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Sample records for a-c films prepared

  1. High conductivity a-C:N thin films prepared by electron gun evaporation

    SciTech Connect

    Rebollo-Plata, B.; Lozada-Morales, R.; Palomino-Merino, R.; Portillo-Moreno, O.; Jimenez-Sandoval, S.; Zelaya-Angel, O. . E-mail: ozelaya@fis.cinvestav.mx

    2007-08-15

    By employing electron beam evaporation, amorphous carbon nitride (a-C:N) thin films, with a low nitrogen content ({approx} 1%), were prepared on Si(110) and glass substrates at about 150 deg. C. The source was a graphite target and an ambient of N{sub 2} was introduced into the growing chamber. The source-substrate distance (SSD) was the main parameter that was intentionally varied. Electron dispersion spectroscopy measurements indicate the nitrogen concentration in the layer as {approx} 1%. The dark electrical conductivity ({sigma}) of layers was very sensitive to SSD variation, changing up to six orders of magnitude when this parameter was varied from 10.5 to 23.5 cm. A maximum value of {sigma} = 1 x 10{sup 3} {omega}{sup -1} cm{sup -1} at room temperature was obtained when the SSD was equal to 15.5 cm. We have deduced that, in accordance with the Ferrari-Robertson model (FRM), our samples are localized in the second stage of the amorphization trajectory of FRM. When the SSD increases the C atoms have more probability to collide with N{sub 2} molecules, and the content of nitrogen in the a-C film increases. The amorphization trajectory followed by the films with an SSD increase is from nanocrystalline graphite to amorphous carbon. The changes in the amorphization are due to the nitrogen content in the layers.

  2. Microstructure of a-C:H films prepared on a microtrench and analysis of ions and radicals behavior

    NASA Astrophysics Data System (ADS)

    Hirata, Yuki; Choi, Junho

    2015-08-01

    Amorphous carbon films (a-C:H) were prepared on a microtrench (4-μm pitch and 4-μm depth), and the uniformity of film thickness and microstructure of the films on the top, sidewall, and bottom surfaces of the microtrench were evaluated by scanning electron microscopy and Raman spectroscopy. The a-C:H films were prepared by bipolar-type plasma based ion implantation and deposition (bipolar PBII&D), and the negative pulse voltage, which is the main parameter dominating the film structure, was changed from -1.0 to -15 kV. Moreover, the behavior of ions and radicals was analyzed simultaneously by combining the calculation methods of Particle-In-Cell/Monte Carlo Collision (PIC-MCC) and Direct Simulation Monte Carlo (DSMC) to investigate the coating mechanism for the microtrench. The results reveal that the thickness uniformity of a-C:H films improves with decreasing negative pulse voltage due to the decreasing inertia of incoming ions from the trench mouth, although the film thickness on the sidewall tends to be much smaller than that on the top and bottom surfaces of the trench. The normalized flux and the film thickness show similar behavior, i.e., the normalized flux or thickness at the bottom surface increases at low negative pulse voltages and then saturates at a certain value, whereas at the sidewall it monotonically decreases with increasing negative voltage. The microstructure of a-C:H films on the sidewall surface is very different from that on the top and bottom surfaces. The film structure at a low negative pulse voltage shifts to more of a polymer-like carbon (PLC) structure due to the lower incident energy of ions. Although the radical flux on the sidewall increases slightly, the overall film structure is not significantly changed because this film formation at a low negative voltage is originally dominated by radicals. On the other hand, the flux of radicals is dominant on the sidewall in the case of high negative pulse voltage, resulting in a deviation

  3. Microstructure of a-C:H films prepared on a microtrench and analysis of ions and radicals behavior

    SciTech Connect

    Hirata, Yuki; Choi, Junho

    2015-08-28

    Amorphous carbon films (a-C:H) were prepared on a microtrench (4-μm pitch and 4-μm depth), and the uniformity of film thickness and microstructure of the films on the top, sidewall, and bottom surfaces of the microtrench were evaluated by scanning electron microscopy and Raman spectroscopy. The a-C:H films were prepared by bipolar-type plasma based ion implantation and deposition (bipolar PBII&D), and the negative pulse voltage, which is the main parameter dominating the film structure, was changed from −1.0 to −15 kV. Moreover, the behavior of ions and radicals was analyzed simultaneously by combining the calculation methods of Particle-In-Cell/Monte Carlo Collision (PIC-MCC) and Direct Simulation Monte Carlo (DSMC) to investigate the coating mechanism for the microtrench. The results reveal that the thickness uniformity of a-C:H films improves with decreasing negative pulse voltage due to the decreasing inertia of incoming ions from the trench mouth, although the film thickness on the sidewall tends to be much smaller than that on the top and bottom surfaces of the trench. The normalized flux and the film thickness show similar behavior, i.e., the normalized flux or thickness at the bottom surface increases at low negative pulse voltages and then saturates at a certain value, whereas at the sidewall it monotonically decreases with increasing negative voltage. The microstructure of a-C:H films on the sidewall surface is very different from that on the top and bottom surfaces. The film structure at a low negative pulse voltage shifts to more of a polymer-like carbon (PLC) structure due to the lower incident energy of ions. Although the radical flux on the sidewall increases slightly, the overall film structure is not significantly changed because this film formation at a low negative voltage is originally dominated by radicals. On the other hand, the flux of radicals is dominant on the sidewall in the case of high negative pulse voltage, resulting in a

  4. Effect of incorporation of deuterium on vacancy-type defects of a-C:H films prepared by plasma CVD

    NASA Astrophysics Data System (ADS)

    Ozeki, K.; Sekiba, D.; Uedono, A.; Hirakuri, K. K.; Masuzawa, T.

    2015-03-01

    Amorphous deuterated carbon (a-C:D) films were prepared using plasma-enhanced chemical vapor deposition (PECVD) from CH4/CD4 and CH4/D2 source gases. For CH4/CD4, the gas flow ratio of CD4/(CD4 + CH4) was varied from 0 to 100%. For CH4/D2, the additional partial gas pressure of D2 was increased from 1 to 7 Pa as the flow rate increased, and the partial gas pressure and the flow rate of CH4 were maintained at 10 Pa and 10 sccm, respectively. The concentrations of hydrogen (H) and deuterium (D) relative to carbon (C) in the films and the film densities were determined by elastic recoil detection analysis (ERDA) and Rutherford backscattering spectroscopy (RBS). Positron annihilation spectroscopy (PAS) was performed to measure the vacancy-type defect of the film. The S value obtained from PAS measurement correlates to the vacancy-type defect in the film. The film hardness was also measured using a nanoindenter. For CH4/CD4, the D concentration in the film increased when the CD4/(CH4 + CD4) gas ratio increased, whereas the concentration of H decreased. For CH4/D2, the D concentration in the film increased with increasing D2 partial pressure, whereas the concentration of H decreased. From the PAS results, the S value increased with increasing CD4/(CH4 + CD4) gas ratio for CH4/CD4, whereas the S value did not change with any D2 partial pressure for CH4/D2. The hardness and the mass density of the films decreased when the CD4/(CH4 + CD4) gas ratio increased for CH4/CD4, whereas the hardness and the density did not change with any D2 partial pressure for CH4/D2. A correlation among the S value, the film hardness and the film density was observed, and the S value, the film hardness and the film density did not correlate to the D concentration in the film. These findings suggest that information about the vacancy-type defect of the hydrogenated amorphous carbon films is crucial for evaluation of their mechanical properties and density.

  5. Effect of C2H2 flow rate on microstructure and properties of nc-Cu/a-C:H nanocomposite films prepared by filtered cathodic vaccum arc technique

    NASA Astrophysics Data System (ADS)

    Zhang, Haiqiang; Chen, Yiming; Liao, Bin; Wu, Xianying; Zhang, Huixing; Zhang, Xu

    2013-07-01

    Nc-Cu/a-C:H nanocomposite films are deposited by filtered cathodic vaccum arc (FCVA) technique using C2H2 as the precursor. The effects of C2H2 flow rate on the microstructure, composition and properties of nc-Cu/a-C:H films have been studied by Raman spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and nanoindentation test. In these films, copper nanoparticles (3.5-15 nm) are embedded in the amorphous carbon matrix, which could be confirmed by XRD analysis. Raman spectroscopy and XPS results confirm the decrease of sp3 content with the increasing copper fraction, which could be a result of more severe thermalization on carbon matrix owing to the presence of copper. The compressive stresses of these films, calculated by Stoney's equation, are found to be as low as 0.5 Gpa, declining with the increasing copper content. Nanoindentation measurements reveal that the film hardness falls monotonically as the Cu content in the films increases.

  6. Ion irradiation effects on a-C:H, a-C:N:H and a-C:F:H films

    NASA Astrophysics Data System (ADS)

    Galvão, J. R.; Luce, F. P.; Baptista, D. L.; da Costa, M. E. M. Maia; Lepienski, C. M.; Zawislak, F. C.

    2006-08-01

    Hydrogenated amorphous carbon (a-C:H) films as well as films with incorporated nitrogen (a-C:N:H) and fluorine (a-C:F:H) have been irradiated with 400 keV N+ at fluences ranging from 1014 to 3 × 1016 ions cm-2. The films were 200 nm thick deposited on Si and irradiated at RT. The loss of H, N and F as function of the irradiated fluences was monitored via nuclear reactions. The results show that: (i) the loss of H in all cases is well explained by the molecular recombination model; (ii) there is no loss of N and F as function of fluence for the a-C:N:H and a-C:F:H films. The evolution of the hardness and Young modulus for the three films reach the same values of ≈12 and 130 GPa, respectively, at maximum fluence. The intrinsic stress data show a change from a compressive stress to a relaxed structure after irradiations. The Raman data confirm the microstructural evolution of the samples into a structure containing a large number of disordered sp2-C clusters.

  7. Optical properties of a-C:H thin films modified by Ti and Ag

    NASA Astrophysics Data System (ADS)

    Prikhodko, Oleg Yu.; Mikhailova, Svetlana L.; Mukhametkarimov, Ershan C.; Maksimova, Suyumbika Ya.; Manabaev, Nurlan K.; Dauthan, Kuanysh

    2016-09-01

    Structure and optical properties of amorphous diamond-like carbon (a-C: H) thin films modified with Ag, Ti and Ag + Ti metal impurities are studied. The films were prepared by ion-plasma magnetron sputtering of combined polycrystalline graphite and metal target in the mixture of Ar and CH4 gases. AFM, SEM and TEM methods show that a-C:H films are heterogeneous, nanostructured and characterized by the presence of silver nanoclusters on the surface sized 60 nm and both Ti and Ag nanoclusters with a mean size (2 ÷ 3) nm in the bulk of films. It was found that in a- C:H films as well as in a-C:H films plasma resonance absorption due to excitation of surface plasmons in silver nanoclusters in the visible region of spectrum takes place. Intensity of the resonance absorption in the a- C:H films increases with increase in concentration of silver. The results are important for produce of nanomaterials with nonlinear optical properties based on the amorphous diamond-like carbon films containing metal nanoclusters.

  8. Mechanical properties of Al/a-C nanocomposite thin films synthesized using a plasma focus device

    NASA Astrophysics Data System (ADS)

    A. Umar, Z.; S. Rawat, R.; R., Ahmad; K. Kumar, A.; Y., Wang; Hussain, T.; Z., Chen; Shen, L.; Zhang, Z.

    2014-02-01

    The Al/a-C nanocomposite thin films are synthesized on Si substrates using a dense plasma focus device with aluminum fitted anode and operating with CH4/Ar admixture. X-ray diffractometer results confirm the formation of metallic crystalline Al phases using different numbers of focus shots. Raman analyses show the formation of D and G peaks for all thin film samples, confirming the presence of a-C in the nanocomposite thin films. The formation of Al/a-C nanocomposite thin films is further confirmed using X-ray photoelectron spectroscopy analysis. The scanning electron microscope results show that the deposited thin films consist of nanoparticles and their agglomerates. The sizes of th agglomerates increase with increasing numbers of focus deposition shots. The nanoindentation results show the variations in hardness and elastic modulus values of nanocomposite thin film with increasing the number of focus shots. Maximum values of hardness and elastic modulus of the composite thin film prepared using 20 focus shots are found to be about 10.7 GPa and 189.2 GPa, respectively.

  9. Texture control and growth mechanism of WSe2 film prepared by rapid selenization of W film

    NASA Astrophysics Data System (ADS)

    Li, Hongchao; Gao, Di; Li, Kun; Pang, Mengde; Xie, Senlin; Liu, Rutie; Zou, Jianpeng

    2017-02-01

    The tungsten diselenide (WSe2) films with different orientation present unique properties suitable for specific applications, such as WSe2 with a C-axis⊥substrate for optoelectronics and WSe2 with a C-axis // substrate for electrocatalysts. Orientation control of WSe2 is essential for realizing the practical applications. In this letter, a WSe2 film has been prepared via rapid selenization of a magnetron-sputtered tungsten (W) film. The influence of the magnetron-sputtered W film on WSe2 film growth was studied systematically. Scanning electron microscopy, X-ray diffractometry and high-resolution transmission electron microscopy were used to evaluate the morphology, microstructure and phase composition of the W and WSe2 films. The substrate temperature has a significant effect on the W film phase composition, but little effect on the WSe2 film orientation. The WSe2 orientation can be controlled by changing the W film microstructure. A dense W film that is deposited at low pressure is conducive to the formation of WSe2 with a C-axis⊥substrate, whereas a porous W film deposited at high pressure favors the formation of WSe2 with a C-axis // substrate. A growth model for the WSe2 film with different texture has been proposed based on the experimental results. The direction of selenium (Se) vapor diffusion differs at the top and side surfaces. This is a key factor for the preparation of anisotropic WSe2 films. Highly oriented WSe2 films with a C-axis⊥substrate grow from the dense W film deposited at low pressure because Se vapor can only diffuse into the W film from the top surface where it is converted into selenide. Highly oriented WSe2 with a C-axis // substrate can be achieved for the porous W film that is deposited at high pressure because the nanopores provide a fast transmission tunnel for Se vapor diffusion. These findings will contribute to the controlled fabrication of WSe2 film and provide a theoretical basis for its application.

  10. Preparation of a semiconductor thin film

    DOEpatents

    Pehnt, Martin; Schulz, Douglas L.; Curtis, Calvin J.; Ginley, David S.

    1998-01-01

    A process for the preparation of a semiconductor film. The process comprises depositing nanoparticles of a semiconductor material onto a substrate whose surface temperature during nanoparticle deposition thereon is sufficient to cause substantially simultaneous fusion of the nanoparticles to thereby coalesce with each other and effectuate film growth.

  11. Preparation of a semiconductor thin film

    DOEpatents

    Pehnt, M.; Schulz, D.L.; Curtis, C.J.; Ginley, D.S.

    1998-01-27

    A process is disclosed for the preparation of a semiconductor film. The process comprises depositing nanoparticles of a semiconductor material onto a substrate whose surface temperature during nanoparticle deposition thereon is sufficient to cause substantially simultaneous fusion of the nanoparticles to thereby coalesce with each other and effectuate film growth.

  12. Properties of a-C:H:Si thin films deposited by middle-frequency magnetron sputtering

    NASA Astrophysics Data System (ADS)

    Jiang, Jinlong; Wang, Yubao; Du, Jinfang; Yang, Hua; Hao, Junying

    2016-08-01

    The silicon doped hydrogenated amorphous carbon (a-C:H:Si) films were prepared on silicon substrates by middle-frequency magnetron sputtering silicon target in an argon and methane gas mixture atmosphere. The deposition rate, chemical composition, structure, surface properties, stress, hardness and tribological properties in the ambient air of the films were systemically investigated using X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), atomic force microscopy (AFM), nanoindentation and tribological tester. The results show that doped silicon content in the films is controlled in the wide range from 39.7 at.% to 0.2 at.% by various methane gas flow rate, and methane flow rate affects not only the silicon content but also its chemical bonding structure in the films due to the transformation of sputtering modes. Meanwhile, the sp3 carbon component in the films linearly increases with increasing of methane flow rate. The film deposited at moderate methane flow rate of 40-60 sccm exhibits the very smooth surface (RMS roughness 0.4 nm), low stress (0.42 GPa), high hardness (21.1 GPa), as well as low friction coefficient (0.038) and wear rate (1.6 × 10-7 mm3/Nm). The superior tribological performance of the films could be attributed to the formation and integral covering of the transfer materials on the sliding surface and their high hardness.

  13. Physical properties of a-C:N films produced by ion beam assisted deposition

    SciTech Connect

    Rossi, F. ); Andre, B. ); van Veen, A.; Mijnarends, P.E.; Schut, H.; Labohm, F. ); Dunlop, H. ); Delplancke, M.P. ); Hubbard, K. )

    1994-09-01

    Carbon films with up to 32 at. % of nitrogen have been prepared with ion beam assisted magnetron, using a N[sup +][sub 2]/N[sup +] beam at energies between 50 and 300 eV. The composition and density of the films vary strongly with the deposition parameters. EELS, SXS, XPS, and IR studies show that these a-C:N films are mostly graphitic and have up to 20% [ital sp][sup 3] bonding. Nitrogen is mostly combined with carbon in nitrile (C[equivalent to]N) and imine (C=N) groups. RBS and NDP show that density goes through a maximum as the average damage energy per incoming ion increases. Positron annihilation spectroscopy shows that the void concentration in the films goes through a minimum with average damage energy. These results are consistent with a densification induced by the collisions at low average damage energy values and induced graphitization at higher damage energy values. These results are similar to what is observed for Ar ion assisted deposition of a-C films. The mechanical properties of these films have been studied with a nanoindenter, and it was found that the hardness and Young's modulus go through a maximum as the average damage energy is increased. The maximum of mechanical properties corresponds to the minimum in the void concentration in the film. Tribological studies of the a-C:N show that the friction coefficient obtained against diamond under dynamic loading decreases strongly as the nitrogen composition increases, this effect being more pronounced at low loads.

  14. Surface-Wave Plasma Deposition of a-C:H Films for Field Emission

    NASA Astrophysics Data System (ADS)

    Sano, Toru; Nagatsu, Masaaki; Takada, Noriharu; Toyoda, Hirotaka; Sugai, Hideo; Guang, W. X.; Hirao, Takashi; Toyoda, Naoki

    2000-10-01

    Recently crystalline diamond or diamondlike carbon (DLC) thin films prepared by the plasma enhanced CVD techniques have been widely studied as a new material of electron emitter for the next generation large-area field emission display. Among them, DLC films grown at low temperature are more attractive from an aspect of industrial manufacturing. In this study, we have carried out the deposition of hydrogenated amorphous carbon(a-C:H) films using a high density, low pressure surface-wave plasma (SWP). The SWP was produced in a 40cm-diameter vacuum chamber by introducing 2.45 GHz microwave through a quartz window via slot antennas. The a-C:H films were deposited on a silicon substrate immersed in He/CH4 plasma, under discharge conditions of 700 W microwave power and 200 mTorr total pressure. Excellent field emission characteristics were obtained: the threshold electric field defined at an emission current density of 1 μA/cm^2 was obtained to be 4 V/μm. Other film characteristics measured with the XPS and FT-IR are also presented. This work was supported by a Grant-in-Aid for Science Research from the Ministry of Education, Science, Sports and Culture in Japan.

  15. Preparation and characterization of gradient polymer films

    SciTech Connect

    Smith, S.C.

    1987-01-01

    Gradient polymers are multicomponent polymers whose chemical constitution varies with depth in the sample. Although these polymers may possess unique mechanical, optical, and barrier properties they remain relatively unexplored. This work is a study of the preparation of gradient polymers by sequential exposure of films to a diffusing monomer followed by electron beam irradiation. Initial experiments involved immersion of poly(vinyl chloride) (PVC) films in styrene or n-butyl methacrylate (BMA) for various time periods followed by irradiation with 1 or 10 megarads of accelerated electrons. A significant amount of poly(n-butyl methacrylate) (PBMA) formed in PVC/BMA systems, but little polystyrene could be found in the PVC/styrene films. A second set of experiments involved immersion of PVC and polyethylene (PE) films in BMA for 20, 40, 60, and 720 minutes followed by irradiation with 10 megarads of electrons. These films were then characterized using optical microscopy, quantitative transmission Fourier transform infrared spectroscopy (FTIR), and a depth profiling procedure based on quantitative attenuated total reflection (ATR) FTIR. It was concluded that the mechanism of PBMA formation in the polyethylene films was a result of events immediately following irradiation. Atmospheric oxygen diffusing into irradiated films trapped free radicals at the film surfaces. This was followed by storage in an evacuated desiccator where unintentional exposure to BMA vapor took place. This BMA reacted with free radicals that remained within the film cores, polymerizing to PBMA.

  16. Ambient pressure process for preparing aerogel thin films reliquified sols useful in preparing aerogel thin films

    SciTech Connect

    Brinker, C.J.; Prakash, S.S.

    1999-09-07

    A method for preparing aerogel thin films by an ambient-pressure, continuous process is disclosed. The method of this invention obviates the use of an autoclave and is amenable to the formation of thin films by operations such as dip coating. The method is less energy intensive and less dangerous than conventional supercritical aerogel processing techniques.

  17. Ambient pressure process for preparing aerogel thin films reliquified sols useful in preparing aerogel thin films

    DOEpatents

    Brinker, Charles Jeffrey; Prakash, Sai Sivasankaran

    1999-01-01

    A method for preparing aerogel thin films by an ambient-pressure, continuous process. The method of this invention obviates the use of an autoclave and is amenable to the formation of thin films by operations such as dip coating. The method is less energy intensive and less dangerous than conventional supercritical aerogel processing techniques.

  18. Preparation and applications of magnetostrictive thin films

    NASA Astrophysics Data System (ADS)

    Quandt, E.; Geriach, B.; Seemann, K.

    1994-11-01

    Amorphous magnetostrictive films of the binary compound Sm(x)Fe(1-x) as well as of the ternary compound (Tb(y)Dy(1-y)(x)Fe(1-x) were prepared by rf or dc magnetron sputtering using either a multitarget arrangement with pure element targets or cash composite-type targets. The magnetostrictive properties of (Tb0.3Dy0.7)(0.4)Fe0.6 and Sm0.Fe0.6 films were investigated in relation to their preparation conditions. Depending upon these conditions (especially upon the deposition rate, the bias voltage, and the Ar sputtering pressure) amorphous films with a giant magnetostriction of about 250 ppm (-220 ppm) at 0.1 T and 400 ppm (-300 ppm) at 0.5 T for the TbDyFe (SmFe) and an in-plane magnetic easy axis could be prepared. In view of applications in microsystem technologies (e.g., pumps, valves, positioning elements) these films have been tested in a simple cantilever arrangement and the predicted deflection of a magnetostrictive actuated membrane has been calculated.

  19. Preparation and application of agar/alginate/collagen ternary blend functional food packaging films.

    PubMed

    Wang, Long-Feng; Rhim, Jong-Whan

    2015-09-01

    Ternary blend agar/alginate/collagen (A/A/C) hydrogel films with silver nanoparticles (AgNPs) and grapefruit seed extract (GSE) were prepared. Their performance properties, transparency, tensile strength (TS), water vapor permeability (WVP), water contact angle (CA), water swelling ratio (SR), water solubility (WS), and antimicrobial activity were determined. The A/A/C film was highly transparent, and both AgNPs and GSE incorporated blend films (A/A/C(AgNPs) and A/A/C(GSE)) exhibited UV-screening effect, especially, the A/A/C(GSE) film had high UV-screening effect without sacrificing the transmittance. In addition, the A/A/C blend films formed efficient hydrogel film with the water holding capacity of 23.6 times of their weight. Both A/A/C(AgNPs) and A/A/C(GSE) composite films exhibited strong antimicrobial activity against both Gram-positive (Listeria monocytogenes) and Gram-negative (Escherichia coli) food-borne pathogenic bacteria. The test results of fresh potatoes packaging revealed that all the A/A/C ternary blend films prevented forming of condensed water on the packaged film surface, both A/A/C(AgNPs) and A/A/C(GSE) composite films prevented greening of potatoes during storage. The results indicate that the ternary blend hydrogel films incorporated with AgNPs or GSE can be used not only as antifogging packaging films for highly respiring fresh agriculture produce, but also as an active food packaging system utilizing their strong antimicrobial activity.

  20. Auger electron spectroscopy, secondary ion mass spectroscopy and optical characterization of a-C-H and BN films

    NASA Technical Reports Server (NTRS)

    Pouch, J. J.; Alterovitz, S. A.; Warner, J. D.

    1986-01-01

    The amorphous dielectrics a-C:H and BN were deposited on III-V semiconductors. Optical band gaps as high as 3 eV were measured for a-C:H generated by C4H10 plasmas; a comparison was made with bad gaps obtained from films prepared by CH4 glow discharges. The ion beam deposited BN films exhibited amorphous behavior with band gaps on the order of 5 eV. Film compositions were studied by Auger electron spectroscopy (AES), x-ray photoelectron spectroscopy (XPS) and secondary ion mass spectrometry (SIMS). The optical properties were characterized by ellipsometry, UV/VIS absorption, and IR reflection and transmission. Etching rates of a-C:H subjected to O2 dicharges were determined.

  1. Thin film preparation of semiconducting iron pyrite

    NASA Astrophysics Data System (ADS)

    Smestad, Greg P.; Ennaoui, Ahmed; Fiechter, Sebastian; Hofmann, Wolfgang; Tributsch, Helmut; Kautek, Wolfgang

    1990-08-01

    Pyrite (Fe52) has been investigated as a promising new absorber material for thin film solar cell applications because of its high optical absorption coefficient of 1OL cm1, and its bandgap of 0.9 to 1.0 eV. Thin layers have been prepared by Metal Organic Chemical Vapor Deposition, MOCVD, Chemical Spray Pyrolysis, CSP, Chemical Vapor Transport, CVT, and Sulfurization of Iron Oxide films, 510. It is postulated that for the material FeS2, if x is not zero, a high point defect concentration results from replacing 2 dipoles by single S atoms. This causes the observed photovoltages and solar conversion efficiencies to be lower than expected. Using the Fe-O-S ternary phase diagram and the related activity plots, a thermodynamic understanding is formulated for the resulting composition of each of these types of films. It is found that by operating in the oxide portion of the phase diagram, the resulting oxidation state favors pyrite formation over FeS. By proper orientation of the grains relative to the film surface, and by control of pinholes and stoichiometry, an efficient thin film photovolatic solar cell material could be achieved.

  2. Thick film traps with an irregular film. Preparation and evaluation.

    PubMed

    Kloskowski, Adam; Pettersson, Johan; Roeraade, Johan

    2004-05-07

    A new method for preparation of sorbent-based ultra-thick film traps for concentration of trace volatile components from gaseous matrices is described. The procedure is based on blowing a prepolymer (polydimethylsiloxane) through a capillary tube, forming an irregular film of stationary phase. Subsequently, the prepolymer is immobilized in a few seconds by heating to 200 degrees C. Evaluation of the performance of the new traps showed that the loss of efficiency, compared to regular smooth film traps is only on the order of 20-30%. In terms of breakthrough volume, this loss in performance is rather insignificant. The technology is extremely simple and allows a rapid and cheap production of a large number of ultra-thick film traps, even in non-specialized laboratories. The method can be applied to any type of cross-linkable stationary phase, thereby expanding the scope of sorbent-based trapping and preconcentration concept. Many applications are anticipated in trace and ultra-trace analysis in a wide range of fields, such as environmental chemistry, polymers, food and process analysis.

  3. Elastic properties of a-C :N:H films

    NASA Astrophysics Data System (ADS)

    Wang, Chengbing; Yang, Shengrong; Li, Hongxuan; Zhang, Junyan

    2007-01-01

    Dual dc-rf plasma system has been used to deposit hydrogenated carbon nitride (CNx:H) films that exhibit high elastic recovery (75%). Transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectra and Raman spectra were subsequently used to study the microstructure and bonding of the resultant films. The structure of the films from TEM is seen to consist of many particles embedded in an amorphous carbon matrix, and the films can be described as graphitelike or onionlike with interplanar distances of ≈1.15, 1.95, and 3.5Å, as obtained from selected area electron diffraction (SAED). FTIR shows that nitrogen promotes the formation of sp2 C C/CN aromatic rings in the films. Raman spectra shows two apparent peaks at about 700 and 1200cm-1 in addition to the G and D peaks. Only by adding two extra peaks at approximately 1230 and 1470cm-1 can we deconvolute the Raman spectra of CNx:H in the region of 1000-2000cm-1. Combining TEM and SAED, we attribute the three peaks at about 700, 1200, and 1470cm-1 to fullerene or onion structure. However, the elastic recovery is relatively lower than elastic hydrogenated free carbon nitride films. We think that this is due to the fact that hydrogen is mainly incorporated to sp3 carbon and suppresses cross-linking three-dimensional (3D) network growth.

  4. Preparation and Evaluation of Stomatitis Film Using Xyloglucan Containing Loperamide.

    PubMed

    Kawano, Yayoi; Sasatsu, Masanaho; Mizutani, Ayako; Hirose, Kaoru; Hanawa, Takehisa; Onishi, Hiraku

    2016-06-01

    Stomatitis induced by radiation therapy or cancer chemotherapy is a factor in sleep disorders and/or eating disorders, markedly decreasing patient quality of life. In recent years, disintegrating oral films that are easy to handle have been developed; therefore, we focused on the formulation of these films. We prepared an adhesive film for the oral cavity using xyloglucan (Xylo), which is a water-soluble macromolecule. We used loperamide, which has been reported to relieve pain caused by stomatitis effectively, as a model drug in this study. Films were prepared from Xylo solutions (3% (w/w)) and hypromellose (HPMC) solutions (1% (w/w)). Xylo and HPMC solutions were mixed at ratios of 1 : 1, 2 : 1, or 3 : 1 for each film, and films 2×2 cm weighing 3 g were prepared and dried at 37°C for 24 h. Physicochemical properties such as strength, adhesiveness, disintegration behavior, and dissolution of loperamide from films were evaluated. Films prepared from Xylo solution alone had sufficient strength and mucosal adhesion. On the other hand, films prepared from a mixture of Xylo and HPMC were inferior to those made from Xylo, but showed sufficient strength and mucosal adhesion and were flexible and easy to handle. The films prepared in this study are useful as adhesion films in the oral cavity.

  5. Erosion of a-C:H films under interaction with nitrous oxide afterglow discharge

    NASA Astrophysics Data System (ADS)

    Zalavutdinov, R. Kh.; Gorodetsky, A. E.; Bukhovets, V. L.; Zakharov, A. P.; Mazul, I. V.

    2009-06-01

    Hydrocarbon film removal using chemically active oxygen formed in a direct current glow discharge with a hollow cathode in nitrous oxide was investigated. In the afterglow region sufficiently fast removal of a-C:H films about 500 nm thick during about 8 h was achieved at N 2O pressure of 12 Pa and 370 K. The erosion rate in the afterglow region was directly proportional to the initial pressure and increased two orders of magnitude at temperature rising from 300 to 500 K. The products of a-C:H film plasmolysis were CO, CO 2, H 2O, and H 2. After removal of a-C:H films previously deposited on stainless steel, molybdenum or tungsten 3-30 nm thick oxide films were formed on the substrates. Reactions of oxygen ion neutralization and atomic oxygen recombination suppressed further oxidation of the materials.

  6. Characterization of nanocomposite a-C:H/Ag thin films synthesized by a hybrid deposition process

    NASA Astrophysics Data System (ADS)

    Venkatesh, M.; Taktak, S.; Meletis, E. I.

    2015-08-01

    Silver containing amorphous carbon films were deposited on Si wafer using a hybrid deposition process combining d.c. magnetron sputtering and PECVD. The concentration of Ag in the films was varied from 1.3 to 8.3 at % by changing d.c. magnetron current of Ag target. The influence of incorporated Ag in the a-C:H on the atomic bond structure of the films were investigated by XPS, FTIR, Raman, and HRTEM methods of analysis. The XPS, FTIR, and Raman studies demonstrated that as the silver concentration increased in the a-C:H, sp2 bonding content increased and a-C:H films changed to more graphitic structure. The high resolution TEM cross sectional studies revealed that crystalline Ag particles formed with a size in the range of 2-4 nm throughout an amorphous a-C:H matrix.

  7. WC/a-C nanocomposite thin films: Optical and electrical properties

    SciTech Connect

    Abad, M. D.; Sanchez-Lopez, J. C.; Cusnir, N.; Sanjines, R.

    2009-02-01

    WC/amorphous carbon (a-C) thin films were deposited by dual magnetron sputtering from individual WC and graphite targets. The influence of film composition and microstructure on the optical and electrical properties was investigated. As evidenced by x-ray photoelectron spectroscopy and grazing angle x-ray diffraction measurements, the WC/a-C films are composite materials made of hexagonal W{sub 2}C and/or cubic {beta}-WC{sub 1-X} nanocrystallites embedded in (a-C) matrix. The optical properties were studied by spectroscopic ellipsometry and the electrical resistivity was measured by the van der Pauw method between 20 and 300 K. Both the optical and the electrical properties of the WC/a-C films are correlated with the chemical composition and microstructure evolution caused by a-C addition. The optical properties of W{sub 2}C/a-C and {beta}-WC{sub 1-x}/a-C films with a-C content {<=}10 at. % are explained by modeling their dielectric functions by a set of Drude-Lorentz oscillators. Further increase in a-C content leads only to the formation of {beta}-WC{sub 1-x}/a-C nanocomposite structures and their optical properties progressively evolve to those of a-C single phase. The electrical resistivity as a function of the temperature of all the films exhibits a negative temperature coefficient of resistivity. Theoretical fitting using the grain-boundary scattering model shows that the transport properties are mainly limited by the grain size and electron mean free path parameters.

  8. Electron cyclotron resonance deposition of a-Si:H and a-C:H films

    NASA Technical Reports Server (NTRS)

    Shing, Y. H.; Yang, C. L.; Allevato, C. E.; Pool, F. S.

    1989-01-01

    Amorphous silicon (a-Si:H) and amorphous carbon (a-C:H) films have been deposited by electron cyclotron resonance (ECR) microwave plasma enhanced CVD. A high deposition rate of 25 A/sec and a light-to-dark conductivity ratio of 500,000 for a-Si:H films have been achieved by the ECR process using a pure silane plasma. ECR microwave plasmas have been analyzed by in situ optical emission spectroscopy (OES) and have shown a strong H-asterisk emission at 434 nm indicating higher chemical reactivity than RF plasmas. The linear correlation between the film deposition rate and the SiH-asterisk emission intensity of ECR silane plasma suggests that SiH-asterisk species are related to the neutral radicals which are responsible for the a-Si:H film deposition. Hard and soft a-C:H films have been deposited by ECR with and without RF bias power, respectively. The RF bias to the substrate is found to play a critical role in determining the film structure and the carbon bonding configuration of ECR deposited a-C:H films. Raman spectra of these films indicate that ECR deposition conditions can be optimized to produce diamond films.

  9. Preparation of thin polymer films for infrared reaction rate studies

    NASA Technical Reports Server (NTRS)

    Garrard, G. G.; Houston, D. W.

    1970-01-01

    Procedure for preparing thin films for infrared spectrophotometric analysis involves pressing of a neat mixture of reactants between nonreactive thin polymer films with noninterfering absorption bands. Pressing is done under a pressure that gives desirable thickness. Following this process, the film sandwich is cut to accommodate the laboratory instrument.

  10. Study of bagasse/tapioca starch film preparation and characterization

    NASA Astrophysics Data System (ADS)

    Chen, Yanyang; Wei, Xiaoyi; Chang, Gang; Fu, Tiaokun; Cui, Lihong; Li, Jihua

    2017-06-01

    Bagasse/tapioca starch films (BT) were prepared with various contents of bagasse (10, 20, 30, 40 and 50 wt% based on tapioca starch), and the effect of bagasse concentration was studied by the performance of the BT films. Then, the BT films characteristics were analyzed using the instruments about ultraviolet spectrophotometer (US), SEM, TGA and XRD. The dispersion of the bagasse became better with bagasse concentration increasing, the intermolecular hydrogen bonding became stronger while the transparency values of the films decreased.

  11. Silk fibroin/pullulan blend films: Preparation and characterization

    SciTech Connect

    Shivananda, C. S.; Rao, B. Lakshmeesha; Madhukumar, R.; Asha, S.; Sarojini, B. K.; Somashekhar, R.; Sangappa, Y.

    2016-05-23

    In this work silk fibroin/pullulan blend films have been prepared by solution casting method. The blend films were examined for structural, and thermal properties using X-ray diffraction (XRD), thermogravimatric (TGA) and differential scanning calorimetry (DSC) analysis. The XRD results indicate that with the introduction of pullulan, the interaction between SF and pullulan in the blend films induced the conformation transition of SF films and amorphous phase increases with increasing pullulan ratio. The thermal properties of the blend films were improved significantly in the blend films.

  12. Reactions of ultrathin hard amorphous carbon (a-C) films under microbeam laser processing

    SciTech Connect

    Zhang Lihong; Gong Hao; Li Yuanqing; Wang Jianping

    2004-11-01

    The decomposition mechanism of hard a-C films under irradiation using a microbeam laser (514.5 nm) was studied. The films were magnetron sputtered at different pressures to achieve different degrees of sp{sup 3}/sp{sup 2} bonding ratio. Under laser irradiation, they showed graphitization and decomposition. The graphitization saturated at early exposure of {approx}4 min, while the decomposition progressed exponentially with the exposure time, following a first-order reaction mechanism. The decomposition of a-C films under laser irradiation can be modeled using a two-step process with the establishment of a quasi steady-state intermediate. The relative energy barrier and rate constant for film decomposition were calculated. With increasing sp{sup 3}/sp{sup 2} bonding ratio, the films showed increasing resistance against the irradiation-induced changes. This is shown by the decreasing rate constant and increasing energy barrier during the decomposition.

  13. Origin of superlubricity in a-C:H:Si films: a relation to film bonding structure and environmental molecular characteristic.

    PubMed

    Chen, Xinchun; Kato, Takahisa; Nosaka, Masataka

    2014-08-27

    Superlubricity of Si-containing hydrogenated amorphous carbon (a-C:H:Si) films has been systematically investigated in relation to the film bonding structure and the environmental atmosphere. Structural diversity induced by hydrogen incorporation (i.e., 17.3-36.7 at. % H), namely sp(2)-bonded a-C, diamond-like or polymer-like, and tribointeractions activated by the participation of environmental gaseous molecules mainly determine the frictional behaviors of a-C:H:Si films. A suitable control of hydrogen content in the film (i.e., the inherent hydrogen coverage) is obligate to obtain durable superlubricity in a distinct gaseous atmosphere such as dry N2, reactive H2 or humid air. Rapid buildup of running-in-induced antifriction tribolayers at the contact interface, which is more feasible in self-mated sliding, is crucial for achieving a superlubric state. Superior tribological performances have been observed for the polymer-like a-C:H:Si (31.9 at. % H) film, as this hydrogen-rich sample can exhibit superlow friction in various atmospheres including dry inert N2 (μ ∼ 0.001), Ar (μ ∼ 0.012), reactive H2 (μ ∼ 0.003) and humid air (μ ∼ 0.004), and can maintain ultralow friction in corrosive O2 (μ ∼ 0.084). Hydrogen is highlighted for its decisive role in obtaining superlow friction. The occurrence of superlubricity in a-C:H:Si films is generally attributed to a synergistic effect of phase transformation, surface passivation and shear localization, for instance, the near-frictionless state occurred in dry N2. The contribution of each mechanism to the friction reduction depends on the specific intrafilm and interfilm interactions along with the atmospheric effects. These antifriction a-C:H:Si films are promising for industrial applications as lubricants.

  14. Preparation and characterization of multilayered hydroxyapatite/silk fibroin film.

    PubMed

    Kino, Rikako; Ikoma, Toshiyuki; Yunoki, Shunji; Nagai, Nobuhiro; Tanaka, Junzo; Asakura, Tetsuo; Munekata, Masanobu

    2007-06-01

    We prepared multilayered films consisting of silk fibroin (SF) and hydroxyapatite (HAp) by alternating lamination using untreated SF and HAp-deposited SF films. Untreated SF films were prepared from a regenerated SF solution by air drying. HAp-deposited SF films were prepared by soaking methanol-treated SF films containing >5 wt% CaCl2 in a simulated body fluid with the ion concentration 1.5-fold higher than that of the standard one. The multilayered HAp/SF films had HAp layers with approximate thicknesses of 3-5 microm and SF layers with thicknesses of 40-70 microm. The bonding strength between the SF and HAp layers was significantly affected by temperature and compression time under the lamination method. The optimal conditions for achieving the maximum T-peel strength and beta-sheet contents were determined to be 130 degrees C for 4 min. The Young's modulus of the multilayered films (133.4 MPa) was higher than that of the films consisting of SF alone (92.5 MPa) under swollen conditions. The biocompatibility of the HAp-deposited SF films was analyzed by culturing of osteoblasts (MC3T3-E1) on a film. The results indicate that HAp-deposited SF films and SF films show similar degrees of cell adhesion and alkaline phosphatase activities.

  15. Process for the preparation of metal-containing nanostructured films

    NASA Technical Reports Server (NTRS)

    Lu, Yunfeng (Inventor); Wang, Donghai (Inventor)

    2006-01-01

    Metal-containing nanostructured films are prepared by electrodepositing a metal-containing composition within the pores of a mesoporous silica template to form a metal-containing silica nanocomposite. The nanocomposite is annealed to strengthen the deposited metal-containing composition. The silica is then removed from the nanocomposite, e.g., by dissolving the silica in an etching solution to provide a self-supporting metal-containing nanostructured film. The nanostructured films have a nanowire or nanomesh architecture depending on the pore structure of the mesoporous silica template used to prepare the films.

  16. a-C:H/a-C:H(N) thin film deposition using 2.45 GHz expanding surface wave sustained plasmas

    NASA Astrophysics Data System (ADS)

    Hong, Suk-Ho; Douai, David; Berndt, Johannes; Winter, Jörg

    2005-08-01

    Thin film properties such as homogeneity (radial profiles), optical constants, carbon density in the film, and the surface structures are strongly dependent on deposition conditions. We have investigated a-C:H/a-C:H(N) thin film deposition by expanding Ar-CH4 and Ar/N2-CH4 surface wave sustained plasmas at a frequency of 2.45 GHz. The influence of the plasma parameters such as pressure, input power, gas mixture rate, and an external bias voltage on the change of the film properties is systematically studied. An external bias applied to the substrate leads to more dense and harder a-C:H films, i.e. change from soft polymer-like to hard diamond-like. Rutherford backscattering and atomic force microscope surface topology confirm the densification of the films.

  17. Mechanical Properties and in Vitro and in Vivo Biocompatibility of a-C/a-C:Ti Nanomultilayer Films on Ti6Al4V Alloy as Medical Implants.

    PubMed

    Li, Lingling; Bai, Wenqi; Wang, Xiuli; Gu, Changdong; Jin, Gong; Tu, Jiangping

    2017-05-17

    Hydrogen-free a-C/a-C:Ti nanomultilayer films are deposited on medical Ti6Al4V alloy using a closed field unbalanced magnetron sputtering under graded bias voltage. The mechanical and tribological properties of the nanomultilayer films are performed on the nanoindentor, Rockwell and scratch tests, and ball-on-disk tribometer. The biological properties are evaluated by cell cytotoxicity, genotoxicity, subchronic systemic toxicity and implant. The hard a-C/a-C:Ti nanomultilayer films on medical alloy exhibit high adhesion strength and excellent tribological properties in both ambient air and Hank's solution. Biocompatibility results reveal the film no cytotoxity, no genotoxicity, no subchronic systemic toxicity and no contraindications in implant systems. Because of excellent mechanical properties and biosafety, the carbon-based films on medical alloy unveils a prospective application in medical implants.

  18. Electrical properties of a-C:Mo films produced by dual-cathode filtered cathodic arc plasma deposition

    SciTech Connect

    Sansongsiri, Sakon; Anders, Andre; Yodsombat, Banchob

    2008-01-20

    Molybdenum-containing amorphous carbon (a-C:Mo) thin films were prepared using a dual-cathode filtered cathodic arc plasma source with a molybdenum and a carbon (graphite) cathode. The Mo content in the films was controlled by varying the deposition pulse ratio of Mo and C. Film sheet resistance was measured in situ at process temperature, which was close to room temperature, as well as ex situ as a function of temperature (300-515 K) in ambient air. Film resistivity and electrical activation energy were derived for different Mo and C ratios and substrate bias. Film thickness was in the range 8-28 nm. Film resistivity varied from 3.55x10-4 Omega m to 2.27x10-6 Omega m when the Mo/C pulse ratio was increased from 0.05 to 0.4, with no substrate bias applied. With carbon-selective bias, the film resistivity was in the range of 4.59x10-2 and 4.05 Omega m at a Mo/C pulse ratio of 0.05. The electrical activation energy decreased from 3.80x10-2 to 3.36x10-4 eV when the Mo/C pulse ratio was increased in the absence of bias, and from 0.19 to 0.14 eV for carbon-selective bias conditions. The resistivity of the film shifts systematically with the amounts of Mo and upon application of substrate bias voltage. The intensity ratio of the Raman D-peak and G-peak (ID/IG) correlated with the pre-exponential factor (sigma 0) which included charge carrier density and density of states.

  19. Deposition of a-C:H films on a nanotrench pattern by bipolar PBII&D

    NASA Astrophysics Data System (ADS)

    Hirata, Yuki; Nakahara, Yuya; Nagato, Keisuke; Choi, Junho

    2016-06-01

    In this study, hydrogenated amorphous carbon (a-C:H) films were deposited on a nanotrench pattern (300 nm pitch, aspect ratio: 2.0) by bipolar-type plasma based ion implantation and deposition technique (bipolar PBII&D), and the effects of bipolar pulse on the film properties were investigated. Moreover, the behaviour of ions and radicals surrounding the nanotrench was analyzed to clarify the coating mechanism and properties of the a-C:H films on the nanotrench. Further, thermal nanoimprint lithography was carried out using the nanotrench pattern coated with a-C:H films as the mold, and the mold release properties were evaluated. All nanotrench surfaces were successfully coated with the a-C:H films, but the film thickness on the top, sidewall, and bottom surfaces of the trench were not uniform. The surface roughness of the a-C:H films was found to decrease at a higher positive voltage; this happens due to the higher electron temperature around the nanotrench because of the surface migration of plasma particles arrived on the trench. The effects of the negative voltage on the behaviour of ions and radicals near the sidewall of the nanotrench are quite similar to those near the microtrench reported previously (Park et al 2014 J. Phys. D: Appl. Phys. 47 335306). However, the positive pulse voltage was also found to affect the behaviour of ions and radicals near the sidewall surface. The incident angles of ions on the sidewall surface increased with the positive pulse voltage because the energy of incoming ions on the trench decreases with increasing positive voltage. Moreover, the incident ion flux on the sidewall is affected by the positive voltage history. Further, the radical flux decreases with increasing positive voltage. It can be concluded that a higher positive voltage at a lower negative voltage condition is good to obtain better film properties and higher film thickness on the sidewall surface. Pattern transfer properties for the nanoimprint formed by

  20. Preparation of Modified Films with Protein from Grouper Fish

    PubMed Central

    Tecante, A.; Granados-Navarrete, S.; Martínez-García, C.

    2016-01-01

    A protein concentrate (PC) was obtained from Grouper fish skin and it was used to prepare films with different amounts of sorbitol and glycerol as plasticizers. The best performing films regarding resistance were then modified with various concentrations of CaCl2, CaSO4 (calcium salts), and glucono-δ-lactone (GDL) with the purpose of improving their mechanical and barrier properties. These films were characterized by determining their mechanical properties and permeability to water vapor and oxygen. Formulations with 5% (w/v) protein and 75% sorbitol and 4% (w/v) protein with a mixture of 15% glycerol and 15% sorbitol produced adequate films. Calcium salts and GDL increased the tensile fracture stress but reduced the fracture strain and decreased water vapor permeability compared with control films. The films prepared represent an attractive alternative for being used as food packaging materials. PMID:27597950

  1. Facile method to prepare a transparent superhydrophobic PET film

    NASA Astrophysics Data System (ADS)

    Wang, Jian; Chen, Hong; Wang, Xian; Yuan, Zhiqing

    2016-11-01

    A simple method to fabricate a transparent superhydrophobic coating was developed by spraying PDMS/SiO2 nanoparticles suspension on a hydrophilic PET film. This PDMS/SiO2 nanoparticles suspension was prepared by fully diluting and properly stirring. When this suspension was sprayed on the surface of PET film at a distance of about 30 cm for 2 s, a porous micro-nano-binary structure was formed, which endowed the hydrophilic PET film superhydrophobicity, while the PET film maintained transparent after spraying with a SiO2 nanoparticle layer. The as-prepared superhydrophobic PET film exhibited a high water contact angle of about 155° ± 1.9° and a low water sliding angle of about 7°. The formation mechanism of this transparent superhydrophobic coating on PET film was also discussed in detail in this paper.

  2. Preparation of patterned ultrathin polymer films.

    PubMed

    Yang, Huige; Su, Meng; Li, Kaiyong; Jiang, Lei; Song, Yanlin; Doi, Masao; Wang, Jianjun

    2014-08-12

    Though patterned ultrathin polymer films (<100 nm) are of great importance in the fields of sensors and nanoelectronic devices, the fabrication of patterned ultrathin polymer films remains a great challenge. Herein, patterned ultrathin polymer films are fabricated facilely on hydrophobic substrates with different hydrophilic outline patterns by the pinning of three-phase contact lines of polymer solution on the hydrophilic outlines. This method is universal for most of the water-soluble polymers, and poly(vinyl alcohol) (PVA) has been selected as a model polymer due to its biocompatibility and good film-forming property. The results indicate that the morphologies of ultrathin polymer films can be precisely adjusted by the size of the hydrophilic outline pattern. Specifically, patterned hydrophilic outlines with sizes of 100, 60, and 40 μm lead to the formation of concave-shaped ultrathin PVA films, whereas uniform ultrathin PVA films are formed on 20 and 10 μm patterned substrates. The controllabilities of morphologies can be interpreted through the influences of the slip length and coffee ring effect. Theoretical analysis shows that when the size of the hydrophilic outline patterns is smaller than a critical value, the coffee ring effect disappears and uniform patterned ultrathin polymer films can be formed for all polymer concentrations. These results provide an effective methodology for the fabrication of patterned ultrathin polymer films and enhance the understanding of the coffee ring effect.

  3. Preparation of Thick Magnet Films by the Aerosol Deposition Method

    NASA Astrophysics Data System (ADS)

    Sugimoto, Satoshi

    The aerosol deposition method (ADM) is effective for the preparation of thick films with high deposition rate. We applied this method to fabricate NiZn ferrite or Sm-Fe-N films, which are used for microwave absorbers or permanent magnets, respectively. In this article, the magnetic properties of Sm-Fe-N thick films fabricated by the ADM are introduced and the possibility of the ADM for the fabrication process with high deposition rate is discussed.

  4. Nanocomposite film prepared by depositing xylan on cellulose nanowhiskers matrix

    Treesearch

    Qining Sun; Anurag Mandalika; Thomas Elder; Sandeep S. Nair; Xianzhi Meng; Fang Huang; Art J. Ragauskas

    2014-01-01

    Novel bionanocomposite films have been prepared by depositing xylan onto cellulose nanowhiskers through a pH adjustment. Analysis of strength properties, water vapour transmission, transparency, surface morphology and thermal decomposition showed the enhancement of film performance. This provides a new green route to the utilization of biomass for sustainable...

  5. 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…

  6. 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…

  7. Preparation and Characterization of PZT Thin Films

    SciTech Connect

    Bose, A.; Sreemany, M.; Bhattacharyya, D. K.; Sen, Suchitra; Halder, S. K.

    2008-07-29

    In analogy with Piezoelectric Wafer Active Sensors (PWAS), Lead Zirconate Titanate (PZT) thin films also seem to be promising for Structural Health Monitoring (SHM) due to a number of reasons. Firstly, PZT thin films with well oriented domains show enhanced piezoelectric response. Secondly, PWAS requires comparatively large voltage leading to a demand for thin PZT films (<< {mu}m in thickness) for low voltage operation at {<=}10 V. This work focuses on two different aspects: (a) growing oriented PZT thin films in ferroelectric perovskite phase in the range of (80-150) nm thickness on epitaxial Si/Pt without a seed layer and (b) synthesizing perovskite phase in PZT thin films on Corning glass 1737 using a seed layer of TiO{sub x} (TiO{sub x} thickness ranging between 30 nm to 500 nm)

  8. Improved Preparation Of Solid-Electrolyte Films

    NASA Technical Reports Server (NTRS)

    Nagasubramanian, Ganesan; Attia, Alan

    1995-01-01

    Modified process ensures compatability among components. Improved chemical-blending procedure produces composite material for thin, large-area solid-electrolyte films for lithium batteries. Films have uniform compositions and dimensionally stable. Transport number of their lithium cations is high, close to unity. Batteries made with these films expected to have energy and power densities up to about 100 W h/kg and 100 W/kg, respectively. Previous version of composite material described in "Composite Solid Electrolyte for Lithium Cells" (NPO-18694).

  9. Solar cells from thin films prepared by periodic pulse electrodeposition

    NASA Astrophysics Data System (ADS)

    Morris, G. C.; Vanderveen, R. J.

    1996-02-01

    Periodic pulse electrodeposition (PPE) of CdS and CdTe polycrystalline films is reported. These films adhered more strongly to FTO than to ITO and better to either substrate than films prepared by DC methods. Solar cells of the type glass/conducting transparent oxide/nCdS/pCdTe/Au had superior properties when PPE CdS films were used. A CdCl 2 treatment of the CdS layer was an essential fabrication step for stable, efficient, larger area cells.

  10. Photon statistics, film preparation and characterization in fluorescent microthermal imaging

    SciTech Connect

    Tangyunyong, Paiboon; Barton, D.L.

    1995-08-01

    Fluorescent microthermal imaging (FMI) involves coating a sample surface with a thin inorganic-based film that, upon exposure to uv light, emits temperature-dependent fluorescence. FMI offers the ability to create thermal maps of integrated circuits with a thermal resolution theoretically limited to 1 m{degree}C and a spatial resolution diffraction-limited to 0.3 {mu}m. Even though FMI has been in use for more than a decade, many factors that can affect the thermal image quality have not been studied well. This paper presents recent results showing the limitations from photon shot noise and the improvement in signal-to-noise ratio from signal averaging. Three important factors in film preparation and characterization are presented that have a significant impact on thermal quality and sensitivity of FMI: uv bleaching, film dilution, and film curing. It is shown how proper film preparation and data collection method can dramatically improve the quality of FMI thermal images.

  11. Preparation of crystalline tungsten oxide films from organometallic precursors

    SciTech Connect

    Meda, L.; Kirss, R.U.

    1995-12-31

    Thin films of tungsten oxide, WO{sub 3}, are of interest in the preparation of electrochromic display devices. Chemical vapor deposition experiments using tetra(allyl)tungsten, W({eta}{sup 3}-C{sub 3}H{sub 5}){sub 4}, led to the deposition of dark, reflective, amorphous carbon rich tungsten/tungsten carbide films on SiO{sub 2} glass between 250 and 450{degrees}C. When {approx}0.25 {mu} thick films were annealed at 400{degrees}C under oxygen, conversion to transparent, nearly colorless, crystalline WO{sub 3} was observed. The films were characterized by x-ray diffraction, SEM and ESCA. Shorter reaction times and lower temperatures yielded dark blue, amorphous films characteristic of WO{sub 3-n} films. The smooth blue films were characterized by SEM and ESCA. While the crystalline WO{sub 3} films were found to be electrically insulating, the blue films were found to be electrically conductive. Preliminary results on the conversion of the WO{sub 3} films to tungsten sulfide and tungsten selenide films will be discussed.

  12. Preparation and characterization of oxadiazole based electron transporting thin films

    NASA Astrophysics Data System (ADS)

    Mahajan, Aman; Aulakh, Ramanpreet Kaur; Bedi, R. K.

    2012-08-01

    To study the effect of aggregation of the 2-(4-biphenylyl)-5-phenyl-1,3,4-oxadiazole (PBD) molecule in solid state, thin films of PBD have been prepared by the thermal evaporation technique onto glass and quartz substrates under different experimental conditions. These films have been studied for their structural, optical and electrical properties. AFM investigations of the films revealed that the films were smooth, dense and crack free with RMS roughness of 11-14 nm. XRD measurements indicate that films deposited on quartz are more crystalline than films deposited on glass substrate. Both absorption and reflectance spectra over the wavelength range 200-800 nm have been recorded to find optical parameters, namely, absorption, extinction coefficient, refractive index and dielectric constants. The inter-band transition energies are found to lie within the range 3.45-3.49 eV. Optical studies of the films indicate that PBD molecules preferred J-aggregation. A prominent single emission peak in the range of 370-390 nm has been observed which confirms that the fluorescent property of this molecule is not quenched in the thin film state. The electrical conductivity results for the evaporated films exhibited semiconductor behaviour within the investigated field and temperature range. The nature of the substrate is found to be a useful tool to modify the film morphology and for enhancing the charge transport within the films.

  13. Preparation of Sm doped cerium dioxide film by anodization

    NASA Astrophysics Data System (ADS)

    LIU, Xiaozhen; Yang, Junhua; Liu, Xiaozhou; Xia, Letian; Chen, Jie; Zhu, Ying

    2017-04-01

    The Sm doped cerium dioxide films were prepared with cerium foils as raw materials by anodization in Sm(NO3)3-Na2C2O4-NH3·H2O-H2O-(CH2OH)2 electrolyte. The anodic Sm doped cerium oxide film was heat treated at 550°C. The Sm doped cerium dioxide films were characterized with X-ray diffraction (XRD), energy-dispersive analyses of X-ray (EDAX), Fourier transform infrared (FTIR) techniques and scanning electron microcopy (SEM), respectively. The anodic Sm doped cerium oxide film is semi crystalline film. The heat treated anodic Sm doped cerium oxide film at 550°C has a structure of cubic fluorite. The doping of Sm is replacement doping or caulking doping. The Sm doped cerium dioxide film is porous film. The water, ethylene glycol and CO2 are adsorbed in the anodic Sm doped cerium oxide film. The adsorbing water, ethylene glycol and CO2 in the anodic Sm doped cerium oxide film are removed at 550°C. The Sm doped cerium dioxide film has strong absorption in the range of 1200 ~ 4000cm-1.

  14. Commissioning a hobby cutting device for radiochromic film preparation.

    PubMed

    Zolfaghari, Somayeh; Francis, Kirby E; Kairn, Tanya; Crowe, Scott B

    2017-03-30

    In addition to a high spatial resolution and well characterised dose response, one of the major advantages of radiochromic film as a dosimeter is that sheets of film can be cut into pieces suitable for use as calibration films, and for in vivo and phantom measurements. The cutting of film is typically done using scissors or a guillotine, and this process can be time-consuming, limited in precision, requires extensive handling and does not allow holes to be cut from the film without cutting from an existing edge. This study investigated the use of a Brother ScanNCut hobby cutting system for EBT3 film preparation. The optimal operating parameters (blade size, pressure, speed) that resulted in precise cuts with minimal delamination at cut edges were identified using test cutting patterns. These parameters were then used to cut a large film insert for a stereotactic head phantom for comparison against an insert cut with scissors. While the hobby cutting system caused a wider region of delamination at the film edge (1.8 mm) compared to scissors (1 mm), the hobby cutting system was found to be able to produce reproducible cuts more efficiently and more accurately than scissors. The use of the hobby cutting system is recommended for complex phantom inserts (containing sharp corners or holes for alignment rods) or in situations where large numbers of film pieces need to be prepared.

  15. Preparation of thin film silver fluoride electrodes from constituent elements

    NASA Technical Reports Server (NTRS)

    Odonnell, P. M.

    1972-01-01

    The feasibility of preparing thin-film metal fluoride electrodes from the elemental constituents has been demonstrated. Silver fluoride cathodes were prepared by deposition of silver on a conducting graphite substrate followed by fluorination under controlled conditions using elemental fluorine. The resulting electrodes were of high purity, and the variables such as size, shape, and thickness were easily controlled.

  16. Raman Spectroscopy of a-C:H Films Deposited Using Ar + H2 + C7H8 Plasma CVD

    NASA Astrophysics Data System (ADS)

    Dong, Xiao; Koga, Kazunori; Yamashita, Daisuke; Seo, Hyunwoong; Itagaki, Naho; Shiratani, Masaharu; Setsuhara, Yuichi; Sekine, Makoto; Hori, Masaru

    2015-09-01

    We investigated the effects of ion energy on Raman spectra of a-C:H films prepared by Ar + H2 + C7H8 plasma CVD. Raman spectra were measured with a laser Raman spectrometer (JASCO NRS-3100). Both the D-peak position and G-peak position shift toward higher wavenumbers as ion energy increases. The intensity ratio of the D-peak and G-peak, ID/IG increases with increasing the ion energy, indicating that the amount of ring-like sp2 clusters increases. The H content in a-C:H derived from photoluminescence (PL) background decreases with increasing the ion energy. The full width at half maximum of the G-peak, FWHMG related to the C-C sp3 content and H content increases with increasing the ion energy to 100 eV, whereas it decreases with increasing further the ion energy to 105 eV. The variation of FWHMG is consistent with that of mass density. There results indicate that the structure of a-C:H films transforms from polymer-like carbon to diamond-like one with increasing the ion energy above the threshold value of ~ 100 eV.

  17. Enhancement of adhesion by a transition layer: Deposition of a-C film on ultrahigh molecular weight polyethylene (UHMWPE) by magnetron sputtering

    NASA Astrophysics Data System (ADS)

    He, F. F.; Bai, W. Q.; Li, L. L.; Wang, X. L.; Xie, Y. J.; Jin, G.; Tu, J. P.

    2016-02-01

    An amorphous carbon (a-C) film is deposited on the plasma-treated UHMWPE substrate using a closed field unbalanced magnetron sputtering to improve its tribological properties. During the plasma treatment period, a transition layer is prepared by high energy ion bombardment at a bias voltage of -500 V to enhance the adhesion between the a-C film and the substrate. The mechanical and tribological properties of the a-C film were evaluated by nano-indentation and ball-on-disk tribometer. After deposition of a-C film with a thickness 900 nm, the nano-hardness of UHMWPE significantly increases from 47 MPa to 720 MPa and the wear rate decreases from 9.82 × 10-15 m3 N-1 m-1 to 4.78 × 10-15 m3 N-1 m-1 in bovine calf serum solution. The formation of the transition layer is believed to be the reason why the vertical adhesion between the a-C film and the UHMWPE substrate is enhanced.

  18. Preparation of graphene thin films for radioactive samples.

    PubMed

    Roteta, Miguel; Fernández-Martínez, Rodolfo; Mejuto, Marcos; Rucandio, Isabel

    2016-03-01

    A new method for the preparation of conductive thin films is presented. The metallization of VYNS films guarantees the electrical conductivity but it results in the breaking of a high proportion of them. Graphene, a two-dimensional nanostructure of monolayer or few layers graphite has attracted a great deal of attention because of its excellent properties such as a good chemical stability, mechanical resistance and extraordinary electronic transport properties. In this work, the possibilities of graphene have been explored as a way to produce electrical conductive thin films without an extra metallization process. The procedure starts with preparing homogenous suspensions of reduced graphene oxide (rGO) in conventional VYNS solutions. Ultra-sonication is used to ensure a good dispersibility of rGO. Graphene oxide (GO) is prepared via oxidation of graphite and subsequent exfoliation by sonication. Different chemically rGO were obtained by reaction with hydrazine sulfate, sodium borohydride, ascorbic acid and hydroiodic acid as reducing agents. The preparation of the thin graphene films is done in a similar way as the conventional VYNS foil preparation procedure. Drops of the solution are deposited onto water. The graphene films have been used to prepare sources containing some electron capture radionuclides ((109)Cd, (55)Fe, (139)Ce) with an activity in the order of 3kBq. The samples have been measured to test the attainable low energy electron efficiency and the energy resolution of Auger and conversion electrons by 4π (electron capture)-γ coincidence measurements. The 4π (electron capture)-γ coincidence setup includes a pressurized proportional counter and a NaI(Tl) detector. Tests with different pressures up to 1000kPa were carried out. All these tests show similar values in both parameters (efficiency and resolution) as those obtained by using the conventional metallized films without the drawback of the high percentage of broken films.

  19. Structure of silicon oxide films prepared by vacuum deposition

    NASA Astrophysics Data System (ADS)

    Saito, Yoshio; Kaito, Chihiro; Nishio, Kenzo; Naiki, Toshio

    1985-05-01

    The structure of thin silicon oxide films 5 nm in thickness, which were prepared by electron beam evaporation of SiO 2 glass onto a NaCl substrate, has been examined by high resolution electron microscopy and diffraction. Although the films which were prepared with substrate temperatures ranging from room up to 400°C gave rise to amorphous haloes, lattice fringes in areas 1-2 nm in extent were, however, seen in the micrographs. It is shown that the film is composed of α-quartz micro-crystallites. Crystals of α-cristobalite with sizes of several tens of nanometers appeared at a substrate temperature of 500°C. At a substrate temperature of 600°C, β-cristobalite crystals with sizes of several tens of nanometers appeared. The structural changes due to the substrate temperature were attributed to incorporation of sodium atoms from the substrate into the SiO 2 film.

  20. Nanoindentation on carbon thin films obtained from a C 60 ion beam

    NASA Astrophysics Data System (ADS)

    Dall'Asén, A. G.; Verdier, M.; Huck, H.; Halac, E. B.; Reinoso, M.

    2006-09-01

    Raman spectra, atomic force microscope (AFM) images, hardness ( H) and Young's modulus ( E) measurements were carried out in order to characterize carbon thin films obtained from a C 60 ion beam on silicon substrates at different deposition energies (from 100 up to 500 eV). The mechanical properties were studied via the nanoindentation technique. It has been observed by Raman spectroscopy and AFM that the microstructure presents significant changes for films deposited at energies close to 300 eV. However, these remarkable changes have not been noticeable on the mechanical properties: apparently H and E increase with higher deposition energy up to ˜11 and ˜116 GPa, respectively. These values are underestimated if the influence of the film roughness is not taken into account.

  1. Preparation of large-area double-walled carbon nanotube films and application as film heater

    NASA Astrophysics Data System (ADS)

    Wu, Zi Ping; Wang, Jian Nong

    2009-11-01

    Large-area (larger than 30×30 cm 2) double-walled carbon nanotube (DWCNT) films are prepared and application as a heating element for film heaters is demonstrated. A high heating efficiency is observed. Measurements indicate that the use of the DWCNT film heater would save energy consumption up to 20-30% when compared with a commercial film-like metal-based heater. Morphological analysis reveals that the special surface structure, appropriate electric and high thermal conductivities of the film formed by the network of entangled nanotube bundles may lead to the high heating performance. Considering large-area, shape flexibility, negligible weight and easy manipulation, the film exhibits promising potential applications as a film heater for thermal control in aircrafts, medical equipment, home appliances and other industrial fields at low temperature (below 400 °C).

  2. Advanced Functional Thin Films Prepared by Plasma CVD

    NASA Astrophysics Data System (ADS)

    Takai, Osamu

    1998-10-01

    Recently water repellency has been required for many types of substrate (e.g. glass, plastics, fibers, ceramics and metals) in various industrial fields. This paper reports on the preparation of highly water-repellent thin films by plasma CVD (PCVD). We have prepared transparent water-repellent thin films at low substrate temperatures by two types of PCVD, rf PCVD and microwave PCVD, using fluoro-alkyl silanes (FASs) as source gases. Silicon oxide thin films contained fluoro-alkyl functions were deposited onto glass and plastics, and realized the excellent water repellency like polytetrafluoroetylene (PTFE) and the high transparency like glass. Increasing the deposition pressure we have formed ultra water-repellent (contact angle for a water drop of over about 150 degrees) thin films by microwave PCVD using a multiple gas mixture of tetramethylsilane (TMS), (heptadecafluoro-1,1,2,2-tetrahydro-decyl)-1-trimethoxysilane (FAS-17) and argon. Ultra water-repellency appears at higher total pressures over 40 Pa because the surface becomes rough due to the growth of large particles. The color of these ultra water-repellent films is slightly white because of the scattering of light by the large particles. Recently we have also deposited transparent ultra water-repellent thin films at low substrate temperatures by microwave PCVD using organosilicon compounds without fluorine as source gases. We evaluated water repellency, optical transmittance, surface morphology and chemical composition of the deposited films. At the suitable substrate position the deposited film gave the contact angle of about 150 degrees and the transmittance of over 80 visible region for a coated glass (thickness was about 1 micron). The control of the surface morphology of the deposited films is most important to obtain the transparent ultra water-repellent films.

  3. Spectroscopic Study of Plasma Polymerized a-C:H Films Deposited by a Dielectric Barrier Discharge

    PubMed Central

    Chandrashekaraiah, Thejaswini Halethimmanahally; Bogdanowicz, Robert; Rühl, Eckart; Danilov, Vladimir; Meichsner, Jürgen; Thierbach, Steffen; Hippler, Rainer

    2016-01-01

    Plasma polymerized a-C:H thin films have been deposited on Si (100) and aluminum coated glass substrates by a dielectric barrier discharge (DBD) operated at medium pressure using C2Hm/Ar (m = 2, 4, 6) gas mixtures. The deposited films were characterized by Fourier transform infrared reflection absorption spectroscopy (FT-IRRAS), Raman spectroscopy, and ellipsometry. FT-IRRAS revealed the presence of sp3 and sp2 C–H stretching and C–H bending vibrations of bonds in the films. The presence of D and G bands was confirmed by Raman spectroscopy. Thin films obtained from C2H4/Ar and C2H6/Ar gas mixtures have ID/IG ratios of 0.45 and 0.3, respectively. The refractive indices were 2.8 and 3.1 for C2H4/Ar and C2H6/Ar films, respectively, at a photon energy of 2 eV. PMID:28773715

  4. Urine Cytology: Collection, Film Preparation, and Evaluation.

    PubMed

    Vap, Linda M; Shropshire, Sarah B

    2017-01-01

    Cytologic examination of the urine sediment in animals suspected of having urinary tract disease or lower urinary tract masses is one of the best means of distinguishing inflammation, infection, and neoplasia and can help determine if a positive dipstick result for hemoglobin/blood is due to hemorrhage or blood contamination. The quality of the specimen collection and handling plays an important role in the quality of results, the validity of interpretations, and selection of appropriate course of action. The method of sample collection aids localization of pathology. Air dry but do not heat fix, freeze, or expose films to formalin fumes, temperature extremes, or condensation.

