P; Dietsch, H; Mischler, S; Michler, J

2008-02-15

Functionalization of colloidal particles based on the use of polyelectrolytes and heterocoagulation was combined with electrophoretic deposition (EPD), with the aim of depositing titania-polystyrene (TiO(2)-PS) composite particles on Ti6Al4V substrates. The composite particles were obtained by heterocoagulation of TiO(2) nanoparticles on the surface of monosized polystyrene beads of 4.6 microm in diameter. Two alternative methods were developed for the preparation of the TiO(2)-PS suspensions in organic fluids for cathodic electrodeposition. The first method was carried out in alkaline aqueous medium with the use of polyelectrolytes and intermediate control measurements of zeta potential, conductivity, and pH; the second one was carried out directly in the organic solvent used for EPD, typically isopropanol. Examples of deposits obtained by EPD in both suspensions and a comparative analysis between the two methods are presented.

Polymerization of styrene with cyclopentadienyl nickel complex/methylaluminoxane

NASA Astrophysics Data System (ADS)

Yu, Dongping; Zhang, Danfeng

2017-09-01

Polystyrene was synthesized by Cp(CH2CH2OCH3)NiCl(PPh3) in the presence of methylaluminoxane (MAO). This complex displayed a very high activity for styrene polymerization up to 107 g.mol-1Nih-1. 76.6% styrene was converted to polystyrene (PS) with an average molecular (Mn) of 1.13×105 at 50 °C in 30 min. The structure of the obtained polymer was characterized by 1H NMR and FT-IR.

Naval Arctic Research Laboratory (NARL) Subsurface Containment Berm Investigation

DTIC Science & Technology

2015-10-01

Southwest UTM Universal Transverse Mercator XPS Extruded Polystyrene WGS World Geodetic System ERDC/CRREL TR-15-15 1 1 Introduction In 1996, under...layers of extruded polystyrene (XPS) board insula- tion at approximately 1.0 m below the ground surface for the length of the berm. The XPS was...ply- wood installed during the trench construction. We attempted probing in Dew Line Road and in the area adjacent to the Navy Hangar and Treat- ment

Analysis and Design of a Photonic Biosensor for Mild Traumatic Brain Injury

DTIC Science & Technology

2013-03-01

well developed. The basic process involves hydration of dry lipid, cholesterol, protein, or other component of the lipid membrane onto a vessel...surface from organic solvent (e.g., chloroform), thereby producing a thin film of dry lipid. This material is then hydrated to solution typically in an...such as by reaction with a polystyrene plate . A nucleic acid molecule may be aminated to promote binding to a polystyrene section of a housing via the

Kelvin probe microscopic visualization of charge storage at polystyrene interfaces with pentacene and gold

NASA Astrophysics Data System (ADS)

Dawidczyk, T. J.; Johns, G. L.; Ozgun, R.; Alley, O.; Andreou, A. G.; Markovic, N.; Katz, H. E.

2012-02-01

Charge carriers trapped in polystyrene (PS) were investigated with Kelvin probe microscopy (KPM) and thermally stimulated discharge current (TSDC). Lateral heterojunctions of pentacene/PS were scanned using KPM, effectively observing polarization along a side view of a lateral nonvolatile organic field-effect transistor dielectric interface. TSDC was used to observe charge migration out of PS films and to estimate the trap energy level inside the PS, using the initial rise method.

Modeling of the phase equilibria of polystyrene in methylcyclohexane with semi-empirical quantum mechanical methods I.

PubMed

Wilczura-Wachnik, Hanna; Jónsdóttir, Svava Osk

2003-04-01

A method for calculating interaction parameters traditionally used in phase-equilibrium computations in low-molecular systems has been extended for the prediction of solvent activities of aromatic polymer solutions (polystyrene+methylcyclohexane). Using ethylbenzene as a model compound for the repeating unit of the polymer, the intermolecular interaction energies between the solvent molecule and the polymer were simulated. The semiempirical quantum chemical method AM1, and a method for sampling relevant internal orientations for a pair of molecules developed previously were used. Interaction energies are determined for three molecular pairs, the solvent and the model molecule, two solvent molecules and two model molecules, and used to calculated UNIQUAC interaction parameters, a(ij) and a(ji). Using these parameters, the solvent activities of the polystyrene 90,000 amu+methylcyclohexane system, and the total vapor pressures of the methylcyclohexane+ethylbenzene system were calculated. The latter system was compared to experimental data, giving qualitative agreement. Figure Solvent activities for the methylcylcohexane(1)+polystyrene(2) system at 316 K. Parameters aij (blue line) obtained with the AM1 method; parameters aij (pink line) from VLE data for the ethylbenzene+methylcyclohexane system. The abscissa is the polymer weight fraction defined as y2(x1)=(1mx1)M2/[x1M1+(1mx1)M2], where x1 is the solvent mole fraction and Mi are the molecular weights of the components.

One molecule of ionic liquid and tert-alcohol on a polystyrene-support as catalysts for efficient nucleophilic substitution including fluorination.

PubMed

Shinde, Sandip S; Patil, Sunil N

2014-12-07

The tert-alcohol and ionic liquid solvents in one molecule [mim-(t)OH][OMs] was immobilized on polystyrene and reported to be a highly efficient catalyst in aliphatic nucleophilic substitution using alkali metal salts. Herein, we investigated the catalytic activity of a new structurally modified polymer-supported tert-alcohol functionalized imidazolium salt catalyst in nucleophilic substitution of 2-(3-methanesulfonyloxypropyoxy)naphthalene as a model substrate with various metal nucleophiles. The tert-alcohol moiety of the ionic liquid with a hexyl chain distance from polystyrene had a better catalytic activity compared to the other resin which lacked an alkyl linker and tert-alcohol moiety. We found that the maximum [mim-(t)OH][OMs] loading had the best catalytic efficacy among the tested polystyrene-based ionic liquids (PSILs) in nucleophilic fluorination. The catalytic efficiency of the PS[him-(t)OH][OMs] as a phase transfer catalyst (PTC) was determined by carrying out various nucleophilic substitutions using the corresponding alkali metal salts from the third to sixth periodic in CH3CN or tert-BuOH media. The scope of this protocol with primary and secondary polar substrates containing many heteroatoms is also reported. This PS[him-(t)OH][OMs] catalyst not only enhances the reactivity of alkali metal salts and reduces the formation of by-products but also affords high yield with easy isolation.

Sorption of polycyclic aromatic hydrocarbons to polystyrene nanoplastic.

PubMed

Liu, Lijing; Fokkink, Remco; Koelmans, Albert A

2016-07-01

Microplastic has become an emerging contaminant of global concern. Bulk plastic can degrade to form smaller particles down to the nanoscale (<100 nm), which are referred to as nanoplastics. Because of their high surface area, nanoplastic may bind hydrophobic chemicals very effectively, increasing their hazard when such nanoplastics are taken up by biota. The present study reports distribution coefficients for sorption of polycyclic aromatic hydrocarbons (PAHs) to 70 nm polystyrene in freshwater, and PAH adsorption isotherms spanning environmentally realistic aqueous concentrations of 10(-5)  μg/L to 1 μg/L. Nanopolystyrene aggregate state was assessed using dynamic light scattering. The adsorption isotherms were nonlinear, and the distribution coefficients at the lower ends of the isotherms were very high, with values up to 10(9) L/kg. The high and nonlinear sorption was explained from π-π interactions between the planar PAHs and the surface of the aromatic polymer polystyrene and was higher than for micrometer-sized polystyrene. Reduction of nanopolystyrene aggregate sizes had no significant effect on sorption, which suggests that the PAHs could reach the sorption sites on the pristine nanoparticles regardless of the aggregation state. Pre-extraction of the nanopolystyrene with C18 polydimethylsiloxane decreased sorption of PAHs, which could be explained by removal of the most hydrophobic fraction of the nanopolystyrene. Environ Toxicol Chem 2016;35:1650-1655. © 2015 SETAC. © 2015 SETAC.

Tuning the pore composition by two simultaneous interfacial self-assembly processes: breath figures and coffee stain.

PubMed

de León, Alberto S; del Campo, Adolfo; Fernández-García, Marta; Rodríguez-Hernández, Juan; Muñoz-Bonilla, Alexandra

2014-06-03

In the current paper, we prepared microstructured porous films by the breath figures approach using polymer blends consisting of polystyrene as the major component and an amphiphilic additive, either a synthetic block copolymer {two different polystyrene-b-poly[poly(ethylene glycol) methyl ether methacrylate] copolymers} or a series of commercial surfactants. Tetrahydrofuran was employed as the solvent. Confocal micro-Raman spectroscopy demonstrated the preferential location of the amphiphilic additives in the cavities of the film as a consequence of the breath figures mechanism. However, the distribution of the copolymer within the cavities varies depending upon the structure and, more precisely, the surface properties of the additives, leading to three different situations. First of all, the copolymer with a larger polystyrene segment, insoluble in the condensed water droplets, is homogeneously distributed along the whole surface of the cavities. On the contrary, when the copolymer is soluble in water (shorter polystyrene segment), it migrates inside the droplet and a coffee-stain phenomenon takes place during the water droplet evaporation, conducting to a ring-like deposition on the top edge of the cavities. Finally, when a water-soluble surfactant with high surface activity is used, the surfactant is solubilized inside the water droplets, which provokes a decrease on the surface tension and the coffee-ring effect is modified. In this situation, the copolymer covers the bottom of the pore.

Polymeric particles conjugated with a ligand to VCAM-1 exhibit selective, avid, and focal adhesion to sites of atherosclerosis.

PubMed

Deosarkar, Sudhir P; Malgor, Ramiro; Fu, Jie; Kohn, Leonard D; Hanes, Justin; Goetz, Douglas J

2008-10-01

The increased expression of VCAM-1 on endothelial segments within plaque regions could be used as a target to deliver polymeric drug carriers selectively to sites of atherosclerosis. We probed the hypothesis that polymeric particles conjugated with a ligand for VCAM-1 exhibit selective and avid adhesion to sites of atherosclerosis. Particles made from polystyrene or the biodegradable polymer poly(sebacic acid)-block-polyethylene glycol (PSA-PEG) were conjugated with an antibody to VCAM-1 (alpha-VCAM-1) or IgG (negative control). The particles were injected into the jugular vein of ApoE(-/-) (a murine model of atherosclerosis) or wild type mice and their adhesion to the aorta determined. alpha-VCAM-1 particles exhibited significantly greater adhesion to ApoE(-/-) mouse aorta [32 +/- 5 (mean +/- SEM) particles/mm(2) for polystyrene particles and 31 +/- 7 particles/mm(2) for PSA-PEG particles] compared to the level of adhesion to wild type mouse aorta (18 +/- 1 particles/mm(2) for polystyrene particles and 6 +/- 1 particles/mm(2) for PSA-PEG particles). Within ApoE(-/-) mice, the alpha-VCAM-1 particles exhibited significantly greater adhesion to the aorta (32 +/- 5 particles/mm(2) for polystyrene particles and 31 +/- 7 particles/mm(2) for PSA-PEG particles) compared to the adhesion of IgG particles (1 +/- 1 particles/mm(2) for polystyrene particles and 2 +/- 1 particles/mm(2) for PSA-PEG particles). Detailed analysis of the adhesion revealed that alpha-VCAM-1 particles exhibited focal adhesion to plaque regions, in particular the periphery of the plaques, within the ApoE(-/-) mouse aorta. Combined the data demonstrate that polymeric particles conjugated with a ligand to VCAM-1 exhibit selective, avid and focal adhesion to sites of atherosclerosis providing strong evidence that VCAM-1 ligand bearing polymeric particles could be used for targeting drugs selectively to atherosclerotic tissue.

Clinical application of computer-designed polystyrene models in complex severe spinal deformities: a pilot study

PubMed Central

Mao, Keya; Xiao, Songhua; Liu, Zhengsheng; Zhang, Yonggang; Zhang, Xuesong; Wang, Zheng; Lu, Ning; Shourong, Zhu; Xifeng, Zhang; Geng, Cui; Baowei, Liu

2010-01-01

Surgical treatment of complex severe spinal deformity, involving a scoliosis Cobb angle of more than 90° and kyphosis or vertebral and rib deformity, is challenging. Preoperative two-dimensional images resulting from plain film radiography, computed tomography (CT) and magnetic resonance imaging provide limited morphometric information. Although the three-dimensional (3D) reconstruction CT with special software can view the stereo and rotate the spinal image on the screen, it cannot show the full-scale spine and cannot directly be used on the operation table. This study was conducted to investigate the application of computer-designed polystyrene models in the treatment of complex severe spinal deformity. The study involved 16 cases of complex severe spinal deformity treated in our hospital between 1 May 2004 and 31 December 2007; the mean ± SD preoperative scoliosis Cobb angle was 118° ± 27°. The CT scanning digital imaging and communication in medicine (DICOM) data sets of the affected spinal segments were collected for 3D digital reconstruction and rapid prototyping to prepare computer-designed polystyrene models, which were applied in the treatment of these cases. The computer-designed polystyrene models allowed 3D observation and measurement of the deformities directly, which helped the surgeon to perform morphological assessment and communicate with the patient and colleagues. Furthermore, the models also guided the choice and placement of pedicle screws. Moreover, the models were used to aid in virtual surgery and guide the actual surgical procedure. The mean ± SD postoperative scoliosis Cobb angle was 42° ± 32°, and no serious complications such as spinal cord or major vascular injury occurred. The use of computer-designed polystyrene models could provide more accurate morphometric information and facilitate surgical correction of complex severe spinal deformity. PMID:20213294

Variability of Listeria monocytogenes strains in biofilm formation on stainless steel and polystyrene materials and resistance to peracetic acid and quaternary ammonium compounds.

PubMed

Poimenidou, Sofia V; Chrysadakou, Marilena; Tzakoniati, Aikaterini; Bikouli, Vasiliki C; Nychas, George-John; Skandamis, Panagiotis N

2016-11-21

Listeria monocytogenes is a foodborne pathogen able to tolerate adverse conditions by forming biofilms or by deploying stress resistant mechanisms, and thus manages to survive for long periods in food processing plants. This study sought to investigate the correlation between biofilm forming ability, tolerance to disinfectants and cell surface characteristics of twelve L. monocytogenes strains. The following attributes were evaluated: (i) biofilm formation by crystal violet staining method on polystyrene, and by standard cell enumeration on stainless steel and polystyrene; (ii) hydrophobicity assay using solvents; (iii) minimum inhibitory concentration (MIC) and biofilm eradication concentration (BEC) of peracetic acid (PAA) and quaternary ammonium compounds (QACs), and (iv) resistance to sanitizers (PAA 2000ppm; QACs 500ppm) of biofilms on polystyrene and stainless steel. After 72h of incubation, higher biofilm levels were formed in TSB at 20°C, followed by TSB at 37°C (P=0.087) and diluted TSB 1/10 at both 20 (P=0.005) and 37°C (P=0.004). Cells grown at 30°C to the stationary phase had significant electron donating nature and a low hydrophobicity, while no significant correlation of cell surface properties to biofilm formation was observed. Strains differed in MIC PAA and BEC PAA by 24- and 15-fold, respectively, while a positive correlation between MIC PAA and BEC PAA was observed (P=0.02). The MIC QACs was positively correlated with the biofilm-forming ability on stainless steel (P=0.03). Regarding the impact of surface type, higher biofilm populations were enumerated on polystyrene than on stainless steel, which were also more tolerant to disinfectants. Among all strains, the greatest biofilm producer was a persistent strain with significant tolerance to QACs. These results may contribute to better understanding of L. monocytogenes behavior and survival on food processing surfaces. Copyright © 2016 Elsevier B.V. All rights reserved.

Effect of C-implantation on Nerve-Cell Attachment to Polystyrene Films

NASA Astrophysics Data System (ADS)

Sommani, Piyanuch; Tsuji, Hiroshi; Kitamura, Tsuyoshi; Hattori, Mitsutaka; Yamada, Tetsuya; Sato, Hiroko; Gotoh, Yasuhito; Ishikawa, Junzo

The surfaces of the polystyrene films spin-coated on glass were modified by carbon negative-ion implantation with various ion doses from 1×1014 to 3×1016 ions/cm2 at 5 and 10 keV. The implantation conditions with and without a pattering mask were for investigation of the cell-attachment properties and for evaluation of surface physical properties of contact angle, respectively. The contact angles of modified surface were investigated by pure water drop and air bubble method. The lowest angle value of the implanted films at 5 and 10 keV were approximately 72° at 3×1015 ions/cm2 after dipping in the de-ionized water for 2 hours. The lowering of contact angles on C-implanted surfaces when increase the ion dose is due to formation of the OH and C-O bonds. Nerve-cell-attachment properties of modified surface were investigated by the nerve-like cell of rat adrenal pheochromocytoma (PC12h) in vitro. After 2 days culture of the PC12h cells, no cells attached on the polystyrene films implanted with low ion dose from 1×1014 to 3×1014 ions/cm2. On the polystyrene films implanted with the dose order of 1015 ions/cm2, the cells selectively attached only on the implanted region. Whereas on the surfaces implanted with high dose such as 1×1016 and 3×1016 ions/cm2 mostly cells attached on the implanted region, and some attached on the unimplanted region, as well as cells were abnormal in shape and large size. Therefore, the suitable dose implantation for the selective-attachment of nerve-cells on the polystyrene films implanted at 5 and 10 keV were obtained around the dose order of 1015 ions/cm2, and the best condition for the selective attachment properties was at 3×1015 ions/cm2 corresponding to the lowest contact angle.

Evaluation of the environmental performance of alternatives for polystyrene production in Brazil.

PubMed

Hansen, Adriana Petrella; da Silva, Gil Anderi; Kulay, Luiz

2015-11-01

The global demand for polystyrene is supposed to reach an overall baseline of 23.5 million tons by 2020. The market has experienced the effects of such growth, especially regarding the environmental performance of the production processes. In Brazil, renewable assets have been used to overcome the adverse consequences of this expansion. This study evaluates this issue for the production of Brazilian polystyrene resins, general-purpose polystyrene (GPPS) and high-impact polystyrene (HIPS). The effects of replacing fossil ethylene with a biobased alternative are also investigated. Life Cycle Assessment is applied for ten scenarios, with different technological approaches for renewable ethylene production and an alternative for obtaining bioethanol, which considers the export of electricity. The fossil GPPS and HIPS show a better performance than the partially renewable sources in terms of Climate Change (CC), Terrestrial Acidification (TA), Photochemical Oxidant Formation (POF), and Water Depletion (WD). The exception is Fossil Depletion (FD), a somewhat predictable result. The main environmental loads associated with the renewable options are related to the sugarcane production. Polybutadiene fails to provide greater additional impact to HIPS when compared to GPPS. With regard to obtaining ethylene from ethanol, Adiabatic Dehydration (AD) technology consumes less sugarcane than Adiabatic Dehydration at High Pressure (ADHP), which leads to gains in TA and POF. In contrast, ADHP was more eco-friendly for WD because of its lower water losses and in terms of CC because of the advantageous balance of fossil CO2(eq) at the agricultural stage and the lower consumption of natural gas in ethylene production. The electricity export is an auspicious environmental opportunity because it can counterbalance some of the negative impacts associated with the renewable route. According to a "cradle-to-grave" perspective, the partially renewable resins show a more favorable balance of carbon. This difference increases when sequestration and biogenic carbon emissions are considered. Copyright © 2015 Elsevier B.V. All rights reserved.

Nucleation, crystallization, and melting of atactic polystyrene

NASA Astrophysics Data System (ADS)

Chai, Yu; Forrest, James

Here we present the study of using low molecular weight atactic polystyrene (aPS) as the model system to understand the nucleation, crystallization, and meting behaviors of the stereo-regular polymer chains in aPS. The result is consistent with the theoretical calculation proposed by Semenov. In addition, both the crystallization and melting experiments indicate that all crystals are on or near the surface. Finally, the nucleation experiment below the glass transition temperature provides another piece of evidence of the enhanced surface dynamics in glassy polymers.

Thermodynamic characteristics of the adsorption of 1,3,4-oxadiazoles and 1,2,4,5-tetrazines from methanol and water-methanol solutions onto hypercrosslinked polystyrene

NASA Astrophysics Data System (ADS)

Saifutdinov, B. R.; Davankov, V. A.; Il'in, M. M.

2017-03-01

The thermodynamic characteristics of the adsorption of several 1,3,4-oxadiazoles and 1,2,4,5- tetrazines from methanol and water-methanol solutions onto neutral hypercrosslinked polystyrene with a degree of crosslinking of 150% are determined via high performance liquid chromatography. It is shown how the obtained characteristics depend on the molecular structure of adsorbed substances and the composition of the liquid phase in which adsorption occurs.

Microcraters formed in glass by low density projectiles

NASA Technical Reports Server (NTRS)

Mandeville, J.-C.; Vedder, J. F.

1971-01-01

Microcraters were produced in soda-lime glass by the impact of low density projectiles of polystyrene (p = 1.06 g/cu cm) with masses between 0.7 and 62 picograms and velocities between 2 and 14 km/s. The morphology of the craters depended on the velocity and the angle of incidence of the projectiles and these are discussed in detail. It was found that the transitions in morphology of the craters formed by polystyrene spheres occurred at higher velocities than they did for more dense projectiles.

Fabrication and study of properties of magnetite nanoparticles in hybrid micelles of polystyrene-block-polyethylene oxide and sodium dodecyl sulfate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Loginova, T. P., E-mail: tlg@ineos.ac.ru; Timofeeva, G. I.; Lependina, O. L.

2016-01-15

Magnetite nanoparticles have been formed for the first time in hybrid micelles of polystyrene-block-polyethylene oxide and sodium dodecyl sulfate in water by ultrasonic treatment at room temperature. An analysis by small-angle X-ray scattering and transmission electron microscopy (TEM) showed that magnetite nanoparticles in hybrid micelles of block copolymer and sodium dodecyl sulfate are polydesperse (have sizes from 0.5 to 20 nm). The specific magnetization of solid samples has been measured.

Engineering Assessment of Big House at Summit Station, Greenland

DTIC Science & Technology

2011-04-01

Open cell expanded polystyrene insulation c EPS is not thought to be under the T-111 siding (communication 04 Nov 2010) d Quad-pane window ERDC...eastern side of the building where, in 2008, the roof access hatch was relocated. In 1999, the exterior was re-sheathed with 38- mm expanded ... polystyrene (EPS) insulation and 12.7-mm T-111 siding, which was attached with a number of fasteners. The wall thickness is 178 mm (Fig. 3). In 2006, a

SPH-4 U.S. Army Flight Helmet Performance 1972-1983

DTIC Science & Technology

1984-11-01

epoxy resin and fiberglass cloth. 2. Liner -Energy-absorbing 1.3 cm thick expanded polystyrene with a density of 0.08 gm/cm 3 3. Suspension - With...thick epoxy or polyester resin and fiberglass cloth layup provided in small, medium, and large siaeso b. Liner- Energy-absorbing 1.3 cm thick expanded ... polystyrene -foam with density of .08 gm/cu3. c ’ pension- Provided by three leather-covered foam pads located at the front, crown, and rear of the

Surface monolayers of well-defined amphiphilic block copolymer composed of poly(acrylic acid) or poly(oxyethylene) and poly(styrene). Interpolymer complexation at the air-water interface

DOE Office of Scientific and Technical Information (OSTI.GOV)

Niwa, Masazo; Hayashi, Takehiro; Higashi, Nobuyuki

1990-01-01

Amphiphilic block polymers (2,3) composed of poly(acrylic acid) (PAA) or poly(oxyethylene) (POE) and chain length controlled poly(styrene) (PSt) have been prepared by using a catalytic system of tribromomethyl-terminated oligomer and manganese carbonyl. All the amphiphilic materials formed well-behaved surface monolayers, and the II-A curves for them expanded systematically with an increase of the PSt chain length.

Novel cross-linked polystyrenes with large space network as tailor-made catalyst supports for sustainable media

DOE PAGES

Marrocchi, Assunta; Adriaensens, Peter; Bartollini, Elena; ...

2015-10-09

For a novel class of polystyrene-based gel-type resins (SPACeR, SP), containing the large 1,4-bis (4-vinylphenoxy)benzene cross-linker, is introduced; SP-immobilized 1,5,7-triazabicyclo [4.4.0]dec-5-ene (TBD) and triethylamine (TEA) bases are synthesized and characterized in terms of their structural, thermal and morphological features, and their catalytic efficiency in a series of fundamental chemical transformations under solvent-free conditions is investigated.

Polystyrene-based scintillator with pulse-shape discrimination capability

NASA Astrophysics Data System (ADS)

Zhmurin, P. N.; Lebedev, V. N.; Titskaya, V. D.; Adadurov, A. F.; Elyseev, D. A.; Pereymak, V. N.

2014-10-01

Polystyrene-based scintillators with 2-phenyl-5-(4-tert-butylephenyl)-1,3,4-oxadiazole (tert-BuPPD) or 2,5-di-(3-methylphenyl)-1,3,4 oxadiazole (m-DMePPD) are proposed for pulse-shape n/γ-discrimination. These scintillators have improved mechanical properties, long operational time and high n/γ discrimination parameter - figure of merit (1.49 and 1.81 in a wide energy region), so they can be used as detectors of fast neutrons in the presence of gamma radiation background.

The temperature dependence of inelastic light scattering from small particles for use in combustion diagnostic instrumentation

NASA Technical Reports Server (NTRS)

Cloud, Stanley D.

1987-01-01

A computer calculation of the expected angular distribution of coherent anti-Stokes Raman scattering (CARS) from micrometer size polystyrene spheres based on a Mie-type model, and a pilot experiment to test the feasibility of measuring CARS angular distributions from micrometer size polystyrene spheres by simply suspending them in water are discussed. The computer calculations predict a very interesting structure in the angular distributions that depends strongly on the size and relative refractive index of the spheres.

Highly ordered gold nanotubes using thiols at a cleavable block copolymer interface.

PubMed

Ryu, Ja-Hyoung; Park, Soojin; Kim, Bokyung; Klaikherd, Akamol; Russell, Thomas P; Thayumanavan, S

2009-07-29

We have prepared functionalized nanoporous thin films from a polystyrene-block-polyethylene oxide block copolymer, which was made cleavable due to the intervening disulfide bond. The cleavage reaction of the disulfide bond leaves behind free thiol groups inside the nanopores of polystyrene thin film. This nanoporous thin film can be used as a template for generating gold nanoring structures. This strategy can provide a facile method to form a highly ordered array of biopolymer or metal-polymer composite structures.

Sorption of adamantane phenylamide derivatives on hyper-cross-linked polystyrene from water-acetonitrile eluents

NASA Astrophysics Data System (ADS)

Shafigulin, R. V.; Konstantinov, A. V.; Bulanova, A. V.; Il'in, M. M.; Davankov, V. A.

2016-11-01

Study of the main physicochemical features of the sorption of phenylamide adamantane derivatives on hyper-cross-linked polystyrene from water-acetonitrile solutions shows that both hydrophobic and electronic interactions make a large contribution to retention, especially for a chlorine-containing derivative in which there are π- p and π- d interactions between the outer-shell electrons of the chlorine atom in addition to π- π interactions between aromatic fragments of the sorbate and sorbent.

Synthesis and characterization of polystyrene embolization particles doped with tantalum oxide nanoparticles for X-ray contrast.

PubMed

Morrison, Rachel; Thompson, James; Bird, Luke; Hill, Mark A; Townley, Helen

2015-08-01

Radiopaque and fluorescent embolic particles have been synthesized and characterised to match the size of vasculature found in tumours to ensure effective occlusion of the vessels. A literature search showed that the majority of vessels surrounding a tumour were less than 50 µm and therefore polydispersed polystyrene particles with a peak size of 50 µm have been synthesised. The embolic particles contain 5-8 nm amorphous tantalum oxide nanoparticles which provide X-ray contrast. Embolic particles containing up to 9.4 wt% tantalum oxide were prepared and showed significant contrast compared to the undoped polystyrene particles. The X-ray contrast of the embolic particles was shown to be linear (R(2) = 0.9) with respect to the concentration of incorporated tantalum nanoparticles. A model was developed which showed that seventy-five 50 µm embolic particles containing 10% tantalum oxide could provide the same contrast as 5 cm of bone. Therefore, the synthesized particles would provide sufficient X-ray contrast to enable visualisation within a tumour.

Investigation of the adsorption of polymer chains on amine-functionalized double-walled carbon nanotubes.

PubMed

Ansari, R; Ajori, S; Rouhi, S

2015-12-01

Molecular dynamics (MD) simulations were used to study the adsorption of different polymer chains on functionalized double-walled carbon nanotubes (DWCNTs). The nanotubes were functionalized with two different amines: NH2 (a small amine) and CH2-NH2 (a large amine). Considering three different polymer chains, all with the same number of atoms, the effect of polymer type on the polymer-nanotube interaction was studied. In general, it was found that covalent functionalization considerably improved the polymer-DWCNT interaction. By comparing the results obtained with different polymer chains, it was observed that, unlike polyethylene and polyketone, poly(styrene sulfonate) only weakly interacts with the functionalized DWCNTs. Accordingly, the smallest radius of gyration was obtained with adsorbed poly(styrene sulfonate). It was also observed that the DWCNTs functionalized with the large amine presented more stable interactions with polyketone and poly(styrene sulfonate) than with polyethylene, whereas the DWCNTs functionalized with the small amine showed better interfacial noncovalent bonding with polyethylene.

Negative dielectrophoresis spectroscopy for rare analyte quantification in biological samples

NASA Astrophysics Data System (ADS)

Kirmani, Syed Abdul Mannan; Gudagunti, Fleming Dackson; Velmanickam, Logeeshan; Nawarathna, Dharmakeerthi; Lima, Ivan T., Jr.

2017-03-01

We propose the use of negative dielectrophoresis (DEP) spectroscopy as a technique to improve the detection limit of rare analytes in biological samples. We observe a significant dependence of the negative DEP force on functionalized polystyrene beads at the edges of interdigitated electrodes with respect to the frequency of the electric field. We measured this velocity of repulsion for 0% and 0.8% conjugation of avidin with biotin functionalized polystyrene beads with our automated software through real-time image processing that monitors the Rayleigh scattering from the beads. A significant difference in the velocity of the beads was observed in the presence of as little as 80 molecules of avidin per biotin functionalized bead. This technology can be applied in the detection and quantification of rare analytes that can be useful in the diagnosis and the treatment of diseases, such as cancer and myocardial infarction, with the use of polystyrene beads functionalized with antibodies for the target biomarkers.

Polystyrene Foam Products Equation of State as a Function of Porosity and Fill Gas

NASA Astrophysics Data System (ADS)

Mulford, R. N.; Swift, D. C.

2009-12-01

An accurate EOS for polystyrene foam is necessary for analysis of numerous experiments in shock compression, inertial confinement fusion, and astrophysics. Plastic to gas ratios vary between various samples of foam, according to the density and cell-size of the foam. A matrix of compositions has been investigated, allowing prediction of foam response as a function of the plastic-to-air ratio. The EOS code CHEETAH allows participation of the air in the decomposition reaction of the foam. Differences between air-filled, Ar-blown, and CO2-blown foams are investigated, to estimate the importance of allowing air to react with products of polystyrene decomposition. O2-blown foams are included in some comparisons, to amplify any consequences of reaction with oxygen in air. He-blown foams are included in some comparisons, to provide an extremum of density. Product pressures are slightly higher for oxygen-containing fill gases than for non-oxygen-containing fill gases. Examination of product species indicates that CO2 decomposes at high temperatures.

A Facile Route for Patterned Growth of Metal-Insulator Carbon Lateral Junction through One-Pot Synthesis.

PubMed

Park, Beomjin; Park, Jaesung; Son, Jin Gyeong; Kim, Yong-Jin; Yu, Seong Uk; Park, Hyo Ju; Chae, Dong-Hun; Byun, Jinseok; Jeon, Gumhye; Huh, Sung; Lee, Seoung-Ki; Mishchenko, Artem; Hyun, Seung; Lee, Tae Geol; Han, Sang Woo; Ahn, Jong-Hyun; Lee, Zonghoon; Hwang, Chanyong; Novoselov, Konstantin S; Kim, Kwang S; Hong, Byung Hee; Kim, Jin Kon

2015-08-25

Precise graphene patterning is of critical importance for tailor-made and sophisticated two-dimensional nanoelectronic and optical devices. However, graphene-based heterostructures have been grown by delicate multistep chemical vapor deposition methods, limiting preparation of versatile heterostructures. Here, we report one-pot synthesis of graphene/amorphous carbon (a-C) heterostructures from a solid source of polystyrene via selective photo-cross-linking process. Graphene is successfully grown from neat polystyrene regions, while patterned cross-linked polystyrene regions turn into a-C because of a large difference in their thermal stability. Since the electrical resistance of a-C is at least 2 orders of magnitude higher than that for graphene, the charge transport in graphene/a-C heterostructure occurs through the graphene region. Measurement of the quantum Hall effect in graphene/a-C lateral heterostructures clearly confirms the reliable quality of graphene and well-defined graphene/a-C interface. The direct synthesis of patterned graphene from polymer pattern could be further exploited to prepare versatile heterostructures.

Assessment of biofilm formation by Scedosporium apiospermum, S. aurantiacum, S. minutisporum and Lomentospora prolificans.

PubMed

Mello, Thaís P; Aor, Ana Carolina; Gonçalves, Diego S; Seabra, Sergio H; Branquinha, Marta H; Santos, André L S

2016-08-01

Reported herein is the ability of Scedosporium apiospermum, S. aurantiacum, S. minutisporum and Lomentospora prolificans conidia to adhere, differentiate into hyphae and form biofilms on both polystyrene and lung epithelial cells. To different degrees, all of the fungi adhered to polystyrene after 4 h, with a predominance of those with germinated conidia. Prolonged fungi-polystyrene contact resulted in the formation of a monolayer of intertwined mycelia, which was identified as a typical biofilm structure due to the presence of a viable mycelial biomass, extracellular matrix and enhanced antifungal resistance. Ultrastructural details were revealed by SEM and CLSM, showing the dense compaction of the mycelial biomass and the presence of channels within the organized biofilm. A similar biofilm structure was observed following the co-culture of each fungus with A549 cells, revealing a mycelial trap covering all of the lung epithelial monolayer. Collectively, these results highlight the potential for biofilm formation by these clinically relevant fungal pathogens.

Determination of linear short chain aliphatic aldehyde and ketone vapors in air using a polystyrene-coated quartz crystal nanobalance sensor.

PubMed

Mirmohseni, Abdolreza; Olad, Ali

2010-01-01

A polystyrene coated quartz crystal nanobalance (QCN) sensor was developed for use in the determination of a number of linear short-chain aliphatic aldehyde and ketone vapors contained in air. The quartz crystal was modified by a thin-layer coating of a commercial grade general purpose polystyrene (GPPS) from Tabriz petrochemical company using a solution casting method. Determination was based on frequency shifts of the modified quartz crystal due to the adsorption of analytes at the surface of modified electrode in exposure to various concentrations of analytes. The frequency shift was found to have a linear relation to the concentration of analytes. Linear calibration curves were obtained for 7-70 mg l(-1) of analytes with correlation coefficients in the range of 0.9935-0.9989 and sensitivity factors in the range of 2.07-6.74 Hz/mg l(-1). A storage period of over three months showed no loss in the sensitivity and performance of the sensor.

Stability of Polymer Ultrathin Films (<7 nm) Made by a Top-Down Approach.

PubMed

Bal, Jayanta Kumar; Beuvier, Thomas; Unni, Aparna Beena; Chavez Panduro, Elvia Anabela; Vignaud, Guillaume; Delorme, Nicolas; Chebil, Mohamed Souheib; Grohens, Yves; Gibaud, Alain

2015-08-25

In polymer physics, the dewetting of spin-coated polystyrene ultrathin films on silicon remains mysterious. By adopting a simple top-down method based on good solvent rinsing, we are able to prepare flat polystyrene films with a controlled thickness ranging from 1.3 to 7.0 nm. Their stability was scrutinized after a classical annealing procedure above the glass transition temperature. Films were found to be stable on oxide-free silicon irrespective of film thickness, while they were unstable (<2.9 nm) and metastable (>2.9 nm) on 2 nm oxide-covered silicon substrates. The Lifshitz-van der Waals intermolecular theory that predicts the domains of stability as a function of the film thickness and of the substrate nature is now fully reconciled with our experimental observations. We surmise that this reconciliation is due to the good solvent rinsing procedure that removes the residual stress and/or the density variation of the polystyrene films inhibiting thermodynamically the dewetting on oxide-free silicon.

