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Films Decreased (film + decreased)
Selected AbstractsThermal stability of porous it -PMMA thin film obtained by the extraction of st -PMAA from it -PMMA/st -PMAA stereocomplex with layer-by-layer assembly on a substrateJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 15 2010Hiroharu Ajiro Abstract The functionality of porous isotactic (it) poly(methyl methacrylate) (PMMA) thin films, which were previously developed by the selective extraction of syndiotactic (st) poly(methacrylic acid) (PMAA) from the it -PMMA/st -PMAA stereocomplex thin film on a substrate using the layer-by-layer assembly method was investigated after thermal treatment (70, 80, and 90 °C) in water for 4 h. Quartz crystal microbalance analysis and infrared spectra measurements revealed that the st -PMAA incorporation ability of the porous it -PMMA thin film decreased in order at 80 and 90 °C, while there was no decrease observed at 70 °C. X-ray diffraction analysis also supported the thermal stability of the porosity at 70 °C, whereas two it -PMMA crystalline peaks (2, = 9° and 14°) were generated during heating at 90 °C. The loss of the functionality of the it -PMMA thin film was thus shown to be due to crystallization, which was caused by the increase in polymer-chain mobility during the heating process. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 3265,3270, 2010 [source] The effect of oxygen remote plasma treatment on ZnO TFTs fabricated by atomic layer depositionPHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 8 2010Seungjun Lee Abstract We deposited ZnO thin films by atomic layer deposition (ALD) and then investigated the chemical and electrical characteristics after plasma treatment. The chemical bonding states were examined by X-ray photoelectron spectroscopy (XPS). The XPS spectra of O 1s showed that the intensity of oxygen deficient regions of the ZnO film decreased from 27.6 to 19.4%, while the intensity of the oxygen bound on the surface of the ZnO film increased from 15.0 to 21.9% as plasma exposure times increased. The ZnO film exhibited a decrease in carrier concentration from 4.9,×,1015 to 1.2,×,1014,cm,3 and an increase in resistivity from 1.2,×,102 to 9.8,×,103,,,cm as the plasma exposure times increased. To verify the changes in the chemical and electrical properties of the ZnO films caused by the oxygen remote plasma treatment, ZnO thin film transistors were fabricated and their electrical properties were investigated. We found that the Ion/Ioff ratio increased from 7.3,×,104 to 8.6,×,106, the subthreshold swings improved from 1.67 to 0.45,V/decade, and the saturation mobility (µsat) decreased from 1.63 to 0.72,cm2/V,s as plasma exposure times were increased. [source] EFFECT OF GLYCEROL ON PHYSICAL PROPERTIES OF CASSAVA STARCH FILMSJOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 2010P. BERGO ABSTRACT In this work, the effect of glycerol on the physical properties of edible films were identified by X-ray diffraction (XRD), differential scanning calorimetry (DSC), infrared (FTIR) and microwave spectroscopy. According to XRD diffractograms, films with 0 and 15% glycerol displayed an amorphous character, and a tendency to semicrystallization, for films with 30% and 45% glycerol. From DSC thermograms, the glass transition (Tg) of the films decreased with glycerol content. However, two Tgs were observed for samples with 30% and 45% glycerol, due to a phase separation. The intensity and positions of the peaks in FTIR fingerprint region presented slight variations due to new interactions arising between glycerol and biopolymer. Microwave measurements were sensitive to moisture content in the films, due to hydrophilic nature of the glycerol. The effect of plasticizer plays, then, an important rule on the physical and functional properties of these films, for applications in food technology. PRACTICAL APPLICATIONS Edible and/or biodegradable films are thin materials used mainly in food recovering, food packaging and other applications, in substitution of the films obtained by synthetic ways. In view of these applications, these films must satisfy some of the exigencies in order to increase the food shelf-life, or in other words, they must be flexible, transparent, resistant to some gases such as oxygen, as well as resistant to water vapor. The addition of plasticizers alters the functional properties of the films. Thus, the physical characterization of these films becomes fundamental in order to increase their potential use in industry. [source] Adsorption and rheological properties of biopolymers at the air-water interfaceAICHE JOURNAL, Issue 7 2006Rosa Baeza Abstract Dynamics of adsorption and viscoelasticity of biopolymers (,-lactoglobulin (,-lg) + polysaccharides (PS)) at 20 °C and pH 7 have been studied. Protein concentration in the bulk phase was 0.1 wt %, and the concentration of polysaccharides (xanthan gum, ,-carrageenan, and propylenglicol alginate with different degrees of esterification and viscosity) was varied from 0.1% to 0.5 wt %. The results reveal a significant effect of surface-active and non surface-active polysaccharides on the dynamics of the formation and viscoelasticity of adsorbed films at the air-water interface. The rate of diffusion of the biopolymers increased in the mixed systems, but