  5. How to reduce the Al-texture in AlN films during film preparation

    NASA Astrophysics Data System (ADS)

    Yin, Ju-qian; Chen, Xi-ming; Yang, Bao-he; Zhang, Qian; Wu, Xiao-guo

    2012-09-01

    The preparation of aluminum nitrogen (AlN) film without Al texture is of great significance for the manufacture of high-performance surface acoustic wave (SAW) device. We research the process factors which bring Al into AlN film due to radio frequency (RF) magnetron sputtering system, and discuss how the process parameters influence the AlN thin film containing Al. In the research, it is found that the high sputtering power, the low deposition pressures and low partial pressure of Ar can lead to growing Al-texture during AlN thin film preparation, and the experiment also shows that filling the chamber with nitrogen gas can recrystallize a small amount of Al composition into AlN film during the annealing process in the high temperature environment.

  6. /dopamine films prepared by sol-gel method

    NASA Astrophysics Data System (ADS)

    Valverde-Aguilar, G.; Prado-Prone, G.; Vergara-Aragón, P.; Garcia-Macedo, J.; Santiago, Patricia; Rendón, Luis

    2014-09-01

    Dopamine was encapsulated into nanoporous amorphous TiO2 matrix by sol-gel method under atmospheric conditions. A second sample was obtained by the addition of the crown-ether 15C5 in this previous sample. Thin films were spin-coated on glass wafers. No heat treatment was employed in both films. All films were characterized using infrared spectroscopy, high resolution transmission electronic microscopy, X-ray diffraction, optical absorption and scanning electronic microscopy. Despite the films prepared with 15C5 were no calcined, a partial crystallization was identified. Anatase and rutile nanoparticles with sizes of 4-5 nm were obtained. Photoconductivity technique was used to determine the charge transport mechanism on these films. Experimental data were fitted with straight lines at darkness and under illumination wavelengths at 320, 400, and 515 nm. It indicates an ohmic behavior. Photovoltaic and photoconductivity parameters were determined from the current density vs. the applied-electrical-field results. Amorphous film has bigger photovoltaic and photoconductive parameters than the partially crystalline film. Results observed in the present investigation prove that the nanoporous TiO2 matrix can protect the dopamine inhibiting its chemical instability. This fact modifies the optical, physical and electrical properties of the film, and is intensified when 15C5 is added.

  7. Sol-gel preparation of silica and titania thin films

    NASA Astrophysics Data System (ADS)

    Thoř, Tomáš; Václavík, Jan

    2016-11-01

    Thin films of silicon dioxide (SiO2) and titanium dioxide (TiO2) for application in precision optics prepared via the solgel route are being investigated in this paper. The sol-gel process presents a low cost approach, which is capable of tailoring thin films of various materials in optical grade quality. Both SiO2 and TiO2 are materials well known for their application in the field of anti-reflective and also highly reflective optical coatings. For precision optics purposes, thickness control and high quality of such coatings are of utmost importance. In this work, thin films were deposited on microscope glass slides substrates using the dip-coating technique from a solution based on alkoxide precursors of tetraethyl orthosilicate (TEOS) and titanium isopropoxide (TIP) for SiO2 and TiO2, respectively. As-deposited films were studied using spectroscopic ellipsometry to determine their thickness and refractive index. Using a semi-empirical equation, a relationship between the coating speed and the heat-treated film thickness was described for both SiO2 and TiO2 thin films. This allows us to control the final heat-treated thin film thickness by simply adjusting the coating speed. Furthermore, films' surface was studied using the white-light interferometry. As-prepared films exhibited low surface roughness with the area roughness parameter Sq being on average of 0.799 nm and 0.33 nm for SiO2 and TiO2, respectively.

  8. The preparation, characterization, and application of thin film devices

    NASA Astrophysics Data System (ADS)

    Berno, Bob

    This thesis deals with the preparation of two thin film devices, in particular a nitrogen dioxide (NOsb2) gas sensor and a rechargeable lithium battery. A number of different thin film preparation techniques were used for a variety of applications and the resultant films were characterized by spectroscopic and electrochemical methods. The NOsb2 gas sensor was based on Langmuir-Blodgett (LB) monolayer films of the sandwich molecule europium bisphthalocyanine (EuPcsb2). The intense UV-visible absorption spectrum of a monolayer of the EuPcsb2 dye molecules was recorded before and after exposure to NOsb2 gas. It was noted that with time the film spectrum returned to its original colour, thus indicating the process to be reversible. The powerful spectroscopic technique of surface enhanced Raman scattering (SERS) was also utilized for film characterization. As with the absorption spectroscopy, the SERS experiments also indicated a reversible NOsb2 adsorption-desorption process. An interdigitated gold electrode was used to measure the electrical conductivity of LB monolayers of EuPcsb2. The activation energy for conduction for this molecular semiconductor was determined to be 0.27 eV from thermal conductivity experiments. Upon exposure to NOsb2 gas, the conductivity of the film increases considerably until it reaches saturation. Kinetics studies indicated that the conductivity changes resulted from two sources: the adsorption of NOsb2 molecules on the surface, and the absorption of the molecules into the film. While the spectroscopic experiments suggested this process to be completely reversible, the electrical measurements indicated that heating was required to remove the residual absorbed NOsb2. Thin film cathodes for a rechargeable lithium battery were fabricated by the magnetron sputtering technique. The cathodes were deposited from a sample of the LiMnsb2Osb4 pure spinel material. The Li-Mn-O film was characterized by grazing angle x-ray diffraction, Raman and

  9. Electrochemical preparation of hematite nanostructured films for solar hydrogen production

    NASA Astrophysics Data System (ADS)

    Kazemi, N.; Maghsoudipour, A.; Ebadzadeh, T.

    2012-10-01

    Photoelectrochemical water splitting is a clean and promising technique for using a renewable source of energy, i.e., solar energy, to produce hydrogen. In this work electrochemical formation of iron oxyhydroxide and its conversion to hematite (α- Fe2O3) through thermal treatment have been studied. Oxyhydroxide iron compounds have been prepared onto SnO2/F covered glass substrate by potential cycling with two different potential sweep rate values; then calcined at 520 °C in air to obtain α-Fe2O3 nanostrutured films for their implementation as photoanode in a photoelectrochemical cell. X-ray diffraction analysis allowed finding that iron oxides films have nanocrystalline character. Scanning electron microscopy revealed that films have nanostructured morphology. The obtained results are discussed considering the influence of potential sweep rate employed during the preparation of iron oxyhydroxide film on optical, structural and morphological properties of hematite nanostructured films. Results show that films have acceptable characteristics as photoanode in a photoelectrochemical cell for hydrogen generation from water.

  10. Preparation and Characterization of Ultrathin Stainless Steel Films

    SciTech Connect

    Sahoo, B.; Schlage, K.; Roehlsberger, R.; Major, J.; Hoersten, U. von; Keune, W.; Wende, H.

    2011-06-30

    We report on the preparation of polycrystalline austenitic 310 ({sup 57}Fe{sub 0.55}Cr{sub 0.25}Ni{sub 0.20}) stainless steel (SS) thin films on Si substrates and the characterization of their residual magnetism via {sup 57}Fe conversion-electron Moessbauer spectroscopy (CEMS). The films were structurally characterized at room temperature by X-ray diffraction (XRD). The virgin films were found to be structurally disordered. Subsequent annealing at moderate temperatures in ultrahigh vacuum produces the ordered martensitic and austenitic SS phases. Further annealing at higher temperatures (up to temperatures where long-range diffusion into the substrate is still weak) transforms the films into the austenitic phase with no trace of a magnetic hyperfine interaction. However, when a 2 nm thick SS thin film is embedded between two carbon layers, the as prepared disordered SS film does not transform to the martensitic or austenitic SS phase irrespective of the annealing temperature, probably because the interdiffusion with C prohibits the formation of these phases.

  11. Preparation and Characterization of Ultrathin Stainless Steel Films

    NASA Astrophysics Data System (ADS)

    Sahoo, B.; Schlage, K.; Major, J.; von Hörsten, U.; Keune, W.; Wende, H.; Röhlsberger, R.

    2011-06-01

    We report on the preparation of polycrystalline austenitic 310 (57Fe0.55Cr0.25Ni0.20) stainless steel (SS) thin films on Si substrates and the characterization of their residual magnetism via 57Fe conversion-electron Mössbauer spectroscopy (CEMS). The films were structurally characterized at room temperature by X-ray diffraction (XRD). The virgin films were found to be structurally disordered. Subsequent annealing at moderate temperatures in ultrahigh vacuum produces the ordered martensitic and austenitic SS phases. Further annealing at higher temperatures (up to temperatures where long-range diffusion into the substrate is still weak) transforms the films into the austenitic phase with no trace of a magnetic hyperfine interaction. However, when a 2 nm thick SS thin film is embedded between two carbon layers, the as prepared disordered SS film does not transform to the martensitic or austenitic SS phase irrespective of the annealing temperature, probably because the interdiffusion with C prohibits the formation of these phases.

  12. Preparation and characterisation of zein and chitosan edible film

    USDA-ARS?s Scientific Manuscript database

    The aim of this work was to develop zein/chitosan blends and study the heat effect on chitosan in the film-making process. The zein and chitosan solutions were prepared separately; two different chitosan solutions were produced, one heated at 80 ºC for 1 h, and another just stirred for 1 h and unhea...

  13. Preparation and adhesion of ultrathin polyimide films on polycrystalline silver

    NASA Astrophysics Data System (ADS)

    Grunze, M.; Lamb, R. N.

    1987-01-01

    4.4-oxydianiline (ODA) and 1,2,3,5-benzenetetracarboxylic anhydride (PMDA) were deposited from the vapor phase onto a polycrystalline silver substrate and polymerization of the two components to form ultrathin polyimide films ( d≈ 11 Å) was followed by X-ray photoelectron spectroscopy. Both PMDA and ODA chemisorb on the clean surface under partial fragmentation. Co-deposition of ODA and PMDA followed by heating of the substrate led to formation of thermally stable ( T<450°C) polyimide films. Our data indicate that adhesion of the polyimide film to the surface involves chemical bonding to fragmented PMDA and/or ODA chemisorbed on the substrate. Our experiments show that polyimide films can be prepared sufficiently thin to allow the application of surface sensitive techniques to probe the substrate-polymer interface and to study the basic physics and chemistry of adhesion.

  14. Preparation Of Copper Indium Gallium Diselenide Films For Solar Cells

    DOEpatents

    Bhattacharya, Raghu N.; Contreras, Miguel A.; Keane, James; Tennant, Andrew L. , Tuttle, John R.; Ramanathan, Kannan; Noufi, Rommel

    1998-08-08

    High quality thin films of copper-indium-gallium-diselenide useful in the production of solar cells are prepared by electrodepositing at least one of the constituent metals onto a glass/Mo substrate, followed by physical vapor deposition of copper and selenium or indium and selenium to adjust the final stoichiometry of the thin film to approximately Cu(In,Ga)Se.sub.2. Using an AC voltage of 1-100 KHz in combination with a DC voltage for electrodeposition improves the morphology and growth rate of the deposited thin film. An electrodeposition solution comprising at least in part an organic solvent may be used in conjunction with an increased cathodic potential to increase the gallium content of the electrodeposited thin film.

  15. Preparing polymer brushes on polytetrafluoroethylene films by free radical polymerization

    NASA Astrophysics Data System (ADS)

    Sun, Wei; Chen, Yiwang; Deng, Qilan; Chen, Lie; Zhou, Lang

    2006-11-01

    Films of polytetrafluoroethylene (PTFE) were exposed to sodium naphthalenide (Na/naphtha) etchant so as to defluorinate the surface for obtaining hydroxyl functionality. Surface-initiators were immobilized on the PTFE films by esterification of 4,4‧-azobis(4-cyanopentanoic acid) (ACP) and the hydroxyl groups covalently linked to the surface. Grafting of polymer brushes on the PTFE films was carried out by the surface-initiated free radical polymerization. Homopolymers brushes of methyl methacrylate (MMA) were prepared by free radical polymerization from the azo-functionalized PTFE surface. The chemical composition and topography of the graft-functionalized PTFE surfaces were characterized by X-ray photoelectron spectroscopy (XPS), attenuated total reflectance (ATR) FT-IR spectroscopy and atomic force microscopy (AFM). Water contact angles on PTFE films were reduced by surface grafting of MMA.

  16. Preparation and properties of cellulose nanocrystals reinforced collagen composite films.

    PubMed

    Li, Weichang; Guo, Rui; Lan, Yong; Zhang, Yi; Xue, Wei; Zhang, Yuanming

    2014-04-01

    Collagen films have been widely used in the field of biomedical engineering. However, the poor mechanical properties of collagen have limited its application. Here, rod-like cellulose nanocrystals (CNCs) were fabricated and used to reinforce collagen films. A series of collagen/CNCs films were prepared by collagen solution with CNCs suspensions homogeneously dispersed at CNCs: collagen weight ratios of 1, 3, 5, 7, and 10. The morphology of the resulting films was analyzed by scanning electron microscopy (SEM), the enhancement of the thermomechanical properties of the collagen/CNCs composites were demonstrated by thermal gravimetric analysis (TGA) and mechanical testing. Among the CNCs contents used, a loading of 7 wt % led to the maximum mechanical properties for the collagen/CNCs composite films. In addition, in vitro cell culture studies revealed that the CNCs have no negative effect on the cell morphology, viability, and proliferation and possess good biocompatibility. We conclude that the incorporation of CNCs is a simple and promising way to reinforce collagen films without impairing biocompatibility. This study demonstrates that the composite films show good potential for use in the field of skin tissue engineering. Copyright © 2013 Wiley Periodicals, Inc.

  17. Process for preparing superconducting film having substantially uniform phase development

    DOEpatents

    Bharacharya, R.; Parilla, P.A.; Blaugher, R.D.

    1995-12-19

    A process is disclosed for preparing a superconducting film, such as a thallium-barium-calcium-copper oxide superconducting film, having substantially uniform phase development. The process comprises providing an electrodeposition bath having one or more soluble salts of one or more respective potentially superconducting metals in respective amounts adequate to yield a superconducting film upon subsequent appropriate treatment. Should all of the metals required for producing a superconducting film not be made available in the bath, such metals can be a part of the ambient during a subsequent annealing process. A soluble silver salt in an amount between about 0.1% and about 4.0% by weight of the provided other salts is also provided to the bath, and the bath is electrically energized to thereby form a plated film. The film is annealed in ambient conditions suitable to cause formation of a superconductor film. Doping with silver reduces the temperature at which the liquid phase appears during the annealing step, initiates a liquid phase throughout the entire volume of deposited material, and influences the nucleation and growth of the deposited material. 3 figs.

  18. Process for preparing superconducting film having substantially uniform phase development

    DOEpatents

    Bharacharya, Raghuthan; Parilla, Philip A.; Blaugher, Richard D.

    1995-01-01

    A process for preparing a superconducting film, such as a thallium-barium-calcium-copper oxide superconducting film, having substantially uniform phase development. The process comprises providing an electrodeposition bath having one or more soluble salts of one or more respective potentially superconducting metals in respective amounts adequate to yield a superconducting film upon subsequent appropriate treatment. Should all of the metals required for producing a superconducting film not be made available in the bath, such metals can be a part of the ambient during a subsequent annealing process. A soluble silver salt in an amount between about 0.1% and about 4.0% by weight of the provided other salts is also provided to the bath, and the bath is electrically energized to thereby form a plated film. The film is annealed in ambient conditions suitable to cause formation of a superconductor film. Doping with silver reduces the temperature at which the liquid phase appears during the annealing step, initiates a liquid phase throughout the entire volume of deposited material, and influences the nucleation and growth of the deposited material.

  19. Thermal annealing and SHI irradiation induced modifications in sandwiched structured Carbon-gold-Carbon (a-C/Au/a-C) nanocomposite thin film

    NASA Astrophysics Data System (ADS)

    Singh, S. K.; Singhal, R.

    2017-09-01

    In the present work, we study the annealing and swift heavy ion (SHI) beam induced modifications in the optical and structural properties of sandwiched structured Carbon-gold-Carbon (a-C/Au/a-C) nanocomposite (NCs) thin films. The NCs thin films were synthesized by electron-beam evaporation technique at room temperature with ∼30 nm thickness for both carbon layer and ∼6 nm for gold layer. Gold-carbon NCs thin films were annealed in the presence of argon at a temperature of 500 °C, 600 °C and 750 °C. The NCs thin films were also irradiated with 90 MeV Ni ions beam with different ion fluences in the range from 3 × 1012, 6 × 1012 and 1 × 1013 ions/cm2. Surface plasmon resonance (SPR) of Au nanoparticles are not observed in the pristine film but, after annealing at temperature of 600 °C and 750 °C, it was clearly seen at ∼534 nm as confirmed by UV-visible absorption spectroscopy. 90 MeV Ni irradiated thin film at the fluence of 1 × 1013 ions/cm2 also show strong absorption band at ∼534 nm. The growth and size of Au nanoparticle for pristine and 90 MeV Ni ion irradiated thin film with fluence of 1 × 1013 ions/cm2, were estimated by Transmission electron microscopy (TEM) images with the bi-model distribution. The size of the gold nanoparticle (NPs) was found to be ∼4.5 nm for the pristine film and ∼5.4 nm for the irradiated film at a fluence of 1 × 1013 ions/cm2. The thickness and metal atomic fraction in carbon matrix were estimated by Rutherford backscattering spectroscopy (RBS). The effect of annealing as well as heavy ion irradiation on D and G band of carbon matrix were studied by Raman spectroscopy.

  20. Tuning of the microstructure, mechanical and tribological properties of a-C:H films by bias voltage of high frequency unipolar pulse

    NASA Astrophysics Data System (ADS)

    Wang, Jia; Cao, Zhongyue; Pan, Fuping; Wang, Fuguo; Liang, Aimin; Zhang, Junyan

    2015-11-01

    Amorphous hydrogenated carbon (a-C:H) films were prepared by high frequency unipolar pulse plasma-enhanced chemical vapor deposition in CH4, Ar, and H2 atmosphere with the bias voltage in the range of -800 -1600 V. The microstructures and mechanical properties of a-C:H films were investigated via high resolution transmission electron microscope (HRTEM), Raman spectroscopy, and Nanoindenter. The results reveal that the curved and straight graphitic microstructures appear in amorphous carbon matrix, and their contents increase obviously with the bias voltage. At the same time, the corresponding hardness decreases and elastic recovery increases, however even in such a case films still possess excellent mechanical properties. According to the tribological property characterization, we believe that the bias voltage also influences their tribological performances significantly, the higher the bias voltage finally gets, the lower the friction coefficient and wear rate occur. These results indicate that the microstructures of a-C:H films can be tuned efficiently by bias voltage and the films with good mechanical and tribological properties can be obtained at a higher range.

  1. Positron beam studies of saponite film prepared by precipitation method

    NASA Astrophysics Data System (ADS)

    Numata, K.; Sato, K.; Fujimoto, K.; Ito, K.

    2017-01-01

    Micrometer-sized saponite particles were isolated by means of gravitational sedimentation method applying Stokes’ law. The sample prepared with this method was film-like state with a thickness of ~ 30 μm and was semitransparent, indicating that the particles are homogeneously stacked all together. Positron lifetime spectroscopy using a slow positron beam yielded two components for ortho-positronium with lifetimes of 1.5 ns and 8.4 ns with the respective relative intensities of 13 % and 10 %. The results suggest that the self-assembly of the larger particles toward structural densification is suppressed for the present film in comparison with the smaller nanoparticles.

  2. Controlling Marangoni-induced instabilities in spin-cast polymer films: How to prepare uniform films.

    PubMed

    Fowler, Paul D; Ruscher, Céline; McGraw, Joshua D; Forrest, James A; Dalnoki-Veress, Kari

    2016-09-01

    In both research and industrial settings spincoating is extensively used to prepare highly uniform thin polymer films. However, under certain conditions, spincoating results in films with non-uniform surface morphologies. Although the spincoating process has been extensively studied, the origin of these morphologies is not fully understood and the formation of non-uniform spin-cast films remains a practical problem. Here we report on experiments demonstrating that the formation of surface instabilities during spincoating is dependent on temperature. Our results suggest that non-uniform spin-cast films form as a result of the Marangoni effect, which describes flow due to surface tension gradients. We find that both the wavelength and amplitude of the pattern increase with temperature. Finally, and most important from a practical viewpoint, the non-uniformities in the film thickness can be entirely avoided simply by lowering the spin coating temperature.

  3. Nanocomposite nc-TiC/a-C thin films for electrical contact applications

    SciTech Connect

    Lewin, Erik; Wilhelmsson, Ola; Jansson, Ulf

    2006-09-01

    Thin film nanocomposites of nanocrystalline TiC embedded in a matrix of amorphous carbon have been prepared by nonreactive unbalanced dc-magnetron sputtering. These samples have been tested as coating materials for electrical contacts and show great potential as an alternative to traditional metallic coatings for contacts subjected to wear and friction. Through variation of composition and deposition temperature different microstructures have been attained. The coatings have been characterized using x-ray diffraction, x-ray photoelectron spectroscopy, and Raman spectroscopy. The performance of the coatings has been coupled to the microstructure whereby tuning and optimization possibilities have been identified.

  4. Ferrimagnetic thin films prepared by pulsed laser deposition

    NASA Astrophysics Data System (ADS)

    Guyot, M.; Lisfi, A.; Krishnan, R.; Porte, M.; Rougier, P.; Cagan, V.

    1996-04-01

    Thin films, with thickness ranging from 25 nm up to 1.5 μm, of well-known ferrimagnetic materials such as NiFe 2O 4, CoFe 2O 4, Ni 0.5Zn 0.5Fe 2O 4, and BaFe 12O 19 have been prepared by PLD. Films made at low substrate temperature ( T < 500° C) are amorphous, but can crystallize by post-annealing in air in the temperature range 500-800°C. Films deposited at temperature between 500 and 800°C are polycrystalline, the grain size (from 50 nm to 1 μm) and surface roughness (1-100 nm) depending upon deposition parameters. The polycrystalline films are ferrimagnetic with a saturation magnetization close to the bulk value ( Js = 0.3 T for Ni-ferrites). Spinel films are isotropic as deduced from torque balance measurements. Coercivities are rather high for the spinel films (up to 500 Oe for Ni-ferrite) and even higher for the hexaferrites (3 kOe).

  5. Tunicate cellulose nanocrystals: preparation, neat films and nanocomposite films with glucomannans.

    PubMed

    Zhao, Yadong; Zhang, Yujia; Lindström, Mikael E; Li, Jiebing

    2015-03-06

    Cellulose nanocrystals (CNs) were prepared from tunicate by enzymatic hydrolysis (ECN), TEMPO-mediated oxidation (TCN) and acid hydrolysis (ACN). They were cast alone or blended with glucomannan (GM) from konjac or spruce to prepare films. Different CNs were obtained with a yield of ECN>TCN>ACN with corresponding order of decreased Mw but increased crystallinity. The CNs' diameters were on the nanometre scale, with lengths of ECN>TCN>ACN. For CN-films, TCN and ACN fibrils were stretched and parallel to each other due to surface charges. For CN-GM films, both components interacted strongly with each other, resulting in changes of crystallinity, specific surface area, fibril diameter and contact angle compared with CN films. The composite films had good thermal, optical and mechanical properties; the last ones are apparently better than similar films reported in the literature. This is the first systematic study of different tunicate CN-GM nanocomposite films and the first ever for spruce GM.

  6. Preparation and Characterization of Silver Selenide Thin Film

    NASA Astrophysics Data System (ADS)

    Chandrasekar, L. Bruno; Vijayalakshmi, R.; Rajeswari, B.; Chandramohan, R.; Arivazhagan, G.; Packiaseeli, S. Arulmozhi

    2014-12-01

    Silver selenide, a phase-changing chalcogenide material, is prepared using electro deposition method for various molarities. X-ray diffraction studies show the cubic lattice of the material. The micro-structural properties such as grain size, strain, dislocation density, and texture coefficient are examined. The lattice constant is calculated using Nelson-Relay function. Morphological studies are done and uniform distributions of grains are observed. High purities of thin films are confirmed by energy dispersive X-ray analysis. The band gap is calculated using UV-vis spectroscopy and photoluminescence technique, and hence, the Stokes's effect is observed in silver selenide thin films. It is the first time that the lattice constant and the Urbach energy for various molarities in the case of silver selenide thin films are reported.

  7. Preparation and characterisation of compositionally graded SmCo films

    NASA Astrophysics Data System (ADS)

    Dias, Andre; Gomez, Gabriel; Givord, Dominique; Bonfim, Marlio; Dempsey, Nora M.

    2017-05-01

    A compositionally graded SmCo film has been prepared by magnetron sputtering using a Co target partially covered by a Sm foil. The film was deposited onto a 100 mm thermally oxidised Si substrate and then annealed ex-situ. The SmCo film has been used as a test sample to validate an in-house developed scanning MOKE (Magneto-Optic Kerr effect) system incorporating a pulsed magnetic field source capable of producing fields as high as 10 T. A 2D array of hysteresis loops was measured across the entire wafer. The evolution in coercivity measured along a selected 1D strip of the sample is correlated with changes in composition and crystallographic structures measured using Energy Dispersive Spectroscopy and X-ray diffraction. The high field Scanning MOKE system holds much potential for optimizing the extrinsic properties of known hard magnetic phases as well as in the search for new hard magnetic phases.

  8. Growth mechanism and composition of ultrasmooth a-C:H:Si films grown from energetic ions for superlubricity

    NASA Astrophysics Data System (ADS)

    Chen, Xinchun; Kato, Takahisa

    2014-01-01

    Growth mechanism and ion energy dependence of composition of ultrasmooth a-C:H:Si films grown from ionization of tetramethylsilane (TMS) and toluene mixture at a fixed gas ratio have been investigated by varying the applied bias voltage. The dynamic scaling theory is employed to evaluate the roughness evolution of a-C:H:Si films, and to extract roughness and growth exponents of α ˜ 0.51 and β ˜ 0, respectively. The atomically smooth surface of a-C:H:Si films with Ra ˜ 0.1 nm is thermally activated by the energetic ion-impact induced subsurface "polishing" process for ion dominated deposition. The ion energy (bias voltage) plays a paramount role in determining the hydrogen incorporation, bonding structure and final stoichiometry of a-C:H:Si films. The hydrogen content in the films measured by ERDA gradually decreases from 36.7 to 17.3 at. % with increasing the bias voltage from 0.25 to 3.5 kV, while the carbon content in the films increases correspondingly from 52.5 to 70.1 at. %. The Si content is kept almost constant at ˜9-10 at. %. Depending on the ion-surface interactions, the bonding structure of a-C:H:Si films grown in different ion energy regions evolves from chain-developed polymer-like to cross-linked diamond-like to sp2-bonded a-C as revealed by XPS, Raman, and FTIR analysis. Such a structural evolution is reflected in their measured nanomechanical properties such as hardness, modulus, and compressive stress. An enhanced viscoplastic behavior (i.e., viscoplastic exponent of ˜0.06) is observed for polymeric a-C:H:Si films. A hydrogen content threshold (H > 20 at. %) exists for the as-grown a-C:H:Si films to exhibit superlow friction in dry N2 atmosphere. An extremely low friction coefficient of ˜0.001 can be obtained for polymer-like a-C:H:Si film. These near-frictionless a-C:H:Si films are strongly promising for applications in industrial lubricating systems.

  9. PEC films prepared from Chitosan-Alginate coacervates.

    PubMed

    Yan, X; Khor, E; Lim, L Y

    2000-07-01

    Chitosan-alginate polyelectrolyte complex (PEC) have been prepared in situ in beads and microspheres. This study examines the preparation of suitable chitosan-alginate coacervates for casting into homogeneous PEC films for potential applications in packaging, controlled release systems and wound dressings. Coacervation between chitosan and alginate was rapid, but the rate may be controlled with the addition of water miscible organic solvents. Compared with ethanol and PEG200, acetone was the more promising solvent moderator. Suspensions of fine, uniformly dispersed coacervates were produced by a dropwise addition of 0.25% w/v chitosan solution (solvent: 1: 1 v/v of 2% acetic acid and acetone) into 0.25% w/v sodium alginate solution in water under rapid agitation. The PEC films were transparent and flexible. They exhibited high permeability to water vapor, but resisted complete dissolution in 0.1 M HCI, distilled water and pH 7.4 phosphate buffer solution. Microscopic heterogeneity in the films could be reduced by immersion in aqueous media, but this was accompanied by modifications in the thickness, permeability and mechanical property of the films.

  10. Structure and mechanical properties of a-C:H films deposited on a 3D target: comparative study on target scale and aspect ratio

    NASA Astrophysics Data System (ADS)

    Hirata, Y.; Choi, J.

    2017-04-01

    Recently, the bipolar-type plasma-based ion implantation and deposition (bipolar PBII&D) method has attracted large attention owing to its non-line-of-sight coating technique. In particular, bipolar PBII&D is beneficial in coating a hydrogenated amorphous carbon (a-C:H) film on a 3D target. Therefore, in this study, a-C:H films were prepared onto a complex-shaped 3D target such as macrotrench (pitch: 20 mm, aspect ratio: 1.0), microchannel (width: 100 µm, aspect ratio: 20), microtrench (pitch: 4 µm, aspect ratio: 2.0), or nanotrench (pitch: 300 nm, aspect ratio: 2.0) using bipolar PBII&D, and the film properties were evaluated. With regard to the mechanical properties, the film thickness and hardness were evaluated using a scanning electron microscope (SEM) and nanoindentation measurements, respectively. With regard to the structural properties, the microstructure of the films was evaluated by Raman spectroscopy. Subsequently, the structural and mechanical properties were compared with each other to reveal the target scale- and aspect ratio-dependence on the film properties. Furthermore, the coating mechanism was elucidated by analyzing the plasma behavior around the target using a plasma simulation method. The particle-in-cell/Monte Carlo collision (PIC-MCC) and the direct simulation Monte Carlo (DSMC) methods were simultaneously used as the plasma simulation method. Each of these is a calculation method that analyzes the behavior of ions and radicals, respectively. As a result, the a-C:H films were successfully coated onto any scale and any shape of the target. In contrast, the results of the hardness and those from the Raman spectroscopy on the sidewall surface indicated non-uniformity of the film structure and depended on the scale and aspect ratio of a target, i.e. the hardness and Raman data show different values depending on the target scale and aspect ratio. The result of the plasma simulation suggested that such non-uniform mechanical or structural

  11. Effect of a new titanium coating material (CaTiO3-aC) prepared by thermal decomposition method on osteoblastic cell response.

    PubMed

    Inoue, Miho; Rodriguez, Andrea P; Takagi, Tohru; Katase, Naoki; Kubota, Midori; Nagai, Noriyuki; Nagatsuka, Hitoshi; Inoue, Masahisa; Nagaoka, Noriyuki; Takagi, Shin; Suzuki, Kazuomi

    2010-03-01

    Titanium and hydroxyapatite (HA) are widely used as biomaterials for dental and medical applications. HA-coated titanium implants have excellent biocompatibility and mechanical properties. However, the adherence of HA film formed on titanium substrate is weak because of the lack of chemical interaction between HA and titanium. A solution to this problem is to form an intermediate film on titanium substrate, which provide excellent adherence to both titanium substrate and HA. We developed a novel biomaterial called calcium titanate-amorphous carbon (CaTiO(3)-aC) coating prepared by modified thermal decomposition method. The purpose of this study was to evaluate the effect of CaTiO(3)-aC and HA coating (positive control), and Ti (negative control) on osteoblastic (MT3T3-E1) cell responses. An increased cellular proliferation was observed in CaTiO(3)-aC coating compared to HA coating. The maximum expressions of ALP activity, Col I and ALP mRNA were higher and achieved in shorter period of time in CaTiO(3)-aC coating compared to others. These results demonstrated that CaTiO(3)-aC promoted better cell attachment, cellular proliferation, and osteoblastic differentiation compared with HA. In conclusion, we suggested that CaTiO(3)-aC could be considered as an important candidate as a coating material.

  12. Preparation and aging of sputtered tungstic oxide films

    SciTech Connect

    Akram, H.; Tatsuoka, H.; Kitao, M.; Yamada, S.

    1987-09-01

    Conditions for the preparation of electrochromic tungstic oxide films with high efficiency for coloration have been investigated. Tungstic oxide films were deposited on glass substrates by rf sputtering in Ar-O/sub 2/ mixture from a compressed powder WO/sub 3/ target. As-deposited films require an ''aging process,'' in which the density of charges extracted in bleaching is smaller than that injected in coloring. It is considered that a part of the protons introduced during the aging combine with bonds of unstable oxygen contained in the as-deposited films. After the aging period, sputtered films have reversible coloration and bleaching cycles. Maximum electrochromic coloration efficiencies are 0.09 and 0.04 cm/sup 2//mC at wavelengths of 800 and 500 nm, respectively. They are obtained when the sputtering atmosphere is 0.04--0.05-Torr total pressure and 5% oxygen content. At any rate, substrate temperature should be kept at 100 /sup 0/C or less.

  13. Preparation and properties of evaporated CdTe films

    NASA Astrophysics Data System (ADS)

    Bube, R. H.; Fahrenbruch, A. L.; Chien, K. F.

    1987-07-01

    Previous work on evaporated CdTe films for photovoltaics showed no clear path to successful p-type doping of CdTe during deposition. Post-deposition annealing of the films in various ambients thus was examined as a means of doping. Anneals were done in Te, Cd, P, and As vapors and in vacuum, air and Ar, all of which showed large effects on series resistance and diode parameters. With As, series resistance values of In/p-CdTe/graphite structures decreased markedly. This decrease was due to a decrease in grain boundary and/or back contact barrier height, and thus was due to large increases in mobility; the carrier density was not altered substantially. Although the series-resistance decreases were substantial, the diode characteristics became worse. The decreases were not observed when CdS/CdTe cells were fabricated on Te vapor-annealed films. Preparation of ZnO films by reactive evaporation yielded promising results. Deposition of p-ZnTe films by hot-wall vapor evaporation, using conventional techniques, yielded acceptable specimens.

  14. Growth mechanism and composition of ultrasmooth a-C:H:Si films grown from energetic ions for superlubricity

    SciTech Connect

    Chen, Xinchun Kato, Takahisa

    2014-01-28

    Growth mechanism and ion energy dependence of composition of ultrasmooth a-C:H:Si films grown from ionization of tetramethylsilane (TMS) and toluene mixture at a fixed gas ratio have been investigated by varying the applied bias voltage. The dynamic scaling theory is employed to evaluate the roughness evolution of a-C:H:Si films, and to extract roughness and growth exponents of α ∼ 0.51 and β ∼ 0, respectively. The atomically smooth surface of a-C:H:Si films with Ra ∼ 0.1 nm is thermally activated by the energetic ion-impact induced subsurface “polishing” process for ion dominated deposition. The ion energy (bias voltage) plays a paramount role in determining the hydrogen incorporation, bonding structure and final stoichiometry of a-C:H:Si films. The hydrogen content in the films measured by ERDA gradually decreases from 36.7 to 17.3 at. % with increasing the bias voltage from 0.25 to 3.5 kV, while the carbon content in the films increases correspondingly from 52.5 to 70.1 at. %. The Si content is kept almost constant at ∼9–10 at. %. Depending on the ion-surface interactions, the bonding structure of a-C:H:Si films grown in different ion energy regions evolves from chain-developed polymer-like to cross-linked diamond-like to sp{sup 2}-bonded a–C as revealed by XPS, Raman, and FTIR analysis. Such a structural evolution is reflected in their measured nanomechanical properties such as hardness, modulus, and compressive stress. An enhanced viscoplastic behavior (i.e., viscoplastic exponent of ∼0.06) is observed for polymeric a-C:H:Si films. A hydrogen content threshold (H > 20 at. %) exists for the as-grown a-C:H:Si films to exhibit superlow friction in dry N{sub 2} atmosphere. An extremely low friction coefficient of ∼0.001 can be obtained for polymer-like a-C:H:Si film. These near-frictionless a-C:H:Si films are strongly promising for applications in industrial lubricating systems.

  15. Haemocompatibility of hydrogenated amorphous carbon (a-C:H) films synthesized by plasma immersion ion implantation-deposition

    NASA Astrophysics Data System (ADS)

    Yang, P.; Kwok, S. C. H.; Chu, P. K.; Leng, Y. X.; Chen, J. Y.; Wang, J.; Huang, N.

    2003-05-01

    Diamond-like-carbon has attracted much attention recently as a potential biomaterial in blood contacting biomedical devices. However, previous reports in this area have not adequately addressed the biocompatibility and acceptability of the materials in blood contacting applications. In this study, hydrogenated amorphous carbon (a-C:H) films were fabricated on silicon wafers (1 0 0) using plasma immersion ion implantation-deposition. A series of a-C:H films with different structures and chemical bonds were fabricated under different substrate voltages. The results indicate that film graphitization is promoted at higher substrate bias. The film deposited at a lower substrate bias of -75 V possesses better blood compatibility than the films at higher bias and stainless steel. Our results suggest two possible paths to improve the blood compatibility, suppression of the endogenic clotting system and reduction of platelet activation.

  16. A magnetron sputtering system for the preparation of patterned thin films and in situ thin film electrical resistance measurements

    SciTech Connect

    Arnalds, U. B.; Agustsson, J. S.; Ingason, A. S.; Eriksson, A. K.; Gylfason, K. B.; Gudmundsson, J. T.; Olafsson, S.

    2007-10-15

    We describe a versatile three gun magnetron sputtering system with a custom made sample holder for in situ electrical resistance measurements, both during film growth and ambient changes on film electrical properties. The sample holder allows for the preparation of patterned thin film structures, using up to five different shadow masks without breaking vacuum. We show how the system is used to monitor the electrical resistance of thin metallic films during growth and to study the thermodynamics of hydrogen uptake in metallic thin films. Furthermore, we demonstrate the growth of thin film capacitors, where patterned films are created using shadow masks.

  17. Langmuir-Blodgett films of cellulose nanocrystals: preparation and characterization.

    PubMed

    Habibi, Youssef; Foulon, Laurence; Aguié-Béghin, Véronique; Molinari, Michaël; Douillard, Roger

    2007-12-15

    The goal of this work is the preparation of monolayers of cellulose I nanocrystals providing flat crystalline cellulose surfaces. Suspensions of cellulose nanocrystals were prepared by hydrolyzing ramie and tunicin fibers with sulfuric acid. Due to surface grafted sulfate groups, the negatively charged, rod-like cellulose nanocrystals were found to form stable layers at the air-water interface in the presence of a cationic amphiphilic molecule such as dioctadecyldimethylammonium (DODA) used in this work. These layers were formed at different cellulose-DODA weight ratios, compressed and analyzed by tensiometry, ellipsometry and Brewster angle microscopy. At low cellulose concentrations the layers are discontinuous, becoming dense and homogeneous upon reaching a critical weight ratio, which depends on the aspect ratio of the cellulose nanocrystals. After transfer onto silicon wafers, the surface composition and morphology as well as the thickness of the films were examined by X-ray photoelectron spectroscopy, ellipsometry and atomic force microscopy. The results indicate that they are monolayer films, well structured, relatively smooth and pure. These films offer a crystalline and easily reproducible model cellulose surface.

  18. Nanostructural and mechanical properties of nanocomposite nc-TiC/a-C:H films deposited by reactive unbalanced magnetron sputtering

    NASA Astrophysics Data System (ADS)

    Zehnder, T.; Schwaller, P.; Munnik, F.; Mikhailov, S.; Patscheider, J.

    2004-04-01

    Thin films of nc-TiC/a-C:H nanocomposite have been deposited by reactive magnetron sputtering at substrate bias values of -240 and -91 V. The grain size and grain separation, which together define the nanostructure, are correlated to the amount of the amorphous phase. From the size of the TiC grains measured by x-ray diffraction and the amorphous hydrogenated carbon (a-C:H) phase content determined by x-ray photoelectron spectroscopy, the mean grain separation is estimated using a simple model for the nanostructure. Films deposited at -240 V show a hardness enhancement for a-C:H phase contents in the range 10% to 30% with TiC grain sizes around 5 nm. The mean grain separation for such films was estimated to be 0.3 nm. Films with higher a-C:H phase contents still have 5 nm small grains, but their mean grain separation is larger than 0.5 nm; their hardness is thus determined by the properties of the amorphous matrix. A less pronounced hardness enhancement is observed for films deposited at -91 V. They have larger grains and larger mean gain separations and show smaller hardness values. The hardness of the films, among other mechanical properties, is controlled by the nanostructure. Raman measurements have shown that a-C:H is present in films with mean grain separation down to 0.2 nm. Coefficients of friction against steel lower than 0.3, independent of the substrate bias, are found for films with mean grain separations as low as 0.15 nm. Self-lubrication due to a-C:H can explain the observed friction behavior, although the presence of a-C:H cannot be proved by Raman spectroscopy for films with mean grain separations smaller than 0.2 nm. It is shown that the substrate bias is crucial in obtaining increased hardness of nc-TiC/a-C:H nanocomposite thin films. In contrast to the hardness of the coatings, their friction behavior is not affected by the substrate bias.

  19. Microwave a.c. conductivity of domain walls in ferroelectric thin films

    SciTech Connect

    Tselev, Alexander; Yu, Pu; Cao, Ye; Dedon, Liv R.; Martin, Lane W.; Kalinin, Sergei V.; Maksymovych, Petro

    2016-05-31

    Ferroelectric domain walls are of great interest as elementary building blocks for future electronic devices due to their intrinsic few-nanometre width, multifunctional properties and field-controlled topology. To realize the electronic functions, domain walls are required to be electrically conducting and addressable non-destructively. However, these properties have been elusive because conducting walls have to be electrically charged, which makes them unstable and uncommon in ferroelectric materials. Here we reveal that spontaneous and recorded domain walls in thin films of lead zirconate and bismuth ferrite exhibit large conductance at microwave frequencies despite being insulating at d.c. We explain this effect by morphological roughening of the walls and local charges induced by disorder with the overall charge neutrality. a.c. conduction is immune to large contact resistance enabling completely non-destructive walls read-out. Finally, this demonstrates a technological potential for harnessing a.c. conduction for oxide electronics and other materials with poor d.c. conduction, particularly at the nanoscale.

  20. Microwave a.c. conductivity of domain walls in ferroelectric thin films

    DOE PAGES

    Tselev, Alexander; Yu, Pu; Cao, Ye; ...

    2016-05-31

    Ferroelectric domain walls are of great interest as elementary building blocks for future electronic devices due to their intrinsic few-nanometre width, multifunctional properties and field-controlled topology. To realize the electronic functions, domain walls are required to be electrically conducting and addressable non-destructively. However, these properties have been elusive because conducting walls have to be electrically charged, which makes them unstable and uncommon in ferroelectric materials. Here we reveal that spontaneous and recorded domain walls in thin films of lead zirconate and bismuth ferrite exhibit large conductance at microwave frequencies despite being insulating at d.c. We explain this effect by morphologicalmore » roughening of the walls and local charges induced by disorder with the overall charge neutrality. a.c. conduction is immune to large contact resistance enabling completely non-destructive walls read-out. Finally, this demonstrates a technological potential for harnessing a.c. conduction for oxide electronics and other materials with poor d.c. conduction, particularly at the nanoscale.« less

  1. Microwave a.c. conductivity of domain walls in ferroelectric thin films

    NASA Astrophysics Data System (ADS)

    Tselev, Alexander; Yu, Pu; Cao, Ye; Dedon, Liv R.; Martin, Lane W.; Kalinin, Sergei V.; Maksymovych, Petro

    2016-05-01

    Ferroelectric domain walls are of great interest as elementary building blocks for future electronic devices due to their intrinsic few-nanometre width, multifunctional properties and field-controlled topology. To realize the electronic functions, domain walls are required to be electrically conducting and addressable non-destructively. However, these properties have been elusive because conducting walls have to be electrically charged, which makes them unstable and uncommon in ferroelectric materials. Here we reveal that spontaneous and recorded domain walls in thin films of lead zirconate and bismuth ferrite exhibit large conductance at microwave frequencies despite being insulating at d.c. We explain this effect by morphological roughening of the walls and local charges induced by disorder with the overall charge neutrality. a.c. conduction is immune to large contact resistance enabling completely non-destructive walls read-out. This demonstrates a technological potential for harnessing a.c. conduction for oxide electronics and other materials with poor d.c. conduction, particularly at the nanoscale.

  2. Microwave a.c. conductivity of domain walls in ferroelectric thin films.

    PubMed

    Tselev, Alexander; Yu, Pu; Cao, Ye; Dedon, Liv R; Martin, Lane W; Kalinin, Sergei V; Maksymovych, Petro

    2016-05-31

    Ferroelectric domain walls are of great interest as elementary building blocks for future electronic devices due to their intrinsic few-nanometre width, multifunctional properties and field-controlled topology. To realize the electronic functions, domain walls are required to be electrically conducting and addressable non-destructively. However, these properties have been elusive because conducting walls have to be electrically charged, which makes them unstable and uncommon in ferroelectric materials. Here we reveal that spontaneous and recorded domain walls in thin films of lead zirconate and bismuth ferrite exhibit large conductance at microwave frequencies despite being insulating at d.c. We explain this effect by morphological roughening of the walls and local charges induced by disorder with the overall charge neutrality. a.c. conduction is immune to large contact resistance enabling completely non-destructive walls read-out. This demonstrates a technological potential for harnessing a.c. conduction for oxide electronics and other materials with poor d.c. conduction, particularly at the nanoscale.

  3. Microwave a.c. conductivity of domain walls in ferroelectric thin films

    PubMed Central

    Tselev, Alexander; Yu, Pu; Cao, Ye; Dedon, Liv R.; Martin, Lane W.; Kalinin, Sergei V.; Maksymovych, Petro

    2016-01-01

    Ferroelectric domain walls are of great interest as elementary building blocks for future electronic devices due to their intrinsic few-nanometre width, multifunctional properties and field-controlled topology. To realize the electronic functions, domain walls are required to be electrically conducting and addressable non-destructively. However, these properties have been elusive because conducting walls have to be electrically charged, which makes them unstable and uncommon in ferroelectric materials. Here we reveal that spontaneous and recorded domain walls in thin films of lead zirconate and bismuth ferrite exhibit large conductance at microwave frequencies despite being insulating at d.c. We explain this effect by morphological roughening of the walls and local charges induced by disorder with the overall charge neutrality. a.c. conduction is immune to large contact resistance enabling completely non-destructive walls read-out. This demonstrates a technological potential for harnessing a.c. conduction for oxide electronics and other materials with poor d.c. conduction, particularly at the nanoscale. PMID:27240997

  4. [Preparation and spectroscopic properties of terbium polypropenic acid film].

    PubMed

    Wang, Xi-gui; Wu, Hong-ying; Weng, Shi-fu; Wu, Jin-guang

    2002-12-01

    The bonding-type rare earth polymers-polypropenic-acid terbium film was prepared through the bonding way. Three-dimension fluorescence spectra showed that the optimum excitation wavelength was 306 nm, the strongest emission wavelength was 544 nm. The terbium polypropenic-acid film showed the characteristic Tb3+ emission when excited at 306 nm due to 5D4-7FJ transition (J = 6, 5, 4 and 3). The emission maximum at 544 nm was ascribed to 5D4-7F5 transition of Tb3+ and presented strong green emission. The luminescent properties of Tb3+ were not affected by polymerism of propenic-acid and the transparency of polypropenic-acid in visible light region was not affected by the dopping Tb3+. The fluorescence properties and spectroscopic properties of the terbium polypropenic-acid were investigated by excitation spectrum, emission spectrum, IR, far-IR, and Raman spectrum.

  5. Epitaxial ternary nitride thin films prepared by a chemical solution method

    SciTech Connect

    Luo, Hongmei; Feldmann, David M; Wang, Haiyan; Bi, Zhenxing

    2008-01-01

    It is indispensable to use thin films for many technological applications. This is the first report of epitaxial growth of ternary nitride AMN2 films. Epitaxial tetragonal SrTiN2 films have been successfully prepared by a chemical solution approach, polymer-assisted deposition. The structural, electrical, and optical properties of the films are also investigated.

  6. Chemical preparation of powders and films for high temperature superconductors

    NASA Astrophysics Data System (ADS)

    Bunker, B. C.; Voigt, J. A.; Lamppa, D. L.; Doughty, D. H.; Venturini, E. L.; Kwak, J. F.; Ginley, D. S.; Headley, T. J.; Harrington, M. S.; Eatough, M. O.

    A precipitation process has been developed to prepare precursor powders which can be calcined and sintered to form high critical temperature superconductors such as YBa(sub 2)Cu(sub 3)O(sub 7-x). Precursor powders are prepared using a continuous precipitation system in which a solution containing highly soluble salts of the desired metal cations is rapidly and completely mixed with a solution containing precipitating anions such as hydroxide and carbonate ions. The resulting amorphous powder can be calcined to form submicron particles of desired superconducting phases which are useful in preparing inks for the ink-jet printing of superconducting interconnects. The powders can be redissolved in organic solvents to form solutions which can be used in spin or dip coating substrates with thin superconducting films. Finally, the powders have been used to prepare bulk ceramics which exhibit the highest reported critical currents of any chem-prep ceramics. Bulk samples prepared from chloride doped precursors exhibit large, oriented grains and extensive flux pinning.

  7. Optical properties of amorphous Se films prepared by PECVD

    NASA Astrophysics Data System (ADS)

    Nagels, P.; Sleeckx, E.; Callaerts, R.; Márquez, E.; González, J. M.; Bernal-Oliva, A. M.

    1997-05-01

    The optical transmission spectrum of amorphous Se films prepared by plasma-enhanced chemical vapour deposition was measured over the 500 to 2000 nm spectral region. The absorption coefficient values plotted vs photon energy according to Tauc's law yielded an optical gap, Eg, of 1.94 eV. The temperature dependence of Eg was measured between 13 K and 300 K and was found to be well described within Fan's one-phonon approximation. Photo-induced darkening of the optical gap was studied by illumination at 13 K and 77 K.

  8. Hard three-dimensional sp 2 carbon-bonded phase formed by ion beam irradiation of fullerene, a-C and polymeric a-C:H films

    NASA Astrophysics Data System (ADS)

    Baptista, D. L.; Foerster, C. E.; Lepienski, C. M.; Zawislak, F. C.

    2004-06-01

    The formation of new carbon amorphous phase through the ion irradiation of fullerene, a-C and polymeric a-C:H films is presented. The carbon films were subjected to N irradiation at 400 keV in the fluence range from 10 13 to 3 × 10 16 N cm -2. Modifications in the carbon structure, as function of the irradiation fluence, were investigated using the Rutherford backscattering spectrometry, nuclear reaction analysis, Fourier transform infrared, Raman spectroscopy, UV-VIS-NearIR spectrophotometry and nanoindentation techniques. After high fluence, the three carbon samples were transformed into very similar hard (≈14 GPa) and non-hydrogenated amorphous carbon layers with very low optical gaps (≈0.2 eV) and an unusual sp 2 rich-bonded atomic network. The mechanical properties of the irradiated films correlated with the bonding topologies of this new sp 2 carbon phase are analyzed in terms of the constraint-counting model. The results show that the unusual rigidity was achieved by the distortion of the sp 2 carbon bond angles, giving origin to a constrained three-dimensional sp 2 carbon bonded network.

  9. Preparation of a cDNA library from the hagfish slime gland

    SciTech Connect

    Gadbois, D.M.; Salo, W.L.; Ann, D.K.; Downing, S.W.; Carlson, D.M.

    1986-05-01

    The slime glands of hagfish have two major cell types, gland thread cells (GTCs) and gland mucous cells (GMCs), both of which upon contact with water contribute to an abundant viscous mucus. GTCs are unique specialized cells in which 60-80% of the mature GTC volume is occupied by a single tapered thread about 60 cm long formed by bundling keratin intermediate filaments (IFs). Each IF is composed of three 63.5 kD protein subunits (..cap alpha.., ..beta.., ..gamma..). Poly (A/sup +/) mRNA was isolated from GTCs and translated by the rabbit reticulocyte system with (/sup 35/S) Met. Analysis of the translation products showed a major labeled protein at 65 kD. A cDNA library prepared from the poly (A/sup +/) mRNAs was screened with /sup 32/P-labeled IF probes from human epidermis. Several clones containing cross-hybridizing inserts were identified.

  10. Preparation and Characterization of Ultrathin Films and Film Coatings for Microelectronics

    NASA Astrophysics Data System (ADS)

    Pogoryelov, Y. A.

    2004-06-01

    The work is devoted to the preparation and characterization of new thin metal film media for various types of non-volatile memories, and also to the development of new techniques for characterization of film parameters in microelectronics. We studied the physics of indirect exchange coupling in trilayer thin-film structures based on rear earth (Tb) and transition metals (Fe) with the nonmagnetic spacer (Au), which were prepared by electron-beam evaporation in an ultrahigh vacuum system. Investigations were carried out using magneto-optical and magneto-transport techniques, including know-how based on the Hall-like effect at zero applied external magnetic field. Oscillations of the Hall resistivity with the change of its sign, typical for the Ruderman-Kittel-Kasuya-Yosida model of exchange interactions, were experimentally observed. Also, a new method is presented for determining thermophysical parameters. It can be applied for non-contact and non-destructive investigation and monitoring of the adhesion of coatings or films to the substrate, both during and after deposition.

  11. Influence of the source gas ratio on the hydrogen and deuterium content of a-C:H and a-C:D films: Plasma-enhanced CVD with CH4/H2, CH4/D2, CD4/H2 and CD4/D2

    NASA Astrophysics Data System (ADS)

    Ozeki, K.; Sekiba, D.; Suzuki, T.; Kanda, K.; Niibe, M.; Hirakuri, K. K.; Masuzawa, T.

    2013-01-01

    Amorphous hydrogenated carbon (a-C:H) and amorphous deuterated carbon (a-C:D) films were prepared using plasma-enhanced chemical vapor deposition (PECVD) from CD4, H2, CD4 and D2 source gases. Fourteen different samples were prepared by changing the source gas ratios of CH4/H2, CH4/D2, CD4/H2, and CD4/D2. The concentrations of hydrogen (H) and deuterium (D) relative to carbon (C) in the films were determined by elastic recoil detection analysis (ERDA) and Rutherford backscattering spectroscopy (RBS). The sp2/(sp2 + sp3) ratios of the films were analyzed by near-edge X-ray absorption fine structure (NEXAFS) measurements. Hardness and mass density of the films were measured using a nanoindenter and X-ray reflectivity (XRR), respectively. For all combinations of source gas, the H and D concentrations varied by only 4.0 at.%. For the CH4/D2 source gas, the D concentration in the film increased from 0 at.% with the D2/(CH4 + D2) source gas combination to 11.2 at.% for the 80% D2/(CH4 + D2) source gas combination. The increase in D concentration exceeded the increase in total H and D concentration (3.4 at.%). For CH4/D2 source gas, the H concentration decreased as the D concentration increased. For the CD4/H2 source gas, we observed the opposite tendency. Additionally, an isotope effect between the a-C:H films and the a-C:D films was observed, with preferential incorporation of H over D. From the NEXAFS measurements, the sp2/(sp2 + sp3) ratios in all of the samples were between 38.8% and 40.8%. A correlation between the sp2/(sp2 + sp3) ratio and the H2 or D2 gas source ratio was not observed. The hardness and density of the films decreased when the H2 or D2 source gas ratio increased. Even though the H concentration in the a-C:H films was higher than the D concentration in the a-C:D films, the a-C:D films had lower hardness and mass density values. These findings suggest that information concerning the voids, nanostructures, sp2/sp3 ratios and H concentrations of

  12. Electrophoretic deposition onto an insulator for thin film preparation toward electronic device fabrication

    NASA Astrophysics Data System (ADS)

    Miyajima, Shougo; Nagamatsu, Shuichi; Pandey, Shyam S.; Hayase, Shuzi; Kaneto, Keiichi; Takashima, Wataru

    2012-11-01

    An electrostatic film fabrication method utilizing the dielectric layer, entitled dielectric barrier electrophoretic deposition (DBEPD) has been proposed. We demonstrated the fabrication of uniform organic semiconductor thin film onto any kind of substrate by DBEPD. Optical absorption spectra of colloidal poly(3-hexylthiophene) (P3HT) film prepared by DBEPD exhibited the clear vibrational structure attributed to highly ordered domains. It was in contrast to the relatively disordered structure as shown in the case of P3HT film prepared by conventional electrophoretic deposition (EPD). Organic field effect transistors fabricated by each method showed similar organic field effect transistor characteristics, however, the uniformity of DBEPD film was superior to EPD film.

  13. Preparation of films of a highly aligned lipid cubic phase.

    PubMed

    Squires, Adam M; Hallett, James E; Beddoes, Charlotte M; Plivelic, Tomás S; Seddon, Annela M

    2013-02-12

    We demonstrate a method by which we can produce an oriented film of an inverse bicontinuous cubic phase (Q(II)(D)) formed by the lipid monoolein (MO). By starting with the lipid as a disordered precursor (the L(3) phase) in the presence of butanediol, we can obtain a film of the Q(II)(D) phase showing a high degree of in-plane orientation by controlled dilution of the sample under shear within a linear flow cell. We demonstrate that the direction of orientation of the film is different from that found in the oriented bulk material that we have reported previously; therefore, we can now reproducibly form Q(II)(D) samples oriented with either the [110] or the [100] axis aligned in the flow direction depending on the method of preparation. The deposition of MO as a film, via a moving fluid-air interface that leaves a coating of MO in the L(3) phase on the capillary wall, leads to a sample in the [110] orientation. This contrasts with the bulk material that we have previously demonstrated to be oriented in the [100] direction, arising from flow producing an oriented bulk slug of material within the capillary tube. The bulk sample contains significant amounts of residual butanediol, which can be estimated from the lattice parameter of the Q(II)(D) phase obtained. The sample orientation and lattice parameters are determined from synchrotron small-angle X-ray scattering patterns and confirmed by simulations. This has potential applications in the production of template materials and the growth of protein crystals for crystallography as well as deepening our understanding of the mechanisms underlying the behavior of lyotropic liquid-crystal phases.

  14. Electrical properties of fluorinated amorphous carbon (a-C:F(x)) and aluminum nitride (AlN) films

    NASA Astrophysics Data System (ADS)

    Biswas, Nivedita

    Electrical properties of Fluorinated Amorphous Carbon (a-C:Fx) and Aluminum Nitride (AlN) films were studied using capacitance-voltage (C-V), conductance-voltage (G-V) and current-voltage (I-V) measurements. The films were deposited using Plasma Enhanced Chemical Vapor Deposition (PECVD) technique under different conditions. The C-V characteristics of the a-C:Fx, films was stretched about the voltage axis, exhibited hysteresis effects and was characterized with a frequency dependent flatband voltage. The equivalent parallel conductance data showed a good fit to theory only if continuum of states is assumed. I-V characteristics exhibited low current in the forward and reverse biasing conditions. Annealing the sample in hydrogen introduced charge leakage in the film and was characterized with a damaged interface. The C-V characteristics of the AlN films were marked with frequency dependent flatband voltage and exhibited minimal hysteresis. Depending on processing conditions, equivalent parallel conductance data showed a good fit to theory either for single time constant or continuum of states model. I-V characteristics indicated that the current conduction in these films is a bulk limited process. Dielectric constant, as calculated using C-V curves and using I-V curves, showed good agreement. Annealing the samples in hydrogen resulted in charge polarization and reversal of hysteresis cycle but the interfacial characteristics showed marked improvement.

  15. Thin-film preparation by back-surface irradiation pulsed laser deposition using metal powder targets

    NASA Astrophysics Data System (ADS)

    Kawasaki, Hiroharu; Ohshima, Tamiko; Yagyu, Yoshihito; Ihara, Takeshi; Yamauchi, Makiko; Suda, Yoshiaki

    2017-01-01

    Several kinds of functional thin films were deposited using a new thin-film preparation method named the back-surface irradiation pulsed laser deposition (BIPLD) method. In this BIPLD method, powder targets were used as the film source placed on a transparent target holder, and then a visible-wavelength pulsed laser was irradiated from the holder side to the substrate. Using this new method, titanium oxide and boron nitride thin films were deposited on the silicon substrate. Surface scanning electron microscopy (SEM) images suggest that all of the thin films were deposited on the substrate with some large droplets irrespective of the kind of target used. The deposition rate of the films prepared by using this method was calculated from film thickness and deposition time to be much lower than that of the films prepared by conventional PLD. X-ray diffraction (XRD) measurement results suggest that rutile and anatase TiO2 crystal peaks were formed for the films prepared using the TiO2 rutile powder target. Crystal peaks of hexagonal boron nitride were observed for the films prepared using the boron nitride powder target. The crystallinity of the prepared films was changed by annealing after deposition.

  16. Preparation of TiO2 thin films using octadecylamine Langmuir-Blodgett films and evaluation of their photocatalytic activity.

    PubMed

    Takahashi, Masashi; Sendoh, Mitsuyuki; Kobayashi, Koichi; Tajima, Kazuo

    2011-01-01

    A study was conducted to demonstrate that nanometer-thick titanium dioxide (TiO(2)) thin films could be prepared by the hydrolysis of titanium potassium oxalate using octadecylamine (ODA) Langmuir-Blodgett (LB) films as templates. The amount of TiO(2) generated in the LB film was found to be proportional to the number of deposited ODA layers, which enables precise control of the TiO(2) film thickness. After heat treatment of the LB films at 300-600°C, the photocatalytic activities of the resulting TiO(2) films were determined from the decomposition of stearic acid cast films when irradiated with UV light for different time periods. Higher photocatalytic activity was observed in TiO(2) films heat treated at lower temperatures.

  17. Preparation and characterisation of novel thick sol-gel titania film photocatalysts.

    PubMed

    Mills, Andrew; Elliott, Nicholas; Hill, George; Fallis, David; Durrant, James R; Willis, Richard L

    2003-05-01

    The preparation and characterization of thick (9 microns), clear, mechanically robust and photocatalytically active films of nanocrystalline anatase titania are described. XRD and SEM analysis show the films comprise 13 nm particles of anatase TiO2. Thin (54 nm) films of the 'paste' TiO2, along with sol-gel titania films made by a more traditional route are also prepared and characterised. All titania films mediate the photocatalytic destruction of stearic acid with a quantum yield of 0.0016 +/- 0.0003, using either 365 nm (i.e. BLB) or 254 nm (germicidal) light. P25 TiO2 films also appear to mediate the same process with a similar formal quantum efficiency. Of all the films tested, the thick paste TiO2 films are the most ideally suited for use with near UV light, for reasons which are discussed. All the titania films tested exhibit photoinduced superhydrophilicity.

  18. Preparation of a biocompatible magnetic film from an aqueous ferrofluid

    NASA Astrophysics Data System (ADS)

    Albornoz, Cecilia; Jacobo, Silvia E.

    2006-10-01

    Very promising nanoparticles for biomedical applications or in medical drug targeting are superparamagnetic nanoparticles based on a core consisting of iron oxides (SPION) that can be targeted through external magnets. Polyvinyl alcohol (PVA) is a unique synthetic biocompatible polymer that can be chemically cross-linked to form a gel. Biotechnology applications of magnetic gels include biosensors, targeted drug delivery, artificial muscles and magnetic buckles. These gels are produced by incorporating magnetic materials in the polymer composites. In this paper we report the synthesis of an aqueous ferrofluid and the preparation of a biocompatible magnetic gel with polyvinyl alcohol and glutharaldehyde (GTA). HClO 4 was used to induce the peptization since this kind of ferrofluid does not have surfactant. The magnetic gel was dried to generate a biocompatible film.

  19. Stretchable and Conductive Polymer Films Prepared by Solution Blending.

    PubMed

    Li, Pengcheng; Sun, Kuan; Ouyang, Jianyong

    2015-08-26

    Stretchable and conductive materials can have important application in many areas, such as wearable electronics and healthcare devices. Conducting polymers have very limited elasticity because of their rigid conjugated backbone. In this work, highly stretchable and conductive polymer films are prepared by coating or casting aqueous solution of poly(3,4-ethylenedioxythiophene):polystyrenesulfonate ( PSS) and a soft polymer, including poly(ethylene glycol), poly(ethylene oxide), or poly(vinyl alcohol). The soft polymers can greatly improve the stretchability and the conductivity of PSS. The elongation at break can be increased from 2% up to 55%. The soft polymers can also enhance the conductivity of PSS from 0.2 up to 75 S cm(-1). The conductivity is further enhanced by adding dimethyl sulfoxide (DMSO) or ethylene glycol (EG) into the aqueous solutions of the polymer blends. Polymer blends with an elongation at break of close to 50% and a conductivity of 172 S cm(-1) are attained.

  20. Preparation and magnetoresistance of silver and copper chalcogenide thin films

    NASA Astrophysics Data System (ADS)

    Chuprakov, Ilya; Watts, Steven; Wirth, Steffen; von Molnár, Stephan; Dahmen, Klaus-Hermann

    1998-03-01

    An unexpected giant positive magnetoresitance was recently discovered in non-stoichiometric crystals of Ag_2Te and Ag_2Se [1]. There, a linear magnetoresistance effect as high as 120% was observed in fields of 4 T at room temperature. Here we report on thin films of copper and silver chalcogenides prepared by a vapor phase transport method. A prefered grain orientation is found in the films after annealing. Resistance, magnetoresistance and Hall effect were measured. Typically, the resistivity is temperature independent below 70 K with a value of 1 mΩ cm. As in the crystals, there is a large positive magnetoresistance, but the field dependence is non-linear with a typical value of 50% at room temperature and 200% at temperatures below 100 K for applied fields of 6 T. Variations of the deposition techniques are explored in order to establish the relationship between the deposition conditions and transport properties. [0.25cm] [1] R. Xu, A. Husmann, T.F. Rosenbaum, M.-L. Saboungi, E.J. Enderby and P.B. Littlewood, Nature 390, 57 (1997).

  1. Characterization of film-forming solutions and films incorporating free and nanoencapsulated tea polyphenol prepared by gelatins with different Bloom values

    USDA-ARS?s Scientific Manuscript database

    Gelatin film-forming solutions and their films incorporating tea polyphenol (TP) and chitosan nanoparticles (CSNs) were prepared from gelatins with different Bloom values (100, 150 and 225). Blank gelatin film-forming solutions and films were prepared as controls. Gelatins with higher Bloom values h...

  2. Electroless plating of honeycomb and pincushion polymer films prepared by self-organization.

    PubMed

    Yabu, Hiroshi; Hirai, Yuji; Shimomura, Masatsugu

    2006-11-07

    This report describes the fabrication and electroless plating of regular porous and pincushion-like polymer structures prepared by self-organization. Honeycomb-patterned films were prepared by simple casting of polymer solution under applied humid air and pincushion structures by peeling off the top layer of the former films. Silver-deposited honeycomb-patterned films and pincushion films were obtained by simple electroless plating of the respective original structures. XPS revealed Ag deposition on the honeycomb-patterned film. After thermal decomposition or solvent elution of the template polymer, unique metal mesoscopic structures were obtained.

  3. Composition, XRD and morphology study of laser prepared LiNbO3 films

    NASA Astrophysics Data System (ADS)

    Jelínek, M.; Havránek, V.; Remsa, J.; Kocourek, T.; Vincze, A.; Bruncko, J.; Studnička, V.; Rubešová, K.

    2013-03-01

    LiNbO3 films were deposited by PLD from LiNbO3 crystalline or from three different stoichiometric or Li-enriched LiNbO3 targets. Polycrystalline films were prepared on SiO2/Si or sapphire substrates at temperatures T S ˜650-750 °C. Main attention was paid to the influence of targets preparation and the deposition conditions on films composition, morphology and crystallinity. The thin-film morphology was determined by SEM microscopy. The composition was measured by SIMS, RBS, PIXE and PIGE methods. Highly oriented, smooth and stoichiometric LiNbO3 films were synthesized.

  4. Preparation and Characterization of an Olive Flounder (Paralichthys olivaceus) Skin Gelatin and Polylactic Acid Bilayer Film.

    PubMed

    Lee, Ka-Yeon; Song, Kyung Bin

    2017-03-01

    Olive flounder skin gelatin (OSG) was used as a film base material. A bilayer film of OSG and polylactic acid (PLA) was prepared using solvent casting method to enhance the film properties. Physical properties of the OSG-PLA film were increased compared with the nonaugmented OSG film. In particular, the PLA lamination decreased water vapor permeability from 2.17 to 0.92 × 10(-9) g·m/m(2) ·s·Pa, as well as of the water solubility from 16.62% to 9.27%, in the bilayer film relative to the OSG film. The oxygen permeability of the OSG-PLA bilayer film was held low by the OSG film, compensating for the high oxygen permeability of the PLA layer. Therefore, the OSG-PLA bilayer film with its enhanced physical properties and high water and oxygen barrier properties can be applied as a food packaging material.

  5. Preparation and characterization of collagen/hydroxypropyl methylcellulose (HPMC) blend film.

    PubMed

    Ding, Cuicui; Zhang, Min; Li, Guoying

    2015-03-30

    This study aimed to prepare and characterize the collagen/HPMC blend film (1/1). Thermogravimetric analysis and differential scanning calorimetry were used to investigate the thermal properties of the film. Both thermal decomposition temperature and denaturation temperature of the blend film were higher than those of the collagen film due to the intermolecular hydrogen bonding interaction between collagen and HPMC, which was demonstrated by Fourier transform infrared spectroscopy. Additionally, the morphologies, mechanical properties and hydrophilicity of films were examined. The blend film exhibited a more homogeneous and compact structure compared with that of the collagen film, as observed from scanning electron microscopy and atomic force microscopy. The tensile strength, ultimate elongation and hydrophilicity of the blend film were superior to those of the pure collagen film. Furthermore, the introduction of polyethylene glycol 1500 had almost no influence on the thermal properties of the blend film but obviously improved its stretch-ability and smoothness.