Patterned Well-Aligned ZnO Nanorods Assisted with Polystyrene Monolayer by Oxygen Plasma Treatment.

PubMed

Choi, Hyun Ji; Lee, Yong-Min; Yu, Jung-Hoon; Hwang, Ki-Hwan; Boo, Jin-Hyo

2016-08-05

Zinc oxide is known as a promising material for sensing devices due to its piezoelectric properties. In particular, the alignment of ZnO nanostructures into ordered nanoarrays is expected to improve the device sensitivity due to the large surface area which can be utilized to capture significant quantities of gas particles. However, ZnO nanorods are difficult to grow on the quartz substrate with well-ordered shape. So, we investigated nanostructures by adjusting the interval distance of the arranged ZnO nanorods using polystyrene (PS) spheres of various sizes (800 nm, 1300 nm and 1600 nm). In addition, oxygen plasma treatment was used to specify the nucleation site of round, patterned ZnO nanorod growth. Therefore, ZnO nanorods were grown on a quartz substrate with a patterned polystyrene monolayer by the hydrothermal method after oxygen plasma treatment. The obtained ZnO nanostructures were characterized by X-ray diffraction (XRD) and field-emission scanning electron microscope (FE-SEM).

Effect of Autoclaved Aerated Concrete Modification with High-Impact Polystyrene on Sound Insulation

NASA Astrophysics Data System (ADS)

Brelak, Sylwia; Dachowski, Ryszard

2017-10-01

Autoclaved aerated concrete is one of the most commonly used building materials. Its advantages include low density, high thermal insulation capacity and high fire resistance. It has a relatively high compressive strength, though not high enough to be able to compete with other building materials in this respect. One of the directions leading to the improvement of physical and mechanical properties of autoclaved aerated concrete is the modification of its composition. A noticeable effect of pulverized high-impact polystyrene (improved compressive strength and water absorption) was relevant for the decision to continue the study of its effects. This paper discusses the effect of high-impact polystyrene on sound insulation in AAC products. The tests demonstrated a positive influence of the modifier on AAC sound insulation enhancement. Results from the tests performed on HIPS-modified AAC products were showed and compared with the properties of conventional products. The effect of the polymer on the microstructure of the products obtained was described briefly.

PSBinder: A Web Service for Predicting Polystyrene Surface-Binding Peptides.

PubMed

Li, Ning; Kang, Juanjuan; Jiang, Lixu; He, Bifang; Lin, Hao; Huang, Jian

2017-01-01

Polystyrene surface-binding peptides (PSBPs) are useful as affinity tags to build a highly effective ELISA system. However, they are also a quite common type of target-unrelated peptides (TUPs) in the panning of phage-displayed random peptide library. As TUP, PSBP will mislead the analysis of panning results if not identified. Therefore, it is necessary to find a way to quickly and easily foretell if a peptide is likely to be a PSBP or not. In this paper, we describe PSBinder, a predictor based on SVM. To our knowledge, it is the first web server for predicting PSBP. The SVM model was built with the feature of optimized dipeptide composition and 87.02% (MCC = 0.74; AUC = 0.91) of peptides were correctly classified by fivefold cross-validation. PSBinder can be used to exclude highly possible PSBP from biopanning results or to find novel candidates for polystyrene affinity tags. Either way, it is valuable for biotechnology community.

Rear surface light emission measurements from laser-produced shock waves in clear and Al-coated polystyrene targets

NASA Astrophysics Data System (ADS)

McLean, E. A.; Deniz, A. V.; Schmitt, A. J.; Stamper, J. A.; Obenschain, S. P.; Lehecka, T.; Mostovych, A. N.; Seely, J.

1999-08-01

The Nike KrF laser, with its very uniform focal distributions, has been used at intensities near 10 14 W/cm 2 to launch shock waves in polystyrene targets. The rear surface visible light emission differed between clear polystyrene (CH) targets and targets with a thin (125 nm) Al coating on the rear side. The uncoated CH targets showed a relatively slowly rising emission followed by a sudden fall when the shock emerges, while the Al-coated targets showed a rapid rise in emission when the shock emerges followed by a slower fall, allowing an unambiguous determination of the time the shock arrived at the rear surface. A half-aluminized target allowed us to observe this difference in a single shot. The brightness temperature of both the aluminized targets and the non-aluminized targets was slightly below but close to rear surface temperature predictions of a hydrodynamic code. A discussion of preheat effects is given.

Boring crustaceans damage polystyrene floats under docks polluting marine waters with microplastic.

PubMed

Davidson, Timothy M

2012-09-01

Boring isopods damage expanded polystyrene floats under docks and, in the process, expel copious numbers of microplastic particles. This paper describes the impacts of boring isopods in aquaculture facilities and docks, quantifies and discusses the implications of these microplastics, and tests if an alternate foam type prevents boring. Floats from aquaculture facilities and docks were heavily damaged by thousands of isopods and their burrows. Multiple sites in Asia, Australia, Panama, and the USA exhibited evidence of isopod damage. One isopod creates thousands of microplastic particles when excavating a burrow; colonies can expel millions of particles. Microplastics similar in size to these particles may facilitate the spread of non-native species or be ingested by organisms causing physical or toxicological harm. Extruded polystyrene inhibited boring, suggesting this foam may prevent damage in the field. These results reveal boring isopods cause widespread damage to docks and are a novel source of microplastic pollution. Copyright © 2012 Elsevier Ltd. All rights reserved.

Moisture and Thermal Conductivity of Lightweight Block Walls

NASA Astrophysics Data System (ADS)

Joosep, R.

2015-11-01

This article examines thermal properties of lightweight block walls and their changes over the course of time. Three different types of lightweight blocks and two types of heat insulation are used in construction. Aeroc aerated concrete blocks are in use, as well as compacted LECA (Lightweight Expanded Clay Aggregate) Fibo blocks made from burned clay and Silbet blocks produced from oil shale ash. Expanded Thermisol EPS60F polystyrene plates and glass wool Isover OL-P plates are used for thermal insulation. The actual and computational values of thermal conductivity and the water draining properties of walls over time are compared in this article. Water draining from glass wool walls is relatively fast. Water-draining can take over a year in polystyrene insulated walls. All four wall constructions can be used as external walls, but care must be taken regarding the moisture content of the blocks during construction (the construction should be handled with care to minimise the moisture in the blocks), especially in polystyrene board-insulated walls.

Two-Dimensional Liquid Chromatography Analysis of Polystyrene/Polybutadiene Block Copolymers.

PubMed

Lee, Sanghoon; Choi, Heejae; Chang, Taihyun; Staal, Bastiaan

2018-05-15

A detailed characterization of a commercial polystyrene/polybutadiene block copolymer material (Styrolux) was carried out using two-dimensional liquid chromatography (2D-LC). The Styrolux is prepared by statistical linking reaction of two different polystyrene- block-polybutadienyl anion precursors with a multivalent linking agent. Therefore, it is a mixture of a number of branched block copolymers different in molecular weight, composition, and chain architecture. While individual LC analysis, including size exclusion chromatography, interaction chromatography, or liquid chromatography at critical condition, is not good enough to resolve all the polymer species, 2D-LC separations coupling two chromatography methods were able to resolve all polymer species present in the sample; at least 13 block copolymer species and a homopolystyrene blended. Four different 2D-LC analyses combining a different pair of two LC methods provide their characteristic separation results. The separation characteristics of the 2D-LC separations are compared to elucidate the elution characteristics of the block copolymer species.

Echicetin Coated Polystyrene Beads: A Novel Tool to Investigate GPIb-Specific Platelet Activation and Aggregation

PubMed Central

Petunin, Alexey; Clemetson, Kenneth J.; Gambaryan, Stepan; Walter, Ulrich

2014-01-01

von Willebrand factor/ristocetin (vWF/R) induces GPIb-dependent platelet agglutination and activation of αIIbβ3 integrin, which also binds vWF. These conditions make it difficult to investigate GPIb-specific signaling pathways in washed platelets. Here, we investigated the specific mechanisms of GPIb signaling using echicetin-coated polystyrene beads, which specifically activate GPIb. We compared platelet activation induced by echicetin beads to vWF/R. Human platelets were stimulated with polystyrene beads coated with increasing amounts of echicetin and platelet activation by echicetin beads was then investigated to reveal GPIb specific signaling. Echicetin beads induced αIIbβ3-dependent aggregation of washed platelets, while under the same conditions vWF/R treatment led only to αIIbβ3-independent platelet agglutination. The average distance between the echicetin molecules on the polystyrene beads must be less than 7 nm for full platelet activation, while the total amount of echicetin used for activation is not critical. Echicetin beads induced strong phosphorylation of several proteins including p38, ERK and PKB. Synergistic signaling via P2Y12 and thromboxane receptor through secreted ADP and TxA2, respectively, were important for echicetin bead triggered platelet activation. Activation of PKG by the NO/sGC/cGMP pathway inhibited echicetin bead-induced platelet aggregation. Echicetin-coated beads are powerful and reliable tools to study signaling in human platelets activated solely via GPIb and GPIb-triggered pathways. PMID:24705415

Structure and morphology of magnetron sputter deposited ultrathin ZnO films on confined polymeric template

NASA Astrophysics Data System (ADS)

Singh, Ajaib; Schipmann, Susanne; Mathur, Aakash; Pal, Dipayan; Sengupta, Amartya; Klemradt, Uwe; Chattopadhyay, Sudeshna

2017-08-01

The structure and morphology of ultra-thin zinc oxide (ZnO) films with different film thicknesses on confined polymer template were studied through X-ray reflectivity (XRR) and grazing incidence small angle X-ray scattering (GISAXS). Using magnetron sputter deposition technique ZnO thin films with different film thicknesses (<10 nm) were grown on confined polystyrene with ∼2Rg film thickness, where Rg ∼ 20 nm (Rg is the unperturbed radius of gyration of polystyrene, defined by Rg = 0.272 √M0, and M0 is the molecular weight of polystyrene). The detailed internal structure, along the surface/interfaces and the growth direction of the system were explored in this study, which provides insight into the growth procedure of ZnO on confined polymer and reveals that a thin layer of ZnO, with very low surface and interface roughness, can be grown by DC magnetron sputtering technique, with approximately full coverage (with bulk like electron density) even in nm order of thickness, in 2-7 nm range on confined polymer template, without disturbing the structure of the underneath template. The resulting ZnO-polystyrene hybrid systems show strong ZnO near band edge (NBE) and deep-level (DLE) emissions in their room temperature photoluminescence spectra, where the contribution of DLE gets relatively stronger with decreasing ZnO film thickness, indicating a significant enhancement of surface defects because of the greater surface to volume ratio in thinner films.

Development and evaluation of elastomeric materials for geothermal applications. Annual report, October 1977-December 1978

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mueller, W.A.; Kalfayan, S.H.; Reilly, W.W.

1979-05-15

The research involved formulation of commercially available materials and synthesis of new elastomers. Formulation studies at JPL and elsewhere produced a material having about 250-350 psi tensile strength and 30 to 80% elongation at 260/sup 0/C for at least 24 hours in simulated brine. The relationship between these laboratory test results and sealing performance in actual or simulated test conditions is not entirely clear; however, it is believed that no conventional formation or casing packer design is likely to perform well using these materials. The synthetic effort focused on high temperature block copolymers and development of curable polystyrene. Procedures weremore » worked out for synthesizing these new materials. Initial results with heat-cured unfilled polystyrene gum at 260/sup 0/C indicated a tensile strength of about 50 psi. Cast films of the first sample of polyphenyl quinoxaline-polystyrene block copolymer, which has a graft-block structure consisting of a polystyrene chain with pendant polyphenyl quinoxaline groups, showed elastomeric behavior in the required temperature range. Its tensile strength and elongation at 260/sup 0/C were 220 to 350 psi and 18 to 36%, respectively. All of these materials also showed satisfactory hydrolytic stability. A procedure for the synthesis of a linear block copolymer of this type has been devised, and the required new intermediates have been synthesized and characterized. A description of the previous year's work is included in an appendix.« less

Polymer supported gold nanoparticles: Synthesis and characterization of functionalized polystyrene-supported gold nanoparticles and their application in catalytic oxidation of alcohols in water

NASA Astrophysics Data System (ADS)

Kaboudin, Babak; Khanmohammadi, Hamid; Kazemi, Foad

2017-12-01

Sulfonated polystyrene microsphere were functionalized using ethylene diamine to introduce amine groups to the polymer chains. The amine functionalized polymers were used as a support for gold nanoparticles. A thorough structural characterization has been carried out by means of transmission electron microscopy (TEM), scanning electron microscopy (SEM) images, EDS, CHN and atomic absorption spectroscopy. The polymer supported gold nanoparticles was found to be an efficient catalyst for the oxidation of alcohols in water.

Novel nanoporous sorbent for solid-phase extraction in petroleum fingerprinting

NASA Astrophysics Data System (ADS)

Alayande, S. Oluwagbemiga; Hlengilizwe, Nyoni; Dare, E. Olugbenga; Msagati, Titus A. M.; Akinlabi, A. Kehinde; Aiyedun, P. O.

2016-04-01

Sample preparation is crucial in the analysis of petroleum and its derivatives. In this study, developing affordable sorbent for petroleum fingerprinting analysis using polymer waste such expanded polystyrene was explored. The potential of electrospun expanded polystyrene (EPS) as a sorbent for the solid-phase extraction (SPE) technique was investigated, and its efficiency was compared with commercial cartridges such as alumina, silica and alumina/silica hybrid commercial for petroleum fingerprinting analysis. The chromatograms showed that the packed electrospun EPS fibre demonstrated excellent properties for SPE applications relative to the hybrid cartridges.

Circularly polarized luminescence of syndiotactic polystyrene

NASA Astrophysics Data System (ADS)

Rizzo, Paola; Abbate, Sergio; Longhi, Giovanna; Guerra, Gaetano

2017-11-01

Syndiotactic polystyrene (s-PS) films, when crystallized from the amorphous state by temporary sorption of non-racemic guest molecules (like carvone) not only exhibit unusually high optical activity, both in the UV-Visible and Infrared ranges, but also present circularly polarized luminescence (CPL) with high dissymmetry ratios (g = ΔI/I values in the range 0.02-0.03). Experimental evidences provide support, rather than to the usual molecular circular dichroism, to a supramolecular chiral optical response being extrinsic to the site of photon absorption and emission, possibly associated with a helical morphology of s-PS crystallites.

Fluorescence from polystyrene - Photochemical processes in polymeric systems, 7

NASA Technical Reports Server (NTRS)

Gupta, M. C.; Gupta, A.

1983-01-01

Results are presented for measurements of the fluorescence spectra of polystyrene in dilute solution and in pure solid films. It is determined that a major potential source of experimental error is the concurrent photooxidative degradation in air which may obscure fluorescence emission from monomeric sites in solid films at 25 C. The fluorescence spectra of oriented films are evaluated in terms of the monomer to excimer fluorescence intensity ratio and the excimer 'red shift'. The monomer to excimer fluorescence intensity ratio is determined to be significantly higher in fluid solution than in solid film.

Binding and orientation of fibronectin on polystyrene surfaces using immobilized bacterial adhesin-related peptides.

PubMed

Klueh, U; Bryers, J D; Kreutzer, D L

2003-10-01

Fibronectin (FN) is known to bind to bacteria via high affinity receptors on bacterial surfaces known as adhesins. The binding of bacteria to FN is thought to have a key role in foreign device associated infections. For example, previous studies have indicated that Staphylococcus aureus adhesins bind to the 29 kDa NH(3) terminus end of FN, and thereby promote bacteria adherence to surfaces. Recently, the peptide sequences within the S. aureus adhesin molecule that are responsible for FN binding have been identified. Based on these observations, we hypothesize that functional FN can be bound and specifically oriented on polystyrene surfaces using bacterial adhesin-related (BRP-A) peptide. We further hypothesize that monoclonal antibodies that react with specific epitopes on the FN can be used to quantify both FN binding and orientation on these surfaces. Based on this hypothesis, we initiated a systematic investigation of the binding and orientation of FN on polystyrene surfaces using BRP-A peptide. To test this hypothesis, the binding and orientation of the FN to immobilized BRP-A was quantified using (125)I-FN, and monoclonal antibodies. (125)I-FN was used to quantitate FN binding to peptide-coated polystyrene surfaces. The orientation of bound FN was demonstrated by the use of monoclonal antibodies, which are reactive with the amine (N) or carboxyl (C) termini of the FN. The results of our studies demonstrated that when the BRP-A peptide was used to bind FN to surfaces that: 1. functional FN was bound to the peptide; 2. anti-C terminus antibodies bound to the peptide FN; and 3. only limited binding of anti-N terminus antibodies to peptide-bound FN occurred. We believe that the data that indicate an enhanced binding of anti-C antibodies reactive to anti-N antibodies are a result of the FN binding in an oriented manner with the N termini of FN bound tightly to the BRP-A on the polystyrene surface. Copyright 2003 Wiley Periodicals, Inc. J Biomed Mater Res 67A: 36-43, 2003

Size-dependent proinflammatory effects of ultrafine polystyrene particles: a role for surface area and oxidative stress in the enhanced activity of ultrafines.

PubMed

Brown, D M; Wilson, M R; MacNee, W; Stone, V; Donaldson, K

2001-09-15

Studies into the effects of ultrafine particles in the lung have shown adverse effects considered to be due in part to the particle size. Air pollution particles (PM(10)) are associated with exacerbations of respiratory disease and deaths from cardiovascular causes in epidemiological studies and the ultrafine fraction of PM(10) has been hypothesized to play an important role. The aim of the present study was to investigate proinflammatory responses to various sizes of polystyrene particles as a simple model of particles of varying size including ultrafine. In the animal model, we demonstrated that there was a significantly greater neutrophil influx into the rat lung after instillation of 64-nm polystyrene particles compared with 202- and 535-nm particles and this was mirrored in other parameters of lung inflammation, such as increased protein and lactate dehydrogenase in bronchoalveolar lavage. When surface area instilled was plotted against inflammation, these two variables were directly proportional and the line passed through zero. This suggests that surface area drives inflammation in the short term and that ultrafine particles cause a greater inflammatory response because of the greater surface area they possess. In vitro, we measured the changes in intracellular calcium concentration in mono mac 6 cells in view of the potential role of calcium as a signaling molecule. Calcium changes after particle exposure may be important in leading to proinflammatory gene expression such as chemokines. We demonstrated that only ultrafine polystyrene particles induced a significant increase in cytosolic calcium ion concentration. Experiments using dichlorofluorescin diacetate demonstrated greater oxidant activity of the ultrafine particles, which may explain their activity in these assays. There were significant increases in IL-8 gene expression in A549 epithelial cells after treatment with the ultrafine particles but not particles of other sizes. These findings suggest that ultrafine particles composed of low-toxicity material such as polystyrene have proinflammatory activity as a consequence of their large surface area. This supports a role for such particles in the adverse health effects of PM(10). Copyright 2001 Academic Press.

Polydispersity effects in poly(isoprene-b-styrene-b-ethylene oxide) triblock terpolymers

NASA Astrophysics Data System (ADS)

Meuler, Adam J.; Ellison, Christopher J.; Qin, Jian; Evans, Christopher M.; Hillmyer, Marc A.; Bates, Frank S.

2009-06-01

Four hydroxyl-terminated poly(isoprene-b-styrene) diblock copolymers with comparable molecular weights and compositions (equivalent volume fractions of polyisoprene and polystyrene) but different polystyrene block polydispersity indices (Mw/Mn=1.06,1.16,1.31,1.44) were synthesized by anionic polymerization using either sec-butyllithium or the functional organolithium 3-triisopropylsilyloxy-1-propyllithium. Poly(ethylene oxide) (PEO) blocks were grown from the end of each of these parent diblocks to yield four series of poly(isoprene-b-styrene-b-ethylene oxide) (ISO) triblock terpolymers that were used to interrogate the effects of varying the polydispersity of the middle bridged polystyrene block. In addition to the neat triblock samples, 13 multicomponent blends were prepared at four different compositions from the ISO materials containing a polystyrene segment with Mw/Mn=1.06; these blends were used to probe the effects of increasing the polydispersity of the terminal PEO block. The melt-phase behavior of all samples was characterized using small-angle X-ray scattering and dynamic mechanical spectroscopy. Numerous polydispersity-driven morphological transitions are reported, including transitions from lamellae to core-shell gyroid, from core-shell gyroid to hexagonally packed cylinders, and from network morphologies [either O70 (the orthorhombic Fddd network) or core-shell gyroid] to lamellae. Domain periodicities and order-disorder transition temperatures also vary with block polydispersities. Self-consistent field theory calculations were performed to supplement the experimental investigations and help elucidate the molecular factors underlying the polydispersity effects. The consequences of varying the polydispersity of the terminal PEO block are comparable to the polydispersity effects previously reported in AB diblock copolymers. Namely, domain periodicities increase with increasing polydispersity and domain interfaces tend to curve toward polydisperse blocks. The changes in phase behavior that are associated with variations in the polydispersity of the middle bridged polystyrene block, however, are not analogous to those reported in AB diblock copolymers, as increases in this middle block polydispersity are not always accompanied by (i) increased domain periodicities and (ii) a tendency for domain interfaces to curve toward the polydisperse domain. These results highlight the utility of polydispersity as a tool to tune the phase behavior of ABC block terpolymers.

Thermodynamic Interactions between Polystyrene and Long-Chain Poly(n-Alkyl Acrylates) Derived from Plant Oils.

PubMed

Wang, Shu; Robertson, Megan L

2015-06-10

Vegetable oils and their fatty acids are promising sources for the derivation of polymers. Long-chain poly(n-alkyl acrylates) and poly(n-alkyl methacrylates) are readily derived from fatty acids through conversion of the carboxylic acid end-group to an acrylate or methacrylate group. The resulting polymers contain long alkyl side-chains with around 10-22 carbon atoms. Regardless of the monomer source, the presence of alkyl side-chains in poly(n-alkyl acrylates) and poly(n-alkyl methacrylates) provides a convenient mechanism for tuning their physical properties. The development of structured multicomponent materials, including block copolymers and blends, containing poly(n-alkyl acrylates) and poly(n-alkyl methacrylates) requires knowledge of the thermodynamic interactions governing their self-assembly, typically described by the Flory-Huggins interaction parameter χ. We have investigated the χ parameter between polystyrene and long-chain poly(n-alkyl acrylate) homopolymers and copolymers: specifically we have included poly(stearyl acrylate), poly(lauryl acrylate), and their random copolymers. Lauryl and stearyl acrylate were chosen as model alkyl acrylates derived from vegetable oils and have alkyl side-chain lengths of 12 and 18 carbon atoms, respectively. Polystyrene is included in this study as a model petroleum-sourced polymer, which has wide applicability in commercially relevant multicomponent polymeric materials. Two independent methods were employed to measure the χ parameter: cloud point measurements on binary blends and characterization of the order-disorder transition of triblock copolymers, which were in relatively good agreement with one another. The χ parameter was found to be independent of the alkyl side-chain length (n) for large values of n (i.e., n > 10). This behavior is in stark contrast to the n-dependence of the χ parameter predicted from solubility parameter theory. Our study complements prior work investigating the interactions between polystyrene and short-chain polyacrylates (n ≤ 10). To our knowledge, this is the first study to explore the thermodynamic interactions between polystyrene and long-chain poly(n-alkyl acrylates) with n > 10. This work lays the groundwork for the development of multicomponent structured systems (i.e., blends and copolymers) in this class of sustainable materials.

A simple optical tweezers for trapping polystyrene particles

NASA Astrophysics Data System (ADS)

Shiddiq, Minarni; Nasir, Zulfa; Yogasari, Dwiyana

2013-09-01

Optical tweezers is an optical trap. For decades, it has become an optical tool that can trap and manipulate any particle from the very small size like DNA to the big one like bacteria. The trapping force comes from the radiation pressure of laser light which is focused to a group of particles. Optical tweezers has been used in many research areas such as atomic physics, medical physics, biophysics, and chemistry. Here, a simple optical tweezers has been constructed using a modified Leybold laboratory optical microscope. The ocular lens of the microscope has been removed for laser light and digital camera accesses. A laser light from a Coherent diode laser with wavelength λ = 830 nm and power 50 mW is sent through an immersion oil objective lens with magnification 100 × and NA 1.25 to a cell made from microscope slides containing polystyrene particles. Polystyrene particles with size 3 μm and 10 μm are used. A CMOS Thorlabs camera type DCC1545M with USB Interface and Thorlabs camera lens 35 mm are connected to a desktop and used to monitor the trapping and measure the stiffness of the trap. The camera is accompanied by camera software which makes able for the user to capture and save images. The images are analyzed using ImageJ and Scion macro. The polystyrene particles have been trapped successfully. The stiffness of the trap depends on the size of the particles and the power of the laser. The stiffness increases linearly with power and decreases as the particle size larger.

Dynamics of ultra-thin polystyrene with and without a (artificial) dead layer studied by resonance enhanced dynamic light scattering

NASA Astrophysics Data System (ADS)

Vianna, S. D. B.; Lin, F. Y.; Plum, M. A.; Duran, H.; Steffen, W.

2017-05-01

Using non-invasive, marker-free resonance enhanced dynamic light scattering, the dynamics of capillary waves on ultrathin polystyrene films' coupling to the viscoelastic and mechanical properties have been studied. The dynamics of ultrathin polymer films is still debated. In particular the question of what influence either the solid substrate and/or the fluid-gas interface has on the dynamics and the mechanical properties of films of glass forming liquids as polymers is in the focus of the present research. As a consequence, e.g., viscosity close to interfaces and thus the average viscosity of very thin films are prone to change. This study is focused on atactic, non-entangled polystyrene thin films on the gold surface. A slow dynamic mode was observed with Vogel-Fulcher-Tammann temperature dependence, slowing down with decreasing film thickness. We tentatively attribute this relaxation mode to overdamped capillary waves because of its temperature dependence and the dispersion with a wave vector which was found. No signs of a more mobile layer at the air/polymer interface or of a "dead layer" at the solid/polymer interface were found. Therefore we investigated the influence of an artificially created dead layer on the capillary wave dynamics by introducing covalently bound polystyrene polymer brushes as anchors. The dynamics was slowed down to a degree more than expected from theoretical work on the increase of density close to the solid liquid interface—instead of a "dead layer" of 2 nm, the interaction seems to extend more than 10 nm into the polymer.

Performance of polyethylene based radiation grafted anion exchange membrane with polystyrene-b-poly (ethylene/butylene)-b-polystyrene based ionomer using NiCo2O4 catalyst for water electrolysis

NASA Astrophysics Data System (ADS)

Gupta, Gaurav; Scott, Keith; Mamlouk, Mohamed

2018-01-01

A soluble anion exchange ionomer with high OH- ion conductivity comparable to that of H+ conductivity of Nafion is synthesised by chloromethylation of polystyrene-b-poly (ethylene/butylene)-b-polystyrene (SEBS) and used with NiCo2O4 electro-catalyst for water electrolysis. The ionomer has an ion exchange capacity of 1.9 mmol g-1 and ionic conductivity of 0.14 S cm-2 at 50 °C. The cell voltage at 20 °C at 100 mA cm-2 is 1.77 and 1.72 V in, 0.1 and 1.0 M NaOH, respectively, for an optimum loading of 10 mg cm-2 NiCo2O4. At 10 mg cm-2 NiCo2O4 electrolyser cell performance is at least equal to or superior to that of IrO2 at 2 mg cm-2 with excellent stability over 1 h. When the catalyst is sprayed on the GDL instead of CCM, the performance is further improved to 1.65 V at 100 mA cm-2 at 60 °C & 0.1 M KOH. The limited AEM electrolyser performance when operating with deionised water in comparison to PEM and alkaline electrolyser arises from the sluggish OER in the AEM environment equivalent to pH of 11.5 and the two orders of magnitude lower HER activity with respect to acid medium combined with the high Tafel slope of 120 mV dec-1.

Imidazolium-Based Polymeric Materials as Alkaline Anion-Exchange Fuel Cell Membranes

NASA Technical Reports Server (NTRS)

Narayan, Sri R.; Yen, Shiao-Ping S.; Reddy, Prakash V.; Nair, Nanditha

2012-01-01

Polymer electrolyte membranes that conduct hydroxide ions have potential use in fuel cells. A variety of polystyrene-based quaternary ammonium hydroxides have been reported as anion exchange fuel cell membranes. However, the hydrolytic stability and conductivity of the commercially available membranes are not adequate to meet the requirements of fuel cell applications. When compared with commercially available membranes, polystyrene-imidazolium alkaline membrane electrolytes are more stable and more highly conducting. At the time of this reporting, this has been the first such usage for imidazolium-based polymeric materials for fuel cells. Imidazolium salts are known to be electrochemically stable over wide potential ranges. By controlling the relative ratio of imidazolium groups in polystyrene-imidazolium salts, their physiochemical properties could be modulated. Alkaline anion exchange membranes based on polystyrene-imidazolium hydroxide materials have been developed. The first step was to synthesize the poly(styrene-co-(1-((4-vinyl)methyl)-3- methylimidazolium) chloride through a free-radical polymerization. Casting of this material followed by in situ treatment of the membranes with sodium hydroxide solutions provided the corresponding hydroxide salts. Various ratios of the monomers 4-chloromoethylvinylbenzine (CMVB) and vinylbenzine (VB) provided various compositions of the polymer. The preferred material, due to the relative ease of casting the film, and its relatively low hygroscopic nature, was a 2:1 ratio of CMVB to VB. Testing confirmed that at room temperature, the new membranes outperformed commercially available membranes by a large margin. With fuel cells now in use at NASA and in transportation, and with defense potential, any improvement to fuel cell efficiency is a significant development.

Polystyrene foam products equation of state as a function of porosity and fill gas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mulford, Roberta N; Swift, Damian C

2009-01-01

An accurate EOS for polystyrene foam is necessary for analysis of numerous experiments in shock compression, inertial confinement fusion, and astrophysics. Plastic to gas ratios vary between various samples of foam, according to the density and cell-size of the foam. A matrix of compositions has been investigated, allowing prediction of foam response as a function of the plastic-to-air ratio. The EOS code CHEETAH allows participation of the air in the decomposition reaction of the foam. Differences between air-filled, Ar-blown, and CO{sub 2}-blown foams are investigated, to estimate the importance of allowing air to react with products of polystyrene decomposition. O{submore » 2}-blown foams are included in some comparisons, to amplify any consequences of reaction with oxygen in air. He-blown foams are included in some comparisons, to provide an extremum of density. Product pressures are slightly higher for oxygen-containing fill gases than for non-oxygen-containing fill gases. Examination of product species indicates that CO{sub 2} decomposes at high temperatures.« less

Improvement of light extraction of LYSO scintillator by using a combination of self-assembly of nanospheres and atomic layer deposition.

PubMed

Zhu, Zhichao; Liu, Bo; Zhang, Haifeng; Ren, Weina; Cheng, Chuanwei; Wu, Shuang; Gu, Mu; Chen, Hong

2015-03-23

The self-assembled monolayer periodic array of polystyrene spheres conformally coated with TiO₂ layer using atomic layer deposition is designed to obtain a further enhancement of light extraction for LYSO scintillator. The maximum enhancement is 149% for the sample with polystyrene spheres conformally coated with TiO₂ layer, while the enhancement is only 76% for the sample with only polystyrene spheres. Such further enhancement could be contributed from the additional modes forming by TiO₂ layer due to its high refractive index, which can be approved by the simulation of electric field distribution. The experimental results are agreement with the simulated results. Furthermore, the prepared structured layer exhibits an excellent combination with the surface of scintillator, which is in favor of the practical application. Therefore, it is safely concluded that the combination of self-assembly method and atomic layer deposition is a promising approach to obtain a significant enhancement of light extraction for a large area. This method can be extended to many other luminescent materials and devices.

Optical properties of ordered ZnO/Ag thin films on polystyrene spheres

NASA Astrophysics Data System (ADS)

Li, Xiu; Chen, Xiuyan; Xin, Zhiqing; Li, Luhai; Xu, Yanfang

2017-08-01

A thorough research of the optical properties of ZnO/Ag structures sputtered by RF on PS colloidal crystal molds with different diameters is reported. The influences of the period of the substrates on the performance of ZnO thin films were studied. The results of scanning electron microscopic, X-ray diffraction patterns and UV-vis absorption spectroscopy indicated that the ZnO/Ag thin films were well-covering on PS colloidal crystal molds. The diameter of the polystyrene particles significantly influenced the PL spectrum intensity of ZnO/Ag by affecting the interferences of light. After adding PS colloidal crystal molds with different diameters, all the samples show two luminescent regions, namely a strong, narrow UV emission peak and a wide, weak visible emission band. However, the signal of UV emission increases more significantly. In particular, the maximum enhancement occurs when the diameter is 300 nm. This work proposes an effective way to improve ZnO light emission based on a simple, rapid and cost effective method to fabricate ordered periodic substrates by preparing single layer polystyrene microspheres masks.

Preparation of a thermoresponsive polymer grafted polystyrene monolithic capillary for the separation of bioactive compounds.

PubMed

Koriyama, Takuya; Asoh, Taka-Aki; Kikuchi, Akihiko

2016-11-01

To develop aqueous microseparation columns for bioactive compounds, a thermoresponsive polymer grafted polymer monolith was prepared inside silica capillaries having an I.D. of 100μm by polymerization of styrene (St) with m/p-divinylbenzene (DVB) in the presence of polydimethylsiloxane as porogen, followed by surface-initiated atom transfer radical polymerization (SI-ATRP) of N-isopropylacrylamide (NIPAAm). SEM analysis indicated that the resulting poly(N-isopropylacrylamide) (PNIPAAm) grafted polystyrene monolith had a consecutive three-dimensionally interconnected structure and through-pores, similar to the base polystyrene (PSt) monolith. The elution behavior of steroids with different hydrophobicity was evaluated using micro-high-performance liquid chromatography in sole aqueous mobile phase. Temperature dependent interaction changes were observed between steroids and the PNIPAAm modified surfaces. Furthermore, the interaction between bioactive compounds and the PNIPAAm grafted PSt surfaces was controlled and eventually separate these molecules with different hydrophobicities by simple temperature modulation in aqueous environment. The PNIPAAm grafted PSt monolithic capillary showed improved separation properties of bioactive compounds, compared with a PNIPAAm grafted hollow capillary in aqueous environment. Copyright © 2016 Elsevier B.V. All rights reserved.

Mass Transport Through Carbon Nanotube-Polystyrene Bundles

NASA Astrophysics Data System (ADS)

Lin, Rongzhou; Tran, Tuan

2016-05-01

Carbon nanotubes have been widely used as test channels to study nanofluidic transport, which has been found to have distinctive properties compared to transport of fluids in macroscopic channels. A long-standing challenge in the study of mass transport through carbon nanotubes (CNTs) is the determination of flow enhancement. Various experimental investigations have been conducted to measure the flow rate through CNTs, mainly based on either vertically aligned CNT membranes or individual CNTs. Here, we proposed an alternative approach that can be used to quantify the mass transport through CNTs. This is a simple method relying on the use of carbon nanotube-polystyrene bundles, which are made of CNTs pulled out from a vertically aligned CNT array and glued together by polystyrene. We experimentally showed by using fluorescent tagging that the composite bundles allowed measureable and selective mass transport through CNTs. This type of composite bundle may be useful in various CNT research areas as they are simple to fabricate, less likely to form macroscopic cracks, and offer a high density of CNT pores while maintaining the aligned morphology of CNTs.

Solution-Processed Donor-Acceptor Polymer Nanowire Network Semiconductors For High-Performance Field-Effect Transistors

PubMed Central

Lei, Yanlian; Deng, Ping; Li, Jun; Lin, Ming; Zhu, Furong; Ng, Tsz-Wai; Lee, Chun-Sing; Ong, Beng S.

2016-01-01

Organic field-effect transistors (OFETs) represent a low-cost transistor technology for creating next-generation large-area, flexible and ultra-low-cost electronics. Conjugated electron donor-acceptor (D-A) polymers have surfaced as ideal channel semiconductor candidates for OFETs. However, high-molecular weight (MW) D-A polymer semiconductors, which offer high field-effect mobility, generally suffer from processing complications due to limited solubility. Conversely, the readily soluble, low-MW D-A polymers give low mobility. We report herein a facile solution process which transformed a lower-MW, low-mobility diketopyrrolopyrrole-dithienylthieno[3,2-b]thiophene (I) into a high crystalline order and high-mobility semiconductor for OFETs applications. The process involved solution fabrication of a channel semiconductor film from a lower-MW (I) and polystyrene blends. With the help of cooperative shifting motion of polystyrene chain segments, (I) readily self-assembled and crystallized out in the polystyrene matrix as an interpenetrating, nanowire semiconductor network, providing significantly enhanced mobility (over 8 cm2V−1s−1), on/off ratio (107), and other desirable field-effect properties that meet impactful OFET application requirements. PMID:27091315

Subterranean Termite Resistance of Polystyrene-Treated Wood from Three Tropical Wood Species.

PubMed

Hadi, Yusuf Sudo; Massijaya, Muh Yusram; Arinana, A

2016-07-21

The objective of this work was to investigate the resistance of three Indonesian wood species to termite attack. Samples from sengon (Falcataria moluccana), mangium (Acacia mangium), and pine (Pinus merkusii) were treated with polystyrene at loading levels of 26.0%, 8.6%, and 7.7%, respectively. Treated and untreated samples were exposed to environmental conditions in the field for 3 months. Untreated specimens of sengon, mangium, and pine had resistance ratings of 3.0, 4.6, and 2.4, respectively, based on a 10-point scale from 0 (no resistance) to 10 (complete or near-complete resistance). Corresponding resistance values of 7.8, 7.2, and 8.2 were determined for specimens treated with polystyrene. Overall weight loss values of 50.3%, 23.3%, and 66.4% were found for untreated sengon, mangium, and pine samples, respectively; for treated samples, the values were 7.6%, 14.4%, and 5.1%, respectively. Based on the findings in this study, overall resistance to termite attack was higher for treated samples compared to untreated samples.

Binary particle separation in droplet microfluidics using acoustophoresis

NASA Astrophysics Data System (ADS)

Fornell, Anna; Cushing, Kevin; Nilsson, Johan; Tenje, Maria

2018-02-01

We show a method for separation of two particle species with different acoustic contrasts originally encapsulated in the same droplet in a continuous two-phase system. This was realized by using bulk acoustic standing waves in a 380 μm wide silicon-glass microfluidic channel. Polystyrene particles (positive acoustic contrast particles) and in-house synthesized polydimethylsiloxane (PDMS) particles (negative acoustic contrast particles) were encapsulated inside water-in-oil droplets either individually or in a mixture. At acoustic actuation of the system at the fundamental resonance frequency, the polystyrene particles were moved to the center of the droplet (pressure node), while the PDMS particles were moved to the sides of the droplet (pressure anti-nodes). The acoustic particle manipulation step was combined in series with a trifurcation droplet splitter, and as the original droplet passed through the splitter and was divided into three daughter droplets, the polystyrene particles were directed into the center daughter droplet, while the PDMS particles were directed into the two side daughter droplets. The presented method expands the droplet microfluidics tool-box and offers new possibilities to perform binary particle separation in droplet microfluidic systems.

Equilibrium and heat of adsorption of diethyl phthalate on heterogeneous adsorbents.

PubMed

Zhang, Weiming; Xu, Zhengwen; Pan, Bingcai; Hong, Changhong; Jia, Kun; Jiang, Peijuan; Zhang, Qingjian; Pan, Bingjun

2008-09-01

Removal of phthalate esters from water has been of considerable concern recently. In the present study, the adsorptive removal performance of diethyl phthalate (DEP) from water was investigated with the aminated polystyrene resin (NDA-101) and oxidized polystyrene resin (NDA-702). In addition, the commercial homogeneous polystyrene resin (XAD-4) and acrylic ester resin (Amberlite XAD-7) as well as coal-based granular activated carbon (AC-750) were chosen for comparison. The corresponding equilibrium isotherms are well described by the Freundlich equation and the adsorption capacities for DEP followed the order NDA-702 > NDA-101 > AC-750 > XAD-4 > XAD-7. Analysis of adsorption mechanisms suggested that these adsorbents spontaneously adsorb DEP molecules driven mainly by enthalpy change, and the adsorption process was derived by multiple adsorbent-adsorbate interactions such as hydrogen bonding, pi-pi stacking, and micropore filling. The information related to the adsorbent surface heterogeneity and the adsorbate-adsorbate interaction was obtained by Do's model. All the results indicate that heterogeneous resins NDA-702 and NDA-101 have excellent potential as an adsorption material for the removal of DEP from the contaminated water.

Subterranean Termite Resistance of Polystyrene-Treated Wood from Three Tropical Wood Species

PubMed Central

Hadi, Yusuf Sudo; Massijaya, Muh Yusram; Arinana, A.

2016-01-01

The objective of this work was to investigate the resistance of three Indonesian wood species to termite attack. Samples from sengon (Falcataria moluccana), mangium (Acacia mangium), and pine (Pinus merkusii) were treated with polystyrene at loading levels of 26.0%, 8.6%, and 7.7%, respectively. Treated and untreated samples were exposed to environmental conditions in the field for 3 months. Untreated specimens of sengon, mangium, and pine had resistance ratings of 3.0, 4.6, and 2.4, respectively, based on a 10-point scale from 0 (no resistance) to 10 (complete or near-complete resistance). Corresponding resistance values of 7.8, 7.2, and 8.2 were determined for specimens treated with polystyrene. Overall weight loss values of 50.3%, 23.3%, and 66.4% were found for untreated sengon, mangium, and pine samples, respectively; for treated samples, the values were 7.6%, 14.4%, and 5.1%, respectively. Based on the findings in this study, overall resistance to termite attack was higher for treated samples compared to untreated samples. PMID:27455331

Colitis induced by sodium polystyrene sulfonate in sorbitol: A report of six cases.

PubMed

Jacob, Sheba S K; Parameswaran, Ashok; Parameswaran, Sarojini Ashok; Dhus, Ubal

2016-03-01

Drug-related injury has been noted in virtually all organ systems, and recognition of the patterns of injury associated with medication enables modification of treatment and reduces the morbidity associated with the side effects of drugs. With the large number of new drugs being developed, documentation of the morphology of the changes seen as an adverse effect becomes important to characterize the pattern of injury. The pathologist is often the first to identify these abnormalities and correlate them with a particular drug. Kayexalate or sodium polystyrene sulfonate (SPS), a linear polymer derived from polystyrene containing sulfonic acid and sulfonate functional groups is used to treat hyperkalemia. It is usually administered with an osmotic laxative sorbitol orally or as retention enema. This combination has been implicated in causing damage to different parts of the gastrointestinal (GI) tract especially the colon and causes an established pattern of injury, recognizable by the presence of characteristic crystals, is presented to create a greater awareness of the Kayexalate colitis. This entity should be included in the differential diagnosis of lower GI mucosal injury in a setting of uremia and hyperkalemia.

Migration of mineral hydrocarbons into foods. 2. Polystyrene, ABS, and waxed paperboard containers for dairy products.

PubMed

Castle, L; Kelly, M; Gilbert, J

1993-01-01

Migration of mineral hydrocarbons into dairy products and sunflower oil (fatty food simulant) has been studied using a gas chromatographic procedure. The food contact materials examined were polystyrene and ABS pots and tubs, and waxed paperboard. Levels of mineral oil in the polystyrene and ABS articles ranged from 0.3 to 5.5% w/w (13 to 366 mg/dm2) and as a coating on the paperboard ranged from 1.0 to 7.7% (55 to 565 mg/dm2). Exposure conditions were 7 days at 4 degrees C for the dairy products and 10 days at 40 degrees C for the oil. However, individual serving milk and creams (UHT) were retail samples which were stored at ambient temperature before analysis. Migration into the milk products was less than 3 mg/kg. Transfer to sunflower oil simulant and into individual serving milk products was much higher at levels up to 150 mg/kg (2 mg/dm2) and 90 mg/kg (4 mg/dm2) for the oil and milk respectively.

Deuteron NMR (Nuclear Magnetic Resonance) in relation to the glass transition in polymers

NASA Technical Reports Server (NTRS)

Roessler, E.; Sillescu, H.; Spiess, H. W.; Wallwitz, R.

1983-01-01

H-2NMR is introduced as a tool for investigating slow molecular motion in the glass transition region of amorphous polymers. In particular, we compare H-2 spin alignment echo spectra of chain deuterated polystyrene with model calculations for restricted rotational Brownian motion. Molecular motion in the polyztyrene-toluene system has been investigated by analyzing H-2NMR of partially deuterated polystyrene and toluene, respectively. The diluent mobility in the mixed glass has been decomposed into solid and liquid components where the respective average correlation times differ by more than 5 decades.

Technology Solutions for Existing Homes Case Study: Trade-Friendly Retrofit Insulated Panels for Existing Buildings

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

For this project with the U.S. Department of Energy Building America team Home Innovation Research Labs, the retrofit insulated panels relied on an enhanced expanded polystyrene (EPS) for thermal resistance of R-4.5/inch, which is an improvement of 10% over conventional (white-colored) EPS. EPS, measured by its life cycle, is an alternative to commonly used extruded polystyrene and spray polyurethane foam. It is a closed-cell product made up of 90% air, and it requires about 85% fewer petroleum products for processing than other rigid foams.

Synthesis, characterization and catalytic activity of novel large network polystyrene-immobilized organic bases

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tassi, Marco; Bartollini, Elena; Adriaensens, Peter

2015-12-07

In view of searching for efficient polymeric supports for organic bases to be used in environmentally friendly reaction conditions, novel gel-type cross-linked polystyrenes functionalized with diethylamine and 1,5,7-triazabicyclo[4.4.0]dec-5-ene, have been prepared. Moreover, the structural properties and morphology of these catalysts have been determined by extensive solid state NMR experiments, FTIR spectroscopy and SEM/TEM microscopy. SPACeR-supported bases were found to exhibit high catalytic activity in the epoxide ring opening by phenols. Finally, a range of β-substituted alcohols have been readily and regioselectively synthesized.

Ileocolic perforation secondary to sodium polystyrene sulfonate in sorbitol use: A case report

PubMed Central

Trottier, Vincent; Drolet, Sébastien; Morcos, Mohib W

2009-01-01

Hyperkalemia is a common condition encountered in medical and surgical patients. It can lead to various complications including cardiac arrhythmias. Sodium polystyrene sulfonate (SPS) in sorbitol is an ion-exchange resin that can be used to treat hyperkalemia. It can be used in enema or in oral form. The present article describes the case of an intensive care unit patient who experienced severe, diffuse, intestinal perforation induced by the use of SPS-sorbitol, requiring multiple laparotomies, followed by a brief review of the relevant literature and recommendations regarding the use of SPS-sorbitol. PMID:19826644

Patterned Diblock Co-Polymer Thin Films as Templates for Advanced Anisotropic Metal Nanostructures.

PubMed

Roth, Stephan V; Santoro, Gonzalo; Risch, Johannes F H; Yu, Shun; Schwartzkopf, Matthias; Boese, Torsten; Döhrmann, Ralph; Zhang, Peng; Besner, Bastian; Bremer, Philipp; Rukser, Dieter; Rübhausen, Michael A; Terrill, Nick J; Staniec, Paul A; Yao, Yuan; Metwalli, Ezzeldin; Müller-Buschbaum, Peter

2015-06-17

We demonstrate glancing-angle deposition of gold on a nanostructured diblock copolymer, namely polystyrene-block-poly(methyl methacrylate) thin film. Exploiting the selective wetting of gold on the polystyrene block, we are able to fabricate directional hierarchical structures. We prove the asymmetric growth of the gold nanoparticles and are able to extract the different growth laws by in situ scattering methods. The optical anisotropy of these hierarchical hybrid materials is further probed by angular resolved spectroscopic methods. This approach enables us to tailor functional hierarchical layers in nanodevices, such as nanoantennae arrays, organic photovoltaics, and sensor electronics.

Creating biomimetic polymeric surfaces by photochemical attachment and patterning of dextran

PubMed Central

Ferrer, M. Carme Coll; Yang, Shu; Eckmann, David M.; Composto, Russell J.

2010-01-01

In this work, we report the preparation of photoactive dextran and demonstrate its utility by photochemically attaching it onto various polymeric substrates. The attachment of homogeneous and patterned dextran films was performed on polyurethane and polystyrene, with detailed analysis of surface morphology, swelling behavior, and the protein resistance of these substrates. The described photoactive dextran and attachment procedure is applicable to a wide variety of substrates while accommodating surfaces with complex surface and geometries. Dextran with azide content between 22 to 0.3 wt% was produced by esterification with p-azidobenzoic acid. Dextran (1.2 wt% azide) was photografted onto plasma oxidized polyurethane and polystyrene and displayed thicknesses of 5 ± 3 nm and 7 ± 3 nm, respectively. The patterned dextran on oxidized polyurethane was patchy with a nominal height difference between dextranized and non-dextranized regions. The azidated dextran on oxidized polystyrene exhibited a distinct step in height. In the presence of PBS buffer, the dextranized regions became smoother and more uniform without affecting the height difference at the oxidized polyurethane boundary. However, the dextranized regions on oxidized polyurethane were observed to swell by a factor of 3 relative to the dried thickness. These dissimilarities were attributed to hydrogen bonding between the dextran and oxidized polyurethane and were confirmed by the photoimmobiliization in the presence of LiCl. The resulting surface was the smoothest of all the azidated dextran samples (RRMS = 1 ± 0.3 nm) and swelled up to 2 times its dried thickness in PBS buffer. The antifouling properties of dextran functionalized surfaces were verified by the selective adsorption of FITC-labeled human albumin only on the non-dextranized regions of the patterned polyurethane and polystyrene substrates. PMID:20712352

Drug adsorption to plastic containers and retention of drugs in cultured cells under in vitro conditions.

PubMed

Palmgrén, Joni J; Mönkkönen, Jukka; Korjamo, Timo; Hassinen, Anssi; Auriola, Seppo

2006-11-01

Loss of drug content during cell culture transport experiment can lead to misinterpretations in permeability analysis. This study analyses drug adsorption to various plastic containers and drug retention in cultured cells under in vitro conditions. The loss of various drugs to polystyrene tubes and well plates was compared to polypropylene and glass tubes both in deionised water and buffer solution. In cellular uptake experiments, administered drugs were obtained from cultured cells by liquid extraction. Samples were collected at various time points and drug concentrations were measured by a new HPLC-MS/MS method. Acidic drugs (hydrochlorothiazide, naproxen, probenicid, and indomethacin) showed little if any sorption to all tested materials in either water or buffer. In the case of basic drugs, substantial loss to polystyrene tubes and well plates was observed. After 4.5 h, the relative amount remaining in aqueous test solution stored in polystyrene tubes was 64.7 +/- 6.8%, 38.4 +/- 9.1%, 31.9 +/- 6.7%, and 23.5 +/- 6.1% for metoprolol, medetomidine, propranolol, and midazolam, respectively. Interestingly, there was no significant loss of drugs dissolved in buffer to any of the tested materials indicating that buffer reduced surficial interaction. The effect of drug concentration to sorption was also tested. Results indicated that the higher the concentration in the test solution the lower the proportional drug loss, suggesting that the polystyrene contained a limited amount of binding sites. Cellular uptake studies showed considerable retention of drugs in cultured cells. The amounts of absorbed drugs in cellular structures were 0.45%, 4.88%, 13.15%, 43.80%, 23.57% and 11.22% for atenolol, metoprolol, medetomidine, propranolol, midazolam, and diazepam, respectively. Overall, these findings will benefit development and validation of further in vitro drug permeation experiments.

Stability of urine specimens stored with and without preservatives at room temperature and on ice prior to urinalysis.

PubMed

Ercan, Müjgan; Akbulut, Emiş Deniz; Abuşoğlu, Sedat; Yılmaz, Fatma Meriç; Oğuz, Esra Fırat; Topçuoğlu, Canan; Öztekin, Volkan; Boğdaycıoğlu, Nihal

2015-09-01

Laboratories determine the most appropriate approach for the collection and transport of urine specimens. We investigated the effect of a chlorhexidine-based preservative tube on sample stability, compared the results of refrigerated polystyrene tubes with no additives, and investigated the effect of temperature on the performance of preservative tubes. Fresh urine specimen (n=48) aliquots in BD Vacutainer® Plus Urinalysis Preservative Tubes and polystyrene tubes were analyzed on an Iris Diagnostics iQ200. Samples in polystyrene tubes were refrigerated for 4 and 8h. Four aliquots in preservative tubes were kept at room temperature for 4, 8, 24, and 72h, while two aliquots were kept on ice for 4 and 8h. There was good agreement for all chemistry and microscopy parameters with the exceptions of white blood cells (WBCs) at 24 and 72h and red blood cells (RBCs) at 72h. Preservative tubes on ice showed a significant decrease in concordance of WBCs and calcium oxalate (CaOx) parameters compared with the results at room temperature. Results of refrigerated polystyrene tubes showed good agreement with the exceptions of WBC clumps and amorphous crystal at 8h. A chlorhexidine-containing preservative tube seems advantageous for urine sample transport from outside healthcare services. A preservative tube offers comparable results with urine samples kept in a refrigerator for 4-8h for the majority of parameters. Keeping samples at room temperature is recommended when preservative tubes are used because ice produces a negative effect on WBCs and CaOx. Copyright © 2015 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

Comparative analysis of biofilm formation by Bacillus cereus reference strains and undomesticated food isolates and the effect of free iron.

PubMed

Hayrapetyan, Hasmik; Muller, Lisette; Tempelaars, Marcel; Abee, Tjakko; Nierop Groot, Masja

2015-05-04

Biofilm formation of Bacillus cereus reference strains ATCC 14579 and ATCC 10987 and 21 undomesticated food isolates was studied on polystyrene and stainless steel as contact surfaces. For all strains, the biofilm forming capacity was significantly enhanced when in contact with stainless steel (SS) as a surface as compared to polystyrene (PS). For a selection of strains, the total CFU and spore counts in biofilms were determined and showed a good correlation between CFU counts and total biomass of these biofilms. Sporulation was favoured in the biofilm over the planktonic state. To substantiate whether iron availability could affect B. cereus biofilm formation, the free iron availability was varied in BHI by either the addition of FeCl3 or by depletion of iron with the scavenger 2,2-Bipyridine. Addition of iron resulted in increased air-liquid interface biofilm on polystyrene but not on SS for strain ATCC 10987, while the presence of Bipyridine reduced biofilm formation for both materials. Biofilm formation was restored when excess FeCl3 was added in combination with the scavenger. Further validation of the iron effect for all 23 strains in microtiter plate showed that fourteen strains (including ATCC10987) formed a biofilm on PS. For eight of these strains biofilm formation was enhanced in the presence of added iron and for eleven strains it was reduced when free iron was scavenged. Our results show that stainless steel as a contact material provides more favourable conditions for B. cereus biofilm formation and maturation compared to polystyrene. This effect could possibly be linked to iron availability as we show that free iron availability affects B. cereus biofilm formation. Copyright © 2015 Elsevier B.V. All rights reserved.

Non-conductive ferromagnetic carbon-coated (Co, Ni) metal/polystyrene nanocomposites films

DOE Office of Scientific and Technical Information (OSTI.GOV)

Takacs, H., E-mail: helene.takacs@gmail.com; LTM-CNRS-UJF, CEA, LETI, Minatec Campus, Grenoble 38054; Viala, B.

2016-03-07

This article reports non-conductive ferromagnetic properties of metal/polymer nanocomposite films intended to be used for RF applications. The nanocomposite arrangement is unique showing a core double-shell structure of metal-carbon-polystyrene: M/C//P{sub 1}/P{sub 2}, where M = Co, Ni is the core material, C = graphene or carbon is the first shell acting as a protective layer against oxidation, P{sub 1} = pyrene-terminated polystyrene is the second shell for electrical insulation, and P{sub 2} = polystyrene is a supporting matrix (// indicates actual grafting). The nanocomposite formulation is briefly described, and the film deposition by spin-coating is detailed. Original spin-curves are reported and analyzed. One key outcome is the achievementmore » of uniform and cohesive films at the wafer scale. Structural properties of films are thoroughly detailed, and weight and volume fractions of M/C are considered. Then, a comprehensive overview of DC magnetic and electrical properties is reported. A discussion follows on the magnetic softness of the nanocomposites vs. that of a single particle (theoretical) and the raw powder (experimental). Finally, unprecedented achievement of high magnetization (∼0.6 T) and ultra-high resistivity (∼10{sup 10 }μΩ cm) is shown. High magnetization comes from the preservation of the existing protective shell C, with no significant degradation on the particle net-moment, and high electrical insulation is ensured by adequate grafting of the secondary shell P{sub 1}. To conclude, the metal/polymer nanocomposites are situated in the landscape of soft ferromagnetic materials for RF applications (i.e., inductors and antennas), by means of two phase-diagrams, where they play a crucial role.« less

Single-Beam Acoustic Trapping of Red Blood Cells and Polystyrene Microspheres in Flowing Red Blood Cell Saline and Plasma Suspensions.

PubMed

Liu, Hsiao-Chuan; Li, Ying; Chen, Ruimin; Jung, Hayong; Shung, K Kirk

2017-04-01

Single-beam acoustic tweezers (SBATs) represent a new technology for particle and cell trapping. The advantages of SBATs are their deep penetration into tissues, reduction of tissue damage and ease of application to in vivo studies. The use of these tools for applications in drug delivery in vivo must meet the following conditions: large penetration depth, strong trapping force and tissue safety. A reasonable penetration depth for SBATs in the development of in vivo applications was established in a previous study conducted in water with zero velocity. However, capturing objects in flowing fluid can provide more meaningful results. In this study, we investigated the capability of SBATs to trap red blood cells (RBCs) and polystyrene microspheres in flowing RBC suspensions. Two different types of RBC suspension were prepared in this work: an RBC phosphate-buffered saline (PBS) suspension and an RBC plasma suspension. The results indicated that SBATs successfully trapped RBCs and polystyrene microspheres in a flowing RBC PBS suspension with an average steady velocity of 1.6 cm/s in a 2-mm-diameter polyimide. Furthermore, SBATs were found able to trap RBCs in a flowing RBC PBS suspension at speeds as high as 7.9 cm/s in a polyimide tube, which is higher than the velocity in capillaries (0.03 cm/s) and approaches the velocity in arterioles and venules. Moreover, the results also indicated that polystyrene microspheres can be trapped in an RBC plasma suspension, where aggregation is observed. This work represents a step forward in using this tool in actual in vivo experimentation. Copyright © 2016 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Assessment of total arsenic and arsenic species stability in alga samples and their aqueous extracts.

PubMed

García Salgado, S; Quijano Nieto, M A; Bonilla Simón, M M

2008-05-30

In order to achieve reliable information on speciation analysis, it is necessary to assess previously the species stability in the sample to analyse. Furthermore, in those cases where the sample treatment for species extraction is time-consuming, an assessment of the species integrity in the extracts is of paramount importance. Thus, the present paper reports total arsenic and arsenic species stability in alga samples (Sargassum fulvellum and Hizikia fusiformis), as well as in their aqueous extracts, which were stored in amber glass and polystyrene containers at different temperatures. Total arsenic determination was carried out by inductively coupled plasma atomic emission spectroscopy (ICP-AES), after sample acid digestion in a microwave oven, while arsenic speciation was conducted by anion exchange high performance liquid chromatography on-line coupled to ICP-AES, with and without sample introduction by hydride generation (HPLC-ICP-AES and HPLC-HG-ICP-AES), after aqueous microwave-assisted extraction. The results obtained for solid alga samples showed that total arsenic (for Hijiki alga) and arsenic species present (As(V) for Hijiki and NIES No. 9 Sargasso) are stable for at least 12 months when samples are stored in polystyrene containers at +20 degrees C. On the other hand, a different behaviour was observed in the stability of total arsenic and As(V) species in aqueous extracts for both samples, being the best storage conditions for Sargasso extracts a temperature of -18 degrees C and polystyrene containers, under which they are stable for at least 15 days, while Hijiki extracts must be stored in polystyrene containers at +4 degrees C in order to ensure the stability for 10 days.

Time course of haemodynamic, respiratory and inflammatory disturbances induced by experimental acute pulmonary polystyrene microembolism.

PubMed

Dolci, Daniel T; Fuentes, Carolina B; Rolim, Denise; Park, Marcelo; Schettino, Guilherme P P; Azevedo, Luciano C P

2010-01-01

The time course of cardiopulmonary alterations after pulmonary embolism has not been clearly demonstrated and nor has the role of systemic inflammation on the pathogenesis of the disease. This study aimed to evaluate over 12 h the effects of pulmonary embolism caused by polystyrene microspheres on the haemodynamics, lung mechanics and gas exchange and on interleukin-6 production. Ten large white pigs (weight 35-42 kg) had arterial and pulmonary catheters inserted and pulmonary embolism was induced in five pigs by injection of polystyrene microspheres (diameter approximately 300 micromol l(-1)) until a value of pulmonary mean arterial pressure of twice the baseline was obtained. Five other animals received only saline. Haemodynamic and respiratory data and pressure-volume curves of the respiratory system were collected. A bronchoscopy was performed before and 12 h after embolism, when the animals were euthanized. The embolism group developed hypoxaemia that was not corrected with high oxygen fractions, as well as higher values of dead space, airway resistance and lower respiratory compliance levels. Acute haemodynamic alterations included pulmonary arterial hypertension with preserved systemic arterial pressure and cardiac index. These derangements persisted until the end of the experiments. The plasma interleukin-6 concentrations were similar in both groups; however, an increase in core temperature and a nonsignificant higher concentration of bronchoalveolar lavage proteins were found in the embolism group. Acute pulmonary embolism induced by polystyrene microspheres in pigs produces a 12-h lasting hypoxaemia and a high dead space associated with high airway resistance and low compliance. There were no plasma systemic markers of inflammation, but a higher central temperature and a trend towards higher bronchoalveolar lavage proteins were found.

Toxicity of pyrolysis gases from some cellular polymers

NASA Technical Reports Server (NTRS)

Hilado, C. J.; Machado, A. M.

1978-01-01

Various samples of cellular polymers were evaluated for toxicity of pyrolysis gases, using the screening test method developed at the University of San Francisco. The cellular polymer samples included polyimide, polymethacrylimide, polybismaleimide, polyurethane, polyisocyanurate, polyethylene, polychloroprene, polyvinyl chloride, polystyrene, polysiloxane, and polyphosphazene. The cellular polymers exhibited varying levels of toxicity under these test conditions. Among the rigid cellular polymers, times to death were shortest with the imide type foams and longest with polyvinyl chloride and polystyrene. Among the flexible cellular polymers, times to death were shortest with polyimide and polyester, and longest with polychloroprene and polysiloxane. Increased char yield was not necessarily associated with reduced toxicity.

Microcraters formed in glass by low density projectiles

NASA Technical Reports Server (NTRS)

Mandeville, J.-C.; Vedder, J. F.

1971-01-01

Microcraters were produced in soda-lime glass by the impact of low density projectiles of polystyrene with masses between 0.7 and 62 picograms and velocities between 2 and 14 kilometers per second. The morphology of the craters depends on the velocity and angle of incidence of the projectiles. The transitions in morphology of the craters formed by polystyrene spheres occur at higher velocities than they do for more dense projectiles. For oblique impact, the craters are elongated and shallow with the spallation threshold occuring at higher velocity. For normal incidence, the total displaced mass of the target material per unit of projectile kinetic energy increases slowly with the energy.

Retention mechanism of hypercrosslinked polystyrene silica hybrid phase in normal phase chromatography.

PubMed

Wu, Di; Nedev, Georgi K; Lucy, Charles A

2014-11-28

Hypercrosslinked polystyrene phases have been described as quasi-normal phase because they lack discrete polar sites. Retention on the HC-Tol column is investigated using the Snyder-Soczewinski model. Solvent strength of different hexane-solvent binary mobile phase compositions can be predicted with solvent strength of pure dichloromethane (DCM, 0.159), tetrahydrofuran (THF, 0.22), and benzene (0.127). The HC-Tol column is shown to be a localizing adsorptive phase. Also, site-competition delocalization on HC-Tol demonstrates that whatever its adsorption groups are, they are able to participate in lateral interactions. Copyright © 2014 Elsevier B.V. All rights reserved.

Directed Self-Assembly of Poly(2-vinylpyridine)-b-polystyrene-b-poly(2-vinylpyridine) Triblock Copolymer with Sub-15 nm Spacing Line Patterns Using a Nanoimprinted Photoresist Template.

PubMed

Sun, Zhiwei; Chen, Zhenbin; Zhang, Wenxu; Choi, Jaewon; Huang, Caili; Jeong, Gajin; Coughlin, E Bryan; Hsu, Yautzong; Yang, XiaoMin; Lee, Kim Y; Kuo, David S; Xiao, Shuaigang; Russell, Thomas P

2015-08-05

Low molecular weight P2VP-b-PS-b-P2VP triblock copolymer (poly(2-vinlypyridine)-block-polystyrene-block-poly(2-vinylpyridine)] is doped with copper chloride and microphase separated into lamellar line patterns with ultrahigh area density. Salt-doped P2VP-b-PS-b-P2VP triblock copolymer is self-assembled on the top of the nanoimprinted photoresist template, and metallic nanowires with long-range ordering are prepared with platinum-salt infiltration and plasma etching. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Fabrication of polystyrene/gold nanotubes and nanostructure-controlled growth of aluminate.

PubMed

Zhu, Haifeng; Ai, Sufen; He, Qiang; Cui, Yue; Li, Junbai

2007-07-01

Direct adsorption of gold nanoparticles in the inner of alumina template and following immersion of polystyrene (PS) dichloromethane solution in the template resulted in the fabrication of composite nanotubes of PS and gold nanoparticles. Several methods have been used to characterize the tubular structure. Nanostructured sodium aluminates were formed when the anodic alumina oxide membrane was dissolved by the sodium hydroxide. A "flower" shape was found after etching the template while the synthesis process was recorded as function of a time. The results demonstrate that the shape and size of the aluminates nanostructure can be controlled by etching time and the pore diameter of the alumina membrane.

Designing Hollow Nano Gold Golf Balls

PubMed Central

2015-01-01

Hollow/porous nanoparticles, including nanocarriers, nanoshells, and mesoporous materials have applications in catalysis, photonics, biosensing, and delivery of theranostic agents. Using a hierarchical template synthesis scheme, we have synthesized a nanocarrier mimicking a golf ball, consisting of (i) solid silica core with a pitted gold surface and (ii) a hollow/porous gold shell without silica. The template consisted of 100 nm polystyrene beads attached to a larger silica core. Selective gold plating of the core followed by removal of the polystyrene beads produced a golf ball-like nanostructure with 100 nm pits. Dissolution of the silica core produced a hollow/porous golf ball-like nanostructure. PMID:24937196

Absolute Equation-of-State Measurement for Polystyrene from 25 - 60 Mbar Using a Spherically Converging Shock Wave

DOE Office of Scientific and Technical Information (OSTI.GOV)

Glenzer, Siegfried

We have developed an experimental platform for the National Ignition Facility (NIF) that uses spherically converging shock waves for absolute equation of state (EOS) measurements along the principal Hugoniot. In this Letter we present radiographic compression measurements for polystyrene that were taken at shock pressures reaching 60 Mbar (6 TPa). This significantly exceeds previously published results obtained on the Nova laser [Cauble et al., Phys. Rev. Lett. 80, 1248 (1998)] at strongly improved precision, allowing to discriminate between different EOS models. We find excellent agreement with Kohn-Sham Density Functional Theory based molecular dynamics simulations.

Loading and release mechanisms of a biocide in polystyrene-block-poly(acrylic acid) block copolymer micelles.

PubMed

Vyhnalkova, Renata; Eisenberg, Adi; van de Ven, Theo G M

2008-07-24

The kinetics of loading of polystyrene197-block-poly(acrylic acid)47 (PS197-b-PAA47) micelles, suspended in water, with thiocyanomethylthiobenzothiazole biocide and its subsequent release were investigated. Loading of the micelles was found to be a two-step process. First, the surface of the PS core of the micelles is saturated with biocide, with a rate determined by the transfer of solid biocide to micelles during transient micelle-biocide contacts. Next, the biocide penetrates as a front into the micelles, lowering the Tg in the process (non-Fickian case II diffusion). The slow rate of release is governed by the height of the energy barrier that a biocide molecule must overcome to pass from PS into water, resulting in a uniform biocide concentration within the micelle, until Tg is increased to the point that diffusion inside the micelles becomes very slow. Maximum loading of biocide into micelles is approximately 30% (w/w) and is achieved in 1 h. From partition experiments, it can be concluded that the biocide has a similar preference for polystyrene as for ethylbenzene over water, implying that the maximum loading is governed by thermodynamics.

Increased adsorption of histidine-tagged proteins onto tissue culture polystyrene.

PubMed

Holmberg, Maria; Hansen, Thomas Steen; Lind, Johan Ulrik; Hjortø, Gertrud Malene

2012-04-01

In this study we compare histidine-tagged and native proteins with regards to adsorption properties. We observe significantly increased adsorption of proteins with an incorporated polyhistidine amino acid motif (HIS-tag) onto tissue culture polystyrene (TCPS) compared to similar proteins without a HIS-tag. The effect is not observed on polystyrene (PS). Adsorption experiments have been performed at physiological pH (7.4) and the effect was only observed for the investigated proteins that have pI values below or around 7.4. Competitive adsorption experiments with imidazole and ethylenediaminetetraacetic acid (EDTA), as well as adsorption performed at different pH and ionic strength indicates that the high adsorption is caused by electrostatic interaction between negatively charged carboxylate groups on the TCPS surface and positively charged histidine residues in the proteins. Pre-adsorption of bovine serum albumin (BSA) does not decrease the adsorption of HIS-tagged proteins onto TCPS. Our findings identify a potential problem in using HIS-tagged signalling molecule in assays with cells cultured on TCPS, since the concentration of the molecule in solution might be affected and this could critically influence the assay outcome. Copyright © 2011 Elsevier B.V. All rights reserved.

Highly Efficient Antibacterial Surfaces Based on Bacterial/Cell Size Selective Microporous Supports.

PubMed

Vargas-Alfredo, Nelson; Santos-Coquillat, Ana; Martínez-Campos, Enrique; Dorronsoro, Ane; Cortajarena, Aitziber L; Del Campo, Adolfo; Rodríguez-Hernández, Juan

2017-12-27

We report on the fabrication of efficient antibacterial substrates selective for bacteria, i.e., noncytotoxic against mammalian cells. The strategy proposed is based on the different size of bacteria (1-4 μm) in comparison with mammalian cells (above 20 μm) that permit the bacteria to enter in contact with the inner part of micrometer-sized pores where the antimicrobial functionality are placed. On the contrary, mammalian cells, larger in terms of size, remain at the top surface, thus reducing adverse cytotoxic effects and improving the biocompatibility of the substrates. For this purpose, we fabricated well-ordered functional microporous substrates (3-5 μm) using the breath figures approach that enabled the selective functionalization of the pore cavity, whereas the rest of the surface remained unaffected. Microporous surfaces were prepared from polymer blends comprising a homopolymer (i.e., polystyrene) and a block copolymer (either polystyrene-b-poly(dimethylaminoethyl methacrylate) (PDMAEMA) or a quaternized polystyrene-b-poly(dimethylaminoethyl methacrylate)). As a result, porous surfaces with a narrow size distribution and a clear enrichment of the PDMAEMA or the quaternized PDMAEMA block inside the pores were obtained that, in the case of the quaternized PDMAEMA, provided an excellent antimicrobial activity to the films.

Nanopatterned polystyrene-b-poly(acrylic acid) surfaces to modulate cell-material interaction.