  6. Superhydrophilicity-assisted preparation of transparent and visible light activated N-doped titania film

    NASA Astrophysics Data System (ADS)

    Xu, Qing Chi; Wellia, Diana V.; Amal, Rose; Liao, Dai Wei; Loo, Say Chye Joachim; Tan, Timothy Thatt Yang

    2010-07-01

    A novel and environmental friendly method was developed to prepare transparent, uniform, crack-free and visible light activated nitrogen doped (N-doped) titania thin films without the use of organic Ti precursors and organic solvents. The N-doped titania films were prepared from heating aqueous peroxotitanate thin films deposited uniformly on superhydrophilic uncoated glass substrates. The pure glass substrates were superhydrophilic after being heated at 500 °C for 1 h. Nitrogen concentrations in the titania films were adjusted by changing the amount of ammonia solution. The optimal photocatalytic activity of the N-doped titania films was about 14 times higher than that of a commercial self-cleaning glass under the same visible light illumination. The current reported preparative technique is generally applicable for the preparation of other thin films.

  7. Structure Analyses of Organic Thin Films Prepared by a Plasma Enhanced Vacuum Evaporation

    NASA Astrophysics Data System (ADS)

    Sugimoto, Ryousuke; Osada, Kousuke; Kurata, Masahiko; Matsumoto, Hiroyuki; Iwamori, Satoru; Noda, Kazutoshi

    Organic thin films were prepared with pyromellitic dianhydride (PMDA) and oxydianiline (ODA) by vacuum evaporation with or without argon plasma, and molecular structures and surface morphologies of the PMDA, ODA, polyamic acid (PAA) and polyimide (PI) thin films were analyzed. The surface roughness decreased due to the plasma during the deposition. Oxygen content of the PMDA thin film prepared with the plasma decreased compared to that without the plasma. However, the PMDA thin film prepared with the plasma had a hydrophilic surface compared to that without the plasma. All of these organic thin films prepared with the plasma had hydrophilic surfaces compared to those without the plasma. Surface roughness of these thin films has a smaller effect on the wettability than hydrophilic moieties.

  8. Preparation of Copper (Cu)-Nickel (Ni) Alloy Thin Films for Bilayer Graphene Growth

    DTIC Science & Technology

    2016-02-01

    Laboratory Preparation of Copper (Cu)-Nickel (Ni) Alloy Thin Films for Bilayer Graphene Growth by Andrew Chen and Eugene Zakar Sensors and Electron...COVERED (From - To) June–August 2015 4. TITLE AND SUBTITLE Preparation of Copper (Cu)-Nickel (Ni) Alloy Thin Films for Bilayer Graphene Growth 5a...distribution is unlimited. 13. SUPPLEMENTARY NOTES 14. ABSTRACT Co-sputtered copper (Cu)-nickel (Ni) alloys with layered thin-film ratios of 6

  9. The preparation, processing and properties of thin and thick films for microelectric applications

    NASA Astrophysics Data System (ADS)

    Bagley, B. G.; Greene, L. H.; Barboux, P.; Tarascon, J. M.; Venkatesan, T.

    High-Tc thin and thick films of YBa2Cu2O(7-y) and thick films based on the Bi-Sr-Ca-Cu and Tl-Ba-Ca-Cu systems were prepared and their properties investigated. It was found that YB2Cu3O(7-y) thin films prepared at temperatures up to 400 C, have amorphous structures, and those prepared in the 400-650 C region exhibit polyphase microstructure, due to the rapid crystallization kinetics of the competing phases. Methods for bipassing the 'forbidden' temperature region are described. Preparation of YBa2Cu2O(7-y) thick films was achieved via an aqueous sol-gel technique. Bi-Sr-Ca-Cu- and Tl-Ba-Ca-Cu-based thick films were prepared via the decomposition of glycerol-based solutions containing nitrates of the elements.

  10. Preparation of mixed metal thin films by a PVD method using several kinds of powder targets

    NASA Astrophysics Data System (ADS)

    Suda, Yoshiaki; Kawasaki, Hiroharu; Ohshima, Tamiko; Yagyu, Yoshihito; Ihara, Takeshi; Yamauchi, Makiko; Plasma process; application Team

    2015-09-01

    Bismuth iron garnet (Bi3Fe5O12) and aluminum doped zinc oxide (AZO) thin films were prepared by a physical vapor deposition method using mixed metal powder targets. The X-ray powder diffraction and X-ray photoelectron spectroscopy results suggest that crystalline thin films can be prepared using powder targets with quality similar to that of the films prepared using bulk targets. Bi3Fe5O12 films prepared using the pulsed laser deposition method were Bi rich, which may be due to the lower melting temperature of Bi (544 K) compared with that of Fe (1811 K). The mean transparency and resistivity of the AZO films prepared by the sputtering method were approximately 79%-84% and 0.5 - 1.4 ohm/cm, respectively.

  11. Preparation and adsorption properties of nano magnetite chitosan films for heavy metal ions from aqueous solution

    SciTech Connect

    Lasheen, M.R.; El-Sherif, Iman Y.; Tawfik, Magda E.; El-Wakeel, S.T.; El-Shahat, M.F.

    2016-08-15

    Highlights: • Nano magnetite–chitosan films were prepared by casting method. • The efficiency of the prepared films for removing heavy metals was investigated. • The adsorption mechanism was studied using different isotherm and kinetic models. • Films reuse and metals recovery were studied. - Abstract: Nano magnetite chitosan (NMag–CS) film was prepared and characterized with different analytical methods. X-ray diffraction (XRD) patterns confirmed the formation of a pure magnetite structure and NMag–CS nanocomposite. TEM image of the film, revealed the uniform dispersion of magnetite nanoparticles inside chitosan matrix. The adsorption properties of the prepared film for copper, lead, cadmium, chromium and nickel metal ions were evaluated. Different factors affecting the uptake behavior by the composite films such as time, initial pH and film dose were investigated. The adsorption equilibrium attained using 2 g/L of the film after 120 min of reaction. The equilibrium data were analyzed using Langmuir and Freundlich models. The adsorption kinetics followed the mechanism of the pseudo-second-order equation for all metals. The metals regenerated from films with an efficiency greater than 95% using 0.1 M ethylene diamine tetra acetic acid (EDTA) and films were successfully reused for adsorption.

  12. Electrochemical preparation of poly(methylene blue)/graphene nanocomposite thin films

    SciTech Connect

    Erçarıkcı, Elif; Dağcı, Kader; Topçu, Ezgi; Alanyalıoğlu, Murat

    2014-07-01

    Highlights: • Poly(MB)/graphene thin films are prepared by a simple electrochemical approach. • Graphene layers in the film show a broad band in visible region of absorbance spectra. • Morphology of composite films indicates both disordered and ordered regions. • XRD reveals that nanocomposite films include rGO layers after electropolymerization process. • Chemically prepared graphene is better than electrochemically prepared graphene for electrooxidation of nitrite. - Abstract: Poly(methylene blue)/graphene nanocomposite thin films were prepared by electropolymerization of methylene blue in the presence of graphene which have been synthesized by two different methods of a chemical oxidation process and an electrochemical approach. Synthesized nanocomposite thin films were characterized by using cyclic voltammetry, UV–vis. absorption spectroscopy, powder X-ray diffraction, and scanning tunneling microscopy techniques. Electrocatalytical properties of prepared poly(methylene blue)/graphene nanocomposite films were compared toward electrochemical oxidation of nitrite. Under optimized conditions, electrocatalytical effect of nanocomposite films of chemically prepared graphene through electrochemical oxidation of nitrite was better than that of electrochemically prepared graphene.

  13. Preparation of mesoporous silica thin films by photocalcination method and their adsorption abilities for various proteins.

    PubMed

    Kato, Katsuya; Nakamura, Hitomi; Yamauchi, Yoshihiro; Nakanishi, Kazuma; Tomita, Masahiro

    2014-07-01

    Mesoporous silica (MPS) thin film biosensor platforms were established. MPS thin films were prepared from tetraethoxysilane (TEOS) via using sol-gel and spin-coating methods using a poly-(ethylene oxide)-block-poly-(propylene oxide)-block-poly-(ethylene oxide) triblock polymer, such as P123 ((EO)20(PO)70(EO)20) or F127 ((EO)106(PO)70(EO)106), as the structure-directing agent. The MPS thin film prepared using P123 as the mesoporous template and treated via vacuum ultraviolet (VUV) irradiation to remove the triblock copolymer had a more uniform pore array than that of the corresponding film prepared via thermal treatment. Protein adsorption and enzyme-linked immunosorbent assay (ELISA) on the synthesized MPS thin films were also investigated. VUV-irradiated MPS thin films adsorbed a smaller quantity of protein A than the thermally treated films; however, the human immunoglobulin G (IgG) binding efficiency was higher on the former. In addition, protein A-IgG specific binding on MPS thin films was achieved without using a blocking reagent; i.e., nonspecific adsorption was inhibited by the uniform pore arrays of the films. Furthermore, VUV-irradiated MPS thin films exhibited high sensitivity for ELISA testing, and cytochrome c adsorbed on the MPS thin films exhibited high catalytic activity and recyclability. These results suggest that MPS thin films are attractive platforms for the development of novel biosensors.

  14. Chromium-modified a-C films with advanced structural, mechanical and corrosive-resistant characteristics

    NASA Astrophysics Data System (ADS)

    Ming, Miao Yi; Jiang, Xiaohong; Piliptsou, D. G.; Zhuang, Yuzhao; Rogachev, A. V.; Rudenkov, A. S.; Balmakou, A.

    2016-08-01

    To improve structural, mechanical and chemical properties of diamond-like carbon films, we developed amorphous carbon chromium-modified composite films fabricated by means of cathode magnetic filtered arc deposition. The properties were analyzed by Raman spectroscopy, X-ray photoelectron spectroscopy and atomic force microscopy for the purpose of the structure characterization, elemental analysis and topology examination. Moreover, we also assessed residual stress, the coefficient of friction, hardness, the elastic modulus and corrosion parameters through X-ray double-crystal surface profilometry, tribo-testing, nanoindenter-testing, as well as contact angle measurements and potentiodynamic polarization analysis. As a result of a comparative analysis, we revealed a substantial improvement in the characteristics of developed composite films in comparison with amorphous carbon films. For example, Cr-modification is resulted, in greater integrated performance, toughness and corrosion resistance; the residual stress was reduced substantially.

  15. Preparation and Properties of Silver Nanowire-Based Transparent Conductive Composite Films

    NASA Astrophysics Data System (ADS)

    Tian, Ji-Li; Zhang, Hua-Yu; Wang, Hai-Jun

    2016-06-01

    Silver nanowire-based transparent conductive composite films with different structures were successfully prepared using various methods, including liquid polyol, magnetron sputtering and spin coating. The experimental results revealed that the optical transmittance of all different structural composite films decreased slightly (1-3%) compared to pure films. However, the electrical conductivity of all composite films had a great improvement. Under the condition that the optical transmittance was greater than 78% over the wavelength range of 400-800 nm, the AgNW/PVA/AgNW film became a conductor, while the AZO/AgNW/AZO film and the ITO/AgNW/ITO film showed 88.9% and 94% reductions, respectively, for the sheet resistance compared with pure films. In addition, applying a suitable mechanical pressure can improve the conductivity of AgNW-based composite films.

  16. Comparative investigations on different polymers for the preparation of fast-dissolving oral films.

    PubMed

    Garsuch, Verena; Breitkreutz, Jörg

    2010-04-01

    The aim was to compare different film-forming materials used for the preparation of fast-dissolving oral films. Films were prepared with and without caffeine and caffeine citrate as model drugs. The disintegration/dissolution behaviour of films was investigated using the newly developed slide frame method and Petri dish method. Films were also characterised by dynamic vapour sorption. All films dissolved within 40 s. Drug-loaded films disintegrated more slowly than the equivalent drug-free formulations. Disintegration/dissolution was fastest with films made from the carboxymethyl cellulose C 30 PA 09 (drug-free < 5 s, drug-loaded < 10 s). Dissolution times for drug-loaded oral films made from C 30 PA 09 and HM 6 PA 2910 (hydroxypropyl methyl cellulose) differed significantly (alpha= 0.05). Dynamic vapour sorption studies revealed higher water absorption ratios for carboxymethyl cellulose films, and these were sticky and difficult to handle. This case study showed that hydroxypropyl methyl cellulose was the most suitable film-forming material for drug-free and caffeine-loaded films, providing fast dissolution films that were not sticky and were easy to handle.

  17. Preparation of a Functionally Graded Fluoropolymer Thin Film and Its Application to Antireflective Coating

    NASA Astrophysics Data System (ADS)

    Senda, Kazuo; Matsuda, Tsuyoshi; Kawanishi, Takumi; Tanaka, Kuniaki; Usui, Hiroaki

    2013-05-01

    Fluoropolymer thin films were prepared by the ion-assisted vapor deposition polymerization (IAD) of 2-(perfluorohexyl) ethylacrylate (Rf-6) under Ar ion irradiation. The ion acceleration voltage Va largely affected the film characteristics. With increasing Va, the adhesion strength between the film and the substrate improved, while the surface energy and the refractive index increased. To attain a high adhesion strength, a low surface energy, and a low optical reflectivity simultaneously, a functionally graded film was prepared by varying Va from 300 to 0 V continually in the course of film growth. As a consequence, an antireflective coating with good adhesion and low surface energy was obtained. The optical reflectivity of a glass substrate was reduced from 4.9 to 0.55% at a wavelength of 400 nm by depositing a 100-nm-thick single-layer functionally graded fluoropolymer film. The surface energy of this film was 8.5 mJ/m2.

  18. Thin casein films as prepared by spin-coating: influence of film thickness and of pH.

    PubMed

    Müller-Buschbaum, P; Gebhardt, R; Maurer, E; Bauer, E; Gehrke, R; Doster, W

    2006-06-01

    Casein films were successfully prepared with the spin-coating technique of aqueous casein solutions on base-treated glass surfaces. The film structure is investigated in real space with optical microscopy and atomic force microscopy and for the first time in reciprocal space with grazing incidence small-angle X-ray scattering (GISAXS). The size of the substructures detected in the film increases with pH from 170 nm (pH 5.1) up to 490 nm (pH 9.4). Dynamic light scattering experiments reveal that the average diameters of casein micelles in solution exhibit the same quantitative increase. This result suggests that the substructures detected in the bulklike films with GISAXS reflect intact casein micelles. However, with thin homogeneous casein films, the micelle size diminishes with decreasing film thickness. This indicates that the moderate pressures introduced by spin-coating force the micelles to rearrange into a more compact structure.

  19. Photoactive composite films prepared from mixtures of polystyrene microgel dispersions and poly(3-hexylthiophene) solutions.

    PubMed

    Chen, Mu; Cui, Zhengxing; Edmondson, Steve; Hodson, Nigel; Zhou, Mi; Yan, Junfeng; O'Brien, Paul; Saunders, Brian R

    2015-11-14

    Whilst polystyrene microgels belong to the oldest family of microgel particles, their behaviours when deposited onto substrates or prepared as composites have received little attention. Because polystyrene microgels are solvent-swellable, and inherently colloidally stable, they are well suited to form composites with conjugated polymers. Here, we investigate the morphology and light absorption properties of spin coated composite films prepared from mixed dispersions of polystyrene microgels and poly(3-hexylthiophene) (P3HT) for the first time. We compare the morphologies of the composite films to spin coated microgel films. The films were studied using optical microscopy, SEM, AFM, wide-angle X-ray diffraction and UV-visible spectroscopy. The films contained flattened microgel particles with an aspect ratio of ∼10. Microgel islands containing hexagonally close packed particles were evident for both the pure microgel and microgel/P3HT composite films. The latter were electrically conducting. The composite film morphology was dependent on the microgel and P3HT concentration used for film preparation and a morphology phase diagram was constructed. The P3HT phase acted as an electrically conducting cement and increased the robustness of the films to solvent washing. The composite films were photoactive due to the P3HT component. The absorbance for the films was tuneable and increased linearly with both microgel and P3HT concentration. The results of the study should apply to other organic swellable microgel/conjugated polymer combinations and may lead to new colloidal composites for future optoelectronic applications.

  20. Preparation of cuxinygazsen precursor films and powders by electroless deposition

    DOEpatents

    Bhattacharya, Raghu N.; Batchelor, Wendi Kay; Wiesner, Holm; Ramanathan, Kannan; Noufi, Rommel

    1999-01-01

    A method for electroless deposition of Cu.sub.x In.sub.y Ga.sub.z Se.sub.n (x=0-2, y=0-2, z=0-2, n=0-3) precursor films and powders onto a metallic substrate comprising: preparing an aqueous bath solution of compounds selected from the group consisting of: I) a copper compound, a selenium compound, an indium compound and gallium compound; II) a copper compound, a selenium compound and an indium compound; III) a selenium compound, and indium compound and a gallium compound; IV) a selenium compound and a indium compound; and V) a copper compound and selenium compound; each compound being present in sufficient quantity to react with each other to produce Cu.sub.x In.sub.y Ga.sub.z Se.sub.n (x=0-2, y=0-2, z=0-2, n=0-3); adjusting the pH of the aqueous bath solution to an acidic value by the addition of a dilute acid; and initiating an electroless reaction with an oxidizing counterelectrode for a sufficient time to cause a deposit of Cu.sub.x In.sub.y Ga.sub.z Se.sub.n (x=0-2, y=0-2, z=0-2, n=0-3) from the aqueous bath solution onto a metallic substrate.

  1. Preparation of [100] oriented SrTiO3 thin films on flexible polymer sheets

    NASA Astrophysics Data System (ADS)

    Nishikawa, Hiroaki; Morita, Yusuke; Kusunoki, Masanobu; Hontsu, Shigeki; Tanaka, Hidekazu; Endo, Tamio

    2014-01-01

    In this study, we prepared a uniaxially oriented oxide on a flexible polymer substrate. We first grew [100] oriented SrTiO3 (STO) on a MgO(100) substrate. After bonding the STO film to a poly(ethylene naphthalete) (PEN) sheet with a photoresist, we etched the MgO substrate with a phosphoric acid solution to transfer the oxide film to the PEN sheet. The thin (300 nm) STO films did not crack after release, even after bending the sheet around a rod with a 1 cm radius, while the thicker (800 nm) films did. Ultimately, this process could be adapted to prepare a flexible epitaxial oxide.

  2. Preparation of silica thin films by novel wet process and study of their optical properties.

    PubMed

    Im, Sang-Hyeok; Kim, Nam-Jin; Kim, Dong-Hwan; Hwang, Cha-Won; Yoon, Duck-Ki; Ryu, Bong-Ki

    2012-02-01

    Silicon dioxide (SiO2) thin films have gained considerable attention because of their various industrial applications. For example, SiO2 thin films are used in superhydrophilic self-cleaning surface glass, UV protection films, anti-reflection coatings, and insulating materials. Recently, many processes such as vacuum evaporation, sputtering, chemical vapor deposition, and spin coating have been widely applied to prepare thin films of functionally graded materials. However, these processes suffer from several engineering problems. For example, a special apparatus is required for the deposition of films, and conventional wet processes are not suitable for coating the surfaces of substrates with a large surface area and complex morphology. In this study, we investigated the film morphology and optical properties of SiO2 films prepared by a novel technique, namely, liquid phase deposition (LPD). Images of the SiO2 films were obtained by scanning electron microscopy (SEM) and atomic force microscopy (AFM) in order to study the surface morphology of these films: these images indicate that films deposited with different reaction times were uniform and dense and were composed of pure silica. Optical properties such as refractive index and transmittance were estimated by UV-vis spectroscopy and ellipsometry. SiO2 films with porous structures at the nanometer scale (100-250 nm) were successfully produced by LPD. The deposited film had excellent transmittance in the visible wavelength region.

  3. Preparation of Amorphous Carbon Films and Evaluation of Its Optical Properties and Gas Barrier Property

    NASA Astrophysics Data System (ADS)

    Ohsone, Yuuki; Nishi, Hidetaka; Saito, Masanori; Suzuki, Masaki; Murakami, Hiroya; Ohtake, Naoto

    Hydrogenerated amorphous carbon (a-C:H) films can improve oxygen gas barrier characteristics of plastic food containers, by coating it on the surfaces of such containers, and is intended to enhance the preservative quality. However, it has a problem that the degradation of optical transparency in the visible light range blocks the view of the inner content. In this study, we aimed to reduce the oxygen transmission rate (OTR) as well as to improve optical transparency, and fabricated a-C:H films by the pulse plasma chemical vapor deposition (CVD) method on polyethylene terephthalate (PET) films. First, it is clarified that the gas barrier performance in the a-C:H film in the vicinity of the PET boundary surface was lower than that of bulk a-C:H film. Secondly, the OTR and optical transparency of a-C:H films deposited not only from C2H2 but also from Si(CH3)4 were investigated in detail. The a-C:H film deposited from Si(CH3)4 shows high transmittance of 87% for visible light with a relatively low OTR of 3.2 cc/(m2·atm·day).

  4. SERS activity studies of Ag/Au bimetallic films prepared by galvanic replacement.

    PubMed

    Wang, Chaonan; Fang, Jinghuai; Jin, Yonglong

    2012-10-01

    Ag films on Si substrates were fabricated by immersion plating, which served as sacrificial materials for preparation of Ag/Au bimetallic films by galvanic replacement method. SEM images displayed that the sacrificial Ag films presenting island morphology experienced interesting structural evolution process during galvanic replacement reaction, and nano-scaled holes were formed in the resultant bimetallic films. SERS measurements using crystal violet as an analyte showed that SERS intensities of bimetallic films were enhanced significantly compared with that of pure Ag films and related mechanisms were discussed. Immersion plating experiment carried out on Ag films on PEN substrates fabricated by photoinduced reduction method further confirmed that galvanic replacement is an easy method to fabricate Ag/Au bimetallic and a potential approach to improve the SERS performance of Ag films.

  5. Preparation and gas sensing properties of novel CdS-supramolecular organogel hybrid films

    NASA Astrophysics Data System (ADS)

    Xia, Huiyun; Peng, Junxia; Liu, Kaiqiang; Li, Chen; Fang, Yu

    2008-05-01

    A novel CdS-supramolecular organogel hybrid film with unusual morphology has been fabricated by exposing a supramolecular organogel film containing Cd(Ac)2 in an H2S atmosphere at room temperature. The organogel film was prepared by spin-coating a LMOG (low-molecular weight organic gelator) gel of dmethyl sulfoxide onto a glass plate substrate. XRD, SEM, EDS, TG-DTA, UV-vis, PL (photoluminescence) spectroscopy and PL lifetime measurements were employed to characterize the film. It was shown that the organogel film had functioned as a template to control the morphology of the final hybrid film. The quantities and sizes of the CdS particles embedded in the organogel films can be easily altered by varying the initial concentration of Cd(Ac)2. Importantly, the PL of the hybrid film is sensitive to the presence of some volatile organic monoamines and diamines. The selectivity and reversibility of the sensing process were investigated.

  6. Preparation and properties of all solid-state electrochromic thermal control thin film

    NASA Astrophysics Data System (ADS)

    He, Yanchun; Xiong, Yuqing; Qiu, Jiawen; Xu, Min; Wang, Jiebing; Wu, Chunhua; Zhao, Yinzhong

    An all solid-state electrochromic thin film was designed to be used on thermal control of spacecraft. The structure of thin film is ITO/WO3/Ta2O5/NiO/Ag/Glass. ITO, WO3, Ta2O5, NiO and Ag thin films were prepared by magnetron sputtering method, and successfully produced all solid-state electrochromic thermal control thin film on substrate glass by magnetron sputtering. The tested properties of the thin film shows the result of 0.381, 0.490.

  7. Group III Impurity Doped Zinc Oxide Thin Films Prepared by RF Magnetron Sputtering

    NASA Astrophysics Data System (ADS)

    Minami, Tadatsugu; Sato, Hirotoshi; Nanto, Hidehito; Takata, Shinzo

    1985-10-01

    The detailed study of electrical properties in group III impurity doped ZnO thin films prepared by rf magnetron sputtering is described. The resistivity is lowered by doping of B, Al, Ga and In into ZnO films. The characteristic features of ZnO films doped with group III elements except for B are their high carrier concentration and low mobility. Variation of the mobility with the impurity content is roughly governed by the ionized impurity scattering. It is shown that the doped ZnO films exhibit the resistivity dependence on film thickness below 300 nm.

  8. Preparation of ordered and crosslinked films from liquid crystalline vinyl ether monomers

    SciTech Connect

    Andersson, H.; Sahlen, F.; Gedde, U.W.; Hult, A.

    1993-12-31

    Highly ordered densely crosslinked liquid crystalline poly(vinyl ether) films have been prepared by in-situ photopolymerization of oriented bifunctional mesogenic vinyl ether monomers. Orientation was achieved either by a simple surface treatment, using an unidirectionally rubbed polyimide film or by a magnetic field. Polymerization from various monomer phases resulted in LC polymer network films with different molecular organizations. The films were analyzed with small-angle X-ray scattering, polarized light microscopy and infrared-dichroism measurements. It was shown that films with nematic, smectic A and smectic B structures were obtained, the latter having a very high degree of orientation.

  9. Influence of process parameters on the preparation of pharmaceutical films by electrostatic powder deposition.

    PubMed

    Prasad, Leena Kumari; LaFountaine, Justin S; Keen, Justin M; Williams, Robert O; McGinity, James W

    2016-12-30

    Electrostatic powder deposition (ESPD) has been developed as a solvent-free method to prepare pharmaceutical films. The aim of this work was to investigate the influence of process parameters during (1) electrostatic powder deposition, (2) curing, and (3) removal of the film from the substrate on the properties of the film. Polyethylene oxide (PEO) was used as the model polymer and stainless steel 316 as the substrate. Deposition efficiency (i.e. deposited weight) was measured with varying charging voltage, gun tip to substrate distance, and environmental humidity. Scanning electron microscopy was utilized to assess film formation, and adhesive and mechanical strength of films were measured with varying cure temperature and time. Adhesive strength was measured for films prepared on substrates of varying surface roughness. When deposition was performed at low humidity conditions, 25%RH, process parameters did not significantly affect deposition behavior. At 40%RH, increasing deposition efficiency with decreasing gun tip to substrate distance and increasing voltage (up to 60kV) was observed. Complete film formation was seen by 30min at 80°C, compared to lower curing temperatures and times. All films were readily removed from the substrates. The results show the ESPD process can be modified to produce films with good mechanical properties (e.g. tensile strength>0.06MPa), suggesting it is a promising dry powder process for preparing pharmaceutical films.

  10. Electrochemical preparation of Photosystem I-polyaniline composite films for biohybrid solar energy conversion.

    PubMed

    Gizzie, Evan A; LeBlanc, Gabriel; Jennings, G Kane; Cliffel, David E

    2015-05-13

    In this work, we report for the first time the entrapment of the biomolecular supercomplex Photosystem I (PSI) within a conductive polymer network of polyaniline via electrochemical copolymerization. Composite polymer-protein films were prepared on gold electrodes through potentiostatic electropolymerization from a single aqueous solution containing both aniline and PSI. This study demonstrates the controllable integration of large membrane proteins into rapidly prepared composite films, the entrapment of such proteins was observed through photoelectrochemical analysis. PSI's unique function as a highly efficient biomolecular photodiode generated a significant enhancement in photocurrent generation for the PSI-loaded polyaniline films, compared to pristine polyaniline films, and dropcast PSI films. A comprehensive study was then performed to separately evaluate film thickness and PSI concentration in the initial polymerization solution and their effects on the net photocurrent of this novel material. The best performing composite films were prepared with 0.1 μM PSI in the polymerization solution and deposited to a film thickness of 185 nm, resulting in an average photocurrent density of 5.7 μA cm(-2) with an efficiency of 0.005%. This photocurrent output represents an enhancement greater than 2-fold over bare polyaniline films and 200-fold over a traditional PSI multilayer film of comparable thickness.

  11. Reactively sputtered titanium carbide thin films: Preparation and properties

    NASA Astrophysics Data System (ADS)

    Eizenberg, M.; Murarka, S. P.

    1983-06-01

    The low resistivity and refractory nature of titanium carbide makes it potentially useful as a diffusion barrier in thin film metallization schemes. In the present investigation, deposition and properties of thin titanium carbide films have been investigated. The films were deposited by reactive radio frequency sputtering in methane-argon mixtures on a variety of substrates. The effects of methane to argon ratio, total sputtering pressure, and power on the film deposition rate, composition and properties were determined. There were interactive effects of these parameters on the composition and properties of these films. Resistivity increased with carbon content; for Ti/C≥1 it was ˜200 μΩ cm. Stress that was compressive was maximum in the nearly stoichiometric TiC film. Grain size was small in all films, especially so in carbon rich films. All stoichiometric titanium carbide films were resistant to HF solutions. Films with TiC/≥1 dissolved easily in ethylene dinitrilo tetra acetric acid (EDTA) solution.

  12. Low-temperature preparation of highly conductive thin films from acrylic acid-stabilized silver nanoparticles prepared through ligand exchange.

    PubMed

    Vo, Duc Quy; Shin, Eun Woo; Kim, Jae-Seong; Kim, Sunwook

    2010-11-16

    The preparation of AcA-stabilized Ag nanoparticles and its application to make highly conductive thin films are reported. The AcA-stabilized Ag nanoparticles were prepared through a ligand exchange of original oleylamine (OLA)-coated Ag nanoparticles with acrylic acid (AcA), which acted as both an antisolvent and a modifying ligand during the ligand exchange process. Efficiencies of the ligand exchange as well as the properties of Ag nanoparticles were analyzed using various techniques including TEM, FT-IR, XPS, TGA, and UV-vis methods. The thin films were fabricated by annealing spin-coated AcA-stabilized Ag nanoparticles. Further, the effects of annealing temperature, time, and film thickness on both the film morphology and electrical conductivity have been investigated. In this work, due to the low boiling temperature of stabilizer (AcA) and adjustment of annealing conditions, high electrical conductivity was obtained for the Ag thin films. For example, when annealing at 175 °C for 30 min, a 70 nm thick film showed a maximum electrical conductivity of 1.12 × 10(5) S cm(-1). A conductive layer on a flexible polymer substrate (e.g., PET) sheet has been successfully prepared by annealing a spin-coated film at 140 °C for 30 min. The combined advantages of long-term stability of the AcA-stabilized Ag nanoparticles, low annealing temperature, and high conductivity of the prepared thin films make this relatively simple method attractive for applications in flexible electronics.

  13. Electroplated Fe films prepared from a deep eutectic solvent

    NASA Astrophysics Data System (ADS)

    Yanai, T.; Shiraishi, K.; Shimokawa, T.; Watanabe, Y.; Ohgai, T.; Nakano, M.; Suzuki, K.; Fukunaga, H.

    2014-05-01

    Electroplating of Fe films was carried out from choline chloride-ethylene glycol types of DES (Deep Eutectic Solvent). We investigated magnetic properties of the plated Fe films and evaluated the productivity for the electroplating process. Consequently, we found that surface morphology and current efficiency of the plated films were affected by the bath temperature. We obtained the Fe films with relatively smooth surface and high current efficiency in the bath temperature range from 70 to 110 °C. The deposition rate for our process depended on the current density, and we obtained high deposition rate value of approximately 120 μm/h. We also obtained high current efficiency values of approximately 90% in the wide range of plating time. These results indicate that the DES-based bath has industrial advantages for mass-producing Fe films. Therefore, we conclude that the DES-based bath is an attractive plating bath for Fe films.

  14. Thin film solid-state lithium batteries prepared by convective vapor-phase processes

    SciTech Connect

    Takehara, Z.; Ogumi, Z.; Uchimoto, Y.; Endo, E. . Faculty of Engineering); Kanamori, Y. )

    1991-06-01

    Thin-film solid-state lithium batteries of total thickness less than 20 {mu}m were prepared. These thin lithium batteries were fabricated using a thin film of TiS{sub 2} prepared by chemical vapor deposition (CVD) as the cathode active material, a thin film of solid polymer prepared by plasma polymerization as the electrolyte, and a thin film of lithium deposited by thermal evaporation as the anode. The solid polymer electrolyte film was formed by complexation of plasma-polymerized tris (2-methoxyethoxy) vinylsilane with lithium perchlorate. Its room temperature conductivity was greater than 10{sup {minus}6} S cm{sup {minus}1} (10{sup 2} {Omega} cm{sup 2} resistance per unit area). The battery's discharge properties at room temperature and different current densities were examined. In this paper the effects of the interfaces between the solid polymer electrolyte and the electrodes on the battery's discharge performance are discussed.

  15. Preparation and optical characterization of DNA-riboflavin thin films

    NASA Astrophysics Data System (ADS)

    Paulson, Bjorn; Shin, Inchul; Kong, Byungjoo; Sauer, Gregor; Dugasani, Sreekantha Reddy; Khazaeinezhad, Reza; Jung, Woohyun; Joo, Boram; Oh, Kyunghwan

    2016-09-01

    Thin films of DNA biopolymer thin film are fabricated by a drop casting process on glass and silicon substrates, as well as freestanding. The refractive index is measured by elliposmetry and in bulk DNA film the refractive index is shown to be increased in the 600 to 900 nm DNA transparency window by doping with riboflavin. Further analysis with FT-IR, Raman, and XRD are used to determine whether binding between riboflavin and DNA occurs.

  16. Preparation and characterization of silk fibroin/HPMC blend film

    SciTech Connect

    Shetty, G. Rajesha; Kumar, R. Madhu; Rao, B. Lakshmeesha; Asha, S.; Sangappa

    2015-06-24

    In this work, the structural and mechanical stability of silk fibroin/Hydroxypropylmethyl cellulose (SF-HPMC) blend films were characterized by X-ray diffraction (XRD) and Universal Testing Machine (UTM). The results indicate that with the introduction of HPMC, the interactions between SF and HPMC results in improved crystallite size and increase in mechanical properties. The blend film obtained is more flexible compared to pure SF film.

  17. Preparation and characterization of tungsten oxide thin films with high electrochromic performance

    NASA Astrophysics Data System (ADS)

    Lv, Gang; Wu, Yonggang; Wu, Heyun; Ling, Leijie; Xia, Zihuan

    2010-10-01

    Tungsten oxide thin films were prepared by depositing WO3 onto glass substrates coated with ITO using reactive evaporation process at ambient temperature and 200°C respectively. The thin films were grown at different deposition rate. Chronoamperometry was carried out and spectral measurements were performed in situ. Results showed that the thin films prepared at low deposition rates possess higher coloration efficiency (CE), and the thin films grown at ambient temperature have high CE than those grown at 200°C. The origin of the differences in coloration efficiency of the thin films were analyzed and discussed based on the electrochromic mechanism of amorphous tungsten oxide films. The samples morphology was characterized by atom force microscopy (AFM).

  18. Preparation and characterization of tungsten oxide thin films with high electrochromic performance

    NASA Astrophysics Data System (ADS)

    Lv, Gang; Wu, Yonggang; Wu, Heyun; Ling, Leijie; Xia, Zihuan

    2011-02-01

    Tungsten oxide thin films were prepared by depositing WO3 onto glass substrates coated with ITO using reactive evaporation process at ambient temperature and 200°C respectively. The thin films were grown at different deposition rate. Chronoamperometry was carried out and spectral measurements were performed in situ. Results showed that the thin films prepared at low deposition rates possess higher coloration efficiency (CE), and the thin films grown at ambient temperature have high CE than those grown at 200°C. The origin of the differences in coloration efficiency of the thin films were analyzed and discussed based on the electrochromic mechanism of amorphous tungsten oxide films. The samples morphology was characterized by atom force microscopy (AFM).

  19. Preparation and characterization of titanium oxy-nitride thin films

    NASA Astrophysics Data System (ADS)

    Braic, M.; Balaceanu, M.; Vladescu, A.; Kiss, A.; Braic, V.; Epurescu, G.; Dinescu, G.; Moldovan, A.; Birjega, R.; Dinescu, M.

    2007-07-01

    The interest in TiN xO y films has increased recently due to their properties dependence on the N/O ratio. In this work, we studied comparatively the influence of different flow rate ratios of the reactive gases (O 2 and N 2) on the properties of the TiN xO y films deposited by two different methods: rf pulsed laser deposition (rf PLD) and reactive pulsed magnetron sputtering (RPM). Film structure and composition were studied by XRD and XPS methods, while film surface morphology was analyzed with AFM. Mechanical characteristics as Vickers microhardness and adhesion (scratch tests) were also determined.

  20. Effect of humidity on the a.c. impedance of CH3NH3SnCl3 hybrid films

    NASA Astrophysics Data System (ADS)

    Mosca, R.; Ferro, P.; Besagni, T.; Calestani, D.; Chiarella, F.; Licci, F.

    2011-09-01

    Impedance spectroscopy measurements show that complex conductivity of thermally ablated CH3NH3SnCl3 films is strongly enhanced when humidity increases. Coplanar two-electrode test devices are modeled through an equivalent circuit comprising one resistance and two constant phase elements. It is shown that the influence of ambient humidity is mainly resistive. The dynamic responses of the devices to humidification/dehumidification cycles point out that the a.c. current varies by more than three orders of magnitude when humidity is varied between dry air and 80% relative humidity. The rise times are few hundred seconds while fall times are as short as few tens of seconds. This observation suggests that impedance variations are determined by mechanisms involving loosely bound water molecules physisorbed at the surface of the hybrid film. The results obtained are discussed in terms of protonic conduction.

  1. Electrochromic properties of molybdenum trioxide thin films prepared by chemical vapor deposition

    SciTech Connect

    Maruyama, Toshiro; Kanagawa, Tetsuya

    1995-05-01

    Electrochromic molybdenum trioxide thin films were prepared by chemical vapor deposition. The source material was molybdenum carbonyl. Amorphous molybdenum trioxide thin films were produced at a substrate temperature 300 C. Reduction and oxidation of the films in a 0.3M LiClO{sub 4} propylene carbonate solution caused desirable changes in optical absorption. Coulometry indicated that the coloration efficiency was 25.8 cm{sup 2}/C.

  2. Preparation and photoactivity of nanostructured anatase, rutile and brookite TiO2 thin films.

    PubMed

    Addamo, Maurizio; Bellardita, Marianna; Di Paola, Agatino; Palmisano, Leonardo

    2006-12-21

    Photoactive films consisting of pure anatase, brookite or rutile TiO2 were prepared by dip coating from water dispersions obtained by using TiCl4 as the precursor under similar mild experimental conditions.

  3. Dispersion of functional tetraphenylporphyrin-ligated metal into ultra-thin flexible acrylate films. 1. Preparation of thin films.

    PubMed

    Choe, Youngson; Kim, Taesu; Kim, Wonho

    2004-11-15

    As functional metal complexes, copper phthalocyanine (CuPc) and Cobalt (II) meso-tetraphenylporphyrin (CoTPP) were chosen to prepare metal complex/polymer hybrid thin films which were prepared by metal complex sublimation and reactive monomer evaporation onto the glass substrate in the bell jar reactor in vacuum conditions. The polarized transmission micrograph images show that the film deposited at 80 degrees C contains uniformly dispersed tiny grains and the film deposited at 30 degrees C is amorphous and homogeneous. As the deposition rate increases, the crystalline clusters were found and were dispersed uniformly. Those crystalline clusters are not to be developed by recrystallization process. Deposited metal complex/acrylate hybrid thin films were in situ photopolymerized. The kinetics of photopolymerization was investigated by attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR). The thickness of the films was about 200 nm. The reactive monomer acts as a solvent to avoid the recrystallization of metal complexes and to have two-compositional continuous phase. The percent of metal complex can be adjusted up to 60% by controlling the metal complex sublimation rate. A good achievement in the uniformity and continuity of the film matrix has been made and the recrystallization of metal complex in the hybrid films has not been observed.

  4. Ferroelectric thin film bismuth titanate prepared from acetate precursors

    SciTech Connect

    Lu, Yanxia; Hoelzer, D.T.; Schulze, W.A.; Tuttle, B.A.; Potter, B.G.

    1994-10-01

    Bismuth titanate (Bi{sub 4}Ti{sub 3}O{sub 12}) thin films were fabricated by spin coat deposition followed by rapid thermal processing (RTP). Acetate derived solutions for deposition were synthesized by blending bismuth acetate in aqueous acetic acid and then adding titanium acetate. A series of electrically insulating, semiconducting and conducting substrates were evaluated for Bi{sub 4}Ti{sub 3}O{sub 12} film deposition. While X-ray diffraction and TEM analyses indicated that the initial perovskite crystallization temperature was 500{degrees}C or less for these Bi{sub 4}Ti{sub 3}O{sub 12} films, a 700{degrees}C crystallization treatment was used to obtain single phase perovskite films. Bi{sub 4}Ti{sub 3}O{sub 12} film crystallographic orientation was shown to depend on three factors: substrate surface morphology, the number of coating layers and thermal processing. While preferred c-direction orientation was observed for Bi{sub 4}Ti{sub 3}O{sub 12} films deposited on silver foil substrates, preferred a-direction orientation was obtained for films deposited on both Si and Pt coated Si wafers. The films were dense, smooth, crack free, and had grain sizes ranging from 20 nm to 100 nm. Film thickness and refractive index were determined using a combination of ellipsometry, waveguide refractometry and TEM measurements. Both low field dielectric and ferroelectric properties were measured for an 800 nm thick film deposited on a Pt coated MgO substrate. A remanent polarization of 38 {mu}C/cm{sup 2} and a coercive field of 98 kV/cm were measured for this film that was crystallized at 700{degrees}C.

  5. Preparation of gelatin films incorporated with tea polyphenol nanoparticles for enhancing controlled-release antioxidant properties

    USDA-ARS?s Scientific Manuscript database

    Tea polyphenols (TP) were incorporated into edible gelatin films either alone or incorporated into nanoparticles in order to determine the physico-chemical properties of the film and the antioxidant properties of TP in a solid gelatin matrix. The TP containing nanoparticles were prepared by cross-li...

  6. Disinfection studies on TiO2 thin films prepared by a sol-gel method.

    PubMed

    Kambala, Venkata Subba Rao; Naidu, Ravi

    2009-02-01

    Transparent anatase TiO2 nanometer thin films were prepared by dip-coating on soda-lime glass plates via the sol-gel method. The un-calcined and the calcined films were characterized by X-ray diffraction (XRD), AFM, Nano-indentation (hardness and Young's modulus), UV-vis spectrometry, thickness and hydrophilicity (contact angle measurements). The photocatalytic activity of the thin films was evaluated by performing disinfection studies on the Gram-negative microorganisms like Escherichia coli, and Staphylococcus Aureus, a Gram-positive organism. The photocatalytic activity for both groups of organisms was studied in saline and nutrient broth. The leakage of potassium from the bacteria was observed parallel to cell viability. The activity of the sol-gel prepared TiO2 thin films were compared under UV lamps and natural day light (ND) lamps with Degussa P-25 TiO2 thin films prepared on soda-lime glass using a polymer support and the commercial self-cleaning glass (SC). The sol-gel prepared thin films which were annealed at 450 degrees C, show highest photocatalytic activity, the slowest conversion rate from hydrophilic to a hydrophobic state, light-induced hydrophilicity, and also higher disinfection activities compared to P-25 films and commercial self-cleaning glass. The films also show excellent activities when continuously reused for more than a month.

  7. Preparation and characterization of cellulose acetate organic/inorganic hybrid films

    Treesearch

    Saeed S. Shojaie; Timothy G. Rials; Stephen S. Kelley

    1995-01-01

    A series of organic/inorganic hybrid (OIH) films were prepared using cellulose acetate (CA) as the organic component and tetraethyl orthosilicate (TEOS) as the inorganic component. The chemical, morphological, and mechanical properties of these films were evaluated with a variety of analytical techniques. The results of these evaluations showed that crosslinked CA OIH...

  8. Cell proliferation on modified DLC thin films prepared by plasma enhanced chemical vapor deposition.

    PubMed

    Stoica, Adrian; Manakhov, Anton; Polčák, Josef; Ondračka, Pavel; Buršíková, Vilma; Zajíčková, Renata; Medalová, Jiřina; Zajíčková, Lenka

    2015-06-12

    Recently, diamondlike carbon (DLC) thin films have gained interest for biological applications, such as hip and dental prostheses or heart valves and coronary stents, thanks to their high strength and stability. However, the biocompatibility of the DLC is still questionable due to its low wettability and possible mechanical failure (delamination). In this work, DLC:N:O and DLC: SiOx thin films were comparatively investigated with respect to cell proliferation. Thin DLC films with an addition of N, O, and Si were prepared by plasma enhanced CVD from mixtures of methane, hydrogen, and hexamethyldisiloxane. The films were optically characterized by infrared spectroscopy and ellipsometry in UV-visible spectrum. The thickness and the optical properties were obtained from the ellipsometric measurements. Atomic composition of the films was determined by Rutherford backscattering spectroscopy combined with elastic recoil detection analysis and by x-ray photoelectron spectroscopy. The mechanical properties of the films were studied by depth sensing indentation technique. The number of cells that proliferate on the surface of the prepared DLC films and on control culture dishes were compared and correlated with the properties of as-deposited and aged films. The authors found that the level of cell proliferation on the coated dishes was high, comparable to the untreated (control) samples. The prepared DLC films were stable and no decrease of the biocompatibility was observed for the samples aged at ambient conditions.

  9. Preparation and properties of nanometer silk fibroin peptide/polyvinyl alcohol blend films for cell growth.

    PubMed

    Luo, Qin; Chen, Zhongmin; Hao, Xuefei; Zhu, Qiangsong; Zhou, Yucheng

    2013-10-01

    Nanometer silk fibroin peptide (Nano-SFP) was prepared from silkworm cocoons through the process of dissolution, dialysis and enzymolysis. For comparison, silk fibroin was decomposed with α-chymotrypsin, trypsin and neutrase, respectively. From the SEM and particle size analysis results, the Nano-SFP prepared by neutrase was found to be the most desirable at about 50-200 nm. Nano-SFP/polyvinyl alcohol films (Nano-SFP/PVA) were prepared by blending Nano-SFP and PVA in water with different weight ratios of 10/90, 20/80, 30/70, and 40/60. The films were characterized by IR, SEM, TG, DSC and tensile strength test for investigating their structure, surface morphology, thermostability, and mechanical property. The results showed that Nano-SFP inserted in the PVA films with small linear particles, and Nano-SFP/PVA films exhibited smooth surface, good thermostability and tensile strength. The growth of Chinese hamster ovary (CHO) cells on films with and without Nano-SFP was investigated with MTT colorimetric assay to assess the films' ability to promote cell growth. It was observed that the Nano-SFP improved cell adhesion on the film surface, and the ability of promoting cell growth increased with the increasing content of Nano-SFP in the blend films. Nano-SFP/PVA film with the ratio of 30/70 was concluded to have the best properties.

  10. Preparation and evaluation of hemicellulose films and their blends

    USDA-ARS?s Scientific Manuscript database

    Cell wall hemicelluloses are useful in various industries due to their ability to form edible and biodegradable films with plasticizers such as glycerol. The objective of this research was to extract hemicelluloses from Caesalpina pulcherrima and Tamarindus indica, produce film blends from them, and...

  11. Preparation of hydrophilic polyhydroxyalkyl glutamine crosslinked films and its biodegradability.

    PubMed

    Pan, Shi-Rong; Wang, Qin-Mei; Yi, Wu

    2007-09-01

    Polybenzyl glutamate (PBLG) or polymethyl glutamate (PMLG) films have been aminolyzed with amino alcohol and crosslinked with aliphatic diamine at 60 degrees C for 48 h simultaneously which led to the formation of crosslinked films of polyhydroxyalkyl glutamine (PHAG). ATR-IR indicates that for the aminolysis of PBLG with 2-amino-1-ethanol or 3-amino-1-propanol, benzyl glutamate almost completely turned to hydroxyalkyl glutamine, however for the aminolysis of PMLG with 5-amino-1-pentanol, methyl glutamate partially turned to hydroxypentanyl glutamine. The water-swelling test shows that water-swelling ratio Q of PHAG films from amino alcohol with longer carbon chain was smaller, the PHAG films crosslinked by 1,2-diamino ethane have the higher water-swelling ratio Q, but the PHAG films crosslinked by 1,8-diamino octane have the lower water swelling ratio Q; and PHAG films with a greater amount of crosslinking agents have high crosslinking density or the low water swelling-ratio Q for same amino alcohol and diamine. It is obvious from in vitro enzymatic hydrolysis test that specimens with smaller swelling ratio Q displayed larger T(1/2), time for half weight digestion of PHAG film, that is, less biodegradability. Therefore, biodegradability of the crosslinked PHAG films can be controlled by changing amino alcohol and diamine.

  12. Preparation and characterization of bionanocomposite films reinforced with nano kaolin.

    PubMed

    Jafarzadeh, Shima; Alias, Abd Karim; Ariffin, Fazilah; Mahmud, Shahrom; Najafi, Ali

    2016-02-01

    Effects of nano-kaolin incorporation into semolina films on the physical, mechanical, thermal, barrier and antimicrobial properties of the resulting bio-nanocomposite films were investigated. The properties included crystal structure (by X-ray diffraction), mechanical resistance, color, Fourier transform infrared spectra, decomposition temperature, water-vapor permeability (WVP), oxygen permeability (OP), and antimicrobial activity against Staphylococcus aureus and Escherichia coli. Kaolin was incorporated into biofilms at various amounts (1, 2, 3, 4, and 5 %, w/w total solid). All films were plasticized with 50 % (w/w total solid) combination of sorbitol/glycerol at 3:1 ratio. The incorporation of nanokaolin into semolina films decreased OP and WVP. The moisture content and water solubility of the films were found to decrease by nanokaolin reinforcement, and mechanical properties of films were improved by increasing nanokaolin concentration. Tensile strength and Young's modulus increased from 3.41 to 5.44 MPa and from 63.12 to 136.18, respectively, and elongation-at-break decreased. The films did not exhibit UV absorption. In conclusion, nanokaolin incorporation enhanced the barrier and mechanical properties of semolina films, indicating the potential application of these bio-nanocomposites in food-product packaging.

  13. Preparation and characterization of highly oriented films and membranes of zeolite A

    NASA Astrophysics Data System (ADS)

    Boudreau, Laura Catherine

    1999-11-01

    Zeolite NaA films and membranes have been prepared using both in situ and seeded growth preparation processes. Films prepared using in situ preparations have shown this technique to be unsuitable for further development due to its inability to control the film microstructure, poor reproducibility, and dissolution of the substrate resulting in amorphous material incorporated in the film. Seeded growth, however, shows the ability to prepare highly oriented zeolite NaA films, the first zeolite films reported with this high degree of orientation. For the seeded growth preparation, nanometer sized zeolite particles are used in suspension to cast seed films. These films are prepared using dip coating, film casting, and electrostatic deposition. The seed films show a high degree of orientation with the [h00] planes of the seed crystals aligned parallel to the substrate surface. A higher degree of orientation where the particles are deposited in a hexagonal packed array can be achieved using dip coating with extremely slow withdrawal rates (˜1 cm/hr). These seed films are then subjected to a secondary growth process to eliminate the interzeolitic pores and form continuous zeolite layers. This has been achieved with clear solutions or gels resulting in continuous films 0.5 to 7mum thick with a high degree of orientation. The regrowth mechanism was investigated and results indicate that the growth of zeolite A films proceeds by multiple processes including epitaxial growth of the seeds and deposition of particles from solution. The membranes have been used for alcohol/water pervaporation. The membranes are highly selective for water and show selectivities >3,100 for water using (90/10) ethanol/water feed systems. In permeation measurements, these membranes show no selectivities other than Knudsen for permanent gases. Unlike Knudsen diffusion, these membranes show increasing permeation with increasing temperature. This indicates the probability of small defects in the films

  14. Low-temperature preparation of anatase thin films on tantalum.

    PubMed

    Johnson, Scott E; Burgoon, Matthew W P; Wang, Qi; White, J M

    2006-07-18

    Titanium dioxide thin films were grown on oxidized Ta surfaces using a cyclic layer-by-layer wet chemistry method: successive-ionic-layer-adsorption-and-reaction (SILAR). Film thicknesses varied monotonically and approximately linearly with the number of cycles. As-grown (AG) films were amorphous and rougher (16.2 nm root-mean-square (rms)) than the Ta substrate (10.2 nm rms). After hydrothermal annealing (AN) at a remarkably low temperature of 393 K, the films exhibited anatase crystallites (10 nm dimensions) and reduced roughness (11.8 nm rms). The atomic composition of both AG and AN films was consistent with that of TiO2 containing no more than 4 atom % carbon. A small Si impurity (<1 atom %) was eliminated by using polypropylene beakers and sample holders in the SILAR steps.

  15. Optical properties of bismuth sulfide thin film prepared by thermal evaporation method

    NASA Astrophysics Data System (ADS)

    Kachari, T.; Rahman, A.

    2015-04-01

    Two types of thin films of Bi2S3 have been prepared on chemically cleaned glass substrate by thermal evaporation technique. Either by thermal evaporation of Bi2S3 powder or by thermal evaporation of bismuth and sulfur from two separate source. (Both annealed for 3 h in air inside an oven). Optical properties of these annealed films have been studied by measuring transmittance, absorbance and reflectance of the films. Optical constants such as absorption coefficient, extinction constants, refractive index, dielectric constants etc. of both types of Bi2S3 films have been calculated. Optical band gap of type (I) and (II) films have been found to be 1.647 and 1.668 eV respectively. The crystalline structure and purity of these Bi2S3 films have been studied by taking X-ray diffraction and X-ray fluorescence spectra. Surface morphology of the films has been studied by scanning electron microscopy.

  16. Preparation of Grayish Black Film on AM50 Magnesium Alloy by Chemical Conversion-Micro Oxidation

    NASA Astrophysics Data System (ADS)

    Shao, Zhongcai; Zhang, Feifei; Zhang, Qingfang; Yang, Li; Shen, Xiaoyi

    2017-07-01

    The grayish black film was prepared on AM50 magnesium alloy with a new method which combined chemical conversion with micro-arc oxidation (MAO). The optimum formula of chemical conversion was obtained by L9(34) orthogonal test. Meanwhile, the morphology, structure, composition and corrosion resistance of films were analyzed by scanning electron microscopy (SEM), energy spectrum analysis (energy dispersive X-ray spectroscopy (EDS)), X-ray diffraction (XRD), electrochemical tests and CuSO4 drip experiment. The results indicated that Mo element was introduced into the MAO film by chemical conversion pretreatment. The surface of composite film was smooth and compact. The main phase composition of the composite film were SiO2, Mo9O26, MgSiO3, Mg2SiO4 and Mo9O26 was identified to be responsible for giving color to the film. The corrosion resistance of the grayish black film was improved obviously.

  17. Preparation and characterization of bio-based hybrid film containing chitosan and silver nanowires.

    PubMed

    Shahzadi, Kiran; Wu, Lin; Ge, Xuesong; Zhao, Fuhua; Li, Hui; Pang, Shuping; Jiang, Yijun; Guan, Jing; Mu, Xindong

    2016-02-10

    A bio-based hybrid film containing chitosan (CS) and silver nanowires (AgNWs) has been prepared by a simple casting technique. X-ray diffraction (XRD), Fourier infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and UV-visible spectroscopy were employed to characterize the structure of bio-based film. The bio-based hybrid film showed unique performance compared with bare chitosan film. The incorporated nano-silver could improve the strength properly. The results revealed that AgNWs in CS film, improved its tensile strength more than 62% and Young modulus 55% compared with pure chitosan film. On the other hand tensile strength was increased 36.7% with AgNPs. Importantly, the film also exhibited conductivity and antibacterial properties, which may expand its future application. Copyright © 2015. Published by Elsevier Ltd.

  18. An attempt to prepare nonchromate, self-healing protective films containing molybdate on iron

    SciTech Connect

    Aramaki, K.

    1999-11-01

    Preparation of a nonchromate, self-healing protective film on an Fe surface was attempted. A protective film of 1,2-bis(triethoxysilyl)ethane ([C{sub 2}H{sub 5}O]{sub 3} Si[CH{sub 2}]{sub 2} Si[OC{sub 2}H{sub 5}]{sub 3}) polymer containing a fine powder of ammonium heptamolybdate tetrahydrate ([NH{sub 4}]{sub 6}Mo{sub 7}O{sub 24} {center{underscore}dot} 4H{sub 2}O) was prepared on a surface of Fe electrode passivated in aerated 0.1-M sodium molybdate (Na{sub 2}MoO{sub 4}). The protective ability of this film was examined on the covered electrode in an aerated 0.1-M sodium chloride (NaCl) solution at 30 C by polarization measurement. The protection efficiency (P) of the film was significantly high, 99.0%. After the electrode coated with the film was scratched with a knife edge, the self-healing ability of the film was estimated on the electrode in the NaCl solution by polarization measurement. The P value of the film on the scratched electrode was still high, 98.8%. The anodic process of Fe corrosion markedly was suppressed by the formation of a passive film at the scratched surface with molybdate ion (MoO{sub 4}{sup {minus}}) incorporated in the polymer film, resulting in a self-healing activity of the film.

  19. Preparation methodologies and nano/microstructural evaluation of metal/semiconductor thin films.

    PubMed

    Chen, Zhiwen; Jiao, Zheng; Wu, Minghong; Shek, Chan-Hung; Wu, C M Lawrence; Lai, Joseph K L

    2012-01-01

    Metal/semiconductor thin films are a class of unique materials that are widespread technological applications, particularly in the field of microelectronic devices. Assessment strategies of fractal and tures are of fundamental importance in the development of nano/microdevices. This review presents the preparation methodologies and nano/microstructural evaluation of metal/semiconductor thin films including Au/Ge bilayer films and Pd-Ge alloy thin films, which show in the form of fractals and nanocrystals. Firstly, the extended version of Au/Ge thin films for the fractal crystallization of amorphous Ge and the formation of nanocrystals developed with improved micro- and nanostructured features are described in Section 2. Secondly, the nano/microstructural characteristics of Pd/Ge alloy thin films during annealing have been investigated in detail and described in Section 3. Finally, we will draw the conclusions from the present work as shown in Section 4. It is expected that the preparation methodologies developed and the knowledge of nano/microstructural evolution gained in metal/semiconductor thin films, including Au/Ge bilayer films and Pd-Ge alloy thin films, will provide an important fundamental basis underpinning further interdisciplinary research in these fields such as physics, chemistry, materials science, and nanoscience and nanotechnology, leading to promising exciting opportunities for future technological applications involving these thin films.

  20. Oxidation Temperature Effects on ZnO Thin Films Prepared from Zn Thin Films on Quartz Substrates.

    PubMed

    Park, Seonhee; Kim, Younggyu; Leem, Jae-Young

    2015-11-01

    We investigated the structural and optical properties of the ZnO thin films formed by oxidation of Zn thin films. Zn thin films were deposited by thermal evaporation and were then annealed from 300 to 800 degrees C to prepare ZnO thin films. We found that ZnO thin films were formed by thermal oxidation of Zn thin films at oxidation temperatures over 400 degrees C. The grain size of ZnO thin films increased with the oxidation temperature and the highest ZnO (002) intensity was obtained at 600 degrees C. In the PL spectra, the intensity of the near-band-edge peak increased with the oxidation temperatures until 400 degrees C. However, these values gradually decreased with a further increase in the oxidation temperatures over 400 degrees C. The transmittance of the ZnO thin films was more than 90% for the visible wavelength region, and the optical band gap was red-shifted with increase in the oxidation temperature.

  1. Design and preparation of stress-free epitaxial BaTiO3 polydomain films by RF magnetron sputtering

    PubMed Central

    Zhang, Wei; Yuan, Meiling; Wang, Xianyang; Pan, Wei; Wang, Chun-Ming; Ouyang, Jun

    2012-01-01

    Domain structures of BaTiO3 thick films grown on (100) SrTiO3 single-crystal substrates were engineered using an RF magnetron sputtering deposition process. By tuning the sputtering power and cooling rate and using an off-axis sputtering technique to prepare conducting perovskite oxide bottom electrode with heteroepitaxial quality, we have deposited epitaxial tetragonal single-domain and polydomain BaTiO3 films with a self-assembled three-domain architecture. The electrical properties and microstructure of the BaTiO3 films were characterized, and a c/a1/a2 cellular polydomain structure was clearly observed in as-grown films by optical microscopy. Such a polydomain structure was a consequence of a complete relaxation of misfit stresses of the film. Engineering of this self-assembled microstructure has great potential in providing large, field-tunable pyroelectric and electromechanical responses in next-generation microelectronic devices and micro-electro-mechanical systems (MEMS). PMID:27877494

  2. Design and preparation of stress-free epitaxial BaTiO3 polydomain films by RF magnetron sputtering.

    PubMed

    Zhang, Wei; Yuan, Meiling; Wang, Xianyang; Pan, Wei; Wang, Chun-Ming; Ouyang, Jun

    2012-06-01

    Domain structures of BaTiO3 thick films grown on (100) SrTiO3 single-crystal substrates were engineered using an RF magnetron sputtering deposition process. By tuning the sputtering power and cooling rate and using an off-axis sputtering technique to prepare conducting perovskite oxide bottom electrode with heteroepitaxial quality, we have deposited epitaxial tetragonal single-domain and polydomain BaTiO3 films with a self-assembled three-domain architecture. The electrical properties and microstructure of the BaTiO3 films were characterized, and a c/a1/a2 cellular polydomain structure was clearly observed in as-grown films by optical microscopy. Such a polydomain structure was a consequence of a complete relaxation of misfit stresses of the film. Engineering of this self-assembled microstructure has great potential in providing large, field-tunable pyroelectric and electromechanical responses in next-generation microelectronic devices and micro-electro-mechanical systems (MEMS).

  3. Design and preparation of stress-free epitaxial BaTiO3 polydomain films by RF magnetron sputtering

    NASA Astrophysics Data System (ADS)

    Zhang, Wei; Yuan, Meiling; Wang, Xianyang; Pan, Wei; Wang, Chun-Ming; Ouyang, Jun

    2012-06-01

    Domain structures of BaTiO3 thick films grown on (100) SrTiO3 single-crystal substrates were engineered using an RF magnetron sputtering deposition process. By tuning the sputtering power and cooling rate and using an off-axis sputtering technique to prepare conducting perovskite oxide bottom electrode with heteroepitaxial quality, we have deposited epitaxial tetragonal single-domain and polydomain BaTiO3 films with a self-assembled three-domain architecture. The electrical properties and microstructure of the BaTiO3 films were characterized, and a c/a1/a2 cellular polydomain structure was clearly observed in as-grown films by optical microscopy. Such a polydomain structure was a consequence of a complete relaxation of misfit stresses of the film. Engineering of this self-assembled microstructure has great potential in providing large, field-tunable pyroelectric and electromechanical responses in next-generation microelectronic devices and micro-electro-mechanical systems (MEMS).

  4. Substrate Preparations in Epitaxial ZnO Film Growth

    NASA Technical Reports Server (NTRS)

    Zhu, Shen; Su, C.-H.; Lehoczky, S. L.; Harris, M. T.; Callahan, M. J.; George, M. A.

    2000-01-01

    Epitaxial ZnO films were grown on the two polar surfaces (O-face and Zn-face) of (0001) ZnO single crystal substrates using off-axis magnetron sputtering deposition. Annealing-temperature dependence of ZnO substrates was studied. ZnO films grown on sapphire substrates have also been investigated for comparison purposes and the annealing temperature of A1203 substrates is 1000 C. Substrates and films were characterized using photoluminescence (PL) spectrum, x-ray diffraction, atomic force microscope, energy dispersive spectrum, and electric transport measurements. It has been found that the ZnO film properties were different when films were grown on the two polarity surfaces of ZnO substrates and the A1203 substrates. An interesting result shows that high temperature annealing of ZnO single crystals will improve the surface structure on the O-face surface rather than the opposite surface. The measurements of homoepitaxial ZnO films indicate that the O-terminated surface is better for ZnO epitaxial film growth.

  5. Electrical Properties of CZO Films Prepared by Ultrasonic Spray Pyrolysis

    PubMed Central

    Chen, Lung-Chien; Hsieh, Cheng-An; Zhang, Xiuyu

    2014-01-01

    CuZnO (CZO) films have attracted increasing amounts of attention due to their promising potential applications in semiconductor devices. ZnO shows n-type conductivity, and attempts have been made to dope several elements in ZnO to improve the electrical properties. This study investigated the electrical property transitions of CZO films and determined the copper concentration at which the conductivity of CZO films will change from n-type to p-type. In this study, CZO films were fabricated by ultrasonic spray pyrolysis with copper acetate, zinc acetate, and ammonium acetate precursor solution. The concentrations of Cu ions in the CZO films were controlled by the concentration ratios of copper acetate to zinc acetate in the precursor solutions. In addition, these samples were analyzed by Hall effect measurements, X-ray diffraction, transmittance measurements, and photoluminescence measurements. The results show that the conductivity of the CZO film changes from n-type to p-type when the copper ion concentration in the film is 5%. PMID:28788247

  6. Temperature dependent properties of silicon containing diamondlike carbon films prepared by plasma source ion implantation

    NASA Astrophysics Data System (ADS)

    Hatada, R.; Flege, S.; Baba, K.; Ensinger, W.; Kleebe, H.-J.; Sethmann, I.; Lauterbach, S.

    2010-04-01

    Silicon containing diamondlike carbon (Si-DLC) films were prepared on silicon wafer substrates by a plasma source ion implantation method with negative pulses superposed on a negative dc voltage. A mixture of acetylene and tetramethylsilane gas was introduced into the discharge chamber as working gases for plasma formation. Ions produced in the plasma are accelerated toward a substrate holder because of the negative voltage applied directly to it. After deposition, the films were annealed for 0.5 h in ambient air at temperatures up to 923 K in order to evaluate the thermal stability of the Si-DLC films. The films were analyzed by x-ray photoelectron spectroscopy (XPS), high resolution transmission electron microscopy, and Raman spectroscopy. The surface morphology of the films and the film thickness were observed by atomic force microscopy and scanning electron microscopy. The mechanical and tribological properties were investigated by an indentation method and a ball-on-disk test. The results show the silicon containing DLC films were amorphous and the surface roughness of the Si containing DLC films was very smooth and no special structure was observed. Integrated intensity ratios ID/IG of Raman spectroscopy of the Si containing DLC films decreased with Si content. The Raman spectra showed that the structure of the Si-free DLC film changed to a graphitelike structure with increasing annealing temperature, whereas that of the 24 at. % Si containing DLC films did not change at the maximum temperature used in this study. A very low friction coefficient was obtained for the 13 at. % Si containing DLC film. The surface roughness and the hardness of the films changed with increasing annealing temperature. The formation of Si oxide in a near surface layer was confirmed by XPS and it prevents further oxidation of the inside of the film. Heat resistivity of DLC films can be improved by Si addition into the DLC films.

  7. Process for preparing group Ib-IIIa-VIa semiconducting films

    DOEpatents

    Birkmire, R.W.; Schultz, J.M.; Marudachalam, M.; Hichri, H.

    1997-10-07

    Methods are provided for the production of supported monophasic group I-III-VI semiconductor films. In the subject methods, a substrate is coated with group I and III elements and then contacted with a reactive group VI element containing atmosphere under conditions sufficient to produce a substrate coated with a composite of at least two different group I-III-IV alloys. The resultant composite coated substrate is then annealed in an inert atmosphere under conditions sufficient to convert the composite coating to a monophasic group I-III-VI semiconductor film. The resultant supported semiconductor films find use in photovoltaic applications, particularly as absorber layers in solar cells. 4 figs.

  8. Preparation of polymeric diacetylene thin films for nonlinear optical applications

    NASA Technical Reports Server (NTRS)

    Frazier, Donald O. (Inventor); Mcmanus, Samuel P. (Inventor); Paley, Mark S. (Inventor); Donovan, David N. (Inventor)

    1995-01-01

    A method for producing polymeric diacetylene thin films having desirable nonlinear optical characteristics has been achieved by producing amorphous diacetylene polymeric films by simultaneous polymerization of diacetylene monomers in solution and deposition of polymerized diacetylenes on to the surface of a transparent substrate through which ultraviolet light has been transmitted. These amorphous polydiacetylene films produced by photo-deposition from solution possess very high optical quality and exhibit large third order nonlinear optical susceptibilities, such properties being suitable for nonlinear optical devices such as waveguides and integrated optics.

  9. Process for preparing group Ib-IIIa-VIa semiconducting films

    DOEpatents

    Birkmire, Robert W.; Schultz, Jerold M.; Marudachalam, Matheswaran; Hichri, Habib

    1997-01-01

    Methods are provided for the production of supported monophasic group I-III-VI semiconductor films. In the subject methods, a substrate is coated with group I and III elements and then contacted with a reactive group VI element containing atmosphere under conditions sufficient to produce a substrate coated with a composite of at least two different group I-III-IV alloys. The resultant composite coated substrate is then annealed in an inert atmosphere under conditions sufficient to convert the composite coating to a monophasic group I-III-VI semiconductor film. The resultant supported semiconductor films find use in photovoltaic applications, particularly as absorber layers in solar cells.

  10. Preparation of superhydrophobic nanodiamond and cubic boron nitride films

    NASA Astrophysics Data System (ADS)

    Zhou, Y. B.; Yang, Y.; Liu, W. M.; Ye, Q.; He, B.; Zou, Y. S.; Wang, P. F.; Pan, X. J.; Zhang, W. J.; Bello, I.; Lee, S. T.

    2010-09-01

    Superhydrophobic surfaces were achieved on the hardest and the second hardest materials, diamond and cubic boron nitride (cBN) films. Various surface nanostructures of nanocrystalline diamond (ND) and cBN films were constructed by carrying out bias-assisted reactive ion etching in hydrogen/argon plasmas; and it is shown that surface nanostructuring may enhance dramatically the hydrophobicity of ND and cBN films. Together with surface fluorination, superhydrophobic ND and cBN surfaces with a contact angle greater than 150° and a sliding angle smaller than 10° were demonstrated. The origin of hydrophobicity enhancement is discussed based on the Cassie model.

  11. Preparation of variable-thickness MgB 2 thin film bridges by AFM nanolithography

    NASA Astrophysics Data System (ADS)

    Gregor, M.; Plecenik, A.; Plecenik, T.; Tomasek, M.; Kus, P.; Micunek, R.; Stefecka, M.; Zahoran, M.; Grancic, B.; Kubinec, M.; Gasparik, V.