PubMed

Lizundia, Erlantz; Sáenz-Pérez, Míriam; Patrocinio, David; Aurrekoetxea, Iskander; dM Vivanco, Maria; Vilas, José Luis

2017-06-01

In this work we explore the effect of surface nanoarchitecture of polystyrene (PS) and polystyrene-b-poly(acrylic acid) (PS-b-PAA) diblock copolymer films on cell viability. PS and PS-b-PAA have been nanopatterned at temperatures of 110, 120 and 140°C using nanoporous aluminium oxide membranes (AAO) as a template. Surface architecture strongly depends on the infiltration temperature and the nature of the infiltrated polymer. High patterning temperatures yield hollow fibre shape architecture at the nanoscale level, which substantially modifies the surface hydrophobicity of the resulting materials. Up to date very scarce reports could be found in the literature dealing with the interaction of microstructured/nanostructured polymeric surfaces with cancer cells. Therefore, MCF-7 breast cancer cells have been selected as a model to conduct cell viability assays. The findings reveal that the fine-tuning of the surface nanoarchitecture contributes to the modification of its biocompatibility. Overall, this study highlights the potential of AAO membranes to obtain well-defined tailored morphologies at nanoscale level and its importance to develop novel soft functional surfaces to be used in the biomedical field. Copyright © 2017 Elsevier B.V. All rights reserved.

Tuning the dynamic range and sensitivity of optical oxygen-sensors by employing differently substituted polystyrene-derivatives

PubMed Central

Koren, Klaus; Hutter, Lukas; Enko, Barbara; Pein, Andreas; Borisov, Sergey M.; Klimant, Ingo

2013-01-01

Ten different polystyrene-derivatives were tested with respect to their potential use as matrix materials for optical oxygen sensors in combination with the platinum(II) meso-tetra(4-fluorophenyl)tetrabenzoporphyrin as indicator dye. Either halogen atoms or bulky residues were introduced as substituents on the phenyl ring. A fine-tuning of the sensor sensitivity was achieved, without compromising solubility of the indicator in the matrix by providing a chemical environment very similar to polystyrene (PS), a standard matrix in optical oxygen sensors. To put the results into perspective, the studied materials were compared to PS regarding sensitivity of the sensor, molecular weight and glass-transition temperature. The materials promise to be viable alternatives to PS with respect to the requirements posed in various sensor application fields. Some of the polymers (e.g. poly(2,6-dichlorostyrene)) promise to be of use in applications requiring measurements from 0 to 100% oxygen due to linearity across this range. Poly(4-tert-butylstyrene) and poly(2,6-fluorostyrene), on the other hand, yield sensors with increased sensitivity. Sensor stability was evaluated as a function of the matrix, a topic which has not received a lot of interest so far. PMID:23576846

Kinetics of Phase Transition from Lamellar to Hexagonally Packed Cylinders for a Triblock Copolymer in a Selective Solvent

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu,Y.; Li, M.; Bansil, R.

2007-01-01

We examined the kinetics of the transformation from the lamellar (LAM) to the hexagonally packed cylinder (HEX) phase for the triblock copolymer, polystyrene-b-poly (ethylene-co-butylene)-b-polystyrene (SEBS) in dibutyl phthalate (DBP), a selective solvent for polystyrene (PS), using time-resolved small-angle X-ray scattering (SAXS). We observe the HEX phase with the EB block in the cores at a lower temperature than that observed for the LAM phase due to the solvent selectivity of DBP for the PS block. Analysis of the SAXS data for a deep temperature quench well below the LAM-HEX transition shows that the transformation occurs in a one-step process. Wemore » calculate the scattering using a geometric model of rippled layers with adjacent layers totally out of phase during the transformation. The agreement of the calculations with the data further supports the continuous transformation mechanism from the LAM to HEX for a deep quench. In contrast, for a shallow quench close to the order-order transition, we find agreement with a two-step nucleation and growth mechanism.« less

Adhesion of Asaia bogorensis to Glass and Polystyrene in the Presence of Cranberry Juice.

PubMed

Antolak, Hubert; Kregiel, Dorota; Czyzowska, Agata

2015-06-01

The aim of the study was to evaluate the adhesion abilities of the acetic acid bacterium Asaia bogorensis to glass and polystyrene in the presence of American cranberry (Vaccinium macrocarpon) juice. The strain of A. bogorensis used was isolated from spoiled commercial fruit-flavored drinking water. The cranberry juice was analyzed for polyphenols, organic acids, and carbohydrates using high-performance liquid chromatography and liquid chromatography-mass spectrometry techniques. The adhesive abilities of bacterial cells in culture medium supplemented with cranberry juice were determined using luminometry and microscopy. The viability of adhered and planktonic bacterial cells was determined by the plate count method, and the relative adhesion coefficient was calculated. This strain of A. bogorensis was characterized by strong adhesion properties that were dependent upon the type of surface. The highest level of cell adhesion was found on the polystyrene. However, in the presence of 10% cranberry juice, attachment of bacterial cells was three times lower. Chemical analysis of juice revealed the presence of sugars, organic acids, and anthocyanins, which were identified as galactosides, glucosides, and arabinosides of cyanidin and peonidin. A-type proanthocyanidins responsible for the antiadhesion properties of V. macrocarpon also were detected.

Preparation of carbon paste electrodes including poly(styrene) attached glycine-Pt(IV) for amperometric detection of glucose.

PubMed

Dönmez, Soner; Arslan, Fatma; Sarı, Nurşen; Kurnaz Yetim, Nurdan; Arslan, Halit

2014-04-15

In this study, a novel carbon paste electrode that is sensitive to glucose was prepared using the nanoparticles modified (4-Formyl-3-methoxyphenoxymethyl) with polystyren (FMPS) with L-Glycine-Pt(IV) complexes. Polymeric nanoparticles having Pt(IV) ion were prepared from (4-Formyl-3-methoxyphenoxymethyl) polystyren, glycine and PtCl4 by template method. Glucose oxidase enzyme was immobilized to a modified carbon paste electrode (MCPE) by cross-linking with glutaraldehyde. Determination of glucose was carried out by oxidation of enzymatically produced H2O2 at 0.5 V vs. Ag/AgCl. Effects of pH and temperature were investigated, and optimum parameters were found to be 8.0 and 55°C, respectively. Linear working range of the electrode was 5.0×10(-6)-1.0×10(-3) M, R(2)=0.997. Storage stability and operational stability of the enzyme electrode were also studied. Glucose biosensor gave perfect reproducible results after 10 measurements with 2.3% relative standard deviation. Also, it had good storage stability (gave 53.57% of the initial amperometric response at the end of 33th day). © 2013 Published by Elsevier B.V.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Wenwen; Wang, Weiyu; Li, Hui

In this study, high molecular weight “comb-shaped” graft copolymers, poly(isoprene-g-styrene), with polyisoprene as the backbone and polystyrene as side chains, were synthesized via free radical emulsion polymerization by copolymerization of isoprene with a polystyrene macromonomer synthesized using anionic polymerization. A small amount of toluene was used in order to successfully disperse the macromonomer. Both a redox and thermal initiation system were used in the emulsion polymerization, and the latex particle size and distribution were investigated by dynamic light scattering. The structural characteristics of the macromonomer and comb graft copolymers were investigated through use of size exclusion chromatography, spectroscopy, microscopy, thermalmore » analysis, and rheology. While the macromonomer was successfully copolymerized to obtain the desired multigraft copolymers, small amounts of unreacted macromonomer remained in the products, reflecting its reduced reactivity due to steric effects. Nevertheless, the multigraft copolymers obtained were very high in molecular weight (5–12 × 10 5 g/mol) and up to 10 branches per chain, on average, could be incorporated. A material incorporating 29 wt% polystyrene exhibits a disordered microphase separated morphology and elastomeric properties. As a result, these materials show promise as new, highly tunable, and potentially low cost thermoplastic elastomers.« less

Removal of arsenic, vanadium, and/or nickel compounds from petroliferous liquids

DOEpatents

Fish, Richard H.

1986-01-01

Described is a process for removing arsenic, vanadium, and/or nickel from petroliferous derived liquids by contacting said liquid at an elevated temperature with a divinylbenzene-crosslinked polystyrene having catechol ligands anchored thereon. For vanadium and nickel removal an amine, preferably a diamine is included. Also, described is a process for regenerating spent catecholated polystyrene by removal of the arsenic, vanadium, and/or nickel bound to it from contacting petroliferous liquid as described above and involves: treating the spent polymer containing any vanadium and/or nickel with an aqueous acid to achieve an acid pH; and, separating the solids from the liquid; and then treating said spent catecholated polystyrene, at a temperature in the range of about 20.degree. to 100.degree. C. with an aqueous solution of at least one carbonate and/or bicarbonate of ammonium, alkali and alkaline earth metals, said solution having a pH between about 8 and 10; and, separating the solids and liquids from each other. Preferably the regeneration treatment of arsenic containing catecholated polymer is in two steps wherein the first step is carried out with an aqueous alcoholic carbonate solution containing lower alkyl alcohol, and, the steps are repeated using a bicarbonate.

Removal of arsenic, vanadium and/or nickel compounds from spent catecholated polymer

DOEpatents

Fish, R.H.

1987-04-21

Described is a process for removing arsenic, vanadium, and/or nickel from petroliferous derived liquids by contacting said liquid at an elevated temperature with a divinylbenzene-crosslinked polystyrene having catechol ligands anchored thereon. For vanadium and nickel removal an amine, preferably a diamine is included. Also, described is a process for regenerating spent catecholated polystyrene by removal of the arsenic, vanadium, and/or nickel bound to it from contacting petroliferous liquid as described above and involves: treating the spent polymer containing any vanadium and/or nickel with an aqueous acid to achieve an acid pH; and, separating the solids from the liquid; and then treating said spent catecholated polystyrene, at a temperature in the range of about 20 to 100 C with an aqueous solution of at least one carbonate and/or bicarbonate of ammonium, alkali and alkaline earth metals, said solution having a pH between about 8 and 10; and, separating the solids and liquids from each other. Preferably the regeneration treatment of arsenic containing catecholated polymer is in two steps wherein the first step is carried out with an aqueous alcoholic carbonate solution containing lower alkyl alcohol, and, the steps are repeated using a bicarbonate.

Removal of arsenic, vanadium and/or nickel compounds from spent catecholated polymer

DOEpatents

Fish, Richard H.

1987-01-01

Described is a process for removing arsenic, vanadium, and/or nickel from petroliferous derived liquids by contacting said liquid at an elevated temperature with a divinylbenzene-crosslinked polystyrene having catechol ligands anchored thereon. For vanadium and nickel removal an amine, preferably a diamine is included. Also, described is a process for regenerating spent catecholated polystyrene by removal of the arsenic, vanadium, and/or nickel bound to it from contacting petroliferous liquid as described above and involves: treating the spent polymer containing any vanadium and/or nickel with an aqueous acid to achieve an acid pH; and, separating the solids from the liquid; and then treating said spent catecholated polystyrene, at a temperature in the range of about 20.degree. to 100.degree. C. with an aqueous solution of at least one carbonate and/or bicarbonate of ammonium, alkali and alkaline earth metals, said solution having a pH between about 8 and 10; and, separating the solids and liquids from each other. Preferably the regeneration treatment of arsenic containing catecholated polymer is in two steps wherein the first step is carried out with an aqueous alcoholic carbonate solution containing lower alkyl alcohol, and, the steps are repeated using a bicarbonate.

Can vector control play a useful supplementary role against bancroftian filariasis?

PubMed Central

Maxwell, C. A.; Mohammed, K.; Kisumku, U.; Curtis, C. F.

1999-01-01

A single campaign of mass treatment for bancroftian filariasis with diethylcarbamazine (DEC) in Makunduchi, a town in Zanzibar, United Republic of Tanzania, combined with elimination of mosquito breeding in pit latrines with polystyrene beads was followed by a progressive decline over a 5-year period in the microfilarial rate from 49% to 3%. Evidence that vector control had contributed to this long-term decline was obtained by comparison with another town, Moga, where a DEC campaign was used without vector control and where resurgence of microfilariae could be observed 3-6 years after the campaign. In Zanzibar town, treatment of 3844 wet pit latrines and cesspits with polystyrene beads reduced the adult mosquito population in houses by about 65%. Supplementary treatment of open drains and marshes with Bacillus sphaericus produced little or no additional reduction compared to a sector of the town where only pit treatment with polystyrene was carried out. The cost and effort of achieving the 65% reduction in mosquito population could hardly be justified for its impact on filariasis alone, but its noticeable impact on biting nuisance might help to gain community support for an integrated programme. PMID:10083712

Dose response evaluation of a low-density normoxic polymer gel dosimeter using MRI

NASA Astrophysics Data System (ADS)

Haraldsson, P.; Karlsson, A.; Wieslander, E.; Gustavsson, H.; Bäck, S. Å. J.

2006-02-01

A low-density (~0.6 g cm-3) normoxic polymer gel, containing the antioxidant tetrakis (hydroxymethyl) phosponium (THP), has been investigated with respect to basic absorbed dose response characteristics. The low density was obtained by mixing the gel with expanded polystyrene spheres. The depth dose data for 6 and 18 MV photons were compared with Monte Carlo calculations. A large volume phantom was irradiated in order to study the 3D dose distribution from a 6 MV field. Evaluation of the gel was carried out using magnetic resonance imaging. An approximately linear response was obtained for 1/T2 versus dose in the dose range of 2 to 8 Gy. A small decrease in the dose response was observed for increasing concentrations of THP. A good agreement between measured and Monte Carlo calculated data was obained, both for test tubes and the larger 3D phantom. It was shown that a normoxic polymer gel with a reduced density could be obtained by adding expanded polystyrene spheres. In order to get reliable results, it is very important to have a uniform distribution of the gel and expanded polystyrene spheres in the phantom volume.

Structural properties of atactic polystyrene adsorbed onto solid surfaces.

PubMed

Tatek, Yergou B; Tsige, Mesfin

2011-11-07

In the present work, we are studying the local conformation of chains in a thin film of polystyrene adsorbed on a solid substrate by using atomistically detailed simulations. The simulations are carried out by using the readily available and massively parallel molecular dynamics code known as LAMMPS. In particular, a special emphasis is given to the density and orientation of side chains (which consist of phenyl groups and methylene units) at solid/polymer and polymer/vacuum interfaces. Three types of substrates were used in our study: α-quartz, graphite, and amorphous silica. Our investigation was restricted to atactic polystyrene. Our results show that the density and structural properties of side chains depend on the type of surface. An excess of phenyl rings is observed near the α-quartz substrate while the film adsorbed on graphite is depleted in C(6)H(5). Moreover, the orientation of the rings and methylene units on the substrate/film interface show a strong dependence on the type of the substrate, while the rings at the film/vacuum interface show a marked tendency to point outward, away from the film. The results we obtained are in a large part in good agreement with previous experimental and simulation results.

Organometallic Polymeric Conductors

NASA Technical Reports Server (NTRS)

1997-01-01

For aerospace applications, the use of polymers can result in tremendous weight savings over metals. Suitable polymeric materials for some applications like EMI shielding, spacecraft grounding, and charge dissipation must combine high electrical conductivity with long-term environmental stability, good processability, and good mechanical properties. Recently, other investigators have reported hybrid films made from an electrically conductive polymer combined with insulating polymers. In all of these instances, the films were prepared by infiltrating an insulating polymer with a precursor for a conductive polymer (either polypyrrole or polythiophene), and oxidatively polymerizing the precursor in situ. The resulting composite films have good electrical conductivity, while overcoming the brittleness inherent in most conductive polymers. The highest conductivities reported (approximately 4/Scm) were achieved with polythiophene in a polystyrene host polymer. The best films using a polyamide as base polymer were four orders of magnitude less conductive than the polystyrene films. The authors suggested that this was because polyimides were unable to swell sufficiently for infiltration of monomer as in the polystyrene. It was not clear, however, if the different conductivities obtained were merely the result of differing oxidation conditions. Oxidation time, temperature and oxidant concentration varied widely among the studies.

Microbial degradation of [C14C]polystyrene and 1,3-diphenylbutane.

PubMed

Sielicki, M; Focht, D D; Martin, J P

1978-07-01

Microbial degradation of [beta-14C]polystyrene and 1,3-diphenylbutane, a compound structurally representing the smallest repeating unit of styrene (dimer), was investigated in soil and liquid enrichment cultures. Degradation rates in soil, as determined by 14CO2 evolution from applied [14C]polystyrene, varied from 1.5 to 3.0% for a 4-month period. Although relatively low, these percentages were 15 to 30 times greater than values previously reported. Enrichment cultures, containing 1,3-diphenylbutane as the only carbon souce, were used to determine the mechanisms of microbial oxidation of the polymer chain ends. Metabolism of 1,3-diphenylbutane appeared to involve the attack by a monooxygenease to form 2-phenyl-4-hydroxyphenylbutane followed by a further oxidation and subsequent fission of the benzene ring to yield 4-phenylvaleric acid and an unidentified 5-carbon fragment via the classic meta-fission pathway. Phenylacetic acid was probably formed from 4-phenylvaleric acid by subsequent beta-oxidation of the side chain, methyl-oxidation and decarboxylation. An initial examination of the population of microorganisms in the diphenylbutane enrichment cultures indicated that these oxidative reactions are carried out by common soil microorganism of the genera Bacillus, Pseudomonas, Micrococcus, and Nocardia.

Adhesive protein interactions with chitosan: consequences for valve endothelial cell growth on tissue-engineering materials.

PubMed

Cuy, Janet L; Beckstead, Benjamin L; Brown, Chad D; Hoffman, Allan S; Giachelli, Cecilia M

2003-11-01

Stable endothelialization of a tissue-engineered heart valve is essential for proper valve function, although adhesive characteristics of the native valve endothelial cell (VEC) have rarely been explored. This research evaluated VEC adhesive qualities and attempted to enhance VEC growth on the biopolymer chitosan, a novel tissue-engineering scaffold material with promising biological and chemical properties. Aortic VEC cultures were isolated and found to preferentially adhere to fibronectin, collagen types IV and I over laminin and osteopontin in a dose-dependent manner. Seeding of VEC onto comparison substrates revealed VEC growth and morphology to be preferential in the order: tissue culture polystyrene > gelatin, poly(DL-lactide-co-glycolide), chitosan > poly(hydroxy alkanoate). Adhesive protein precoating of chitosan did not significantly enhance VEC growth, despite equivalent protein adsorption as to polystyrene. Initial cell adhesion to protein-precoated chitosan, however, was higher than for polystyrene. Composite chitosan/collagen type IV films were investigated as an alternative to simple protein precoatings, and were shown to improve VEC growth and morphology over chitosan alone. These findings suggest potential manipulation of chitosan properties to improve amenability to valve tissue-engineering applications. Copyright 2003 Wiley Periodicals, Inc.

Surface Layer Matrix-Assisted Laser Desorption Ionization Time of Flight Mass Spectrometry (SL-MALDI-ToF-MS) Analysis of Polymer Blend Surface Composition

NASA Astrophysics Data System (ADS)

Hill, Jacob A.

The composition of a polymer blend is generally different at the surface than in the bulk and the gradient in composition with depth has important implications for surface properties. The determination of the surface composition presents various challenges which continue to prompt the development of new techniques for quantifying the composition. Here the technique of surface layer matrix-assisted laser desorption ionization time-of-flight mass spectrometry (SL-MALDI-ToF-MS) has been further developed to address four specific questions of polymer blend surface behavior within the general category of surface composition determination. The first question is how chain length disparity affects surface segregation in the case that the disparity is quite small. While such segregation is known for blends containing low molecular weight additives or systems with large polydispersity, it has not been reported for anionically polymerized polymers that are viewed, in practice, as monodisperse. For 6 kDa polystyrene the number average molecular weight (Mn) at the surface is ca. 300 Da (5%) lower than that in the bulk and for 7 kDa polymethyl methacrylate the shift is ca. 500 Da. The second question is how chain-end functionalization effects not the location of chain ends at the surface, but rather the prevalence at the surface of any part of a chain having an end functionalization. A key issue of such an approach is understanding precisely where the functionalities ultimately reside and how this functionalization shifts the balance of forces that determine the distribution of chains with depth. The surface of a blend of 6 kDa polystyrene and 6 kDa polystyrene functionalized with hydroxymethyl ends is not only depleted of the higher energy end groups, but is depleted of any segments belonging to the functionalized chains. This is demonstrated using SL-MALDI-ToF-MS, which detects entire chains that have any repeat unit at the outer surface, and requires no labelling. This study was extended to the surfaces of blends of 6 kDa polystyrene and 6 kDa polystyrene functionalized with hydroxyethyl ends. Blends of all compositions less than 90 wt. % functionalized chains showed depletion. Finally, the challenge of determining lateral variations in the surface composition has been addressed with the development of SL-MALDI-ToF-MS imaging (SL-MALDI-ToF-MSI). Key to developing imaging capability was improving the lateral uniformity of the matrix deposition. This uniformity was achieved using solvent free sublimation of matrix and salt onto the sample's surface. The capabilities of SL-MALDI-ToF-MSI were demonstrated by imaging the absence of material due to masking during material deposition, mechanical scribing or solvent perturbation at the surface of low molecular weight poly(methyl methacrylate) and polystyrene thin films. SL-MALDI-ToF MSI was made possible through the first uniform, solvent free simultaneous sublimation of matrix and salt onto the material's surface.

Coaxial atomic force microscope probes for dielectrophoresis of DNA under different buffer conditions

NASA Astrophysics Data System (ADS)

Tao, Yinglei; Kumar Wickramasinghe, H.

2017-02-01

We demonstrate a coaxial AFM nanoprobe device for dielectrophoretic (DEP) trapping of DNA molecules in Tris-EDTA (TE) and phosphate-buffered saline (PBS) buffers. The DEP properties of 20 nm polystyrene beads were studied with coaxial probes in media with different conductivities. Due to the special geometry of our DEP probe device, sufficiently high electric fields were generated at the probe end to focus DNA molecules with positive DEP. DEP trapping for both polystyrene beads and DNA molecules was quantitatively analyzed over the frequency range from 100 kHz to 50 MHz and compared with the Clausius-Mossotti theory. Finally, we discussed the negative effect of medium salinity during DEP trapping.

In situ grazing incidence small-angle X-ray scattering investigation of polystyrene nanoparticle spray deposition onto silicon.

PubMed

Herzog, Gerd; Benecke, Gunthard; Buffet, Adeline; Heidmann, Berit; Perlich, Jan; Risch, Johannes F H; Santoro, Gonzalo; Schwartzkopf, Matthias; Yu, Shun; Wurth, Wilfried; Roth, Stephan V

2013-09-10

We investigated the spray deposition and subsequent self-assembly during drying of a polystyrene nanoparticle dispersion with in situ grazing incidence small-angle X-ray scattering at high time resolution. During the fast deposition of the dispersion and the subsequent evaporation of the solvent, different transient stages of nanoparticle assembly can be identified. In the first stage, the solvent starts to evaporate without ordering of the nanoparticles. During the second stage, large-scale structures imposed by the breakup of the liquid film are observable. In this stage, the solvent evaporates further and nanoparticle ordering starts. In the late third drying stage, the nanoparticles self-assemble into the final layer structure.

Polyvinyl alcohol coating of polystyrene inertial confinement fusion targets

NASA Technical Reports Server (NTRS)

Annamalai, P.; Lee, M. C.; Crawley, R. L.; Downs, R. L.

1985-01-01

An inertial confinement fusion (ICF) target made of polystyrene is first levitated in an acoustic field. The surface of the target is then etched using an appropriate solution (e.g., cyclohexane) to enhance the wetting characteristics. A specially prepared polyvinyl alcohol solution is atomized using an acoustic atomizer and deposited on the surface of the target. The solution is air dried to form a thin coating (2 microns) on the target (outside diameter of about 350-850 microns). Thicker coatings are obtained by repeated applications of the coating solutions. Preliminary results indicate that uniform coatings may be achievable on the targets with a background surface smoothness in the order of 1000 A.

Flow curve analysis of a Pickering emulsion-polymerized PEDOT:PSS/PS-based electrorheological fluid

NASA Astrophysics Data System (ADS)

Kim, So Hee; Choi, Hyoung Jin; Leong, Yee-Kwong

2017-11-01

The steady shear electrorheological (ER) response of poly(3, 4-ethylenedioxythiophene): poly(styrene sulfonate)/polystyrene (PEDOT:PSS/PS) composite particles, which were initially fabricated from Pickering emulsion polymerization, was tested with a 10 vol% ER fluid dispersed in a silicone oil. The model independent shear rate and yield stress obtained from the raw torque-rotational speed data using a Couette type rotational rheometer under an applied electric field strength were then analyzed by Tikhonov regularization, which is the most suitable technique for solving an ill-posed inverse problem. The shear stress-shear rate data also fitted well with the data extracted from the Bingham fluid model.

Parameters estimation of sandwich beam model with rigid polyurethane foam core

NASA Astrophysics Data System (ADS)

Barbieri, Nilson; Barbieri, Renato; Winikes, Luiz Carlos

2010-02-01

In this work, the physical parameters of sandwich beams made with the association of hot-rolled steel, Polyurethane rigid foam and High Impact Polystyrene, used for the assembly of household refrigerators and food freezers are estimated using measured and numeric frequency response functions (FRFs). The mathematical models are obtained using the finite element method (FEM) and the Timoshenko beam theory. The physical parameters are estimated using the amplitude correlation coefficient and genetic algorithm (GA). The experimental data are obtained using the impact hammer and four accelerometers displaced along the sample (cantilevered beam). The parameters estimated are Young's modulus and the loss factor of the Polyurethane rigid foam and the High Impact Polystyrene.

Preparation and magnetic properties of magnetic photonic crystal by using monodisperse polystyrene covered Fe3O4 nanoparticles onto glass substrate

NASA Astrophysics Data System (ADS)

Azizi, Zahra Sadat; Tehranchi, Mohammad Mehdi; Vakili, Seyed Hamed; Pourmahdian, Saeed

2018-05-01

Engineering approach towards combined photonic band gap properties and magnetic/polymer composite particles, attract considerable attention of researchers due to their unique properties. In this research, two different magnetic particles were prepared by nearly monodisperse polystyrene spheres as bead with two concentrations of Fe3O4 nanoparticles to prepare magnetic photonic crystals (MPCs). The crystal surfaces and particles morphology were investigated employing scanning electron microscopy and transmission electron microscopy. The volume fraction of magnetic material embedded into colloidal spheres and their morphology was found to be a key parameter in the optical and magneto-optical properties of transparent MPC.

Study of structural morphologies of thermoresponsive diblock AB and triblock BAB copolymers (A = poly(N-isopropylacrylamide), B = polystyrene)

NASA Astrophysics Data System (ADS)

Rodríguez-Hidalgo, María del Rosario; Soto-Figueroa, César; Vicente, Luis

2018-03-01

Structural morphologies of diblock AB and triblock BAB copolymers (A = poly(N-isopropylacrylamide), B = polystyrene) in aqueous environment have been investigated by dissipative particle dynamics (DPD). In triblock copolymers insoluble PS blocks contract while soluble pNIPAM blocks stay at the periphery forming looped chains as corona. As the temperature is increased there is a continuous morphological transition and micelles form ellipsoidal structures with segregated polymer zones. The phase transition of looped pNIPAM chains occurs at lower temperature than for linear chains and within broader temperature range. It is discussed how the chain topology of pNIPAM affects the phase transition.

Quantitative characterization of collagen in the fibrotic capsule surrounding implanted polymeric microparticles through second harmonic generation imaging

DOE PAGES

Akilbekova, Dana; Bratlie, Kaitlin M.; Abraham, Thomas

2015-06-30

The collagenous capsule formed around an implant will ultimately determine the nature of its in vivo fate. To provide a better understanding of how surface modifications can alter the collagen orientation and composition in the fibrotic capsule, we used second harmonic generation (SHG) microscopy to evaluate collagen organization and structure generated in mice subcutaneously injected with chemically functionalized polystyrene particles. SHG is sensitive to the orientation of a molecule, making it a powerful tool for measuring the alignment of collagen fibers. Additionally, SHG arises from the second order susceptibility of the interrogated molecule in response to the electric field. Variationmore » in these tensor components distinguishes different molecular sources of SHG, providing collagen type specificity. Here, we demonstrated the ability of SHG to differentiate collagen type I and type III quantitatively and used this method to examine fibrous capsules of implanted polystyrene particles. Data presented in this work shows a wide range of collagen fiber orientations and collagen compositions in response to surface functionalized polystyrene particles. Dimethylamino functionalized particles were able to form a thin collagenous matrix resembling healthy skin. These findings have the potential to improve the fundamental understanding of how material properties influence collagen organization and composition quantitatively.« less

Stretchable, adhesive and ultra-conformable elastomer thin films.

PubMed

Sato, Nobutaka; Murata, Atsushi; Fujie, Toshinori; Takeoka, Shinji

2016-11-16

Thermoplastic elastomers are attractive materials because of the drastic changes in their physical properties above and below the glass transition temperature (T g ). In this paper, we report that free-standing polystyrene (PS, T g : 100 °C) and polystyrene-polybutadiene-polystyrene triblock copolymer (SBS, T g : -70 °C) thin films with a thickness of hundreds of nanometers were prepared by a gravure coating method. Among the mechanical properties of these thin films determined by bulge testing and tensile testing, the SBS thin films exhibited a much lower elastic modulus (ca. 0.045 GPa, 212 nm thickness) in comparison with the PS thin films (ca. 1.19 GPa, 217 nm thickness). The lower elastic modulus and lower thickness of the SBS thin films resulted in higher conformability and thus higher strength of adhesion to an uneven surface such as an artificial skin model with roughness (R a = 10.6 μm), even though they both have similar surface energies. By analyzing the mechanical properties of the SBS thin films, the elastic modulus and thickness of the thin films were strongly correlated with their conformability to a rough surface, which thus led to a high adhesive strength. Therefore, the SBS thin films will be useful as coating layers for a variety of materials.

The tracer diffusion coefficient of soft nanoparticles in a linear polymer matrix

DOE PAGES

Imel, Adam E.; Rostom, Sahar; Holley, Wade; ...

2017-03-09

The diffusion properties of nanoparticles in polymer nanocomposites are largely unknown and are often difficult to determine experimentally. To address this shortcoming, we have developed a novel method to determine the tracer diffusion coefficient of soft polystyrene nanoparticles in a linear polystyrene matrix. Monitoring the interdiffusion of soft nanoparticles into a linear polystyrene matrix provides the mutual diffusion coefficient of this system, from which the tracer diffusion coefficient of the soft nanoparticle can be determined using the slow mode theory. Utilizing this protocol, the role of nanoparticle molecular weight and rigidity on its tracer diffusion coefficient is provided. These resultsmore » demonstrate that the diffusive behavior of these soft nanoparticles differ from that of star polymers, which is surprising since our recent studies suggest that the nanoparticle interacts with a linear polymer similarly to that of a star polymer. It appears that these deformable nanoparticles mostly closely mimic the diffusive behavior of fractal macromolecular architectures or microgels, where the transport of the nanoparticle relies on the cooperative motion of neighboring linear chains. Finally, the less cross-linked, and thus more deformable, nanoparticles diffuse faster than the more highly crosslinked nanoparticles, presumably because the increased deformability allows the nanoparticle to distort and fit into available space.« less

Transfer of Fas (CD95) protein from the cell surface to the surface of polystyrene beads coated with anti-Fas antibody clone CH-11

PubMed Central

Sawai, H.; Domae, N.

2010-01-01

Mouse monoclonal anti-Fas (CD95) antibody clone CH-11 has been widely used in research on apoptosis. CH-11 has the ability to bind to Fas protein on cell surface and induce apoptosis. Here, we used polystyrene beads coated with CH-11 to investigate the role of lipid rafts in Fas-mediated apoptosis in SKW6.4 cells. Unexpectedly, by treatment of the cells with CH-11-coated beads Fas protein was detached from cell surface and transferred to the surface of CH-11-coated beads. Western blot analysis showed that Fas protein containing both extracellular and intracellular domains was attached to the beads. Fas protein was not transferred from the cells to the surface of the beads coated with other anti-Fas antibodies or Fas ligand. Similar phenomenon was observed in Jurkat T cells. Furthermore, CH-11-induced apoptosis was suppressed by pretreatment with CH-11-coated beads in Jurkat cells. These results suggest that CH-11 might possess distinct properties on Fas protein compared with other anti-Fas antibodies or Fas ligand, and also suggest that caution should be needed to use polystyrene beads coated with antibodies such as CH-11. PMID:20353915

Quantitative Characterization of Collagen in the Fibrotic Capsule Surrounding Implanted Polymeric Microparticles through Second Harmonic Generation Imaging.

PubMed

Akilbekova, Dana; Bratlie, Kaitlin M

2015-01-01

The collagenous capsule formed around an implant will ultimately determine the nature of its in vivo fate. To provide a better understanding of how surface modifications can alter the collagen orientation and composition in the fibrotic capsule, we used second harmonic generation (SHG) microscopy to evaluate collagen organization and structure generated in mice subcutaneously injected with chemically functionalized polystyrene particles. SHG is sensitive to the orientation of a molecule, making it a powerful tool for measuring the alignment of collagen fibers. Additionally, SHG arises from the second order susceptibility of the interrogated molecule in response to the electric field. Variation in these tensor components distinguishes different molecular sources of SHG, providing collagen type specificity. Here, we demonstrated the ability of SHG to differentiate collagen type I and type III quantitatively and used this method to examine fibrous capsules of implanted polystyrene particles. Data presented in this work shows a wide range of collagen fiber orientations and collagen compositions in response to surface functionalized polystyrene particles. Dimethylamino functionalized particles were able to form a thin collagenous matrix resembling healthy skin. These findings have the potential to improve the fundamental understanding of how material properties influence collagen organization and composition quantitatively.

Quantitative Characterization of Collagen in the Fibrotic Capsule Surrounding Implanted Polymeric Microparticles through Second Harmonic Generation Imaging

PubMed Central

Akilbekova, Dana; Bratlie, Kaitlin M.

2015-01-01

The collagenous capsule formed around an implant will ultimately determine the nature of its in vivo fate. To provide a better understanding of how surface modifications can alter the collagen orientation and composition in the fibrotic capsule, we used second harmonic generation (SHG) microscopy to evaluate collagen organization and structure generated in mice subcutaneously injected with chemically functionalized polystyrene particles. SHG is sensitive to the orientation of a molecule, making it a powerful tool for measuring the alignment of collagen fibers. Additionally, SHG arises from the second order susceptibility of the interrogated molecule in response to the electric field. Variation in these tensor components distinguishes different molecular sources of SHG, providing collagen type specificity. Here, we demonstrated the ability of SHG to differentiate collagen type I and type III quantitatively and used this method to examine fibrous capsules of implanted polystyrene particles. Data presented in this work shows a wide range of collagen fiber orientations and collagen compositions in response to surface functionalized polystyrene particles. Dimethylamino functionalized particles were able to form a thin collagenous matrix resembling healthy skin. These findings have the potential to improve the fundamental understanding of how material properties influence collagen organization and composition quantitatively. PMID:26125551

Electrospun superhydrophobic polystyrene hollow fiber as a probe for liquid-liquid microextraction with gas chromatography-mass spectrometry.

PubMed

Bagheri, Habib; Baktash, Mohammad Yahya; Jahandar, Kimia

2016-10-01

A superhydrophobic polystyrene hollow fiber was electrospun around a copper spring collector. This approach led to the construction of a hollow fiber membrane, and the copper spring acted as a scaffold. The characteristic properties of the hollow fiber were studied by scanning electron microscopy. The membrane was used as a probe to transfer the extracting solvent from aquatic media to a gas chromatograph. After performing the liquid-liquid microextraction procedure on 10 mL of water sample by octanol, the whole solution was passed through the prepared polystyrene hollow fiber. Propanol, containing 2 mg/L lindane as the internal standard, was used for desorption and an aliquot of 2 μL of the desorbing solvent was subsequently injected into gas chromatography with mass spectrometry. Effects of different parameters influencing the extraction efficiency were optimized. The limits of detection and quantification were 2 and 6 ng/L, respectively. The relative standard deviations at a concentration level of 100 ng/L were between 2 and 6% (n = 3) while the method linearity ranged from 6 to 200 ng/L. Some real water samples were analyzed by the developed method and relative recoveries were in the range of 76-107%. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

3D investigation on polystyrene colloidal crystals by floatage self-assembly with mixed solvent via synchrotron radiation x-ray phase-contrast computed tomography

NASA Astrophysics Data System (ADS)

Fu, Yanan; Xie, Honglan; Deng, Biao; Du, Guohao; Xiao, Tiqiao

2017-06-01

The floatage self-assembly method was introduced with mixed solvent as the medium of polystyrene sphere suspension to fabricate the colloidal crystal. The three dimensional (3D) void system of the colloidal crystal was noninvasively characterized by synchrotron radiation phase-contrast computed tomography, and the quantitative image analysis was implemented aiming to the polystyrene sphere colloidal crystal. Comparing with gravity sedimentation method, the three samples fabricated from floatage self-assembly with mixed solvents have the lowest porosity, and when ethylene glycol and water were mixed with ratio of 1:1, the lowest porosity of 27.49% could be achieved, that has been very close to the minimum porosity of ordered 3D monodisperse sphere array (26%). In single slices, the porosities and fractal dimension for the voids were calculated. The results showed that two factors would significantly influence the porosity of the whole colloidal crystal: the first deposited sphere layer's orderliness and the sedimentation speed of the spheres. The floatage self-assembly could induce a stable close-packing process, resulted from the powerful nucleation force-lateral capillary force coupled with the mixed solvent to regulate the floating upward speed for purpose of matching the assembly rate.

Accurately controlled sequential self-folding structures by polystyrene film

NASA Astrophysics Data System (ADS)

Deng, Dongping; Yang, Yang; Chen, Yong; Lan, Xing; Tice, Jesse

2017-08-01

Four-dimensional (4D) printing overcomes the traditional fabrication limitations by designing heterogeneous materials to enable the printed structures evolve over time (the fourth dimension) under external stimuli. Here, we present a simple 4D printing of self-folding structures that can be sequentially and accurately folded. When heated above their glass transition temperature pre-strained polystyrene films shrink along the XY plane. In our process silver ink traces printed on the film are used to provide heat stimuli by conducting current to trigger the self-folding behavior. The parameters affecting the folding process are studied and discussed. Sequential folding and accurately controlled folding angles are achieved by using printed ink traces and angle lock design. Theoretical analyses are done to guide the design of the folding processes. Programmable structures such as a lock and a three-dimensional antenna are achieved to test the feasibility and potential applications of this method. These self-folding structures change their shapes after fabrication under controlled stimuli (electric current) and have potential applications in the fields of electronics, consumer devices, and robotics. Our design and fabrication method provides an easy way by using silver ink printed on polystyrene films to 4D print self-folding structures for electrically induced sequential folding with angular control.

The effect of polymer architecture on the interdiffusion in thin polymer films

NASA Astrophysics Data System (ADS)

Caglayan, Ayse; Yuan, Guangcui; Satija, Sushil K.; Uhrig, David; Hong, Kunlun; Akgun, Bulent

Branched polymer chains have been traditionally used in industrial applications as additives. Recently they have found applications in electrochromic displays, lithography, biomedical coatings and targeting multidrug resistant bacteria. In some of these applications where they are confined in thin layers, it is important to understand the relation between the mobility and polymer chain architecture to optimize the processing conditions. Earlier interdiffusion measurements on linear and cyclic polymer chains demonstrated the key role of chain architecture on mobility. We have determined the vertical diffusion coefficients of the star polystyrene chains in thin films as a function of number of polymer arms, molecular weight per arm, and film thickness using neutron reflectivity (NR) and compare our results with linear chains of identical total molecular weight. Bilayer samples of 4-arm and 8-arm protonated polystyrenes (hPS) and deuterated polystyrenes (dPS) were used to elucidate the effect of polymer chain architecture on polymer diffusion. NR measurements indicate that the mobility of polymer chains in thin films get faster as the number of polymer arms increases and the arm molecular weight decreases. Both star polymers showed faster interdiffusion compared to their linear analog. Diffusion coefficient of branched PS chains has a weak dependence on the film thickness.

Microparticle sampling by electrowetting-actuated droplet sweeping.

PubMed

Zhao, Yuejun; Cho, Sung Kwon

2006-01-01

This paper describes a new microparticle sampler where particles can be efficiently swept from a solid surface and sampled into a liquid medium using moving droplets actuated by the electrowetting principle. We successfully demonstrate that super hydrophilic (2 microm and 7.9 microm diameter glass beads of about 14 degrees contact angle), intermediate hydrophilic (7.5 microm diameter polystyrene beads of about 70 degrees contact angle), and super hydrophobic (7.9 microm diameter Teflon-coated glass beads and 3 microm size PTFE particles of over 110 degrees contact angles) particles on a solid surface are picked up by electrowetting-actuated moving droplets. For the glass beads as well as the polystyrene beads, the sampling efficiencies are over 93%, in particular over 98% for the 7.9 microm glass beads. For the PTFE particles, however, the sampling efficiency is measured at around 70%, relatively lower than that of the glass and polystyrene beads. This is due mainly to the non-uniformity in particle size and the particle hydrophobicity. In this case, the collected particles staying (adsorbing) on the air-to-water interface hinder the droplet from advancing. This particle sampler requires an extremely small amount of liquid volume (about 500 nanoliters) and will thus be highly compatible and easily integrated with lab-on-a-chip systems for follow-up biological/chemical analyses.

Do plastic particles affect microalgal photosynthesis and growth?

PubMed

Sjollema, Sascha B; Redondo-Hasselerharm, Paula; Leslie, Heather A; Kraak, Michiel H S; Vethaak, A Dick

2016-01-01

The unbridled increase in plastic pollution of the world's oceans raises concerns about potential effects these materials may have on microalgae, which are primary producers at the basis of the food chain and a major global source of oxygen. Our current understanding about the potential modes and mechanisms of toxic action that plastic particles exert on microalgae is extremely limited. How effects might vary with particle size and the physico-chemical properties of the specific plastic material in question are equally unelucidated, but may hold clues to how toxicity, if observed, is exerted. In this study we selected polystyrene particles, both negatively charged and uncharged, and three different sizes (0.05, 0.5 and 6μm) for testing the effects of size and material properties. Microalgae were exposed to different polystyrene particle sizes and surface charges for 72h. Effects on microalgal photosynthesis and growth were determined by pulse amplitude modulation fluorometry and flow cytometry, respectively. None of the treatments tested in these experiments had an effect on microalgal photosynthesis. Microalgal growth was negatively affected (up to 45%) by uncharged polystyrene particles, but only at high concentrations (250mg/L). Additionally, these adverse effects were demonstrated to increase with decreasing particle size. Copyright © 2015 Elsevier B.V. All rights reserved.

Novel Programmable Shape Memory Polystyrene Film: A Thermally Induced Beam-power Splitter.

PubMed

Li, Peng; Han, Yu; Wang, Wenxin; Liu, Yanju; Jin, Peng; Leng, Jinsong

2017-03-09

Micro/nanophotonic structures that are capable of optical wave-front shaping are implemented in optical waveguides and passive optical devices to alter the phase of the light propagating through them. The beam division directions and beam power distribution depend on the design of the micro/nanostructures. The ultimate potential of advanced micro/nanophotonic structures is limited by their structurally rigid, functional singleness and not tunable against external impact. Here, we propose a thermally induced optical beam-power splitter concept based on a shape memory polystyrene film with programmable micropatterns. The smooth film exhibits excellent transparency with a transmittance of 95% in the visible spectrum and optical stability during a continuous heating process up to 90 °C. By patterning double sided shape memory polystyrene film into erasable and switchable micro-groove gratings, the transmission light switches from one designed light divided directions and beam-power distribution to another because of the optical diffraction effect of the shape changing micro gratings during the whole thermal activated recovery process. The experimental and theoretical results demonstrate a proof-of-principle of the beam-power splitter. Our results can be adapted to further extend the applications of micro/nanophotonic devices and implement new features in the nanophotonics.

Novel Programmable Shape Memory Polystyrene Film: A Thermally Induced Beam-power Splitter

PubMed Central

Li, Peng; Han, Yu; Wang, Wenxin; Liu, Yanju; Jin, Peng; Leng, Jinsong

2017-01-01

Micro/nanophotonic structures that are capable of optical wave-front shaping are implemented in optical waveguides and passive optical devices to alter the phase of the light propagating through them. The beam division directions and beam power distribution depend on the design of the micro/nanostructures. The ultimate potential of advanced micro/nanophotonic structures is limited by their structurally rigid, functional singleness and not tunable against external impact. Here, we propose a thermally induced optical beam-power splitter concept based on a shape memory polystyrene film with programmable micropatterns. The smooth film exhibits excellent transparency with a transmittance of 95% in the visible spectrum and optical stability during a continuous heating process up to 90 °C. By patterning double sided shape memory polystyrene film into erasable and switchable micro-groove gratings, the transmission light switches from one designed light divided directions and beam-power distribution to another because of the optical diffraction effect of the shape changing micro gratings during the whole thermal activated recovery process. The experimental and theoretical results demonstrate a proof-of-principle of the beam-power splitter. Our results can be adapted to further extend the applications of micro/nanophotonic devices and implement new features in the nanophotonics. PMID:28276500

Impact of polymer surface characteristics on the microrheological measurement quality of protein solutions - A tracer particle screening.

PubMed

Bauer, Katharina Christin; Schermeyer, Marie-Therese; Seidel, Jonathan; Hubbuch, Jürgen

2016-05-30

Microrheological measurements prove to be suitable to identify rheological parameters of biopharmaceutical solutions. These give information about the flow characteristics but also about the interactions and network structures in protein solutions. For the microrheological measurement tracer particles are required. Due to their specific surface characteristic not all are suitable for reliable measurement results in biopharmaceutical systems. In the present work a screening of melamine, PMMA, polystyrene and surface modified polystyrene as tracer particles were investigated at various protein solution conditions. The surface characteristics of the screened tracer particles were evaluated by zeta potential measurements. Furthermore each tracer particle was used to determine the dynamic viscosity of lysozyme solutions by microrheology and compared to a standard. The results indicate that the selection of the tracer particle had a strong impact on the quality of the microrheological measurement dependent on pH and additive type. Surface modified polystyrene was the only tracer particle that yielded good microrheological results for all tested conditions. The study indicated that the electrostatic surface charge of the tracer particle had a minor impact than its hydrophobicity. This characteristic was the crucial surface property that needs to be considered for the selection of a suitable tracer particle to achieve high measurement accuracy. Copyright © 2016 Elsevier B.V. All rights reserved.

Cationic Polystyrene Resolves Nonalcoholic Steatohepatitis, Obesity, and Metabolic Disorders by Promoting Eubiosis of Gut Microbiota and Decreasing Endotoxemia.

PubMed

Zhu, Airu; Chen, Jingjing; Wu, Pengfei; Luo, Mei; Zeng, Yilan; Liu, Yong; Zheng, Han; Zhang, Li; Chen, Zishou; Sun, Qun; Li, Wenwen; Duan, Yixiang; Su, Danmei; Xiao, Zhixiong; Duan, Zhongping; Zheng, Sujun; Bai, Li; Zhang, Xiaohui; Ju, Zhongyuan; Li, Yan; Hu, Richard; Pandol, Stephen J; Han, Yuan-Ping

2017-08-01

A pandemic of metabolic diseases, consisting of type 2 diabetes, nonalcoholic fatty liver disease, and obesity, has imposed critical challenges for societies worldwide, prompting investigation of underlying mechanisms and exploration of low-cost and effective treatment. In this report, we demonstrate that metabolic disorders in mice generated by feeding with a high-fat diet without dietary vitamin D can be prevented by oral administration of polycationic amine resin. Oral administration of cholestyramine, but not the control uncharged polystyrene, was able to sequester negatively charged bacterial endotoxin in the gut, leading to 1 ) reduced plasma endotoxin levels, 2 ) resolved systemic inflammation and hepatic steatohepatitis, and 3 ) improved insulin sensitivity. Gut dysbiosis, characterized as an increase of the phylum Firmicutes and a decrease of Bacteroidetes and Akkermansia muciniphila, was fully corrected by cholestyramine, indicating that the negatively charged components in the gut are critical for the dysbiosis. Furthermore, fecal bacteria transplant, derived from cholestyramine-treated animals, was sufficient to antagonize the metabolic disorders of the recipient mice. These results indicate that the negatively charged components produced by dysbiosis are critical for biogenesis of metabolic disorders and also show a potential application of cationic polystyrene to treat metabolic disorders through promoting gut eubiosis. © 2017 by the American Diabetes Association.

Synthesis and Characterization of Graft Copolymers Poly(isoprene-g-styrene) of High Molecular Weight by a Combination of Anionic Polymerization and Emulsion Polymerization

DOE PAGES

Wang, Wenwen; Wang, Weiyu; Li, Hui; ...

2015-01-14

In this study, high molecular weight “comb-shaped” graft copolymers, poly(isoprene-g-styrene), with polyisoprene as the backbone and polystyrene as side chains, were synthesized via free radical emulsion polymerization by copolymerization of isoprene with a polystyrene macromonomer synthesized using anionic polymerization. A small amount of toluene was used in order to successfully disperse the macromonomer. Both a redox and thermal initiation system were used in the emulsion polymerization, and the latex particle size and distribution were investigated by dynamic light scattering. The structural characteristics of the macromonomer and comb graft copolymers were investigated through use of size exclusion chromatography, spectroscopy, microscopy, thermalmore » analysis, and rheology. While the macromonomer was successfully copolymerized to obtain the desired multigraft copolymers, small amounts of unreacted macromonomer remained in the products, reflecting its reduced reactivity due to steric effects. Nevertheless, the multigraft copolymers obtained were very high in molecular weight (5–12 × 10 5 g/mol) and up to 10 branches per chain, on average, could be incorporated. A material incorporating 29 wt% polystyrene exhibits a disordered microphase separated morphology and elastomeric properties. As a result, these materials show promise as new, highly tunable, and potentially low cost thermoplastic elastomers.« less

Quaternized poly(styrene ethylene butylene poly styrene)/multiwalled carbon nanotube composites for alkaline fuel cell applications.

PubMed

Vinodh, Rajangam; Sangeetha, Dharmalingam

2013-08-01

The present study is aimed at synthesizing a novel anion exchange composite membrane from quaternized polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene [QPSEBS] and functionalized multi walled carbon nanotubes (f-MWCNT) by solution casting method. The characteristic properties of the QPSEBS/f-MWCNT composite membranes were investigated using Fourier transform infrared (FTIR), UV-Visible spectroscopy, thermo-gravimetric analysis (TGA), scanning electron microscopy (SEM), X-ray diffraction (XRD) studies and Raman spectroscopy. The water uptake, ion exchange capacity, ionic conductivity, methanol permeability and selectivity ratio of the membranes were also studied. The prepared composite membranes were tested in an in-house fabricated alkaline membrane fuel cell (AMFC) set up using Pt/C as the common anode catalyst and three different cathode catalysts namely Pt/C, Pd-Ni/C and Ag/C. Among all the three cathode catalysts, Pt/C for QPSEBS/5% f-MWCNT is found to show the maximum power density and open circuit voltage (OCV) of 187 mW cm(-2) and 0.73 V respectively. For direct methanol alkaline membrane fuel cells (DMAMFC), the OCV of QPSEBS/5% f-MWCNT is found to be 0.76 V and the maximum power density of 59.5 mW cm(-2) is achieved at a current density of 175 mA cm(-2).

Remediation of heavy hydrocarbon impacted soil using biopolymer and polystyrene foam beads.

PubMed

Wilton, Nicholas; Lyon-Marion, Bonnie A; Kamath, Roopa; McVey, Kevin; Pennell, Kurt D; Robbat, Albert

2018-05-05

A green chemistry solution is presented for the remediation of heavy hydrocarbon impacted soils. The two-phase recovery system relies on a plant-based biopolymer, which releases hydrocarbons from soil, and polystyrene foam beads, which recover them from solids and water. The efficiency of the process was demonstrated by comparisons with control experiments, where water, biopolymer, or beads alone yielded total petroleum hydrocarbon (TPH) reductions of 25%, 52%, and 58%, respectively, compared to 94% when 1.25 mL of 1% biopolymer and 15 mg beads per gram of soil were agitated for 30 min. Reductions in TPH content were substantial regardless of soil fraction, with removals of 97%, 91%, and 75% from sand, silt, and clay size fractions, respectively. Additionally, treatment efficiency was independent of carbon number, C 13 to C 43 , as demonstrated by reductions in both diesel fuel (C 13 -C 28 ) and residual-range organics (C 25 -C 43 ) of ∼90%. Compared to other published polymer- and surfactant-based treatment methods, this system requires less mobilizing agent, sorbent, and mixing time. The remediation process is both efficient and sustainable because the biopolymer is re-useable and sourced from renewable crops and polystyrene beads are obtained from recycled materials. Copyright © 2018 Elsevier B.V. All rights reserved.

Removal of arsenic, vanadium, and/or nickel compounds from petroliferous liquids

DOEpatents

Fish, R.H.

1985-05-17

Described is a process for removing arsenic, vanadium, and/or nickel from petroliferous derived liquids (shale oil, SRC, etc.) by contacting said liquid at an elevated temperature with a divinylbenzene-crosslinked polystyrene having catechol ligands anchored thereon. For vanadium and nickel removal an amine, preferably a diamine is included. Also, described is a process for regenerating spent catecholated polystyrene by removal of the arsenic, vanadium, and/or nickel bound to it from contacting petroliferous liquid as described above and involves: treating the spent polymer containing any vanadium and/or nickel with an aqueous acid to achieve an acid pH; and, separating the solids from the liquid; and then treating said spent catecholated polystyrene, at a temperature in the range of about 20/sup 0/ to 100/sup 0/C with an aqueous solution of at least one carbonate and/or bicarbonate of ammonium, alkali and alkaline earth metals, said solution having a pH between about 8 and 10; and, separating the solids and liquids from each other. Preferably the regeneration treatment of arsenic containing catecholated polymer is in two steps wherein the first step is carried out with an aqueous alcoholic carbonate solution containing lower alkyl alcohol, and, the steps are repeated using a bicarbonate.

Self-assembled polystyrene nanospheres for the evaluation of atomic force microscopy tip curvature radius

NASA Astrophysics Data System (ADS)

Colombi, P.; Alessandri, I.; Bergese, P.; Federici, S.; Depero, L. E.

2009-08-01

In this paper, self-assembled polystyrene nanospheres are proposed as a shape characterizer sample for SPM tips. Ordered arrays or 2D islands of polystyrene spheres may be prepared either by sedimentation or by crystallization of the colloidal spheres' suspension. The self-assembling mechanism guarantees high reproducibility; thus the characterizer sample can be 'freshly' prepared at each use, avoiding the problem of time and use deterioration and reducing the problem of sample structure fidelity that occurs when lithographic structures are employed. The spheres could also be deposited on the sample itself in order to speed up the characterization process in applications requiring frequent tip characterizations. We present numerical calculations of geometrical convoluted profiles on the proposed structures showing that, for a variety of different tip shapes, at the border between a couple of touching spheres the tip flanks do not come into contact with the spheres. Due to this behaviour, touching spheres are an optimum characterizer sample for SPM tip curvature radius characterization, enabling a straightforward procedure for calculating the curvature radius from the amplitude of tip oscillation along profiles connecting spheres' centres. The new procedure for the characterization of SPM probes was assessed exploiting different kinds of self-assembled structures and comparing results to those obtained by spiked structures and SEM observations.

Quantitative characterization of collagen in the fibrotic capsule surrounding implanted polymeric microparticles through second harmonic generation imaging

DOE Office of Scientific and Technical Information (OSTI.GOV)

Akilbekova, Dana; Bratlie, Kaitlin M.; Abraham, Thomas

The collagenous capsule formed around an implant will ultimately determine the nature of its in vivo fate. To provide a better understanding of how surface modifications can alter the collagen orientation and composition in the fibrotic capsule, we used second harmonic generation (SHG) microscopy to evaluate collagen organization and structure generated in mice subcutaneously injected with chemically functionalized polystyrene particles. SHG is sensitive to the orientation of a molecule, making it a powerful tool for measuring the alignment of collagen fibers. Additionally, SHG arises from the second order susceptibility of the interrogated molecule in response to the electric field. Variationmore » in these tensor components distinguishes different molecular sources of SHG, providing collagen type specificity. Here, we demonstrated the ability of SHG to differentiate collagen type I and type III quantitatively and used this method to examine fibrous capsules of implanted polystyrene particles. Data presented in this work shows a wide range of collagen fiber orientations and collagen compositions in response to surface functionalized polystyrene particles. Dimethylamino functionalized particles were able to form a thin collagenous matrix resembling healthy skin. These findings have the potential to improve the fundamental understanding of how material properties influence collagen organization and composition quantitatively.« less

Determining Number Concentrations and Diameters of Polystyrene Particles by Measuring the Effective Refractive Index of Colloids Using Surface Plasmon Resonance.

PubMed

Tuoriniemi, Jani; Moreira, Beatriz; Safina, Gulnara

2016-10-04

The capabilities of surface plasmon resonance (SPR) for characterization of colloidal particles were evaluated for 100, 300, and 460 nm nominal diameter polystyrene (PS) latexes. First the accuracy of measuring the effective refractive index (n eff ) of turbid colloids using SPR was quantified. It was concluded that for submicrometer sized PS particles the accuracy is limited by the reproducibility between replicate injections of samples. An SPR method was developed for obtaining the particle mean diameter (d part ) and the particle number concentration (c p ) by fitting the measured n eff of polystyrene (PS) colloids diluted in series with theoretical values calculated using the coherent scattering theory (CST). The d part and c p determined using SPR agreed with reference values obtained from size distributions measured by scanning electron microscopy (SEM), and the mass concentrations stated by the manufacturer. The 100 nm particles adsorbed on the sensing surface, which hampered the analysis. Once the adsorption problem has been overcome, the developed SPR method has potential to become a versatile tool for characterization of colloidal particles. In particular, SPR could form the basis of rapid and accurate methods for measuring the c p of submicrometer particles in dispersion.

Microbial degradation of high impact polystyrene (HIPS), an e-plastic with decabromodiphenyl oxide and antimony trioxide.

PubMed

Sekhar, Vini C; Nampoothiri, K Madhavan; Mohan, Arya J; Nair, Nimisha R; Bhaskar, Thallada; Pandey, Ashok

2016-11-15

Accumulation of electronic waste has increased catastrophically and out of that various plastic resins constitute one of the leading thrown out materials in the electronic machinery. Enrichment medium, containing high impact polystyrene (HIPS) with decabromodiphenyl oxide and antimony trioxide as sole carbon source, was used to isolate microbial cultures. The viability of these cultures in the e-plastic containing mineral medium was further confirmed by triphenyl tetrazolium chloride (TTC) reduction test. Four cultures were identified by 16S rRNA sequencing as Enterobacter sp., Citrobacter sedlakii, Alcaligenes sp. and Brevundimonas diminuta. Biodegradation experiments were carried out in flask level and gelatin supplementation (0.1% w/v) along with HIPS had increased the degradation rate to a maximum of 12.4% (w/w) within 30days. This is the first report for this kind of material. The comparison of FTIR, NMR, and TGA analysis of original and degraded e-plastic films revealed structural changes under microbial treatment. Polystyrene degradation intermediates in the culture supernatant were also detected using HPLC analysis. The gravity of biodegradation was validated by morphological changes under scanning electron microscope. All isolates displayed depolymerase activity to substantiate enzymatic degradation of e-plastic. Copyright © 2016 Elsevier B.V. All rights reserved.

Novel Programmable Shape Memory Polystyrene Film: A Thermally Induced Beam-power Splitter

NASA Astrophysics Data System (ADS)

Li, Peng; Han, Yu; Wang, Wenxin; Liu, Yanju; Jin, Peng; Leng, Jinsong

2017-03-01

Micro/nanophotonic structures that are capable of optical wave-front shaping are implemented in optical waveguides and passive optical devices to alter the phase of the light propagating through them. The beam division directions and beam power distribution depend on the design of the micro/nanostructures. The ultimate potential of advanced micro/nanophotonic structures is limited by their structurally rigid, functional singleness and not tunable against external impact. Here, we propose a thermally induced optical beam-power splitter concept based on a shape memory polystyrene film with programmable micropatterns. The smooth film exhibits excellent transparency with a transmittance of 95% in the visible spectrum and optical stability during a continuous heating process up to 90 °C. By patterning double sided shape memory polystyrene film into erasable and switchable micro-groove gratings, the transmission light switches from one designed light divided directions and beam-power distribution to another because of the optical diffraction effect of the shape changing micro gratings during the whole thermal activated recovery process. The experimental and theoretical results demonstrate a proof-of-principle of the beam-power splitter. Our results can be adapted to further extend the applications of micro/nanophotonic devices and implement new features in the nanophotonics.

Polystyrene-Core, Silica-Shell Scintillant Nanoparticles for Low-Energy Radionuclide Quantification in Aqueous Media.

PubMed

Janczak, Colleen M; Calderon, Isen A C; Mokhtari, Zeinab; Aspinwall, Craig A

2018-02-07

β-particle emitting radionuclides are useful molecular labels due to their abundance in biomolecules. Detection of β-emission from 3 H, 35 S, and 33 P, important biological isotopes, is challenging due to the low energies (E max ≤ 300 keV) and short penetration depths (≤0.6 mm) in aqueous media. The activity of biologically relevant β-emitters is usually measured in liquid scintillation cocktail (LSC), a mixture of energy-absorbing organic solvents, surfactants, and scintillant fluorophores, which places significant limitations on the ability to acquire time-resolved measurements directly in aqueous biological systems. As an alternative to LSC, we developed polystyrene-core, silica-shell nanoparticle scintillators (referred to as nanoSCINT) for quantification of low-energy β-particle emitting radionuclides directly in aqueous solutions. The polystyrene acts as an absorber for energy from emitted β-particles and can be loaded with a range of hydrophobic scintillant fluorophores, leading to photon emission at visible wavelengths. The silica shell serves as a hydrophilic shield for the polystyrene core, enabling dispersion in aqueous media and providing better compatibility with water-soluble analytes. While polymer and inorganic scintillating microparticles are commercially available, their large size and/or high density complicates effective dispersion throughout the sample volume. In this work, nanoSCINT nanoparticles were prepared and characterized. nanoSCINT responds to 3 H, 35 S, and 33 P directly in aqueous solutions, does not exhibit a change in scintillation response between pH 3.0 and 9.5 or with 100 mM NaCl, and can be recovered and reused for activity measurements in bulk aqueous samples, demonstrating the potential for reduced production of LSC waste and reduced total waste volume during radionuclide quantification. The limits of detection for 1 mg/mL nanoSCINT are 130 nCi/mL for 3 H, 8 nCi/mL for 35 S, and <1 nCi/mL for 33 P.

An immunoassay for dibutyl phthalate based on direct hapten linkage to the polystyrene surface of microtiter plates.

PubMed

Wei, Chenxi; Ding, Shumao; You, Huihui; Zhang, Yaran; Wang, Yao; Yang, Xu; Yuan, Junlin

2011-01-01

Dibutyl phthalate (DBP) is predominantly used as a plasticizer inplastics to make them flexible. Extensive use of phthalates in both industrial processes and other consumer products has resulted in the ubiquitous presence of phthalates in the environment. In order to better determine the level of pollution in the environment and evaluate the potential adverse effects of exposure to DBP, immunoassay for DBP was developed. A monoclonal antibody specific to DBP was produced from a stable hybridoma cell line generated by lymphocyte hybridoma technique. An indirect competitive enzyme-linked immunosorbent assay (icELISA) employing direct coating of hapten on polystyrene microtiter plates was established for the detection of DBP. Polystyrene surface was first oxidized by permanganate in dilute sulfuric acid to generate carboxyl groups. Then dibutyl 4-aminophthalate, which is an analogue of DBP, was covalently linked to the carboxyl groups of polystyrene surface with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC). Compared with conjugate coated format (IC(50)=106 ng/mL), the direct hapten coated format (IC(50)=14.6 ng/mL) improved assay sensitivity after careful optimization of assay conditions. The average recovery of DBP from spiked water sample was 104.4% and the average coefficient of variation was 9.95%. Good agreement of the results obtained by the hapten coated icELISA and gas chromatography-mass spectrometry further confirmed the reliability and accuracy of the icELISA for the detection of DBP in certain plastic and cosmetic samples. The stable and efficient hybridoma cell line obtained is an unlimited source of sensitive and specific antibody to DBP. The hapten coated format is proposed as generally applicable because the carboxyl groups on modified microtiter plate surface enables stable immobilization of aminated or hydroxylated hapten with EDC. The developed hapten coated icELISA can be used as a convenient quantitative tool for the sensitive and accurate monitoring DBP in water, plastic and cosmetic samples. © 2011 Wei et al.

Antifouling Properties of a Self-Assembling Glutamic Acid-Lysine Zwitterionic Polymer Surface Coating.

PubMed

Ziemba, Christopher; Khavkin, Maria; Priftis, Dimitris; Acar, Handan; Mao, Jun; Benami, Maya; Gottlieb, Moshe; Tirrell, Matthew; Kaufman, Yair; Herzberg, Moshe

2018-04-23

There is a need for the development of antifouling materials to resist adsorption of biomacromolecules. Here we describe the preparation of a novel zwitterionic block copolymer with the potential to prevent or delay the formation of microbial biofilms. The block copolymer comprised a zwitterionic (hydrophilic) section of alternating glutamic acid (negatively charged) and lysine (positively charged) units and a hydrophobic polystyrene section. Cryo-TEM and dynamic-light-scattering (DLS) results showed that, on average, the block copolymer self-assembled into 7-nm-diameter micelles in aqueous solutions (0 to 100 mM NaCl, pH 6). Quartz crystal microbalance with dissipation monitoring (QCM-D), atomic force microscopy (AFM), and contact angle measurements demonstrated that the block copolymer self-assembled into a brush-like monolayer on polystyrene surfaces. The brush-like monolayer produced from a 100 mg/L block copolymer solution exhibited an average distance, d, of approximately 4-8 nm between each block copolymer molecule (center to center). Once the brush-like monolayer self-assembled, it reduced EPS adsorption onto the polystyrene surface by ∼70% (mass), reduced the rate of bacterial attachment by >80%, and inhibited the development of thick biofilms. QCM-D results revealed that the EPS molecules penetrate between the chains of the brush and adsorb onto the polystyrene surface. Additionally, AFM analyses showed that the brush-like monolayer prevents the adhesion of large (> d) hydrophilic colloids onto the surface via hydration repulsion; however, molecules or colloids small enough to fit between the brush polymers (< d) were able to be adsorbed onto the surface via van der Waals interactions. Overall, we found that the penetration of extracellular organelles, as well as biopolymers through the brush, is critical for the failure of the antifouling coating, and likely could be prevented through tuning of the brush density. Stability and biofilm development testing on multiple surfaces (polypropylene, glass, and stainless steel) support practical applications of this novel block copolymer.

Polystyrene bound oxidovanadium(IV) and dioxidovanadium(V) complexes of histamine derived ligand for the oxidation of methyl phenyl sulfide, diphenyl sulfide and benzoin.

PubMed

Maurya, Mannar R; Arya, Aarti; Kumar, Amit; Pessoa, João Costa

2009-03-28

Ligand Hsal-his (I) derived from salicylaldehyde and histamine has been covalently bound to chloromethylated polystyrene cross-linked with 5% divinylbenzene. Upon treatment with [VO(acac)(2)] in DMF, the polystyrene-bound ligand (abbreviated as PS-Hsal-his, II) gave the stable polystyrene-bound oxidovanadium(iv) complex PS-[V(IV)O(sal-his)(acac)] , which upon oxidation yielded the dioxidovanadium(v) PS-[V(V)O(2)(sal-his)] complex. The corresponding non polymer-bound complexes [V(IV)O(sal-his)(acac)] and [V(V)O(2)(sal-his)] have also been obtained. These complexes have been characterised by IR, electronic, (51)V NMR and EPR spectral studies, and thermal as well as scanning electron micrograph studies. Complexes and have been used as a catalyst for the oxidation of methyl phenyl sulfide, diphenyl sulfide and benzoin with 30% H(2)O(2) as oxidant. Under the optimised reaction conditions, a maximum of 93.8% conversion of methyl phenyl sulfide with 63.7% selectivity towards methyl phenyl sulfoxide and 36.3% towards methyl phenyl sulfone has been achieved in 2 h with 2 . Under similar conditions, diphenyl sulfide gave 83.4% conversion where selectivity of reaction products varied in the order: diphenyl sulfoxide (71.8%) > diphenyl sulfone (28.2%). A maximum of 91.2% conversion of benzoin has been achieved within 6 h, and the selectivities of reaction products are: methylbenzoate (37.0%) > benzil (30.5%) > benzaldehyde-dimethylacetal (22.5%) > benzoic acid (8.1%). The PS-bound complex, 1 exhibits very comparable catalytic potential. These polymer-anchored heterogeneous catalysts do not leach during catalytic action, are recyclable and show higher catalytic activity and turnover frequency than the corresponding non polymer-bound complexes. EPR and (51)V NMR spectroscopy was used to characterise methanolic solutions of 3 and 4 and to identify species formed upon addition of H(2)O(2) and/or acid and/or methyl phenyl sulfide.

Quasi-static axial crushes on woven jute/polyester AA6063T52 composite tubes

NASA Astrophysics Data System (ADS)

Othman, A.; Ismail, AE

2018-04-01

Quasi-static axial loading have been studied in this paper to determine the behaviour of jute/polyester wrapped on aluminium alloy 6063T52. The filler material also was include into crush box specimen, which is polyurethane (PU) and polystyrene (PE) rigid foam at ranging 40 and 45 kg/m3 densities. All specimen profile was fabricated using hand layup techniques and the length of each specimen were fixed at 100 mm as well as diameter and width of the tube at 50.8 mm. The two types of tubular cross-section were studied of round and square thin-walled profiles and the angle of fibre at 450 were analysed for four layers. Thin walled of aluminium was 1.9 mm and end frontal of each specimen of composite were chamfered at 450 to prevent catastrophic failure mode. The specific absorbed energy (SEA) and crush force efficiency (CFE) were analyses for each specimen to see the behaviour on jute/polyester wrapped on metallic structure can give influence the energy management for automotive application. Result show that the four layers’ jute/polyester with filler material show significant value in term of specific absorbed energy compared empty and polyurethane profiles higher 26.66% for empty and 15.19% compared to polyurethane profiles. It has been found that the thin walled square profile of the jute/polyester tubes with polystyrene foam-filled is found higher respectively 27.42% to 13.13% than empty and polyurethane (PU) foam tubes. An introduce filler material onto thin walled composite profiles gave major advantage increases the mean axial load of 31.87% from 32.94 kN to 48.35 kN from empty to polystyrene thin walled round jute/polyester profiles and 31.7% from 23.11 KN to 33.84 kN from empty to polystyrene thin walled square jute/polyester profiles. Failure mechanisms of the axially loaded composite tubes were also observed and discussed.

Covalent bonding of antibodies of polystyrene latex beads: A concept

NASA Technical Reports Server (NTRS)

Tenoso, H. J.; Smith, D. G.

1972-01-01

Technique facilitates purification of vaccines and production of immunoadsorption columns exhibiting relatively long stability. Information interests biochemists, medical researchers, and pharmaceutical manufacturers.

Rapid detection of trace amounts of surfactants using nanoparticles in fluorometric assays

NASA Astrophysics Data System (ADS)

Härmä, Harri; Laakso, Susana; Pihlasalo, Sari; Hänninen, Pekka; Faure, Bertrand; Rana, Subhasis; Bergström, Lennart

2010-01-01

Rapid microtiter assays that utilize the time-resolved fluorescence resonance energy transfer or quenching of dye-labeled proteins adsorbed onto the surfaces of polystyrene or maghemite nanoparticles have been developed for the detection and quantification of trace amounts of surfactants at concentrations down to 10 nM.Rapid microtiter assays that utilize the time-resolved fluorescence resonance energy transfer or quenching of dye-labeled proteins adsorbed onto the surfaces of polystyrene or maghemite nanoparticles have been developed for the detection and quantification of trace amounts of surfactants at concentrations down to 10 nM. Electronic supplementary information (ESI) available: Experimental details and Fig. S1 and S2. See DOI: 10.1039/b9nr00172g

Molecular differences between deuterated and protonated polystyrenes using reversed-phase high-performance liquid chromatography.