    2006-03-01

    In this paper we focus our attention on preparation of superconducting MgB2 thin films and variable-thickness MgB2 thin film bridges using the Atomic Force Microscope nanolithographic technique. Microstructures and their following variable-thickness bridges were prepared on nonsuperconducting MgB thin films. Final structures were annealed in argon atmosphere at temperature 680 °C and exhibit transition to the superconducting state Tcon = 33 K and zero critical temperature Tc0 = 30.5 K. Critical current density jc (4.2 K) measured on the bridge was higher than 106 A/cm2.

  12. Preparation of TiO2 thin films using water-soluble titanium complexes and their photoinduced properties.

    PubMed

    Katsumata, Ken-ichi; Ohno, Yukiaki; Tomita, Koji; Sakai, Munetoshi; Nakajima, Akira; Kakihana, Masato; Fujishima, Akira; Matsushita, Nobuhiro; Okada, Kiyoshi

    2011-01-01

    Titanium dioxide thin films were prepared by using four water-soluble titanium complexes of titanium-lactate, tartalate, malate and salicylate complex solutions. The crystalline phases detected in the films were anatase. The surface microstructures of the four film samples were different in their grain sizes. Photocatalytic decomposition activity of the four films was almost the same, but their photoinduced hydrophilicities were different. The film prepared using titanium-salicylate complex exhibited lower hydrophilic conversion rate than the other films. Grain size and stress yielded to the film are considered to be important factors on the photoinduced hydrophilicity.

  13. Anisotropic surface properties of micro/nanostructured a-C:H:F thin films with self-assembly applications

    NASA Astrophysics Data System (ADS)

    Freire, V.-M.; Corbella, C.; Bertran, E.; Portal-Marco, S.; Rubio-Roy, M.; Andújar, J.-L.

    2012-06-01

    The singular properties of hydrogenated amorphous carbon (a-C:H) thin films deposited by pulsed DC plasma enhanced chemical vapor deposition (PECVD), such as hardness and wear resistance, make it suitable as protective coating with low surface energy for self-assembly applications. In this paper, we designed fluorine-containing a-C:H (a-C:H:F) nanostructured surfaces and we characterized them for self-assembly applications. Sub-micron patterns were generated on silicon through laser lithography while contact angle measurements, nanotribometer, atomic force microscopy (AFM), and scanning electron microscopy (SEM) were used to characterize the surface. a-C:H:F properties on lithographied surfaces such as hydrophobicity and friction were improved with the proper relative quantity of CH4 and CHF3 during deposition, resulting in ultrahydrophobic samples and low friction coefficients. Furthermore, these properties were enhanced along the direction of the lithography patterns (in-plane anisotropy). Finally, self-assembly properties were tested with silica nanoparticles, which were successfully assembled in linear arrays following the generated patterns. Among the main applications, these surfaces could be suitable as particle filter selector and cell colony substrate.

  14. Preparation and characterization of the nanoporous ultrathin multilayer films based on molybdenum polyoxometalate (Mo 38) n

    NASA Astrophysics Data System (ADS)

    Wang, L.; Jiang, M.; Wang, E. B.; Duan, L. Y.; Hao, N.; Lan, Y.; Xu, L.; Li, Z.

    2003-11-01

    Ultrathin multilayer films of the wheel-shaped molybdenum polyoxometalate cluster (Mo 38) n and poly(allylamine hydrochloride)(PAH) have been prepared by the layer-by-layer (LbL) self-assembly method. The ((Mo 38) n/PAH) m multilayer films have been characterized by X-ray photoelectron spectra (XPS) and atomic force microscopy (AFM). UV-VIS measurements reveal regular film growth with each (Mo 38) n adsorption. The electrochemistry behavior of the film at room temperature was investigated.

  15. Study of photoconductivity in Ni doped CdS thin films prepared by spray pyrolysis technique

    SciTech Connect

    Patidar, Manju Mishra Gangrade, Mohan; Nath, R.; Ganesan, V.; Ajay, Akhil; Wala, Arwa Dewas; N, Kiran; Panda, Richa

    2014-04-24

    Ni-doped cadmium sulphide [Cd{sub 1−x}Ni{sub x}S, (x=0, 0.03, 0.05 and 0.20)] thin films were investigated for photoconductive properties. The films were prepared by spray Pyrolysis technique (SPT). AFM and two probe resistivity measurements were carried out to analyze the morphological and electrical properties of the films. AFM shows the note worthy changes in the morphology where the nanorod structures in CdS is changed into nano particles with the Ni doping. The presence of persistence photo current is demonstrated and extensive photoconductivity analysis has been studied on these films.

  16. CoNi Films with Perpendicular Magnetic Anisotropy Prepared by Alternate Monoatomic Layer Deposition

    NASA Astrophysics Data System (ADS)

    Fukami, Shunsuke; Sato, Hideo; Yamanouchi, Michihiko; Ikeda, Shoji; Ohno, Hideo

    2013-07-01

    We investigate the magnetic properties of CoNi and CoPt films prepared by an alternate monoatomic layer deposition and discuss the possible existence of a metastable superlattice structure. We find that, as has been reported for the CoPt and CoPd films, the CoNi film also exhibits a perpendicular magnetic anisotropy when the monoatomic Co and Ni layers are stacked alternately, suggesting the possible formation of superlattice structure. Since the CoNi film contains neither noble nor rare-earth metals, it should be an attractive material system for applications.

  17. Nanostructured nickel oxide films prepared by chemical vapor deposition and their electrochromic properties.

    PubMed

    Vargas Garcia, J R; Lazcano Ugalde, E M; Hernandez Santiago, F; Hallen Lopez, J M

    2008-05-01

    The influence of the deposition conditions on the structural features and electrochromic properties of nickel oxide (NiO) films prepared by chemical vapor deposition has been investigated. NiO films have been prepared on fluorine doped tin oxide (FTO) coated glass substrates from nickel-acetylacetonate precursor and their electrochromic properties have been studied by cyclic voltammetry in a 0.1 M KOH solution at room temperature. Films exhibiting only the NiO phase were obtained at deposition temperatures higher than 450 degrees C in a wide range of reactor pressures (0.13 to 66.6 kPa). Particularly, NiO films prepared at 500-550 degrees C from 0.13 to 53.3 kPa are transparent in nature and exhibit a crystallite size varying from 10 to 60 nm. An appreciable anodic electrochromic change from transparent to black coloured resulted from a very porous surface morphology and film thickness of about 3.5 microm. The electrochromic change was maintained over 3000 switching cycles. Nanostructured 3.5 microm-thick NiO films showed a maximum difference in optical transmittance of about 40% in the near-infrared region. These results make the nanostructured NiO films comparables with those prepared by other deposition techniques.

  18. Preparation Of Electrochromic Metal Oxide Films By Plasma-Enhanced Chemical Vapor Deposition

    NASA Astrophysics Data System (ADS)

    Benson, D. K.; Tracy, C. E.; Svensson, J. S. E. M.; Liebert, B. E.

    1987-11-01

    Laboratory procedures have been developed for depositing thin films of electrochromic metal oxides by plasma-enhanced chemical vapor deposition (PE-CVD). In this process, vapor phase reactants, such as tungsten hexafluotIde, are mixed with oxygen and excited by RF energy at a frequency of 13.56 MHz and power levels up to≍1W/cm2 substrate area. Large rates of oxide deposition have been achieved (> 8 nm/s) making this process a candidate for high-speed coating of large area substrates, such as window glass. Amorphous WO1 films prepared by PE-CVD have been shown to have electrochromic responses virtually identical to films prepared by vacuum evaporation. The lithium ion diffusion rate, for example, is approximately 1.3 x 10-11 cm2 /s at x = 0.03 in LixWO3 prepared by PE-CVD. On the other hand, molybdenum oxide films and mixed molybdenum/tungsten oxide films prepared by PE-CVD from the hexafluorides differ markedly from vacuum evaporated films. Their electrochromic responses are spectrally different and are much slower. Lithium ion diffusion rates in such Mo03 films are lower by about three orders of magnitude. These differences are tentatively attributed to a large fraction of fluorine (Mo:F ratios of the order of 2:1) which are incorporated into the molybdenum and mixed oxides, but are not incorporated into the tungsten oxides.

  19. Process Condition Considered Preparation and Characterization of Plasma Polymerized Methyl Methacrylate Thin Films for Organic Thin Film Transistor Application

    NASA Astrophysics Data System (ADS)

    Lee, Se-Hyun; Lee, Boong-Joo; Lim, Young-Taek; Lim, Jae-Sung; Lee, Sunwoo; Ochiai, Shizuyasu; Yi, Jun-Sin; Shin, Paik-Kyun

    2012-02-01

    Plasma polymerized methyl methaclylate (ppMMA) thin films were prepared with various process conditions such as inductively coupled plasma (ICP) power, substrate bias power, working pressure, substrate heating temperature, substrate position, and monomer flow rate. Thickness, surface morphology, dielectric constant, and leakage current of the ppMMA thin films were investigated for application to organic thin film transistor as gate dielectric. Deposition rate of over 8.6 nm/min, dielectric constant of 3.4, and leakage current density of 8.9 ×10-9 A/cm-2 at electric field of 1 MV/cm were achieved for the ppMMA thin film prepared at the optimized process condition: plasma power of RF 100 W; Ar flow rate of 20 sccm; working pressure of 5 mTorr; substrate temperature of 100 °C substrate position of 100 mm. The ppMMA thin film was then applied to pentacene based organic thin film transistor (OTFT) device fabrication. The OTFT device with 80 nm thick pentacene semiconductor layer showed field effect mobility of 0.144 cm2 V-1 s-1 and threshold voltage of -1.72 V.

  20. Preparation of silver-activated zinc sulfide thin films

    NASA Technical Reports Server (NTRS)

    Feldman, C.; Swindells, F. E.

    1968-01-01

    Silver improves luminescence and reduces contamination of zinc sulfide phosphors. The silver is added after the zinc sulfide phosphors are deposited in thin films by vapor evaporation, but before calcining, by immersion in a solution of silver salt.

  1. PLD prepared nanostructured Pt-CeO2 thin films containing ionic platinum

    NASA Astrophysics Data System (ADS)

    Vorokhta, M.; Khalakhan, I.; Matolínová, I.; Nováková, J.; Haviar, S.; Lančok, J.; Novotný, M.; Yoshikawa, H.; Matolín, V.

    2017-02-01

    The composition of nanostructured Pt-CeO2 films on graphite substrates prepared by pulsed laser deposition has been investigated by means of hard X-ray photoelectron spectroscopy, scanning electron microscopy, high resolution transmission electron microscopy, and atomic force microscopy. The influence of morphology of the graphite substrates was investigated with respect to the relative concentrations of ionic and metallic Pt species in the films. It was found that the degree of Pt2+ enrichment is directly related to the surface morphology of graphite substrates. In particular, the deposition of Pt-CeO2 films on rough graphite substrate etched in oxygen plasma yielded nanostructured Pt-CeO2 catalyst films with high surface area and high Pt2+/Pt0 ratio. The presented results demonstrate that PLD is a suitable method for the preparation of thin Pt-CeO2 catalyst films for fuel cell applications.

  2. Method for the preparation of nanocrystalline diamond thin films

    DOEpatents

    Gruen, Dieter M.; Krauss, Alan R.

    1998-01-01

    A method and system for manufacturing nanocrystalline diamond film on a substrate such as field emission tips. The method involves forming a carbonaceous vapor, providing a gas stream of argon, hydrocarbon and possibly hydrogen, and combining the gas with the carbonaceous vapor, passing the combined carbonaceous vapor and gas carrier stream into a chamber, forming a plasma in the chamber causing fragmentation of the carbonaceous vapor and deposition of a diamond film on the field emission tip.

  3. Method for the preparation of nanocrystalline diamond thin films

    DOEpatents

    Gruen, D.M.; Krauss, A.R.

    1998-06-30

    A method and system are disclosed for manufacturing nanocrystalline diamond film on a substrate such as field emission tips. The method involves forming a carbonaceous vapor, providing a gas stream of argon, hydrocarbon and possibly hydrogen, and combining the gas with the carbonaceous vapor, passing the combined carbonaceous vapor and gas carrier stream into a chamber, forming a plasma in the chamber causing fragmentation of the carbonaceous vapor and deposition of a diamond film on the field emission tip. 40 figs.

  4. Preparation and Characterization of Large Area Monolayer Films of Pt Nanoparticles

    NASA Astrophysics Data System (ADS)

    Kelly, Brian; Cichocki, Ronald; Ren, Jie; Schmidt, Robert; Theopold, Klaus; Unruh, Karl

    Highly uniform monolayer thick coatings of Pt nanoparticles with areas as large as 20 cm2 have been prepared by first self-assembling the desired Pt film at the interface between two immiscible liquids and then transferring the film to a glass substrate. The controlled addition of ethyl alcohol to a phase separated mixture of an aqueous colloidal solution of Pt nanoparticles and hexane allowed both monolayer and multilayer films to be prepared. Optical microscopy and UV-vis spectrophotometry measurements have been used to verify the large scale uniformity of the coatings while transmission electron and atomic force microscopy measurements confirmed that single and multilayer films can be prepared. This material is based upon work supported by the National Science Foundation under Grant No. 1410076.

  5. Improved optical transparency of cuo films prepared by using quantum-dot ink on glass substrates

    NASA Astrophysics Data System (ADS)

    Khan, Rizwan; Yun, Jin Hyeon; Lee, In-Hwan; Vaseem, Mohammad; Hahn, Yoon Bong

    2016-01-01

    The present investigation reports a simple solution process for synthesizing CuO quantum dots at low temperature without using surfactants or templates. Detailed structural characterizations revealed that the as-prepared CuO quantum dots were uniform and dense with high crystallinity. As-prepared CuO quantum dots were used as an ink to prepare CuO films on glass substrates via a spin-coating method. The effects of annealing temperature on the optical properties of CuO films were investigated. The optical transparency of the CuO films showed an improved transmittance of > 80% at a wave length of 800 nm after annealing at 300 °C. In addition, the band-gap energy was observed to decrease from 1.70 to 1.28 eV with increasing annealing temperature from 300 to 500 °C due to the improvement in the crystallinity with grain growth in the films.

  6. Preparation and thermochromic properties of Ce-doped VO{sub 2} films

    SciTech Connect

    Song, Linwei; Zhang, Yubo; Huang, Wanxia; Shi, Qiwu; Li, Danxia; Zhang, Yang; Xu, Yuanjie

    2013-06-01

    Graphical abstract: This effect of doping concentration on the phase transition temperature of VO{sub 2} films demonstrates that the phase transition temperature is decreasing along with the increase of the Ce dopant concentrations. After doping Ce, the transition temperature of VO{sub 2} film changes appreciably. Highlights: ► Ce-doped VO{sub 2} films were prepared on muscovite substrate by inorganic sol–gel method for the first time. ► The cerium existing in the VO{sub 2} films in the form of Ce{sup 4+} and Ce{sup 3+} was substituted for part of V atoms in the lattice. ► Ce doping could remarkably reduce the particle size of the Ce-doped films compared with undoped films. ► The phase transition temperature of Ce-doped VO{sub 2} films decreased appreciably with maintaining high-quality phase transition. - Abstract: Mixture of cerium (III) nitrate hexahydrate and vanadium pentaoxide powder were used as precursor to prepare Ce-doped VO{sub 2} films on the muscovite substrate by inorganic sol–gel method. SEM, XRD and XPS were used to investigate the morphologies and structures of VO{sub 2} films. The results show that the VO{sub 2} films grow on the muscovite substrate with preferred orientated (0 1 1) plane and the Ce exists in the form of Ce{sup 4+} and Ce{sup 3+} replacing part of V atoms in the lattice. The infrared transmittance change was measured from room temperature to the temperature above the metal–insulator transition. The films have excellent thermochromic performance. The metal–insulator transition temperature of VO{sub 2} films changes appreciably with Ce doped, which decreases by 4.5 °C per 1 at.% doping. Furthermore, Ce doping could remarkably reduce the particle size of VO{sub 2} films.

  7. High-mobility ultrathin semiconducting films prepared by spin coating.

    PubMed

    Mitzi, David B; Kosbar, Laura L; Murray, Conal E; Copel, Matthew; Afzali, Ali

    2004-03-18

    The ability to deposit and tailor reliable semiconducting films (with a particular recent emphasis on ultrathin systems) is indispensable for contemporary solid-state electronics. The search for thin-film semiconductors that provide simultaneously high carrier mobility and convenient solution-based deposition is also an important research direction, with the resulting expectations of new technologies (such as flexible or wearable computers, large-area high-resolution displays and electronic paper) and lower-cost device fabrication. Here we demonstrate a technique for spin coating ultrathin (approximately 50 A), crystalline and continuous metal chalcogenide films, based on the low-temperature decomposition of highly soluble hydrazinium precursors. We fabricate thin-film field-effect transistors (TFTs) based on semiconducting SnS(2-x)Se(x) films, which exhibit n-type transport, large current densities (>10(5) A cm(-2)) and mobilities greater than 10 cm2 V(-1) s(-1)--an order of magnitude higher than previously reported values for spin-coated semiconductors. The spin-coating technique is expected to be applicable to a range of metal chalcogenides, particularly those based on main group metals, as well as for the fabrication of a variety of thin-film-based devices (for example, solar cells, thermoelectrics and memory devices).

  8. Preparation and evaluation of thin-film sodium tungsten bronzes

    NASA Technical Reports Server (NTRS)

    Kautz, H. E.; Fielder, W. L.; Singer, J.; Fordyce, J. S.

    1974-01-01

    Thin films of sodium tungsten bronze (NaxWO3) were investigated as reversible sodium ion electrodes for solid electrolytes. The films were made by electron beam evaporation of the three phases, W metal, Na2WO4, and WO3, followed by sintering. The substrates were sodium beta alumina disks and glass slides. X-ray diffraction analyses of the films showed that sintering in dry nitrogen with prior exposure to air lead to mixed phases. Sintering in vacuum with no air exposure produced tetragonal I bronze with a nominal composition of Na0.31WO3, single phase within the limits of X-ray diffraction detectability. The films were uniform and adherent on sodium beta alumina substrates. The ac and dc conductivities of the beta alumina were measured with the sodium tungsten bronze films as electrodes. These experiments indicated that the tetragonal I bronze electrodes were not completely reversible. This may have resulted from sodium ion blocking within the bronze film or at the bronze beta alumina interface. Methods for attempting to make more completely reversible electrodes are suggested.

  9. High-mobility ultrathin semiconducting films prepared by spin coating

    NASA Astrophysics Data System (ADS)

    Mitzi, David B.; Kosbar, Laura L.; Murray, Conal E.; Copel, Matthew; Afzali, Ali

    2004-03-01

    The ability to deposit and tailor reliable semiconducting films (with a particular recent emphasis on ultrathin systems) is indispensable for contemporary solid-state electronics. The search for thin-film semiconductors that provide simultaneously high carrier mobility and convenient solution-based deposition is also an important research direction, with the resulting expectations of new technologies (such as flexible or wearable computers, large-area high-resolution displays and electronic paper) and lower-cost device fabrication. Here we demonstrate a technique for spin coating ultrathin (~50Å), crystalline and continuous metal chalcogenide films, based on the low-temperature decomposition of highly soluble hydrazinium precursors. We fabricate thin-film field-effect transistors (TFTs) based on semiconducting SnS2-xSex films, which exhibit n-type transport, large current densities (>105Acm-2) and mobilities greater than 10cm2V-1s-1-an order of magnitude higher than previously reported values for spin-coated semiconductors. The spin-coating technique is expected to be applicable to a range of metal chalcogenides, particularly those based on main group metals, as well as for the fabrication of a variety of thin-film-based devices (for example, solar cells, thermoelectrics and memory devices).

  10. Methods for preparing colloidal nanocrystal-based thin films

    DOEpatents

    Kagan, Cherie R.; Fafarman, Aaron T.; Choi, Ji-Hyuk; Koh, Weon-kyu; Kim, David K.; Oh, Soong Ju; Lai, Yuming; Hong, Sung-Hoon; Saudari, Sangameshwar Rao; Murray, Christopher B.

    2016-05-10

    Methods of exchanging ligands to form colloidal nanocrystals (NCs) with chalcogenocyanate (xCN)-based ligands and apparatuses using the same are disclosed. The ligands may be exchanged by assembling NCs into a thin film and immersing the thin film in a solution containing xCN-based ligands. The ligands may also be exchanged by mixing a xCN-based solution with a dispersion of NCs, flocculating the mixture, centrifuging the mixture, discarding the supernatant, adding a solvent to the pellet, and dispersing the solvent and pellet to form dispersed NCs with exchanged xCN-ligands. The NCs with xCN-based ligands may be used to form thin film devices and/or other electronic, optoelectronic, and photonic devices. Devices comprising nanocrystal-based thin films and methods for forming such devices are also disclosed. These devices may be constructed by depositing NCs on to a substrate to form an NC thin film and then doping the thin film by evaporation and thermal diffusion.

  11. [Characterization of Nd Doped Films Prepared by Femtosecond Pulsed Laser Deposition].

    PubMed

    Yang, Xian-heng; Feng, Guo-ying; Yi, Jia-yu; Wang, Shu-tong; Zhou, Shou-huan

    2015-09-01

    Thin films of Nd:YAG and Nd:Glass were prepared on Si(100) substrate by pulsed laser deposition technology. The morphology of film surface and cross section, composition, absorption spectrum and photoluminescence (PL) spectra of films were investigated by scanning electron microscope (SEM), energy disperse spectroscopy (EDS), Fourier transform infrared spectrometer (FTIR), optical parametric oscillator (OPO) and grating spectrometer. The results show that both Nd:YAG films and Nd:Glass films grown on the substrates at room temperature are amorphous. Nd:YAG films grown by PLD contain Nd element with 0.15 at. % stoichiometric proportion. The absorption spectrum of bulk Nd:YAG target rather than deposited films exhibit two absorption peaks at 750 and 808 nm. There are no evident peaks in the photoluminescence spectra curve of Nd:YAG films. However, the photoluminescence spectra of Nd:Glass films with two sharp peaks at the wavelength of 877 and 1064 nm are observed. It indicates that Nd is doped into glass host as optically active Nd(3+) ions when Nd:Glass films grow at room temperature. But for Nd:YAG films, Nd don't incorporate into YAG host as Nd(3+) ions.

  12. Preparation and Characterisation of Fluconazole Vaginal Films for the Treatment of Vaginal Candidiasis

    PubMed Central

    Kumar, L.; Reddy, M. S.; Shirodkar, R. K.; Pai, G. K.; Krishna, V. T.; Verma, R.

    2013-01-01

    Objective of the present study was to develop and evaluate vaginal films with essential in vitro studies. Films were developed using hydroxypropyl methylcellulose as a polymer and formulations were coded. The developed films were evaluated with Fourier transform infrared spectroscopy, drug content, viscosity, surface pH, thickness, mechanical characterisation and in vitro drug release study. Fourier transform infrared spectroscopy results confirmed that there is no chemical interaction between drug and stabilisers/excipients. The batch variation was not more than 5% for average thickness and weight of the films. The drug content for the prepared formulation was in the range of 72.32±0.18% to 94.48±0.54%. Viscosity of the formulations increased with the increase in concentration of polymer. Mechanical characterisation revealed that tensile strength and percentage elongation of the films improved as there is increase in degree of substitution of the polymer, but the values of modulus decreased which confirmed that all the prepared films are soft in nature. The in vitro study indicated that 1 and 2% concentrations of polymer are the least concentrations to control the release of drug whereas the 4% concentration of polymer is a good and more effective concentration to control the release. Only one prepared formulation released the drug by following anomalous transport whereas other film formulations released the fluconazole by following Fickian diffusion mechanism. Prepared vaginal films may be an important alternative for the treatment of vaginal candidiasis, because these prepared films suggest the benefits of controlled release of fluconazole at the site of absorption. PMID:24403660

  13. Strong composite films with layered structures prepared by casting silk fibroin-graphene oxide hydrogels

    NASA Astrophysics Data System (ADS)

    Huang, Liang; Li, Chun; Yuan, Wenjing; Shi, Gaoquan

    2013-04-01

    Composite films of graphene oxide (GO) sheets and silk fibroin (SF) with layered structures have been prepared by facile solution casting of SF-GO hydrogels. The as-prepared composite film containing 15% (by weight, wt%) of SF shows a high tensile strength of 221 +/- 16 MPa and a failure strain of 1.8 +/- 0.4%, which partially surpass those of natural nacre. Particularly, this composite film also has a high modulus of 17.2 +/- 1.9 GPa. The high mechanical properties of this composite film can be attributed to its high content of GO (85 wt%), compact layered structure and the strong hydrogen bonding interaction between SF chains and GO sheets.Composite films of graphene oxide (GO) sheets and silk fibroin (SF) with layered structures have been prepared by facile solution casting of SF-GO hydrogels. The as-prepared composite film containing 15% (by weight, wt%) of SF shows a high tensile strength of 221 +/- 16 MPa and a failure strain of 1.8 +/- 0.4%, which partially surpass those of natural nacre. Particularly, this composite film also has a high modulus of 17.2 +/- 1.9 GPa. The high mechanical properties of this composite film can be attributed to its high content of GO (85 wt%), compact layered structure and the strong hydrogen bonding interaction between SF chains and GO sheets. Electronic supplementary information (ESI) available: XPS spectrum of the SF-GO hybrid film, SEM images of lyophilized GO dispersion and the failure surface of GO film. See DOI: 10.1039/c3nr00196b

  14. Controllable preparation of fluorine-containing fullerene-like carbon film

    NASA Astrophysics Data System (ADS)

    Wang, Jia; Liang, Aimin; Wang, Fuguo; Xu, Longhua; Zhang, Junyan

    2016-05-01

    Fluorine-containing fullerene-like carbon (F-FLC) films were prepared by high frequency unipolar pulse plasma-enhanced chemical vapor deposition. The microstructures, mechanical properties as well as the tribological properties of the films were investigated. The results indicate that fullerene-like microstructures appear in amorphous carbon matrix and increase greatly with the increase of bias voltage from -600 to -1600 V. And the fluorine contents in F-FLC films also show a minor rise. In addition, the hardness enhances with the bias voltage and the outstanding elastic recovery maintains because of the formation of fullerene-like microstructures in the F-FLC films. Undoubtedly, the F-FLC film deposited under high bias voltage owns a superiorly low friction, which combines the merits of fluorinated carbon film and fullerene-like carbon film. Moreover, the film also shows a remarkable wear resistance, which is mainly attributed to the excellent mechanical properties. This study provides new insights for us to prepare fluorine-containing FLC films with good mechanical and tribological properties.

  15. Studies of thin films of Ti- Zr -V as non-evaporable getter films prepared by RF sputtering

    SciTech Connect

    Gupta, Nidhi; Jagannath,; Sharma, R. K.; Gadkari, S. C.; Muthe, K. P.; Mukundhan, R.; Gupta, S. K.

    2013-02-05

    Non-Evaporable Getter (NEG) films of the Ti-Zr-V prepared on stainless steel substrates by Radio Frequency sputtering. To observe its getter behavior at the lowest activation temperature, the sample is heated continuously at different temperatures (100 Degree-Sign C, 150 Degree-Sign C, 200 Degree-Sign C and 250 Degree-Sign C) for 2 hours. The changes of the surface chemical composition at different temperaturesare analyzed by using XPS and SEM (Scanning Electron Microscopy) techniques. The volume elemental composition of the film has been measured by energy dispersive X-ray spectroscopy (EDX). The in-situ XPS measurements of the activated getter films show the disappearance of the superficial oxide layer through the variation in the oxygen stoichiometry during thermal activation. Results of these studies show that the deposited films of Ti-Zr-V could be used as NEG to produce extreme high vacuum.

  16. thin films prepared by pulsed laser deposition on different substrates

    NASA Astrophysics Data System (ADS)

    Navasery, M.; Halim, S. A.; Dehzangi, A.; Soltani, N.; Bahmanrokh, G.; Erfani H, M.; Kamalianfar, A.; Pan, K. Y.; Chang, S. C.; Chen, S. K.; Lim, K. P.; Awang Kechik, M. M.

    2014-09-01

    Perovskite manganite La2/3Ca1/3MnO3 thin films were directly grown on MgO(100), Si(100) and glass substrates by pulsed laser deposition. From the XRD patterns, the films are found to be polycrystalline, single-phase orthorhombic. The metal-insulator transition temperature is 209 K for LCMO/MgO, 266 K for LCMO/Si and 231 K for film deposited on the glass substrate. The conduction mechanism in these films is investigated in different temperature regimes. Low-temperature resistivity data below the phase transition temperature ( T P) have been fitted with the relation , indicating that the electron-electron scattering affects the conduction of these materials. The high-temperature resistivity data ( T > T P) were explained using variable-range hopping (VRH) and small-polaron hopping (SPH) models. Debye temperature values are 548 K for LCMO/Cg, 568 K for LCMO/Si and 508 K for LCMO/MgO thin films. In all thin films, the best fitting in the range of VRH is found for 3D dimension. The density of states near the Fermi level N ( E F) for LCMO/MgO is lower due to the prominent role of the grain boundary in LCMO/MgO and increase in bending of Mn-O-Mn bond angle, which decreases the double exchange coupling of Mn3+-O2-Mn4+ and in turn makes the LCMO/MgO sample less conducting as compared to the other films.

  17. Preparation of a porcine plasma protein composite film and its application.

    PubMed

    Lee, Ji-Hyun; Song, Kyung Bin

    2015-01-01

    To use blood released from slaughtering houses, a porcine plasma protein (PPP)/nanoclay composite film was prepared. The tensile strength and elongation at break values of the PPP composite film with 5% nanoclay were 10.01 MPa and 6.55%, respectively. The PPP composite film containing 1% grapefruit seed extract (GSE) was applied to pork meat, and the populations of inoculated Escherichia coli O157:H7 and Listeria monocytogenes in the pork meat packaged with the PPP composite film decreased by 0.8 and 1.0 log CFU/g, respectively, after 7 days of storage compared to the populations of the control. In addition, thiobarbituric acid values in the pork meat packaged with the PPP composite film were less than those of the control sample during storage. These results suggest that the PPP nanocomposite film containing 1% GSE can be used as a packaging material to maintain the quality of pork meat.

  18. Preparation and physicochemical characterization of topical chitosan-based film containing griseofulvin-loaded liposomes.

    PubMed

    Bavarsad, Neda; Kouchak, Maryam; Mohamadipour, Pardis; Sadeghi-Nejad, Batool

    2016-01-01

    Griseofulvin is an antifungal drug and is available as oral dosage forms. Development of topical treatment could be advantageous for superficial fungal infections of the skin. In this study, films prepared from the incorporation of griseofulvin-loaded liposomes in chitosan film for topical drug delivery in superficial fungal infections. The properties of the films were characterized regarding mechanical properties, swelling, ability to transmit vapor, drug release, thermal behavior, and antifungal efficacy against Microsporum gypseum and Epidermophyton floccosum. The presence of liposomes led to decreased mechanical properties but lower swelling ratio. Higher amount of drug permeation and rate of flux were obtained by liposomes incorporated in films compared to liposomal formulations. Antifungal efficacy of formulations was confirmed against two species of dermatophytes in vitro. Therefore, two concepts of using vesicular carrier systems and biopolymeric films have been combined and this topical novel composite film has the potential for griseofulvin delivery to superficial fungal infections.

  19. Preparation of copper thin film mask by sputtering technique assisted by polymer mask photolithography

    NASA Astrophysics Data System (ADS)

    Pakpum, C.

    2017-06-01

    This research aims to build cheaply homemade DC magnetron sputtering system for deposit metal thin films on substrate by assist of polymer mask photolithography. The metal thin film is able to use as a hard mask for patterning transfer via chemical wet etching or plasma dry etching process and it also can be used as a metal electrode in micrometre scale. Prepared copper thin films will be measured thickness by scanning electron microscope. Crystalline structure of the thin films will be examined by x-ray diffractometer. Elemental analysis contained in the films will be determined by energy dispersive x-ray spectrometer and morphology of the films will be revealed by scanning electron microscope.

  20. Dielectric dilatometry on thin Teflon-PTFE films prepared by pulsed-laser deposition

    NASA Astrophysics Data System (ADS)

    Schwoediauer, Reinhard; Bauer-Gogonea, Simona; Bauer, Stefan; Heitz, J.; Arenholz, Enno; Baeuerle, Dieter

    1999-12-01

    Polytetrafluoroethylene (Teflon PTFE) films were grown by pulsed-laser deposition (PLD). Films prepared by ablation from press-sintered targets are found to be highly crystalline, with spherulite sizes adjustable over more than one order in magnitude by suitable thermal annealing. As revealed by dielectric dilatometry, PLD-PTFE films show characteristics remarkably similar to those of conventional PTFE, i.e. the same structural first-order phase transitions. Dielectric losses are low and indicate no tendency to film oxidation. PLD-PTFE films additionally show an excellent charge-stability, comparable and even superior to commercially available Teflon-PTFE foils. PLD-PTFE enlarges the family of Teflon materials and may thus become interesting for potential miniaturized electret devices. Furthermore, dielectric dilatometry provides an elegant means for the determination of the coefficient of thermal expansion in thin nonpolar films.

  1. Structural properties of indium tin oxide thin films prepared for application in solar cells

    SciTech Connect

    Gheidari, A. Mohammadi; Mohajerzadeh, S.; Shams-Kolahi, W.

    2005-08-11

    Indium tin oxide (ITO) thin films prepared by rf sputtering were annealed in several temperatures. The electrical, optical and structural properties of these films are systematically investigated. The post annealing of the samples lead to considerably higher electrical conductivity, better optical transparency and larger grain size for the films. In an optimum annealing temperature of 400 deg. C, we have found that a maximized conductivity of films is achieved without a remarkable loss in their transparency. The sheet resistance of 2.3 {omega}/{open_square} and average grain size of 30 nm, are the results of the optimized post processing of films. The investigation for microstructure of films investigated by X-ray diffraction measurement (XRD) shows that a preferential crystal growth toward the (2 2 2) orientation takes place when the annealing temperature increases to 400 deg. C.

  2. Gasochromic Properties of Nanostructured Tungsten Oxide Films Prepared by Sputtering Deposition

    NASA Astrophysics Data System (ADS)

    Takano, Katsuyoshi; Inouye, Aichi; Yamamoto, Shunya; Sugimoto, Masaki; Yoshikawa, Masahito; Nagata, Shinji

    2007-09-01

    The effects of surface morphology on the gasochromic properties of tungsten trioxide (WO3) films are reported. WO3 films with various crystalline structures and surface morphologies are prepared by reactive rf magnetron sputtering by adjusting the substrate temperature and oxygen concentration in a sputtering gas during deposition. Grain structures on these films were confirmed by atomic force microscopy observation. The gasochromic properties of the WO3 films coated with a palladium catalyst were examined on the basis of a change in optical transmittance with 645-nm-wavelength light in 1% hydrogen in argon gas. WO3 films with a (001) orientation show sufficient gasochromic properties for their application to fiber-optic hydrogen gas sensors. The growth of the nanocrystalline structure in the WO3 films seems to improve gasochromic properties.

  3. Preparation and characterization of biodegradable active PLA film for food packaging

    NASA Astrophysics Data System (ADS)

    Di Maio, L.; Scarfato, P.; Avallone, E.; Galdi, M. R.; Incarnato, L.

    2014-05-01

    In this work we report on the preparation and characterization of a biodegradable active PLA film (aPLA), intended for food packaging applications. The film was obtained by cast extrusion blending a commercial PLA matrix with an active system, developed in our laboratory and based on PLA microparticles containing a-tocopherol (aTCP) as natural antioxidant agent. In order to optimize the film composition and processing, the active microparticles were preliminarily characterized with the aim to evaluate their morphology (size and shape), thermal resistance and a-tocopherol content. The aPLA film, produced with a 5wt% of aTCP, was characterized in terms of performance and activity. The experimental results demonstrated that the aPLA film has mechanical, thermal, barrier and optical properties adequate for packaging applications and shows oxygen scavenging activity and prolonged exhaustion lag time, compared to pure PLA films.

  4. Preparation and physicochemical characterization of topical chitosan-based film containing griseofulvin-loaded liposomes

    PubMed Central

    Bavarsad, Neda; Kouchak, Maryam; Mohamadipour, Pardis; Sadeghi-Nejad, Batool

    2016-01-01

    Griseofulvin is an antifungal drug and is available as oral dosage forms. Development of topical treatment could be advantageous for superficial fungal infections of the skin. In this study, films prepared from the incorporation of griseofulvin-loaded liposomes in chitosan film for topical drug delivery in superficial fungal infections. The properties of the films were characterized regarding mechanical properties, swelling, ability to transmit vapor, drug release, thermal behavior, and antifungal efficacy against Microsporum gypseum and Epidermophyton floccosum. The presence of liposomes led to decreased mechanical properties but lower swelling ratio. Higher amount of drug permeation and rate of flux were obtained by liposomes incorporated in films compared to liposomal formulations. Antifungal efficacy of formulations was confirmed against two species of dermatophytes in vitro. Therefore, two concepts of using vesicular carrier systems and biopolymeric films have been combined and this topical novel composite film has the potential for griseofulvin delivery to superficial fungal infections. PMID:27429928

  5. Electrochromic Properties of Tungsten Oxide Films Prepared by Reactive Sputtering

    NASA Astrophysics Data System (ADS)

    Kim, Min Hong; Kang, Tai Young; Jung, Yu Sup; Kim, Kyung Hwan

    2013-05-01

    WO3-x thin films were deposited on induim tin oxide (ITO) glass substrates with various oxygen flow ratios from 0.55 to 0.7 by the reactive facing-target sputtering method, at a power density of 4 W/cm2 and room temperature. The structural properties of the WO3-x thin films were measured by X-ray diffractometry and Raman spectral analysis. As-deposited WO3-x thin films had an amorphous structure. In the Raman spectra, WO3-x thin films exhibited two strong peaks at 770 and 950 cm-1 attributed to the vibrations of W6+-O and W6+=O bonds, respectively. The electrochemical and optical properties of WO3-x thin films were measured by cyclic voltammetry and UV/vis spectrometry. The results showed the highest charge density at an oxygen flow ratio of 0.7 and the highest transmittance in the visible range. The maximum coloration efficiency was 30.82 cm2/C at an oxygen flow ratio of 0.7.

  6. NASA Photographer Prepares to Film a Mercury Capsule

    NASA Image and Video Library

    1959-06-21

    National Aeronautics and Space Administration (NASA) photographer Arthur Laufman sets up a camera to film a Mercury capsule that was constructed by the Lewis Research Center staff. Lewis engineers and mechanics built two of the capsules for the upcoming Big Joe launches in September 1959. Big Joe was an attempt early in Project Mercury to use a full-scale Atlas booster to simulate the reentry of a mock-up Mercury capsule without actually placing it in orbit. The Photographic Branch, referred to as the Photo Lab, was part of the center’s Technical Reports Division. Originally the group performed normal and high-speed still image and motion picture photography. The photographers documented construction, performed publicity work, created images for reports, photographed data on manometer boards, and recorded test footage. Laufman joined the Photo Lab staff in 1948 and began producing full-length technical films as a tool to educate those outside of the agency on the research being conducted at Lewis. He worked with engineers to determine proper subjects for these films and develop a script. Laufman not only filmed tests, but also supporting footage of facilities, models, and staff members. He then edited the footage and added audio, visuals, and narration. The film masters were assigned standard identification numbers and add to the Photo Lab’s catalogue.

  7. High index of refraction films for dielectric mirrors prepared by metal-organic chemical vapor deposition

    SciTech Connect

    Brusasco, R.M.

    1989-01-01

    A wide variety of metal oxides with high index of refraction can be prepared by Metal-Organic Chemical Vapor Deposition. We present some recent optical and laser damage results on oxide films prepared by MOCVD which could be used in a multilayer structure for highly reflecting (HR) dielectric mirror applications. The method of preparation affects both optical properties and laser damage threshold. 10 refs., 8 figs., 4 tabs.

  8. Preparation and Properties of Transparent Ultrathin Lanthanide-Complex Films.

    PubMed

    Li, Yali; Xu, Yang; Wang, Yige

    2016-07-25

    Highly transparent ultrathin films (UTFs) based on alternative layer-by-layer assembly of Eu- and Tb-based lanthanide complexes (LCs) and Mg-Al-layered double hydroxide (LDH) nanosheets are reported herein. UV-visible absorption and fluorescence spectroscopy showed an orderly growth of the two types of ultrathin films upon increasing the number of deposition cycles. AFM and SEM measurements indicate that the films feature periodic layered structures as well as uniform surface morphology. Luminescent investigations reveal that (LCs/LDH)n UTFs can detect Fe(3+) with relative selectivity and high sensitivity (Stern-Volmer constant KSV =8.43×10(3)  L mol(-1) ); this suggests that (LCs/LDH)n UTFs could be a promising luminescent probe for selectively sensing Fe(3+) ion.

  9. Electrochemical Evaluation of Pyrite Films Prepared by Plasma Spraying

    SciTech Connect

    Guidotti, R.A.; Reinhardt, F.W.

    1998-10-30

    Thermally activated batteries use electrodes that are typically fabricated by cold pressing of powder. In the LiSi/FeS2 system, natural (mineral) pyrite is used for the cathode. In an effort to increase the energy density and specific energy of these batteries, flame and plasma spraying to form thin films of pyrite cathodes were evaluated. The films were deposited on a 304 stainless steel substrate (current collector) and were characterized by scanning electron microscopy and x-ray dlfllaction. The films were electrochemically tested in single cells at 5000C and the petiormance compared to that of standard cells made with cold-pressed powders. The best results were obtained with material deposited by de-arc plasma spraying with a proprietq additive to suppress thermal decomposion of the pyrite.

  10. GaAs Films Prepared by RF-Magnetron Sputtering

    SciTech Connect

    L.H. Ouyang; D.L. Rode; T. Zulkifli; B. Abraham-Shrauner; N. Lewis; M.R. Freeman

    2001-08-01

    The authors reported on the optical absorption, adhesion, and microstructure of RF-magnetron sputtered films of hydrogenated amorphous and microcrystalline GaAs films for the 1 to 25 {micro}m infrared wavelength rate. Sputtering parameters which were varied include sputtering power, temperature and pressure, and hydrogen sputtering-gas concentration. TEM results show a sharp transition from purely amorphous GaAs to a mixture of microcrystalline GaAs in an amorphous matrix at 34 {+-} 2 C. By optimizing the sputtering parameters, the optical absorption coefficient can be decreased below 100 cm{sup -1} for wavelengths greater than about 1.25 {micro}m. These results represent the lowest reported values of optical absorption for sputtered films of GaAs directly measured by spectrophotometry for the near-infrared wavelength region.

  11. Standard Operating Procedure for the Preparation of Lead-Containing Paint Films and Lead-in-Paint Diagnostic Test Materials

    EPA Science Inventory

    This SOP describes the preparation of stand-alone, lead paint films, prepared according to the old paint recipes. Further, this SOP describes the use of these paint films for the preparation of simulated old paints on a variety of substrates. Substrates used included wood, stee...

  12. Standard Operating Procedure for the Preparation of Lead-Containing Paint Films and Lead-in-Paint Diagnostic Test Materials

    EPA Science Inventory

    This SOP describes the preparation of stand-alone, lead paint films, prepared according to the old paint recipes. Further, this SOP describes the use of these paint films for the preparation of simulated old paints on a variety of substrates. Substrates used included wood, stee...

  13. [Research on the polycrystalline CdS thin films prepared by close-spaced sublimation].

    PubMed

    Yang, Ding-Yu; Xia, Geng-Pei; Zheng, Jia-Gui; Feng, Liang-Huan; Cai, Ya-Ping

    2009-01-01

    In the present paper, the factors of influence on the deposition rate of CdS films prepared by close-spaced sublimation (CSS) were first studied systematically, and it was found from the experiments that the deposition rate increased with the raised temperature of sublimation source, while decreased with the raised substrate temperature and the deposition pressure. The structure, morphology and light transmittance of the prepared samples were tested subsequently, and the results show: (1) The CdS films deposited under different oxygen partial pressure all present predominating growth lattice orientation (103), and further more the films will be strengthened after annealed under CdCl2 atmosphere. (2) The AFM images of CdS show that the films are compact and uniform in grain diameter, and the grain size becomes larger with the increased substrate temperature. Along with it, the film roughness was also augmented. (3) The transmittance in the shortwave region of visible light through the CdS films would be enhanced when its thickness is reduced, and that will help improve the shortwave spectral response of CdTe solar cells. Finally, the prepared CdS films were employed to fabricate CdTe solar cells, which have achieved a conversion efficiency of 10.29%, and thus the feasibility of CSS process in the manufacture of CdTe solar cells was validated primarily.

  14. Preparation of ibuprofen-loaded chitosan films for oral mucosal drug delivery using supercritical solution impregnation.

    PubMed

    Tang, Chuan; Guan, Yi-Xin; Yao, Shan-Jing; Zhu, Zi-Qiang

    2014-10-01

    Drug-loaded chitosan films suitable for oral mucosal drug delivery were prepared using supercritical solution impregnation (SSI) technology. Firstly, chitosan films were obtained via casting method, and the film properties including water-uptake, erosion and mucoadhesive were characterized. SSI process was then employed to load the drug of ibuprofen onto the prepared chitosan films, and the effects of impregnation pressure and temperature on morphologies of the ibuprofen-loaded chitosan films and drug loading capacity (DLC) were studied. The SEM and X-ray diffraction patterns suggested that distinct ibuprofen shapes such as microparticles, flake, rod-like and needle-like occurred after impregnation at different pressures, and DLC varied from 7.9% to 130.4% during the SSI process. The ex vivo release profiles showed that ibuprofen-loaded chitosan films could deliver the drug across the rabbit buccal mucosa, and up to 70% of the ibuprofen was released from the matrix in 460 min. SSI process is a promising method to prepare drug-loaded film formulations for oral mucosal drug delivery, which provides the advantages of low solvent residual and sustained- and controlled- release behavior.

  15. Preparation of conductive PDDA/(PEDOT:PSS) multilayer thin film: influence of polyelectrolyte solution composition.

    PubMed

    Jurin, F E; Buron, C C; Martin, N; Filiâtre, C

    2014-10-01

    Self-assembled multilayer films made of PEDOT:PSS poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) and PDDA poly(diallyldimethylammonium chloride) were prepared using layer-by-layer method. In order to modify the growth regime of the multilayer, to fabricate an electrical conductive film and to control its thickness, the effects of pH, type of electrolyte, ionic strength and polyelectrolyte concentration were investigated. Optical reflectometry measurements show that the pH of the solutions has no effect on the film growth while the adsorbed amount increases more rapidly when BaCl2 is used instead of NaCl as electrolyte. An increase in the ionic strength (with NaCl) induces a change in the growth regime from a linear to an exponential one at low polyelectrolyte concentration. As UV-vis measurements indicate, no decomplexation of PEDOT was recorded after film preparation. With polyelectrolyte concentration below 1 g L(-1), no conductive films were obtained even if 50 bilayers were deposited. A conductive film was prepared with a polyelectrolyte concentration of 1 g L(-1) and the measured conductivity was 0.3 S m(-1). A slight increase in conductivity was recorded when BaCl2 was used probably due to a modification of the film structure. Copyright © 2014 Elsevier Inc. All rights reserved.

  16. Study on nitrogenated amorphous carbon films prepared by unbalanced magnetron sputtering

    SciTech Connect

    Shi, J.R.

    2006-02-01

    Nitrogenated amorphous carbon (a-CN{sub x}) films were prepared by unbalanced magnetron sputtering (UBMS) at different N{sub 2}/Ar gas flow rate ratios and different bias voltages. The films were characterized using x-ray photoelectron spectroscopy, Raman scattering, nanoindenter, atomic force microscopy nanoscratch, and contact angle measurement. It was found that a negative bias of 150 V is the optimal condition for the formation of sp{sup 3} bonded carbon atoms. As the N{sub 2}/Ar flow rate ratio changes from 0 to 0.47, the nitrogen to carbon ratio in deposited films increases from 0 to 0.22, and the sp{sup 3} fraction of carbon atoms decreases from 0.51 to 0.28. The pure carbon film has the highest sp{sup 3} faction of carbon atoms and therefore the highest hardness and the lowest scratching depth. Comparing to the films prepared by conventional magnetron sputtering, all the a-CN{sub x} films prepared by UBMS show a lower scratching depth. The a-CN{sub x} films have a hydrophilic characteristic with a surface free energy from 56.6 to 65.6 mN/m and a predominant polar component.

  17. Densification and crystallization of zirconia thin films prepared by sol-gel processing

    SciTech Connect

    Schwartz, R.W.; Voigt, J.A.; Buchheit, C.D.; Boyle, T.J.

    1993-12-31

    We have investigated the effects of precursor nature and heat treatment schedule on the densification and crystallization behavior of sol-gel derived zirconia thin films. Precursor solutions were prepared from n-propanol, zirconium (IV) n-propoxide, and either acetic acid, or 2,4-pentanedione (acac) and water additions. By controlling the ligand type and ligand-to-metal ratio, we were able to prepare films which displayed significant differences in densification behavior. We attribute the dissimilarity in densification to variations in the nature of the as-deposited films, as influenced by ligand type and concentration. While the acac- derived film was a physical gel, (i.e., a physical aggregation of the oligomeric species), the acetic acid-derived film, which exhibited less consolidation, was a chemical gel that could not be redissolved in the parent solvent. Films prepared with large acac/metal ratios and small water additions exhibited minimal crosslinking at 25{degree}C, displayed the greatest consolidation ({approximately}86% shrinkage) and the highest refractive index (n = 2.071) when heat treated. These results indicate the importance that M-O-M bonds (crosslinks) formed at low temperature can have on densification behavior. We also report on the effects of heat-treatment schedules and ramp rates on densification behavior. All of the films of the present study crystallized into the cubic phase, at temperatures ranging from {approximately}400{degree}C to greater than 700{degree}C, depending on the heating rate.

  18. Characterization of sol-gel-prepared Ti02 thin film for O2 sensing

    NASA Astrophysics Data System (ADS)

    Atashbar, Massood Z.; Ghantasala, Muralihar K.; Wlodarski, Wojtek

    1997-11-01

    This paper presents the results of our investigation on deposition and characterization of sol-gel prepared TiO2 thin films for oxygen sensing applications. The properties of pure TiO2 thin films are compared with those doped with niobium oxide and 1%pt. These films are characterized using Rutherford backscattering spectroscopy (RBS), x-ray diffraction (XRD) and scanning electron microscopy (SEM) to study their chemical composition, structure and surface morphology respectively. Both kinds of the films are stoichiometric. Pure TiO2 as well as doped films were amorphous as deposited. Pure TiO2 films after annealing to 450 degrees Celsius and above showed the formation of anatase phase, while the doped films still predominantly amorphous, barely showing the onset of crystallinity. Pure films after annealing to 600 degrees Celsius appear to have become granular and porous. Doping with niobium oxide and Pt resulted in modification of film microstructure also. As a result of doping, the gas sensitivity of the films is increased from 8 to 24 and operating temperature decreased from 320 degrees Celsius to 190 degrees Celsius.

  19. Thermally induced superhydrophilicity in TiO2 films prepared by supersonic aerosol deposition.

    PubMed

    Park, Jung-Jae; Kim, Do-Yeon; Latthe, Sanjay S; Lee, Jong-Gun; Swihart, Mark T; Yoon, Sam S

    2013-07-10

    Superhydrophilic and superhydrophobic surfaces enable self-cleaning phenomena, either forming a continuous water film or forming droplets that roll off the surface, respectively. TiO2 films are well-known for their extreme hydrophilicity and photocatalytic characteristics. Here, we describe nanostructured TiO2 thin films prepared by supersonic aerosol deposition, including a thorough study of the effects of the annealing temperature on the crystal structure, surface morphology, surface roughness, and wetting properties. Powder X-ray diffraction showed that supersonic deposition resulted in fragmentation and amorphization of the micrometer-size anatase (60%)-rutile (40%) precursor powder and that, upon annealing, a substantial fraction of the film (~30%) crystallized in the highly hydrophilic but metastable brookite phase. The film morphology was also somewhat modified after annealing. Scanning electron microscopy and atomic force microscopy revealed rough granular films with high surface roughness. The as-deposited TiO2 films were moderately hydrophilic with a water contact angle (θ) of ~45°, whereas TiO2 films annealed at 500 °C became superhydrophilic (θ ~ 0°) without UV illumination. This thermally induced superhydrophilicity of the TiO2 films can be explained on the basis of the combined effects of the change in the crystal structure, surface microstructure, and surface roughness. Supersonic aerosol deposition followed by annealing is uniquely able to produce these nanostructured films containing a mixture of all three TiO2 phases (anatase, rutile, and brookite) and exhibiting superhydrophilicity without UV illumination.

  20. Preparation of pectin/silver nanoparticles composite films with UV-light barrier and properties.

    PubMed

    Shankar, Shiv; Tanomrod, Nattareya; Rawdkuen, Saroat; Rhim, Jong-Whan

    2016-11-01

    Silver nanoparticles (AgNPs) was synthesized by a green method using an aqueous extract of Caesalpinia mimosoides Lamk (CMLE) as reducing and stabilizing agents, and they were used for the preparation of pectin-based antimicrobial composite films. The AgNPs were spherical in shape with the size in the range of 20-80nm and showed the absorption peak around 500nm. The pectin/AgNPs composite film exhibited characteristic absorption peak of AgNPs at 480nm. The surface color and light transmittance of the pectin films were greatly influenced by the addition of AgNPs. The lightness of the films decreased, however, redness and yellowness of the films increased after incorporation of AgNPs. UV-light barrier property of the pectin film increased significantly with a little decrease in the transparency. Though there were no structural changes in the pectin film by the incorporation of CMLE and AgNPs as indicated by the FTIR results, the film properties such as thermal stability, mechanical strength, and water vapor barrier properties of the pectin films increased. The pectin/AgNPs nanocomposite films exhibited strong antibacterial activity against food-borne pathogenic bacteria, Escherichia coli and Listeria monocytogenes. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Study on the Preparation and Properties of Colored Iron Oxide Thin Films

    NASA Astrophysics Data System (ADS)

    Zhao, Xianhui; Li, Changhong; Liu, Qiuping; Duan, Yandong; He, Junjing; Liu, Su; Wang, Hai; Liang, Song

    2013-03-01

    Colored iron oxide thin films were prepared using Sol-gel technique. The raw materials were tetraethyl orthosilicate (TEOS), etoh ehanol (EtOH), iron nitrate, and de-ionized water. Various properties were measured and analysed, including the colour of thin films, surface topography, UV-Visible spectra, corrosion resistance and hydrophobicity. To understand how these properties influenced the structural and optical properties of Fe2O3 thin films, Scanning Electron Microscope (SEM), UV Spectrophotometer and other facilities were employed. Many parameters influence the performance of thin films, such as film layers, added H2O content, and the amount of polydimethylsiloxane (PDMS). When the volume ratio of TEOS, EtOH and H2O was 15: 13: 1, the quality of Fe(NO3)3·9H2O was 6g, and pH value was 3, reddish and uniform Fe2O3 thin films with excellent properties were produced. Obtained thin films possessed corrosion resistance in hydrochloric acid with pH=l and the absorption edge wavelength was ~350.2nm. Different H2O contents could result in different morphologies of Fe2O3 nanoparticles. When 1.5 ml PDMS was added into the Sol, thin films possessed hydrophobiliry without dropping. Coating with different layers, thin films appeared different morphologies. Meanwhile, with the increment of film layers, the absorbance increased gradually.

  2. Back-etch method for plan view transmission electron microscopy sample preparation of optically opaque films.

    PubMed

    Yao, Bo; Coffey, Kevin R

    2008-04-01

    Back-etch methods have been widely used to prepare plan view transmission electron microscopy (TEM) samples of thin films on membranes by removal of the Si substrate below the membrane by backside etching. The conventional means to determine when to stop the etch process is to observe the color of the light transmitted through the sample, which is sensitive to the remaining Si thickness. However, most metallic films thicker than 75 nm are opaque, and there is no detectable color change prior to film perforation. In this paper, a back-etch method based on the observation of an abrupt change of optical reflection contrast is introduced as a means to determine the etch endpoint to prepare TEM samples for these films. As the acid etchant removes the Si substrate material a rough interface is generated. This interface becomes a relatively smooth and featureless region when the etchant reaches the membrane (film/SiO2). This featureless region is caused by the mirror reflection of the film plane (film/SiO2 interface) through the optically transparent SiO2 layer. The lower etch rate of SiO2 (compared with Si) gives the operator enough time to stop the etching without perforating the film. A clear view of the morphology and control of Si roughness during etching are critical to this method, which are discussed in detail. The procedures of mounting wax removal and sample rinsing are also described in detail, as during these steps damage to the membrane may easily occur without appropriate consideration. As examples, the preparation of 100-nm-thick Fe-based amorphous alloy thin film and 160-nm-thick Cu-thin film samples for TEM imaging is described.

  3. Preparation of UV curing crosslinked polyviologen film and its photochromic and electrochromic performances

    NASA Astrophysics Data System (ADS)

    Gao, Li-ping; Ding, Guo-jing; Wang, Yue-chuan; Yang, Yu-lin

    2011-11-01

    Polyether urethane diacrylate matrix (PEUDA) and acrylate-functional viologen (ACV2+) were successfully synthesized and characterized in detail by FTIR and 1H NMR spectra, respectively. Subsequently, they were used to prepare UV curing crosslinked polyviologen film in combination with 2-hydroxyethyl methacrylate (HEMA), trimethylolpropane ethoxylate triacrylate (TMPTA) and diphenyl (2, 4, 6-trimethylbenzoyl) phosphine oxide (TPO). UV curing approach confined the polyviologen film on ITO electrode, which imparted the film excellent adhesion ability to ITO glass, good solvent resistance, excellent chemical stability, excellent optical and electrochemical properties. The crosslinked PACV2+ film exhibited excellent photochromic and electrochromic performances. After UV illumination for 60 s, the crosslinked PACV2+ film can swiftly change its color from pale yellow to deep blue, while the optical transmission of crosslinked PACV2+ film at 610 nm did not change significantly and still retained about 63.6% after 30 cycles. Simultaneously, the cyclic voltammetry experiment showed the PACV2+ film can undergo repeatable electrochemical redox reactions with good reversibility beyond the 10th scan. Furthermore, the electrochromic device composed of the PACV2+ film and gel electrolyte film can undergo reversible color change in response to the external voltages of -2.0 V and 2.0 V, respectively, while the contrast of EC device at 610 nm did not change significantly and still retained about 39.5% after 10 cycles. This UV curing approach to preparing viologen-functional film offers a method to preparing large-scale photo- and electrochromic device, which is relatively simple, high productivity, energy saving, and environmental protection.

  4. Properties and characterization of bionanocomposite films prepared with various biopolymers and ZnO nanoparticles.

    PubMed

    Kanmani, Paulraj; Rhim, Jong-Whan

    2014-06-15

    This study was aimed to develop biopolymer based antimicrobial films for active food packaging and to reduce environmental pollution caused by accumulation of synthetic packaging. The ZnO NPs were incorporated as antimicrobials into different biopolymers such as agar, carrageenan and CMC. Solvent casting method was performed to prepare active nanocomposite films. Methods such as FE-SEM, FT-IR and XRD were used to characterize resulting films. Physical, mechanical, thermal and antimicrobial properties were also examined. Remarkable surface morphological differences were observed between control and nanocomposite films. The crystallinity of ZnO was confirmed by XRD analysis. The addition of ZnO NPs increased color, UV barrier, moisture content, hydrophobicity, elongation and thermal stability of the films, while decreased WVP, tensile strength and elastic modulus. ZnO NPs impregnated films inhibited growth of L. monocytogenes and E. coli. So these newly prepared nanocomposite films can be used as active packaging film to extend shelf-life of food. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Preparing hydrophobic nanocellulose-silica film by a facile one-pot method.

    PubMed

    Le, Duy; Kongparakul, Suwadee; Samart, Chanatip; Phanthong, Patchiya; Karnjanakom, Surachai; Abudula, Abuliti; Guan, Guoqing

    2016-11-20

    Hydrophobic nanocellulose-silica film was successfully prepared by a facile one-pot method using tetraethoxysilane (TEOS) and dodecyl triethoxylsilane (DTES). Morphological characterization of the hydrophobic nanocellulose-silica (NC-SiO2-DTES) film showed well self-assembled DTES modified silica spherical nanoparticles with the particle sizes in the range of 88-126nm over the nanocellulose film. The hydrophobicity of the NC-SiO2-DTES film was achieved owing to the improvement of roughness of the nanocellulose film by coating dodecyl- terminated silica nanoparticles. An increase in DTES loading amount and reaction time increased the hydrophobicity of the film, and the optimum condition for NC-SiO2-DTES film preparation was achieved at DTES/TEOS molar ratio of 2.0 for 8h reaction time. Besides, the NC-SiO2-DTES film performed superoleophilic property with octane and hexadecane contact angles of 0°. It also showed an excellent hydrophobic property over all pH values ranged from 1 to 14.

  6. Preparation and characterization of microporous poly(D,L-lactic acid) film for tissue engineering scaffold.

    PubMed

    Shi, Shuai; Wang, Xiu Hong; Guo, Gang; Fan, Min; Huang, Mei Juan; Qian, Zhi Yong

    2010-11-24

    We prepared a series of microporous films based on poly(d,l-lactic acid) (PLA) via phase separation. According to scanning electron microscopy (SEM), a 3-dimensional foamy structure with multimicrometer scale pores on the air surface of film could be observed. As the morphology of PLA film could not be stabilized using solvent-nonsolvent phase separation, we investigated the effect of temperature, air movement, and concentration on the properties of microporous PLA films. The results show that when the temperature was 25°C in a vacuum, it was easy to prepare PLA film with micropores, and it was stable. As the relationship between the morphology and formation factors was clear and the morphology of the PLA film was controllable, we studied the PLA film's potential use for cell culture. SEM results showed that NIH3T3 cell could be adhered on the surface of film well after incubation for 2 days. Meanwhile, in vitro culture experiments revealed the great biocompatibility of the scaffold for adsorption and proliferation of fibroblasts.

  7. Oromucosal film preparations: points to consider for patient centricity and manufacturing processes.

    PubMed

    Krampe, Raphael; Visser, J Carolina; Frijlink, Henderik W; Breitkreutz, Jörg; Woerdenbag, Herman J; Preis, Maren

    2016-01-01

    According to the European Pharmacopoeia, oromucosal films comprise mucoadhesive buccal films and orodispersible films. Both oral dosage forms receive considerable interest in the recent years as commercially available pharmaceutical products and as small scale personalized extemporaneous preparations. In this review, technological issues such as viscosity of the casting liquid, mechanical properties of the film, upscaling and the stability of the casting solution and produced films will be discussed. Furthermore, patient-related problems like appearance, mucosal irritation, taste, drug load, safety and biopharmaceutics are described. Current knowledge and directions for solutions are summarized. The viscosity of the casting solution is a key factor for producing suitable films. This parameter is amongst others dependent on the polymer and active pharmaceutical ingredient, and the further excipients that are used. For optimal patient compliance, an acceptable taste and palatability are desirable. Safe and inert excipients should be used and appropriate packaging should be provided to produced films. Absorption through the oral mucosa will vary for each active compound, formulation and patient, which gives rise to pharmacokinetic questions. Finally, the European Pharmacopoeia needs to specify methods, requirement and definitions for oromucosal film preparations based on bio-relevant data.

  8. Method of preparing thin film polymeric gel electrolytes

    DOEpatents

    Derzon, D.K.; Arnold, C. Jr.

    1997-11-25

    Novel hybrid thin film electrolyte is described, based on an organonitrile solvent system, which are compositionally stable, environmentally safe, can be produced efficiently in large quantity and which, because of their high conductivities {approx_equal}10{sup {minus}3}{Omega}{sup {minus}1}cm{sup {minus}1} are useful as electrolytes for rechargeable lithium batteries. 1 fig.

  9. Method of preparing thin film polymeric gel electrolytes

    DOEpatents

    Derzon, Dora K.; Arnold, Jr., Charles

    1997-01-01

    Novel hybrid thin film electrolyte, based on an organonitrile solvent system, which are compositionally stable, environmentally safe, can be produced efficiently in large quantity and which, because of their high conductivities .apprxeq.10.sup.-3 .OMEGA..sup.-1 cm.sup.-1 are useful as electrolytes for rechargeable lithium batteries.

  10. Preparation of Ag-containing diamond-like carbon films on the interior surface of tubes by a combined method of plasma source ion implantation and DC sputtering

    NASA Astrophysics Data System (ADS)

    Hatada, R.; Flege, S.; Bobrich, A.; Ensinger, W.; Dietz, C.; Baba, K.; Sawase, T.; Watamoto, T.; Matsutani, T.

    2014-08-01

    Adhesive diamond-like carbon (DLC) films can be prepared by plasma source ion implantation (PSII), which is also suitable for the treatment of the inner surface of a tube. Incorporation of a metal into the DLC film provides a possibility to change the characteristics of the DLC film. One source for the metal is DC sputtering. In this study PSII and DC sputtering were combined to prepare DLC films containing low concentrations of Ag on the interior surfaces of stainless steel tubes. A DLC film was deposited using a C2H4 plasma with the help of an auxiliary electrode inside of the tube. This electrode was then used as a target for the DC sputtering. A mixture of the gases Ar and C2H4 was used to sputter the silver. By changing the gas flow ratios and process time, the resulting Ag content of the films could be varied. Sample characterizations were performed by X-ray photoelectron spectroscopy, secondary ion mass spectrometry, atomic force microscopy and Raman spectroscopy. Additionally, a ball-on-disk test was performed to investigate the tribological properties of the films. The antibacterial activity was determined using Staphylococcus aureus bacteria.

  11. A.C. Conductivity of Bi2Cu0.1V0.9O5.35 Films for Fuel Cell Application

    NASA Astrophysics Data System (ADS)

    Nimat, R. K.; Lokare, S. A.; Pawar, S. H.

    2011-07-01

    The A.C. conductivity and dielectric properties of Bi2Cu0.1V0.9O5.35 thin films were studied as a function of frequency and temperature. The A.C. conductivity of Bi2Cu0.1V0.9O5.35 film increases with frequency. The low frequency region corresponds to the D.C. conductivity where the inter-well hopping responsible for D.C. conduction completely dominates over the intra-well hopping associated with pure A.C. conduction. Higher values of A.C. conductivity for films formed on alumina substrates predict their suitability for fuel cell application

  12. A scalable colloidal approach to prepare hematite films for efficient solar water splitting.

    PubMed

    Zong, Xu; Thaweesak, Supphasin; Xu, Hongyi; Xing, Zheng; Zou, Jin; Lu, Gaoqing Max; Wang, Lianzhou

    2013-08-07

    The development of technologically and economically viable strategies for large-scale fabrication of photoelectrodes is crucial for solar H2 production from photoelectrochemical water splitting. Herein, a low-cost and facile colloidal electrophoretic deposition approach was developed for scalable fabrication of hematite (α-Fe2O3) films. Large-sized uniform films (e.g. 80 mm × 70 mm) with tailored thickness and nanostructures can be easily prepared on conductive substrates within 2 minutes. The resultant films showed a high photocurrent of ∼1.1 mA cm(-2) at 1.23 V(RHE) under standard AM 1.5G illumination, which is among the highest reported values achieved on hematite films prepared using other complex colloidal approaches. The present work will pave a new avenue for fabrication of efficient photoelectrodes toward practically viable solar H2 production.

  13. Highly transparent and conductive ZnO:Al thin films prepared by vacuum arc plasma evaporation

    NASA Astrophysics Data System (ADS)

    Miyata, Toshihiro; Minamino, Youhei; Ida, Satoshi; Minami, Tadatsugu

    2004-07-01

    A vacuum arc plasma evaporation (VAPE) method using both oxide fragments and gas sources as the source materials is demonstrated to be very effective for the preparation of multicomponent oxide thin films. Highly transparent and conductive Al-doped ZnO (AZO) thin films were prepared by the VAPE method using a ZnO fragment target and a gas source Al dopant, aluminum acethylacetonate (Al(C5H7O2)3) contained in a stainless steel vessel. The Al content in the AZO films was altered by controlling the partial pressure (or flow rate) of the Al dopant gas. High deposition rates as well as uniform distributions of resistivity and thickness on the substrate surface were obtained on large area glass substrates. A low resistivity on the order of 10-4 Ω cm and an average transmittance above 80% in the visible range were obtained in AZO thin films deposited on glass substrates. .

  14. Strong composite films with layered structures prepared by casting silk fibroin-graphene oxide hydrogels.

    PubMed

    Huang, Liang; Li, Chun; Yuan, Wenjing; Shi, Gaoquan

    2013-05-07

    Composite films of graphene oxide (GO) sheets and silk fibroin (SF) with layered structures have been prepared by facile solution casting of SF-GO hydrogels. The as-prepared composite film containing 15% (by weight, wt%) of SF shows a high tensile strength of 221 ± 16 MPa and a failure strain of 1.8 ± 0.4%, which partially surpass those of natural nacre. Particularly, this composite film also has a high modulus of 17.2 ± 1.9 GPa. The high mechanical properties of this composite film can be attributed to its high content of GO (85 wt%), compact layered structure and the strong hydrogen bonding interaction between SF chains and GO sheets.

  15. Continuous Preparation of Carbon Nanotube Film and Its Applications in Fuel and Solar Cells.

    PubMed

    Luo, Xiao Gang; Huang, Xin Xin; Wang, Xiao Xia; Zhong, Xin Hua; Meng, Xin Xin; Wang, Jian Nong

    2016-03-01

    So far, simultaneously realizing the continuous, controllable, and scalable preparation of carbon nanotube (CNT) film has remained a big challenge. Here, we report a scalable approach to continuously prepare CNT film with good control of film size and thickness. This is achieved through the layer-by-layer condensation and deposition of a cylindrical CNT assembly that is continuously produced from a floating catalyst CVD reactor on a paper strip. The promising applications of such a film are demonstrated by directly using it as an effective protecting layer for the Pt/C catalyst in proton exchange membrane fuel cells and as an efficient counter electrode material in quantum-dot-sensitized solar cells.