PubMed

Kayillo, Sindy; Gray, Michael J; Shalliker, R Andrew; Dennis, Gary R

2005-05-06

Isotopic substitution is a technique used to highlight particular bonds within a molecule for kinetic, spectroscopic and structure analysis. It is presumed that although some properties such as stretching frequencies will not be the same for substituted analogues, the chemical interactions will not vary appreciably as a function of labelling. Reversed-phase liquid chromatography has been used to demonstrate that there are significant differences between the chromatographic behaviour of a sequence of deuterated and protonated oligomeric polystyrenes. Two-dimensional reversed-phase liquid chromatography was used to show that even the diasteromers of the oligomers (n = 5) have retention mechanisms that are dependent on the subtle changes to the molecular conformation and electronic structure, which are a consequence of deuteration.

Synthesis of Dibenzo[hi,st]ovalene and Its Amplified Spontaneous Emission in a Polystyrene Matrix.

PubMed

Paternò, Giuseppe M; Chen, Qiang; Wang, Xiao-Ye; Liu, Junzhi; Motti, Silvia G; Petrozza, Annamaria; Feng, Xinliang; Lanzani, Guglielmo; Müllen, Klaus; Narita, Akimitsu; Scotognella, Francesco

2017-06-06

A large number of graphene molecules, or large polycyclic aromatic hydrocarbons (PAHs), have been synthesized and display various optoelectronic properties. Nevertheless, their potential for application in photonics has remained largely unexplored. Herein, we describe the synthesis of a highly luminescent and stable graphene molecule, namely a substituted dibenzo[hi,st]ovalene (DBO 1), with zigzag edges and elucidate its promising optical-gain properties by means of ultrafast transient absorption spectroscopy. Upon incorporation of DBO into an inert polystyrene matrix, amplified stimulated emission can be observed with a relatively low power threshold (ca. 60 μJ cm -2 ), thus highlighting its high potential for lasing applications. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Improving surface-enhanced Raman scattering effect using gold-coated hierarchical polystyrene bead substrates modified with postgrowth microwave treatment.

PubMed

Yuen, Clement; Zheng, Wei; Huang, Zhiwei

2008-01-01

We report a novel postgrowth microwave heating implementation by selectively modifying hierarchical polystyrene (PS) bead substrates coated with gold (Au) films to effectively improve the surface-enhanced Raman scattering (SERS) effect on the analytes. The SERS signal of probe molecule rhodamine 6G (Rh 6G) on the microwave-treated Au-PS substrates can be improved by 10-fold, while the detection limit of Rh 6G in concentration can be enhanced by two orders of magnitude compared to the as-growth substrates. The high-quality SERS spectrum of saliva can also be acquired using the modified substrates, demonstrating the potential for the realization of the high-performance SERS substrates for biomedical applications.

Polystyrene Foam EOS as a Function of Porosity and Fill Gas

NASA Astrophysics Data System (ADS)

Mulford, Roberta; Swift, Damian

2009-06-01

An accurate EOS for polystyrene foam is necessary for analysis of numerous experiments in shock compression, inertial confinement fusion, and astrophysics. Plastic to gas ratios vary between various samples of foam, according to the density and cell-size of the foam. A matrix of compositions has been investigated, allowing prediction of foam response as a function of the plastic-to-air ratio. The EOS code CHEETAH allows participation of the air in the decomposition reaction of the foam, Differences between air-filled, nitrogen-blown, and CO2-blown foams are investigated, to estimate the importance of allowing air to react with plastic products during decomposition. Results differ somewhat from the conventional EOS, which are generated from values for plastic extrapolated to low densities.

Dispersion Polymerization of Polystyrene Particles Using Alcohol as Reaction Medium

NASA Astrophysics Data System (ADS)

Cho, Young-Sang; Shin, Cheol Hwan; Han, Sujin

2016-02-01

In this study, monodisperse polystyrene nanospheres were prepared by dispersion polymerization using alcohol as reaction medium to prepare colloidal clusters of the latex beads. Polyvinylpyrrolidone (PVP) and 2-(methacryloyloxy)ethyltrimethylammonium chloride (MTC) were used as dispersion stabilizer and comonomer, respectively. The particle size could be controlled by adjusting the reactant compositions such as the amount of stabilizer, comonomer, and water in the reactant mixture. The size and monodispersity of the polymeric particles could be also controlled by changing the reaction medium with different alcohols other than ethanol or adjusting the polymerization temperature. The synthesized particles could be self-organized inside water-in-oil emulsion droplets by evaporation-driven self-assembly to produce colloidal clusters of the polymeric nanospheres.

Fitting the low-frequency Raman spectra to boson peak models: glycerol, triacetin and polystyrene

NASA Astrophysics Data System (ADS)

Kirillov, S. A.; Perova, T. S.; Faurskov Nielsen, O.; Praestgaard, E.; Rasmussen, U.; Kolomiyets, T. M.; Voyiatzis, G. A.; Anastasiadis, S. H.

1999-04-01

A computational approach was elaborated to explicitly account for the Rayleigh line wing, the Boson peak and vibrational contributions to the low-frequency Raman spectra of amorphous solids and viscous liquids. It was shown that the low-frequency Raman spectra of glycerol and polystyrene consist of the Rayleigh contribution of Lorentzian form and the Boson peak which profile follows the predictions of the theory by Martin and Brenig in the version by Malinovsky and Sokolov. In the case of triacetin, the Boson peaks decay faster in their high-frequency side than the above theory predicts. Their form can be successfully modeled with a newly introduced empirical function intermediate between the Martin-Brenig and Malinovsky-Sokolov predictions.

Tidbits for the synthesis of bis(2-sulfanylethyl)amido (SEA) polystyrene resin, SEA peptides and peptide thioesters.

PubMed

Ollivier, Nathalie; Raibaut, Laurent; Blanpain, Annick; Desmet, Rémi; Dheur, Julien; Mhidia, Reda; Boll, Emmanuelle; Drobecq, Hervé; Pira, Silvain L; Melnyk, Oleg

2014-02-01

Protein total chemical synthesis enables the atom-by-atom control of the protein structure and therefore has a great potential for studying protein function. Native chemical ligation of C-terminal peptide thioesters with N-terminal cysteinyl peptides and related methodologies are central to the field of protein total synthesis. Consequently, methods enabling the facile synthesis of peptide thioesters using Fmoc-SPPS are of great value. Herein, we provide a detailed protocol for the preparation of bis(2-sulfanylethyl)amino polystyrene resin as a starting point for the synthesis of C-terminal bis(2-sulfanylethyl)amido peptides and of peptide thioesters derived from 3-mercaptopropionic acid. Copyright © 2013 European Peptide Society and John Wiley & Sons, Ltd.

Urea photosynthesis inside polyelectrolyte capsules: effect of confined media.

PubMed

Shchukin, Dmitry G; Möhwald, Helmuth

2005-06-07

The influence of the restricted volume of poly(styrene sulfonate)/poly(allylamine hydrochloride) capsules of different size (2.2, 4.2, and 8.1 microm) on the TiO2-assisted photosynthesis of urea from inorganic precursors (CO2 and NO(3-)) in aqueous solution was demonstrated. Poly(vinyl alcohol) was employed as electron donor to facilitate the photosynthetic process. Decreasing the size of the confined microvolume of polyelectrolyte capsules accelerates the NO(3-) photoreduction, which is a limiting stage of the urea photosynthesis and, correspondingly, increases the efficiency of urea production. The highest yield of urea photosynthesis (37%) was achieved for Cu-modified TiO2 nanoparticles encapsulated inside 2.2 microm poly(styrene sulfonate)/poly(allylamine hydrochloride) capsules.

Ultrathin epidermal strain sensor based on an elastomer nanosheet with an inkjet-printed conductive polymer

NASA Astrophysics Data System (ADS)

Tetsu, Yuma; Yamagishi, Kento; Kato, Akira; Matsumoto, Yuya; Tsukune, Mariko; Kobayashi, Yo; Fujie, Masakatsu G.; Takeoka, Shinji; Fujie, Toshinori

2017-08-01

To minimize the interference that skin-contact strain sensors cause natural skin deformation, physical conformability to the epidermal structure is critical. Here, we developed an ultrathin strain sensor made from poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) inkjet-printed on a polystyrene-polybutadiene-polystyrene (SBS) nanosheet. The sensor, whose total thickness and gauge factor were ˜1 µm and 0.73 ± 0.10, respectively, deeply conformed to the epidermal structure and successfully detected the small skin strain (˜2%) while interfering minimally with the natural deformation of the skin. Such an epidermal strain sensor will open a new avenue for precisely detecting the motion of human skin and artificial soft-robotic skin.

Electrokinetic properties of polymer colloids

NASA Technical Reports Server (NTRS)

Micale, F. J.; Fuenmayor, D. Y.

1986-01-01

The surface of polymer colloids, especially polystyrene latexes, were modified for the purpose of controlling the electrokinetic properties of the resulting colloids. Achievement required a knowledge of electrical double layer charging mechanism, as a function of the electrolyte conditions, at the polymer/water interface. The experimental approach is to control the recipe formulation in the emulsion polymerization process so as to systematically vary the strong acid group concentration on the surface of the polymer particles. The electrophoretic mobility of these model particles will then be measured as a function of surface group concentration and as a function of electrolyte concentration and type. An effort was also made to evaluate the electrophoretic mobility of polystyrene latexes made in space and to compare the results with latexes made on the ground.

Comparison of methods for extraction of ethyl carbamate from alcoholic beverages in gas chromatography/mass spectrometry analysis.

PubMed

Mirzoian, Armen; Mabud, Abdul

2006-01-01

A procedure to analyze ethyl carbamate (EC) by gas chromatography/mass spectrometry was optimized and validated. Deuterated EC (d5-EC) was added to the samples as an internal standard followed by extraction with polystyrene crosslinked polystyrene cartridges using minimal volumes of ethyl acetate. The EC response was measured in selective ion monitoring (SIM) mode and found to be linear in the range between the limit of quantitation (10 micro/L) and 1000 microg/L. EC recoveries varied from 92 to 112%, with the average value of 100 +/- 8%. The procedure compared well (r2 = 0.9970) with the existing AOAC Official Method with the added benefits of minimal solvent usage and reduced matrix interferences.

Polystyrene-based Hollow Microsphere Synthesized by γ-ray Irradiation-assisted Polymerization and Self-Assembly and Its Application in Detection of Ionizing Radiation

NASA Astrophysics Data System (ADS)

Fan, Wenhui; Li, Qing; Hu, Liang; Yan, Siqi; Wen, Wanxin; Chai, Zhifang; Liu, Hanzhou

2017-01-01

To simply and multitudinously synthesize hollow microspheres in a pure system is important for relevant research and application. Here, a simple and novel one-pot synthetic strategy to prepare polystyrene (PS) hollow microspheres via irradiation-assisted free-radical polymerizing and self-assembly (IFPS) approach under γ-ray irradiation with no additives introduced into the system is presented. And PS/2,5-Diphenyloxazole (PPO) fluorescent microspheres have been prepared successfully by IFPS reaction, which can be used as scintillators for the detection of ionizing radiation. A linear relationship between emitted luminescence and dose-activity in water is obtained, which suggests that composite microspheres could be used as liquid scintillation in specific environment.

The effect of electron beam irradiation on the mechanical properties of pineapple leaf fibre (PALF) reinforced high impact polystyrene (HIPS) composites

NASA Astrophysics Data System (ADS)

Siregar, J. P.; Sapuan, S. M.; Rahman, M. Z. A.; Zaman, H. M. D. K.

2010-05-01

The effects of electron beam irradiation on the mechanical properties of pineapple leaf fibre reinforced high impact polystyrene (HIPS) composites were studied. Two types of crosslinking agent that has been used in this study were trimethylolpropane triacrylate (TMPTA) and tripropylene gylcol diacrylate (TPGDA). A 50 wt.% of PALF was blended with HIPS and crosslinking agent using Brabender melt mixer at 165 °C. The composites were then irradiated using a 3 MeV electron beam accelerator with dosage of 0-100 kGy. The tensile strength, tensile modulus, flexural strength, flexural modulus, notched and unnotched impat and hardness of composites were measured and the effects of crosslinking agent were also compared.

Cellulose hydrogenolysis with the use of the catalysts supported on hypercrosslinked polystyrene

NASA Astrophysics Data System (ADS)

Sulman, E. M.; Matveeva, V. G.; Manaenkov, O. V.; Filatova, A. E.; Kislitza, O. V.; Doluda, V. Yu.; Rebrov, E. V.; Sidorov, A. I.; Shimanskaya, E. I.

2016-11-01

The study presents the results of cellulose hydrolytic hydrogenation process in subcritical water in the presence of Ru-containing catalysts based on hypercrosslinked polystyrene (HPS) MN-270 and its functionalized analogues: NH2-HPS (MN-100) and SO3H-HPS (MN-500). It was shown that the replacement of the traditional support (carbon) by HPS increases the yield of the main cellulose conversion products - polyols - important intermediates for the chemical industry. The catalysts were characterized using transmission electron microscopy (TEM), high resolution TEM, and porosity measurements. Catalytic studies demonstrated that the catalyst containing 1.0% Ru and based on MN-270 is the most active. The total yield of sorbitol and mannitol was 50% on the average at 85% cellulose conversion.

High Stability Pentacene Transistors Using Polymeric Dielectric Surface Modifier.

PubMed

Wang, Xiaohong; Lin, Guangqing; Li, Peng; Lv, Guoqiang; Qiu, Longzhen; Ding, Yunsheng

2015-08-01

1,6-bis(trichlorosilyl)hexane (C6Cl), polystyrene (PS), and cross-linked polystyrene (CPS) were investigated as gate dielectric modified layers for high performance organic transistors. The influence of the surface energy, roughness and morphology on the charge transport of the organic thin-film transistors (OTFTs) was investigated. The surface energy and roughness both affect the grain size of the pentacene films which will control the charge carrier mobility of the devices. Pentacene thin-film transistors fabricated on the CPS modified dielectric layers exhibited charge carrier mobility as high as 1.11 cm2 V-1 s-1. The bias stress stability for the CPS devices shows that the drain current only decays 1% after 1530 s and the mobility never decreases until 13530 s.

Accurate Size and Size-Distribution Determination of Polystyrene Latex Nanoparticles in Aqueous Medium Using Dynamic Light Scattering and Asymmetrical Flow Field Flow Fractionation with Multi-Angle Light Scattering

PubMed Central

Kato, Haruhisa; Nakamura, Ayako; Takahashi, Kayori; Kinugasa, Shinichi

2012-01-01

Accurate determination of the intensity-average diameter of polystyrene latex (PS-latex) by dynamic light scattering (DLS) was carried out through extrapolation of both the concentration of PS-latex and the observed scattering angle. Intensity-average diameter and size distribution were reliably determined by asymmetric flow field flow fractionation (AFFFF) using multi-angle light scattering (MALS) with consideration of band broadening in AFFFF separation. The intensity-average diameter determined by DLS and AFFFF-MALS agreed well within the estimated uncertainties, although the size distribution of PS-latex determined by DLS was less reliable in comparison with that determined by AFFFF-MALS. PMID:28348293

Preparative purification of polyethylene glycol derivatives with polystyrene-divinylbenzene beads as chromatographic packing.

PubMed

Yu, Pengzhan; Li, Xingqi; Li, Xiunan; Lu, Xiuling; Ma, Guanghui; Su, Zhiguo

2007-10-15

A clear and powerful chromatographic approach to purify polyethylene glycol derivatives at a preparative scale was reported, which was based on the polystyrene-divinylbenzene beads with ethanol/water as eluants. The validity of this method was verified with the reaction mixture of mPEG-Glu and mPEG propionaldehyde diethylacetal (ALD-PEG) as the model. The target products were one-step achieved with the purity of >99% on the polymer resins column at gram scale. The method developed was free from such disadvantages as utility of toxic solvent and narrow application scope, which was combined with conventional approaches. The method developed provided an appealing and attractive alternative methods for purification of PEG derivatives at a preparative scale.

Wavelet transform fast inverse light scattering analysis for size determination of spherical scatterers

PubMed Central

Ho, Derek; Kim, Sanghoon; Drake, Tyler K.; Eldridge, Will J.; Wax, Adam

2014-01-01

We present a fast approach for size determination of spherical scatterers using the continuous wavelet transform of the angular light scattering profile to address the computational limitations of previously developed sizing techniques. The potential accuracy, speed, and robustness of the algorithm were determined in simulated models of scattering by polystyrene beads and cells. The algorithm was tested experimentally on angular light scattering data from polystyrene bead phantoms and MCF-7 breast cancer cells using a 2D a/LCI system. Theoretical sizing of simulated profiles of beads and cells produced strong fits between calculated and actual size (r2 = 0.9969 and r2 = 0.9979 respectively), and experimental size determinations were accurate to within one micron. PMID:25360350

Development of corn silk as a biocarrier for Zymomonas mobilis biofilms in ethanol production from rice straw.

PubMed

Todhanakasem, Tatsaporn; Tiwari, Rashmi; Thanonkeo, Pornthap

2016-01-01

Z. mobilis cell immobilization has been proposed as an effective means of improving ethanol production. In this work, polystyrene and corn silk were used as biofilm developmental matrices for Z. mobilis ethanol production with rice straw hydrolysate as a substrate. Rice straw was hydrolyzed by dilute sulfuric acid (H2SO4) and enzymatic hydrolysis. The final hydrolysate contained furfural (271.95 ± 76.30 ppm), 5-hydroxymethyl furfural (0.07 ± 0.00 ppm), vanillin (1.81 ± 0.00 ppm), syringaldehyde (5.07 ± 0.83 ppm), 4-hydroxybenzaldehyde (4-HB) (2.39 ± 1.20 ppm) and acetic acid (0.26 ± 0.08%). Bacterial attachment or biofilm formation of Z. mobilis strain TISTR 551 on polystyrene and delignified corn silk carrier provided significant ethanol yields. Results showed up to 0.40 ± 0.15 g ethanol produced/g glucose consumed when Z. mobilis was immobilized on a polystyrene carrier and 0.51 ± 0.13 g ethanol produced/g glucose consumed when immobilized on delignified corn silk carrier under batch fermentation by Z. mobilis TISTR 551 biofilm. The higher ethanol yield from immobilized, rather than free living, Z. mobilis could possibly be explained by a higher cell density, better control of anaerobic conditions and higher toxic tolerance of Z. mobilis biofilms over free cells.

(Quasi-) 2D aggregation of polystyrene-b-dextran at the air-water interface.

PubMed

Bosker, Wouter T E; Cohen Stuart, Martien A; Norde, Willem

2013-02-26

Polystyrene-b-dextran (PS-b-Dextran) copolymers can be used to prepare dextran brushes at solid surfaces, applying Langmuir-Blodgett deposition. When recording the interfacial pressure versus area isotherms of a PS-b-Dextran monolayer, time-dependent hysteresis was observed upon compression and expansion. We argue that this is due to (quasi-) 2D aggregation of the copolymer at the air-water surface, with three contributions. First, at large area per molecule, a zero surface pressure is measured; we ascribe this to self-assembly of block copolymers into surface micelles. At intermediate area we identify a second regime ("desorption regime") where aggregation into large patches occurs due to van der Waals attraction between PS blocks. At high surface pressure ("brush regime") we observe hysteretic behavior attributed to H-bonding between dextran chains. When compared to hysteresis of other amphiphilic diblock copolymers (also containing PS, e.g., polystyrene-b-poly(ethylene oxide)) a general criterion can be formulated concerning the extent of hysteresis: when the hydrophobic (PS) block is of equal size as (or bigger than) the hydrophilic block, the hysteresis is maximal. The (quasi-) 2D aggregation of PS-b-Dextran has significant implications for the preparation of dextran brushes at solid surfaces using Langmuir-Blodgett deposition. For each grafting density the monolayer needs to relax, up to several hours, prior to transfer.

How osmolytes influence hydrophobic polymer conformations: A unified view from experiment and theory.

PubMed

Mondal, Jagannath; Halverson, Duncan; Li, Isaac T S; Stirnemann, Guillaume; Walker, Gilbert C; Berne, Bruce J

2015-07-28

It is currently the consensus belief that protective osmolytes such as trimethylamine N-oxide (TMAO) favor protein folding by being excluded from the vicinity of a protein, whereas denaturing osmolytes such as urea lead to protein unfolding by strongly binding to the surface. Despite there being consensus on how TMAO and urea affect proteins as a whole, very little is known as to their effects on the individual mechanisms responsible for protein structure formation, especially hydrophobic association. In the present study, we use single-molecule atomic force microscopy and molecular dynamics simulations to investigate the effects of TMAO and urea on the unfolding of the hydrophobic homopolymer polystyrene. Incorporated with interfacial energy measurements, our results show that TMAO and urea act on polystyrene as a protectant and a denaturant, respectively, while complying with Tanford-Wyman preferential binding theory. We provide a molecular explanation suggesting that TMAO molecules have a greater thermodynamic binding affinity with the collapsed conformation of polystyrene than with the extended conformation, while the reverse is true for urea molecules. Results presented here from both experiment and simulation are in line with earlier predictions on a model Lennard-Jones polymer while also demonstrating the distinction in the mechanism of osmolyte action between protein and hydrophobic polymer. This marks, to our knowledge, the first experimental observation of TMAO-induced hydrophobic collapse in a ternary aqueous system.

How osmolytes influence hydrophobic polymer conformations: A unified view from experiment and theory

PubMed Central

Mondal, Jagannath; Halverson, Duncan; Li, Isaac T. S.; Stirnemann, Guillaume; Walker, Gilbert C.; Berne, Bruce J.

2015-01-01

It is currently the consensus belief that protective osmolytes such as trimethylamine N-oxide (TMAO) favor protein folding by being excluded from the vicinity of a protein, whereas denaturing osmolytes such as urea lead to protein unfolding by strongly binding to the surface. Despite there being consensus on how TMAO and urea affect proteins as a whole, very little is known as to their effects on the individual mechanisms responsible for protein structure formation, especially hydrophobic association. In the present study, we use single-molecule atomic force microscopy and molecular dynamics simulations to investigate the effects of TMAO and urea on the unfolding of the hydrophobic homopolymer polystyrene. Incorporated with interfacial energy measurements, our results show that TMAO and urea act on polystyrene as a protectant and a denaturant, respectively, while complying with Tanford–Wyman preferential binding theory. We provide a molecular explanation suggesting that TMAO molecules have a greater thermodynamic binding affinity with the collapsed conformation of polystyrene than with the extended conformation, while the reverse is true for urea molecules. Results presented here from both experiment and simulation are in line with earlier predictions on a model Lennard–Jones polymer while also demonstrating the distinction in the mechanism of osmolyte action between protein and hydrophobic polymer. This marks, to our knowledge, the first experimental observation of TMAO-induced hydrophobic collapse in a ternary aqueous system. PMID:26170324

Integration of nondegradable polystyrene and degradable gelatin in a core–sheath nanofibrous patch for pelvic reconstruction

PubMed Central

Ge, Liangpeng; Li, Qingtao; Jiang, Junzi; You, Xiaoyan; Liu, Zuohua; Zhong, Wen; Huang, Yong; Xing, Malcolm MQ

2015-01-01

Pelvic organ prolapse (POP) is a serious health issue affecting many adult women. Complications of POP include pelvic pressure, pelvic pain, and problems in emptying their bowels or bladder. Sometimes, POP may even cause urinary outflow obstruction and lead to bladder or kidney infections. Currently, synthetic and naturally derived materials have been chosen for treatment of POP to reduce the high recurrence rates after surgical interventions. However, existing materials for POP treatment cannot meet the clinical requirements in terms of biocompatibility, mechanics, and minimal risk of rejection. Especially, erosion in synthetic polymers and rapid degradation in natural polymers limit their further applications in clinics. To address these concerns, we report a novel POP replacement using core–sheath polystyrene/gelatin electrospun nanofiber mesh. The outside gelatin sheath provides a hydrophilic surface and implantable integrity between host and guest, while the inner PS core offers the necessary mechanical support. The composite mesh shows graft accommodation in pelvic submucosa after implantation in vivo, as shown in hematoxylin–eosin staining and T helper cell phenotype and macrophage phenotype stainings. Qualitative analysis of inducible nitric oxide synthase, arginase, interferon-γ, and interleukin-10 gene expressions also indicates that the implanted composite mesh switches to accommodation mode 2 weeks postimplantation. Thus, these novel core–sheath polystyrene/gelatin nanofibrous membranes are promising in pelvic reconstruction. PMID:25995629

Ultrasonic wave velocity measurement in small polymeric and cortical bone specimens

NASA Technical Reports Server (NTRS)

Kohles, S. S.; Bowers, J. R.; Vailas, A. C.; Vanderby, R. Jr

1997-01-01

A system was refined for the determination of the bulk ultrasonic wave propagation velocity in small cortical bone specimens. Longitudinal and shear wave propagations were measured using ceramic, piezoelectric 20 and 5 MHz transducers, respectively. Results of the pulse transmission technique were refined via the measurement of the system delay time. The precision and accuracy of the system were quantified using small specimens of polyoxymethylene, polystyrene-butadiene, and high-density polyethylene. These polymeric materials had known acoustic properties, similarity of propagation velocities to cortical bone, and minimal sample inhomogeneity. Dependence of longitudinal and transverse specimen dimensions upon propagation times was quantified. To confirm the consistency of longitudinal wave propagation in small cortical bone specimens (< 1.0 mm), cut-down specimens were prepared from a normal rat femur. Finally, cortical samples were prepared from each of ten normal rat femora, and Young's moduli (Eii), shear moduli (Gij), and Poisson ratios (Vij) were measured. For all specimens (bone, polyoxymethylene, polystyrene-butadiene, and high-density polyethylene), strong linear correlations (R2 > 0.997) were maintained between propagation time and distance throughout the size ranges down to less than 0.4 mm. Results for polyoxymethylene, polystyrene-butadiene, and high-density polyethylene were accurate to within 5 percent of reported literature values. Measurement repeatability (precision) improved with an increase in the wave transmission distance (propagating dimension). No statistically significant effect due to the transverse dimension was detected.

The impact of polystyrene microplastics on feeding, function and fecundity in the marine copepod Calanus helgolandicus.

PubMed

Cole, Matthew; Lindeque, Pennie; Fileman, Elaine; Halsband, Claudia; Galloway, Tamara S

2015-01-20

Microscopic plastic debris, termed “microplastics”, are of increasing environmental concern. Recent studies have demonstrated that a range of zooplankton, including copepods, can ingest microplastics. Copepods are a globally abundant class of zooplankton that form a key trophic link between primary producers and higher trophic marine organisms. Here we demonstrate that ingestion of microplastics can significantly alter the feeding capacity of the pelagic copepod Calanus helgolandicus. Exposed to 20 μm polystyrene beads (75 microplastics mL(–1)) and cultured algae ([250 μg C L(–1)) for 24 h, C. helgolandicus ingested 11% fewer algal cells (P = 0.33) and 40% less carbon biomass (P < 0.01). There was a net downward shift in the mean size of algal prey consumed (P < 0.001), with a 3.6 fold increase in ingestion rate for the smallest size class of algal prey (11.6–12.6 μm), suggestive of postcapture or postingestion rejection. Prolonged exposure to polystyrene microplastics significantly decreased reproductive output, but there were no significant differences in egg production rates, respiration or survival. We constructed a conceptual energetic (carbon) budget showing that microplastic-exposed copepods suffer energetic depletion over time. We conclude that microplastics impede feeding in copepods, which over time could lead to sustained reductions in ingested carbon biomass.

Electroconductive Composites from Polystyrene Block Copolymers and Cu–Alumina Filler

PubMed Central

Nadeem, QuratulAin; Fatima, Tasneem; Prinsen, Pepijn; ur Rehman, Aziz; Gill, Rohama; Mahmood, Rashid; Luque, Rafael

2016-01-01

Technological advancements and development of new materials may lead to the manufacture of sustainable energy-conducting devices used in the energy sector. This research attempts to fabricate novel electroconductive and mechanically stable nanocomposites via an electroless deposition (ELD) technique using electrically insulating materials. Metallic Cu is coated onto Al2O3 by ELD, and the prepared filler is then integrated (2–14 wt %) into a matrix of polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene-graft-maleic anhydride (PS-b-(PE-r-B)-b-PS-g-MA). Considerable variations in composite phases with filler inclusion exist. The Cu crystallite growth onto Al2O3 was evaluated by X-ray diffraction (XRD) analysis and energy dispersive spectrometry (EDS). Scanning electron microscopy (SEM) depicts a uniform Cu coating on Al2O3, while homogeneous filler dispersion is exhibited in the case of composites. The electrical behavior of composites is enhanced drastically (7.7 × 10−5 S/cm) upon incorporation of Cu–Al2O3 into an insulating polymer matrix (4.4 × 10−16 S/cm). Moreover, mechanical (Young’s modulus, tensile strength and % elongation at break) and thermal (thermogravimetric analysis (TGA), derivative thermogravimetry (DTG), and differential scanning calorimetry (DSC)) properties of the nanocomposites also improve substantially. These composites are likely to meet the demands of modern high-strength electroconductive devices. PMID:28774110

Fracture Properties of Polystyrene Aggregate Concrete after Exposure to High Temperatures

PubMed Central

Tang, Waiching; Cui, Hongzhi; Tahmasbi, Soheil

2016-01-01

This paper mainly reports an experimental investigation on the residual mechanical and fracture properties of polystyrene aggregate concrete (PAC) after exposure to high temperatures up to 800 degrees Celsius. The fracture properties namely, the critical stress intensity factor (KICS), the critical crack tip opening displacement (CTODC) for the Two-Parameter Model, and the fracture energy (GF) for the Fictitious Crack Model were examined using the three-point bending notched beam test, according to the RILEM recommendations. The effects of polystyrene aggregate (PA) content and temperature levels on the fracture and mechanical properties of concrete were investigated. The results showed that the mechanical properties of PAC significantly decreased with increase in temperature level and the extent of which depended on the PA content in the mixture. However, at a very high temperature of 800 °C, all samples showed 80 percent reduction in modulus of elasticity compared to room temperature, regardless of the level of PA content. Fracture properties of control concrete (C) and PAC were influenced by temperature in a similar manner. Increasing temperature from 25 °C to 500 °C caused almost 50% reduction of the fracture energy for all samples while 30% increase in fracture energy was occurred when the temperature increased from 500 °C to 800 °C. It was found that adding more PA content in the mixture lead to a more ductile behaviour of concrete. PMID:28773752

Eradication of high viable loads of Listeria monocytogenes contaminating food-contact surfaces

PubMed Central

de Candia, Silvia; Morea, Maria; Baruzzi, Federico

2015-01-01

This study demonstrates the efficacy of cold gaseous ozone treatments at low concentrations in the eradication of high Listeria monocytogenes viable cell loads from glass, polypropylene, stainless steel, and expanded polystyrene food-contact surfaces. Using a step by step approach, involving the selection of the most resistant strain-surface combinations, 11 Listeria sp. strains resulted inactivated by a continuous ozone flow at 1.07 mg m-3 after 24 or 48 h of cold incubation, depending on both strain and surface evaluated. Increasing the inoculum level to 9 log CFU coupon-1, the best inactivation rate was obtained after 48 h of treatment at 3.21 mg m-3 ozone concentration when cells were deposited onto stainless steel and expanded polystyrene coupons, resulted the most resistant food-contact surfaces in the previous assays. The addition of naturally contaminated meat extract to a high load of L. monocytogenes LMG 23775 cells, the most resistant strain out of the 11 assayed Listeria sp. strains, led to its complete inactivation after 4 days of treatment. To the best of our knowledge, this is the first report describing the survival of L. monocytogenes and the effect of ozone treatment under cold storage conditions on expanded polystyrene, a commonly used material in food packaging. The results of this study could be useful for reducing pathogen cross-contamination phenomena during cold food storage. PMID:26236306

High content analysis provides mechanistic insights on the pathways of toxicity induced by amine-modified polystyrene nanoparticles.

PubMed

Anguissola, Sergio; Garry, David; Salvati, Anna; O'Brien, Peter J; Dawson, Kenneth A

2014-01-01

The fast-paced development of nanotechnology needs the support of effective safety testing. We have developed a screening platform measuring simultaneously several cellular parameters for exposure to various concentrations of nanoparticles (NPs). Cell lines representative of different organ cell types, including lung, endothelium, liver, kidney, macrophages, glia, and neuronal cells were exposed to 50 nm amine-modified polystyrene (PS-NH2) NPs previously reported to induce apoptosis and to 50 nm sulphonated and carboxyl-modified polystyrene NPs that were reported to be silent. All cell lines apart from Raw 264.7 executed apoptosis in response to PS-NH2 NPs, showing specific sequences of EC50 thresholds; lysosomal acidification was the most sensitive parameter. Loss of mitochondrial membrane potential and plasma membrane integrity measured by High Content Analysis resulted comparably sensitive to the equivalent OECD-recommended assays, allowing increased output. Analysis of the acidic compartments revealed good cerrelation between size/fluorescence intensity and dose of PS-NH2 NPs applied; moreover steatosis and phospholipidosis were observed, consistent with the lysosomal alterations revealed by Lysotracker green; similar responses were observed when comparing astrocytoma cells with primary astrocytes. We have established a platform providing mechanistic insights on the response to exposure to nanoparticles. Such platform holds great potential for in vitro screening of nanomaterials in highthroughput format.

Control of the Biofilms Formed by Curli- and Cellulose-Expressing Shiga Toxin-Producing Escherichia coli Using Treatments with Organic Acids and Commercial Sanitizers.

PubMed

Park, Yoen Ju; Chen, Jinru

2015-05-01

Biofilms are a mixture of bacteria and extracellular products secreted by bacterial cells and are of great concern to the food industry because they offer physical, mechanical, and biological protection to bacterial cells. This study was conducted to quantify biofilms formed by different Shiga toxin-producing Escherichia coli (STEC) strains on polystyrene and stainless steel surfaces and to determine the effectiveness of sanitizing treatments in control of these biofilms. STEC producing various amounts of cellulose (n = 6) or curli (n = 6) were allowed to develop biofilms on polystyrene and stainless steel surfaces at 28°C for 7 days. The biofilms were treated with 2% acetic or lactic acid and manufacturer-recommended concentrations of acidic or alkaline sanitizers, and residual biofilms were quantified. Treatments with the acidic and alkaline sanitizers were more effective than those with the organic acids for removing the biofilms. Compared with their counterparts, cells expressing a greater amount of cellulose or curli formed more biofilm mass and had greater residual mass after sanitizing treatments on polystyrene than on stainless steel. Research suggests that the organic acids and sanitizers used in the present study differed in their ability to control biofilms. Bacterial surface components and cell contact surfaces can influence both biofilm formation and the efficacy of sanitizing treatments. These results provide additional information on control of biofilms formed by STEC.

Diffusion of liquid polystyrene into glassy poly(phenylene oxide) characterized by DSC

NASA Astrophysics Data System (ADS)

Li, Linling; Wang, Xiaoliang; Zhou, Dongshan; Xue, Gi

2013-03-01

We report a diffusion study on the polystyrene/poly(phenylene oxide) (PS/PPO) mixture consisted by the PS and PPO nanoparticles. Diffusion of liquid PS into glassy PPO (l-PS/g-PPO) is promoted by annealing the PS/PPO mixture at several temperatures below Tg of the PPO. By tracing the Tgs of the PS-rich domain behind the diffusion front using DSC, we get the relationships of PS weight fractions and diffusion front advances with the elapsed diffusion times at different diffusion temperatures using the Gordon-Taylor equation and core-shell model. We find that the plots of weight fraction of PS vs. elapsed diffusion times at different temperatures can be converted to a master curve by Time-Temperature superposition, and the shift factors obey the Arrhenius equation. Besides, the diffusion front advances of l-PS into g-PPO show an excellent agreement with the t1/2 scaling law at the beginning of the diffusion process, and the diffusion coefficients of different diffusion temperatures also obey the Arrhenius equation. We believe the diffusion mechanism for l-PS/g-PPO should be the Fickean law rather than the Case II, though there are departures of original linearity at longer diffusion times due to the limited liquid supply system. Diffusion of liquid polystyrene into glassy poly(phenylene oxide) characterized by DSC

[Influence of slime production and adhesion of Candida sp. on biofilm formation].