  16. Preparation of stable aqueous solution of keratins, and physiochemical and biodegradational properties of films.

    PubMed

    Yamauchi, K; Yamauchi, A; Kusunoki, T; Kohda, A; Konishi, Y

    1996-08-01

    A stable aqueous solution of reduced keratins was prepared by extracting the proteins from wool (Corriedale) with a mixture of urea, mercaptanol, surfactant, and water at 40-60 degrees C. Sodium dodecyl sulfate was especially effective as a surfactant, not only in promoting extraction but also in stabilizing the aqueous protein solution. The proteins had the following constants: MW, 52,000-69,000 daltons; cysteine content, 8-9 mol%; pl about 6.7. A clear film was readily prepared from a keratin solution containing glycerol. The film was insoluble in water and organic solvents including dimethyl sulfoxide. The keratin film was permeable to glucose, urea, and sodium chloride. The keratin film was degraded in vitro (by trypsin) and in vivo (by subcutaneous embedding in mice).

  17. Characteristics of zinc oxide nanorod array/titanium oxide film heterojunction prepared by aqueous solution deposition

    NASA Astrophysics Data System (ADS)

    Lee, Ming-Kwei; Hong, Min-Hsuan; Li, Bo-Wei

    2016-07-01

    The characteristics of a ZnO nanorod array/TiO2 film heterojunction were investigated. A TiO2 film was prepared on glass by aqueous solution deposition with precursors of ammonium hexafluorotitanate and boric acid at 40 °C. Then, a ZnO seed layer was prepared on a TiO2 film/glass substrate by RF sputtering. A vertically oriented ZnO nanorod array was grown on a ZnO seed layer/TiO2 film/glass substrate by aqueous solution deposition with precursors of zinc nitrate and hexamethylenetetramine (HMT) at 70 °C. After thermal annealing in N2O ambient at 300 °C, this heterojunction used as an oxygen gas sensor shows much better rise time, decay time, and on/off current ratio than as-grown and annealed ZnO nanorods.

  18. Preparation and internal stress estimation of BN films by ion mixing and vapour deposition technique

    NASA Astrophysics Data System (ADS)

    Hanaki, S.; Leng, B.; Uchida, H.

    2010-07-01

    Boron Nitride (BN) films were synthesized onto silicone wafer by depositing B metal vapour under simultaneous irradiation of N ions. Here, film thickness, ion beam energy and transport ratio (B/N) were selected as a preparation parameter and they were controlled in the range of 0.2-1μm, 0.2~2keV and 1~5, respectively. The BN films prepared were characterized using several analytical techniques and their internal stresses were estimated using Stoney's equation. From Fourier transform infrared spectroscopy, it was found that use of low energy N ions is effective for the formation of cubic BN (cBN) phase using ion mixing and vapour deposition (IVD) technique. At this condition, high compressive stress is measured and strong correlations were found among crystal structure, internal stress and Knoop hardness of BN films.

  19. Photocatalysis of zinc oxide nanotip array/titanium oxide film heterojunction prepared by aqueous solution deposition

    NASA Astrophysics Data System (ADS)

    Lee, Ming-Kwei; Lee, Bo-Wei; Kao, Chen-Yu

    2017-05-01

    A TiO2 film was prepared on indium tin oxide (ITO)/glass by aqueous solution deposition (ASD) with precursors of ammonium hexafluoro-titanate and boric acid at 40 °C. The photocatalysis of annealed TiO2 film increases with increasing growth time and decreases with increasing growth times longer than 60 min. A ZnO nanotip array was prepared on ZnO seed layer/TiO2 film/glass by aqueous solution deposition with precursors of zinc nitrate and ammonium hydroxide at 70 °C. The photocatalysis of ASD-ZnO/ASD-TiO2 film/ITO glass can be better than that of P25.

  20. Two-phase nc-TiN/a-(C,CNx) nanocomposite films: A HRTEM and MC simulation study

    NASA Astrophysics Data System (ADS)

    Guo, J.; Lu, Y. H.; Hu, X. J.; Shen, Y. G.

    2013-06-01

    The grain growth in two-phase nanocomposite Ti-Cx-Ny thin films grown by reactive close-field unbalanced magnetron sputtering in an Ar-N2 gas mixture with microstructures comprising of nanocrystalline (nc-) Ti(N,C) phase surrounded by amorphous (a-) (C,CNx) phase was investigated by a combination of high-resolution transmission electron microscopy (HRTEM) and Monte Carlo (MC) simulations. The HRTEM results revealed that amorphous-free solid solution Ti(C,N) thin films exhibited polycrystallites with different sizes, orientations and irregular shapes. The grain size varied in the range between several nanometers and several decade nanometers. Further increase of C content (up to ˜19 at.% C) made the amorphous phase wet nanocrystallites, which strongly hindered the growth of nanocrystallites. As a result, more regular Ti(C,N) nanocrystallites with an average size of ˜5 nm were found to be separated by ˜0.5-nm amorphous phases. When C content was further increased (up to ˜48 at.% in this study), thicker amorphous matrices were produced and followed by the formation of smaller sized grains with lognormal distribution. Our MC analysis indicated that with increasing amorphous volume fraction (i.e. increasing C content), the transformation from nc/nc grain boundary (GB)-curvature-driven growth to a/nc GB-curvature-driven growth is directly responsible for the observed grain growth from great inhomogeneity to homogeneity process.

  1. Cellulose Nanofibers from Softwood, Hardwood, and Tunicate: Preparation-Structure-Film Performance Interrelation.

    PubMed

    Zhao, Yadong; Moser, Carl; Lindström, Mikael E; Henriksson, Gunnar; Li, Jiebing

    2017-04-10

    This work reveals the structural variations of cellulose nanofibers (CNF) prepared from different cellulose sources, including softwood (Picea abies), hardwood (Eucalyptus grandis × E. urophylla), and tunicate (Ciona intestinalis), using different preparation processes and their correlations to the formation and performance of the films prepared from the CNF. Here, the CNF are prepared from wood chemical pulps and tunicate isolated cellulose by an identical homogenization treatment subsequent to either an enzymatic hydrolysis or a 2,2,6,6-tetramethylpiperidinyl-1-oxyl (TEMPO)-mediated oxidation. They show a large structural diversity in terms of chemical, morphological, and crystalline structure. Among others, the tunicate CNF consist of purer cellulose and have a degree of polymerization higher than that of wood CNF. Introduction of surface charges via the TEMPO-mediated oxidation is found to have significant impacts on the structure, morphology, optical, mechanical, thermal, and hydrophobic properties of the prepared films. For example, the film density is closely related to the charge density of the used CNF, and the tensile stress of the films is correlated to the crystallinity index of the CNF. In turn, the CNF structure is determined by the cellulose sources and the preparation processes. This study provides useful information and knowledge for understanding the importance of the raw material for the quality of CNF for various types of applications.

  2. Preparation of polysilsesquioxane-urethaneacrylate copolymer film reinforced with chitin nanofibers.

    PubMed

    Ifuku, Shinsuke; Ikuta, Akiko; Hosomi, Tetsuya; Kanaya, Shingo; Shervani, Zameer; Morimoto, Minoru; Saimoto, Hiroyuki

    2012-07-01

    Chitin nanofibers (CNFs) reinforced silsesquioxane-urethaneacrylate (SSQ-UA) copolymer films were prepared. CNFs-SSQ-UA nanocomposite films were highly transparent due to the filling of nanometer sized (10-20 nm) CNFs inside the hybrid organic-inorganic SSQ-UA copolymer. CNFs due to their crystalline structure drastically increased Young's moduli and the tensile strengths of the composite and decreased the thermal expansion. High thermal stability of polysilsesquioxane improved heat resistance of CNFs.

  3. High dielectric constant nickel-doped titanium oxide films prepared by liquid-phase deposition

    NASA Astrophysics Data System (ADS)

    Lee, Ming-Kwei; Yen, Chih-Feng; Fan, Cho-Han

    2014-09-01

    The electrical characteristics of nickel-doped titanium oxide films prepared by liquid-phase deposition on p-type (100) silicon substrate were investigated. The aqueous solutions of ammonium hexafluorotitanate and boric acid were used as precursors for the growth of titanium oxide films and the dielectric constant is 29. The dielectric constant can be improved to 94 by nickel doping at the thermal annealing at 700 °C in nitrous oxide.

  4. Novel preparation methods of electrical contacts in Ge Sb Te thin films

    NASA Astrophysics Data System (ADS)

    Mahmoud, Saleh T.; Ghamlouche, H.; Qamhieh, N.; Al-Shamisi, Hessa

    2007-06-01

    New preparation methods of electrical contacts have been developed to minimize their effect on Ge-Sb-Te thin films. Impedance spectroscopy technique has been used to extract the contributions of both electrical contacts and the material under investigation. Three different configurations of electrical contacts were investigated. The results show that the effect of the contacts disappears when silver paste is placed on the gold electrode only without touching and interacting with the Ge-Sb-Te film.

  5. Facile preparation of smooth perovskite films for efficient meso/planar hybrid structured perovskite solar cells.

    PubMed

    Zhang, Meng; Yu, Hua; Yun, Jung-Ho; Lyu, Miaoqiang; Wang, Qiong; Wang, Lianzhou

    2015-06-21

    Smooth organolead halide perovskite films for meso/planar hybrid structured perovskite solar cells were prepared by a simple compressed air blow-drying method under ambient conditions. The resultant perovskite films show high surface coverage, leading to a device power conversion efficiency of over 10% with an open circuit voltage up to 1.003 V merely using pristine poly(3-hexylthiophene) (P3HT) as a hole transporter.

  6. Structural and gasochromic properties of WO3 films prepared by reactive sputtering deposition

    NASA Astrophysics Data System (ADS)

    Yamamoto, S.; Hakoda, T.; Miyashita, A.; Yoshikawa, M.

    2015-02-01

    The effects of deposition temperature and film thickness on the structural and gasochromic properties of tungsten trioxide (WO3) films used for the optical detection of diluted cyclohexane gas have been investigated. The WO3 films were prepared on SiO2 substrates by magnetron sputtering, with the deposition temperature ranging from 300 to 550 °C in an Ar and O2 gas mixture. The films were characterized by scanning electron microscopy (SEM), x-ray diffraction (XRD), and Rutherford backscattering spectroscopy (RBS). The gasochromic properties of the WO3 films, coated with a catalytic Pt layer, were examined by exposing them to up to 5% cyclohexane in N2 gas. It was found that (001)-oriented monoclinic WO3 films, with a columnar structure, grew at deposition temperatures between 400 and 450 °C. Furthermore, (010)-oriented WO3 films were preferably formed at deposition temperatures higher than 500 °C. The gasochromic characterization of the Pt/WO3 films revealed that (001)-oriented WO3 films, with cauliflower-like surface morphology, were appropriate for the optical detection of cyclohexane gas.

  7. Preparation and Characterization of Hydroxypropyl Methylcellulose/Polycarbophil Mucoadhesive Blend Films Using a Mixture Design Approach.

    PubMed

    Kraisit, Pakorn; Limmatvapirat, Sontaya; Nunthanid, Jurairat; Sriamornsak, Pornsak; Luangtana-Anan, Manee

    2017-03-01

    The objectives of this study were to prepare the hydroxypropyl methylcellulose (HPMC)/polycarbophil (PC) mucoadhesive blend film and to investigate the main and interaction effect of HPMC and PC mixtures on the physicochemical and mechanical properties of blend films using a simplex lattice mixture design approach. The cubic and quadratic models were selected to analyze mucoadhesive properties in terms of work of adhesion and maximum detachment force, respectively. It was shown that HPMC/PC blend film had higher mucoadhesive properties than pure HPMC film. The suitable models for analyzing swelling index of blend films at various times were assessed. The puncture strength, % elongation and hydrophilicity of films were also examined. The pure HPMC film displayed more homogeneous and smoother structures compared with the blend film, as observed by scanning electron microscope and atomic force microscopy. Intermolecular hydrogen bonding between HPMC and PC was detected using Fourier transform infrared and X-ray diffraction. Therefore, the blend film shows high potential for use as a buccal delivery system.

  8. Amorphous Indium Selenide Thin Films Prepared by RF Sputtering: Thickness-Induced Characteristics.

    PubMed

    Han, Myoung Yoo; Park, Yong Seob; Kim, Nam-Hoon

    2016-05-01

    The influence of indium composition, controlled by changing the film thickness, on the optical and electrical properties of amorphous indium selenide thin films was studied for the application of these materials as Cd-free buffer layers in CI(G)S solar cells. Indium selenide thin films were prepared using RF magnetron sputtering method. The indium composition of the amorphous indium selenide thin films was varied from 94.56 to 49.72 at% by increasing the film thickness from 30 to 70 nm. With a decrease in film thickness, the optical transmittance increased from 87.63% to 96.03% and Eg decreased from 3.048 to 2.875 eV. Carrier concentration and resistivity showed excellent values of ≥1015 cm(-3) and ≤ 10(4) Ω x cm, respectively. The conductivity type of the amorphous indium selenide thin films could be controlled by changing the film-thickness-induced amount of In. These results indicate the possibility of tuning the properties of amorphous indium selenide thin films by changing their composition for use as an alternate buffer layer material in CI(G)S solar cells.

  9. Preparation of dilute magnetic semiconductor films by metalorganic chemical vapor deposition

    NASA Technical Reports Server (NTRS)

    Nouhi, Akbar (Inventor); Stirn, Richard J. (Inventor)

    1990-01-01

    A method for preparation of a dilute magnetic semiconductor (DMS) film is provided, wherein a Group II metal source, a Group VI metal source and a transition metal magnetic ion source are pyrolyzed in the reactor of a metalorganic chemical vapor deposition (MOCVD) system by contact with a heated substrate. As an example, the preparation of films of Cd.sub.1-x Mn.sub.x Te, wherein 0.ltoreq..times..ltoreq.0.7, on suitable substrates (e.g., GaAs) is described. As a source of manganese, tricarbonyl (methylcyclopentadienyl) maganese (TCPMn) is employed. To prevent TCPMn condensation during the introduction thereof int the reactor, the gas lines, valves and reactor tubes are heated. A thin-film solar cell of n-i-p structure, wherein the i-type layer comprises a DMS, is also described; the i-type layer is suitably prepared by MOCVD.

  10. Sugar-sensitive dendrimer films as a sacrificial layer for the preparation of freestanding multilayer films.

    PubMed

    Sato, Fumiya; Anzai, Jun-Ichi

    2017-03-01

    Multilayer thin films composed of poly(vinyl alcohol) (PVA) and phenylboronic acid-bearing poly(amidoamine) dendrimer (PBA-PAMAM) were used as a sacrificial layer for constructing freestanding polyelectrolyte films consisting of poly(styrenesulfonate) (PSS) and poly(allylamine hydrochloride) (PAH). Freestanding (PSS/PAH)15 films were successfully released from substrate by exposing composite (PVA/PBA-PAMAM)n/(PSS/PAH)15 films (n=5 and 10) to sorbitol solutions under mild conditions at pH7.0-9.0. The film release was accelerated in solutions of higher sorbitol concentrations at pH9.0 as well as in solutions with lower concentration of NaCl. The results were rationalized based on the scission of boronate ester bonds between PBA-PAMAM and PVA in the (PVA/PBA-PAMAM)n layer due to a competitive binding of sorbitol to PBA-PAMAM.

  11. The influence of precursor films on CIGS films prepared by ion beam sputtering deposition

    NASA Astrophysics Data System (ADS)

    Zhao, Jun; Fan, Ping; Liang, Guangxing; Zheng, Zhuanghao; Zhang, Dongping; Chen, Chaoming

    2013-12-01

    The CuInGa(CIG) precursor films were grown by ion beam sputtering continuously CuGa/CuIn and CuIn/CuGa, and then selenized CIG to fabricate CIGS absorber films on molybdenum substrates . They were annealed in the same vacuum chamber and under the same temperature (500°C). The CIGS thin films were characterized with X-ray diffraction (XRD), Energy dispersive spectroscopy (EDS) and scanning electron microscopy (SEM) in order to study the microstructures, composition, surface morphology, electrical properties, respectively. The results showed that the CIGS thin films appeared smooth and compact with a sequence of Mo/CuGa/CuIn/Se, which were mainly of chalcopyrite structure. The CIGS thin films got the strongest diffraction peak intensity and were with good crystalline quality.

  12. Electrochromic NiO thin films prepared by spin coating

    NASA Astrophysics Data System (ADS)

    Özütok, F.; Demiri, S.; Özbek, E.

    2017-02-01

    Recently, smart windows are very important because they are often being used in smart buildings and car glasses (windows). At this point, producing effective electrochromic materials is so necessary. In this study, we produced NiO thin films by using spin coating technique on In-doped SnO2 (ITO) substrate. Nickel proportions of these nickel oxide (NiO) films are 3, 5 and 7 %. Nickel acetate tetrahydrate is the initial solution and solvents are ethylene gl ycol and n-hexzane. Structural properties and surface images are investigated by using x-ray diffactometer (XRD) and scanning electron microscope (SEM) device, respectively. In addition, electrochemical behavior is investigated by cyclic voltammetry. A correlation between surface morphology and electrochromic performance was observed as well.

  13. Method for etching thin films of niobium and niobium-containing compounds for preparing superconductive circuits

    DOEpatents

    Kampwirth, Robert T.; Schuller, Ivan K.; Falco, Charles M.

    1981-01-01

    An improved method of preparing thin film superconducting electrical circuits of niobium or niobium compounds in which a thin film of the niobium or niobium compound is applied to a nonconductive substrate, and covered with a layer of photosensitive material. The sensitive material is in turn covered with a circuit pattern exposed and developed to form a mask of the circuit in photoresistive material on the surface of the film. The unmasked excess niobium film is removed by contacting the substrate with an aqueous etching solution of nitric acid, sulfuric acid and hydrogen fluoride, which will rapidly etch the niobium compound without undercutting the photoresist. A modification of the etching solution will permit thin films to be lifted from the substrate without further etching.

  14. Method for etching thin films of niboium and niobium-containing compounds for preparing superconductive circuits

    DOEpatents

    Kampwirth, R.T.; Schuller, I.K.; Falco, C.M.

    1979-11-23

    An improved method of preparing thin film superconducting electrical circuits of niobium or niobium compounds is provided in which a thin film of the niobium or niobium compound is applied to a nonconductive substrate and covered with a layer of photosensitive material. The sensitive material is in turn covered with a circuit pattern exposed and developed to form a mask of the circuit in photoresistive material on the surface of the film. The unmasked excess niobium film is removed by contacting the substrate with an aqueous etching solution of nitric acid, sulfuric acid, and hydrogen fluoride, which will rapidly etch the niobium compound without undercutting the photoresist. A modification of the etching solution will permit thin films to be lifted from the substrate without further etching.

  15. Preparation of microstructure-controllable superhydrophobic polytetrafluoroethylene porous thin film by vacuum thermal-evaporation

    NASA Astrophysics Data System (ADS)

    Yi, Na; Bao, Shanhu; Zhou, Huaijuan; Xin, Yunchuan; Huang, Aibin; Ma, Yining; Li, Rong; Jin, Ping

    2016-09-01

    The three-dimensional porous network polytetrafluoroethylene (PTFE) thin films were achieved by a vacuum technique through evaporating the pure PTFE powders. The surfaces of PTFE thin films showed various morphologies by adjusting the evaporation temperature and the corresponding contact angle ranging from 133° to 155°. Further analyses of surface chemical composition and morphology by FTIR and FE-SEM revealed that the origin of hydrophobicity for the PTFE thin films could be ascribed to the fluorine-containing groups and the surface morphologies, indicating that abundant -CF2 groups and network structures with appropriate pore sizes played a vital role in superhydrophobicity. By characterization of UV-Vis, the films also showed high transmittance and antireflection effect. The films prepared by this simple method have potential applications such as waterproof membrane and self-cleaning coating.

  16. Preparation of γ-Al2O3 films by laser chemical vapor deposition

    NASA Astrophysics Data System (ADS)

    Gao, Ming; Ito, Akihiko; Goto, Takashi

    2015-06-01

    γ- and α-Al2O3 films were prepared by chemical vapor deposition using CO2, Nd:YAG, and InGaAs lasers to investigate the effects of varying the laser wavelength and deposition conditions on the phase composition and microstructure. The CO2 laser was found to mostly produce α-Al2O3 films, whereas the Nd:YAG and InGaAs lasers produced γ-Al2O3 films when used at a high total pressure. γ-Al2O3 films had a cauliflower-like structure, while the α-Al2O3 films had a dense and columnar structure. Of the three lasers, it was the Nd:YAG laser that interacted most with intermediate gas species. This promoted γ-Al2O3 nucleation in the gas phase at high total pressure, which explains the cauliflower-like structure of nanoparticles observed.

  17. Preparation and Structural Characterization of Superionic Conductor RbAg4I5 Crystalline Grain Film

    NASA Astrophysics Data System (ADS)

    Cao, Yang; Sun, Hong-San; Sun, Jia-Lin; Tian, Guang-Yan; Xing, Zhi; Guo, Ji-Hua

    2003-05-01

    Superionic conductor RbAg4I5 crystalline grain films were prepared by vacuum thermal evaporation on NaCl crystalline substrates. The surface morphology, microstructure and the electronic energy states of the films were examined by atomic force microscopy, transmission-electron microscopy, x-ray diffraction and x-ray photoelectron spectroscopy. The results show that the obtained RbAg4I5 layer has an epitaxial film of perfect crystalline structure, and the unit cell of crystalline grain RbAg4I5 films belongs to cubic crystal system. The principal x-ray diffraction peaks at d = 3.7447 and 1.8733 Å are related to the structure of ternary compound RbAg4I5 films.

  18. Preparation and properties of arenga starch-chitosan based edible film

    NASA Astrophysics Data System (ADS)

    Rahmawati, Putri; Ni'maturrohmah, Dwi; Luthfiana Sari, Putri; Puspita Sari, Putri; Nur Indah Sari, Tetty; Suryanti, Venti

    2016-02-01

    The main objective of this research was to prepare for edible film on the basis of arenga starch-chitosan. Carboxymethyl cellulose (CMC) was added to the blend and glycerol was used as a plasticizer. The tensile strength and water uptake of the film decreased with the increasing of glycerol content in the blend. Contrary, increasing glycerol content in the blend enhanced the elongation and swelling area of the film. The film C1, which has 6% of glycerol in the blend has a tensile strength of 124 KPa, elongation of 6.55%, swelling area of 21% and water uptake of 48%. The film C2, which has 10% of glycerol in the blend has a tensile strength of 58 KPa, elongation of 8.35%, swelling area of 32% and water uptake of 5%.

  19. Photocatalytic activity and reusability study of nanocrystalline TiO2 films prepared by sputtering technique

    NASA Astrophysics Data System (ADS)

    Barrocas, B.; Monteiro, O. C.; Jorge, M. E. Melo; Sério, S.

    2013-01-01

    The photocatalytic activity of nanocrystalline titanium dioxide (TiO2) films deposited on unheated glass substrates by DC reactive magnetron sputtering at different oxygen partial pressures was tested on the decolorization of Rhodamine 6G (Rh6G) aqueous solutions. The dye photodecolorization process was studied considering the influence of the crystallinity and preferred orientation of growth of the prepared films. It was found that the higher photocatalytic activity was achieved by the film with preferred orientation of growth along the (1 0 1) crystal direction and showing a vestigial rutile phase in a mainly anatase phase. The recycling catalytic ability of the TiO2 films was also evaluated and a promising photocatalytic performance has been revealed with a very low variation of the decay rate after five consecutive usages. Structural and morphological characterization revealed high photochemical stability of the films after successive photodegradations assays.

  20. ZnSb-based thin films prepared by ns-PLD for thermoelectric applications

    NASA Astrophysics Data System (ADS)

    Bellucci, A.; Mastellone, M.; Girolami, M.; Orlando, S.; Medici, L.; Mezzi, A.; Kaciulis, S.; Polini, R.; Trucchi, D. M.

    2017-10-01

    Zinc antimonide-based nanostructured thin films were produced by Pulsed Laser Deposition (PLD) using a ns-ArF laser (193 nm) and a multi-target deposition system. The films were prepared according to a multi-layer structure, obtained by adding different dopants (Cr, Ag) within the ZnSb matrix. The influence of the dopant introduction on the structural, compositional and electronic properties of the deposited films was studied in the temperature range 300-600 K. The power factor (PF) of films with dopant concentration of 5 at.% resulted significantly increased up to 100-200 μW/mK2 at 600 K with respect to that of undoped films.

  1. Modified sol-gel method for patterned lithium niobate thin film preparation

    NASA Astrophysics Data System (ADS)

    Poghosyan, Armen R.; Guo, Ruyan; Grigoryan, Stepan G.; Manukyan, Aleksandr L.; Vardanyan, Eduard S.

    2008-08-01

    A key stage in production of the integrated optics devices is forming of microtopography on crystalline films. The current methods generally comprise two separate steps: producing of thin film and creation a topographical pattern on it. But the inherently large chemical stability of crystalline LiNbO3 has effectively precluded the use of standard photolithographic patterning techniques. We present new approach based on the modified sol-gel technology using the photosensitive gel. In this case, the photolithography is used on the stage of dried gel whereupon the direct crystallization of patterned precursor film allows to create integrated optical element without subsequent etching of crystalline film. Presented method of patterned thin film preparation involves synthesis of photo-reactive complex of metal, which undergoes change under the UV light. This technology has allowed to obtain first samples of different types of waveguide devices.

  2. Preparation of redox polymer cathodes for thin film rechargeable batteries

    DOEpatents

    Skotheim, Terje A.; Lee, Hung S.; Okamoto, Yoshiyuki

    1994-11-08

    The present invention relates to the manufacture of thin film solid state electrochemical devices using composite cathodes comprising a redox polymer capable of undergoing oxidation and reduction, a polymer solid electrolyte and conducting carbon. The polymeric cathode material is formed as a composite of radiation crosslinked polymer electrolytes and radiation crosslinked redox polymers based on polysiloxane backbones with attached organosulfur side groups capable of forming sulfur-sulfur bonds during electrochemical oxidation.

  3. Preparation of redox polymer cathodes for thin film rechargeable batteries

    DOEpatents

    Skotheim, T.A.; Lee, H.S.; Okamoto, Yoshiyuki.

    1994-11-08

    The present invention relates to the manufacture of thin film solid state electrochemical devices using composite cathodes comprising a redox polymer capable of undergoing oxidation and reduction, a polymer solid electrolyte and conducting carbon. The polymeric cathode material is formed as a composite of radiation crosslinked polymer electrolytes and radiation crosslinked redox polymers based on polysiloxane backbones with attached organosulfur side groups capable of forming sulfur-sulfur bonds during electrochemical oxidation.

  4. Preparation of ultralow-friction surface films on vanadium diboride.

    SciTech Connect

    Erdemir, A.; Fenske, G. R.; Halter, M.

    1996-10-14

    In this paper, we present a simple annealing procedure (which we refer to as ''flash-annealing'' because of short duration) that results in the formation of an ultralow friction surface film on vanadium diboride (VB{sub 2}) surfaces. This annealing is done in a box furnace at 800 C for a period of 5 min. During annealing, the exposed surface of the VB{sub 2} undergoes oxidation and forms a layer of boron oxide (B{sub 2}O{sub 3}). In open air, the B{sub 2}O{sub 3} layer reacts spontaneously with moisture and forms a boric acid (H{sub 3}BO{sub 3}) film. The friction coefficient of a 440C steel pin against this H{sub 3}BO{sub 3} film is {approx}0.05, compared to 0.8 against the as-received VB{sub 2}. Based on Raman spectroscopy and electron microscopy studies, we elucidate the ultralow friction mechanism of the flash-annealed VB{sub 2} surfaces.

  5. Magneto-optical visualization by Bi:YIG thin films prepared at low temperatures

    SciTech Connect

    Galstyan, Ogsen; Lee, Hanju; Lee, Kiejin; Babajanyan, Arsen; Hakhoumian, Arsen; Friedman, Barry

    2015-04-28

    A device for the imaging of magnetic fields and domain structures based on the Faraday effect has been developed using garnet thin films prepared by the metal-organic decomposition method as indicators. The sensitivity was improved by using high concentration bismuth substituted yttrium iron garnet thin films with in-plane magnetic anisotropy. Low temperature synthesis of the films (Bi{sub x}Y{sub 3−x}Fe{sub 5}O{sub 12}; x = 2) on glass substrates of thickness about 0.8 μm is described and the Faraday rotation angle is measured to be about −11°/μm.

  6. Preparation of properties of SWNT/graphene oxide type flexible transparent conductive films.

    PubMed

    Kim, Jin Ho; Jung, Jae Mok; Kwak, Jun Young; Jeong, Jung Hyun; Choi, Byung Chun; Lim, Kwon Taek

    2011-08-01

    Single walled carbon nanotube (SWNT)/graphene oxide (GO) hybrid films were prepared by a facile bar coating method on a polyethylene terephthalate substrate using a mixed solution of SWCNTs and GO. An acryl type polymer was employed as a dispersion agent to obtain SWCNT and GO suspension in ethyl alcohol. The SWCNT/GO hybrid films were highly transparent and electrically conductive, showing 80% transmittance and 1.8 x 10(3) ohm/sq surface resistance. The surface resistance of the SWCNT/GO film could be further improved to 750 ohm/sq by hydrazine vapor reduction.

  7. Different properties of aluminum doped zinc oxide nanostructured thin films prepared by radio frequency magnetron sputtering

    SciTech Connect

    Bidmeshkipour, Samina Shahtahmasebi, Nasser

    2013-06-15

    Aluminium doped zinc oxide (AZO) nanostructured thin films are prepared by radio frequency magnetron sputtering on glass substrate using specifically designed ZnO target containing different amount of Al{sub 2}O{sub 3} powder as the Al doping source. The optical properties of the aluminium doped zinc oxide films are investigated. The topography of the deposited films were investigated by Atomic Force Microscopy. Variation of the refractive index by annealing temperature are considered and it is seen that the refractive index increases by increasing the annealing temperature.

  8. Preparation and characterization of pulsed laser deposition (PLD) SiC films

    NASA Astrophysics Data System (ADS)

    Tang, Y. H.; Sham, T.-K.; Yang, D.; Xue, L.

    2006-03-01

    Si K-edge XAFS was used to characterize a stoichiometric SiC film prepared by pulsed KrF laser deposition. The film was deposited on a p-type Si(1 0 0) wafer at a substrate temperature of 250 °C in high vacuum with a laser fluence of ˜5 J/cm 2. The results reveal that the film contains mainly a SiC phase with an amorphous structure in which the Si atoms are bonded to C atoms in its first shell similar to that of crystalline SiC powder but with significant disorder.

  9. Measurement of Adhesion Strength of DLC Film Prepared by Utilizing Plasma-Based Ion Implantation

    NASA Astrophysics Data System (ADS)

    Oka, Yoshihiro; Yatsuzuka, Mitsuyasu

    High-adhesion diamond-like carbon (DLC) film was prepared by a hybrid process of plasma-based ion implantation and deposition using superimposed RF and high-voltage pulses. The adhesion strength of DLC film on a stainless steel (SUS304) was enhanced by the carbon ion implantation to the substrate. Furthermore, ion implantation of mixed carbon and silicon led to considerable enhancement of adhesion strength above the resin glue strength. The adhesion strength of DLC film on the aluminum alloy (A-5052) was improved above the resin glue strength only by the carbon ion implantation to the substrate.

  10. Preparation of PbTiO3 Thin Films by Screen Printing Method

    NASA Astrophysics Data System (ADS)

    Futakuchi, Tomoaki; Tanino, Katsumi

    1994-12-01

    PbTiO3 thin films were obtained by the screen printing method on Au bottom electrodes using Si(100) substrates. The screen-printable paste was synthesized from the Pb Ti complex alkoxide and abietic acid. The optimum conditions of amount of PbO content in the paste and annealing temperature were investigated to prepare the ferroelectric thin film. The remanent polarization and coercive field of this thin film were 8 µ C/cm2 and 110 kV/cm, respectively. Pyroelectric coefficient was 0.67× 10-8 (C/cm2·K) after poling.

  11. In situ preparation of Y-Ba-Cu-O superconducting thin films by magnetron sputtering

    NASA Astrophysics Data System (ADS)

    Li, H. C.; Linker, G.; Ratzel, F.; Smithey, R.; Geerk, J.

    1988-03-01

    Thin superconducting films of YBa2Cu3O7 have been prepared by magnetron sputtering from targets of sintered material in an oxygen-argon atmosphere. The compositional and structural properties were studied by Rutherford backscattering and X-ray diffraction. The films were deposited at substrate temperatures between 580 and 800 C. It was found that the material grows in the oxygen-deficient tetragonal phase. In situ heat treatment at 430 C in pure O2 atmosphere generates the orthorhombic structure, and the films on sapphire and SrTiO3-coated sapphire substrates show the full superconducting transition at 83 K.

  12. Characterization of ZnO films prepared by sol-gel method

    NASA Astrophysics Data System (ADS)

    Zhang, Jide; Sun, Xin; Qi, Tong; Ren, Ge; Shan, Yingyu; Dong, Qingya

    2017-03-01

    The ZnO thin films were prepared on an ordinary glass substrate using an optimized Sol-gel Method. X-ray diffraction patterns indicated that the grain size increased with increasing annealing temperature. The surface morphology of the films was also analyzed by atomic force microscopy get the same result. The UV-Vis absorption spectra showed that the band edge absorption at the ZnO band edge was strong, and the band gap of the film annealed at 450 °C was 3.29eV.

  13. Antibacterial Cr-Cu-O films prepared by reactive magnetron sputtering

    NASA Astrophysics Data System (ADS)

    Musil, J.; Blažek, J.; Fajfrlík, K.; Čerstvý, R.; Prokšová, Š.

    2013-07-01

    The paper reports on the effect of Cu content in the Cr-Cu-O film and its structure on its antibacterial activity and mechanical properties. The Cr-Cu-O films were prepared by reactive magnetron sputtering from composed Cr/Cu targets using a dual magnetron. The antibacterial activity of Cr-Cu-O films was tested on the killing of Escheria coli bacteria. Correlations between the structure of the Cr-Cu-O film, the content of Cu in the film and its (i) antibacterial efficiency and (ii) mechanical properties were investigated in detail. It was found that the 100% efficiency of the killing of E. coli bacteria on the surface of the Cr-Cu-O film is achieved if (1) the Cu content in the film is ≥15 at.% and (2) the film is either X-ray amorphous or crystalline with the CuCrO2 delafossite structure. These Cr-Cu-O films need no excitation and very effectively kill E. coli bacteria in the daylight as well as in the dark. The X-ray amorphous Cr-Cu-O films with ~20 at.% Cu exhibit a higher (i) hardness H ≈ 4 GPa, (ii) effective Young's modulus E* ≈ 72 GPa and (iii) elastic recovery We ≈ 37% compared with the crystalline Cr-Cu-O film with the CuCrO2 delafossite structure exhibiting H ≈ 1.2 GPa, E* ≈ 21 GPa and We ≈ 21%. Both films very effectively kill the E. coli bacteria, however, exhibit a low ratio H/E* < 0.1.

  14. Electrochemistry of tungsten compound film prepared by liquid-phase-deposition method

    SciTech Connect

    Tada, Hiroaki

    1990-12-31

    From the viewpoint of improvement of energy efficiency in buildings, the so-called smart window with dynamic control of solar radiant energy throughput is very attractive, especially for the glass manufacturers. Several types of smart windows using chromogenic compounds have so far been proposed.among them, the electrochromic device is believed to be the most suitable for the smart window owing to its controllability of the solar transmittance as well as the memory effect. One of the key technologies to fabricate the electrochromic smart windows is to form electrochromic films with large area. The electrochromic film represented by tungsten trioxide has been prepared mainly by the physical vapor deposition methods; however, these are generally expensive and are not suitable to make a uniform and thick film over a large area. In the light of the drawbacks in the physical vapor deposition method, Baba et al. found a novel method of preparing an electrochromic tungsten compound film (TCF) by the liquid-phase-deposition method from an aqueous solution containing oxalatotungstate (V) complex. TCF has hardly been characterized, while the structure and the electrochromic properties of the tungsten trioxide films prepared by the physical vapor deposition methods have been investigated extensively. This chapter is concerned with the structure, the electrochemical properties of TCF prepared by the liquid-phase-deposition method and their correlation.

  15. Preparation of pure chitosan film using ternary solvents and its super absorbency.

    PubMed

    Wang, Xuejun; Lou, Tao; Zhao, Wenhua; Song, Guojun

    2016-11-20

    Chemical modification and graft copolymerization were commonly adopted to prepare super absorbent materials. However, physical microstructure of pure chitosan film was optimized to improve the water uptake capacity in this study. Chitosan films with micro-nanostructure were prepared by a ternary solvent system. The optimal process parameters are 1% acetic acid water solution: dioxane: dimethyl sulfoxide=90: 2.5: 7.5 (v/v/v) with chitosan concentration at 1.25% (w/v). The water uptake capacity of the chitosan film prepared under the optimal process parameters was 896g/g. The prepared chitosan films also exhibited high water uptake capacity in response to external stimuli such as temperature, pH and salt. This finding may provide another way for improving the water absorbency. The pure chitosan film may find potential applications especially in the fields of hygienic products and biomedicine due to its super water absorbency and nontoxicity. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Thin film transistor based on TiOx prepared by DC magnetron sputtering.

    PubMed

    Chung, Sung Mook; Shin, Jae-Heon; Hong, Chan-Hwa; Cheong, Woo-Seok

    2012-07-01

    This paper reports on the thin film transistor (TFT) based on TiOx prepared by direct current (DC) magnetron sputtering for the application of n-type channel transparent TFTs. A ceramic TiOx target was prepared for the sputtering of the TiO2 films. The structural, optical, and electrical properties of the TiO2 films were investigated after their heat treatment. It is observed from XRD measurement that the TiO2 films show anatase structure having (101), (004), and (105) planes after heat treatment. The anatase-structure TiO2 films show a band-gap energy of approximately 3.20 eV and a transmittance of approximately 91% (@550 nm). The bottom-gate TFTs fabricated with the TiO2 film as an n-type channel layer. These devices exhibit the on-off ratio, the field-effect mobility, and the threshold voltage of about 10(4), 0.002 cm2/Vs, and 6 V, respectively. These results indicate the possibility of applying TiO2 films depositied by DC magnetron sputtering to TiO2-based opto-electronic devices.

  17. Antimicrobial Activity of Thin Solid Films of Silver Doped Hydroxyapatite Prepared by Sol-Gel Method

    PubMed Central

    Iconaru, Simona Liliana; Chapon, Patrick; Le Coustumer, Philippe; Predoi, Daniela

    2014-01-01

    In this work, the preparation and characterization of silver doped hydroxyapatite thin films were reported and their antimicrobial activity was characterized. Silver doped hydroxyapatite (Ag:HAp) thin films coatings substrate was prepared on commercially pure Si disks by sol-gel method. The silver doped hydroxyapatite thin films were characterized by various techniques such as Scanning electron microscopy (SEM) with energy Dispersive X-ray attachment (X-EDS), Fourier transform infrared spectroscopy (FT-IR), and glow discharge optical emission spectroscopy (GDOES). These techniques have permitted the structural and chemical characterisation of the silver doped hydroxyapatite thin films. The antimicrobial effect of the Ag:HAp thin films on Escherichia coli and Staphylococcus aureus bacteria was then investigated. This is the first study on the antimicrobial effect of Ag:HAp thin films obtained by sol-gel method. The results of this study have shown that the Ag:HAp thin films with x Ag = 0.5 are effective against E. coli and S. aureus after 24 h. PMID:24523630

  18. Antimicrobial activity of thin solid films of silver doped hydroxyapatite prepared by sol-gel method.

    PubMed

    Iconaru, Simona Liliana; Chapon, Patrick; Le Coustumer, Philippe; Predoi, Daniela

    2014-01-01

    In this work, the preparation and characterization of silver doped hydroxyapatite thin films were reported and their antimicrobial activity was characterized. Silver doped hydroxyapatite (Ag:HAp) thin films coatings substrate was prepared on commercially pure Si disks by sol-gel method. The silver doped hydroxyapatite thin films were characterized by various techniques such as Scanning electron microscopy (SEM) with energy Dispersive X-ray attachment (X-EDS), Fourier transform infrared spectroscopy (FT-IR), and glow discharge optical emission spectroscopy (GDOES). These techniques have permitted the structural and chemical characterisation of the silver doped hydroxyapatite thin films. The antimicrobial effect of the Ag:HAp thin films on Escherichia coli and Staphylococcus aureus bacteria was then investigated. This is the first study on the antimicrobial effect of Ag:HAp thin films obtained by sol-gel method. The results of this study have shown that the Ag:HAp thin films with x(Ag) = 0.5 are effective against E. coli and S. aureus after 24 h.

  19. Preparation and characterization of nanostructured Pt/TiO2 thin films treated using electron beam.

    PubMed

    Shin, Joong-Hyeok; Woo, Hee-Gweon; Kim, Bo-Hye; Lee, Byung Cheol; Jun, Jin

    2010-05-01

    Pt nanoparticle-doped titanium dioxide (Pt/TiO2) thin films were prepared on a silicon wafer substrate by sol-gel spin coating process. The prepared thin films were treated with electron beam (EB at 1.1 MeV, 100, 200, 300 kGy) at air atmosphere. The effect of EB-irradiation on the composition of the treated thin films, optical properties and morphology of thin films were investigated by various analytical techniques such as X-ray photoelectron spectroscopy (XPS), spectroscopic ellipsometry (SE), X-ray diffraction (XRD), field emission-scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM). The crystal structure of the TiO2 layer was found to be an anatase phase and the size of TiO2 particles was determined to be about 13 nm. Pt nanoparticles with diameter of 5 nm were observed on surface of the films. A new layer (presumed to be Pt-Ti complex and/or PtO2 compound) was created in the Pt/TiO2 thin film treated with EB (300 kGy). The transmittance of thin film decreased with EB treatment whereas the refractive index increased.

  20. Preparation and characterization of gamma irradiated Starch/PVA/ZnO nanocomposite films

    NASA Astrophysics Data System (ADS)

    Akhavan, Azam; Khoylou, Farah; Ataeivarjovi, Ebrahim

    2017-09-01

    In this study starch/PVA/ZnO nanocomposite films with antibacterial activity were prepared and modified using gamma irradiation for packaging applications. ZnO nanoparticles (NPs) were synthesized from Zn(OH)2 using hydrothermal process and characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The prepared ZnO NPs were incorporated into blend films of starch and poly (vinyl alcohol) (PVA) with different concentrations from 0.1 to 1 wt% using solution casting method. The results of SEM confirmed good dispersion of ZnO NPs into the films while FTIR spectroscopy showed interactions between ZnO particles and starch/PVA blend. The nanocomposite films were irradiated at the dose range of 1-5 kGy. It was found that gamma irradiation induces a significant reduction in water absorptions of the films at the dose of 3 kGy. Different trends were observed for the tensile and elongation properties of the irradiated films. Based on the results, the bacterial growth on the films was effectively inhibited when the dosage of ZnO NPs was only 0.5 wt%.

  1. Nanostructured ZnO thin films prepared by sol-gel spin-coating

    NASA Astrophysics Data System (ADS)

    Heredia, E.; Bojorge, C.; Casanova, J.; Cánepa, H.; Craievich, A.; Kellermann, G.

    2014-10-01

    ZnO thin films deposited on silica flat plates were prepared by spin-coating and studied by applying several techniques for structural characterization. The films were prepared by depositing different numbers of layers, each deposition being followed by a thermal treatment at 200 °C to dry and consolidate the successive layers. After depositing all layers, a final thermal treatment at 450 °C during 3 h was also applied in order to eliminate organic components and to promote the crystallization of the thin films. The total thickness of the multilayered films - ranging from 40 nm up to 150 nm - was determined by AFM and FESEM. The analysis by GIXD showed that the thin films are composed of ZnO crystallites with an average diameter of 25 nm circa. XR results demonstrated that the thin films also exhibit a large volume fraction of nanoporosity, typically 30-40 vol.% in thin films having thicknesses larger than ∼70 nm. GISAXS measurements showed that the experimental scattering intensity is well described by a structural model composed of nanopores with shape of oblate spheroids, height/diameter aspect ratio within the 0.8-0.9 range and average diameter along the sample surface plane in the 5-7 nm range.

  2. Preparation and characterization of nanodiamond cores coated with a thin Ni-Zn-P alloy film

    SciTech Connect

    Wang Rui; Ye Weichun; Ma Chuanli; Wang Chunming

    2008-02-15

    Nanodiamond cores coated with a thin Ni-Zn-P alloy film were prepared by an electroless deposition method under the conditions of tin chloride sensitization and palladium chloride activation. The prepared materials were analyzed by Fourier transform infrared (FTIR) spectrometry and X-ray diffraction (XRD). The nanostructure of the materials was then characterized by transmission electron microscopy (TEM). The alloy film composition was characterized by Energy Dispersive X-ray (EDX) analysis. The results indicated the approximate composition 49.84%Ni-37.29%Zn-12.88%P was obtained.

  3. [Study on the Properties of the Pc-Si Films Prepared by Magnetron Co-Sputtering at Low Temperature].

    PubMed

    Duan, Liang-fei; Yang, Wen; Zhang, Li-yuan; Li, Xue-ming; Chen, Xiao-bo; Yang, Pei-zhi

    2016-03-01

    The polycrystalline silicon thin films play an important role in the field of electronics. In the paper, α-SiAl composite membranes on glass substrates was prepared by magnetron co-sputtering. The contents of Al radicals encapsulated-in the α-Si film can be adjusted by changing the Al to Si sputtering power ratios. The as-prepared α-Si films were converted into polycrystalline films by using a rapid thermal annealing (RTP) at low temperature of 350 degrees C for 10 minutes in N2 atmosphere. An X-ray diffractometer, and Raman scattering and UV-Visible-NIR Spectrometers were used to characterize the properties of the Pc-Si films. The influences of Al content on the properties of the Pc-Si films were studied. The results showed that the polycrystalline silicon films were obtained from α-SiAl composite films which were prepared by magnetron co-sputtering at a low temperature following by a rapid thermal annealing. The grain size and the degree of crystallization of the Pc-Si films increased with the increase of Al content, while the optical band gap was reduced. The nc-Si films were prepared when the Al to Si sputtering power ratio was 0.1. And a higher Crystallization rate (≥ 85%) of polycrystalline silicon films were obtained when the ratio was 0.3. The band gaps of the polycrystalline silicon films can be controlled by changing the aluminum content in the films.

  4. Using the Photolysis of Chemically Modified Gel Films Preparing ITO Fine Patterned Thin Films

    NASA Astrophysics Data System (ADS)

    Li, Ying; Zhao, Gaoyang; Zhang, Weihua; Chen, Yuanqing

    2006-06-01

    A novel technique for the fabrication of tin-doped indium oxide (ITO) fine patterning in sol-gel technology is presented in this paper. The fabricated ITO fine patterning could be obtained through a process which combines film fabrication with film etching. ITO films have good comprehensive property of visible transmittance and electrical conductivity, consequently they have been extensively used as coating electrodes. Indium nitrate (In(NO3)3.4.5H2O) and stannic chloride (SnCl4.5H2O) were used as starting materials which were modified with benzytone (BzAcH). The chelate complexes containing indium ions were produced during the process which of forming photosensitive ITO/BzAcH gel films through sol-gel technique. It was found that the gel films are sensitive to both the ultraviolet (UV) light irradiation and their solubility on solvents as well. For example, ethanol was reduced remarkably while the UV absorption peak disappeared with the dissociation of the chelate complexes correspondingly by means of UV-vis and IR spectrophotometers. Utilizing these characteristics, a fine pattern was obtained by irradiation of UV light on the ITO/BzAcH gel films through a pattern mask. of the fine patterned ITO films were heat treated at 500 °C for 15 min, the optical, electrical properties and the surface element components were examined by X-ray photoelectron spectroscopy (XPS) spectra in this work.

  5. CO responses of sensors based on cerium oxide thick films prepared from clustered spherical nanoparticles.

    PubMed

    Izu, Noriya; Matsubara, Ichiro; Itoh, Toshio; Akamatsu, Takafumi; Shin, Woosuck

    2013-03-08

    Various types of CO sensors based on cerium oxide (ceria) have been reported recently. It has also been reported that the response speed of CO sensors fabricated from porous ceria thick films comprising nanoparticles is extremely high. However, the response value of such sensors is not suitably high. In this study, we investigated methods of improving the response values of CO sensors based on ceria and prepared gas sensors from core-shell ceria polymer hybrid nanoparticles. These hybrid nanoparticles have been reported to have a unique structure: The core consists of a cluster of ceria crystallites several nanometers in size. We compared the characteristics of the sensors based on thick films prepared from core-shell nanoparticles with those of sensors based on thick films prepared from conventionally used precipitated nanoparticles. The sensors prepared from the core-shell nanoparticles exhibited a resistance that was ten times greater than that of the sensors prepared from the precipitated nanoparticles. The response values of the gas sensors based on the core-shell nanoparticles also was higher than that of the sensors based on the precipitated nanoparticles. Finally, improvements in sensor response were also noticed after the addition of Au nanoparticles to the thick films used to fabricate the two types of sensors.

  6. CO Responses of Sensors Based on Cerium Oxide Thick Films Prepared from Clustered Spherical Nanoparticles

    PubMed Central

    Izu, Noriya; Matsubara, Ichiro; Itoh, Toshio; Akamatsu, Takafumi; Shin, Woosuck

    2013-01-01

    Various types of CO sensors based on cerium oxide (ceria) have been reported recently. It has also been reported that the response speed of CO sensors fabricated from porous ceria thick films comprising nanoparticles is extremely high. However, the response value of such sensors is not suitably high. In this study, we investigated methods of improving the response values of CO sensors based on ceria and prepared gas sensors from core-shell ceria polymer hybrid nanoparticles. These hybrid nanoparticles have been reported to have a unique structure: The core consists of a cluster of ceria crystallites several nanometers in size. We compared the characteristics of the sensors based on thick films prepared from core-shell nanoparticles with those of sensors based on thick films prepared from conventionally used precipitated nanoparticles. The sensors prepared from the core-shell nanoparticles exhibited a resistance that was ten times greater than that of the sensors prepared from the precipitated nanoparticles. The response values of the gas sensors based on the core-shell nanoparticles also was higher than that of the sensors based on the precipitated nanoparticles. Finally, improvements in sensor response were also noticed after the addition of Au nanoparticles to the thick films used to fabricate the two types of sensors. PMID:23529123

  7. Preparation of thin ceramic films via an aqueous solution route

    DOEpatents

    Pederson, Larry R.; Chick, Lawrence A.; Exarhos, Gregory J.

    1989-01-01

    A new chemical method of forming thin ceramic films has been developed. An aqueous solution of metal nitrates or other soluble metal salts and a low molecular weight amino acid is coated onto a substrate and pyrolyzed. The amino acid serves to prevent precipitation of individual solution components, forming a very viscous, glass-like material as excess water is evaporated. Using metal nitrates and glycine, the method has been demonstrated for zirconia with various levels of yttria stabilization, for lanthanum-strontium chromites, and for yttrium-barium-copper oxide superconductors on various substrates.

  8. Structural and optoelectronic characterization of TiO2 films prepared using the sol gel technique

    NASA Astrophysics Data System (ADS)

    Jiménez González, A. E.; Gelover Santiago, S.

    2007-07-01

    TiO2 is a versatile material that makes for fascinating study in any of its several physical forms: monocrystal, polycrystal, powder or thin film. Its enhanced photosensitivity to UV radiation and excellent chemical stability in acidic and aqueous media point to its excellent potential for use in a variety of applications, such as solar cells, electronic devices, chemical sensors and photocatalysts. Of late, thin films of TiO2 have permitted the study of physical and chemical properties that are almost impossible to examine in powders. Using the sol-gel technique, it was possible to prepare TiO2 films, and to specifically modify their characteristic properties by means of annealing treatments. Optical measurements carried out on sol-gel derived films produced results similar to those found in films prepared using the sputtering technique. The use of TiO2 films facilitates the study of the behaviour of crystalline structure, grain size, photoresponse, electrical conductivity in both darkness and light and energy band gap (Eg) as a function of treatment temperature. For the first time, it has been demonstrated that the photoconductivity of TiO2 becomes apparent at a treatment temperature of 350 °C, which means that below this temperature the material is not photosensitive. The photosensitivity (S) of TiO2 films prepared by the sol-gel technique reaches values between 100 and 104, surpassing by more than two orders of magnitude the photosensitivity of TiO2 in powder form. In addition, it was possible to study the surface crystalline structure, where TEM studies clearly revealed both the polycrystalline order and the atomic arrangements of the TiO2 films. Our findings will afford us an opportunity to better study the nature of TiO2 and to enhance its performance with respect to the above-mentioned applications.

  9. Electrochromic properties of nickel oxide thin films prepared by the sol-gel method

    SciTech Connect

    Miki, Takeshi; Yoshimura, Kazuki; Tai, Yutaka; Tazawa, Masato; Jin, P.; Tanemura, Sakae

    1995-12-31

    Recently electrochromic (EC) device has been attractive as a smart glazing to control heating, cooling and lighting loads of buildings and housing. Among various electrochromic materials, nickel oxide is one of the typical anode type materials. Here, the electrochromic nickel oxide films were prepared onto transparent conducting film on glass substrate by the sol-gel method using an ethylene glycol solution of nickel nitrate hexahydrate. The films produced by the dip-coating method and calcined at 250, 300 and 350 C. The formed films were characterized by their electrochromic behavior in cyclic voltammetry. The formed films showed electrochromic behavior in 1M KOH aqueous solution as electrolytic solution. The cyclic voltammograms were recorded up to 100 cycles for each film. The anodic peak of the coloration reaction appeared at approximately +400 mV, while the cathodic peak of the bleaching reaction occurred at about +200 mV vs. Ag/AgCl. Both the anodic peak and the cathodic peak increased with an increase of the cyclic numbers in voltammograms, whereas these peaks at 100 cycles decreased with an increase of the calcination temperature of nickel oxide films. The calcination gave great influence on the other electrochromic behaviors of nickel oxide films.

  10. Characterization of lead zirconate titanate--lanthanum ruthenate thin film structures prepared by chemical solution deposition.

    PubMed

    Bencan, Andreja; Malic, Barbara; Drazic, Goran; Vukadinović, Miso; Kosec, Marija

    2007-01-01

    In this work, the results of compositional and microstructural analysis of lead zirconate titanate--lanthanum ruthenate thin film structures prepared by chemical solution deposition are discussed. The cross-section transmission electron microscope (TEM) micrographs of the La-Ru-O film deposited on a SiO2/Si substrate and annealed at 700 degrees C revealed RuO2 crystals embedded in a glassy silicate matrix. When the La-Ru-O film was deposited on a Pt/TiO2/SiO2/Si substrate, RuO2 and La4Ru6O19 crystallized after annealing at 700 degrees C. After firing at 550 degrees C randomly oriented lead zirconate titanate (PZT) thin films crystallized on the La-Ru-O/SiO2/Si substrate, while on La-Ru-O/Pt/TiO2/SiO2/Si substrates PZT thin films with (111) preferred orientation were obtained. No diffusion of the Ru atoms in the PZT film was found. Ferroelectric response of PZT thin films on these substrates is shown in comparison with the PZT film deposited directly on the Pt/TiO2/SiO2/Si substrate without a La-Ru-O layer.

  11. Photoactive, porous honeycomb films prepared from Rose Bengal-grafted polystyrene.

    PubMed

    Pessoni, Laurence; Lacombe, Sylvie; Billon, Laurent; Brown, Ross; Save, Maud

    2013-08-13

    Honeycomb-structured porous polymer films based on photosensitizer-grafted polystyrene are prepared through the breath figure process. Rose Bengal (RB) photosensitizer is first attached to a well-defined poly(styrene-stat-4-vinylbenzyl chloride) statistical copolymer, synthesized by nitroxide-mediated radical polymerization. The RB grafted poly(styrene-stat-4-vinylbenzyl chloride) (ca. 20,000 g mol(-1) molar mass, 1.2 dispersity) leads to porous polymer films, with a hexagonal pore pattern, while a simple mixture of poly(styrene-stat-4-vinylbenzyl chloride) and the insoluble RB photosensitizer produced unstructured, nonporous films. The RB-grafted honeycomb films, compared with the corresponding nonporous flat films, are more efficient for oxidation of organic molecules via singlet oxygen production at a liquid/solid interface. The oxidations of 1,5-dihydroxynaphthalene to juglone and α-terpinene to ascaridole are followed in ethanol in the presence of both types of films. Oxidation of the organic molecules is a factor 5 greater with honeycomb compared to the nonporous films. This gain is ascribed to two factors: the specific location of the polar photosensitizer at the film interface and the greater exchange surface, as revealed by fluorescence and scanning electron microscopies.

  12. Preparation of sensitive and recyclable porous Ag/TiO2 composite films for SERS detection

    NASA Astrophysics Data System (ADS)

    Zhang, Zhengyi; Yu, Jiajie; Yang, Jingying; Lv, Xiang; Wang, Tianhe

    2015-12-01

    Porous Ag/TiO2 composite films were prepared by spin coating of titania on normal glass slides and subsequent photochemical deposition of silver nanoparticles (AgNPs). The films were characterized by XRD and FESEM to reveal micro structural and morphological differences between films obtained under varied conditions. The SERS properties of these films were investigated using aqueous crystal violet (CV) as probe molecules. The results indicate that the content of polyethylene glycol (PEG) and photo-reduction time had significant influences on both the microstructure and SERS performance of Ag/TiO2 films. The highest SERS sensitivity that allowed as low as 10-10 M aqueous CV to be detected, was achieved with the PEG/(C4H9O)4Ti molar ratio being 0.08% and with 30 min of UV irradiation. With this film a linear relationship was established through experiment between SERS intensity and CV concentration from 10-10 to 10-5 M, which could be used as a calibration curve for CV concentration measurement. In addition, the film could be reused as a SERS substrate for up to four times without significantly losing SERS sensitivity if a simple regeneration was followed. It is visualized that the Ag/TiO2 film on glass has potentials for being developed into a practical SERS substrate with high sensitivity and good reusability.

  13. Preparation of (001)-oriented Pb(Zr,Ti)O3 thin films and their piezoelectric applications.

    PubMed

    Fujii, Eiji; Takayama, Ryoichi; Nomura, Kouji; Murata, Akiko; Hirasawa, Taku; Tomozawa, Atsushi; Fujii, Satoru; Kamada, Takeshi; Torii, Hideo

    2007-12-01

    Preparation of (001)-oriented Pb(Zr,Ti)O(3) (PZT) thin films and their applications to a sensor and actuators were investigated. These thin films, which have a composition close to the morphotropic phase boundary, were epitaxially grown on (100)MgO single-crystal substrates by RF magnetron sputtering. These (001)-oriented PZT thin films could be obtained on various kinds of substrates, such as glass and Si, by introducing (100)-oriented MgO buffer layers. In addition, the (001) oriented PZT thin films could be obtained on Si substrates without buffer layers by optimizing the sputtering conditions. All of these thin films showed excellent piezoelectric properties without the need for poling treatment. The PZT thin films on the MgO substrates had a high piezoelectric coefficient, d(31), of -100 pm/V, and an extremely low relative dielectric constant, epsilon(r), of 240. The PZT thin films on Si substrate had a very high d(31) of -150 pm/V and an epsilon(r) = 700. These PZT thin films were applied to an angular rate sensor with a tuning fork in a car navigation system, to a dual-stage actuator for positioning the magnetic head of a high-density hard disk drive, and to an actuator for an inkjet printer head for industrial on-demand printers.

  14. Preparation and characterization of mesoporous Nb2O5 films for sensing applications

    NASA Astrophysics Data System (ADS)

    Lazarova, K.; Georgieva, B.; Spasova, M.; Babeva, T.

    2014-12-01

    The possibility of combining sol-gel synthesis with molecular self-assembly and phase separation is explored to produce Nb2O5 films with tailored pore structures at the nanometer scale. Thin Nb2O5 film are fabricated by spin coating of a Nb sol prepared by sonocatalytic method using NbCl5 and ethanol mixed with structure directing agent Pluronic PE 6800 in different concentrations which acts as a supra molecular pore template. Post deposition treatment is applied for film consolidation and pore formation. Surface morphology and structure of the films are studied by Transmission Electron Microscopy and Selected Area Electron Diffraction. The optical properties (refractive index and extinction coefficient) along with the thickness of the films are determined from reflectance spectra of films deposited on silicon substrates. The overall porosity of the films and the amount of adsorbed acetone vapors are quantified by means of Bruggeman effective medium approximation using already determined optical constants. The sensing properties of the samples are studied by measuring reflectance spectra prior to and after exposure to acetone vapors with controlled concentrations. Furthermore, the potential of using the studied mesoporous Nb2O5 films for chemical sensing with optical read-out is demonstrated and discussed.

  15. Surface modification of silicon-containing fluorocarbon films prepared by plasma-enhanced chemical vapor deposition

    NASA Astrophysics Data System (ADS)

    Jin, Yoonyoung; Desta, Yohannes; Goettert, Jost; Lee, G. S.; Ajmera, P. K.

    2005-07-01

    Surface modification of silicon-containing fluorocarbon (SiCF) films achieved by wet chemical treatments and through x-ray irradiation is examined. The SiCF films were prepared by plasma-enhanced chemical vapor deposition, using gas precursors of tetrafluoromethane and disilane. As-deposited SiCF film composition was analyzed by x-ray photoelectron spectroscopy. Surface modification of SiCF films utilizing n-lithiodiaminoethane wet chemical treatment is discussed. Sessile water-drop contact angle changed from 95°+/-2° before treatment to 32°+/-2° after treatment, indicating a change in the film surface characteristics from hydrophobic to hydrophilic. For x-ray irradiation on the SiCF film with a dose of 27.4 kJ/cm3, the contact angle of the sessile water drop changed from 95°+/-2° before radiation to 39°+/-3° after x-ray exposure. The effect of x-ray exposure on chemical bond structure of SiCF films is studied using Fourier transform infrared measurements. Electroless Cu deposition was performed to test the applicability of the surface modified films. The x-ray irradiation method offers a unique advantage in making possible surface modification in a localized area of high-aspect-ratio microstructures. Fabrication of a Ti-membrane x-ray mask is introduced here for selective surface modification using x-ray irradiation.

  16. Preparation and characterization of chitosan-based nanocomposite films with antimicrobial activity.

    PubMed

    Rhim, Jong-Whan; Hong, Seok-In; Park, Hwan-Man; Ng, Perry K W

    2006-08-09

    Four different types of chitosan-based nanocomposite films were prepared using a solvent-casting method by incorporation with four types of nanoparticles, that is, an unmodified montmorillonite (Na-MMT), an organically modified montmorillonite (Cloisite 30B), a Nano-silver, and a Ag-zeolite (Ag-Ion). X-ray diffraction patterns of the nanocomposite films indicated that a certain degree of intercalation was formed in the nanocomposite films, with the highest intercalation in the Na-MMT-incorporated films followed by films with Cloisite 30B and Ag-Ion. Scanning electron micrographs showed that in all of the nanocomposite films, except the Nano-silver-incorporated one, nanoparticles were dispersed homogeneously throughout the chitosan polymer matrix. Consequently, mechanical and barrier properties of chitosan films were affected through intercalation of nanoparticles, that is, tensile strength increased by 7-16%, whereas water vapor permeability decreased by 25-30% depending on the nanoparticle material tested. In addition, chitosan-based nanocomposite films, especially silver-containing ones, showed a promising range of antimicrobial activity.

  17. Preparation and Characterization of Blended Films from Quaternized Hemicelluloses and Carboxymethyl Cellulose

    PubMed Central

    Qi, Xian-Ming; Liu, Shi-Yun; Chu, Fang-Bing; Pang, Shuai; Liang, Yan-Ru; Guan, Ying; Peng, Feng; Sun, Run-Cang

    2015-01-01

    Utilization of hemicelluloses from biomass energy is an important approach to explore renewable resources. A convenient, quick, and inexpensive method for the preparation of blended films from quaternized hemicelluloses (QH) and carboxymethyl cellulose (CMC) was introduced into this study. QH and CMC solution were first mixed to form homogeneous suspension, and then were dried under vacuum to fabricate the blended films. The FT-IR and XRD results indicated that the linkage between QH and CMC was due to the hydrogen bonding and electrostatic interaction. From the results of mechanical properties and water vapor permeability (WVP), the tensile strength of the blended films increased with the QH/CMC content ratio increasing in appropriate range, and the WVP of the blended films decreased. The maximum value of tensile strength of blend film achieved was 27.4 MPa. In addition, the transmittances of the blended films increased with the decreasing of QH/CMC content ratio. When the weight ratio (QH: CMC) was 1:1.5, the blend film showed the best light transmittance (45%). All the results suggested that the blended films could be used in areas of application in the coating and packaging fields from the good tensile strength, transmittance, and low WVP. PMID:28787804

  18. Bio-based barium alginate film: Preparation, flame retardancy and thermal degradation behavior.

    PubMed

    Liu, Yun; Zhang, Chuan-Jie; Zhao, Jin-Chao; Guo, Yi; Zhu, Ping; Wang, De-Yi

    2016-03-30

    A bio-based barium alginate film was prepared via a facile ionic exchange and casting approach. Its flammability, thermal degradation and pyrolysis behaviors, thermal degradation mechanism were studied systemically by limiting oxygen index (LOI), vertical burning (UL-94), microscale combustion calorimetry (MCC), thermogravimetric analysis (TGA) coupled with Fourier transform infrared analysis (FTIR) and pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS). It showed that barium alginate film had much higher LOI value (52.0%) than that of sodium alginate film (24.5%). Moreover, barium alginate film passed the UL-94 V-0 rating, while the sodium alginate film showed no classification. Importantly, peak of heat release rate (PHRR) of barium alginate film in MCC test was much lower than that of sodium alginate film, suggested that introduction of barium ion into alginate film significantly decreased release of combustible gases. TG-FTIR and Py-GC-MS results indicated that barium alginate produced much less flammable products than that of sodium alginate in whole thermal degradation procedure. Finally, a possible degradation mechanism of barium alginate had been proposed. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. A facile route to prepare cellulose-based films.

    PubMed

    Xu, Qin; Chen, Chen; Rosswurm, Katelyn; Yao, Tianming; Janaswamy, Srinivas

    2016-09-20

    Cellulose is the most abundant renewable and biodegradable material available in nature. Its insoluble character in water as well as common organic and inorganic liquids, however, curtails the wholesome utility. The continuous rise for biodegradable products based on cellulose coupled with its intrinsic ability to form a viable substitute for the petroleum-based materials necessitates the critical need for solubilizing the cellulose. Herein, we demonstrate the feasibility of ZnCl2 solutions, especially the 64-72% concentrations, to dissolve cellulose. FTIR results suggest that Zn(2+) ions promote Zn⋯O3H interactions, which in-turn weaken the intrinsic O3H⋯O5 hydrogen bonds that are responsible for strengthening the cellulose chains. Interestingly, Ca(2+) ions promote interactions among the Zn-cellulose chains leading to the formation of nano fibrils and yield gelling solutions. The tensile strength of the Ca(2+) added Zn-cellulose films increases by around 250% compared to the Zn-cellulose films. Overall, utilization of inorganic salt solutions to solubilize and crosslink cellulose is cost-effective, recyclable and certainly stands out tall among the other available systems. More importantly, the proposed protocol is simple and is a "green" process, and thus its large-scale adaptability is quite feasible. We strongly believe that the outcome opens up a new window of opportunities for cellulose in the biomedical, pharmaceutical, food and non-food applications. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Optical and electron paramagnetic resonance studies of hydrogenated amorphous carbon (a-C:H) thin films formed by direct ion beam deposition method

    NASA Astrophysics Data System (ADS)

    Silinskas, M.; Grigonis, A.; Dikcius, G.; Manikowski, H.

    2001-04-01

    The diamond-like carbon films, deposited by direct ion beam deposition method using mixture of C6H14 and H2 with and without silicon presence, have been investigated by Raman spectroscopy, X-ray photoelectron spectroscopy, ellipsometry, IR-visible-UV transmission, and electron paramagnetic resonance techniques. The D and G line widths and peak positions, integrated intensity ratio (ID/IG) in Raman spectra indicate these films being amorphous, mixture of sp2 and sp3 bonds. It has been found that a-C:H films formed while increasing substrate temperature and deposition ion energy tend to be graphite-like. Increasing of hydrogen content in gas mixture made these films more polymer-like with low content of dangling bonds. Traces of silicon increase sp3/sp2 ratio. The DLC films on silicon are able to greatly reduce IR reflection.

  1. Preparation of Macroporous Epitaxial Quartz Films on Silicon by Chemical Solution Deposition.

    PubMed

    Carretero-Genevrier, Adrián; Gich, Martí

    2015-12-21

    This work describes the detailed protocol for preparing piezoelectric macroporous epitaxial quartz films on silicon(100) substrates. This is a three-step process based on the preparation of a sol in a one-pot synthesis which is followed by the deposition of a gel film on Si(100) substrates by evaporation induced self-assembly using the dip-coating technique and ends with a thermal treatment of the material to induce the gel crystallization and the growth of the quartz film. The formation of a silica gel is based on the reaction of a tetraethyl orthosilicate and water, catalyzed by HCl, in ethanol. However, the solution contains two additional components that are essential for preparing mesoporous epitaxial quartz films from these silica gels dip-coated on Si. Alkaline earth ions, like Sr(2+) act as glass melting agents that facilitate the crystallization of silica and in combination with cetyl trimethylammonium bromide (CTAB) amphiphilic template form a phase separation responsible of the macroporosity of the films. The good matching between the quartz and silicon cell parameters is also essential in the stabilization of quartz over other SiO2 polymorphs and is at the origin of the epitaxial growth.

  2. Fabrication of Cu2O nanocrystalline thin films photosensor prepared by RF sputtering technique

    NASA Astrophysics Data System (ADS)

    Selman, Abbas M.; Mahdi, M. A.; Hassan, Z.

    2017-10-01

    Cuprous oxide (Cu2O) nanocrystalline thin films were prepared on two types of substrates known as crystalline silicon and amorphous glass, by radio frequency reactive magnetron sputtering method. Scanning electron microscopy images confirmed that Cu2O particles covered the entire surface of both substrates with smoothing distribution. The root mean square surface roughness for the prepared Cu2O thin films on glass and Si (111) substrates is 4.16, and 3.36 nm, respectively. Meanwhile, X-ray diffraction results demonstrated that the two phases of Cu2O and CuO were produced on Si (111) and glass substrates. The optical bandgap of Cu2O thin films synthesised on glass substrate is 2.42 eV. Furthermore, the prepared Cu2O nanocrystalline thin films have showed low reflectance value in the visible spectrum. Metal-Semiconductor-Metal photodetector based Cu2O nanocrystalline thin films deposited onto Si (111) was fabricated using aluminium and platinum, with the current-voltage and photoresponse characteristic investigated under various applied bias voltages. The fabricated Metal-Semiconductor-Metal (M-S-M) photodetector had shown 126% sensitivity in the presence of 10 mW/cm2 of 490 nm light with 1.0 V bias, displaying 90 and 100 ms response and recovery times, respectively. These findings have demonstrated the suitability of M-S-M Cu2O photodetector as an affordable photosensor in the future.

  3. Controlling morphology, mesoporosity, crystallinity, and photocatalytic activity of ordered mesoporous TiO{sub 2} films prepared at low temperature

    SciTech Connect

    Elgh, Björn; Yuan, Ning; Palmqvist, Anders E. C.; Cho, Hae Sung; Terasaki, Osamu; Magerl, David; Philipp, Martine; Müller-Buschbaum, Peter; Roth, Stephan V.; Yoon, Kyung Byung

    2014-11-01

    Partly ordered mesoporous titania films with anatase crystallites incorporated into the pore walls were prepared at low temperature by spin-coating a microemulsion-based reaction solution. The effect of relative humidity employed during aging of the prepared films was studied using SEM, TEM, and grazing incidence small angle X-ray scattering to evaluate the mesoscopic order, porosity, and crystallinity of the films. The study shows unambiguously that crystal growth occurs mainly during storage of the films and proceeds at room temperature largely depending on relative humidity. Porosity, pore size, mesoscopic order, crystallinity, and photocatalytic activity of the films increased with relative humidity up to an optimum around 75%.

  4. Preparation and characterization of epitaxially grown unsupported yttria-stabilized zirconia (YSZ) thin films

    NASA Astrophysics Data System (ADS)

    Götsch, Thomas; Mayr, Lukas; Stöger-Pollach, Michael; Klötzer, Bernhard; Penner, Simon

    2015-03-01

    Epitaxially grown, chemically homogeneous yttria-stabilized zirconia thin films ("YSZ", 8 mol% Y2O3) are prepared by direct-current sputtering onto a single-crystalline NaCl(0 0 1) template at substrate temperatures ≥493 K, resulting in unsupported YSZ films after floating off NaCl in water. A combined methodological approach by dedicated (surface science) analytical characterization tools (transmission electron microscopy and diffraction, atomic force microscopy, angle-resolved X-ray photoelectron spectroscopy) reveals that the film grows mainly in a [0 0 1] zone axis and no Y-enrichment in surface or bulk regions takes place. In fact, the Y-content of the sputter target is preserved in the thin films. Analysis of the plasmon region in EEL spectra indicates a defective nature of the as-deposited films, which can be suppressed by post-deposition oxidation at 1073 K. This, however, induces considerable sintering, as deduced from surface morphology measurements by AFM. In due course, the so-prepared unsupported YSZ films might act as well-defined model systems also for technological applications.

  5. Freestanding films of crosslinked gold nanoparticles prepared via layer-by-layer spin-coating.

    PubMed

    Schlicke, Hendrik; Schröder, Jan H; Trebbin, Martin; Petrov, Alexey; Ijeh, Michael; Weller, Horst; Vossmeyer, Tobias

    2011-07-29

    A new, extremely efficient method for the fabrication of films comprised of gold nanoparticles (GNPs) crosslinked by organic dithiols is presented in this paper. The method is based on layer-by-layer spin-coating of both components, GNPs and crosslinker, and enables the deposition of films several tens of nanometers in thickness within a few minutes. X-ray diffraction and conductance measurements reveal the proper adjustment concentration of the crosslinker solution of the critical is in order to prevent the destabilization and coalescence of particles. UV/vis spectroscopy, atomic force microscopy, and conductivity measurements indicate that films prepared via layer-by-layer spin-coating are of comparable quality to coatings prepared via laborious layer-by-layer self-assembly using immersion baths. Because spin-coated films are not bound chemically to the substrate, they can be lifted-off by alkaline underetching and transferred onto 3d-electrodes to produce electrically addressable, freely suspended films. Comparative measurements of the sheet resistances indicate that the transfer process does not compromise the film quality.

  6. Freestanding films of crosslinked gold nanoparticles prepared via layer-by-layer spin-coating

    NASA Astrophysics Data System (ADS)

    Schlicke, Hendrik; Schröder, Jan H.; Trebbin, Martin; Petrov, Alexey; Ijeh, Michael; Weller, Horst; Vossmeyer, Tobias

    2011-07-01

    A new, extremely efficient method for the fabrication of films comprised of gold nanoparticles (GNPs) crosslinked by organic dithiols is presented in this paper. The method is based on layer-by-layer spin-coating of both components, GNPs and crosslinker, and enables the deposition of films several tens of nanometers in thickness within a few minutes. X-ray diffraction and conductance measurements reveal the proper adjustment concentration of the crosslinker solution of the critical is in order to prevent the destabilization and coalescence of particles. UV/vis spectroscopy, atomic force microscopy, and conductivity measurements indicate that films prepared via layer-by-layer spin-coating are of comparable quality to coatings prepared via laborious layer-by-layer self-assembly using immersion baths. Because spin-coated films are not bound chemically to the substrate, they can be lifted-off by alkaline underetching and transferred onto 3d-electrodes to produce electrically addressable, freely suspended films. Comparative measurements of the sheet resistances indicate that the transfer process does not compromise the film quality.

  7. Preparation of Nanocellulose Reinforced Chitosan Films, Cross-Linked by Adipic Acid.

    PubMed

    Falamarzpour, Pouria; Behzad, Tayebeh; Zamani, Akram

    2017-02-13

    Adipic acid, an abundant and nontoxic compound, was used to dissolve and cross-link chitosan. After the preparation of chitosan films through casting technique, the in situ amidation reaction was performed at 80-100 °C as verified by Fourier transform infrared (FT-IR). The reaction was accompanied by the release of water which was employed to investigate the reaction kinetics. Accordingly, the reaction rate followed the first-order model and Arrhenius equation, and the activation energy was calculated to be 18 kJ/mol. Furthermore, the mechanical properties of the chitosan films were comprehensively studied. First, optimal curing conditions (84 °C, 93 min) were introduced through a central composite design. In order to evaluate the effects of adipic acid, the mechanical properties of physically cross-linked (uncured), chemically cross-linked (cured), and uncross-linked (prepared by acetic acid) films were compared. The use of adipic acid improved the tensile strength of uncured and chemically cross-linked films more than 60% and 113%, respectively. Finally, the effect of cellulose nanofibrils (CNFs) on the mechanical performance of cured films, in the presence of glycerol as a plasticizer, was investigated. The plasticized chitosan films reinforced by 5 wt % CNFs showed superior properties as a promising material for the development of chitosan-based biomaterials.

  8. Electrical and optical properties of Al doped Zno film prepared by spray pyrolysis technique

    NASA Astrophysics Data System (ADS)

    Shrestha, Shankar Prasad; Basnet, Pradeep

    2008-04-01

    Transparent conducting thin films of zinc oxides and aluminum doped zinc oxide (AZO) were prepared by the spray pyrolysis technique using an aqueous solution of dehydrate zinc acetate (CH 3COOH. 2H IIO, pure- Merck A. R. grade) and hex hydrate aluminum chloride (AlCl 3 .6H IIO) on the micro glass slides. The prepared thin films are found to be highly adherent to the substrate and possess uniform conduction. The optical and electrical properties of the film were investigated in terms of different Al concentration in the starting solution and different substrate temperature. Four probe method in Van der pauw configuration was used for electrical resistivity measurements. The resistivity of Al doped film is observed to vary with doping concentration. The lowest resistivity is observed in the film doping with 2 at % [Al/Zn]. The Hall coefficient measurements show that both ZnO and AZO show the n-type conduction. The carrier concentration was observed to be highest at 2 at% of Al doping. The optical measurements of all the samples with aluminum concentrations was found to be >85 % showing the film to be highly transparent in nature. With increase in Al concentration, the optical band gap was observed increase from 3.27 eV to 3.41 eV.

  9. Preparation and characterization of bio-nanocomposite films of agar and silver nanoparticles: laser ablation method.

    PubMed

    Rhim, Jong-Whan; Wang, Long-Feng; Lee, Yonghoon; Hong, Seok-In

    2014-03-15

    Silver nanoparticles (AgNPs) were prepared by a laser ablation method and composite films with the AgNPs and agar were prepared by solvent casting method. UV-vis absorbance test and transmission electron microscopy (TEM) analysis results revealed that non-agglomerated spherical AgNPs were formed by the laser ablation method. The surface color of the resulting agar/AgNPs films exhibited the characteristic plasmonic effect of the AgNPs with the maximum absorption peaks of 400-407 nm. X-ray diffraction (XRD) test results also exhibited characteristic AgNPs crystals with diffraction peaks observed at 2θ values of 38.39°, 44.49°, and 64.45°, which were corresponding to (111), (200), and (220) crystallographic planes of face-centered cubic (fcc) silver crystals, respectively. Thermogravimetric analysis (TGA) results showed that thermal stability of the agar/AgNPs composite films was increased by the inclusion of metallic silver. Water vapor barrier properties and surface hydrophobicity of the agar/AgNPs films increased slightly with the increase in AgNPs content but they were not statistically significant (p>0.05), while mechanical strength and stiffness of the composite films decreased slightly (p<0.05). The agar/AgNPs films exhibited distinctive antimicrobial activity against both Gram-positive (Listeria monocytogenes) and Gram-negative (Escherichia coli O157:H7) bacterial pathogens. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Characterization of bionanocomposite films prepared with agar and paper-mulberry pulp nanocellulose.

    PubMed

    Reddy, Jeevan Prasad; Rhim, Jong-Whan

    2014-09-22

    Crystallized nanocellulose (CNC) was separated from paper-mulberry (Broussonetia kazinoki Siebold) bast pulp by sulfuric acid hydrolysis method and they were blended with agar to prepare bionanocomposite films. The effect of CNC content (1, 3, 5 and 10 wt% based on agar) on the mechanical, water vapor permeability (WVP), and thermal properties of the nanocomposites were studied. Changes of the cellulose fibers in structure, morphology, crystallinity, and thermal properties of the films were evaluated using FT-IR, TEM, SEM, XRD, and TGA analysis methods. The CNC was composed of fibrous and spherical or elliptic granules of nano-cellulose with sizes of 50-60 nm. Properties of agar film such as mechanical and water vapor barrier properties were improved significantly (p<0.05) by blending with the CNC. The tensile modulus and tensile strength of agar film increased by 40% and 25%, respectively, in the composite film with 5 wt% of CNC, and the WVP of agar film decreased by 25% after formation of nanocomposite with 3 wt% of CNC. The CNC obtained from the paper-mulberry bast pulp can be used as a reinforcing agent for the preparation of bio-nanocomposites, and they have a high potential for the development of completely biodegradable food packaging materials. Copyright © 2014 Elsevier Ltd. All rights reserved.

  11. Preparation of bioactive titania films on titanium metal via anodic oxidation.

    PubMed

    Cui, X; Kim, H-M; Kawashita, M; Wang, L; Xiong, T; Kokubo, T; Nakamura, T

    2009-01-01

    To research the crystal structure and surface morphology of anodic films on titanium metal in different electrolytes under various electrochemical conditions and investigate the effect of the crystal structure of the oxide films on apatite-forming ability in simulated body fluid (SBF). Titanium oxide films were prepared using an anodic oxidation method on the surface of titanium metal in four different electrolytes: sulfuric acid, acetic acid, phosphoric acid and sodium sulfate solutions with different voltages for 1 min at room temperature. Anodic films that consisted of rutile and/or anatase phases with porous structures were formed on titanium metal after anodizing in H(2)SO(4) and Na(2)SO(4) electrolytes, while amorphous titania films were produced after anodizing in CH(3)COOH and H(3)PO(4) electrolytes. Titanium metal with the anatase and/or rutile crystal structure films showed excellent apatite-forming ability and produced a compact apatite layer covering all the surface of titanium after soaking in SBF for 7d, but titanium metal with amorphous titania layers was not able to induce apatite formation. The resultant apatite layer formed on titanium metal in SBF could enhance the bonding strength between living tissue and the implant. Anodic oxidation is believed to be an effective method for preparing bioactive titanium metal as an artificial bone substitute even under load-bearing conditions.

  12. Network structures and thermal properties of polyurethane films prepared from liquefied wood.

    PubMed

    Kurimoto, Y; Takeda, M; Doi, S; Tamura, Y; Ono, H

    2001-03-01

    Polyurethane (PU) films were prepared by solution-casting after co-polymerization of liquefied woods (LWs) and polymeric methylene diphenylene diisocyanate (PMDI). The resulting PU films had various [NCO]/[OH] ratios ranging from 0.6 to 1.4 and contained 5.0-16.8% dissolved woody components at the [NCO]/[OH] ratio of 1.0. The crosslink densities of the films with [NCO]/[OH] ratios of 0.6-1.4 increased remarkably with increasing [NCO]/[OH] ratio. Similarly, there were large increases in glass transition temperatures (Tg). These characteristics could be attributed to effective incorporation of PMDI into the LW. The crosslink densities and Tg of the PU films prepared at the [NCO]/[OH] ratio of 1.0 increased because the amounts of dissolved woody components in the films increased. It is concluded that the dissolved woody components acted as crosslinking points in PU network formations. The thermal degradation of the PU films at an [NCO]/[OH] ratio of more than 0.8 or with more than 10.6% dissolved wood started above 262 degrees C under an N2 atmosphere. The thermostability was lost at low crosslink density or with large amount of co-polymerized glycerol structures in the PU networks.

  13. Bioactive TiO2 fiber films prepared by electrospinning method.

    PubMed

    Chen, S J; Yu, H Y; Yang, B C

    2013-01-01

    Electrospining method was used to prepare bioactive TiO(2) fibers films in this study. The acetic acid/ethanol/tetrabutyl titanate/polyvinylpyrrolidone (PVP) solvent system was used as precursor for the electrospining. The TiO(2) fiber structures (including its fiber diameter, morphology, and phase composition) could be controlled by changing feeding rate, PVP concentration and sinter temperature. The fiber films were subjected to simulated body fluid soaking experiments and MG63 cells culture experiments to study their bioactivity. According to the X-ray diffraction and MTT assay results, the fiber containing with anatase showed better apatite formation ability than that without anatase at the early stage, while cell proliferated on anatase-rutile TiO(2) fiber was better than that on other samples (p < 0.05).Some string beads in the fiber were beneficial for apatite formation, while the cell proliferated best on the fiber film without string beads (p < 0.05). The fiber with a diameter of 200 nm had the best apatite formation ability and osteoblast compatibility (p < 0.05). The results showed that the TiO(2) fiber film structure had great influence on its bioactivity. It indicated that the electronspining method is an effective way to prepare bioactive titania fiber films, and it is possible to control the structure of the films in the spinning process to optimize the bioactivity of TiO(2) fiber.

  14. Chemically prepared La2Se3 nanocubes thin film for supercapacitor application.

    PubMed

    Patil, S J; Lokhande, V C; Chodankar, N R; Lokhande, C D

    2016-05-01

    Lanthanum selenide (La2Se3) nanocubes thin film is prepared via successive ionic layer adsorption and reaction (SILAR) method and utilized for energy storage application. The prepared La2Se3 thin film is characterized by X-ray diffraction, field emission scanning electron microscopy and contact angle measurement techniques for structural, surface morphological and wettability studies, respectively. Energy dispersive X-ray microanalysis (EDAX) is performed in order to obtain the elemental composition of the thin film. The La2Se3 film electrode shows a maximum specific capacitance of 363 F g(-1) in a 0.8 M LiClO4/PC electrolyte at a scan rate of 5 mV s(-1) within 1.3 V/SCE potential range. The specific capacitive retention of 83 % of La2Se3 film electrode is obtained over 1000 cyclic voltammetry cycles. The predominant performance, such as high energy (80 Wh kg(-1)) and power density (2.5 kW kg(-1)), indicates that La2Se3 film electrode facilitates fast ion diffusion during redox processes.

  15. Preparation of Nanocellulose Reinforced Chitosan Films, Cross-Linked by Adipic Acid

    PubMed Central

    Falamarzpour, Pouria; Behzad, Tayebeh; Zamani, Akram

    2017-01-01

    Adipic acid, an abundant and nontoxic compound, was used to dissolve and cross-link chitosan. After the preparation of chitosan films through casting technique, the in situ amidation reaction was performed at 80–100 °C as verified by Fourier transform infrared (FT-IR). The reaction was accompanied by the release of water which was employed to investigate the reaction kinetics. Accordingly, the reaction rate followed the first-order model and Arrhenius equation, and the activation energy was calculated to be 18 kJ/mol. Furthermore, the mechanical properties of the chitosan films were comprehensively studied. First, optimal curing conditions (84 °C, 93 min) were introduced through a central composite design. In order to evaluate the effects of adipic acid, the mechanical properties of physically cross-linked (uncured), chemically cross-linked (cured), and uncross-linked (prepared by acetic acid) films were compared. The use of adipic acid improved the tensile strength of uncured and chemically cross-linked films more than 60% and 113%, respectively. Finally, the effect of cellulose nanofibrils (CNFs) on the mechanical performance of cured films, in the presence of glycerol as a plasticizer, was investigated. The plasticized chitosan films reinforced by 5 wt % CNFs showed superior properties as a promising material for the development of chitosan-based biomaterials. PMID:28208822

  16. Preparation of amorphous and crystalline Ag/TiO2 nanocomposite thin films

    NASA Astrophysics Data System (ADS)

    Viana, M. M.; Mohallem, N. D. S.; Miquita, D. R.; Balzuweit, K.; Silva-Pinto, E.

    2013-01-01

    Ag/TiO2 thin films have been prepared on glass substrates by the dip-coating technique and sol-gel process using a precursor solution containing titanium alkoxide and silver nitrate in an Ag/Ti atomic ratio of 1:6 and 1:100. These films were annealed at 100 °C and 400 °C and cooled rapidly to obtain silver nanoparticles dispersed in an amorphous TiO2 matrix, confirmed by X-ray diffraction (XRD) analyses. Ag/TiO2 nanocrystalline films were also prepared using slow cooling. Silver nanoparticles coalesced and migrated to the thin film surfaces with increasing annealing temperature as observed by high-resolution transmission electron microscopy (HRTEM), scanning electron microscopy (SEM) and scanning probe microscopy (SPM). A transmission electron microscope (TEM) was used to induce phase transition in the amorphous matrix into anatase and rutile crystalline phases using a 200 kV electron beam. The variation of the Ag/Ti atomic ratio changed the plasmon resonance absorption and band gap values of the Ag/TiO2 films due to the change in the Ag nanoparticle sizes formed on the surface of films, as verified by UV-vis absorption spectroscopy and spectroscopic ellipsometry.

  17. Multilayered Zr-C/a-C film on stainless steel 316L as bipolar plates for proton exchange membrane fuel cells

    NASA Astrophysics Data System (ADS)

    Bi, Feifei; Peng, Linfa; Yi, Peiyun; Lai, Xinmin

    2016-05-01

    A multilayered zirconium-carbon/amorphous carbon (Zr-C/a-C) coating is synthesized by magnetron sputtering in order to improve the corrosion resistance and interfacial conductivity of stainless steel 316L (SS316L) as bipolar plates for proton exchange membrane fuel cells (PEMFCs). Zr-C/a-C film contains an outmost pure amorphous carbon layer and a sub zirconium containing carbon layer. Interfacial contact resistance (ICR) between carbon paper and coated SS316L decreases to 3.63 mΩ cm2 at 1.4 MPa. Potentiodynamic polarization results reveal that the corrosion potential of Zr-C/a-C coated sample is more positive than pure a-C coated sample and the current density is only 0.49 μA cm-2 at the cathode applied potential 0.6 V. Electrochemical impendence spectroscopy also indicates that multilayered Zr-C/a-C film coated SS316L has much higher charge transfer resistance than the bare sample. After potentiostatic polarization, ICR values are 3.92 mΩ cm2 and 3.82 mΩ cm2 in the simulated PEMFCs cathode and anode environment, respectively. Moreover, XPS analysis of the coated samples before and after potential holding tests shows little difference, which disclose the chemical stability of multilayered Zr-C/a-C film. Therefore, the multilayered Zr-C/a-C coating exhibits excellent performance in various aspects and is preferred for the application of stainless steel bipolar plates.

  18. Poly(vinyl alcohol) composite films with high percent elongation prepared from amylose-fatty ammonium salt inclusion complexes

    USDA-ARS?s Scientific Manuscript database

    Amylose inclusion complexes prepared from cationic fatty ammonium salts and jet-cooked high amylose starch were combined with poly(vinyl alcohol) (PVOH) to form glycerol-plasticized films. Their tensile properties were compared with similar films prepared previously with analogous anionic fatty acid...

  19. Preparation and characterization of solution cast films of PET, reorganized PET and their MWNT nanocomposites

    NASA Astrophysics Data System (ADS)

    Singh, Arvind R.; Deshpande, Vineeta D.

    2013-06-01

    The samples of polyethylene terephthalate (PET), reorganized PET (r-PET) and their nanocomposites with 0.05 wt % and 0.1 wt % multi walled carbon nanotubes (MWNT) were prepared by standard solution casting method using trifluoroacetic acid (TFA) as a solvent. Reorganization of PET was obtained by precipitation method using TFA as a solvent and acetone as an antisolvent. Structural and morphological properties of the films were investigated by Fourier Transform Infrared spectroscopy (FTIR), X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM). Differential Scanning Calorimetry (DSC) was used to study the thermal properties of the films. Bulk resistivity of the prepared samples was studied using LCR meter. The results show better dispersion of MWNT in r-PET than in PET. Better dispersion is attributed to the morphological changes in r-PET. The films obtained were conductive and transparent even after addition of MWNT signifying their use as a flexible solar substrate.

  20. Influence of oxygen on the quality of the PZT thin films prepared by IBS

    NASA Astrophysics Data System (ADS)

    Horodyska, Petra; Hlubucek, Jiri; Zidek, Karel; Vaclavik, Jan

    2016-11-01

    Pb(Zr,Ti)O3 (PZT) is a ferroelectric material interesting for its high dielectric constant and piezoelectric response. PZT thin films can be prepared by various methods, e.g. pulsed laser deposition, chemical vapor deposition, sol-gel and, most frequently, sputtering. Though the magnetron sputtering is used more frequently, PZT thin films can be prepared also by ion-beam sputtering (IBS). In this paper we study the deposition process of PZT thin films in our IBS system with a possibility of ion-beam assisted deposition (IBAD), which has the advantage that more energy can be added to the growing layer. We show how in our system the resulting layers, mainly their quality, the Pb content, which is important for the creation of the perovskite crystal structure, and the resulting crystal structure are influenced by the oxygen flux during the deposition for the samples grown on the silicon substrate with and without an intermediate Ti seeding layer.

  1. Effect of reaction temperature on carbon films prepared by a hydrothermal electrochemical method

    NASA Astrophysics Data System (ADS)

    Tao, Y.; Yi, D.; Zhu, B.

    2012-03-01

    Carbon films were synthesized under hydrothermal electrochemical conditions using sugar as the carbon source at temperature ranging from 170 °C to 180 °C. The reaction temperature affects the degree of sugar decomposition, the concentration of carbon ions, supersaturation and overpotential of the solution, thereby affecting the morphology, orientation, and crystallinity of the films. The graphitic content (sp2) increases with increasing the processing temperature and vice versa. The higher the synthesizing temperature the less the amount of amorphous carbon (sp3). The graphite in thin films prepared at 170 °C and 175 °C shows a (101) preferred orientation, whereas those prepared at 180 °C show a fairly random orientation. The mechanism of this synthesizing process seems to consist of three stages.

  2. Preparation of H2SO4 doped Polyaniline thin film solar cells by spin coating technique

    NASA Astrophysics Data System (ADS)

    Patel, Abhishek; Pataniya, Pratik; Patel, K. D.; Solanki, G. K.; Pathak, V. M.

    2017-05-01

    A water diluted H2SO4 solution was used to dissolve Polyaniline in order to obtain a solution for preparation of thin films by spin coating technique. The chemical bonding characteristics of the prepared films were investigated using Furrier transform infrared spectroscopy (FTIR) and the structural characterizations were accomplished by X-ray diffraction (XRD). UV-VIS absorption spectroscopy was used to determine the optical band gap of the deposited PANi films and the indirect optical band gap of PANi was estimated to be in the range of 1.3 to 1.8 eV from the Tauc's plot. Further, these films were deposited on the n-MoSe2 crystal in order to complete a solar cell structure. The polychromatic photo response of the prepared solar cells for different intensities was studied at room temperature and the efficiency and fill factor were found to be 1% and 0.26 respectively. The obtained Photo-conversion characteristics (I-V) were also used to determined series and shunt resistances of the prepared device. The series resistance was found to be around 33.3 kΩ which is quite high. This may be a reason for such a low efficiency of this cell.

  3. Properties of dry film lubricants prepared by spray application of aqueous starch-oil composites

    USDA-ARS?s Scientific Manuscript database

    Aqueous dispersions of starch-soybean oil (SBO) and starch-jojoba oil (JO) composites, prepared by excess steam jet cooking, form effective dry film lubricants when applied as thick coatings to metal surfaces by doctor blade. This application method necessitates long drying times, is wasteful, requ...

  4. AlCu alloy films prepared by the thermal diffusion technique

    SciTech Connect

    Oliva, A.I.; Corona, J.E.; Sosa, V.

    2010-07-15

    100-nm thick films of Al{sub 1-x}Cu{sub x} alloys were prepared on glass substrates by thermal diffusion technique. The Cu atomic concentration was varied from 10% to 90%. Alloys were prepared at different temperatures into a vacuum oven with Argon atmosphere. Two thermal processes were used: i) heating the film at 400 deg. C in a single step, and ii) heating the films in sequential steps at 100, 200, 300 and 400 deg. C. Morphology, electrical resistivity, and crystalline orientation of the alloys were studied. The electrical resistivity and surface roughness of the alloys were found to depend strongly on the atomic composition and the diffusion temperature. However, we did not find differences between samples prepared under the two thermal processes. Alloys prepared with x = 0.6 and x = 0.1-0.3 as Cu at concentration exhibited values on electrical resistivity and surface roughness lower than pure Al. Different phases of the Al{sub 1} {sub -} {sub x}Cu{sub x} films were observed as a function of Cu concentration showing a good agreement with the AlCu phase diagram.

  5. Facile preparation of optically transparent and hydrophobic cellulose nanofibril composite films

    Treesearch

    Yan Qing; Zhiyong Cai; Yiqiang Wu; Chunhua Yao; Qinglin Wu; Xianjun Li

    2015-01-01

    Cellulose nanofibril (CNF) and epoxy nanocomposites with high visible light transmittance and low watersensitivity were manufactured by laminating thin layers of epoxy resin onto CNF films prepared through,pressurized filtration in combination with oven drying. Scanning Electron Microscopy (SEM) studiessuggest that the resin component bonded to the CNF substrate well....

  6. Mechanical and Optical Characterizations of Nanophase Diamond Films Prepared by a Laser Plasma Discharge Source.

    NASA Astrophysics Data System (ADS)

    You, Jonghun

    Films of nanophase diamond can be deposited at room temperature with a laser plasma discharge source of multiply charged carbon ions without the use of any catalyst in the growth mechanism. The beam from a Q-switched Nd:YAG laser is focused on graphite at intensities in excess of 10^{11} Wcm^ {-2} and the resulting plasma ejects carbon ions carrying energies of about 1 keV through a discharge space to the substrate to be coated. The nanophase diamond films that condense are composed of nanometer scale nodules of sp^3 bonded carbon. The high energy of condensation from the laser plasma source provides both the chemical bonding of such films to a wide variety of substrates and for low values of residual compressive stress. In this work, mechanical and optical characterizations of nanophase diamond films were extensively studied. An advanced nanoindentation technique utilizing the NanoTest device was used to measure the hardness of the films prepared by the UT-Dallas laser deposition system and other techniques. The raw data produced was analyzed with a conventional procedure and a hardness value of 125 GPa was obtained. To avoid model dependent interpretation, a differential loading pressure, independent of plastic depth, was used to give a lower limit on the hardness directly for the raw data. Comparable values of this lower limit, near 75 GPa was measured on crystalline diamond prepared by CVD and on nanophase diamond deposited by the laser plasma method. It was shown that the hardness of nanophase diamond films increased with laser intensities used to produce them. The nanoindentation technique was also used to assess the bonding strength of the films. Reproducible discontinuities in the variation of the penetration depth with load were obtained when adhesion failure occurred under indentations. Adhesion strength of films prepared from core and periphery of laser plasma were compared by means of nanoindentation and Rutherford backscattering techniques and

  7. Preparation and pharmaceutical evaluation of glibenclamide slow release mucoadhesive buccal film

    PubMed Central

    Bahri-Najafi, R.; Tavakoli, N.; Senemar, M.; Peikanpour, M.

    2014-01-01

    Buccal mucoadhesive systems among novel drug delivery systems have attracted great attention in recent years due to their ability to adhere and remain on the oral mucosa and to release their drug content gradually. Buccal mucoadhesive films can improve the drug therapeutic effect by enhancement of drug absorption through oral mucosa increasing the drug bioavailability via reducing the hepatic first pass effect. The aim of the current study was to formulate the drug as buccal bioadhesive film, which releases the drug at sufficient concentration with a sustain manner reducing the frequency of the dosage form administration. One of the advantagees of this formulation is better patient compliances due to the ease of administration with no water to swallow the product. The mucoadhesive films of glibenclamide were prepared using hydroxypropyl methylcellulose (HPMC) K4M, K15M and Eudragit RL100 polymers and propylene glycol as plasticizer and co-solvent. Films were prepared using solvent casting method, and were evaluated with regard to drug content, thickness, weight variations, swelling index, tensile strength, ex vivo adhesion force and percentage of in vitro drug release. Films with high concentrations of HPMC K4M and K15M did not have favorable appearance and uniformity. The formulations prepared from Eudragit were transparent, uniform, flexible, and without bubble. The highest and the lowest percentages of swelling were observed for the films containing HPMC K15M and Eudragit RL100, respectively. Films made of HPMC K15M had adhesion force higher than those containing Eudragit RL100. Formulations with Eudragit RL100 showed the highest mean dissolution time (MDT). Drug release kinetics of all formulations followed Higuchi's model and the mechanism of diffusion was considered non-Fickian type. It was concluded that formulations containing Eudragit RL100 were more favorable than others with regard to uniformity, flexibility, rate and percentage of drug release. PMID

  8. Water-based preparation of spider silk films as drug delivery matrices.

    PubMed

    Agostini, Elisa; Winter, Gerhard; Engert, Julia

    2015-09-10

    The main focus of this work was to obtain a drug delivery matrix characterized by biocompatibility, water insolubility and good mechanical properties. Moreover the preparation process has to be compatible with protein encapsulation and the obtained matrix should be able to sustain release a model protein. Spider silk proteins represent exceptional natural polymers due to their mechanical properties in combination with biocompatibility. As both hydrophobic and slowly biodegrading biopolymers, recombinant spider silk proteins fulfill the required properties for a drug delivery system. In this work, we present the preparation of eADF4(C16) films as drug delivery matrices without the use of any organic solvent. Water-based spider silk films were characterized in terms of protein secondary structure, thermal stability, zeta-potential, solubility, mechanical properties, and water absorption and desorption. Additionally, this study includes an evaluation of their application as a drug delivery system for both small molecular weight drugs and high molecular weight molecules such as proteins. Our investigation focused on possible improvements in the film's mechanical properties including plasticizers in the film matrix. Furthermore, different film designs were prepared, such as: monolayer, coated monolayer, multilayer (sandwich), and coated multilayer. The release of the model protein BSA from these new systems was studied. Results indicated that spider silk films are a promising protein drug delivery matrix, capable of releasing the model protein over 90 days with a release profile close to zero order kinetic. Such films could be used for several pharmaceutical and medical purposes, especially when mechanical strength of a drug eluting matrix is of high importance. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Nanostructured TiO2 thin films for DSSCs prepared by sol gel technique

    NASA Astrophysics Data System (ADS)

    Bakar, Siti Noraini Abu; Abdullah, Huda; Mahbor, Kamisah Mohamad

    2017-07-01

    In this research, nanostructured TiO2 thin films were prepared by sol-gel technique for dye-sensitized solar cells (DSSCs) were investigated. The nanostructured thin films were prepared using commercial Titania powder (Degussa P25) and titanium (IV) ethoxide (TEOT). The resulting solution were spin-coated on pieces of indium-doped tin oxide (InO2:Sn, ITO) transparent glass (8 Ω/sq, TEC GlassTM) with an area of 10 × 10 mm2 at a rate of 2000 rpm for 30 seconds. The films were annealed in furnace at 450 °C for 60 min. The working electrode was then immersed in the solution of N-719 (Ruthenium) dye at room temperature for 24 h. A thin film of platinum (Pt) was deposited on the ITO-glass substrate as the counter electrode using print-screen technique. The structures, morphological and optical properties of the films, were examined using X-Ray Diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM) and UV-VIS spectrometer respectively. The XRD results showed that the crystalline phase of the film was anatase. The micrograph obtained using FESEM demonstrated that the prepared TiO2 film has a nanosructured characteristic. The photovoltaic properties of DSSC was studied under an incident irradiation of 100 mW/cm2. The energy conversion efficiency (η) of the DSSC with nanostuctured TiO2 (P25) and TiO2 was 0.3% and 0.2 % respectively.

  10. Superconducting Properties of Htsc Thin Films Prepared in Situ by Single Target Deposition

    NASA Astrophysics Data System (ADS)

    Geerk, J.; Xi, X. X.; Li, H. C.; Guan, W. Y.; Kus, P.; Höbel, M.; Linker, G.; Meyer, O.; Ratzel, F.; Schultheiss, C.; Smithey, R.; Strehlau, B.; Weschenfelder, F.

    Thin films of ReBaCuO (Re=Y, Gd) and of BiCaSrCuO have been deposited onto A12O3, MgO, SrTiO3, Si and ZrO2 substrates by planar and inverted cylindrical magnetron sputtering. The main advantage of this preparation technique is the high reproducibility allowing detailed and systematic studies of the film properties as a function of deposition parameters. Optimum deposition parameters were a high oxygen partial pressure of 2×10-1 Torr in an oxygen-argon mixture and substrate temperatures near 800°C. Except for the substrate Si the films grow highly textured on all substrates. For the 1-2-3 material zero resistance is obtained near 90 K for the case of textured growth. For Si the best film showed zero resistance near 84 K. High critical currents between 4×105 and 5.5×106 A/cm2 were determined for films of the 1-2-3 material on the substrates MgO, ZrO2 and SrTiO3. On films SrTio3 tunnel junctions with Pb and In counterelectrodes could be prepared which showed a gap-like feature in their current-voltage characteristic. These junctions could be prepared with great reproducibility and experimental arguments could be provided which show that this gap-like feature is due to a superconducting density of states effect. Finally, first results are presented on YBaCuO thin films which were deposited by a novel ablation device which uses a pulsed electron beam instead of the laser beam.

  11. [SERS spectra of Xanthomonas oryzae pv. Oryzae (Xoo) on nano silver film prepared by electrolysis method].

    PubMed

    Kang, Yi-Pu; Si, Min-Zhen; Li, Qing-Yu; Huang, Qiong; Liu, Ren-Ming

    2010-02-01

    The nano silver film was prepared by electrolysis method using silver nitrate and polyvinyl alcohol (PVA) in deionized water as the electrolyte, with four glass slides put in the electrolyte and two silver rods dipped into the electrolyte as the anode and cathode. A direct current was applied to the rods, then the four glass slides stayed in the silver colloids. Thus the authors got the nano silver film. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) were employed to detect the silver particles in the silver colloids and on the nano silver film. From the SEM we can see that the silver particles on the film formed different layers. In one layer, the distance between two particles was about 100 nm. The samples of Xanthomonas oryzae pv. Oryzae (Xoo) were 7 different kinds of bacterial blight, namely 1-YN1, 2-YN7, 3-YN11, 4-GD414, 5-SCYC6, 6-HEN11 and 7-FWJ. Because the silver particles in the colloids were aggregated on the film, there was large electromagnetic potentiation. So the SERS spectra of Xoo were perfect. The authors used the area analytical method to distinguish the different kinds of Xoo. The silver film prepared by electrolysis was cheap and active, the preparation time of the samples was short, and any normal chemistry lab can make it, which can find excellent application to detecting the Xoo in agriculture. On the other hand, this film is active on biomolecules and bioorganism, which may be a new kind of SERS fundus to explain the creation of the SERS. Further study was under way.

  12. Properties of Cr2AlC MAX phase thin films prepared by reactive magnetron sputtering

    NASA Astrophysics Data System (ADS)

    Buck, Zachary; Donato, Tyler; Rotella, Christopher; Lunk, Carl; Lofland, S. E.; Hettinger, J. D.

    2012-02-01

    Mn+ 1AXn (MAX) phases, where n is 1, 2, and 3, M is an early transition metal, A is an A-group element, and X is either C or N, are ternary carbides with unique properties such as low density, easy machinability, and good oxidation resistance. The MAX phase Cr2AlC is of particular interest for industrial applications to its excellent high-temperature oxidation resistance and relatively low synthesis temperature. We prepared Cr2AlC thin films on c-axis oriented single crystal Al2O3, glassy carbon and Si thermal oxide substrates using reactive magnetron sputtering as precursor materials for carbide-derived carbon (CDC) films for ``on-chip'' supercapacitors. Film deposition was optimized using elemental composition data obtained by WDXRF. Optimized films were characterized using XRD and scanning electron microscopy. It was found that textured Cr2AlC films only form when the composition was Al-rich allowing the formation of a Cr5Al8 interfacial layer. As film composition was optimized, the interfacial layer did not form but the XRD peaks associated with the Cr2AlC also decreased in magnitude. Extremely high-textured films were grown when a thin buffer layer of CrAl2 was deposited on the substrate before depositing the Cr2AlC films. This result suggests that Cr2AlC films may not be ideal for CDC applications since the films may ``lift-off'' during conversion due to the existence of the naturally occurring buffer-layer.

  13. Boron doping effects in electrochromic properties of NiO films prepared by sol-gel

    SciTech Connect

    Lou, Xianchun; Zhao, Xiujian; He, Xin

    2009-12-15

    In this paper, NiO films doped with B{sub 2}O{sub 3} were first prepared by sol-gel. The effects of boron content on the structure and electrochromic properties of NiO films were studied with X-ray diffraction (XRD), transmission electron microscopy (TEM), cyclic voltammetric (CV) and UV-vis spectrophotometer, respectively. In addition, the roughness and phase of the bleached/colored were studied by atom force microscopy (AFM). B-doped prevent the crystallization of the films. The colored state transmittance could be significantly lowered when the boron added. The NiO film doped with boron exhibited a noticeable electrochromism with a variation of transmittance up to {proportional_to}60% at the wavelength range of 300-500 nm. (author)

  14. Preparation of SiN x film by pulsed laser ablation in nitrogen gas ambient

    NASA Astrophysics Data System (ADS)

    Umezu, I.; Yamaguchi, T.; Kohno, K.; Inada, M.; Sugimura, A.

    2002-09-01

    Silicon nitride films were synthesized by reactive pulsed laser ablation (PLA) of a Si target in N 2 gas atmosphere. At different laser fluences and N 2 gas pressures the infrared absorption peak attributed to Si-N bond was evaluated. The nitrogen concentration in the film increased with the increasing fluence. Nitrogen concentration depended also on N 2 gas pressure; it increased as N 2 pressure increase up to 10 Pa and then it decreased with further increasing N 2 gas pressure. These results indicate that decomposition of N 2 molecules and collisions of SiN x clusters with N 2 molecules are essential to prepare silicon nitride films by PLA method. The PLA is a promising method to fabricate nitrogen rich silicon nitride films without using poisonous gases such as silane and ammonia.

  15. Preparation of photocatalytic anatase nanowire films by in situ oxidation of titanium plate.

    PubMed

    Wu, Yahui; Long, Mingce; Cai, Weimin; Dai, Sidi; Chen, Chao; Wu, Deyong; Bai, Jing

    2009-05-06

    Photocatalytic anatase TiO2 nanowire thin films have been prepared by in situ oxidation of Ti plate in a mixture solution of concentrated H(2)O(2) and NaOH, followed by proton exchange and calcination. The morphologies and properties of the titanate and titania films have been investigated by means of field emission scanning electron microscopy, energy-dispersive x-ray spectrometry, high resolution transmission electron microscopy, x-ray diffraction and Raman spectrometry. The mechanism of formation of the porous microstructure has been discussed; it is the result of the balance between dissolution and precipitation. And sodium ions in the solution are needed to combine with titanate species for the nanowire formation. The anatase TiO2 nanowire thin films exhibited enhanced photocatalytic activity and stability in phenol degradation. The combination effects of the porous morphology and nanowire characteristics are favorable for improved photocatalytic performance. This novel nanowire film is promising for practical aqueous purification.

  16. Photocatalysts of Cr Doped TiO2 Film Prepared by Micro Arc Oxidation

    NASA Astrophysics Data System (ADS)

    Wan, Li; Li, Jian-feng; Feng, Jia-you; Sun, Wei; Mao, Zong-qiang

    2008-10-01

    A series of Cr doped TiO2 films were prepared by micro arc oxidation (MAO) using an electrolyte of Na3PO4+K2Cr2O7. X-ray diffraction and scanning electron microscopy revealed that the films mainly consisted of anatase phase with a porous surface morphology. The films have an excellent photocatalytic effect for degradation of methylene blue and decomposition of water under visible light illumination. This arises from the formation of Cr3+/Cr4+ and oxygen vacancy energy levels owing to Cr doping. The former reduces the electron-hole recombination chance, while the latter generates a new gap between the conduction band (CB) and valence band (VB) of TiO2, which lowers the photo energy of the excited electron in the VB to the oxygen vacancy states. The mechanisms for film synthesis during the MAO process are also presented.

  17. White light emission from silicon oxycarbide films prepared by using atmospheric pressure microplasma jet

    SciTech Connect

    Ding Yi; Shirai, Hajime

    2009-02-15

    An atmospheric pressure microplasma jet was employed as a deposition tool to fabricate silicon oxycarbide films from tetraethoxysilane-argon (Ar) mixture gas at room temperature. Resultant films exhibit intense visible emission under a 325 nm excitation which appears white to naked eyes in the range from {approx}1.75 to {approx}3.5 eV at room temperature. The origin of photoluminescence is attributed to the electron-hole pair recombination through neutral oxygen vacancies (NOVs) in the film. The density of NOV defects was found in the range from 3.48x10{sup 15} to 2.23x10{sup 16} cm{sup -3}. The photoluminescence quantum efficiencies were estimated to be 1.48%-4.15%. Present experiment results demonstrate that the silicon oxycarbide films prepared by using atmospheric pressure microplasma jet would be a competitive candidate for the development of white light emission devices.

  18. Thin-film sensors for space propulsion technology: Fabrication and preparation for testing

    NASA Technical Reports Server (NTRS)

    Kim, Walter S.; Hepp, Aloysius F.

    1989-01-01

    The goal of this work is to develop and test thin-film thermocouples for Space Shuttle Main Engine (SSME) components. Thin-film thermocouples have been developed for aircraft gas turbine engines and are in use for temperature measurement on turbine blades up to 1800 F. Established aircraft engine gas turbine technology is currently being adapted to turbine engine blade materials and the environment encountered in the SSME, especially severe thermal shock from cryogenic fuel to combustion temperatures. Initial results using coupons of MAR M-246 (+Hf) and PWA 1480 have been followed by fabrication of thin-film thermocouples on SSME turbine blades. Current efforts are focused on preparing for testing in the Turbine Blade Tester at the NASA Marshall Space Flight Center (MSFC). Future work will include testing of thin-film thermocouples on SSME blades of single crystal PWA 1480 at MSFC.

  19. Chalcogenide-based thin film sensors prepared by pulsed laser deposition technique

    NASA Astrophysics Data System (ADS)

    Schubert, J.; Schöning, M. J.; Schmidt, C.; Siegert, M.; Mesters, St.; Zander, W.; Kordos, P.; Lüth, H.; Legin, A.; Mourzina, Yu. G.; Seleznev, B.; Vlasov, Yu. G.

    One advantage of the pulsed laser deposition (PLD) method is the stoichiometric transfer of multi-component target material to a given substrate. This advantage of the PLD determined the choice to prepare chalco-genide-based thin films with an off-axis geometry PLD. Ag-As-S and Cu-Ag-As-Se-Tetargets were used to deposit thin films on Si substrates for an application as a heavy metal sensing device. The films were characterized by means of Rutherford backscattering spectrometry (RBS), transmission electron microscopy (TEM), and electrochemical measurements. The same stoichiometry of the films and the targets was confirmed by RBS measurements. We observed a good long-term stability of more than 60 days and a nearly Nernstian sensitivity towards Pb and Cu, which is comparable to bulk sensors.

  20. Microstructure and electrical properties Of PMNT thin films prepared by a modified sol-gel process

    NASA Astrophysics Data System (ADS)

    Liu, Aiyun; Han, Hailong; Wei, Linlin; Wang, Peng; Lin, Fangting; Shi, Wangzhou; Meng, Xiangjian; Sun, Jinglan; Chu, Junhao; Jing, Chengbin

    2013-12-01

    0.7Pb(Mg1/3Nb2/3)O3-0.3PbTiO3 (PMNT) thin films were prepared on (111)Pt/Ti/SiO2/Si substrate by a modified sol-gel process with Nb2O5 as the niobium source. XRD analysis shows that PMNT thin films with pure perovskite were obtained by spin-coating and annealing at 700°C for 20 minutes. The remanent polarization and coercive field of the PMNT thin films are about 7.69μC/cm2 and 80.75kV/cm, respectively. The dielectric and C-V curve of PMNT thin films are also investigated. The dielectric constant ( ɛr ) reaches 935 and the dissipation factor (tanδ)is about 0.04 at 1kHz.

  1. Tuneable light-emitting carbon-dot/polymer flexible films prepared through one-pot synthesis.

    PubMed

    Bhunia, Susanta Kumar; Nandi, Sukhendu; Shikler, Rafi; Jelinek, Raz

    2016-02-14

    Development of efficient, inexpensive, and environmentally-friendly light emitters, particularly devices that produce white light, have drawn intense interest due to diverse applications in the lighting industry, photonics, solar energy, and others. We present a simple strategy for the fabrication of flexible transparent films exhibiting tuneable light emission through one-pot synthesis of polymer matrixes with embedded carbon dots assembled in situ. Importantly, different luminescence colours were produced simply by preparing C-dot/polymer films using carbon precursors that yielded C-dots exhibiting distinct fluorescence emission profiles. Furthermore, mixtures of C-dot precursors could be also employed for fabricating films exhibiting different colours. In particular, we successfully produced films emitting white light with attractive properties (i.e."warm" white light with a high colour rendering index) - a highly sought after goal in optical technologies.

  2. Antimony sulfide thin films prepared by laser assisted chemical bath deposition

    NASA Astrophysics Data System (ADS)

    Shaji, S.; Garcia, L. V.; Loredo, S. L.; Krishnan, B.; Aguilar Martinez, J. A.; Das Roy, T. K.; Avellaneda, D. A.

    2017-01-01

    Antimony sulfide (Sb2S3) thin films were prepared by laser assisted chemical bath deposition (LACBD) technique. These thin films were deposited on glass substrates from a chemical bath containing antimony chloride, acetone and sodium thiosulfate under various conditions of normal chemical bath deposition (CBD) as well as in-situ irradiation of the chemical bath using a continuous laser of 532 nm wavelength. Structure, composition, morphology, optical and electrical properties of the Sb2S3 thin films produced by normal CBD and LACBD were analyzed by X-Ray diffraction (XRD), Raman Spectroscopy, Atomic force microscopy (AFM), X-Ray photoelectron spectroscopy (XPS), UV-vis spectroscopy and Photoconductivity. The results showed that LACBD is an effective synthesis technique to obtain Sb2S3 thin films for optoelectronic applications.

  3. Design and preparation of film for microsphere based optical super-resolution imaging

    NASA Astrophysics Data System (ADS)

    Pang, Hui; Du, Chunlei; Qiu, Qi; Yin, Shaoyun; Zhang, Man; Deng, Qiling

    2014-08-01

    In this paper, a novel thin film was proposed for optical super-resolution imaging, which contains a layer of closely-arranged barium titanate glass microsphere with diameter about 30-100μm embedded in a transparent polydimethylsiloxane soft mold. Then the imaging mechanism was analyzed by the finite-difference time-domain (FDTD) simulation and spectrum analysis method. Finally, the thin film was prepared and used to image the sample with sub-wavelength feature to confirm the capability of super-resolution imaging. The experimental result shows that an irresolvable Blu-ray DVD disk with feature size of 300nm can be resolved by placing a thin-film on its surface and then look through it with a conventional microscope. The thin film presented here is flexible, lightweight, easy to carry and can be used in the nanophotonics, nanoplasmonics, and biomedical imaging areas.

  4. Highly photoconductive amorphous carbon nitride films prepared by cyclic nitrogen radical sputtering

    NASA Astrophysics Data System (ADS)

    Katsuno, T.; Nitta, S.; Habuchi, H.; Stolojan, V.; Silva, S. R. P.

    2004-10-01

    We report on the growth of amorphous carbon nitride films (a-CNx) showing the highest conductivity to date. The films were prepared using a layer-by-layer method (a-CNx:LL), by the cyclical nitrogen radical sputtering of a graphite radical, alternated with a brief hydrogen etch. The photosensitivity S of these films is 105, defined as the ratio of the photoconductivity σp to the dark conductivity σd and is the highest value reported thus far. We believe that the carriers generated by the monochromatic light (photon energy 6.2eV) in the a-CNx:LL films are primarily electrons, with the photoconductivity shown to increase with substrate deposition temperature.

  5. TiO2 thin films prepared by sol - gel method

    NASA Astrophysics Data System (ADS)

    Suciu, R. C.; Indrea, E.; Silipas, T. D.; Dreve, S.; Rosu, M. C.; Popescu, V.; Popescu, G.; Nascu, H. I.

    2009-08-01

    There is a growing awareness that titania (TiO2) and TiO2-based oxide systems are the most promising candidates for the development of photoelectrodes for photoelectrochemical cell (PEC) for solar-hydrogen production [1]. The PEC is equipped with a single photoelectrode (photoanode) and cathode, both of which are immersed in an aqueous electrolyte. In this work we present a sol-gel method to prepare TiO2 thin films on ITO using tetraisopropoxides of titanium, acetylacetone, 1-butanol and Tween 80 as surfactant. The films were deposited on ITO coated glass slides by spray pyrolysis. UV-VIS spectra and fluorescence measurements were made for the solutions and films. X-ray diffraction was used for structural investigations and the morphology of the film was studied by Scanning Electron Microscopy.

  6. Highly photoconductive amorphous carbon nitride films prepared by cyclic nitrogen radical sputtering

    SciTech Connect

    Katsuno, T.; Nitta, S.; Habuchi, H.; Stolojan, V.; Silva, S.R.P.

    2004-10-04

    We report on the growth of amorphous carbon nitride films (a-CN{sub x}) showing the highest conductivity to date. The films were prepared using a layer-by-layer method (a-CN{sub x}:LL), by the cyclical nitrogen radical sputtering of a graphite radical, alternated with a brief hydrogen etch. The photosensitivity S of these films is 10{sup 5}, defined as the ratio of the photoconductivity {sigma}{sub p} to the dark conductivity {sigma}{sub d} and is the highest value reported thus far. We believe that the carriers generated by the monochromatic light (photon energy 6.2 eV) in the a-CN{sub x}:LL films are primarily electrons, with the photoconductivity shown to increase with substrate deposition temperature.

  7. YBCO and LSMO nano-films and sandwiches prepared by magnetron sputtering

    NASA Astrophysics Data System (ADS)

    Nurgaliev, T.; Mateev, E.; Blagoev, B.; Miteva, S.; Neshkov, L.; Strbik, V.; Uspenskaya, L. S.; Benacka, S.; Chromik, S.; Nedkov, I.

    2010-06-01

    DC and RF magnetron sputtering techniques were used for growing nano-films (t<100 nm) of high temperature superconducting (HTS) YBa2Cu3O7 (YBCO) and ferromagnetic (FM) manganite La0.7Sr0.3Mn03 (LSMO) materials on LaAlO3 (LAO) and Al2O3 (ALO) substrates as well as for preparing of single-, double- and three-layer structures in different areas of the same substrates. The procedure allowed growing of structures on LAO substrates where the critical temperature of YBCO thin film components was more than 84 K. The LSMO films grown ALO substrates were ferromagnetic while the YBCO films grown on LSMO/ALO did not demonstrate superconductivity.

  8. Preparation and Analysis of Platinum Thin Films for High Temperature Sensor Applications

    NASA Technical Reports Server (NTRS)

    Wrbanek, John D.; Laster, Kimala L. H.

    2005-01-01

    A study has been made of platinum thin films for application as high temperature resistive sensors. To support NASA Glenn Research Center s high temperature thin film sensor effort, a magnetron sputtering system was installed recently in the GRC Microsystems Fabrication Clean Room Facility. Several samples of platinum films were prepared using various system parameters to establish run conditions. These films were characterized with the intended application of being used as resistive sensing elements, either for temperature or strain measurement. The resistances of several patterned sensors were monitored to document the effect of changes in parameters of deposition and annealing. The parameters were optimized for uniformity and intrinsic strain. The evaporation of platinum via oxidation during annealing over 900 C was documented, and a model for the process developed. The film adhesion was explored on films annealed to 1000 C with various bondcoats on fused quartz and alumina. From this compiled data, a list of optimal parameters and characteristics determined for patterned platinum thin films is given.

  9. Characterization of ZnO Thin Films Prepared by Thermal Oxidation of Zn

    NASA Astrophysics Data System (ADS)

    Bouanane, I.; Kabir, A.; Boulainine, D.; Zerkout, S.; Schmerber, G.; Boudjema, B.

    2016-07-01

    Zinc oxide thin films were prepared by thermal oxidation of zinc films at a temperature of 500°C for 2 h. The Zn films were deposited onto glass substrates by magnetron RF sputtering. The sputtering time varied from 2.5 min to 15 min. The physico-chemical characterization of the ZnO films was carried out depending on the Zn sputtering time. According to x-ray diffraction, ZnO films were polycrystalline and the Zn-ZnO phase transformation was direct. The mean transmittance of the ZnO films was around 80% and the band gap increased from 3.15 eV to 3.35 eV. Photoluminescence spectra show ultraviolet, visible, and infrared emission bands. The increase of the UV emission band was correlated with the improvement of the crystalline quality of the ZnO films. The concentration of native defects was found to decrease with increasing Zn sputtering time. The decrease of the electrical resistivity as a function of Zn sputtering time was linked to extrinsic hydrogen-related defects.

  10. Electroplated Fe-Co-Ni films prepared from deep-eutectic-solvent-based plating baths

    NASA Astrophysics Data System (ADS)

    Yanai, Takeshi; Shiraishi, Kotaro; Akiyoshi, Toshiki; Azuma, Keita; Watanabe, Yoshimasa; Ohgai, Takeshi; Morimura, Takao; Nakano, Masaki; Fukunaga, Hirotoshi

    2016-05-01

    We fabricated soft magnetic films from DES-based plating baths, and investigated magnetic properties of the plated films. The plating baths were obtained by stirring the mixture of choline chloride, ethylene glycol, FeCl2 ṡ 4H2O, NiCl2 ṡ 6H2O and CoCl2 ṡ 6H2O. The composition of the electroplated film depended on the amount of the reagent in the plating bath, and we consequently obtained the films with various composition. The current efficiency of the plating process shows high values (> 88 %) in the wide composition range. The soft magnetic films with low coercivity were obtained at the Fe compositions of ≈ 30 at.% and > 80 at.%, and we found that low coercivity could be realized by the control of the film composition. We also found that the Fe-rich films prepared from DES-based plating bath have some advantages as a soft magnetic phase for a nanocomposite magnet due to their high saturation magnetization and very fine crystal structure.

  11. Electrical and structural properties of the Ta/Ag thin films prepared by DC magnetron sputtering

    NASA Astrophysics Data System (ADS)

    Moghri Moazzen, M. A.; Taiebyzadeh, P.; Borghei, S. M.

    2017-07-01

    Tantalum on silver (Ta/Ag) thin films have quickly increased into high research for applied science with the promise of suitable for high temperatures environments and microsystems for electronics applications. Ag and Ta/Ag thin films were deposited on silicon substrates by dc magnetron sputtering method. We choose the dc magnetron sputtering method because it has many advantages, such as high growth rate, the possibility of large area deposition, and low cost. X-ray diffraction (XRD) analysis and four point probe (FPP) were used for determining the prepared samples. For Ag thin film deposited in room temperature, there are no peaks corresponding to Ag in the XRD pattern which demonstrates amorphous structure. Also, the XRD pattern of Ta/Ag thin film illustrates that the peak of Ta has grown to the crystal direction (002), which shows that the structure of deposited Ta layer on Ag thin film becomes a crystalline state from amorphous state. The relationship between thin film resistivity and Ta/Ag film thicknesses are investigated in this paper.

  12. Structural properties of aluminum-nitrogen films prepared at low temperature

    NASA Astrophysics Data System (ADS)

    Ribeiro, C. T. M.; Alvarez, F.; Zanatta, A. R.

    2002-08-01

    Aluminum-nitrogen thin films have been obtained under well-controlled conditions by ion-beam-assisted deposition (IBAD). The films were deposited on crystalline silicon and sapphire substrates at relative low temperature (approx325 K). Taking advantage of the ion energy control provided by the IBAD technique, the films were prepared with N2+ ions with energies ranging from 100 to 300 eV. After deposition, the films were investigated by in situ x-ray photoelectron spectroscopy, ex situ by optical spectroscopy, and x-ray diffraction. Detailed Raman scattering measurements in the 100-2500 cm-1 wave number range were also performed revealing interesting features related to the atomic composition and structure of the films. The Raman data suggest that a misidentification of some vibration modes can lead to incorrect interpretations of the crystalline quality of aluminum-nitrogen films. Finally, the results indicate the suitability of IBAD to produce crystalline AlN films at considerably lower temperatures.

  13. Preparation and antifouling property of polyurethane film modified by chondroitin sulfate

    NASA Astrophysics Data System (ADS)

    Yuan, Huihui; Xue, Jing; Qian, Bin; Chen, Huaying; Zhu, Yonggang; Lan, Minbo

    2017-02-01

    An antifouling polyurethane film modified by chondroitin sulfate (PU-CS) was prepared by chemical grafting with N-Boc-1,3-propanediamine as a spacer. The different mass fraction of N-Boc-1,3-propanediamine was investigated to obtain PU-CS films with different CS grafting density. The surface properties of PU-CS films were comprehensively characterized. Proteins adsorption and glycosaminoglycans adhesion on films were evaluated. Moreover, inorganic salt deposition on film with highest CS grafting density (3.70 μg/cm2) was briefly investigated. The results showed that the increase of CS grafting density improved not only the hydrophilicity but the antifouling performance of films. The best antifouling film reduced the adsorption of fibrinogen (BFG), human serum albumin (HSA) and lysozyme (LYS) by 81.4%, 95.0% and 76.5%, respectively, and the adhesion of chondroitin (CS), heparin (HP) and hyaluronic acid (HA) by 70.6%, 87.4% and 81.3%, respectively. In addition, the co-adsorption of proteins and glycosaminoglycans reduced up to 86.9% and 75.5%, respectively. Changes in inorganic salt deposition after co-adsorption of proteins and glycosaminoglycans on PU-CS(3) suggested that the proteins promoted the inorganic salt deposition, while glycosaminoglycans inhibited the crystal growth. The negatively charged polysaccharides might promote the generation of smaller crystals which could be conducive to provide theoretical and practical guide to develop novel urinary stents with significant anti-encrustation properties.

  14. Heavy-ion beam induced effects in enriched gadolinium target films prepared by molecular plating

    NASA Astrophysics Data System (ADS)

    Mayorov, D. A.; Tereshatov, E. E.; Werke, T. A.; Frey, M. M.; Folden, C. M.

    2017-09-01

    A series of enriched gadolinium (Gd, Z = 64) targets was prepared using the molecular plating process for nuclear physics experiments at the Cyclotron Institute at Texas A&M University. After irradiation with 48Ca and 45Sc projectiles at center-of-target energies of Ecot = 3.8-4.7 MeV/u, the molecular films displayed visible discoloration. The morphology of the films was examined and compared to the intact target surface. The thin films underwent a heavy-ion beam-induced density change as identified by scanning electron microscopy and α-particle energy loss measurements. The films became thinner and more homogenous, with the transformation occurring early on in the irradiation. This transformation is best described as a crystalline-to-amorphous phase transition induced by atomic displacement and destruction of structural order of the original film. The chemical composition of the thin films was surveyed using energy dispersive spectroscopy and X-ray diffraction, with the results confirming the complex chemistry of the molecular films previously noted in other publications.

  15. Preparation and antimicrobial assay of ceramic brackets coated with TiO2 thin films

    PubMed Central

    Cao, Shuai; Wang, Ye; Cao, Lin; Wang, Yu; Lin, Bingpeng; Lan, Wei

    2016-01-01

    Objective Different methods have been utilized to prevent enamel demineralization and other complications during orthodontic treatment. However, none of these methods can offer long-lasting and effective prevention of orthodontic complications or interventions after complications occur. Considering the photocatalytic effect of TiO2 on organic compounds, we hoped to synthesize a novel bracket with a TiO2 thin film to develop a photocatalytic antimicrobial effect. Methods The sol-gel dip coating method was used to prepare TiO2 thin films on ceramic bracket surfaces. Twenty groups of samples were composed according to the experimental parameters. Crystalline structure and surface morphology were characterized by X-ray diffraction and scanning electron microscopy, respectively; film thickness was examined with a surface ellipsometer. The photocatalytic properties under ultraviolet (UV) light irradiation were analyzed by evaluating the degradation ratio of methylene blue (MB) at a certain time. Antibacterial activities of selected thin films were also tested against Lactobacillus acidophilus and Candida albicans. Results Films with 5 coating layers annealed at 700℃ showed the greatest photocatalytic activity in terms of MB decomposition under UV light irradiation. TiO2 thin films with 5 coating layers annealed at 700℃ exhibited the greatest antimicrobial activity under UV-A light irradiation. Conclusions These results provide promising guidance in prevention of demineralization by increasing antimicrobial activities of film coated brackets. PMID:27226960

  16. High T(sub c) thin film superconductors: Preparation, patterning and characterization

    NASA Astrophysics Data System (ADS)

    Azoulay, J.

    A conventional oil-pumped vacuum system equipped with resistively heated tungsten boat sources was used for evaporation of bismuth- or yttrium-based cuprates for high T(sub c) thin film superconductors. A well-ground mixture with atomic proportions of bismuth, SrF2, CaF2 and copper for bismuth-based material, and of YF3, BaF2 and copper for yttrium-based material, was inserted into the boat and then resistively evaporated onto different substrates such as MgO, ZrO2 and SrTiO3 kept at room temperature. Yttrium-based thin films were found to have a better quality upon reduction of fluorine in the constituents. Thus, films prepared with an yttrium BaF2 and copper mixture show a metallic-like behavior, sharper transition and higher zero-resistance temperature as compared with that of films obtained by using a YF2 constiuent instead of yttrium. Bismuth-based thin films were found to lose bismuth during heat treatment unless the copper constiuent ended the evaporation process and was subsequently fully oxidized at 400 C. Bismuth-based patterned films were easily obtained by using a lift-off photolithographic method. Typical thickness of the films was measured to be about 0.5 micron after heat treatment.

  17. Marangoni effect induced macro porous surface films prepared through a facile sol-gel route.

    PubMed

    Khan, Shahid; Wang, Kangkai; Yuan, Guangzhong; Haq, Mahmood Ul; Wu, Zhizheng; Usman, Muhammad; Song, Chenlu; Han, Gaorong; Liu, Yong

    2017-07-13

    Based on TiO2 as a model system, the sol-gel one step facile method is established to fabricate the macro-porous morphology films on the basis of Marangoni effect. In this proposed mechanism, the binary mixture of hydrophilic CuCl2 and lipophilic Ti-O network is used in sol to produce phase separation. A suitable evaporation rate in the gel film process leads to the macro-porous film due to Marangoni effect. It is observed that the macro-porous morphology of the film sustains during the annealing process, which suggests the creation of porous surface morphology in gel film stage rather than due to annealing. To analyze the preparation mechanism, the sol-gel process and microstructure of films are examined using TG-DTA, SEM, TEM, XRD, Raman, UV-Vis, XPS and FTIR. Furthermore, the optical-thermal properties are studied for the potential applications of such porous surface films as solar selective absorber.

  18. Preparation and properties of Starch-g-PLA/poly(vinyl alcohol) composite film.

    PubMed

    Hu, Yingmo; Wang, Qingling; Tang, Mingru

    2013-07-25

    Starch/lactic acid graft copolymer (Starch-g-PLA) was prepared by the in situ copolymerization of starch grafted with lactic acid catalyzed with sodium hydroxide, and then mixed with poly(vinyl alcohol) (PVA) to get composite films. The structures of the graft copolymer and composite films were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The mechanical properties, water resistance, and thermal stability were also investigated. It was found that the compatibility of Starch-g-PLA and PVA was better than that of starch and PVA in the composite films. The tensile strength and elongation at break of the Starch-g-PLA/PVA composite film increased by 69.15% and 84.22%, respectively, while the water absorption decreased by 50.39%, which overcame the shortcomings of hydrophilicity and poor mechanical properties of Starch/PVA film. Thermogravimetric analysis (TGA) also showed that the thermal stability of Starch-g-PLA/PVA film was improved compared with Starch/PVA film. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Piezoelectricity of ZnO Films Prepared by Sol-Gel Method

    NASA Astrophysics Data System (ADS)

    Zhang, Ke-ming; Zhao, Ya-pu; He, Fa-quan; Liu, Dong-qing

    2007-12-01

    ZnO piezoelectric thin films were prepared on crystal substrate Si(111) by sol-gel technology, then characterized by scanning electron microscopy, X-ray diffraction and atomic force microscopy (AFM). The ZnO films characterized by X-ray diffraction are highly oriented in (002) direction with the growing of the film thickness. The morphologies, roughness and grain size of ZnO film investigated by AFM show that roughness and grain size of ZnO piezoelectric films decrease with the increase of the film thickness. The roughness dimension is 2.188-0.914 nm. The piezoelectric coefficient d33 was investigated with a piezo-response force microscope (PFM). The results show that the piezoelectric coefficient increases with the increase of thickness and (002) orientation. When the force reference is close to surface roughness of the films, the piezoelectric coefficient measured is inaccurate and fluctuates in a large range, but when the force reference is big, the piezoelectric coefficient d33 changes little and ultimately keeps constant at a low frequency.

  20. Fluorinated graphene dielectric films obtained from functionalized graphene suspension: preparation and properties.

    PubMed

    Nebogatikova, N A; Antonova, I V; Prinz, V Ya; Kurkina, I I; Vdovin, V I; Aleksandrov, G N; Timofeev, V B; Smagulova, S A; Zakirov, E R; Kesler, V G

    2015-05-28

    In the present study, we have examined the interaction between a suspension of graphene in dimethylformamide and an aqueous solution of hydrofluoric acid, which was found to result in partial fluorination of suspension flakes. A considerable decrease in the thickness and lateral size of the graphene flakes (up to 1-5 monolayers in thickness and 100-300 nm in diameter) with increasing duration of fluorination treatment is found to be accompanied by a simultaneous transition of the flakes from the conducting to the insulating state. Smooth and uniform insulating films with a roughness of ∼2 nm and thicknesses down to 20 nm were deposited from the suspension on silicon. The electrical and structural properties of the films suggest their use as insulating elements in thin-film nano- and microelectronic device structures. In particular, it was found that the films prepared from the fluorinated suspension display rather high breakdown voltages (field strength of (1-3) × 10(6) V cm(-1)), ultralow densities of charges in the film and at the interface with the silicon substrate in metal-insulator-semiconductor structures (∼(1-5) × 10(10) cm(-2)). Such excellent characteristics of the dielectric film can be compared only to well-developed SiO2 layers. The films from the fluorinated suspension are cheap, practically feasible and easy to produce.

  1. Facile approach to prepare drug-loading film from hemicelluloses and chitosan.

    PubMed

    Guan, Ying; Qi, Xian-Ming; Chen, Ge-Gu; Peng, Feng; Sun, Run-Cang

    2016-11-20

    This study introduces a facile and green route to fabricate film from bio-based polymers. The film has been prepared by the cross-linking reaction of quaternized hemicelluloses (QH) and chitosan (CHO) with epichlorohydrin (ECH) as crosslinker. It exhibits an excellently mechanical performance as a result of its high tensile strength (up to 37MPa). Importantly, the roughness of film was 2-5nm in the area of 400nm, and smooth surface with pores were presented on the film based on the results of scanning electron microscope (SEM) and atomic force microscope (AFM). Ciprofloxacin was utilized as a mode compound to investigate the loading behavior of the film, and the highest loading concentration was about 18%. The drug release was about 20% in film1 in comparison to only 15% in film3 within 48h. Furthermore, the results of a 293T cell viability assay indicated its good biocompatibility and non-toxicity. Copyright © 2016 Elsevier Ltd. All rights reserved.