PubMed

Ciok-Pater, Emilia; Smolak, Przemysław; Wróblewska, Joanna; Gospodarek, Eugenia

2011-01-01

The increase of fungal infections in recent years is connected with the progress in medicine. The vast usage of biomaterials is an inseparable element of contemporary medicine but it also leads to development of infections. Yeast-like fungi Candida albicans are still the main pathogen of candidiasis. The ability to slime production and adhesion to polystyrene of Candida sp. on different surfaces can cause to form biofilm on surfaces of biomaterials used in production of catheters, drains and prosthesis. The aim of the study was to evaluate the influence of slime production and adhesion to polystyrene, of Candida sp. on biofilm formation on different biomaterials. 50 strains of Candida sp. were examined. They isolated from ill to Clinics of Anesthesiology and Intensive Therapy University Hospital No 1 of dr. A. Jurasza in Bydgoszcz. The ability to slime production was evaluated by Christensen method in modification Davenport and Branchini methods. The adhesion to polystyrene was evaluated by Richards et el method. The ability to produce biofilm biomaterials by the studied fungi was measured after 72 hours of incubation at 37 degrees C on different biomaterials. Yeast-like fungi Candida sp. fabricating slime and adhesion forming frequently biofilm on surface researched of biomaterials. Influence of chosen biological specificity ascertain on the ability to produce biofilm on surfaces of siliconized latex and polyvinylchloride.

Plastic pollution in freshwater ecosystems: macro-, meso-, and microplastic debris in a floodplain lake.

PubMed

Blettler, Martin C M; Ulla, Maria Alicia; Rabuffetti, Ana Pia; Garello, Nicolás

2017-10-23

Plastic pollution is considered an important environmental problem by the United Nations Environment Programme, and it is identified, alongside climate change, as an emerging issue that might affect biological diversity and human health. However, despite research efforts investigating plastics in oceans, relatively little studies have focused on freshwater systems. The aim of this study was to estimate the spatial distribution, types, and characteristics of macro-, meso-, and microplastic fragments in shoreline sediments of a freshwater lake. Food wrappers (mainly polypropylene and polystyrene), bags (high- and low-density polyethylene), bottles (polyethylene terephthalate), and disposable Styrofoam food containers (expanded polystyrene) were the dominant macroplastics recorded in this study. Contrary to other studies, herein macroplastic item surveys would not serve as surrogates for microplastic items. This is disadvantageous since macroplastic surveys are relatively easier to conduct. Otherwise, an average of 25 mesoplastics (mainly expanded polystyrene) and 704 microplastic particles (diverse resins) were recorded per square meter in sandy sediments. Comparisons with other studies from freshwater and marine beaches indicated similar relevance of plastic contamination, demonstrating for the first time that plastic pollution is a serious problem in the Paraná floodplain lakes. This study is also valuable from a social/educational point of view, since plastic waste has been ignored in the Paraná catchment as a pollutant problem, and therefore, the outcome of the current study is a relevant contribution for decision makers.

Using the sessile drop geometry to measure fluid and elastic block copolymer interfaces.

PubMed

Rozairo, Damith P; Croll, Andrew B

2015-02-03

There is considerable interest in the fabrication and mechanics of soft spheres and capsules because of their use in a large number of applications ranging from targeted drug delivery to cosmetically active agents. Many systems, such as lipid and block copolymer vesicles, are already finding considerable industrial use where the performance of soft spheres depends intimately on their mechanics. New advanced features such as fast cargo delivery can be realized only if they fit into the existing mechanical niche of the system in question. Here we present a model system to demonstrate how a capsule structure can be fundamentally changed while maintaining its overall mechanical response as well as a simple, universal method to measure the resulting capsule material properties. Specifically, we use confocal microscopy to adapt the sessile drop geometry to a measurement of the static properties of an ensemble of polystyrene-b-poly(ethylene oxide) (PS-PEO)-stabilized oil droplets. We then synthesize a polystyrene-b-poly(acrylic acid)-b-polystyrene (PS-PAA-PS) elastic-shell-coated emulsion drop that shows an identical deformation to the fluidlike PS-PEO droplets. Both systems, in sessile geometry, can be related to their basic material properties through appropriate modeling. We find that the elastic shell is dominated by its surface tension, easily enabling it to match the static response of a purely fluid drop.

Removal of arsenic compounds from petroliferous liquids

DOEpatents

Fish, R.H.

1984-04-06

The present invention in one aspect comprises a process for removing arsenic from petroliferous-derived liquids by contacting said liquid with a divinylbenzene-crosslinked polystyrene polymer (i.e. PS-DVB) having catechol ligands anchored to said polymer, said contacting being at an elevated temperature. In another aspect, the invention is a process for regenerating spent catecholated polystyrene polymer by removal of the arsenic bound to it from contacting petroliferous liquid in accordance with the aspect described above which regenerating process comprises: (a) treating said spent catecholated polystyrene polymer with an aqueous solution of at least one member selected from the group consisting of carbonates and bicarbonates of ammonium, alkali metals, and alkaline earth metals, said solution having a pH between about 8 and 10, and said treating being at a temperature in the range of about 20/sup 0/ to 100/sup 0/C; (b) separating the solids and liquids from each other. In a preferred embodiment the regeneration treatment is in two steps wherein step: (a) is carried out with an aqueous alcoholic carbonate solution which includes at least one lower alkyl alcohol, and, steps (c) and (d) are added. Steps (c) and (d) comprise: (c) treating the solids with an aqueous alcoholic solution of at least one ammonium, alkali or alkaline earth metal bicarbonate at a temperature in the range of about 20 to 100/sup 0/C; and (d) separating the solids from the liquids.

Effects of polystyrene microplastics on the fitness of earthworms in an agricultural soil

NASA Astrophysics Data System (ADS)

Cao, Dongdong; Wang, Xiao; Luo, Xianxiang; Liu, Guocheng; Zheng, Hao

2017-04-01

Microplastics (MPs) pollution is widespread in the environment, while the effects of MPs on the soil organisms are poorly understood. In this study, we investigated the fitness of earthworms (E. Foetida) exposed to MPs (Polystyrene, 58 μm) in soils at the concentrations of 0, 0.25, 0.5, 1 and 2% (w/w). The results showed that MPs had little effects on the fitness of earthworms under low exposure concentrations (≤ 0.5 % (w/w)), while MPs exposure with high concentrations (i.e., 1% and 2%) significantly inhibited the growth and increased the mortality of earthworms. The results indicated that the MPs pollution in soils have an adverse effect on the fitness of soil organisms, and implied the ecological risk of MPs in terrestrial ecosystems.

Detection of creatinine enriched on a surface imprinted polystyrene film using FT-ATR-IR.

PubMed

Sreenivasan, K

2006-01-01

The surface of polystyrene (PS) was chemically modified by coating a thin layer of polyaniline (PANI) by oxidizing aniline using ammonium persulfate. Affinity sites for creatinine, a clinically relevant molecule, were created in the coated layer by adding creatinine as print molecules during the oxidation. The imprinted layer adsorbed creatinine was compared to non-imprinted surface reflecting the creation of creatinine-specific sites on the surface. The equilibrium was attained rapidly, indicating that a material of this kind is suitable for sensing applications. The adsorbed creatinine on the surface was detected using the technique of Fourier transform attenuated total internal reflection infra red spectroscopy (FT-ATR-IR). The results show that molecularly imprinted surface can enrich molecules of interest and the enriched molecules can be detected using FT-IR.

The static structure and dynamics of cadmium sulfide nanoparticles within poly(styrene- block-isoprene) diblock copolymer melts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jang, Woo -Sik; Koo, Peter; Bryson, Kyle

Here, the static structure and dynamic behavior of cadmium sulfide nanoparticles suspended in block copolymer matrix are investigated using transmission electron microscopy, small-angle X-ray scattering, and X-ray photon correlation spectroscopy. The transmission electron micro- scopy study shows that cadmium sulfide nanoparticles are preferentially segregated within the polyisoprene domain of a poly(styrene- block-isoprene) diblock copolymer. For the dynamics study, X-ray photon correlation spectroscopy captures the relaxation process of cadmium sulfide nanoparticles. The measured characteristic relaxation time reveals that the observed dynamics are hyperdiffusive. The characteristic velocity and corresponding activation energy, which are hallmarks of a hyperdiffusive system, are determined from themore » relationship between the characteristic relaxation time and the wavevector.« less

Transient Cooperative Processes in Dewetting Polymer Melts.

PubMed

Chandran, Sivasurender; Reiter, Günter

2016-02-26

We compare the high velocity dewetting behavior, at elevated temperatures, of atactic polystyrene (aPS) and isotactic polystyrene (iPS) films, with the zero shear bulk viscosity (η_{bulk}) of aPS being approximately ten times larger than iPS. As expected, for aPS the apparent viscosity of the films (η_{f}) derived from high-shear dewetting is less than η_{bulk}, displaying a shear thinning behavior. Surprisingly, for iPS films, η_{f} is always larger than η_{bulk}, even at about 50 °C above the melting point, with η_{f}/η_{bulk} following an Arrhenius behavior. The corresponding activation energy of ∼160±10  kJ/mol for iPS films suggests a cooperative motion of segments which are aligned and agglomerated by fast dewetting.

The static structure and dynamics of cadmium sulfide nanoparticles within poly(styrene- block-isoprene) diblock copolymer melts

DOE PAGES

Jang, Woo -Sik; Koo, Peter; Bryson, Kyle; ...

2015-12-20

Here, the static structure and dynamic behavior of cadmium sulfide nanoparticles suspended in block copolymer matrix are investigated using transmission electron microscopy, small-angle X-ray scattering, and X-ray photon correlation spectroscopy. The transmission electron micro- scopy study shows that cadmium sulfide nanoparticles are preferentially segregated within the polyisoprene domain of a poly(styrene- block-isoprene) diblock copolymer. For the dynamics study, X-ray photon correlation spectroscopy captures the relaxation process of cadmium sulfide nanoparticles. The measured characteristic relaxation time reveals that the observed dynamics are hyperdiffusive. The characteristic velocity and corresponding activation energy, which are hallmarks of a hyperdiffusive system, are determined from themore » relationship between the characteristic relaxation time and the wavevector.« less

Immobilization of Polyoxometalates on Tailored Polymeric Surfaces.

PubMed

Aguado-Ureta, Saioa; Rodríguez-Hernández, Juan; Del Campo, Adolfo; Perez-Álvarez, Leyre; Ruiz-Rubio, Leire; Vilas, José Luis; Artetxe, Beñat; Reinoso, Santiago; Gutiérrez-Zorrilla, Juan M

2018-03-02

Herein we describe the preparation of hybrid polymer-inorganic interfaces by the immobilization of polyoxometalate nanoclusters on functionalized polymer surfaces. The polymeric surfaces were made of polystyrene- b -poly(acrylic acid)/polystyrene (PS- b -PAA/PS) blends by spin coating on a silicon wafer. The functionalization of the polymer film was obtained by interfacial migration of the amphiphilic block copolymer toward the interface upon water vapor annealing. The carboxylic acid functional groups contained in the PAA block were then employed to anchor the [Ln III (α-SiW 11 O 39 )] 5- polyoxometalates (Ln: Ce, Er). This purpose was achieved by immersing the films in aqueous solutions of the in situ-formed inorganic nanoclusters. X-ray photoelectron and confocal Raman spectroscopies, together with atomic force microscopy, confirmed the immobilization of the inorganic species at the interface.

Nanostructured magnetic particles with polystyrene and their magnetorheological applications.

PubMed

Fang, Fei Fei; Choi, Hyoung Jin

2011-03-01

Magnetorheological (MR) fluids are known to be colloidal suspensions of magnetic particles in a non-magnetic fluid, and exposure to a magnetic field transforms the fluid into a plastic-like solid in milliseconds. To improve the stability against sedimentation and uniform dispersion, two different MR candidates, soft magnetic carbonyl iron (CI) microspheres and magnetite (Fe3O4) particles were modified with polystyrene to be applied for MR fluids in this study. After modification, their unique morphology, crystalline structure and magnetic properties were examined in addition to MR performance and sedimentation characteristics. It was found that this embedded morphology not only effectively prevents direct contact of the magnetic species thus improving particle dispersion but also leads to obvious change in their density, compared with the traditional polymer coating method with a core-shell structure.

Bi-Component Nanostructured Arrays of Co Dots Embedded in Ni80Fe20 Antidot Matrix: Synthesis by Self-Assembling of Polystyrene Nanospheres and Magnetic Properties.

PubMed

Coïsson, Marco; Celegato, Federica; Barrera, Gabriele; Conta, Gianluca; Magni, Alessandro; Tiberto, Paola

2017-08-23

A bi-component nanostructured system composed by a Co dot array embedded in a Ni 80 Fe 20 antidot matrix has been prepared by means of the self-assembling polystyrene nanospheres lithography technique. Reference samples constituted by the sole Co dots or Ni 80 Fe 20 antidots have also been prepared, in order to compare their properties with those of the bi-component material. The coupling between the two ferromagnetic elements has been studied by means of magnetic and magneto-transport measurements. The Ni 80 Fe 20 matrix turned out to affect the vortex nucleation field of the Co dots, which in turn modifies the magneto-resistance behaviour of the system and its spinwave properties.

Triblock copolyampholytes from 5-(N,N-dimethyl amino)isoprene styrene, and methacrylic acid: Synthesis and solution properties

NASA Astrophysics Data System (ADS)

Bieringer, R.; Abetz, V.; Müller, A. H. E.

ABC triblock copolymers of the type poly[5-(N,N-dimethyl amino)isoprene]-block-polystyrene-block-poly(tert-butyl methacrylate) (AiST) were synthesized and hydrolyzed to yield poly[5-(N,N-dimethyl amino)isoprene]-block-polystyrene-block-poly(methacrylic acid) (AiSA) triblock copolyampholytes. Due to a complex solubility behavior the solution properties of these materials had to be investigated in THF/water solvent mixtures. Potentiometric titrations of AiSA triblock copolyampholytes showed two inflection points with the A block being deprotonated prior to the Ai hydrochloride block thus forming a polyzwitterion at the isoelectric point (iep). The aggregation behavior was studied by dynamic light scattering (DLS) and freeze-fracture/transmission electron microscopy (TEM). Large vesicular structures with almost pH-independent radii were observed.

Porous double-layer polymer tubing for the potential use in heterogeneous continuous flow reactions.

PubMed

Herwig, Gordon; Hornung, Christian H; Peeters, Gary; Ebdon, Nicholas; Savage, G Paul

2014-12-24

Functional polymer tubing with an OD of 1/16 or 1/8 in. was fabricated by a simple polymer coextrusion process. The tubing was made of an outer impervious polypropylene layer and an inner layer, consisting of a blend of a functional polymer, polyethylene-co-methacrylic acid, and a sacrificial polymer, polystyrene. After a simple solvent leaching step using common organic solvents, the polystyrene was removed, leaving behind a porous inner layer that contains functional carboxylic acid groups, which could then be used for the immobilization of target molecules. Solution-phase reactions using amines or isocyanates have proven successful for the immobilization of a series of small molecules and polymers. This flexible multilayered functional tubing can be easily cut to the desired length and connected via standard microfluidic fittings.

Cationic Biomimetic Particles of Polystyrene/Cationic Bilayer/Gramicidin for Optimal Bactericidal Activity.

PubMed

Xavier, Gabriel R S; Carmona-Ribeiro, Ana M

2017-12-02

Nanostructured particles of polystyrene sulfate (PSS) covered by a cationic lipid bilayer of dioctadecyldimethylammonium bromide (DODAB) incorporated gramicidin D (Gr) yielding optimal and broadened bactericidal activity against both Escherichia coli and Staphylococcus aureus . The adsorption of DODAB/Gr bilayer onto PSS nanoparticles (NPs) increased the zeta-average diameter by 8-10 nm, changed the zeta-potential of the NPs from negative to positive, and yielded a narrow size distributions for the PSS/DODAB/Gr NPs, which displayed broad and maximal microbicidal activity at very small concentrations of the antimicrobials, namely, 0.057 and 0.0057 mM DODAB and Gr, respectively. The results emphasized the advantages of highly-organized, nanostructured, and cationic particles to achieve hybrid combinations of antimicrobials with broad spectrum activity at considerably reduced DODAB and Gr concentrations.

Synthesis and characterization of sulfonate polystyrene-lignosulfonate-alumina (SPS-LS-Al{sub 2}O{sub 3}) polyblends as electrolyte membranes for fuel cell

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gonggo, Siang Tandi, E-mail: standigonggo@yahoo.com

2015-09-30

The new type of electrolyte membrane materials has been prepared by blend sulfonated polystyrene (SPS), lignosulfonate (LS), and alumina (SPS-LS-Al{sub 2}O{sub 3}) by casting polymer solution. The resulting polymer electrolyte membranes were then characterized by functional groups analysis, mechanical properties, water uptake, ion exchange capacity, and proton conductivity. SPS-LS-Al{sub 2}O{sub 3} membranes with alumina composition various have been proven qualitatively by analysis of functional groups. Increasing the Al{sub 2}O{sub 3} ratio resulted in higher ion exchange capacity (IEC), mechanical strength and proton conductivity, but water uptake decreased. The SPS-LS-Al{sub 2}O{sub 3} blend showed higher proton conductivity than Nafion 117.

Gold surface plasmon crystal structure based-on polystyrene template for biosensor application.

PubMed

Cheng, Min-Zhuo; Zhang, Jing; Bao, Dequan; Huang, Xiwei

2018-05-21

In this communication, we assembled ordered polystyrene (PS) microsphere array as a template with the drop-coating method, and the oxygen plasma was used to etch the template to adjust the spacing between the PS microspheres. Nano-triangular gold array and silver nano-pyramid array were obtained by ion beam sputtering to deposit precious metal gold and silver. We observed the surface morphology of Au and Au/Ag composite films by scanning electron microscope and characterized the films by X-ray diffraction and ultraviolet/visible light spectrophotometer. The results show that the etching time of oxygen plasma has an obvious effect in adjusting the spacing between PSs and has a significant effect on the morphology of Au structure. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Improved perovskite morphology and crystallinity using porous PbI2 layers for efficient planar heterojunction solar cells

NASA Astrophysics Data System (ADS)

Jia, Xianyu; Hu, Ziyang; Xu, Jie; Huang, Like; Zhang, Jing; Zhang, Jianjun; Zhu, Yuejin

2017-12-01

We demonstrate the flexible and facile use of porous PbI2 layers to fabricate high quality perovskite films with a dense surface and without residual PbI2. PbI2 precursor solutions by adding polystyrene pore-forming agents are first spin-coated to fabricate the wet film. A porous PbI2 layer is formed by washing off polystyrene using organic solvents. The porous PbI2 layer not only serves as a channel for transporting the CH3NH3I solution but also offers extremely enlarged contact areas, facilitating interfacial reaction with CH3NH3I. Shiny smooth perovskite films with excellent electronic quality and solar cells with an efficiency up to 17% are obtained.

Computer Simulation of the Forces Acting on a Submerged Polystyrene Probe as it Approaches the Succinonitrile Melt-Solid Interface

NASA Technical Reports Server (NTRS)

Bune, Andris V.; Kaukler, William; Whitaker, Ann (Technical Monitor)

2001-01-01

A Modeling approach to simulate both mesoscale and microscopic forces acting in a typical AFM experiment is presented. A mesoscale level interaction between the cantilever tip and the sample surface is primarily described by the balance of attractive Van der Waals and repulsive forces. Ultimately, the goal is to measure the forces between a particle and the crystal-melt interface. Two modes of AFM operation are considered in this paper - a stationary and a "tapping" one. The continuous mechanics approach to model tip-surface interaction is presented. At microscopic levels, tip contamination and details of tip-surface interaction are modeled using a molecular dynamics approach for the case of polystyrene - succinonitrile contact. Integration of the mesoscale model with a molecular dynamic model is discussed.

Pyrolysis of virgin and waste polypropylene and its mixtures with waste polyethylene and polystyrene.

PubMed

Kiran Ciliz, Nilgun; Ekinci, Ekrem; Snape, Colin E

2004-01-01

A comparison of waste and virgin polypropylene (PP) plastics under slow pyrolysis conditions is presented. Moreover, mixtures of waste PP with wastes of polyethylene (PE) and polystyrene (PS) were pyrolyzed under the same operating conditions. Not only the impact of waste on degradation products but also impacts of the variations in the mixing ratio were investigated. The thermogravimetric weight loss curves and their derivatives of virgin and waste PP showed differences due to the impurities which are dirt and food residues. The liquid yield distribution concerning the aliphatic, mono-aromatic and poly-aromatic compounds varies as the ratio of PP waste increases in the waste plastic mixtures. In addition to this, the alkene/alkane ratio of gas products shows variations depending on the mixing ratio of wastes.

Strong coercivity reduction and high initial permeability in NiCoP coated BaFe12O19-polystyrene bilayer composite

NASA Astrophysics Data System (ADS)

Hamad, Mahmoud A.; El-Sayed, Adly H.; Hemeda, O. M.; Tawfik, A.

2016-03-01

Soft-magnetic NiCoP coated hard-magnetic M-type ferrite BaFe12O19 (BaM)-polystyrene (PS) bilayer composite film was successfully synthesized. X-ray diffraction peaks exhibited no change in the structure of BaM after coating with PS. The NiCoP coated BaM-PS composite exhibited a wasp-waisted magnetic hysteretic loop with remarkable reduction in the coercivity, remanence and squareness with respect to BaM-PS, which is useful for the core of a magnetic switching device to control currents so large that they are unmanageable. Moreover, the initial permeability measurement exhibits initial permeability of around 100 000 and thermal stability up to 558 K, which is good for flux-amplifying components of smaller inductors.

Plasma etched surface scanning inspection recipe creation based on bidirectional reflectance distribution function and polystyrene latex spheres

NASA Astrophysics Data System (ADS)

Saldana, Tiffany; McGarvey, Steve; Ayres, Steve

2014-04-01

The continual increasing demands upon Plasma Etching systems to self-clean and continue Plasma Etching with minimal downtime allows for the examination of SiCN, SiO2 and SiN defectivity based upon Surface Scanning Inspection Systems (SSIS) wafer scan results. Historically all Surface Scanning Inspection System wafer scanning recipes have been based upon Polystyrene Spheres wafer deposition for each film stack and the subsequent creation of light scattering sizing response curves. This paper explores the feasibility of the elimination of Polystyrene Latex Sphere (PSL) and/or process particle deposition on both filmed and bare Silicon wafers prior to Surface Scanning Inspection System recipe creation. The study will explore the theoretical maximal Surface Scanning Inspection System sensitivity based on PSL recipe creation in conjunction with the maximal sensitivity derived from Bidirectional Reflectance Distribution Function (BRDF) maximal sensitivity modeling recipe creation. The surface roughness (Root Mean Square) of plasma etched wafers varies dependent upon the process film stack. Decrease of the root mean square value of the wafer sample surface equates to higher surface scanning inspection system sensitivity. Maximal sensitivity SSIS scan results from bare and filmed wafers inspected with recipes created based upon Polystyrene/Particle Deposition and recipes created based upon BRDF modeling will be overlaid against each other to determine maximal sensitivity and capture rate for each type of recipe that was created with differing recipe creation modes. A statistically valid sample of defects from each Surface Scanning Inspection system recipe creation mode and each bare wafer/filmed substrate will be reviewed post SSIS System processing on a Defect Review Scanning Electron Microscope (DRSEM). Native defects, Polystyrene Latex Spheres will be collected from each statistically valid defect bin category/size. The data collected from the DRSEM will be utilized to determine the maximum sensitivity capture rate for each recipe creation mode. Emphasis will be placed upon the sizing accuracy of PSL versus BRDF modeling results based upon automated DRSEM defect sizing. An examination the scattering response for both Mie and Rayleigh will be explored in relationship to the reported sizing variance of the SSIS to make a determination of the absolute sizing accuracy of the recipes there were generated based upon BRDF modeling. This paper explores both the commercial and technical considerations of the elimination of PSL deposition as a precursor to SSIS recipe creation. Successful integration of BRDF modeling into the technical aspect of SSIS recipe creation process has the potential to dramatically reduce the recipe creation timeline and vetting period. Integration of BRDF modeling has the potential to greatly reduce the overhead operation costs for High Volume Manufacturing sites by eliminating the associated costs of third party PSL deposition.

Cationic polystyrene nanospheres induce autophagic cell death through the induction of endoplasmic reticulum stress

NASA Astrophysics Data System (ADS)

Chiu, Hui-Wen; Xia, Tian; Lee, Yu-Hsuan; Chen, Chun-Wan; Tsai, Jui-Chen; Wang, Ying-Jan

2014-12-01

Nanoparticles (NPs) have been used to produce a wide range of products that have applications in imaging and drug delivery in medicine. Due to their chemical stability, well-controlled sizes and surface charges, polystyrene (PS) NPs have been developed as biosensors and drug delivery carriers. However, the possible adverse biological effects and underlying mechanisms are still unclear. Recently, autophagy has been implicated in the regulation of cell death. In this study, we evaluated a library of PS NPs with different surface charges. We found that NH2-labeled polystyrene (NH2-PS) nanospheres were highly toxic with enhanced uptake in macrophage (RAW 264.7) and lung epithelial (BEAS-2B) cells. Furthermore, NH2-PS could induce autophagic cell death. NH2-PS increased autophagic flux due to reactive oxygen species (ROS) generation and endoplasmic reticulum (ER) stress caused by misfolded protein aggregation. The inhibition of ER stress decreased cytotoxicity and autophagy in the NH2-PS-treated cells. In addition, the Akt/mTOR and AMPK signaling pathways were involved in the regulation of NH2-PS-triggered autophagic cell death. These results suggest an important role of autophagy in cationic NP-induced cell death and provide mechanistic insights into the inhibition of the toxicity and safe material design.Nanoparticles (NPs) have been used to produce a wide range of products that have applications in imaging and drug delivery in medicine. Due to their chemical stability, well-controlled sizes and surface charges, polystyrene (PS) NPs have been developed as biosensors and drug delivery carriers. However, the possible adverse biological effects and underlying mechanisms are still unclear. Recently, autophagy has been implicated in the regulation of cell death. In this study, we evaluated a library of PS NPs with different surface charges. We found that NH2-labeled polystyrene (NH2-PS) nanospheres were highly toxic with enhanced uptake in macrophage (RAW 264.7) and lung epithelial (BEAS-2B) cells. Furthermore, NH2-PS could induce autophagic cell death. NH2-PS increased autophagic flux due to reactive oxygen species (ROS) generation and endoplasmic reticulum (ER) stress caused by misfolded protein aggregation. The inhibition of ER stress decreased cytotoxicity and autophagy in the NH2-PS-treated cells. In addition, the Akt/mTOR and AMPK signaling pathways were involved in the regulation of NH2-PS-triggered autophagic cell death. These results suggest an important role of autophagy in cationic NP-induced cell death and provide mechanistic insights into the inhibition of the toxicity and safe material design. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr05509h

21 CFR 177.2415 - Poly(aryletherketone) resins.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 12,000, as determined by gel permeation chromatography in comparison with polystyrene standards, and... milligrams per square inch of food contact surface: Distilled water, 50 percent (by volume) ethanol in...

21 CFR 177.2415 - Poly(aryletherketone) resins.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 12,000, as determined by gel permeation chromatography in comparison with polystyrene standards, and... milligrams per square inch of food contact surface: Distilled water, 50 percent (by volume) ethanol in...

21 CFR 177.2415 - Poly(aryletherketone) resins.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 12,000, as determined by gel permeation chromatography in comparison with polystyrene standards, and... milligrams per square inch of food contact surface: Distilled water, 50 percent (by volume) ethanol in...

21 CFR 177.2415 - Poly(aryletherketone) resins.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 12,000, as determined by gel permeation chromatography in comparison with polystyrene standards, and... milligrams per square inch of food contact surface: Distilled water, 50 percent (by volume) ethanol in...

46 CFR 160.010-1 - Incorporation by reference.

Code of Federal Regulations, 2014 CFR

2014-10-01

... Specification, Plastic Material, Cellular Polyurethane, Foam-In-Place, Rigid (2 and 4 Pounds per Cubic Foot....mil/quicksearch/. (1) MIL-P-19644C, Military Specification, Plastic Molding Material (Polystyrene Foam...

46 CFR 160.010-1 - Incorporation by reference.

Code of Federal Regulations, 2013 CFR

2013-10-01

... Specification, Plastic Material, Cellular Polyurethane, Foam-In-Place, Rigid (2 and 4 Pounds per Cubic Foot....mil/quicksearch/. (1) MIL-P-19644C, Military Specification, Plastic Molding Material (Polystyrene Foam...

Diclofenac removal in urine using strong-base anion exchange polymer resins.

PubMed

Landry, Kelly A; Boyer, Treavor H

2013-11-01

One of the major sources of pharmaceuticals in the environment is wastewater effluent of which human urine contributes the majority of pharmaceuticals. Urine source separation has the potential to isolate pharmaceuticals at a higher concentration for efficient removal as well as produce a nutrient byproduct. This research investigated the efficacy of using strong-base anion exchange polymer resins to remove the widely detected and abundant pharmaceutical, diclofenac, from synthetic human urine under fresh and ureolyzed conditions. The majority of experiments were conducted using a strong-base, macroporous, polystyrene resin (Purolite A520E). Ion-exchange followed a two-step removal rate with rapid removal in 1 h and equilibrium removal in 24 h. Diclofenac removal was >90% at a resin dose of 8 mL/L in both fresh and ureolyzed urine. Sorption of diclofenac onto A520E resin was concurrent with desorption of an equivalent amount of chloride, which indicates the ion-exchange mechanism is occurring. The presence of competing ions such as phosphate and citrate did not significantly impact diclofenac removal. Comparisons of three polystyrene resins (A520E, Dowex 22, Dowex Marathon 11) as well as one polyacrylic resin (IRA958) were conducted to determine the major interactions between anion exchange resin and diclofenac. The results showed that polystyrene resins provide the highest level of diclofenac removal due to electrostatic interactions between quaternary ammonium functional groups of resin and carboxylic acid of diclofenac and non-electrostatic interactions between resin matrix and benzene rings of diclofenac. Diclofenac was effectively desorbed from A520E resin using a regeneration solution that contained 4.5% (m/m) NaCl in an equal-volume mixture of methanol and water. The greater regeneration efficiency of the NaCl/methanol-water mixture over the aqueous NaCl solution supports the importance of non-electrostatic interactions between resin matrix and benzene rings of diclofenac. Experiments with ketoprofen, in addition to diclofenac, suggest that polystyrene anion exchange resins can be used to selectively remove other acidic pharmaceuticals from urine. Copyright © 2013 Elsevier Ltd. All rights reserved.

Adsorption of Poly(ethylene oxide)-Poly(lactide) Copolymers. Effects of Composition and Degradation.

PubMed

Muller, Dries; Carlsson, Fredrik; Malmsten, Martin

2001-04-01

The effect of chemical degradation of two diblock copolymers of poly(ethylene oxide) (E) and poly(lactide) (L), E(39)L(5) and E(39)L(20), on their adsorption at silica and methylated silica was investigated with in situ ellipsometry. Steric stablization of polystyrene dispersions was investigated in relation to degradation. Hydrolysis of the poly(lactide) block of the copolymers was followed at different temperatures and pH by using HPLC to measure the occurrence of lactic acid in solution. The block copolymers were quite stable in pH-unadjusted solution at low temperature, whereas degradation was facilitated by increasing temperature or lowering of the pH. Lower degradation rates of E(39)L(20) where observed at low temperature in comparison with those of E(39)L(5), whereas the degradation rates of the copolymers were quantitatively similar at high temperature. The adsorption of the copolymers at methylated silica substrates decreased with increasing degree of degradation due to the reduction in the ability of hydrophobic block to anchor the copolymer layer at the surface. At silica the adsorption initially increased with increasing degradation, particularly for E(39)L(20) due to deposition of aggregates onto the surface. After extensive degradation the adsorption of the copolymers at both silica and methylated silica resembled that of the corresponding poly(ethylene oxide) homopolymer. Overall, it was found that the eventual reduction in adsorption occurred at a lower degree of degradation for E(39)L(5) than for E(39)L(20). Mean-field calculations showed a reduced anchoring for the block copolymers with decreasing poly(lactide) block length at hydrophobic surfaces. In accordance with this finding, it was observed that polystyrene dispersions were stabilized by E(39)L(20) or E(39)L(5) in a way that depended on both the lactide block length and the degree of degradation. Upon degradation of the hydrophobic block, stabilization of the polystyrene dispersions was maintained initially, but eventually degradation resulted in destabilization. The average residual copolymer concentration required for stabilization of the polystyrene dispersions was much higher than the corresponding concentration of intact copolymer required for stabilization. Copyright 2001 Academic Press.

Thermomechanical properties of polymer nanocomposites: Exploring a unified relationship with planar polymer films

NASA Astrophysics Data System (ADS)

Bansal, Amitabh

The thermal and mechanical response of polymers, which provide limitations to their practical use, are greatly improved by the addition of a small fraction of an inorganic nanofiller. However, the resulting changes in polymer properties are poorly understood, primarily due to the non-uniform spatial distribution of nanoparticles. This research explores the properties of polystyrene filed with silica nanoparticles and illustrates for the first time that the thermodynamic properties of "polymer nanocomposites" are quantitatively equivalent to the well-understood case of planar polymer films with a uniform thickness. These ideas are quantified by drawing a direct analogy between thin film thickness and an appropriate average ligament thickness measured using electron microscopy. The change in polymer glass transition temperatures with decreasing ligament thickness were found to be quantitatively equivalent to the corresponding thin film data. In combination with viscoelastic properties of the nanocomposites that are in quantitative agreement with data from thin films, these conclusions provide a facile means of understanding and predicting the thermomechanical properties and, potentially, the engineering properties of practically relevant polymer nanocomposites. Grafting of high molecular weight polystyrene onto the silica nanoparticles greatly improves the dispersion quality of nanofillers and also provides a means to tailor the thermo-mechanical properties in nanocomposites. It is concluded that the grafted polystyrene is akin to polymer brushes on flat surfaces. The mobility and stiffness of these grafted chains are expected to be low as compared to the free polymer. In this context a mechanism for the increase in glass transition is proposed: (1) the stiff grafted chains will tend to decrease mobility and thus increase glass transition, (2) the extent of interdigitation of the grafted polystyrene into the matrix will determine the extent to which the nanocomposite properties are effected, and (3) these effects leading to slower dynamics compete with confinement effects due to the proximity of silica nanoparticles. It is shown that the well understood behavior of polymers next to flat interfaces can be used effectively to predict nanocomposite behavior. More exploration in this direction will lead to considerable scientific and technological development.

Ashley Gaulding | NREL

Science.gov Websites

inverse opal photonic crystals for CO2 reduction. Her Ph.D. work at the University of Pennsylvania (under , A.M.; Sharp, I.D.; et al., "Fabrication and optical characterization of polystyrene opal

Let Them Eat Faux Cake

ERIC Educational Resources Information Center

Peace, Suze

2012-01-01

In this article, students create a "faux" cake sculpture. It is a three-dimensional artwork made of paper, colored with markers, and decorated with old marker caps and polystyrene packing peanuts for icing swirls.

Phenolic cutter for machining foam insulation

NASA Technical Reports Server (NTRS)

Blair, T. A.; Miller, A. C.; Price, B. W.; Stiles, W. S.

1970-01-01

Pre-pregged fiber glass is an efficient abrasive for machining polystyrene and polyurethane foams. It bonds easily to any cutter base made of aluminum, steel, or phenolic, is inexpensive, and is readily available.

Improved flight-simulator viewing lens

NASA Technical Reports Server (NTRS)

Kahlbaum, W. M.

1979-01-01

Triplet lens system uses two acrylic plastic double convex lenses and one polystyrene plastic single convex lens to reduce chromatic distortion and lateral aberation, especially at large field angles within in-line systems of flight simulators.