  2. Tuneable light-emitting carbon-dot/polymer flexible films prepared through one-pot synthesis

    NASA Astrophysics Data System (ADS)

    Bhunia, Susanta Kumar; Nandi, Sukhendu; Shikler, Rafi; Jelinek, Raz

    2016-02-01

    Development of efficient, inexpensive, and environmentally-friendly light emitters, particularly devices that produce white light, have drawn intense interest due to diverse applications in the lighting industry, photonics, solar energy, and others. We present a simple strategy for the fabrication of flexible transparent films exhibiting tuneable light emission through one-pot synthesis of polymer matrixes with embedded carbon dots assembled in situ. Importantly, different luminescence colours were produced simply by preparing C-dot/polymer films using carbon precursors that yielded C-dots exhibiting distinct fluorescence emission profiles. Furthermore, mixtures of C-dot precursors could be also employed for fabricating films exhibiting different colours. In particular, we successfully produced films emitting white light with attractive properties (i.e. ``warm'' white light with a high colour rendering index) - a highly sought after goal in optical technologies.Development of efficient, inexpensive, and environmentally-friendly light emitters, particularly devices that produce white light, have drawn intense interest due to diverse applications in the lighting industry, photonics, solar energy, and others. We present a simple strategy for the fabrication of flexible transparent films exhibiting tuneable light emission through one-pot synthesis of polymer matrixes with embedded carbon dots assembled in situ. Importantly, different luminescence colours were produced simply by preparing C-dot/polymer films using carbon precursors that yielded C-dots exhibiting distinct fluorescence emission profiles. Furthermore, mixtures of C-dot precursors could be also employed for fabricating films exhibiting different colours. In particular, we successfully produced films emitting white light with attractive properties (i.e. ``warm'' white light with a high colour rendering index) - a highly sought after goal in optical technologies. Electronic supplementary information (ESI

  3. Pin-Hole Free Perovskite Film for Solar Cells Application Prepared by Controlled Two-Step Spin-Coating Method

    NASA Astrophysics Data System (ADS)

    Bahtiar, A.; Rahmanita, S.; Inayatie, Y. D.

    2017-05-01

    Morphology of perovskite film is a key important for achieving high performance perovskite solar cells. Perovskite films are commonly prepared by two-step spin-coating method. However, pin-holes are frequently formed in perovskite films due to incomplete conversion of lead-iodide (PbI2) into perovskite CH3NH3PbI3. Pin-holes in perovskite film cause large hysteresis in current-voltage curve of solar cells due to large series resistance between perovskite layer-hole transport material. Moreover, crystal structure and grain size of perovskite crystal are also other important parameters for achieving high performance solar cells, which are significantly affected by preparation of perovskite film. We studied the effect of preparation of perovskite film using controlled spin-coating parameters on crystal structure and morphological properties of perovskite film. We used two-step spin-coating method for preparation of perovskite film with varied spinning speed, spinning time and temperature of spin-coating process to control growth of perovskite crystal aimed to produce high quality perovskite crystal with pin-hole free and large grain size. All experiment was performed in air with high humidity (larger than 80%). The best crystal structure, pin-hole free with large grain crystal size of perovskite film was obtained from film prepared at room temperature with spinning speed 1000 rpm for 20 seconds and annealed at 100°C for 300 seconds.

  4. Preparation of conductive Cu thin film by the reaction of Cu nitrate with polymers.

    PubMed

    Yang, Sangsun; Yoon, Jae-Cheol; Yun, Jung-Yeul; Kim, Yong-Jin; Yu, Ji-Hun

    2013-09-01

    Cu nanoparticle-colloid was prepared by using electrical wire explosion process in liquid and it showed good dispersion stability without any kinds of additives. Mixed Cu nano-colloid was prepared with Cu nanoparticle-colloid, Copper (II) nitrate trihydrate, and polyvinyl pyrrolidone. Cu atoms are supplied from the dissociation reaction between Copper (II) nitrate trihydrate and polyvinyl pyrrolidone and fill up the gaps between Cu nanoparticles during the thermal sintering. Conductive (45 microOmega cm) Cu film was prepared at the sintering temperature of 200 degrees C by the enhancement of the formation of sintering necks.

  5. Comparison of Cf-252 thin-film sources prepared by evaporation or self-transfer.

    PubMed

    Algutifan, N J; Sherman, S R; Alexander, C W

    2015-02-01

    Thin-film sources containing Cf-252 were prepared by two techniques—evaporation and self-transfer—to determine whether sources prepared by simple evaporation work as well as sources prepared by self-transfer for alpha particle studies. The sources were analyzed by alpha and gamma spectroscopy. Results indicate that self-transfer sources exhibit less alpha energy straggling and alpha energy loss than evaporative sources. Fission fragments may also self-transfer, and sources made by self-transfer may need time to decay before reaching radioactive equilibrium. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Complex conductivity of polyacetylene films prepared by different methods

    NASA Astrophysics Data System (ADS)

    Ito, Kohzo; Tanabe, Yoshikazu; Akagi, Kazuo; Shirakawa, Hideki

    1992-01-01

    The frequency (f) and temperature (T) dependence of the complex conductivity σ* was measured for undoped and lightly doped films of highly stretchable polyacetylene (hs-PA) and Shirakawa polyacetylene (S-PA). When σ* and f were reduced by using the dc conductivity σ(0), all the experimental data of σ* of hs-PA were on a master curve whereas those of S-PA did not show such universality. The data analysis based on the conductivity relaxation formalism revealed that the functional form H(τ)~τα (τmin<τ<τmax, -1<α<1) of the relaxation spectrum H(τ), i.e., the distribution function of relaxation time τ, fitted the experimental data best and that α was independent of T for hs-PA while α was proportional to T for S-PA. The T-independent α for hs-PA indicates isoenergetic hopping between equivalent sites, so that the conduction mechanism in hs-PA can be ascribed to acoustic-phonon-assisted hopping of charged solitons between PA chains. On the other hand, it is likely that the inter-fibril-barrier hopping makes the main contribution to the conduction mechanism in S-PA. This difference in conduction mechanisms between hs-PA and S-PA is attributed to their morphological dissimilarities.

  7. Preparation of flexible optical waveguide film with refractive index tunability

    NASA Astrophysics Data System (ADS)

    Kwon, Yong Ku; Noh, Seung Ju; Han, Jin Young; Suk, Min Kyun; Heo, Sung Ik; Jin, Sun Jin; Ahn, Hang Hee; Ahn, Cheol Hee

    2012-09-01

    Novel organic-inorganic hybrid materials were successfully synthesized by non-hydrolytic sol-gel processing. Crack-free and thick films were produced with no remaining traces of solvents without high volume shrinkage. Adjusting the chemical composition of the materials allows the precise tailoring of the optical properties of the materials, such as optical loss, birefringence, refractive index, and thermo-optic coefficient. They can be fabricated into the step index optical waveguide structures with well-defined and reproducible refractive index differences within 0.001. The transmission performance of each waveguide channel was tested using a 10 Gbps data stream. The electrical output signal from a photodetector, connected to a wide-band oscilloscope, displays a clear 10 Gbps eye pattern. We produced a series of flexible optical waveguides from organic-inorganic hybrid materials by using soft-lithographic technique. The optical losses of the flexible waveguide arrays bent over various curvatures were measured and the transmission performance of each waveguide channel was also tested. The bending losses of a flexible waveguide array were measured and found to yield no significant loss above 2 mm diameter curvature.

  8. Preparation of layered thin film samples for angle-resolved photoemission spectroscopy

    SciTech Connect

    Harrison, S. E.; Zhou, B.; Huo, Y.; Harris, J. S.; Pushp, A.; Kellock, A. J.; Parkin, S. S. P.; Chen, Y.; Hesjedal, T.

    2014-09-22

    Materials with layered van der Waals crystal structures are exciting research topics in condensed matter physics and materials science due to outstanding physical properties associated with their strong two dimensional nature. Prominent examples include bismuth tritelluride and triselenide topological insulators (TIs), which are characterized by a bulk bandgap and pairwise counter-propagating spin-polarized electronic surface states. Angle-resolved photoemission spectroscopy (ARPES) of ex-situ grown thin film samples has been limited by the lack of suitable surface preparation techniques. We demonstrate the shortcomings of previously successful conventional surface preparation techniques when applied to ternary TI systems which are susceptible to severe oxidation. We show that in-situ cleaving is a simple and effective technique for preparation of clean surfaces on ex-situ grown thin films for high quality ARPES measurements. The method presented here is universally applicable to other layered van der Waals systems as well.

  9. Preparation of DNA and protein micro arrays on glass slides coated with an agarose film

    PubMed Central

    Afanassiev, Victor; Hanemann, Vera; Wölfl, Stefan

    2000-01-01

    A thin layered agarose film on microscope slides provides a versatile support for the preparation of arrayed molecular libraries. An activation step leading to the formation of aldehyde groups in the agarose creates reactive sites that allow covalent immobilization of molecules containing amino groups. Arrays of oligonucleotides and PCR products were prepared by tip printing. After hybridization with complementary fluorescence labeled nucleic acid probes strong fluorescence signals of sequence-specific binding to the immobilized probes were detected. The intensity of the fluorescence signals was proportional to the relative amount of immobilized oligonucleotides and to the concentration of the fluorescence labeled probe. We also used the agarose film-coated slides for the preparation of protein arrays. In combination with specific fluorescence labeled antibodies these protein arrays can be used for fluorescence linked immune assays. With this approach different protein tests can be performed in parallel in a single reaction with minimal amounts of the binding reagents. PMID:10871389

  10. Preparation and properties of films cast from mixtures of poly(vinyl alcohol) and submicron particles prepared from amylose-palmitic acid inclusion complexes.

    PubMed

    Fanta, George F; Selling, Gordon W; Felker, Frederick C; Kenar, James A

    2015-05-05

    The use of starch in polymer composites for film production has been studied for increasing biodegradability, improving film properties and reducing cost. In this study, submicron particles were prepared from amylose-sodium palmitate complexes both by rapidly cooling jet-cooked starch-palmitic acid mixtures and by acidifying solutions of starch-sodium palmitate complexes. Films were cast containing poly(vinyl alcohol) (PVOH) with up to 50% starch particles. Tensile strength decreased and Young's modulus increased with starch concentration, but percent elongations remained similar to controls regardless of preparation method or starch content. Microscopy showed particulate starch distribution in films made with rapidly cooled starch-palmitic acid particles but smooth, diffuse starch staining with acidified sodium palmitate complexes. The mild effects on tensile properties suggest that submicron starch particles prepared from amylose-palmitic acid complexes provide a useful, commercially viable approach for PVOH film modification.

  11. Bias-graded deposition and tribological properties of Ti-contained a-C gradient composite film on Ti6Al4V alloy

    NASA Astrophysics Data System (ADS)

    Cai, J. B.; Wang, X. L.; Bai, W. Q.; Zhao, X. Y.; Wang, T. Q.; Tu, J. P.

    2013-08-01

    Ti-contained a-C gradient composite film with a thickness 1.5 μm was deposited on medical Ti6Al4V alloy substrate using a closed field unbalanced magnetron sputtering with bias-graded voltage through -20 V to -150 V. The mechanical and tribological properties were evaluated from nanoindentation, scratch test and ball-on-disk tribometer. Compared with the constant-bias film deposited at -150 V, the bias-graded film has the approximate hardness (19 GPa) but high toughness and adhesion strength. At a normal load of 10 N, the bias-graded composite film shows a low friction coefficient of 0.08 and wear rate of 2.89 × 10-16 m3 N-1 m-1 in ambient air. While in Hanks’ solution, the film has the same low friction coefficient but low wear rate of 4.63 × 10-17 m3 N-1 m-1. Excellent wear resistance in Hanks’ solution may bring about a biological application for the Ti-contained a-C gradient composite film.

  12. MALDI MS sample preparation by using paraffin wax film: systematic study and application for peptide analysis.

    PubMed

    Wang, Junhua; Chen, Ruibing; Ma, Mingming; Li, Lingjun

    2008-01-15

    Recently developed sample preparation techniques employing hydrophobic sample support have improved the detection sensitivity and mass spectral quality of matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS). These methods concentrate the samples on target by minimizing the sample area via the solvent repellent effect of the target surface. In the current study, we employed the use of paraffin wax film (Parafilm M) for improved MALDI MS analysis of low-abundance peptide mixtures, including neuronal tissue releasate and protein tryptic digests. This thin film was found to strongly repel polar solvents including water, methanol, and acetonitrile, which enabled the application of a wide range of sample preparation protocols that involved the use of various organic solvents. A "nanoliter-volume deposition" technique employing a capillary column has been used to produce tiny ( approximately 400 microm) matrix spots of 2,5-dihydroxybenzoic acid on the film. By systematically optimizing the sample volume, solvent composition, and film treatment, the Parafilm M substrate in combination with the nanoliter-volume matrix deposition method allowed dilute sample to be concentrated on the film for MALDI MS analysis. Peptide mixtures with nanomolar concentrations have been detected by MALDI time-of-flight and MALDI Fourier transform ion cyclotron resonance mass spectrometers. Overall, the use of Parafilm M enabled improved sensitivity and spectral quality for the analysis of complex peptide mixtures.

  13. Preparation of nanostructured PbS thin films as sensing element for NO2 gas

    NASA Astrophysics Data System (ADS)

    Kaci, S.; Keffous, A.; Hakoum, S.; Trari, M.; Mansri, O.; Menari, H.

    2014-06-01

    In this work, we demonstrate that semiconducting films of AIVBVI compounds, in particular, of nanostructured lead sulfide (PbS) which prepared by chemical bath deposition (CBD), can be used as a sensing element for nitrogen dioxide (NO2) gas. The CBD method is versatile, simple in implementation and gives homogeneous semiconductor structures. We have prepared PbS nanocrystalline thin film at different reaction baths and temperatures. In the course of deposition, variable amounts of additives, such as organic substances among them, were introduced into the baths. The energy dispersive analysis (EDX) confirms the chemical composition of PbS films. A current-voltage (I-V) characterization of Pd/nc-PbS/a-SiC:H pSi(100)/Al Schottky diode structures were studied in the presence of NO2 gas. The gas sensing behavior showed that the synthesized PbS nanocrystalline thin films were influenced by NO2 gas at room temperature. The results can be used for developing an experimental sensing element based on chemically deposited nanostructured PbS films which can be applicable in gas sensors.

  14. Reactions of oxyfluoride precursors for the preparation of barium yttrium cuprate films

    NASA Astrophysics Data System (ADS)

    Yoshizumi, M.; Seleznev, I.; Cima, M. J.

    2004-04-01

    Precursor films prepared by metal organic deposition are shown to be much richer in fluorine than previously suspected. The ratio of fluorine to barium is 2.7 when the film is prepared at 400 °C and decreases with increasing temperature. That is, the films contain more fluorine than can be explained by only barium fluoride being present. The remaining F/Ba ratio trajectory of MOD decreases from 2.7 to about 1.5 without the formation of detectable Ba 2YCu 3O 6.5 (YBCO). The trajectory is also shown to include compositions known to contain low melting liquids. These observations show that YBCO formation from MOD-derived precursor occurs in multiple steps: (1) decomposition of YF 3, (2) decomposition of BaF 2 without YBCO nucleation, (3) formation of YBCO via liquid phase. This means small amount of oxyfluoride melt is present in the film during the conversion to YBCO. Thicker films have a larger F/Ba ratio at any given temperature which possibly leads to more melt. The melt may contribute to the densification and the epitaxial growth of YBCO. It may also, however, cause reaction with substrate and/or buffer layer.

  15. Preparation and property of UV-curable polyurethane acrylate film filled with cationic surfactant treated graphene

    NASA Astrophysics Data System (ADS)

    Xu, Jinghong; Cai, Xia; Shen, Fenglei

    2016-08-01

    The preparation of nanocomposite films composed of UV-curable polyurethane acrylate (PUA) and modified graphene were demonstrated in this paper. Cetyl trimethyl ammonium bromide modified graphene (CTAB-G) was prepared via intercalation of cationic surfactant and subsequently incorporated into PUA by UV curing technology. Fourier transform infrared spectra, wide-angle X-ray diffraction, scanning electron microscopy and transmission electron microscopy were used to characterize the structure and morphology of CTAB-G, as well as CTAB-G/PUA nanocomposite films. The results revealed that the CTAB-G sheets were layer-by-layer structure and dispersed uniformly in PUA matrix. Thermal gravimetric analysis showed that the thermal stabilities of UV-curable PUA nanocomposite films in this work were much higher than that of PUA nanocomposites previously reported. Dynamic mechanical analysis indicated that the dynamic mechanical properties of nanocomposite films were greatly enhanced in the presence of modified graphene sheets. In addition, the CTAB-G/PUA nanocomposite films exhibited improved dielectric properties and electrical conductivities compared with the pure PUA.

  16. A facile method for preparing highly conductive and reflective surface-silvered polyimide films

    NASA Astrophysics Data System (ADS)

    Liao, Yuan; Cao, Bing; Wang, Wen-Cai; Zhang, Liqun; Wu, Dezhen; Jin, Riguang

    2009-07-01

    A novel method was developed for the preparation of reflective and electrically conductive surface-silvered polyimide (PI) films. The polyimide films were functionalized with poly(dopamine), simply by dipping the PI films into aqueous dopamine solution and mildly stirring at room temperature. Electroless plating of silver was readily carried out on the poly(dopamine) deposited PI (PI-DOPA) surface. The surface compositions of the modified PI films were studied by X-ray photoelectron spectroscopy (XPS). XPS results show that the PI-DOPA surfaces were successfully deposited with ploy(dopamine) and were ready for electroless deposition of silver. The poly(dopamine) layer was used not only as the chemi-sorption sites for silver particles during the electroless plating of silver, but also as an adhesion promotion layer for the electrolessly deposited silver. The as-prepared silvered PI films show high conductivity and reflectivity, with a surface resistance of 1.5 Ω and a reflectivity of 95%, respectively.

  17. In situ preparation, electrical and surface analytical characterization of pentacene thin film transistors.

    PubMed

    Lassnig, R; Striedinger, B; Hollerer, M; Fian, A; Stadlober, B; Winkler, A

    2014-09-21

    The fabrication of organic thin film transistors with highly reproducible characteristics presents a very challenging task. We have prepared and analyzed model pentacene thin film transistors under ultra-high vacuum conditions, employing surface analytical tools and methods. Intentionally contaminating the gold contacts and SiO2 channel area with carbon through repeated adsorption, dissociation, and desorption of pentacene proved to be very advantageous in the creation of devices with stable and reproducible parameters. We mainly focused on the device properties, such as mobility and threshold voltage, as a function of film morphology and preparation temperature. At 300 K, pentacene displays Stranski-Krastanov growth, whereas at 200 K fine-grained, layer-like film growth takes place, which predominantly influences the threshold voltage. Temperature dependent mobility measurements demonstrate good agreement with the established multiple trapping and release model, which in turn indicates a predominant concentration of shallow traps in the crystal grains and at the oxide-semiconductor interface. Mobility and threshold voltage measurements as a function of coverage reveal that up to four full monolayers contribute to the overall charge transport. A significant influence on the effective mobility also stems from the access resistance at the gold contact-semiconductor interface, which is again strongly influenced by the temperature dependent, characteristic film growth mode.

  18. In situ preparation, electrical and surface analytical characterization of pentacene thin film transistors

    PubMed Central

    Lassnig, R.; Striedinger, B.; Hollerer, M.; Fian, A.; Stadlober, B.; Winkler, A.

    2015-01-01

    The fabrication of organic thin film transistors with highly reproducible characteristics presents a very challenging task. We have prepared and analyzed model pentacene thin film transistors under ultra-high vacuum conditions, employing surface analytical tools and methods. Intentionally contaminating the gold contacts and SiO2 channel area with carbon through repeated adsorption, dissociation, and desorption of pentacene proved to be very advantageous in the creation of devices with stable and reproducible parameters. We mainly focused on the device properties, such as mobility and threshold voltage, as a function of film morphology and preparation temperature. At 300 K, pentacene displays Stranski-Krastanov growth, whereas at 200 K fine-grained, layer-like film growth takes place, which predominantly influences the threshold voltage. Temperature dependent mobility measurements demonstrate good agreement with the established multiple trapping and release model, which in turn indicates a predominant concentration of shallow traps in the crystal grains and at the oxide-semiconductor interface. Mobility and threshold voltage measurements as a function of coverage reveal that up to four full monolayers contribute to the overall charge transport. A significant influence on the effective mobility also stems from the access resistance at the gold contact-semiconductor interface, which is again strongly influenced by the temperature dependent, characteristic film growth mode. PMID:25814770

  19. Preparation and characterization of thick-film Ni/MH battery.

    PubMed

    Do, Jing-Shan; Yu, Sen-Hao; Cheng, Suh-Fen

    2004-07-30

    Using the porous polypropylene (PP) films sputtered with gold and the Ni as current collectors, the electroactive materials (Ni(OH)2 and metal hydride (MH)) of positive and negative electrodes were prepared on the current collector using thick-film technology. Two types of cell configurations were prepared and the characteristics of these batteries were compared. The cycle number for the formation of batteries based on the porous PP film was found to be 2, which was significantly less than that of batteries based on the ceramic substrates. Using the porous PP film as substrate, the number of cycles for the formation of battery increased from 2 to 5 with the increase of the charge/discharge rate from 0.1C/0.025C to 2.0C/0.5C. The silver oxides dendrites formed by the oxidation of silver paste used to adhere the current collectors and the conducting wires in the charge/discharge process caused a short contact between the positive and negative electrodes, which then caused the battery failure. The cycle life of the battery based on the porous PP film was found to be greater than 400 when the charge/discharge rate was 2.0C/0.5C.

  20. Preparation and physical properties of tara gum film reinforced with cellulose nanocrystals.

    PubMed

    Ma, Qianyun; Hu, Dongying; Wang, Lijuan

    2016-05-01

    Cellulose nanocrystals (CNC) prepared from microcrystalline cellulose were blended in tara gum solution to prepare nanocomposite films. The morphology, crystallinity, and thermal properties of the CNC and films were evaluated by using transmission electron microscopy, X-ray diffractometry, and thermogravimetric analysis, respectively. The resultant CNC was rod-shaped with diameters of around 8.6 nm. The effect of CNC content on physical and thermal properties of films was studied. The composite film tensile strength increased from 27.86 to 65.73 MPa, elastic modulus increased from 160.98 MPa to 882.49 MPa and the contact angle increased from 55.8° to 98.7° with increasing CNC content from 0 to 6 wt%. However, CNC addition increased the thermal stability slightly and CNC content above 6 wt% decreased the tensile strength by CNC aggregation in the matrix. The nanocomposite film containing 6 wt% CNC possessed the highest light transmittance, mechanical properties, and lowest oxygen permeability. CNC addition is a suitable method to modify tara gum matrix polymer properties. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Film electrode prepared from oppositely charged silicate submicroparticles and carbon nanoparticles for selective dopamine sensing.

    PubMed

    Celebanska, Anna; Tomaszewska, Dorota; Lesniewski, Adam; Opallo, Marcin

    2011-07-15

    Film electrodes prepared from oppositely charged silicate submicroparticles and carbon nanoparticles was applied for selective dopamine sensing. Mesoporous silicate submicroparticles with tetraalkylammonium functionalities were prepared by sol-gel method. They were immobilised on an indium tin oxide film surface together with phenylsulphonated carbon nanoparticles by layer-by-layer method: alternative immersion into their suspensions. As it is shown by scanning electron microscopy the obtained film is composed of silicate submicroparticles covered by carbon nanoparticles. The nanoparticulate film is stable and its electroactive surface is significantly larger than substrate. Accumulation of redox active cations indicates that only fraction charged functionalities of carbon nanoparticles are employed in film formation. The obtained electrode exhibits catalytic properties towards dopamine oxidation and its interferences as ascorbic acid, uric acid and acetaminophen. This allows for selective determination of tenth micromolar concentration of dopamine in the presence of these interferences at milimolar level. The detection limit and linear range were determined to 0.1 × 10⁻⁶ mol dm⁻³ and 0.3-18 × 10⁻⁶ mol dm⁻³ respectively.

  2. Preparation of polysaccharide supramolecular films by vine-twining polymerization approach.

    PubMed

    Kadokawa, Jun-ichi; Nomura, Shintaro; Hatanaka, Daisuke; Yamamoto, Kazuya

    2013-10-15

    In this study, we investigated the preparation of polysaccharide supramolecular films through the formation of inclusion complexes by amylose in vine-twining polymerization using carboxymethyl cellulose-graft-poly(ε-caprolactone) (CMC-g-PCL) as a new guest polymer. First, hydrogels were prepared by phosphorylase-catalyzed enzymatic polymerization in the presence of CMC-g-PCL according to the vine-twining polymerization manner. The XRD result of a powdered sample obtained by lyophilization of the resulting hydrogel indicated the presence of inclusion complexes of amylose with the PCL graft-chains between intermolecular (CMC-g-PCL)s, which acted as supramolecular cross-linking points for the hydrogelation. Then, the supramolecular films were obtained by adding water to the powdered samples, followed by drying. The mechanical properties of the selected films examined by tensile testing were superior to those of a CMC film. The effect of the supramolecular cross-linking structures on the mechanical properties of the films was evaluated further by several investigations.

  3. Preparation of novel polydimethylsiloxane solid-phase microextraction film and its application in liquid sample pretreatment.

    PubMed

    Wei, Fang; Zhang, Fang-Fang; Liao, Hui; Dong, Xu-Yan; Li, Yan-Hua; Chen, Hong

    2011-02-01

    In this paper, an extraction approach based on the use of a novel polydimethylsiloxane (PDMS) film as the extraction medium was described. Two kinds of PDMS films with smooth surface and frosted surface were prepared and were practically evaluated for extraction. A model analytical problem, the determination of organochlorine pesticides in water samples, was selected for practical evaluation of the film extraction procedure by direct extraction and solvent desorption, followed by gas chromatography (GC) analysis with electron capture detection (ECD). The main variables affecting the extraction process such as the extraction time, the extraction temperature, the elution conditions, etc. were studied. The method was characterized on the basis of its linearity, precision, and limits of detection. The novel approach was sensitive and precise enough for the detection of the target analytes in the low nanogram per liter range using 5 mL of sample. In fact, limits of detection ranging from 0.77 to 10.25 ng/L were obtained. Compared with the solid-phase microextraction (SPME) fiber, the robust extraction film has a large extraction capacity, low cost of preparation. Besides, owing to the simplicity of the extraction procedures, in-site sample preparation for environmental monitor may be realized.

  4. Characterization of Si-N films prepared by reactive ion beam sputtering

    NASA Astrophysics Data System (ADS)

    Aggarwal, M. D.; Ashok, S.; Fonash, S. J.

    1982-05-01

    Application of silicon-nitride (Si-N) as a passivant in com-pound semiconductor technology requires a low-temperature deposition process to prevent dissociation of the volatile constituents of the semiconductor. With this in mind, an exploratory study of Si-N films prepared at room temperature using low-energy, reactive ion-beam sputtering has been carried out. The electrical and optical characteristics of the films have been studied, and an annealing step is found necessary to reduce the conductivity of the nitride and im-prove the interfacial properties.

  5. Preparation and Characterization Of Mg/Mn Blayer Metal Hydrides Thin Films

    NASA Astrophysics Data System (ADS)

    Jangid, M. K.; Nehra, S. P.; Singh, M.

    2011-12-01

    Bilayer Mg/Mn thin films prepared using thermal evaporation method. Annealed and annealed hydrogenated films have been characterized using UV-Vis spectroscopy, Keithley electrometer and Van der Pauw method. The optical band gap was found to be increased due to hydrogenation and decrease with annealing time. The conductivity has been found to be decreased with hydrogen and increased with annealing time. The resistivity measurements show that hydrogen interacts with Mg/Mn bilayer according to the anionic model and relative resistivity increases with hydrogen pressure, due to the net effect of hydrogen absorption with pressure.

  6. Preparation, characterization, and nonlinear optical properties of graphene oxide-carboxymethyl cellulose composite films

    NASA Astrophysics Data System (ADS)

    Wang, Jiaojiao; Feng, Miao; Zhan, Hongbing

    2014-04-01

    The preparation and characterization of free-standing films made of a graphene oxide-carboxymethyl cellulose composite material is described. Characterization was accomplished using transmission electron microscopy, ultraviolet-visible absorption spectroscopy, Raman spectroscopy, and thermal gravimetric analysis. The nonlinear optical performance of this composite material was studied using the open aperture Z-scan technique in the nanosecond regime using a 532-nm wavelength laser. Results show that the composite has nonlinear optical properties that are much enhanced when composited with graphene oxide. All phenomena indicate that the film is a potential candidate for optical limiting applications.

  7. Luminescence properties of Lu2O3: Tb film prepared by Pechini sol-gel method

    NASA Astrophysics Data System (ADS)

    Shen, Siqing; Wang, Jian; Xu, Zhibin; Xie, Jianjun; Shi, Ying

    2011-02-01

    Uniform and crack free Tb3+ doped lutetium oxide (Lu2O3:Tb) films were prepared by Pechini sol-gel method combined with the spin-coating technique. The influence of the different substrate (monocrystalline silicon (111) and silica glass) and atmosphere (N2 and Air) on the luminescence properties of films was investigated. According to the emission spectra, we found that the luminous intensity was higher on silica glass substrate. Moreover, it was found that the luminous intensity calcined in N2 was higher almost twice as that calcined in air.

  8. Luminescence properties of Lu2O3: Tb film prepared by Pechini sol-gel method

    NASA Astrophysics Data System (ADS)

    Shen, Siqing; Wang, Jian; Xu, Zhibin; Xie, Jianjun; Shi, Ying

    2010-10-01

    Uniform and crack free Tb3+ doped lutetium oxide (Lu2O3:Tb) films were prepared by Pechini sol-gel method combined with the spin-coating technique. The influence of the different substrate (monocrystalline silicon (111) and silica glass) and atmosphere (N2 and Air) on the luminescence properties of films was investigated. According to the emission spectra, we found that the luminous intensity was higher on silica glass substrate. Moreover, it was found that the luminous intensity calcined in N2 was higher almost twice as that calcined in air.

  9. Coimmobilization of urease and glutamate dehydrogenase in electrochemically prepared polypyrrole-polyvinyl sulfonate films.

    PubMed

    Gambhir, A; Gerard, M; Mulchandani, A K; Malhotra, B D

    2001-01-01

    Immobilization of urease and glutamate dehydrogenase enzymes in electrochemically prepared polypyrrole-polyvinyl sulfonate films (PPY-PVS) was carried out using physical adsorption and electrochemical entrapment techniques. Detailed studies on optimum pH, Fourier transform infrared spectroscopy, cyclic voltammetry, and scanning electron microscopy of the enzymes in the immobilized state were conducted. The value of the apparent Michaelis-Menten constant was experimentally determined to be 2.5 and 2.7 for physically adsorbed and electrochemically entrapped urease in PPY-PVS films, respectively.

  10. Preparation of Aluminum Nanomesh Thin Films from an Anodic Aluminum Oxide Template as Transparent Conductive Electrodes

    PubMed Central

    Li, Yiwen; Chen, Yulong; Qiu, Mingxia; Yu, Hongyu; Zhang, Xinhai; Sun, Xiao Wei; Chen, Rui

    2016-01-01

    We have employed anodic aluminum oxide as a template to prepare ultrathin, transparent, and conducting Al films with a unique nanomesh structure for transparent conductive electrodes. The anodic aluminum oxide template is obtained through direct anodization of a sputtered Al layer on a glass substrate, and subsequent wet etching creates the nanomesh metallic film. The optical and conductive properties are greatly influenced by experimental conditions. By tuning the anodizing time, transparent electrodes with appropriate optical transmittance and sheet resistance have been obtained. The results demonstrate that our proposed strategy can serve as a potential method to fabricate low-cost TCEs to replace conventional indium tin oxide materials. PMID:26831759

  11. Biodegradable Starch/Copolyesters Film Reinforced with Silica Nanoparticles: Preparation and Characterization

    NASA Astrophysics Data System (ADS)

    Lima, Roberta A.; Oliveira, Rene R.; Wataya, Célio H.; Moura, Esperidiana A. B.

    Biodegradable starch/copolyesters/silica nanocomposite films were prepared by melt extrusion, using a twin screw extruder machine and blown extrusion process. The influence of the silica nanoparticle addition on mechanical and thermal properties of nanocomposite films was investigated by tensile tests; X-rays diffraction (XRD), differential scanning calorimetry (DSC) and Scanning electron microscopy (SEM) analysis and the correlation between properties was discussed. The results showed that incorporation of 2 % (wt %) of SiO2 nanoparticle in the blend matrix of PBAT/Starch, resulted in a gain of mechanical properties of blend.

  12. Preparation of Aluminum Nanomesh Thin Films from an Anodic Aluminum Oxide Template as Transparent Conductive Electrodes.

    PubMed

    Li, Yiwen; Chen, Yulong; Qiu, Mingxia; Yu, Hongyu; Zhang, Xinhai; Sun, Xiao Wei; Chen, Rui

    2016-02-02

    We have employed anodic aluminum oxide as a template to prepare ultrathin, transparent, and conducting Al films with a unique nanomesh structure for transparent conductive electrodes. The anodic aluminum oxide template is obtained through direct anodization of a sputtered Al layer on a glass substrate, and subsequent wet etching creates the nanomesh metallic film. The optical and conductive properties are greatly influenced by experimental conditions. By tuning the anodizing time, transparent electrodes with appropriate optical transmittance and sheet resistance have been obtained. The results demonstrate that our proposed strategy can serve as a potential method to fabricate low-cost TCEs to replace conventional indium tin oxide materials.

  13. Preparation, characterization and antibacterial applications of ZnO-nanoparticles coated polyethylene films for food packaging.

    PubMed

    Tankhiwale, Rasika; Bajpai, S K

    2012-02-01

    The present work describes the preparation of ZnO nanoparticles loaded starch-coated polyethylene film. The presence of ZnO nanoparticles was confirmed by surface plasmon resonance (SPR), X-ray diffraction (XRD) studies and transmission electron microscopy (TEM). The ZnO loaded film was tested for its biocidal action against model bacteria Escherichia coli using zone inhibition and killing kinetics of bacterial growth methods. This newly developed material bears potential to be used as food packaging material to prevent food stuff from bacterial contamination.

  14. Preparation of high-performance optical coatings with fluoride nanoparticle films made from autoclaved sols.

    PubMed

    Murata, Tsuyoshi; Ishizawa, Hitoshi; Motoyama, Izumi; Tanaka, Akira

    2006-03-01

    An ultralow refractive index is very advantageous when one designs antireflective coatings. We successfully obtained high-quality MgF2 thin films with ultralow refractive indices from autoclaved sols prepared from magnesium acetate and hydrofluoric acid. The MgF2 films consist of nanosized particles, and they have high laser-exposure durability at 193 nm. The reflectance of the antireflective coating with five layers, of which the top layer is formed by our method, is lower than 0.6% in the incident angle range of 0 degrees - 60 degrees at 193 nm.

  15. Thickness-dependent photocatalytic performance of nanocrystalline TiO2 thin films prepared by sol-gel spin coating

    NASA Astrophysics Data System (ADS)

    Wu, Chung-Yi; Lee, Yuan-Ling; Lo, Yu-Shiu; Lin, Chen-Jui; Wu, Chien-Hou

    2013-09-01

    TiO2 nanocrystalline thin films on soda lime glass have been prepared by sol-gel spin coating. The thin films were characterized for surface morphology, crystal structure, chemical composition, thickness, and transparency by atomic force microscopy (AFM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), ellipsometry, and UV-vis spectrophotometry. The films prepared by titanium tetraisopropoxide (TTIP) as the precursor under pH of 3.5 ± 0.5 and with calcination temperature of 450 ̊C for 3 h exhibited superior homogeneous aggregation, good optical transparency, superhydrophilicity, and reliable thickness. The effect of film thickness on the photocatalytic degradation of acid yellow 17 was investigated under UV irradiation. The photocatalytic activity was strongly correlated with the number of coatings and followed Langmuir-type kinetics. Under the same film thickness, TiO2 thin films prepared by 0.1 M TTIP exhibited more efficient photocatalytic activity than those prepared by 0.3 M TTIP. For thin films prepared by 0.1 M TTIP, the maximum specific photocatalytic activity occurred at 5 coatings with thickness of 93 ± 1 nm. A model was proposed to rationalize the dependence of the film thickness on the photocatalytic activity, which predicts the existence of an optimum film thickness.

  16. Preparation and characterization of Co epitaxial thin films on Al2O3(0001) single-crystal substrates

    NASA Astrophysics Data System (ADS)

    Yabuhara, Osamu; Ohtake, Mitsuru; Nukaga, Yuri; Futamoto, Masaaki

    2011-01-01

    Co epitaxial thin films were prepared on Al2O3(0001) single-crystal substrates in a substrate temperature range between 50 and 500 °C by ultra high vacuum molecular beam epitaxy. Effects of substrate temperature on the structure and the magnetic properties of the films were investigated. The films grown at temperatures lower than 150 °C consist of fcc- Co(111) crystal. With increasing the substrate temperature, hcp-Co(0001) crystal coexists with the fcc crystal and the volume ratio of hcp to fcc crystal increases. The films prepared at temperatures higher than 250 °C consist primarily of hcp crystal. The film growth seems to follow island-growth mode. The films consisting primarily of hcp crystal show perpendicular magnetic anisotropy. The domain structure and the magnetization properties are influenced by the magnetocrystalline anisotropy and the shape anisotropy caused by the film surface roughness.

  17. Preparation of transparent self-standing thin films made from acetylated euglenoid β-1,3-glucans.

    PubMed

    Shibakami, Motonari; Tsubouchi, Gen; Sohma, Mitsugu; Hayashi, Masahiro

    2015-11-20

    The feasibility of using acetylparamylon to prepare self-standing optical films was investigated. Its thermal stability, represented by the glass transition temperature, and 5% weight loss temperature are equivalent to those of acetylcellulose. The mechanical properties (maximum stress, elongation at break, and elastic modulus) of acetylparamylon films prepared by solution casting were comparable to those of acetylcellulose films. The degrees of their transparency and birefringence were the same as those of the acetylcellulose film. These results, together with the finding that acetylparamylon with a higher degree of acetylation formed a thin film with fewer micrometer-sized defects and that acetylparamylon with a lower degree of acetylation formed a thin film with a nanometer-level flat surface, suggest that acetylparamylon is a feasible material for self-standing optical film. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. New process for preparing complex-shaped dielectric film similar to Mylar. [Polyethylene terephthalate

    SciTech Connect

    Lagasse, R.R.; Kraynik, A.M.

    1982-02-01

    A new thermoforming/heat-treatment process yields complex-shaped dielectric film having electrical and shrinkage properties similar to those of flat Mylar film. This similarity should extend to other physical properties because the new process is directly analogous to the process used to prepare Mylar. Commercially available poly(ethylene terephthalate) film is formed into a cavity at approx. 110/sup 0/C and then heat treated at approx. 180/sup 0/C. A laboratory-scale forming apparatus has produced cylindrically shaped films having depth/diameter ratio approx. 1, a tapered wall-section, and variation in wall thickness of < 3X. Evaluation of other forming methods suggests that the production rate and thickness uniformity can be improved with existing technology. Thermal shrinkage at 150/sup 0/C, 1 kHz dielectric constant from -55 to +70/sup 0/C, leakage current at 1 kV, and breakdown voltage have been measured for both the complex-shaped film and Mylar. These comparative measurements indicate that the complex-shaped film could replace the flat Mylar dielectric currently used in energy-storage capacitors. A complex-shaped energy-storage capacitor could enhance safety in certain nuclear weapon applications by allowing strong-link devices in a firing set to be enclosed by a weak link.

  19. Characterization and Electrochromic Properties of Vanadium Oxide Thin Films Prepared via Spray Pyrolysis

    NASA Astrophysics Data System (ADS)

    Mousavi, M.; Kompany, A.; Shahtahmasebi, N.; Bagheri-Mohagheghi, M.-M.

    2013-08-01

    Vanadium oxide thin films were grown on glass substrates using spray pyrolysis technique. The effects of substrate temperature, vanadium concentration in the initial solution and the solution spray rate on the nanostructural and the electrochromic properties of deposited films are investigated. Characterization and the electrochromic measurements were carried out using X-ray diffraction, scanning electron microscopy and cyclic voltammogram. XRD patterns showed that the prepared films have polycrystalline structure and are mostly mixed phases of orthorhombic α-V2O5 along with minor β-V2O5 and V4O9 tetragonal structures. The preferred orientation of the deposited films was found to be along [101] plane. The cyclic voltammogram results obtained for different samples showed that only the films with 0.2 M solution concentration, 5 ml/min solution spray rate and 450°C substrate temperature exhibit two-step electrochromic properties. The results show a correlation between cycle voltammogram, morphology and resistance of the films.

  20. Characterizations of maghemite thin films prepared by a sol-gel method

    SciTech Connect

    Lau, L. N. Ibrahim, N. B.

    2015-09-25

    Iron is one of the abundant elements of Mother Nature and its compound, iron oxide is an interesting material to study since its discovery in the form of magnetite. It can exist in many phases such as hematite and maghemite, this unique nature has put it as a potential candidate in various applications. The aim of this work is to study the influence of different precursor concentrations on the microstructural and magnetic properties of iron oxide thin film. All samples were prepared via the sol-gel method followed by a spin coating technique on quartz substrates. Iron oxide films were confirmed as maghemite phase from X-ray diffraction patterns. The film morphology was examined by a field emission scanning electron microscope and it showed non-systematic value of average grain size and film thickness throughout the study. Hysteresis loop further confirmed that maghemite is a magnetic material when it was characterized by a vibrating sample magnetometer. The coercivity did not show any correlation with molarity. Nevertheless, it increased as the precursor concentration of the film increased due to the domain behaviour. In conclusion, maghemite thin films were successfully synthesized by the sol-gel method with different precursor concentrations in this work.

  1. Porous structures of polymer films prepared by spin coating with mixed solvents under humid condition.

    PubMed

    Park, Min Soo; Joo, Wonchul; Kim, Jin Kon

    2006-05-09

    We investigate the effects of interfacial energy between water and solvent as well as polymer concentration on the formation of porous structures of polymer films prepared by spin coating of cellulose acetate butyrate (CAB) in mixed solvent of tetrahydrofuran (THF) and chloroform under humid condition. The interfacial energy between water and the solvent was gradually changed by the addition of chloroform to the solvent. At a high polymer concentration (0.15 g/cm3 in THF), porous structures were limited only at the top surfaces of CAB films, regardless of interfacial energies, due to the high viscosity of the solution. At a medium concentration (approximately 0.08 g/cm3 in THF), CAB film had relatively uniform pores at the top surface and very small pores inside the film because of the mixing of the water droplets with THF solution. When chloroform was added to THF, pores at the inner CAB film had a comparable size with those at the top surface because of the reduced degree of the mixing between the water droplets and the mixed solvent. A further decrease in polymer concentration (0.05 g/cm3 in THF) caused the final films to have a two-layer porous structure, and the size of pores at each layer was almost the same.

  2. Preparation and characterization of LiCoO2 thin films by laser ablation deposition

    NASA Astrophysics Data System (ADS)

    Antaya, M.; Dahn, J. R.; Preston, J. S.; Rossen, E.; Reimers, J. N.

    1993-03-01

    Thin films of LiCoO2 are obtained by laser ablation from sintered LiCoO2 targets. The films were deposited on stainless steel or tantalum foil substrates so they could be used as cathodes in rechargeable thin-film lithium batteries. The films are amorphous when deposited on unheated substrates but crystallize readily when heated in air above 500 C. Using X-ray diffraction, we show that the films are basically stoichiometric and have no impurity phases present. They consist partly of the normal bulk LiCoO2 phase which can be prepared by reacting Li2CO3 and CoCO3 at 850 C. However, the films also contain some of the new, low temperature LiCoO2 phase. We have synthesized bulk low temperature LiCoO2 from LiNO3 and CO(NO3)2 at 400 C to measure its structure and electrochemical properties. Electrochemical measurements can distinguish between the high and low temperature phases.

  3. Preparation of superhydrophobic poly(methyl methacrylate)-silicon dioxide nanocomposite films

    NASA Astrophysics Data System (ADS)

    Wang, Jinyan; Chen, Xinhua; Kang, Yingke; Yang, Guangbin; Yu, Laigui; Zhang, Pingyu

    2010-12-01

    Superhydrophobic poly(methyl methacrylate)-SiO 2 (coded as PMMA-SiO 2) nanocomposite films with micro-nanohierarchical structure were prepared via a simple approach in the absence of low surface-energy compounds. By spin-coating the suspension of hydrophobic silica (SiO 2) nanoparticles dispersed in PMMA solution, target nanocomposite films were obtained on glass slides. The wetting behavior of PMMA-SiO 2 nanocomposite films was investigated in relation to the dosage of SiO 2 nanoparticles dispersed in PMMA solution. It was found that hydrophilic PMMA film was transferred to superhydrophobic PMMA-SiO 2 nanocomposite films when hydrophobic SiO 2 nanoparticles were introduced into the PMMA solution at a high enough dosage (0.2 g and above). Resultant PMMA-SiO 2 nanocomposite films had a static water contact angle of above 162°, showing promising applications in selfcleaning and waterproof for outer wall of building, outer covering for automobile, sanitary wares, and so forth.

  4. [Preparation and characterization of poly-Si films on different topography substrates by AIC].

    PubMed

    Wang, Cheng-Long; Fan, Duo-Wang; Liu, Hong-Zhong; Zhang, Fu-Jia; Xing, Da; Liu, Song-Hao

    2009-03-01

    Polycrystalline silicon (poly-Si) thin-films were made on planar and textured glass substrates by aluminum-induced crystallization (AIC) of in situ amorphous silicon (a-Si) deposited by DC-magnetron. The poly-Si films were characterized by Raman spectroscopy, X-ray diffraction (XRD) and atomic force microscopy (AFM). A narrow and symmetrical Ranman peak at the wave number of about 521 cm(-1) was observed for all samples, indicating that the films were fully crystallized. XRD results show that the crystallites in the authors' AIC poly-Si films were preferably (111) oriented. The measurement of full width at half maximum (FWHW) of (111) XRD peaks showed that the quality of the films was affected by the a-Si deposition temperature and the surface morphology of the glass substrates. It is likely that an a-Si deposition temperature of 200 degrees C seems to be ideal for the preparation of poly-Si films by AIC.

  5. Universal biomimetic preparation and immobilization of layered double hydroxide films and adsorption behavior

    NASA Astrophysics Data System (ADS)

    Zhou, Wei; Zhang, Wenpeng; Chen, Zilin

    2017-01-01

    Preparation and immobilization of layered double hydroxides (LDHs) film onto multiple substrates is important and challenging in functional materials fields by date. In this work, a simple and universal polydopamine (PD)-based layer-by-layer assembly strategy was developed for the immobilization of LDHs film onto surfaces such as polypropylene chip, glass slides and metal coins. The surface of substrates was firstly modified by polydopamine functionalization, and then LDHs film was synthesized via urea method and directly immobilized on the PD layer by in situ growing strategy in one step. The PD layer as well as the final LDHs film was characterized by energy dispersive X-ray spectroscopy, scanning electron microscope, infrared spectroscopy, X-ray diffraction pattern and X-ray photoelectron spectra. It has been demonstrated the formation of the dense and homogeneous nanoscaled LDHs film with 400 nm thickness. Adsorption behavior of the fabricated NiAl-LDHs film toward anionic dyes and pharmaceuticals was further assessed. To demonstrate their extensive application, fast and high efficient adsorption of anionic dyes and pharmaceuticals was achieved by NiAl-LDHs-modified polypropylene centrifugal tube.

  6. Optical Properties of Cu-Doped ZnO Films Prepared by Cu Solution Coating.

    PubMed

    Allabergenov, Bunyod; Chung, Seok-Hwan; Kim, Sungjin; Choi, Byeongdae

    2015-10-01

    This work demonstrates the fabrication of Cu-doped ZnO films by Cu solution coating method. Cu ink was spin coated on ZnO thin films prepared by e-beam deposition. After curing and annealing at high temperatures, structural, morphological and optical properties of the films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and spectrofluorometer, respectively. The XRD results showed that ZnO films formed polycrystalline with a hexagonal wurtzite structure, and the grain size increased with increasing the annealing temperature from 500 to 850 °C. The changes in lattice parameters were caused by grain size, strain, and residual stress. Morphological analysis have revealed that the Cu-doped ZnO film after annealing at 500 °C has flat surface with uniformly distributed grain size, which became porous after higher temperature annealing process. Energy dispersive spectroscopy (EDS) and photoluminescence spectras have shown the presence of Zn, Cu, and O elements, and combined violet, blue, green and weak red emissions between 350 and 650 nm in the ZnO films, respectively.

  7. Preparation, Structural and Dielectric Properties of Solution Grown Polyvinyl Alcohol(PVA) Film

    NASA Astrophysics Data System (ADS)

    Nangia, Rakhi; Shukla, Neeraj K.; Sharma, Ambika

    2017-08-01

    Flexible dielectrics with high permittivity have been investigated extensively due to their applications in electronic industry. In this work, structural and electrical characteristics of polymer based film have been analysed. Poly vinyl alcohol (PVA) film was prepared by solution casting method. X-ray diffraction (XRD) characterization technique is used to investigate the structural properties. The semi-crystalline nature has been determined by the analysis of the obtained XRD pattern. Electrical properties of the synthesized film have been analysed from the C-V and I-V curves obtained at various frequencies and temperatures. Low conductivity values confirm the insulating behaviour of the film. However, it is found that conductivity increases with temperature. Also, the dielectric permittivity is found to be higher at lower frequencies and higher temperatures, that proves PVA to be an excellent dielectric material which can be used in interface electronics. Dielectric behaviour of the film has been explained based on dipole orientations to slow and fast varying electric field. However further engineering can be done to modulate the structural, electrical properties of the film.

  8. Growth and Characterization of CIS Thin Films Prepared by Ion Beam Sputtering Deposition

    NASA Astrophysics Data System (ADS)

    Fan, Ping; Liang, Guang-Xing; Zheng, Zhuang-Hao; Cai, Xing-Min; Zhang, Dong-Ping

    2010-04-01

    Copper indium diselenide (CuInSe2) thin films were prepared by ion beam sputtering Cu, In and Se targets continuously on BK7 glass substrates and the three-layer film was then annealed in the same vacuum chamber. X-ray diffraction shows that the CuInSe2 thin films have a single chalcopyrite structure with preferential (112) orientation. Scanning electron microscopy reveals that the CIS thin films consist of uniform and densely packed grain clusters. Energy dispersive x-ray spectroscopy demonstrates that the elemental composition of CIS films approaches the stochiometric composition ratios of 1:1:2. Raman measurement shows that the main peak is at about 174 cm-1 and this peak is identified as the A1 vibrational mode from chalcopyrite ordered CuInSe2. Optical transmission and absorption spectroscopy measurement reveal an energy band gap of about 1.05eV and an absorption coefficient of 105 cm-1. The film resistivity is about 0.01 Ωcm.

  9. Annealing effect for SnS thin films prepared by high-vacuum evaporation

    SciTech Connect

    Revathi, Naidu Bereznev, Sergei; Loorits, Mihkel; Raudoja, Jaan; Lehner, Julia; Gurevits, Jelena; Traksmaa, Rainer; Mikli, Valdek; Mellikov, Enn; Volobujeva, Olga

    2014-11-01

    Thin films of SnS are deposited onto molybdenum-coated soda lime glass substrates using the high-vacuum evaporation technique at a substrate temperature of 300 °C. The as-deposited SnS layers are then annealed in three different media: (1) H{sub 2}S, (2) argon, and (3) vacuum, for different periods and temperatures to study the changes in the microstructural properties of the layers and to prepare single-phase SnS photoabsorber films. It is found that annealing the layers in H{sub 2}S at 400 °C changes the stoichiometry of the as-deposited SnS films and leads to the formation of a dominant SnS{sub 2} phase. Annealing in an argon atmosphere for 1 h, however, causes no deviations in the composition of the SnS films, though the surface morphology of the annealed SnS layers changes significantly as a result of a 2 h annealing process. The crystalline structure, surface morphology, and photosensitivity of the as-deposited SnS films improves significantly as the result of annealing in vacuum, and the vacuum-annealed films are found to exhibit promising properties for fabricating complete solar cells based on these single-phase SnS photoabsorber layers.

  10. Highly resistive Mn-Zn ferrite films prepared from aqueous solution for GHz conducted noise suppressors

    NASA Astrophysics Data System (ADS)

    Matsushita, Nobuhiro; Abe, Tatsunobu; Kondo, Koichi; Yoshida, Shigeyoshi; Abe, Masanori

    2005-05-01

    We have prepared Mn-Zn ferrite films (MnxZnyFezO4.00-δ: 0.23film resistivity ρ increased as the amount of Fe content z decreased and very high surface resistance R>108Ω/sq was attained for the film having z<2.6. The deposited Mn-Zn ferrite films had a large saturation magnetization Ms=380-460emu/cm3 and relatively low coercivity Hc=11-29Oe. The Mn-Zn ferrite films contacted to a microstrip line (50Ω) exhibited very large transmission loss ΔPloss per thickness t, ΔPloss/t, of about 10 times larger than that of commercialized composite sheet. They exhibited sufficiently low reflection coefficient S11<-10dB. These films were applicable as noise current suppressors deposited on an interlayer of multilayer printed circuit boards.

  11. A study on various fabrication routes for preparing multilayered cubic boron nitride films and sp(3)-like boron nitride films

    NASA Astrophysics Data System (ADS)

    Wong, Sing Fai

    Cubic boron nitride (cBN) has a sp3-bonded structure which leads to excellent mechanical properties. Though cBN-rich films have been successfully fabricated by many techniques, the adhesion of the films is still unsatisfactory due to the high stresses. The maximum sustainable thickness of cBN-rich films with good adhesion is widely reported to be around 200 nm, so many practical applications of cBN coatings are hindered. In this study, we designed a series of deposition schemes in a logical sequence, in order to explore whether stress can be released, or other structural forms of BN with potential applications can be made, and to gain more fundamental understanding on the growth mechanisms of various phases observed in the films. Various fabrication processes were employed according to the following sequence: (1) A single-step process. It was showed that the maximum tolerable thickness of the cBN-rich films prepared by our system (183nm) was compatible with the result in literatures (200nm). (2) A multilayered deposition process. A thick sp2-bonded boron nitride (sP2-BN) buffer layer which was relatively deformable was added, and hence some stresses were released so as to allow a 643nm-thick, 87vol.% cBN-rich layer with acceptable adhesion to grow on top. (3) An advanced multilayer process with subsequent annealing process. A zirconium layer was pre-deposited to remove the soft buffer layer after postannealing. The interface could be strengthened as the zirconium-boride/nitride was formed. (4) Ion assist deposition at unheated condition. Composite BN films containing sp3 nanoclusters embedded in a sp2-BN matrix were fabricated. The IR technique was not sensitive enough to detect spa nanoclusters, but their presence was verified by the results of other measurements. In particular, the sp3 content can be over 30vo1.%, with a hardness 20GPa. The influences of the assist beam energy and substrate temperature on the generation of the sp3 nanoclusters were investigated

  12. Surface modification of bioactive glasses and preparation of PDLLA/bioactive glass composite films.

    PubMed

    Gao, Yuan; Chang, Jiang

    2009-08-01

    In order to improve the homogeneous dispersion of particles in the polymeric matrix, 45S5, mesoporous 58S, and 58S bioactive glasses were surface modified by esterification reactions with dodecyl alcohol at reflux temperature of 260 degrees C (named as m-45S5, m-mesoporous 58S, and m-58S, respectively). The modified particles showed better hydrophobicity and longer time of suspension in organic matrix. The PDLLA/bioactive glass composite films were fabricated using surface modified bioactive glass particles through solvent casting-evaporation method. Surface morphology, mechanical property, and bioactivity were investigated. The results revealed that the inorganic particle distribution and tensile strength of the composite films with modified bioactive glass particles were significantly improved while great bioactive properties were maintained. Scanning electron microscopy (SEM) observation illustrated that the modified bioactive glass particles were homogeneously dispersed in the PDLLA matrix. The maximum tensile strengths of composite films with modified bioactive glass particles were higher than that of composite films with unmodified bioactive glass particles. The bioactivity of the composite films were evaluated by being soaked in the simulated body fluid (SBF) and the SEM observation of the films suggested that the modified composite films were still bioactive in that they could induce the formation of HAp on its surface and the distribution of HAp was even more homogeneous on the film. The results mentioned above indicated that the surface modification of bioactive glasses with dodecyl alcohol was an effective method to prepare PDLLA/bioactive glass composites with enhanced properties. By studying the comparisons of modification effects among the three types of bioactive glasses, we could get the conclusion that the size and morphology of the inorganic particles would greatly affect the modification effects and the properties of composites.

  13. Identification of the Chemical Bonding Prompting Adhesion of a-C:H Thin Films on Ferrous Alloy Intermediated by a SiCx:H Buffer Layer.

    PubMed

    Cemin, F; Bim, L T; Leidens, L M; Morales, M; Baumvol, I J R; Alvarez, F; Figueroa, C A

    2015-07-29

    Amorphous carbon (a-C) and several related materials (DLCs) may have ultralow friction coefficients that can be used for saving-energy applications. However, poor chemical bonding of a-C/DLC films on metallic alloys is expected, due to the stability of carbon-carbon bonds. Silicon-based intermediate layers are employed to enhance the adherence of a-C:H films on ferrous alloys, although the role of such buffer layers is not yet fully understood in chemical terms. The chemical bonding of a-C:H thin films on ferrous alloy intermediated by a nanometric SiCx:H buffer layer was analyzed by X-ray photoelectron spectroscopy (XPS). The chemical profile was inspected by glow discharge optical emission spectroscopy (GDOES), and the chemical structure was evaluated by Raman and Fourier transform infrared spectroscopy techniques. The nature of adhesion is discussed by analyzing the chemical bonding at the interfaces of the a-C:H/SiCx:H/ferrous alloy sandwich structure. The adhesion phenomenon is ascribed to specifically chemical bonding character at the buffer layer. Whereas carbon-carbon (C-C) and carbon-silicon (C-Si) bonds are formed at the outermost interface, the innermost interface is constituted mainly by silicon-iron (Si-Fe) bonds. The oxygen presence degrades the adhesion up to totally delaminate the a-C:H thin films. The SiCx:H deposition temperature determines the type of chemical bonding and the amount of oxygen contained in the buffer layer.

  14. Preparation and activation of micro-arc oxidation films on a TLM titanium alloy.

    PubMed

    Yu, S; Yu, Z T

    2008-12-01

    In order to improve the biocompatibility and surface activity of a TLM alloy, a layer of a porous TiO(2) film was prepared by the micro-arc oxidation method on the surface, and then the NH(-)(2) active group was introduced on the film by an activation treatment in an aminated solution. The phase identification and surface characteristics of the micro-arc oxidation films were characterized by XRD, XPS, SEM and EDS. The in vitro blood compatibility of the TLM alloy samples with and without surface modification was evaluated by contact angle tests, hemolysis tests and electrochemical tests. The results indicate that the biocompatibility and surface activity of the TLM alloy could be remarkably improved by surface modification of micro-arc oxidation and activation treatment.

  15. Iron Oxide Films Prepared by Rapid Thermal Processing for Solar Energy Conversion

    NASA Astrophysics Data System (ADS)

    Wickman, B.; Bastos Fanta, A.; Burrows, A.; Hellman, A.; Wagner, J. B.; Iandolo, B.

    2017-01-01

    Hematite is a promising and extensively investigated material for various photoelectrochemical (PEC) processes for energy conversion and storage, in particular for oxidation reactions. Thermal treatments during synthesis of hematite are found to affect the performance of hematite electrodes considerably. Herein, we present hematite thin films fabricated via one-step oxidation of Fe by rapid thermal processing (RTP). In particular, we investigate the effect of oxidation temperature on the PEC properties of hematite. Films prepared at 750 °C show the highest activity towards water oxidation. These films show the largest average grain size and the highest charge carrier density, as determined from electron microscopy and impedance spectroscopy analysis. We believe that the fast processing enabled by RTP makes this technique a preferred method for investigation of novel materials and architectures, potentially also on nanostructured electrodes, where retaining high surface area is crucial to maximize performance.

  16. Iron Oxide Films Prepared by Rapid Thermal Processing for Solar Energy Conversion

    PubMed Central

    Wickman, B.; Bastos Fanta, A.; Burrows, A.; Hellman, A.; Wagner, J. B.; Iandolo, B.

    2017-01-01

    Hematite is a promising and extensively investigated material for various photoelectrochemical (PEC) processes for energy conversion and storage, in particular for oxidation reactions. Thermal treatments during synthesis of hematite are found to affect the performance of hematite electrodes considerably. Herein, we present hematite thin films fabricated via one-step oxidation of Fe by rapid thermal processing (RTP). In particular, we investigate the effect of oxidation temperature on the PEC properties of hematite. Films prepared at 750 °C show the highest activity towards water oxidation. These films show the largest average grain size and the highest charge carrier density, as determined from electron microscopy and impedance spectroscopy analysis. We believe that the fast processing enabled by RTP makes this technique a preferred method for investigation of novel materials and architectures, potentially also on nanostructured electrodes, where retaining high surface area is crucial to maximize performance. PMID:28091573

  17. The preparation and characterization of CN x film with high nitrogen content by cathode electrodeposition

    NASA Astrophysics Data System (ADS)

    Zhang, Jia-Tao; Cao, Chuan-Bao; Lv, Qiang; Li, Chao; Zhu, He-Sun

    2003-05-01

    CN x thin film with high nitrogen content was prepared on ITO conductive glass substrates by cathode electrodeposition, using dicyandiamide (C 2H 4N 4) in acetone as precursors. The surface morphologies, atomic bonding state, and chemical composition were analyzed by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FT-IR) spectroscopy. The CN x particles got nanometer level with the average size of 80 nm. The maximum value of the N/C atomic ratio was more than 1. Carbon and nitrogen existed mainly in the form of tetrahedral CN bonds, with a few CN bonds. From UV-Vis absorption spectrum, we found that during near-ultraviolet area the deposited CN x films appeared nonlinear optical absorption phenomena, and the ultraviolet light (200-280 nm) could be transmitted. The electrical resistivities of the films were in the range of 10 12-10 16 Ω cm.

  18. High quality thin films of thermoelectric misfit cobalt oxides prepared by a chemical solution method

    PubMed Central

    Rivas-Murias, Beatriz; Manuel Vila-Fungueiriño, José; Rivadulla, Francisco

    2015-01-01

    Misfit cobaltates ([Bi/Ba/Sr/Ca/CoO]nRS[CoO2]q) constitute the most promising family of thermoelectric oxides for high temperature energy harvesting. However, their complex structure and chemical composition makes extremely challenging their deposition by high-vacuum physical techniques. Therefore, many of them have not been prepared as thin films until now. Here we report the synthesis of high-quality epitaxial thin films of the most representative members of this family of compounds by a water-based chemical solution deposition method. The films show an exceptional crystalline quality, with an electrical conductivity and thermopower comparable to single crystals. These properties are linked to the epitaxial matching of the rock-salt layers of the structure to the substrate, producing clean interfaces free of amorphous phases. This is an important step forward for the integration of these materials with complementary n-type thermoelectric oxides in multilayer nanostructures. PMID:26153533

  19. Preparation of hierarchically aligned carbon nanotube films using the Langmuir-Blodgett technique.

    PubMed

    Lee, Jae-Hyeok; Kang, Won-Seok; Nam, Gwang-Hyeon; Choi, Sung-Wook; Kim, Jae-Ho

    2009-12-01

    Hierarchically-aligned single-walled carbon nanotube (SWNT) films over large areas were fabricated by using Langmuir-Blodgett (LB) technique. Thiophenyl-modified SWNTs spreading solution in chloroform was prepared through amidation reaction of oxidized SWNTs. The resulting SWNTs were found to form stable colloidal suspensions in organic solvents, such as chloroform, which is a suitable solvent for the LB application. The compression of the thiophenyl-modified SWNTs spread onto the water surface of an LB trough leading to a uniform SWNT Langmuir monolayer, where SWNTs were aligned parallel to the trough barrier. Optical anisotropy of SWNTs LB films on quartz substrate was confirmed by polarized UV-Vis/NIR spectroscopic measurement. Moreover, the electrical conductivity of the resulting SWNT films, which were parallel to the tube axis, was found to be approximately 15 times higher than those that were perpendicular to the axis, reflecting anisotropic electrical properties due to the uniaxial alignment of individual SWNT bundles.

  20. Synthesis and characterization of SnO2 thin films prepared by dip-coating method

    NASA Astrophysics Data System (ADS)

    Carvalho, D. H. Q.; Schiavon, M. A.; Raposo, M. T.; de Paiva, R.; Alves, J. L. A.; Paniago, Roberto. M.; Speziali, N. L.; Ferlauto, A. S.; Ardisson, J. D.

    The optical, electrical and structural properties of SnOare responsible for a large number of technological 2 applications such as gas sensors, optical-electonic devices, varistors and displays. In this paper, we report the preparation of SnO thin films deposited on glass, quartz and silicon substrates by the technique of sol-gel dip-2coating. The films were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), ellipsometry and Mössbauer spectroscopy. We combine the experimental results with ab initio all-electrons calculations, using the density functional theory within the framework of the full-potential linear augmented plane waves method, in order to extract hyperfine parameters. The results show that the synthesis method is able to produce good quality films and that the theory can be helpful to determine quantities difficult to be measured experimentally.

  1. Structural and optical properties of tin selenide thin films prepared by chemical bath deposition method

    NASA Astrophysics Data System (ADS)

    Solanki, V. R.; Parmar, R. J.; Pathak, R. J.; Parmar, M. D.

    2017-05-01

    Tin selenide (SnSe) is an important IV-VI semiconductor used for various devices like memory switching, photoelectrical cells, holographic recording systems. Chemical bath deposition technique has been used to synthesize tin selenide (SnSe) thin films. The SnSe thin films are deposited on glass substrates in an aqueous alkaline medium using sodium selenosulphate as Se-2 ion source and Tin Chloride as Sn+2 ion source. The SnSe Thin films were characterized to study the structural properties. XRD study confirms the formation of orthorhombic structural. The Prepared samples were investigated for optical characterization by UV-VIS Spectroscopy. The optical band gap was found to be direct, that is equal to 1.73eV.

  2. Faraday effect of polycrystalline bismuth iron garnet thin film prepared by mist chemical vapor deposition method

    NASA Astrophysics Data System (ADS)

    Yao, Situ; Kamakura, Ryosuke; Murai, Shunsuke; Fujita, Koji; Tanaka, Katsuhisa

    2017-01-01

    We have synthesized polycrystalline thin film composed of a single phase of metastable bismuth iron garnet, Bi3Fe5O12, on a fused silica substrate, one of the most widely utilized substrates in the solid-state electronics, by using mist chemical vapor deposition (mist CVD) method. The phase purity and stoichiometry are confirmed by X-ray diffraction and Rutherford backscattering spectrometry. The resultant thin film shows a small surface roughness of 3.251 nm. The saturation magnetization at room temperature is 1200 G, and the Faraday rotation angle at 633 nm reaches -5.2 deg/μm. Both the magnetization and the Faraday rotation angles are somewhat higher than those of polycrystalline BIG thin films prepared by other methods.

  3. Preparation of nano cellulose fibers and its application in kappa-carrageenan based film.

    PubMed

    Savadekar, N R; Karande, V S; Vigneshwaran, N; Bharimalla, A K; Mhaske, S T

    2012-12-01

    Bio-based nanocomposite films were successfully developed using nanofibrillated cellulose (NFC) as the reinforcing phase and kappa-carrageenan (KCRG) as the matrix. NFC was successfully synthesis from short stable cotton fibers by chemo-mechanical process. The bionanocomposites were prepared by incorporating 0.1, 0.2, 0.3, 0.4, 0.5, and 1wt% of the NFC into a KCRG matrix using a solution casting method there characterization was done in terms of thermal properties (DSC), morphology (SEM), water vapor transmission rate (WVTR), oxygen transmission rate (OTR), X-ray diffractograms (XRD), and tensile properties. The main conclusion arising from the analysis of the result is that the bionanocomposites containing 0.4wt% of NFC exhibited the highest enhancement in tensile strength it is almost 44% improvement. WVTR and OTR results showed improvement of all nanocomposite film compare to control KCRG film.

  4. High quality thin films of thermoelectric misfit cobalt oxides prepared by a chemical solution method

    NASA Astrophysics Data System (ADS)

    Rivas-Murias, Beatriz; Manuel Vila-Fungueiriño, José; Rivadulla, Francisco

    2015-07-01

    Misfit cobaltates ([Bi/Ba/Sr/Ca/CoO]nRS[CoO2]q) constitute the most promising family of thermoelectric oxides for high temperature energy harvesting. However, their complex structure and chemical composition makes extremely challenging their deposition by high-vacuum physical techniques. Therefore, many of them have not been prepared as thin films until now. Here we report the synthesis of high-quality epitaxial thin films of the most representative members of this family of compounds by a water-based chemical solution deposition method. The films show an exceptional crystalline quality, with an electrical conductivity and thermopower comparable to single crystals. These properties are linked to the epitaxial matching of the rock-salt layers of the structure to the substrate, producing clean interfaces free of amorphous phases. This is an important step forward for the integration of these materials with complementary n-type thermoelectric oxides in multilayer nanostructures.

  5. Nanocrystalline Janus films of inorganic materials prepared at the liquid-liquid interface.

    PubMed

    Biswas, Kanishka; Rao, C N R

    2009-05-01

    The interface between toluene and water has been employed to prepare ultrathin Janus nanocrystalline films of metal oxides, metal chalcogenides and gold, wherein the surface on the organic-side is hydrophobic and the aqueous-side is hydrophilic. We have changed the nature of the metal precursor or capping agent in the organic layer to increase the hydrophobicity. The strategy employed for this purpose is to increase the length of the alkane chain in the precursor or use a perfluroalkane derivative as precursor or as a capping agent. The hydrophobicity and hydrophilicity of the Janus films have been determined by contact angle measurements. The morphology of hydrophobic and hydrophilic sides of the film have been examined by field emission scanning electron microscopy.

  6. Preparation and activation of micro-arc oxidation films on a TLM titanium alloy

    NASA Astrophysics Data System (ADS)

    Yu, S.; Yu, Z. T.

    2008-12-01

    In order to improve the biocompatibility and surface activity of a TLM alloy, a layer of a porous TiO2 film was prepared by the micro-arc oxidation method on the surface, and then the NH-2 active group was introduced on the film by an activation treatment in an aminated solution. The phase identification and surface characteristics of the micro-arc oxidation films were characterized by XRD, XPS, SEM and EDS. The in vitro blood compatibility of the TLM alloy samples with and without surface modification was evaluated by contact angle tests, hemolysis tests and electrochemical tests. The results indicate that the biocompatibility and surface activity of the TLM alloy could be remarkably improved by surface modification of micro-arc oxidation and activation treatment.

  7. Studies on the Controlling of the Microstructural and Morphological Properties of Al Doped ZnO Thin Films Prepared by Hydrothermal Method

    NASA Astrophysics Data System (ADS)

    Gil Gang, Myeng; Shin, Seung Wook; Gurav, K. V.; Wang, YinBo; Agawane, G. L.; Lee, Jeong Yong; Moon, Jong-Ha; Hyeok Kim, Jin

    2013-10-01

    Al doped ZnO (AZO) thin films were prepared on ZnO coated glass substrates by hydrothermal synthesis technique using aqueous solutions containing zinc nitrate hexahydrate, ammonium hydroxide, and different sodium citrate concentrations at 60 °C for 6 h. The effects of different trisodium citrate concentrations on the microstructural, crystallinity, morphological, optical, and chemical properties of thin films were investigated. X-ray diffraction studies showed that the AZO thin films were grown as a polycrystalline wurtzite hexagonal phase with a c-axis preferred orientation and without an unwanted second phase regardless of trisodium citrate concentrations. The thickness and grain sizes of AZO thin films decreased with increasing trisodium citrate concentration. The microstructure of AZO thin films was changed from flat to needle shaped and the morphology was smoother with increasing trisodium citrate concentrations. The AZO thin films have a high transmittance in the visible region ranging from 75 to 85% and a sharp edge from 366 to 374 nm.

  8. Influence of nanocrystalline size on optical band gap in CdSe thin films prepared by DC sputtering

    NASA Astrophysics Data System (ADS)

    Khalaf, Mohammed Khammass; ALhilli, Baha A. M.; Khudiar, Ausama I.; Alzahra, Anwar Abd

    2016-01-01

    Cadmium selenide CdSe thin films have been deposited on glass substrate by using plasma sputtering at room temperature with different times of sputtering. The CdSe thin films are characterized using XRD. The crystallite size of the film is calculated from XRD data, which is found as 12.65 nm as-deposited. It is also found that crystallite size of CdSe thin films increased with thin films thickness. The optical properties concerning the absorption spectra were studied for the prepared thin films. The energy band gaps were found to be in the range of 2.21 eV to 1.8 eV. On varying the film thickness in the range of 350 nm to 600 nm, it was found that the optical band gap increased due to the nanocrystalline size of the CdSe thin films decreased.

  9. Preparation of a novel chitosan-microcapsules/starch blend film and the study of its drug-release mechanism.

    PubMed

    Huo, Weiqiang; Xie, Gancheng; Zhang, Weixin; Wang, Wei; Shan, Junyang; Liu, Hechou; Zhou, Xiaohua

    2016-06-01

    A novel drug delivery system, chitosan-microcapsules/starch blend film for antofloxacin controlled release, was prepared, and characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (X-RD), thermogravimetry and derivative thermogravimetry (TG/DTG), and scanning electron microscopy (SEM). Following incorporation of the chitosan-microcapsules in the film matrix, the synergistic interactions between these drug-carriers were significant. The thermostability and mechanical properties of the blend film were greatly improved by the incorporation of the microcapsules. The water resistance of the blend film was enhanced by increasing the content of microcapsules, indicating that the microcapsules acted as moisture barriers. After being incorporated, chitosan-microcapsules/starch blend film shows a sustained drug release. The extent of the film degradation and microcapsules swelling in the release system indicated that the drug released of the blend film was pH-sensitive. The blend film exhibited pharmacodynamic efficacy because of the efficient drug releasing.

  10. Influence of substrate temperature on titanium oxynitride thin films prepared by reactive sputtering

    NASA Astrophysics Data System (ADS)

    Chappé, J.-M.; Martin, N.; Pierson, J. F.; Terwagne, G.; Lintymer, J.; Gavoille, J.; Takadoum, J.

    2004-03-01

    Thin films of titanium oxynitride were successfully prepared by dc reactive magnetron sputtering using a titanium metallic target, argon, nitrogen and water vapour as reactive gases. The nitrogen partial pressure was kept constant during every deposition whereas that of the water vapour was systematically changed from 0 to 0.1 Pa. These films were made at room temperature (293 K) (set A) and at 673 K (set B). The study consisted in comparing the evolution of deposition parameters like target potential or deposition rate and physical properties of films for each set. Elemental composition measurements obtained by RBS and NRA revealed a reverse and continuous evolution of nitrogen and oxygen contents. Structure and morphology of the films were analysed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Films deposited at room temperature became amorphous with an increasing supply of water vapour. A higher substrate temperature led to significant changes of the crystallographic structure: from fcc TiN without water vapour to a mixture of anatase+rutile for large amount of water vapour. The optical transmittance spectra of the film/glass substrate system were measured in the visible region as a function of the water vapour pressure. For both sets A and B, optical transmittance was influenced by the water vapour partial pressure. Electrical conductivity measured against temperature was gradually modified from metallic ( σ 300 K=1.49×10 4 S m -1) to semi-conducting behaviour ( σ 300 K=2.15 S m -1) with an increasing supply of the water vapour partial pressure. Moreover, coatings prepared at room temperature exhibited a surprising maximum of the electrical conductivity for a small amount of water vapour (set A). Such surprising evolution vanished for set B with a restricted range of conductivity from σ 300 K=1.1×10 5 to 7×10 2 S m -1.

  11. Preparation of Thin Melanin-Type Films by Surface-Controlled Oxidation.

    PubMed

    Salomäki, Mikko; Tupala, Matti; Parviainen, Timo; Leiro, Jarkko; Karonen, Maarit; Lukkari, Jukka

    2016-04-26

    The preparation of thin melanin films suitable for applications is challenging. In this work, we present a new alternative approach to thin melanin-type films using oxidative multilayers prepared by the sequential layer-by-layer deposition of cerium(IV) and inorganic polyphosphate. The interfacial reaction between cerium(IV) in the multilayer and 5,6-dihydroxyindole (DHI) in the adjacent aqueous solution leads to the formation of a thin uniform film. The oxidation of DHI by cerium(IV) proceeds via known melanin intermediates. We have characterized the formed DHI-melanin films using scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), UV-vis spectroscopy, and spectroelectrochemistry. When a five-bilayer oxidative multilayer is used, the film is uniform with a thickness of ca. 10 nm. Its chemical composition, as determined using XPS, is typical for melanin. It is also redox active, and its oxidation occurs in two steps, which can be assigned to semiquinone and quinone formation within the indole structural motif. Oxidative multilayers can also oxidize dopamine, but the reaction stops at the dopamine quinone stage because of the limited amount of the multilayer-based oxidizing agent. However, dopamine oxidation by Ce(IV) was studied also in solution by UV-vis spectroscopy and mass spectrometry in order to verify the reaction mechanism and the final product. In solution, the oxidation of dopamine by cerium shows that the indole ring formation takes place already at low pH and that the mass spectrum of the final product is practically identical with that of commercial melanin. Therefore, layer-by-layer formed oxidative multilayers can be used to deposit functional melanin-type thin films on arbitrary substrates by a surface-controlled reaction.

  12. [Preparation of large area Al-ZnO thin film by DC magnetron sputtering].

    PubMed

    Jiao, Fei; Liao, Cheng; Han, Jun-Feng; Zhou, Zhen

    2009-03-01

    Solar cells of p-CIS/n-buffer/ZnO type, where CIS is (CuInS2, CuInSe2 or intermediates, are thin-film-based devices for the future high-efficiency and low-cost photovoltaic devices. As important thin film, the properties of Al-doped ZnO (AZO) directly affect the parameter of the cell, especially for large volume. In the present paper, AZO semiconductor transparent thin film on soda-lime glass was fabricated using cylindrical zinc-aluminum target, which can not only lower the cost of the target but also make the preparation of large area AZO thin film more easily. Using the DC magnet sputtering techniques and rolling target, high utilization efficiency of target was achieved and large area uniform and directional film was realized. An introduction to DC magnet sputtering techniques for large area film fabrication is given. With different measurement methods, such as X-ray diffraction (XRD) and scan electron microscope (SEM), we analyzed large size film's structure, appearance, and electrical and optical characteristics. The XRD spectrum indicated that the AZO film shows well zinc-blende structure with a preferred (002) growth and the c-axis is oriented normal to the substrate plane. The lattice constant is 5.603 9 nm and the mismatch with CdS thin film is only 2 percent. It absolutely satisfied the demand of the GIGS solar cell. The cross-section of the AZO thin film indicates the columnar structure and the surface morphology shows that the crystal size is about 50 nm that is consistent with the result of XRD spectrum. By the optical transmission curve, not only the high transmission rate over 85 percent in the visible spectrum between 400 nm and 700 nm was showed but also the band gap 3.1 eV was estimated. And all these parameters can meet the demand of the large area module of GIGS solar cell. The result is that using alloy target and Ar gas, and controlling the appropriate pressure of oxygen, we can get directional, condensed, uniform, high transmitting rate, low

  13. Nanoplate-like tungsten trioxide (hydrate) films prepared by crystal-seed-assisted hydrothermal reaction

    NASA Astrophysics Data System (ADS)

    Wang, P.; Yang, L.; Dai, B.; Yang, Z.; Guo, S.; Zhu, J.

    2017-07-01

    Vertically-aligned WO3 nanoplates on transparent conducting fluorine-doped tin oxide (FTO) glass were prepared by a facile template-free crystal-seed-assisted hydrothermal method. The effects of the hydrothermal temperature and reaction time on the crystal structure and morphology of the products were investigated by XRD and SEM. The XRD results showed that the as-prepared thin films obtained below 150∘C comprised orthorhombic WO3 ṡ H2O and completely converted to monoclinic WO3 at 180∘C. It was also noted that there was a phase transformation from orthorhombic to monoclinic by increasing the reaction time from 1 to 12 h. SEM analysis revealed that WO3 thin films are composed of plate-like nanostructures.

  14. Interfacial reactions and microstructure of BaTiO 3 films prepared using fluoride precursor method

    NASA Astrophysics Data System (ADS)

    Fujihara, Shinobu; Schneller, Theodor; Waser, Rainer

    2004-01-01

    Interfacial reactions of BaF 2 and TiO 2 were investigated in preparing BaTiO 3 thin films using a fluoride precursor method. Trifluoroacetate solutions were prepared from barium acetate, titanium tetraisopropoxide (TTIP), and trifluoroacetic acid (TFA, CF 3COOH) with additives such as water and acetylacetone. The solutions were deposited on platinized Si wafers by spin-coating, were pyrolysed at 400 °C in air and were finally heated typically at 700 °C in a water vapor atmosphere. The perovskite BaTiO 3 phase was obtained although a small portion of BaF 2 remained unreacted. Thus, the films were characterized as the mixture of BaTiO 3, BaF 2, and amorphous TiO 2. Influence of the solution chemistry on the phase evolution and microstructure was examined in order to discuss the reaction pathway of the perovskite phase.

  15. Photoelectric properties of Cu2O thin films prepared by room-temperature water bath

    NASA Astrophysics Data System (ADS)

    Yao, Jiang Yao; Yan, Li; Peng, Gao Yun; De Qing, Mo; Xin, Zhong Fu

    2017-03-01

    Cu2O thin films were prepared on a Cu substrate with a room-temperature water bath in which a HF and HNO3 mixture was used as the soak solution and dilute nitric acid was used as the deposit liquid. The influences of the preparation conditions, such as the molar ratio of HNO3:HF, the reaction temperature and the reaction time on the photoelectric performance of the sample under simulated sunlight, were explored. The results of x-ray diffraction, scanning electron microscopy, energy dispersive analysis and x-ray photoelectron spectroscopy indicate that the surface of the Cu substrate was oxidized to Cu2O, which serves as a nanocomposite thin film. Additionally, the formation of a binary Cu2O/Cu nanocomposite in optimized conditions exhibits its potential for excellent photoelectric properties under simulated solar illumination.

  16. Structural and optical properties of Cu:silica nanocomposite films prepared by co-sputtering deposition

    NASA Astrophysics Data System (ADS)

    Battaglin, G.; Cattaruzza, E.; Gonella, F.; Polloni, R.; Scremin, B. F.; Mattei, G.; Mazzoldi, P.; Sada, C.

    2004-03-01

    Copper-containing silica films were synthesized by radiofrequency (rf) co-sputtering deposition technique, and then heat-treated in different annealing atmospheres, i.e. either oxidizing or reducing, with the aim to develop suitable preparation methodologies for controlling the composite structure. Characterization of the samples along the various preparation steps was performed by Rutherford backscattering spectrometry (RBS), transmission electron microscopy and optical absorption spectroscopy. The nonlinear optical coefficient n2 of the nanocomposite films was estimated by the Z-scan technique. Experimental observations showed that copper migration and aggregation depend critically on the annealing conditions, giving rise to quite different stable structures. In particular, for samples heat-treated first in air and then in a H2-Ar gas mixture, the oxidizing atmosphere drives copper towards the surface while the reducing one promotes the subsequent clusterization in a well defined region.

  17. Preparation of nickel oxide thin films at different annealing temperature by sol-gel spin coating method

    SciTech Connect

    Abdullah, M. A. R. Mamat, M. H. Ismail, A. S.; Malek, M. F.; Alrokayan, Salman A. H. Khan, Haseeb A.; Rusop, M.

    2016-07-06

    Preparation of NiO thin films at different annealing temperature by sol-gel method was conducted to synthesize the quality of the surface thin films. The effects of annealing temperature on the surface topology were systematically investigated. Our studies confirmed that the surface roughness of the thin films was increased whenever annealing temperature was increase. NiO thin films morphology structure analysis was confirmed by field emission scanning electron microscope. Surface roughness of the thin films was investigated by atomic force microscopy.

  18. Structural properties of pure and Fe-doped Yb films prepared by vapor condensation

    SciTech Connect

    Rojas-Ayala, C.; Passamani, E.C.; Suguihiro, N.M.; Litterst, F.J.; Baggio Saitovitch, E.

    2014-10-15

    Ytterbium and iron-doped ytterbium films were prepared by vapor quenching on Kapton substrates at room temperature. Structural characterization was performed by X-ray diffraction and transmission electron microscopy. The aim was to study the microstructure of pure and iron-doped films and thereby to understand the effects induced by iron incorporation. A coexistence of face centered cubic and hexagonal close packed-like structures was observed, the cubic-type structure being the dominant contribution. There is an apparent thickness dependence of the cubic/hexagonal relative ratios in the case of pure ytterbium. Iron-clusters induce a crystalline texture effect, but do not influence the cubic/hexagonal volume fraction. A schematic model is proposed for the microstructure of un-doped and iron-doped films including the cubic- and hexagonal-like structures, as well as the iron distribution in the ytterbium matrix. - Highlights: • Pure and Fe-doped Yb films have been prepared by vapor condensation. • Coexistence of fcc- and hcp-type structures was observed. • No oxide phases have been detected. • Fe-clustering does not affect the fcc/hcp ratio, but favors a crystalline texture. • A schematic model is proposed to describe microscopically the microstructure.

  19. Preparation, characterization, and antimicrobial activity of chitin nanofibrils reinforced carrageenan nanocomposite films.

    PubMed

    Shankar, Shiv; Reddy, Jeevan Prasad; Rhim, Jong-Whan; Kim, Hee-Yun

    2015-03-06

    Present study illustrates the preparation of chitin nanofibrils (CNF) reinforced carrageenan nanocomposite films by the solution-casting technique. CNF was prepared by acid hydrolysis of chitin, followed by high speed homogenization and sonication. FTIR result demonstrated that the chemical structure of chitin had not changed after acid hydrolysis. However, the crystalinity of CNF was found to be higher than chitin. The crystallite size of chitin and CNF was 4.73 and 6.27 nm, respectively. The char content at 600 °C of chitin (19.2%) was lower than the CNF (25%). The carrageenan/CNF composite films were smooth and flexible and the CNF was dispersed uniformly in the carrageenan polymer matrix. The tensile strength and modulus of carrageenan film were increased significantly (p<0.05) after CNF reinforcement with up to 5 wt%, however, elongation at break, water vapor permeability, and transparency decreased slightly. Carrageenan/CNF nanocomposite films showed strong antibacterial activity against a Gram-positive food-borne pathogen, Listeria monocytogenes.

  20. Oligosilsesquioxanes as versatile building blocks for the preparation of self-assembled thin films.

    PubMed

    Cassagneau, Thierry; Caruso, Frank

    2002-07-10

    A self-assembly approach to the preparation of nanocomposite siliceous thin films by using oligosilsesquioxanes as building blocks is presented. Poly(styrene-4-sulfonate), PSS, and octa(3-aminopropyl)silsesquioxane, NSi8, were layer-by-layer (LbL) assembled onto planar substrates and polystyrene (PS) particles, thus forming composite multilayers. We have clarified the binding properties of NSi8 to PSS by examining the pH influence on film buildup by microelectrophoresis (zeta-potential) and quartz crystal microgravimetry (QCM). The regular growth of PSS/NSi8 multilayers on planar supports was confirmed by surface plasmon resonance (SPR) spectroscopy and QCM. By applying the LbL coating procedure to spherical templates, we prepared compact, microporous hollow silica spheres by calcining PS spheres coated with (poly(allylamine hydrochloride) (PAH)/PSS)(2)/(NSi8/PSS)(n) (n varying from 3 to 12), at 750 degrees C, because of sintering of the octameric clusters (NSi8). Hollow spheres derived from coatings with n = 3 drastically altered in size (relative to the template core), depending on the size of the PS particles used. The novelty of this method for the nanofabrication of siliceous films stems from the use of well-defined and discrete building blocks, such as NSi8, leading to homogeneous organic-silica composite films as well as individual siliceous particles of variable size and shape.

  1. Cell-compatible conducting polyaniline films prepared in colloidal dispersion mode.

    PubMed

    Kašpárková, Věra; Humpolíček, Petr; Capáková, Zdenka; Bober, Patrycja; Stejskal, Jaroslav; Trchová, Miroslava; Rejmontová, Petra; Junkar, Ita; Lehocký, Marián; Mozetič, Miran

    2017-09-01

    Conducting polyaniline can be prepared and modified using several procedures, all of which can significantly influence its applicability in different fields of biomedicine or biotechnology. The modifications of surface properties are crucial with respect to the possible applications of this polymer in tissue engineering or as biosensors. Innovative technique for preparing polyaniline films via in-situ polymerization in colloidal dispersion mode using four stabilizers (poly-N-vinylpyrrolidone; sodium dodecylsulfate; Tween 20 and Pluronic F108) was developed. The surface energy, conductivity, spectroscopic features, and cell compatibility of thin polyaniline films were determined using contact-angle measurement, the van der Pauw method, Fourier-transform infrared spectroscopy, and assay conducted on mouse fibroblasts, respectively. The stabilizers significantly influenced not only the surface and electrical properties of the films but also their cell compatibility. Sodium dodecylsulfate seems preferentially to combine both the high conductivity and good cell compatibility. Moreover, the films with sodium dodecylsulfate were non-irritant for skin, which was confirmed by their in-vitro exposure to the 3D-reconstructed human tissue model. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Preparation of Organometal Halide Perovskite Photonic Crystal Films for Potential Optoelectronic Applications.

    PubMed

    Schünemann, Stefan; Chen, Kun; Brittman, Sarah; Garnett, Erik; Tüysüz, Harun

    2016-09-28

    Herein, a facile method for the preparation of organometal halide perovskite (OHP) thin films in photonic crystal morphology is presented. The OHP photonic crystal thin films with controllable porosity and thicknesses between 2 μm and 6 μm were prepared on glass, fluorine-doped tin oxide (FTO), and TiO2 substrates by using a colloidal crystal of polystyrene microspheres as a template to form an inverse opal structure. The composition of OHP could be straightforwardly tuned by varying the halide anions. The obtained OHP inverse opal films possess large ordered domains with a periodic change of the refractive index, which results in pronounced photonic stop bands in the visible light range. By changing the diameter of the polystyrene microspheres, the position of the photonic stop band can be tuned through the visible spectrum. This developed methodology can be used as blueprint for the synthesis of various OHP films that could eventually be used as more effective light harvesting materials for diverse applications.

  3. Preparation of titanium dioxide films on etched aluminum foil by vacuum infiltration and anodizing

    NASA Astrophysics Data System (ADS)

    Xiang, Lian; Park, Sang-Shik

    2016-12-01

    Al2O3-TiO2 (Al-Ti) composite oxide films are a promising dielectric material for future use in capacitors. In this study, TiO2 films were prepared on etched Al foils by vacuum infiltration. TiO2 films prepared using a sol-gel process were annealed at various temperatures (450, 500, and 550 °C) for different time durations (10, 30, and 60 min) for 4 cycles, and then anodized at 100 V. The specimens were characterized using X-ray diffraction, field emission scanning electron microscopy, and field emission transmission electron microscopy. The results show that the tunnels of the specimens feature a multi-layer structure consisting of an Al2O3 outer layer, an Al-Ti composite oxide middle layer, and an aluminum hydrate inner layer. The electrical properties of the specimens, such as the withstanding voltage and specific capacitance, were also measured. Compared to specimens without TiO2 coating, the specific capacitances of the TiO2-coated specimens are increased. The specific capacitance of the anode Al foil with TiO2 coating increased by 42% compared to that of a specimen without TiO2 coating when annealed at 550 °C for 10 min. These composite oxide films could enhance the specific capacitance of anode Al foils used in dielectric materials.

  4. Novel silk fibroin films prepared by formic acid/hydroxyapatite dissolution method.

    PubMed

    Ming, Jinfa; Liu, Zhi; Bie, Shiyu; Zhang, Feng; Zuo, Baoqi

    2014-04-01

    Bombyx mori silk fibroin from the silkworm was firstly found to be soluble in formic acid/hydroxyapatite system. The rheological behavior of silk fibroin solution was significantly influenced by HAp contents in dissolved solution. At the same time, silk fibroin nanofibers were observed in dissolved solution with 103.6±20.4nm in diameter. Moreover, the structure behavior of SF films prepared by formic acid/hydroxyapatite dissolution method was examined. The secondary structure of silk fibroin films was attributed to silk II structure (β-sheet), indicating that the hydroxyapatite contents in dissolved solution were not significantly affected by the structure of silk fibroin. The X-ray diffraction results exhibited obviously hydroxyapatite crystalline nature existing in silk fibroin films; however, when the hydroxyapatite content was 5.0wt.% in dissolved solution, some hydroxyapatite crystals were converted to calcium hydrogen phosphate dehydrate in silk fibroin dissolution process. This result was also confirmed by Fourier transform infrared analysis and DSC measurement. In addition, silk fibroin films prepared by this dissolution method had higher breaking strength and extension at break. Based on these analyses, an understanding of novel SF dissolution method may provide an additional tool for designing and synthesizing advanced materials with more complex structures, which should be helpful in different fields, including biomaterial applications.

  5. Photosensitive Schottky-type heterojunctions prepared by the drawing of graphite films

    NASA Astrophysics Data System (ADS)

    Brus, V. V.; Maryanchuk, P. D.

    2014-04-01

    Graphite/n-CdTe Schottky-type heterojunctions were prepared by means of a very simple and low-cost method: the drawing of graphite films on the rough surface of mechanically polished n-CdTe single crystal substrates. The unoptimized heterojunctions showed promising, rectifying, and photoelectrical parameters. The obtained results represent a good starting point for the further development of the simple and low-cost heterojunction photodiodes and gas sensors.

  6. Preparation of Optically Transparent Films of Poly(methyl methacrylate) (PMMA) and Montmorillonite

    DTIC Science & Technology

    2001-11-01

    methacrylate] [PMMA] and Montmorillonite DISTRIBUTION: Approved for public release, distribution unlimited This paper is part of the following report...Society V6.4 Preparation of Optically Transparent Films of Poly(methyl methacrylate) (PMMA) and Montmorillonite Elena Vasiliul, Chyi-Shan Wang"’ 2...exchanged with 1.40 meq/g of dimethyl dehydrogenated tallow ammonium from a sodium montmorillonite , Cloisite Na+ (CNa). Since the cation-exchange

  7. Preparation, Characterization and Thermal Degradation of Polyimide (4-APS/BTDA)/SiO2 Composite Films

    PubMed Central

    Ahmad, Mansor Bin; Gharayebi, Yadollah; Salit, Mohd. Sapuan; Hussein, Mohd. Zobir; Ebrahimiasl, Saeideh; Dehzangi, Arash

    2012-01-01

    Polyimide/SiO2 composite films were prepared from tetraethoxysilane (TEOS) and poly(amic acid) (PAA) based on aromatic diamine (4-aminophenyl sulfone) (4-APS) and aromatic dianhydride (3,3,4,4-benzophenonetetracarboxylic dianhydride) (BTDA) via a sol-gel process in N-methyl-2-pyrrolidinone (NMP). The prepared polyimide/SiO2 composite films were characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM) and thermogravimetric analysis (TGA). The FTIR results confirmed the synthesis of polyimide (4-APS/BTDA) and the formation of SiO2 particles in the polyimide matrix. Meanwhile, the SEM images showed that the SiO2 particles were well dispersed in the polyimide matrix. Thermal stability and kinetic parameters of the degradation processes for the prepared polyimide/SiO2 composite films were investigated using TGA in N2 atmosphere. The activation energy of the solid-state process was calculated using Flynn–Wall–Ozawa’s method without the knowledge of the reaction mechanism. The results indicated that thermal stability and the values of the calculated activation energies increased with the increase of the TEOS loading and the activation energy also varied with the percentage of weight loss for all compositions. PMID:22606014

  8. Preparation, characterization and thermal degradation of polyimide (4-APS/BTDA)/SiO(2) composite films.

    PubMed

    Ahmad, Mansor Bin; Gharayebi, Yadollah; Salit, Mohd Sapuan; Hussein, Mohd Zobir; Ebrahimiasl, Saeideh; Dehzangi, Arash

    2012-01-01

    Polyimide/SiO(2) composite films were prepared from tetraethoxysilane (TEOS) and poly(amic acid) (PAA) based on aromatic diamine (4-aminophenyl sulfone) (4-APS) and aromatic dianhydride (3,3,4,4-benzophenonetetracarboxylic dianhydride) (BTDA) via a sol-gel process in N-methyl-2-pyrrolidinone (NMP). The prepared polyimide/SiO(2) composite films were characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM) and thermogravimetric analysis (TGA). The FTIR results confirmed the synthesis of polyimide (4-APS/BTDA) and the formation of SiO(2) particles in the polyimide matrix. Meanwhile, the SEM images showed that the SiO(2) particles were well dispersed in the polyimide matrix. Thermal stability and kinetic parameters of the degradation processes for the prepared polyimide/SiO(2) composite films were investigated using TGA in N(2) atmosphere. The activation energy of the solid-state process was calculated using Flynn-Wall-Ozawa's method without the knowledge of the reaction mechanism. The results indicated that thermal stability and the values of the calculated activation energies increased with the increase of the TEOS loading and the activation energy also varied with the percentage of weight loss for all compositions.

  9. Initial Study on Thin Film Preparation of Carbon Nanodots Composites as Luminescence Material

    NASA Astrophysics Data System (ADS)

    Iskandar, F.; Aimon, A. H.; Akmaluddin, A. R.; Nuryadin, B. W.; Abdullah, M.

    2016-08-01

    Nowadays, the developments of phosphors materials require elements without noble metals and simple production process. Carbon nanodots (C-dots) are one of phosphor materials with wide range of emission band, and high biocompatibility. In this research thin film carbon nanodots composite have been prepared by spin coating method. Prior deposition, powder carbon nanodots were synthesized from a mixture of commercial urea as the nitrogen sources and citric acid as a carbon source by using hydrothermal and microwave-assisted heating method. The prepared powder was dispersed in transparent epoxy resin and then coated on glass substrate. The photoluminescence result for sample with 0.035 g citric acid exhibited an intense, single, homogeneous and broad spectrum with yellowish emission upon excitation at 365 nm. The Fourier Transform Infrared Spectroscopy (FTIR) result showed the existences of C=C, C-H, C=O, N-H and O-H functional groups which confirmed the quality of the sample. Further, based on UV-Vis measurement, the prepared thin film was highly transparent (transmittance 90%) with estimated film thickness around 764 nm. This result may open an opportunity for optoelectronic devices.

  10. Preparation and characterization of hydrophobic polymeric films that are thromboresistant via nitric oxide release.

    PubMed

    Mowery, K A; Schoenfisch, M H; Saavedra, J E; Keefer, L K; Meyerhoff, M E

    2000-01-01

    The preparation of hydrophobic polymer films (polyurethane and poly(vinyl chloride)) containing nitric oxide (NO)-releasing diazeniumdiolate functions is reported as a basis for improving the thromboresistivity of such polymeric materials for biomedical applications. Several different approaches for preparing NO-releasing polymer films are presented, including: (1) dispersion of diazeniumdiolate molecules within the polymer matrix; (2) covalent attachment of the diazeniumdiolate to the polymer backbone; and (3) ion-pairing of a diazeniumdiolated heparin species to form an organic soluble complex that can be blended into the polymer. Each approach is characterized in terms of NO release rates and in vitro biocompatibility. Results presented indicate that the polymer films prepared by each approach release NO for variable periods of time (10-72 h), although they differ in the mechanism, location and amount of NO released. In vitro platelet adhesion studies demonstrate that the localized NO release may prove to be an effective strategy for improving blood compatibility of polymer materials for a wide range of medical devices.

  11. Gelatin based bio-films prepared from grey triggerfish' skin influenced by enzymatic pretreatment.

    PubMed

    Souissi, Nabil; Abdelhedi, Ola; Mbarek, Aïcha; Kammoun, Wassim; Kechaou, Hela; Nasri, Moncef

    2017-09-08

    Gelatins from grey triggerfish skin were extracted with different methods The supplementation by pepsin (PG) improved the yield of extraction when compared with untreated gelatin (UG) and acidic gelatin (AG). The outputs of gelatins AG, UG and PG, obtained respectively, with acitic acid, glycine buffer and glycine buffer added with 5U of pepsin/g of the skin beforehand treated by alkali, were 6.9%, 7.9% and 9.7%, respectively. The enzymatic treatment of the alkali-pretreated skin of grey triggerfish altered the electrophoresis profile, biophysical, gellification, rheological and thermal properties of the prepared gelatins extracted under acidic condition. However, the untreated gelatin obtained without pepsin exhibited the highest transition and enthaply temperatures. In addition, the properties of the prepared films were interconnected to their microstructure as demonstrated by scanning electron microscopy. Furthermore, films with PG and UG had a regular surface and a more condensed structure, however films prepared with AG had rougher surface. Copyright © 2017. Published by Elsevier B.V.

  12. Preparation of dilute magnetic semiconductor films by metalorganic chemical vapor deposition

    NASA Technical Reports Server (NTRS)

    Nouhi, Akbar (Inventor); Stirn, Richard J. (Inventor)

    1988-01-01

    A method for preparation of a dilute magnetic semiconductor (DMS) film is provided, in which a Group II metal source, a Group VI metal source and a transition metal magnetic ion source are pyrolyzed in the reactor of a metalorganic chemical vapor deposition (MOCVD) system by contact with a heated substrate. As an example, the preparation of films of Cd(sub 1-x)Mn(sub x)Te, in which 0 is less than or equal to x less than or equal to 0.7, on suitable substrates (e.g., GaAs) is described. As a source of manganese, tricarbonyl (methylcyclopentadienyl) manganese (TCPMn) is employed. To prevent TCPMn condensation during its introduction into the reactor, the gas lines, valves and reactor tubes are heated. A thin-film solar cell of n-i-p structure, in which the i-type layer comprises a DMS, is also described; the i-type layer is suitably prepared by MOCVD.

  13. Preparation of personalized-dose salbutamol sulphate oral films with thermal ink-jet printing.

    PubMed

    Buanz, Asma B M; Saunders, Mark H; Basit, Abdul W; Gaisford, Simon

    2011-10-01

    To evaluate the use of thermal ink-jetting as a method for dosing drugs onto oral films. A Hewlett-Packard printer cartridge was modified so that aqueous drug solutions replaced the ink. The performance of the printer as a function of print solution viscosity and surface tension was determined; viscosities between 1.1 and 1.5 mm(2) s(-1) were found to be optimal, while surface tension did not affect deposition. A calibration curve for salbutamol sulphate was prepared, which demonstrated drug deposition onto an acetate film varied linearly with concentration (r(2) = 0.9992). The printer was then used to deposit salbutamol sulphate onto an oral film made of potato starch. It was found that when doses were deposited in a single pass under the print head, then the measured dose was in good agreement with the theoretical dose. With multiple passes the measured dose was always significantly less than the theoretical dose. It is proposed that the losses arise from erosion of the printed layer by shearing forces during paper handling. The losses were predictable, and the variance in dose deposited was always less than the BP limits for tablet and oral syrup salbutamol sulphate preparations. TIJ printing offers a rapid method for extemporaneous preparation of personalized-dose medicines.

  14. Designer stabilizer for preparation of pristine graphene/polysiloxane films and networks.

    PubMed

    Parviz, Dorsa; Yu, Ziniu; Hedden, Ronald C; Green, Micah J

    2014-10-21

    A conductive polymer film containing pristine graphene was prepared by designing a polysiloxane-based stabilizer for graphene. The stabilizer was prepared by grafting 1-ethynylpyrene to the backbone of a poly(dimethylsiloxane)-co-(methylhydrosiloxane) (PDMS-PHMS) random copolymer by Pt-catalyzed hydrosilylation with a SiH-ethynyl ratio of 1.0 : 1.3. The resulting copolymer was able to stabilize pristine graphene in chloroform solution viaπ-π interactions between the pyrene groups and graphene sheets. TEM and SEM images show a homogeneous distribution of the graphene in cast films deposited from chloroform. The conductivity of a graphene/PDMS film prepared from copolymer with a 1.7 vol.% graphene loading was measured as 220 S m(-1) after the removal of unbound polymer by a simple separation technique. With a SiH-ethynyl ratio of 1.7 : 1.0, the copolymer self-crosslinked at 110 °C in the presence of adventitious moisture, providing a straightforward route to incorporate graphene into silicone elastomers. The crosslinking process (with and without added graphene) was characterized by FT-IR spectroscopy and by swelling and extraction of the obtained networks. Again, unbound polymer removal increases the conductivity of the composite.

  15. Preparation and Optical Properties of Zirconium-Titanium-Oxide Thin Films by Reactive Sputtering

    NASA Astrophysics Data System (ADS)

    Matsumoto, Hironaga; Sekine, Masato; Miura, Noboru; Nakano, Ryotaro; Matsumoto, Setsuko

    2005-02-01

    Zirconium-titanium-oxide thin films were prepared by multi-target rf reactive sputtering using metallic targets of zirconium and titanium. The compositional ratio of zirconium to titanium in the thin films was precisely controlled through rf power. Zirconium and titanium in the thin films were found to exist as mixtures of chemically bonded ZrO2 and TiO2 from XPS spectra. The zirconium-titanium-oxide thin films with compositional ratio x<0.42 were identified to have a tetragonal crystal structure, whereas those with x≥q 0.42 were identified to be in the amorphous state. The refractive index of the zirconium-titanium-oxide thin film at a wavelength of 550 nm changed from 2.25 to 2.55 according to compositional ratio x, and the dispersion of the refractive index was analyzed using the Lorentz oscillator model with four oscillators. It was clarified that the estimated oscillator energies E1 (10.5 eV) and E2 (6.5 eV) correspond to zirconium oxide, and that E3 (5.5 eV) and E4 (4.3 eV) correspond to titanium oxide from fundamental absorption spectra and photoconductivity.

  16. Preparation of lead-zirconium-titanium film and powder by electrodeposition

    DOEpatents

    Bhattacharya, Raghu N.; Ginley, David S.

    1995-01-01

    A process for the preparation of lead-zirconium-titanium (PZT) film and powder compositions. The process comprises the steps of providing an electrodeposition bath, providing soluble salts of lead, zirconium and titanium metals to this bath, electrically energizing the bath to thereby direct ions of each respective metal to a substrate electrode and cause formation of metallic particles as a recoverable film of PZT powder on the electrode, and also recovering the resultant film as a powder. Recovery of the PZT powder can be accomplished by continually energizing the bath to thereby cause powder initially deposited on the substrate-electrode to drop therefrom into the bath from which it is subsequently removed. A second recovery alternative comprises energizing the bath for a period of time sufficient to cause PZT powder deposition on the substrate-electrode only, from which it is subsequently recovered. PZT film and powder so produced can be employed directly in electronic applications, or the film and powder can be subsequently oxidized as by an annealing process to thereby produce lead-zirconium-titanium oxide for use in electronic applications.

  17. Preparation of lead-zirconium-titanium film and powder by electrodeposition

    DOEpatents

    Bhattacharya, R.N.; Ginley, D.S.

    1995-10-31

    A process is disclosed for the preparation of lead-zirconium-titanium (PZT) film and powder compositions. The process comprises the steps of providing an electrodeposition bath, providing soluble salts of lead, zirconium and titanium metals to this bath, electrically energizing the bath to thereby direct ions of each respective metal to a substrate electrode and cause formation of metallic particles as a recoverable film of PZT powder on the electrode, and also recovering the resultant film as a powder. Recovery of the PZT powder can be accomplished by continually energizing the bath to thereby cause powder initially deposited on the substrate-electrode to drop therefrom into the bath from which it is subsequently removed. A second recovery alternative comprises energizing the bath for a period of time sufficient to cause PZT powder deposition on the substrate-electrode only, from which it is subsequently recovered. PZT film and powder so produced can be employed directly in electronic applications, or the film and powder can be subsequently oxidized as by an annealing process to thereby produce lead-zirconium-titanium oxide for use in electronic applications. 4 figs.

  18. Structure and morphology of thin films of linear aliphatic polyesters prepared by spin-coating.

    PubMed

    Hernández, J J; Rueda, D R; García-Gutiérrez, M C; Nogales, A; Ezquerra, T A; Soccio, M; Lotti, N; Munari, A

    2010-07-06

    Thin films, with thicknesses from 10 to 400 nm of linear aliphatic polyesters (X, Y), based on propylenediol (X = 3) and on dicarboxylic acid of different chain length (Y = 2, 3, and 4 CH(2) units) were prepared by spin coating of CHCl(3) polymer solutions with different polymer concentrations. Morphology and structure of the spin coated thin films were investigated by atomic force microscopy (AFM) and by grazing incidence X-ray scattering techniques at small, (GISAXS) and wide angles (GIWAXS). AFM revealed a strong dewetting for all three polymers for coatings thinner than 100 nm. The polymer films are clearly semicrystalline for thicknesses higher than 50 nm. GIWAXS of the thicker films revealed their oriented crystalline nature. An edge-on-lamellae morphology is clearly shown by the AFM-phase images even for relatively thin films. SAXS with the beam parallel to the sample plane also support the presence of lamellae perpendicular to the substrate. The use of a mu-beam helped to interpret the GIWAXS patterns and allowed to obtain oriented WAXS patterns from melt solidified filaments. Thus, a crystal chain packing is proposed for the three polymers and consequently the indexing of the observed reflections. Accordingly, the polymer chains lie parallel to the substrate being the bc plane of the monoclinic crystal unit cell parallel to the substrate.

  19. In Situ Preparation of Metal Halide Perovskite Nanocrystal Thin Films for Improved Light-Emitting Devices.

    PubMed

    Zhao, Lianfeng; Yeh, Yao-Wen; Tran, Nhu L; Wu, Fan; Xiao, Zhengguo; Kerner, Ross A; Lin, YunHui L; Scholes, Gregory D; Yao, Nan; Rand, Barry P

    2017-04-25

    Hybrid organic-inorganic halide perovskite semiconductors are attractive candidates for optoelectronic applications, such as photovoltaics, light-emitting diodes, and lasers. Perovskite nanocrystals are of particular interest, where electrons and holes can be confined spatially, promoting radiative recombination. However, nanocrystalline films based on traditional colloidal nanocrystal synthesis strategies suffer from the use of long insulating ligands, low colloidal nanocrystal concentration, and significant aggregation during film formation. Here, we demonstrate a facile method for preparing perovskite nanocrystal films in situ and that the electroluminescence of light-emitting devices can be enhanced up to 40-fold through this nanocrystal film formation strategy. Briefly, the method involves the use of bulky organoammonium halides as additives to confine crystal growth of perovskites during film formation, achieving CH3NH3PbI3 and CH3NH3PbBr3 perovskite nanocrystals with an average crystal size of 5.4 ± 0.8 nm and 6.4 ± 1.3 nm, respectively, as confirmed through transmission electron microscopy measurements. Additive-confined perovskite nanocrystals show significantly improved photoluminescence quantum yield and decay lifetime. Finally, we demonstrate highly efficient CH3NH3PbI3 red/near-infrared LEDs and CH3NH3PbBr3 green LEDs based on this strategy, achieving an external quantum efficiency of 7.9% and 7.0%, respectively, which represent a 40-fold and 23-fold improvement over control devices fabricated without the additives.

  20. Preparation and characterization of a novel bionanocomposite edible film based on pectin and crystalline nanocellulose.

    PubMed

    Chaichi, Maryam; Hashemi, Maryam; Badii, Fojan; Mohammadi, Abdorreza

    2017-02-10

    In this study, for the first time, the edible pectin film was reinforced by crystalline nanocelullose (CNC). The incorporation of three levels of CNC (2, 5 and 7% w/w) on mechanical, thermal and water vapor barrier properties of pectin-based biodegradable film were investigated using solution casting evaporation method for film preparation. The optimum result was obtained through the nanocomposite film with 5% CNC in terms of mechanical and water vapor properties as the tensile strength increased up to 84% and water vapor permeability decreased by 40%. However, analysis of thermal properties indicated no significant effect of CNC on glass transition temperature. X-ray diffraction (XRD) studies illustrated a positive correlation between the degree of crystallinity and the CNC level. Moreover, AFM images presented good dispersion of CNC in the pectin matrix suggesting appropriate interaction between the filler and matrix, which is in agreement with mechanical consequences. According to the overall results, the reinforcement of pectin film with 5% CNC compared to other strengthening strategies had a higher effect and therefore it could be introduced as a good candidate for the development of strong, completely biodegradable and renewable food packaging material.

  1. Dysprosium-doped chalcogenide films prepared by pulsed-laser deposition

    NASA Astrophysics Data System (ADS)

    Nazabal, Virginie; Nemec, Petr; Jedelský, Jaroslav; Duverger, Claire; Le Person, Jenny; Adam, Jean-Luc; Frumar, Miloslav

    2004-08-01

    The chalcogenide glasses possess interesting optical properties such as a good transmission in the nIR-mIR wavelength region, high linear and non-linear refractive index and photosensitivity, which allows holographic patterns writing. Moreover, their low-phonon energy makes them good candidates for optical amplification. In order to design an integrated circuit on chalcogenide glasses, the pulsed laser deposition (PLD) technique is a suitable method for deposition of glass with complex composition. Amorphous Ge-Ga-Sb-S films (pure and dysprosium doped) were prepared by PLD using different energy of the laser beam pulses. Compositional, morphological and structural characteristics of the films were studied by MEB-EDS, atomic force, scanning electron microscopy, X-ray diffraction and Raman spectroscopy analyses. The photo-luminescence of Dy doped Ge-Ga-Sb-S films was investigated. The emission band centered at 1340 nm corresponding to 6F11/2, 6H9/2-6H15/2 electron transitions of Dy3+ ions was identified in luminescence spectra of dysprosium doped thin films. A study of the optical properties and the effects of exposure and thermal annealing below the glass transition temperature on the optical parameters of thin films from the Ge-Ga-Sb-S system will be presented.

  2. Some aspects of atom probe specimen preparation and analysis of thin film materials.

    PubMed

    Thompson, G B; Miller, M K; Fraser, H L

    2004-07-01

    Some of the factors in the preparation of atom probe specimens of metallic multilayer thin films have been investigated. A series of Ti/Nb multilayer films were sputtered deposited on n-doped Si [001] substrates with either 5 or 0.05Omega cm resistivity. Each wafer was pre-fabricated into a series of 5 microm x 5 microm x approximately 80 microm island posts by photolithography and reactive ion etching. Once the film was grown on the wafer, a Si post was mounted to either a tungsten or stainless steel fine tip needle that was mechanically crimped to a Cu tube for handling. The specimen was then loaded into a Focus Ion Beam instrument where a sacrificial Pt cap was in situ deposited onto the surface of the film and subsequently annularly ion milled into the appropriate geometry. The Pt cap was found to be an effective method in reducing Ga ion damage and implantation into the film during milling. The multilayers deposited on the high resistivity Si exhibited uncontrolled field evaporation which lead to high mass tails in the mass spectra, a reduction in the mass resolution, high background noise, propensity for "flash-failure", and a variation in the apparent layer thickness as the experiment elapsed in time. The multilayers deposited on lower resistivity Si did not suffer from these artifacts.

  3. Preparation and Characterization of Space Durable Polymer Nanocomposite Films from Functionalized Carbon Nanotubes

    NASA Technical Reports Server (NTRS)

    Delozier, D. M.; Connell, J. W.; Smith, J. G.; Watson, K. A.

    2003-01-01

    Low color, flexible, space durable polyimide films with inherent, robust electrical conductivity have been under investigation as part of a continuing materials development activity for future NASA space missions involving Gossamer structures. Electrical conductivity is needed in these films to dissipate electrostatic charge build-up that occurs due to the orbital environment. One method of imparting conductivity is through the use of single walled carbon nanotubes (SWNTs). However, the incompatibility and insolubility of the SWNTs severely hampers their dispersion in polymeric matrices. In an attempt to improve their dispersability, SWNTs were functionalized by the reaction with an alkyl hydrazone. After this functionalization, the SWNTs were soluble in select solvents and dispersed more readily in the polymer matrix. The functionalized SWNTs were characterized by Raman spectroscopy and thermogravimetric analysis (TGA). The functionalized nanotubes were dispersed in the bulk of the films using a solution technique. The functionalized nanotubes were also applied to the surface of polyimide films using a spray coating technique. The resultant polyimide nanocomposite films were evaluated for nanotube dispersion, electrical conductivity, mechanical, and optical properties and compared with previously prepared polyimide-SWNT samples to assess the effects of SWNT functionalization.

  4. The investigation of carbon nitride films prepared at various arc currents by vacuum cathode arc method

    NASA Astrophysics Data System (ADS)

    Zhou, Zhimin; Xia, Lifang

    2002-08-01

    The carbon nitride films have been prepared in the arc currents range of 20-60 A at the Ar/N2 atmosphere of 50/400 sccm by the vacuum cathode arc deposition method. The properties of the films were characterized by x-ray photoelectron spectroscopy, Raman spectroscopy, Fourier transform infrared spectroscopy and nanoindentation. The N concentration showed a maximum of 35 at% at 20 A and decreased gradually with the arc currents. The films below 40 A consisted of linear polymeric-like component and sp2 graphitic cluster. With the increasing of the arc current from 20 to 40 A, the ID/IG rose and the photoluminescence (PL) fell gradually, which resulted from the development of the sp2 graphitic phase and the decrease of the polymeric-like phase. As a result, the CC bonds increased and sp3CN and sp2CN decreased. Above 40 A, with the increasing of arc currents, ID/IG fell and the PL increased gradually, which reflected the decreasing of sp2 graphitic phase and the modification of C and N atoms in sp2 cluster. The CC bonds and sp3CN fell and the sp2CN rose. The nanohardness of films showed increasing tendency with the arc currents. The variation of the relative ratio and the average energy of N-containing species and C-containing species at the atmosphere would be responsible for the change in the properties of films.

  5. Preparation of γ-Mercaptopropyltrimethoxysilane's Films to Protect Steel Against Corrosion

    NASA Astrophysics Data System (ADS)

    Deyá, Cecilia

    2015-03-01

    Traditionally, chromates and phosphates were used as pretreatments for metals to protect them from corrosion during a temporary period. Nowadays, due to their toxicity, replacements are being study. The most studied compounds are based on silanes and, among them, glicidoxypropyltrimethoxysilane, aminopropyltrimethoxysilane, and mercaptopropyltrimethoxysilane are the most important ones. The objective of this research work was to study the anticorrosive protection afforded by films of γ-mercaptopropyltrimethoxysilane deposited on SAE 1010 steel in order to select the optimum preparation conditions. The films were applied on sandblasted steel after 24 or 48 h of hydrolysis of the silane in a water/methanol solution (1.5/1, by volume) and cured for 10 min at 80 °C or for 1 h at 100 °C. In order to evaluate the characteristics of the films, Fourier transformed infrared spectroscopy was done on the films and the coated surfaces were observed by scanning electron microscopy. The anticorrosive protection afforded by the films was studied by electrochemical tests employing polarization curves (Tafel mode) in 0.5 M NaCl solution and corrosion potential measurements in NaCl 0.05 M. The best results were obtained with silane hydrolyzed for 48 h cured at 80 °C for 10 min.

  6. Preparation of metal oxide thin films using coating photolysis process with ArF excimer laser

    NASA Astrophysics Data System (ADS)

    Tsuchiya, Tetsuo; Watanabe, Akio; Imai, Yoji; Niino, Hiroyuki; Yabe, Akira; Yamaguchi, Iwao; Manabe, Takaaki; Kumagai, Toshiya; Mizuta, Susumu

    2000-11-01

    The preparation of metal oxide thin films have been developed using the metalorganic (MO) compounds coating photolysis process with ArF excimer laser irradiation at room temperature. The effect of the starting materials and irradiation method on the product films was investigated by FT-IR, UV, XRD and SEM. It was found that metal acetylacetonates or metal 2-ethylhexanoate was effective as the starting materials. When using metal acetylacetonates as the starting materials, crystallized TiO2, In2O3 and ZrO2 were obtained with ArF laser irradiation at 50 mJ/cm2 at a repetition rate of 5 Hz for 5 min. When using An-acac, Fe, Sn, or In 2-ethylhexanoate as the starting material, a two-step process consisting of both preliminary weak (10mJ/cm2) and sufficiently strong irradiation (50mJ/cm2) was found to be effective for obtaining crystallized ZnO, Fe2O3, SnO2 and In2O3 films. In addition, crystallized complex oxide thin films such as ITO, PbTo3 and PbZrO3 were successfully obtained from the metal acetylacetonates or metal 2-ethylhexanoate using MO coating photolysis process. Patterned metal oxide thin films were also obtained by the ArF laser irradiation through the photomask, followed by leaching with solvents. The crystallization mechanism was discussed from the point of view of the photochemical reaction and photothermal reaction.

  7. Preparation and Characterization of Films Extruded of Polyethylene/Chitosan Modified with Poly(lactic acid).

    PubMed

    Quiroz-Castillo, Jesús Manuel; Rodríguez-Félix, Dora Evelia; Grijalva-Monteverde, Heriberto; Lizárraga-Laborín, Lauren Lucero; Castillo-Ortega, María Mónica; Del Castillo-Castro, Teresa; Rodríguez-Félix, Francisco; Herrera-Franco, Pedro Jesús

    2014-12-30

    The use of mixtures of synthetic and natural polymers is a potential option to reduce the pollution by plastic waste. In this work, the method for the chemical modification of chitosan with poly(lactic acid) was developed; then, the preparation of films of blends of polyethylene and chitosan-poly(lactic acid) produced by an extrusion method using polyethylene-graft maleic anhydride as a compatibilizer. It was possible to obtain films with a maximum content of 20 wt% and 30 wt%, chitosan, with and without compatibilizer, respectively. Scanning electron microscope (SEM) analysis showed a homogeneous surface on all films. The addition of the compatibilizer had a significant effect on the mechanical properties of the films, such as an increase in Young's modulus and a decrease in the elongation at break; additionally, the compatibilizer promotes thermal degradation in a single step and gives the film a slight increase in thermal resistance. These results are attributed to an improved interaction in the interface of polyethylene and chitosan-poly(lactic acid), promoted by the compatibilizer.

  8. Preparation of soft magnetic FeCo-based films for writers

    SciTech Connect

    Wang Xuan; Zheng Fu; Liu Zhaoyang; Wei Fulin; Liu Xiaoxi; Wei Dan

    2009-04-01

    New soft magnetic head materials, the nanocrystalline FeCoAlOC thin films, were prepared by introducing C element in epoxy resin during rf sputtering of FeCoAlO films. When Al{sub 2}O{sub 3} was cosputtered with FeCo, soft magnetic properties of thin films were highly improved: the coercive force decreases from dozen of oersted to several oersted (H{sub ch}{approx}4.8 Oe and H{sub ce}{approx}6.5 Oe). With further addition of carbon, the thin films exhibit excellent soft magnetic properties and good high frequency response: the coercivity is as low as 1.0 Oe, with saturation B{sub s}>20 kG, permeability {mu}{sup '}>500 when f{<=}1.0 GHz, and cutoff frequency around 1.7 GHz. The measurement of microstructure shows that the good magnetic properties are correlated with the small gain size of film.

  9. Preparation and Characterization of Films Extruded of Polyethylene/Chitosan Modified with Poly(lactic acid)

    PubMed Central

    Quiroz-Castillo, Jesús Manuel; Rodríguez-Félix, Dora Evelia; Grijalva-Monteverde, Heriberto; Lizárraga-Laborín, Lauren Lucero; Castillo-Ortega, María Mónica; del Castillo-Castro, Teresa; Rodríguez-Félix, Francisco; Herrera-Franco, Pedro Jesús

    2014-01-01

    The use of mixtures of synthetic and natural polymers is a potential option to reduce the pollution by plastic waste. In this work, the method for the chemical modification of chitosan with poly(lactic acid) was developed; then, the preparation of films of blends of polyethylene and chitosan-poly(lactic acid) produced by an extrusion method using polyethylene-graft maleic anhydride as a compatibilizer. It was possible to obtain films with a maximum content of 20 wt% and 30 wt%, chitosan, with and without compatibilizer, respectively. Scanning electron microscope (SEM) analysis showed a homogeneous surface on all films. The addition of the compatibilizer had a significant effect on the mechanical properties of the films, such as an increase in Young’s modulus and a decrease in the elongation at break; additionally, the compatibilizer promotes thermal degradation in a single step and gives the film a slight increase in thermal resistance. These results are attributed to an improved interaction in the interface of polyethylene and chitosan-poly(lactic acid), promoted by the compatibilizer. PMID:28787928

  10. Uniaxial orientation of P3HT film prepared by soft friction transfer method.

    PubMed

    Imanishi, Masayoshi; Kajiya, Daisuke; Koganezawa, Tomoyuki; Saitow, Ken-Ichi

    2017-07-11

    The realization of room-temperature processes is an important factor in the development of flexible electronic devices composed of organic materials. In addition, a simple and cost-effective process is essential to produce stable working devices and to enhance the performance of a smart material for flexible, wearable, or stretchable-skin devices. Here, we present a soft friction transfer method for producing aligned polymer films; a glass substrate was mechanically brushed with a velvet fabric and poly(3-hexylthiophene) (P3HT) solution was then spin-coated on the substrate. A P3HT film with a uniaxial orientation was obtained in air at room temperature. The orientation factor was 17 times higher than that of a film prepared using a conventional friction transfer technique at a high temperature of 120 °C. In addition, an oriented film with a thickness of 40 nm was easily picked up and transferred to another substrate. The mechanism for orientation of the film was investigated using six experimental methods and theoretical calculation, and was thereby attributed to a chemical process, i.e., cellulose molecules attach to the substrate and act as a template for molecular alignment.

  11. Optical Characteristics of La-Doped ZnS Thin Films Prepared by Chemical Bath Deposition

    NASA Astrophysics Data System (ADS)

    Xie, Hai-Qing; Chen, Yuan; Huang, Wei-Qing; Huang, Gui-Fang; Peng, Ping; Peng, Li; Wang, Tai-Hong; Zeng, Yun

    2011-02-01

    Undoped and La-doped ZnS thin films are prepared by chemical bath deposition (CBD) process through the co-precipitation reaction of inorganic precursors zinc sulfate, thiosulfate ammonia and La2O3. Composition of the films is analyzed using an energy-dispersive x-ray spectroscopy (EDS). Absorption spectra and spectral transmittances of the films are measured using a double beam UV-VIS spectrophotometer (TU-1901). It is found that significant red shifts in absorption spectra and decrease in absorptivity are obtained with increasing lanthanum. Moreover, optical transmittance is increased as La is doped, with a transmittance of more than 80% for wavelength above 360 nm in La-doped ZnS thin films. Compared to pure ZnS, the band gap decreases and flat-band potential positively shifts to quasi-metal for the La-doped ZnS. These results indicate that La-doped ZnS thin films could be valuably adopted as transparent electrodes.

  12. Preparation and characterization of bionanocomposite films based on potato starch/halloysite nanoclay.

    PubMed

    Sadegh-Hassani, Fatemeh; Mohammadi Nafchi, Abdorreza

    2014-06-01

    In this research casting method was used to prepare potato starch based bio-nanocomposite films with halloysite nanoclay as the reinforcing materials. The composition included potato starch with 40% (w/w) of a mixture of sorbitol/glycerol (weight ratio of 3 to 1as plasticizer) with nanoclay (0-5% w/w). The films were dried under controlled conditions. Physicochemical properties such as solubility in water, water absorption capacity (WAC), water vapour permeability (WVP), oxygen permeability, and mechanical properties of the films were measured. Results showed that by increasing the concentration of nanoclay, mechanical properties of films were improved. Tensile strength was increased from 7.33 to 9.82MPa, and elongation at break decreased from 68.0 to 44.0%. Solubility in water decreased from 35 to 23%, and heat seal strength increased from 375 to 580N/m. Also incorporation of clay nanoparticles in the structure of biopolymer decreased permeability of the gaseous molecules. In summary, addition of halloysite nanoclay, improve the barrier and mechanical properties of potato starch films and this bionanocomposites have high potential to be used for food packaging purposes. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Development of naturally activated edible films with antioxidant properties prepared from red seaweed Porphyra columbina biopolymers.

    PubMed

    Cian, Raúl E; Salgado, Pablo R; Drago, Silvina R; González, Rolando J; Mauri, Adriana N

    2014-03-01

    The aim of this work was to study the physicochemical and antioxidant properties of phycobiliproteins-phycocolloids-based films, obtained from mixtures of two aqueous fractions extracted from Porphyra columbina red seaweed, one enriched in phycocolloids (PcF) and the other in phycobiliproteins (PF). Films with different ratios of PF:PcF (0, 25, 50, 75, 100% [w/w]) and without plasticizer addition were prepared by casting. PcF films had excellent mechanical properties (tensile strength ∼50MPa, elongation at break ∼3% and an elastic modulus ∼17.5MPa). The addition of PF to formulations exerted a plasticizing effect on the PcF matrix, which was manifested in moisture content, water solubility and mechanical properties of the resulting films but not in its water vapour permeability. The antioxidant capacity (TEAC) of the PcF films was significantly increased by the addition of PF and a direct relationship between TEAC and the total phenolic compounds (r(2)=0.9998) and R-phycoerythrin (r(2)=0.9942) was observed.

  14. Structural and optical properties of ZnO:Al thin films prepared by RF magnetron sputtering

    NASA Astrophysics Data System (ADS)

    Gao, Yanqing; Ma, Jianhua; Huang, Zhiming; Hou, Yun; Wu, Jing; Chu, Junhao

    2009-07-01

    ZnO:Al (AZO) films have potential applications in ultraviolet detecting devices. The structural and optical properties of the AZO films are presented. Highly c axis oriented wurtzite phase AZO films are prepared on quartz substrate by rf sputtering method. The optical constants and the thickness of the AZO films are determined by fitting the measured transmission spectra with Tauc-Lorentz (TL) model. The refractive index n increases as the photon energy increases, and reaches the maximum of 2.50 at 3.66 eV, beyond which the refractive index n decreases with further increasing of photon energy. The peak of the refractive index n corresponds to the optical band gap of the AZO films, which is associated with interband transition between the valence and conduction bands. The extinction coefficient k also increases with the enhancement of the photon energy, and a strong absorption peak with maximum of 1.10 is prominent. The absorption peak due to an electronic transition accords with the peak transition energy E0 (3.79 eV) is obtained by TL model. The energy E0 of this model corresponds to the Penn gap, where the strong absorption of the material took place. By fitting the absorption coefficient, the optical band gap 3.62 eV of the film is evaluated. Based on the Tauc's power law, the optical band gap of the films is proved as a direct interband transition between the valence and conduction bands. This enhanced band gap compared with ZnO (3.37 eV) correlates to the Burstein-Moss band filling effect due to Al doping.

  15. Preparation of high-oriented molybdenum thin films using DC reactive magnetronsputtering

    NASA Astrophysics Data System (ADS)

    Shang, Zhengguo; Li, Dongling; Yin, She; Wang, Shengqiang

    2017-03-01

    Since molybdenum (Mo) thin film has been used widely recently, it attracts plenty of attention, like it is a good candidate of back contact material for CuIn1‑xGaxSe2‑ySy (CIGSeS) solar cells development; thanks to its more conductive and higher adhesive property. Besides, molybdenum thin film is an ideal material for aluminum nitride (AlN) thin film preparation and attributes to the tiny (‑1.0%) lattice mismatch between Mo and AlN. As we know that the quality of Mo thin film is mainly dependent on process conditions, it brings a practical significance to study the influence of process parameters on Mo thin film properties. In this work, various sputtering conditions are employed to explore the feasibility of depositing a layer of molybdenum film with good quality by DC reactive magnetron sputtering. The influence of process parameters such as power, gas flow, substrate temperature and process time on the crystallinity and crystal orientation of Mo thin films is investigated. X-ray diffraction (XRD) measurements and atomic force microscope (AFM) are used to characterize the properties and surface roughness, respectively. According to comparative analysis on the results, process parameters are optimized. The full width at half maximum (FWHM) of the rocking curves of the (110) Mo is decreased to 2.7∘, and the (110) Mo peaks reached 1.2 × 105 counts. The grain size and the surface roughness have been measured as 20 Å and 3.8 nm, respectively, at 200∘C.

  16. Preparation of an agar-silver nanoparticles (A-AgNp) film for increasing the shelf-life of fruits.

    PubMed

    Gudadhe, Janhavi A; Yadav, Alka; Gade, Aniket; Marcato, Priscyla D; Durán, Nelson; Rai, Mahendra

    2014-12-01

    Preparation of protective coating possessing antimicrobial properties is present day need as they increase the shelf life of fruits and vegetables. In the present study, preparation of agar-silver nanoparticle film for increasing the shelf life of fruits is reported. Silver nanoparticles (Ag-NPs) biosynthesised using an extract of Ocimum sanctum leaves, were mixed with agar-agar to prepare an agar-silver nanoparticles (A-AgNp) film. This film was surface-coated over the fruits, Citrus aurantifolium (Thornless lime) and Pyrus malus (Apple), and evaluated for the determination of antimicrobial activity of A-AgNp films using disc diffusion method, weight loss and shelf life of fruits. This study demonstrates that these A-AgNp films possess antimicrobial activity and also increase the shelf life of fruits.

  17. Preparation of Nickel-Aluminum-Containing Layered Double Hydroxide Films by Secondary (Seeded) Growth Method and Their Electrochemical Properties.

    PubMed

    Zhang, Fazhi; Guo, Li; Xu, Sailong; Zhang, Rong

    2015-06-23

    Thin films of nickel-aluminum-containing layered double hydroxide (NiAl-LDH) have been prepared on nickel foil and nickel foam substrates by secondary (seeded) growth of NiAl-LDH seed layer. The preparation procedure consists of deposition of LDH seeds from a colloidal suspension on the substrate by dip coating, followed by hydrothermal treatment of the nanocrystals to form the LDH film. The secondary grown film is found to provide a higher crystallinity and more uniform composition of metal cations in the film layer than the in situ grown film on seed-free substrate under identical hydrothermal conditions. A systematic investigation of the film evolution process reveals that the crystallite growth rate is relatively fast for the secondary grown film because of the presence of LDH nanocrystal seeds. Electrochemical performance of the resulting NiAl-LDH films as positive electrode material was further assessed as an example of their practical applications. The secondary grown film electrode delivers improved recharge-discharge capacity and cycling stability compared with that of the in situ grown film, which can be explained by the existence of a unique microstructure of the former. Our findings show an example for the effective fabrication of LDH film with controllable microstructure and enhanced application performance through a secondary (seeded) growth procedure.

  18. Preparation and evaluation of biodegradable films containing the potent osteogenic compound BFB0261 for localized delivery.

    PubMed

    Umeki, Nobuo; Sato, Takayuki; Harada, Masahiro; Takeda, Junko; Saito, Shuji; Iwao, Yasunori; Itai, Shigeru

    2011-02-14

    To achieve sustained release of 3-ethyl-4-(4-methylisoxazol-5-yl)-5-(methylthio) thiophene-2-carboxamide (BFB0261), a new potent osteogenic compound for treating bone disorders, we prepared film formulations containing BFB0261 and the following newly synthesized biodegradable polymers by a solvent casting technique: poly(D,L-lactic acid) (PLA), poly(D,L-lactic acid-co-glycolic acid) (PLGA), poly(D,L-lactic acid)-block-poly(ethylene glycol) (PLA-PEG), and poly(D,L-lactic acid-co-trimethylene carbonate) (PLA-TMC) polymers or copolymers. Powder X-ray diffractometry (PXRD), differential thermal analysis (DTA), scanning electron microscopy (SEM), and tensile testing were performed to examine the physicochemical properties of these films. Almost all the films exhibited a smooth and homogeneous surface, as observed by SEM. In addition, PXRD and DTA revealed that BFB0261 existed in an amorphous state in the films. The in vitro release of BFB0261 from PLA100 (M(w): 251 kDa), PLAPEG9604H (PLA/PEG ratio: 96:4; M(w): 181 kDa), PLAPEG8515H (PLA/PEG ratio: 85:15; M(w): 51.5 kDa), or PLAPEG8020 (PLA/PEG ratio: 80:20; M(w): 33.7 kDa) films followed zero-order kinetics with slow release up to 12 weeks following incubation. Although release of BFB0261 from PLA-TMC films followed first-order kinetics, sustained release of BFB0261 for 12 weeks was still observed for PLATMC8416 (PLA/TMC ratio: 84:16; M(w): 170 kDa) films. Furthermore, when the BFB0261-loaded films constructed from various polymers were implanted subcutaneously on rat backs, the PLAPEG8515H and PLATMC8416 films were capable of achieving sustained release of BFB0261 at the administrated site for 12 weeks. Therefore, the present data indicate that films constructed from PLAPEG8515H or PLATMC8416 may be applicable to bone or tissue engineering. Copyright © 2010 Elsevier B.V. All rights reserved.

  19. In-Situ Preparation of Ytterbium-Barium - Superconducting Thin Films Using Pure Ozone Vapor Oxidation

    NASA Astrophysics Data System (ADS)

    Berkley, Dale Dane

    A new process for preparing thin films of the YBa_2Cu_3O _{rm 7-x} high transition temperature superconducting oxide completely in-situ, without the need for a post-evaporation anneal has been developed. This work is a significant advancement in the effort to achieve a fully mature, high quality thin film-making process for scientific and technical applications. A pure ozone vapor, derived from the distilled liquid, is used to oxidize the co-evaporated metallic constituents during deposition to nucleate the superconducting phase in the vacuum chamber. Films exhibiting zero resistance transition temperatures at 85 K have been grown on strontium titanate substrates using a substrate temperature of 700 ^circC. Background evaporation pressures of 2 x 10^{-7}Torr are employed during film growth. Films prepared using this process contain primarily mixed a- and c-axis oriented grains which, as evidenced by Transmission Electron Microscopy, exhibit a high degree of epitaxial order with the substrate. Processing at lower substrate temperatures results in a depression of T _{rm c} consistent with the behavior observed for other in-situ techniques. It is unclear at this time whether this depression can be attributed to an oxygen deficiency or an expanded c-axis lattice parameter which is always associated with lower temperature processing. Measurements of the critical current of a prototype YBa_2Cu_3O _{rm 7-x}/Au/Pb proximity tunneling junction prepared in-situ using the ozone process do not exhibit the expected magnetic field and temperature dependence. This observation may be the result of a poorly defined tunneling geometry subject to the vagaries of edge effects or filamentary electrical shorts through the normal metal layer. Important implications for the investigation of an isotope effect in the high T_{rm c} superconductors is made possible by the development of the ozone technique. By distilling the ^{18}O gas into a "heavy ozone," thin films can be efficiently

  20. Impurity-doped ZnO Thin Films Prepared by Physical Deposition Methods Appropriate for Transparent Electrode Applications in Thin-film Solar Cells

    NASA Astrophysics Data System (ADS)

    Minami, Tadatsugu; Miyata, Toshihiro; Nomoto, Jun-ichi

    2012-04-01

    This paper describes the development of transparent conducting impurity-doped ZnO thin films that would be appropriate for applications as transparent electrodes in thin-film solar cells. Transparent conducting Al-, B- and Ga-doped ZnO (AZO, BZO and GZO) thin films were prepared in a thickness range from 500 to 2000 nm on glass substrates at 200°C using various physical deposition methods: BZO films with vacuum arc plasma evaporation, AZO and GZO films with different types of magnetron sputtering depositions (MSDs) and all films with pulsed laser deposition (PLD). The suitability and stability of the electrical properties and, in addition, the suitability of the light scattering characteristics and surface texture formation were investigated in the prepared thin films. In particular, the suitability and stability evaluation was focused on the use of AZO, BZO and GZO thin films prepared by doping each impurity at an appropriate content to attain the lowest resistivity. The higher Hall mobility obtained in impurity-doped ZnO thin films with a resistivity on the order of 10-4 Ωcm was related more to the content, i.e., the obtained carrier concentration, rather than the kind of impurity doped into the films. The stability of resistivity of the BZO thin films in long-term moisture-resistance tests (in air at 85% relative humidity and 85°C) was found to be lower than that of the AZO and GZO thin films. The surface texture formation was carried out by wet-chemical etching (in a 0.1% HCl solution at 25°C) conducted either before or after being heat-treated either with rapid thermal annealing (RTA) or without RTA. The suitability of the light scattering characteristics and the surface texture formation obtainable by wet-chemical etching (for use in transparent electrode applications) was considerably dependent on the deposition method used as well as whether the wet-chemical etching was conducted with or without RTA. A significant improvement of both transmittance and