STUDY OF REUSABLE PHOTOSENSITIVE ELECTRON RECORDING MEDIA

DTIC Science & Technology

a low molecular weight polystyrene resin (Dow Ps-2) is most suitable. The first photodielectrically deformed picture of a course bar pattern is reported using CdSe:Cu powder dispersed in carnauba wax . (Author)

Fermilab Today

Science.gov Websites

other packaging or food containers. Polystyrene consumes more than 25 percent of landfill space. It is prepared pure samples of 163Ho and 163Dy and directly measured their mass difference with high accuracy

Cup-Shaped Superparamagnetic Hemispheres for Size-Selective Cell Filtration

PubMed Central

Kim, Hyonchol; Terazono, Hideyuki; Takei, Hiroyuki; Yasuda, Kenji

2014-01-01

We propose a new method of size separation of cells exploiting precisely size-controlled hemispherical superparamagnetic microparticles. A three-layered structure of a 2-nm nickel layer inserted between 15-nm silicon dioxide layers was formed on polystyrene cast spheres by vapor deposition. The polystyrene was then removed by burning and the hemispherical superparamagnetic microparticles, “magcups”, were obtained. The standard target cells (CCRF-CEM, 12 ± 2 μm) were mixed with a set of different sizes of the fabricated magcups, and we confirmed that the cells were captured in the magcups having cavities larger than 15 μm in diameter, and then gathered by magnetic force. The collected cells were grown in a culture medium without any damage. The results suggest that this method is quick, simple and non-invasive size separation of target cells. PMID:25219418

Dielectrophoretic immobilisation of nanoparticles as isolated singles in regular arrays

NASA Astrophysics Data System (ADS)

Knigge, Xenia; Wenger, Christian; Bier, Frank F.; Hölzel, Ralph

2018-02-01

We demonstrate the immobilisation of polystyrene nanoparticles on vertical nano-electrodes by means of dielectrophoresis. The electrodes have diameters of 500 nm or 50 nm, respectively, and are arranged in arrays of several thousand electrodes, allowing many thousands of experiments in parallel. At a frequency of 15 kHz, which is found favourable for polystyrene, several occupation patterns are observed, and both temporary and permanent immobilisation is achieved. In addition, a histogram method is applied, which allows to determine the number of particles occupying the electrodes. These results are validated with scanning electron microscopy images. Immobilising exactly one particle at each electrode tip is achieved for electrode tip diameters with half the particle size. Extension of this system down to the level of single molecules is envisaged, which will avoid ensemble averaging at still statistically large sample sizes.

Self-Assembled Polystyrene Beads for Templated Covalent Functionalization of Graphitic Substrates Using Diazonium Chemistry.

PubMed

Van Gorp, Hans; Walke, Peter; Bragança, Ana M; Greenwood, John; Ivasenko, Oleksandr; Hirsch, Brandon E; De Feyter, Steven

2018-04-11

A network of self-assembled polystyrene beads was employed as a lithographic mask during covalent functionalization reactions on graphitic surfaces to create nanocorrals for confined molecular self-assembly studies. The beads were initially assembled into hexagonal arrays at the air-liquid interface and then transferred to the substrate surface. Subsequent electrochemical grafting reactions involving aryl diazonium molecules created covalently bound molecular units that were localized in the void space between the nanospheres. Removal of the bead template exposed hexagonally arranged circular nanocorrals separated by regions of chemisorbed molecules. Small molecule self-assembly was then investigated inside the resultant nanocorrals using scanning tunneling microscopy to highlight localized confinement effects. Overall, this work illustrates the utility of self-assembly principles to transcend length scale gaps in the development of hierarchically patterned molecular materials.

Dual Effect of Amino Modified Polystyrene Nanoparticles on Amyloid β Protein Fibrillation

PubMed Central

2010-01-01

The fibrillation kinetics of the amyloid β peptide is analyzed in presence of cationic polystyrene nanoparticles of different size. The results highlight the importance of the ratio between the peptide and particle concentration. Depending on the specific ratio, the kinetic effects vary from acceleration of the fibrillation process by reducing the lag phase at low particle surface area in solution to inhibition of the fibrillation process at high particle surface area. The kinetic behavior can be explained if we assume a balance between two different pathways: first fibrillation of free monomer in solution and second nucleation and fibrillation promoted at the particle surface. The overall rate of fibrillation will depend on the interplay between these two pathways, and the predominance of one mechanism over the other will be determined by the relative equilibrium and rate constants. PMID:22778827

Immobilization of Polyoxometalates on Tailored Polymeric Surfaces

PubMed Central

Aguado-Ureta, Saioa; Rodríguez-Hernández, Juan; del Campo, Adolfo; Perez-Álvarez, Leyre

2018-01-01

Herein we describe the preparation of hybrid polymer–inorganic interfaces by the immobilization of polyoxometalate nanoclusters on functionalized polymer surfaces. The polymeric surfaces were made of polystyrene-b-poly(acrylic acid)/polystyrene (PS-b-PAA/PS) blends by spin coating on a silicon wafer. The functionalization of the polymer film was obtained by interfacial migration of the amphiphilic block copolymer toward the interface upon water vapor annealing. The carboxylic acid functional groups contained in the PAA block were then employed to anchor the [LnIII(α-SiW11O39)]5− polyoxometalates (Ln: Ce, Er). This purpose was achieved by immersing the films in aqueous solutions of the in situ-formed inorganic nanoclusters. X-ray photoelectron and confocal Raman spectroscopies, together with atomic force microscopy, confirmed the immobilization of the inorganic species at the interface. PMID:29498656

Interaction between amphiphilic ionic liquid 1-butyl-3-methylimidazolium octyl sulfate and anionic polymer of sodium polystyrene sulfonate in aqueous medium

NASA Astrophysics Data System (ADS)

Barhoumi, Z.; Saini, M.; Amdouni, N.; Pal, A.

2016-09-01

The micellization of an aqueous solution of the surface active ionic liquid (SAIL), 1-butyl-3-methylimidazolium octylsufate (C4mim)(C8OSO3) and its interaction with an anionic polymer sodium polystyrene sulfonate, (NaPSS) were studied using conductimetry, tensiometry and fluorimetry. Surface tension profile shows a more dramatic increase in the value of surface tension of aqueous (C4mim)(C8OSO3) before the critical micelle concentration (cmc) of IL. The critical micelle concentration (cmc) value of this surfactant was found out from conductance measurements. The thermodynamic parameters, i.e., Gibb's free energy, enthalpy, and entropy of micellization of the IL in aqueous solution have been calculated. Behavior of fluorescence probe confirms the binding interactions between SAIL and the polyelectrolyte.

Self-Cleaning Anticondensing Glass via Supersonic Spraying of Silver Nanowires, Silica, and Polystyrene Nanoparticles.

PubMed

Lee, Jong-Gun; An, Seongpil; Kim, Tae-Gun; Kim, Min-Woo; Jo, Hong-Seok; Swihart, Mark T; Yarin, Alexander L; Yoon, Sam S

2017-10-11

We have sequentially deposited layers of silver nanowires (AgNWs), silicon dioxide (SiO 2 ) nanoparticles, and polystyrene (PS) nanoparticles on uncoated glass by a rapid low-cost supersonic spraying method to create antifrosting, anticondensation, and self-cleaning glass. The conductive silver nanowire network embedded in the coating allows electrical heating of the glass surface. Supersonic spraying is a single-step coating technique that does not require vacuum. The fabricated multifunctional glass was characterized by X-ray diffraction analysis (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), ultraviolet-visible spectroscopy, and transmission electron microscopy (TEM). The thermal insulation and antifrosting performance were demonstrated using infrared thermal imaging. The reliability of the electrical heating function was tested through extensive cycling. This transparent multifunctional coating holds great promise for use in various smart window designs.

Large scale ZnTe nanostructures on polymer micro patterns via capillary force photolithography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Florence, S. Sasi, E-mail: sshanmugaraj@jazanu.edu.sa; Can, N.; Adam, H.

2016-06-10

A novel approach to prepare micro patterns ZnTe nanostructures on Si (100) substrate using thermal evaporation is proposed by capillary Force Lithography (CFL) technique on a self-assembled sacrificial Polystyrene mask. Polystyrene thin films on Si substrates are used to fabricate surface micro-relief patterns. ZnTe nanoparticles have been deposited by thermal evaporation method. The deposited ZnTe nanoparticles properties were assessed by Atomic Force Microscope (AFM), Scanning Electron Microscope (SEM). SEM studies indicated that the particles are uniform in size and shape, well dispersed and spherical in shape. This study reports the micro-arrays of ZnTe nanoparticles on a self-assembled sacrificial PS maskmore » using a capillary flow photolithography process which showed excellent, morphological properties which can be used in photovoltaic devices for anti-reflection applications.« less

Colorimetric monitoring of solid-phase aldehydes using 2,4-dinitrophenylhydrazine.

PubMed

Shannon, Simon K; Barany, George

2004-01-01

A simple and rapid method to achieve colorimetric monitoring of resin-bound aldehydes, based on ambient temperature reaction with 2,4-dinitrophenylhydrazine (DNPH) in the presence of dilute acid, has been developed as an adjunct to solid-phase organic synthesis and combinatorial chemistry. By this test, the presence of aldehydes is indicated by a red to dark-orange appearance, within a minute. Alternatively, resins that are free of aldehydes or in which aldehyde functions have reacted completely retain their original color. The DNPH test was demonstrated for poly(ethylene glycol)-polystyrene (PEG-PS), aminomethyl polystyrene (AMP), cross-linked ethoxylate acrylate resin (CLEAR), and acryloylated O,O'-bis(2-aminopropyl)poly(ethylene glycol) (PEGA) supports and gave results visible to the naked eye at levels as low as 18 micromol of aldehyde per gram of resin.

Size Dependent Mechanical Properties of Monolayer Densely Arranged Polystyrene Nanospheres.

PubMed

Huang, Peng; Zhang, Lijing; Yan, Qingfeng; Guo, Dan; Xie, Guoxin

2016-12-13

In contrast to macroscopic materials, the mechanical properties of polymer nanospheres show fascinating scientific and application values. However, the experimental measurements of individual nanospheres and quantitative analysis of theoretical mechanisms remain less well performed and understood. We provide a highly efficient and accurate method with monolayer densely arranged honeycomb polystyrene (PS) nanospheres for the quantitatively mechanical characterization of individual nanospheres on the basis of atomic force microscopy (AFM) nanoindentation. The efficiency is improved by 1-2 orders, and the accuracy is also enhanced almost by half-order. The elastic modulus measured in the experiments increases with decreasing radius to the smallest nanospheres (25-35 nm in radius). A core-shell model is introduced to predict the size dependent elasticity of PS nanospheres, and the theoretical prediction agrees reasonably well with the experimental results and also shows a peak modulus value.

Catalytic pyrolysis of black-liquor lignin by co-feeding with different plastics in a fluidized bed reactor.

PubMed

Zhang, Huiyan; Xiao, Rui; Nie, Jianlong; Jin, Baosheng; Shao, Shanshan; Xiao, Guomin

2015-09-01

Catalytic co-pyrolysis of black-liquor lignin and waste plastics (polyethylene, PE; polypropylene PP; polystyrene, PS) was conducted in a fluidized bed. The effects of temperature, plastic to lignin ratio, catalyst and plastic types on product distributions were studied. Both aromatic and olefin yields increased with increasing PE proportion. Petrochemical yield of co-pyrolysis of PE and lignin was LOSA-1 > spent FCC > Gamma-Al2O3 > sand. The petrochemical yield with LOSA-1 is 43.9% which is more than two times of that without catalyst. The feedstock for co-pyrolysis with lignin is polystyrene > polyethylene > polypropylene. Catalytic co-pyrolysis of black-liquor lignin with PS produced the maximum aromatic yield (55.3%), while co-pyrolysis with PE produced the maximum olefin yield (13%). Copyright © 2015 Elsevier Ltd. All rights reserved.

Photonic band gap in (Pb,La)(Zr,Ti)O3 inverse opals

NASA Astrophysics Data System (ADS)

Li, Bo; Zhou, Ji; Hao, Lifeng; Hu, Wei; Zong, Ruilong; Cai, Minmin; Fu, Min; Gui, Zhilun; Li, Longtu; Li, Qi

2003-05-01

(Pb,La)(Zr,Ti)O3 (PLZT) inverse opal photonic crystals were synthesized by a process of self-assembly in combination with a sol-gel technique. In this process, PLZT precursors were infiltrated into the interstices of the opal template assembled by monodisperse submicron polystyrene spheres, and then gelled in a humid environment. Polystyrene template was removed by calcining the specimen at a final temperature of 700 °C accompanied with the crystallization of perovskite phase in PLZT inverse opal network. Scanning electron microscope images show that the inverse opals possess a fcc structure with a lattice constant of 250 nm. A wide photonic band gap in the visible range is observed from transmission spectra of the sample. Such PLZT inverse opals as photonic crystals should be of importance in device applications.

Direct measurement of optical trapping force gradient on polystyrene microspheres using a carbon nanotube mechanical resonator.

PubMed

Yasuda, Masaaki; Takei, Kuniharu; Arie, Takayuki; Akita, Seiji

2017-06-06

Optical tweezers based on optical radiation pressure are widely used to manipulate nanoscale to microscale particles. This study demonstrates direct measurement of the optical force gradient distribution acting on a polystyrene (PS) microsphere using a carbon nanotube (CNT) mechanical resonator, where a PS microsphere with 3 μm diameter is welded at the CNT tip using laser heating. With the CNT mechanical resonator with PS microsphere, we measured the distribution of optical force gradient with resolution near the thermal noise limit of 0.02 pN/μm in vacuum, in which condition enables us to high accuracy measurement using the CNT mechanical resonator because of reduced mechanical damping from surrounding fluid. The obtained force gradient and the force gradient distribution agree well with theoretical values calculated using Lorenz-Mie theory.

Biocidal action of ozone-treated polystyrene surfaces on vegetative and sporulated bacteria

NASA Astrophysics Data System (ADS)

Mahfoudh, Ahlem; Barbeau, Jean; Moisan, Michel; Leduc, Annie; Séguin, Jacynthe

2010-03-01

Surfaces of materials can be modified to ensure specific interaction features with microorganisms. The current work discloses biocidal properties of polystyrene (PS) Petri-dish surfaces that have been exposed to a dry gaseous-ozone flow. Such treated PS surfaces are able to inactivate various species of vegetative and sporulated bacteria on a relatively short contact time. Denaturation of proteins seems likely based on a significant loss of enzymatic activity of the lysozyme protein. Characterization of these surfaces by atomic-force microscopy (AFM), Fourier-transform infra-red (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS) reveals specific structural and chemical modifications as compared to untreated PS. Persistence of the biocidal properties of these treated surfaces is observed. This ozone-induced process is technically simple to achieve and does not require active precursors as in grafting.

Hydrophilic/hydrophobic surface modification impact on colloid lithography: Schottky-like defects, dislocation, and ideal distribution

NASA Astrophysics Data System (ADS)

Burtsev, Vasilii; Marchuk, Valentina; Kugaevskiy, Artem; Guselnikova, Olga; Elashnikov, Roman; Miliutina, Elena; Postnikov, Pavel; Svorcik, Vaclav; Lyutakov, Oleksiy

2018-03-01

Nano-spheres lithography is actually considered as a powerful tool to manufacture various periodic structures with a wide potential in the field of nano- and micro-fabrication. However, during self-assembling of colloid microspheres, various defects and mismatches can appear. In this work the size and quality of single-domains of closed-packed polystyrene (PS), grown up on thin Au layers modified by hydrophilic or hydrophobic functional groups via diazonium chemistry was studied. The effects of the surface modification on the quality and single-domain size of polystyrene (PS) microspheres array were investigated and discussed. Modified surfaces were characterized using the AFM and wettability tests. PS colloidal suspension was deposited using the drop evaporation method. Resulted PS microspheres array was characterized using the SEM, AFM and confocal microscopy technique.

Low-voltage high-performance organic thin film transistors with a thermally annealed polystyrene/hafnium oxide dielectric

NASA Astrophysics Data System (ADS)

Wang, Ying; Acton, Orb; Ting, Guy; Weidner, Tobias; Ma, Hong; Castner, David G.; Jen, Alex K.-Y.

2009-12-01

Low-voltage pentacene-based organic thin film transistors (OTFTs) are demonstrated with polystyrene (PS)/hafnium oxide (HfOx) hybrid dielectrics. Thermal annealing of PS films on HfOx at 120 °C (PS-120) induces a flatter orientation of the phenyl groups (tilt angle 65°) at the surface compared to PS films without annealing (PS-RT) (tilt angle 31°). The flatter phenyl group orientation leads to better matching of surface energy between pentacene and PS. Pentacene deposited on PS-120 display higher quality thin films with larger grain sizes and higher crystallinity. Pentacene OTFTs with PS-120/HfOx hybrid dielectrics can operate at low-voltage (<3 V) with high field-effect mobilities (1 cm2/V s), high on/off current ratios (106), and low subthreshold slopes (100 mV/dec).

Styrene recovery from polystyrene by flash pyrolysis in a conical spouted bed reactor.

PubMed

Artetxe, Maite; Lopez, Gartzen; Amutio, Maider; Barbarias, Itsaso; Arregi, Aitor; Aguado, Roberto; Bilbao, Javier; Olazar, Martin

2015-11-01

Continuous pyrolysis of polystyrene has been studied in a conical spouted bed reactor with the main aim of enhancing styrene monomer recovery. Thermal degradation in a thermogravimetric analyser was conducted as a preliminary study in order to apply this information in the pyrolysis in the conical spouted bed reactor. The effects of temperature and gas flow rate in the conical spouted bed reactor on product yield and composition have been determined in the 450-600°C range by using a spouting velocity from 1.25 to 3.5 times the minimum one. Styrene yield is strongly influenced by both temperature and gas flow rate, with the maximum yield being 70.6 wt% at 500°C and a gas velocity twice the minimum one. Copyright © 2015 Elsevier Ltd. All rights reserved.

Experimental benchmark for an improved simulation of absolute soft-x-ray emission from polystyrene targets irradiated with the Nike laser.

PubMed

Weaver, J L; Busquet, M; Colombant, D G; Mostovych, A N; Feldman, U; Klapisch, M; Seely, J F; Brown, C; Holland, G

2005-02-04

Absolutely calibrated, time-resolved spectral intensity measurements of soft-x-ray emission (hnu approximately 0.1-1.0 keV) from laser-irradiated polystyrene targets are compared to radiation-hydrodynamic simulations that include our new postprocessor, Virtual Spectro. This new capability allows a unified, detailed treatment of atomic physics and radiative transfer in nonlocal thermodynamic equilibrium conditions for simple spectra from low-Z materials as well as complex spectra from high-Z materials. The excellent agreement (within a factor of approximately 1.5) demonstrates the powerful predictive capability of the codes for the complex conditions in the ablating plasma. A comparison to data with high spectral resolution (E/deltaE approximately 1000) emphasizes the importance of including radiation coupling in the quantitative simulation of emission spectra.

Polystyrene latex separations by continuous flow electrophoresis on the Space Shuttle

NASA Technical Reports Server (NTRS)

Snyder, R. S.; Rhodes, P. H.; Miller, T. Y.; Micale, F. J.; Mann, R. V.

1986-01-01

The seventh mission of the Space Shuttle carried two NASA experiments in the McDonnell Douglas Astronautics Corporation continuous flow electrophoresis system. The objectives were to test the operation of continuous flow electrophoresis in a reduced gravity environment using stable particles with established electrokinetic properties and specifically to evaluate the influence of the electrical properties of the sample constituents on the resolution of the continuous flow electrophoretic device. Polystrene latex microspheres dispersed in a solution with three times the electrical conductivity of the curtain buffer separated with a significantly larger band spread compared to the second experiment under matched conductivity conditions. It is proposed that the sample of higher electrical conductivity distorted the electric field near the sample stream so that the polystyrene latex particles migrated toward the chamber walls where electroosmosis retarded and spread the sample.

Interfacial free energy governs single polystyrene chain collapse in water and aqueous solutions.

PubMed

Li, Isaac T S; Walker, Gilbert C

2010-05-12

The hydrophobic interaction is significantly responsible for driving protein folding and self-assembly. To understand it, the thermodynamics, the role of water structure, the dewetting process surrounding hydrophobes, and related aspects have undergone extensive investigations. Here, we examine the hypothesis that polymer-solvent interfacial free energy is adequate to describe the energetics of the collapse of a hydrophobic homopolymer chain at fixed temperature, which serves as a much simplified model for studying the hydrophobic collapse of a protein. This implies that changes in polymer-solvent interfacial free energy should be directly proportional to the force to extend a collapsed polymer into a bad solvent. To test this hypothesis, we undertook single-molecule force spectroscopy on a collapsed, single, polystyrene chain in water-ethanol and water-salt mixtures where we measured the monomer solvation free energy from an ensemble average conformations. Different proportions within the binary mixture were used to create solvents with different interfacial free energies with polystyrene. In these mixed solvents, we observed a linear correlation between the interfacial free energy and the force required to extend the chain into solution, which is a direct measure of the solvation free energy per monomer on a single chain at room temperature. A simple analytical model compares favorably with the experimental results. This knowledge supports a common assumption that explicit water solvent may not be necessary for cases whose primary concerns are hydrophobic interactions and hydrophobic hydration.

Immobilization of 5-aminopyridine-2-tetrazole on cross-linked polystyrene for the preparation of a new adsorbent to remove heavy metal ions from aqueous solution.

PubMed

Zhang, Yu; Chen, Youning; Wang, Chaozhan; Wei, Yinmao

2014-07-15

Novel 5-aminopyridine-2-tetrazole-functionalized polystyrene resin (APTZ-PS) was prepared by anchoring 5-aminopyridine-2-carbonitrile onto chloromethylated polystyrene beads (CMPS) and subsequently using the cyano-tetrazole conversion reaction. The APTZ-PS resin was characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS) and specific surface area and pore size analyses. The adsorption experiments of the prepared resin for heavy metal ions were conducted by batch methods. The effects of the experimental conditions, such as pH, contact time and initial metal ion concentration on the adsorption properties of Cu(II), Pb(II) and Hg(II) were investigated. The results showed that the resin possessed perfect adsorption capacities for Cu(II), Pb(II) and Hg(II), and the selectivity was different from the commonly used iminodiacetic acid-chelating resin. The sorption kinetics of the three metal ions followed the pseudo-second-order equation. The adsorption isotherms for Cu(II) and Pb(II) could be better fitted by the Langmuir model than the Freundlich model, whereas the Freundlich model was the best for the Hg(II) ion. Even after five consecutive adsorption-desorption cycles, no obvious change in the adsorption capacity of the resin was found, which implied that the APTZ-PS resin was suitable for the efficient removal of heavy metal ions from aqueous solution. Copyright © 2014 Elsevier B.V. All rights reserved.

Protein-resistant cross-linked poly(vinyl alcohol) micropatterns via photolithography using removable polyoxometalate photocatalyst.

PubMed

Pavli, Pagona; Petrou, Panagiota S; Douvas, Antonios M; Dimotikali, Dimitra; Kakabakos, Sotirios E; Argitis, Panagiotis

2014-10-22

In the last years, there has been an increasing interest in controlling the protein adsorption properties of surfaces because this control is crucial for the design of biomaterials. On the other hand, controlled immobilization of proteins is also important for their application as solid surfaces in immunodiagnostics and biosensors. Herein we report a new protein patterning method where regions of the substrate are covered by a hydrophilic film that minimizes protein adsorption. Particularly, poly(vinyl alcohol) (PVA) cross-linked structures created by an especially developed photolithographic process are proved to prevent protein physisorption and they are used as a guide for selective protein adsorption on the uncovered areas of a protein adsorbing substrate such as polystyrene. The PVA cross-linking is induced by photo-oxidation using, as a catalyst, polyoxometalate (H3PW12O40 or α-(NH4)6P2W18O62), which is removed using a methyl alcohol/water mixed solvent as the developer. We demonstrate that the polystyrene and the cross-linked PVA exhibit dramatically different performances in terms of protein physisorption. In particular, the polystyrene areas presented up to 130 times higher protein binding capacity than the PVA ones, whereas the patterning resolution could easily reach dimensions of a few micrometers. The proposed approach can be applied on any substrate where PVA films can be coated for controlling protein adsorption onto surface areas custom defined by the user.

Study the adsorption of sulfates by high cross-linked polystyrene divinylbenzene anion-exchange resin

NASA Astrophysics Data System (ADS)

Fathy, Mahmoud; Moghny, Th. Abdel; Awadallah, Ahmed E.; El-Bellihi, Abdel-Hameed A.-A.

2017-03-01

In response to rising concerns about the effect of sulfate on water quality, human health, and agriculture, many jurisdictions around the world are imposing tighter regulations for sulfate discharge. This is driving the need for environmental compliance in industries like mining, metal processing, pulp and paper, sewage treatment, and chemical manufacturing. The sulfate removal from synthetic water by high cross-linked polystyrene divinylbenzene resin was studied at batch experiments in this study. The effect of pH, contact time, sulfates concentration, and adsorbent dose on the sulfate sequestration was investigated. The optimum conditions were studied on Saline water as a case study. The results showed that with increasing of the absorbent amount; contact time, and pH improve the efficiency of sulfate removal. The maximum sulfates uptake was obtained in pH and contact time 3.0 and 120 min, respectively. Also, with increasing initial concentration of sulfates in water, the efficiency of sulfate removal decreased. The obtained results in this study were matched with Freundlich isotherm and pseudo-second-order kinetic. The maximum adsorption capacity (Qm) and constant rate were found 0.318 (mg/g) and 0.21 (mg/g.min), respectively. This study also showed that in the optimum conditions, the sulfate removal efficiency from Saline water by 0.1 mg/L sulfates was 65.64 %. Eventually, high cross-linked polystyrene divinylbenzene resin is recommended as a suitable and low cost absorbent to sulfate removal from aqueous solutions.

Fracture Properties of Polystyrene Aggregate Concrete after Exposure to High Temperatures.

PubMed

Tang, Waiching; Cui, Hongzhi; Tahmasbi, Soheil

2016-07-28

This paper mainly reports an experimental investigation on the residual mechanical and fracture properties of polystyrene aggregate concrete (PAC) after exposure to high temperatures up to 800 degrees Celsius. The fracture properties namely, the critical stress intensity factor ( K I C S ), the critical crack tip opening displacement ( CTOD C ) for the Two-Parameter Model, and the fracture energy ( G F ) for the Fictitious Crack Model were examined using the three-point bending notched beam test, according to the RILEM recommendations. The effects of polystyrene aggregate (PA) content and temperature levels on the fracture and mechanical properties of concrete were investigated. The results showed that the mechanical properties of PAC significantly decreased with increase in temperature level and the extent of which depended on the PA content in the mixture. However, at a very high temperature of 800 °C, all samples showed 80 percent reduction in modulus of elasticity compared to room temperature, regardless of the level of PA content. Fracture properties of control concrete (C) and PAC were influenced by temperature in a similar manner. Increasing temperature from 25 °C to 500 °C caused almost 50% reduction of the fracture energy for all samples while 30% increase in fracture energy was occurred when the temperature increased from 500 °C to 800 °C. It was found that adding more PA content in the mixture lead to a more ductile behaviour of concrete.

Nanoengineered Polystyrene Surfaces with Nanopore Array Pattern Alters Cytoskeleton Organization and Enhances Induction of Neural Differentiation of Human Adipose-Derived Stem Cells.

PubMed

Jung, Ae Ryang; Kim, Richard Y; Kim, Hyung Woo; Shrestha, Kshitiz Raj; Jeon, Seung Hwan; Cha, Kyoung Je; Park, Yong Hyun; Kim, Dong Sung; Lee, Ji Youl

2015-07-01

Human adipose-derived stem cells (hADSCs) can differentiate into various cell types depending on chemical and topographical cues. One topographical cue recently noted to be successful in inducing differentiation is the nanoengineered polystyrene surface containing nanopore array-patterned substrate (NP substrate), which is designed to mimic the nanoscale topographical features of the extracellular matrix. In this study, efficacies of NP and flat substrates in inducing neural differentiation of hADSCs were examined by comparing their substrate-cell adhesion rates, filopodia growth, nuclei elongation, and expression of neural-specific markers. The polystyrene nano Petri dishes containing NP substrates were fabricated by a nano injection molding process using a nickel electroformed nano-mold insert (Diameter: 200 nm. Depth of pore: 500 nm. Center-to-center distance: 500 nm). Cytoskeleton and filopodia structures were observed by scanning electron microscopy and F-actin staining, while cell adhesion was tested by vinculin staining after 24 and 48 h of seeding. Expression of neural specific markers was examined by real-time quantitative polymerase chain reaction and immunocytochemistry. Results showed that NP substrates lead to greater substrate-cell adhesion, filopodia growth, nuclei elongation, and expression of neural specific markers compared to flat substrates. These results not only show the advantages of NP substrates, but they also suggest that further study into cell-substrate interactions may yield great benefits for biomaterial engineering.

Super-resolution study of polymer mobility fluctuations near c*.

PubMed

King, John T; Yu, Changqian; Wilson, William L; Granick, Steve

2014-09-23

Nanoscale dynamic heterogeneities in synthetic polymer solutions are detected using super-resolution optical microscopy. To this end, we map concentration fluctuations in polystyrene-toluene solutions with spatial resolution below the diffraction limit, focusing on critical fluctuations near the polymer overlap concentration, c*. Two-photon super-resolution microscopy was adapted to be applicable in an organic solvent, and a home-built STED-FCS system with stimulated emission depletion (STED) was used to perform fluorescence correlation spectroscopy (FCS). The polystyrene serving as the tracer probe (670 kg mol(-1), radius of gyration RG ≈ 35 nm, end-labeled with a bodipy derivative chromophore) was dissolved in toluene at room temperature (good solvent) and mixed with matrix polystyrene (3,840 kg mol(-1), RG ≈ 97 nm, Mw/Mn = 1.04) whose concentration was varied from dilute to more than 10c*. Whereas for dilute solutions the intensity-intensity correlation function follows a single diffusion process, it splits starting at c* to imply an additional relaxation process provided that the experimental focal area does not greatly exceed the polymer blob size. We identify the slower mode as self-diffusion and the increasingly rapid mode as correlated segment fluctuations that reflect the cooperative diffusion coefficient, Dcoop. These real-space measurements find quantitative agreement between correlation lengths inferred from dynamic measurements and those from determining the limit below which diffusion coefficients are independent of spot size. This study is considered to illustrate the potential of importing into polymer science the techniques of super-resolution imaging.

Neutronics Benchmarks for the Utilization of Mixed-Oxide Fuel: Joint U.S./ Russian Progress Report for Fiscal Year 1997, Volume 4, Part 8 - Neutron Poison Plates in Assemblies Containing Homogeneous Mixtures of Polystyrene-Moderated Plutonium and Uranium Oxides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yavuz, M.

1999-05-01

In the 1970s at the Battelle Pacific Northwest Laboratory (PNL), a series of critical experiments using a remotely operated Split-Table Machine was performed with homogeneous mixtures of (Pu-U)O{sub 2}-polystyrene fuels in the form of square compacts having different heights. The experiments determined the critical geometric configurations of MOX fuel assemblies with and without neutron poison plates. With respect to PuO{sub 2} content and moderation [H/(Pu+U)atomic] ratio (MR), two different homogeneous (Pu-U) O{sub 2}-polystyrene mixtures were considered: Mixture (1) 14.62 wt% PuO{sub 2} with 30.6 MR, and Mixture (2) 30.3 wt% PuO{sub 2} with 2.8 MR. In all mixtures, the uraniummore » was depleted to about O.151 wt% U{sup 235}. Assemblies contained copper, copper-cadmium or aluminum neutron poison plates having thicknesses up to {approximately}2.5 cm. This evaluation contains 22 experiments for Mixture 1, and 10 for Mixture 2 compacts. For Mixture 1, there are 10 configurations with copper plates, 6 with aluminum, and 5 with copper-cadmium. One experiment contained no poison plate. For Mixture 2 compacts, there are 3 configurations with copper, 3 with aluminum, and 3 with copper-cadmium poison plates. One experiment contained no poison plate.« less

Intracellular dynamics of cationic and anionic polystyrene nanoparticles without direct interaction with mitotic spindle and chromosomes.

PubMed

Liu, Yuexian; Li, Wei; Lao, Fang; Liu, Ying; Wang, Liming; Bai, Ru; Zhao, Yuliang; Chen, Chunying

2011-11-01

The fate of nanomaterials with different sizes and charges in mitotic cells is of great importance but seldom explored. Herein we investigate the intracellular fate of negatively charged carboxylated polystyrene (COOH-PS) and positively charged amino-modified polystyrene (NH(2)-PS) nanoparticles of three different diameters (50, 100 and 500 nm) on cancer HeLa cells and normal NIH 3T3 cells during the cell cycles. The results showed that all the fluorescent PS nanoparticles differing in size and/or charge did not interact with chromosome reorganization and cytoskeleton assembly during the mitotic process in live cells. They neither disturbed chromosome reorganization nor affected the cytoskeleton reassembly in both normal and cancer cells. However, NH(2)-PS at the size of 50 nm caused G1 phase delay and a decrease of cyclin (D, E) expression, respectively. Moreover, NH(2)-PS displayed higher cellular toxicity and NH(2)-PS of 50 nm disturbed the integrity of cell membranes. Both cationic and anionic PS nanoparticles had a more pronounced effect on normal NIH 3T3 cells than cancer HeLa cell. Our research provides insight into the dynamic fate, intracellular behavior, and the effects of nanoparticles on spindle and chromosomes during cell division, which will enable the optimization of design and selection of much safer nanoparticles for lower risk to human health and widely medical applications. Copyright © 2011 Elsevier Ltd. All rights reserved.

Highly Tunable Complementary Micro/Submicro-Nanopatterned Surfaces Combining Block Copolymer Self-Assembly and Colloidal Lithography.

PubMed

Chang, Tongxin; Du, Binyang; Huang, Haiying; He, Tianbai

2016-08-31

Two kinds of large-area ordered and highly tunable micro/submicro-nanopatterned surfaces in a complementary manner were successfully fabricated by elaborately combining block copolymer self-assembly and colloidal lithography. Employing a monolayer of polystyrene (PS) colloidal spheres assembled on top as etching mask, polystyrene-block-poly(2-vinylpyridine) (PS-b-P2VP) or polystyrene-block-poly(4-vinylpyridine) (PS-b-P4VP) micelle films were patterned into micro/submicro patches by plasma etching, which could be further transferred into micropatterned metal nanoarrays by subsequent metal precursor loading and a second plasma etching. On the other hand, micro/submicro-nanopatterns in a complementary manner were generated via preloading a metal precursor in initial micelle films before the assembly of PS colloidal spheres on top. Both kinds of micro/submicro-nanopatterns showed good fidelity at the micro/submicroscale and nanoscale; meanwhile, they could be flexibly tuned by the sample and processing parameters. Significantly, when the PS colloidal sphere size was reduced to 250 nm, a high-resolution submicro-nanostructured surface with 3-5 metal nanoparticles in each patch or a single-nanoparticle interconnected honeycomb network was achieved. Moreover, by applying gold (Au) nanoparticles as anchoring points, micronanopatterned Au arrays can serve as a flexible template to pattern bovine serum albumin (BSA) molecules. This facile and cost-effective approach may provide a novel platform for fabrication of micropatterned nanoarrays with high tunability and controllability, which are promising in the applications of biological and microelectronic fields.

Enterococcus hirae biofilm formation on hospital material surfaces and effect of new biocides.

PubMed

Di Lodovico, Silvia; Cataldi, Valentina; Di Campli, Emanuela; Ancarani, Elisabetta; Cellini, Luigina; Di Giulio, Mara

2017-08-02

Nowadays, the bacterial contamination in the hospital environment is of particular concern because the hospital-acquired infections (HAIs), also known as nosocomial infections, are responsible for significant morbidity and mortality. This work evaluated the capability of Enterococcus hirae to form biofilm on different surfaces and the action of two biocides on the produced biofilms. The biofilm formation of E. hirae ATCC 10541 was studied on polystyrene and stainless steel surfaces through the biomass quantification and the cell viability at 20 and 37 °C. The effect of LH IDROXI FAST and LH ENZYCLEAN SPRAY biocides on biomasses was expressed as percentage of biofilm reduction. E. hirae at 20 and 37 °C produced more biofilm on the stainless steel in respect to the polystyrene surface. The amount of viable cells was greater at 20 °C than with 37 °C on the two analyzed surfaces. Biocides revealed a good anti-biofilm activity with the most effect for LH ENZYCLEAN SPRAY on polystyrene and stainless steel at 37 °C with a maximum biofilm reduction of 85.72 and 86.37%, respectively. E. hirae is a moderate biofilm producer depending on surface material and temperature, and the analyzed biocides express a remarkable antibiofilm action. The capability of E. hirae to form biofilm can be associated with its increasing incidence in hospital-acquired infections, and the adoption of suitable disinfectants is strongly recommended.