the effect was more significant at the highest concentration of polysaccharide (0.5 wt %). The rate of rearrangement of the adsorbed films decreased in the presence of polysaccharides as compared to the protein film. Competitive adsorption, complexation and limited thermodynamic incompatibility between ,-lactoglobulin and polysaccharide would explain the observed effects. © 2006 American Institute of Chemical Engineers AIChE J, 2006 [source] Novel side-chain liquid-crystalline polyimide for film materialsJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 4 2003Haojun Fan Abstract A novel side-chain liquid-crystalline polyimide (SLCPI) was prepared via copolycondensation from 3,5-diamino-benzonic-4,-biphenyl ester, 4,4,-diamino- biphenyl ether, and 3,3,,4,4,-oxydiphthalic dianhydride. The energy-minimized structure and liquid crystallinity of SLCPI were investigated by molecular modeling, differential scanning calorimetry (DSC), wide-angle X-ray scattering, and polarized optical microscopy, respectively. The results indicated that this polyimide (PI) with side-chain mesogenic units exhibited a nematic NI phase. Because of the in situ self-reinforcement of side-chain mesogenic units, the improved tensile strength and modulus of PI films reached 270% and 300%, respectively. The coefficient of thermal expansion of films decreased by 40%. DSC and thermogravimetric analyses indicated that the phase-transition temperature of SLCPI was above 240 °C, and the 5% weight-loss temperature was above 520 °C. Moreover, copolycondensation of two diamines with dianhydride and incorporation of pendent mesogenic units diminished the regularity and symmetry of main chains; as a result, SLCPI exhibits good film processability. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 554,559, 2003 [source] MgTiO3 and Ba0.60Sr0.40Mg0.15Ti0.85O3 Composite Thin Films with Promising Dielectric Properties for Tunable ApplicationsJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 9 2008Lina Gao Mg2TiO4 -doped Ba0.60Sr0.40Mg0.15Ti0.85O3 (BSTM) thin films with different Mg2TiO4 concentrations were deposited on a polycrystalline alumina substrate via the sol,gel method. With the addition of Mg2TiO4, MgTiO3, MgAl2O4, and BSTM phases were formed in these composite thin films. The dielectric loss of the composite thin films decreased about one order of magnitude and the tunability still remained above 15% at a DC-applied electric field of 80 kV/cm. The dielectric constant decreased from 1040 to 388. The low dielectric constant, high tunability, and figure of merit of these composite thin films can be useful for potential tunable devices. [source] Physical properties of edible films based on cassava starch as affected by the plasticizer concentrationPACKAGING TECHNOLOGY AND SCIENCE, Issue 2 2008P. V. A. Bergo Abstract The aim of this work was to investigate the effect of glycerol contents on physical properties of cassava starch films. The films were prepared from film-forming solutions (FFS) with 2g cassava starch/100g water and 0, 15, 30 and 45g glycerol/100g starch, and were analysed to determine its mechanical properties by tensile tests, the glass-transition temperature (Tg) by differential scanning calorimetry (DSC) and the crystallinity by X-ray diffraction (XRD). The infrared spectra of the films were also recorded. The resistance values of the films decreased, while those of the elasticity increased with an increase in glycerol concentration due to the plasticizer effect of glycerol, which was also observed in DSC curves. The Tg of the films prepared decreased with the glycerol content. However, for samples with 30 and 45g glycerol/100g starch, two Tg curves were observed, probably due to a phase separation phenomenon. According to the XRD diffractograms, the films with 0 and 15gglycerol/100g starch presented an amorphous character, but some tendency to show crystalline peaks were observed for films with 30 and 45g glycerol/100g starch. The results obtained with Fourier transform infrared (FTIR) corroborated these observations. Copyright © 2007 John Wiley & Sons, Ltd. [source] Effects of ozone exposure on the structural, mechanical and barrier properties of select plastic packaging filmsPACKAGING TECHNOLOGY AND SCIENCE, Issue 6 2002Banu F. Ozen Abstract The effects of ozone (O3) gas exposure at various concentrations and treatment times on structural, mechanical and barrier properties of polyethylene and polyamide films were investigated. Changes in the structure of the films were monitored using an FT-IR spectrometer. The results showed that O3 treatment affected polyethylene and polyamide films differently. While O3 treatment caused formation of oxygen-containing functional groups and degradation of polymeric chains in polyethylene films, O3 treatment of polyamide films significantly increased the ,C,N, stretch observed at 1125,cm,1 in the FT-IR spectra. The changes in the mechanical properties of polyethylene films depended on the O3 treatment conditions (temperature and O3 concentration were the most significant), but an increase in tensile strength of polyamide films was observed regardless of the treatment conditions. Permeability to O2 for both types of films decreased with increasing O3 treatment time. Copyright © 2003 John Wiley & Sons, Ltd. [source] Growth of epitaxial garnet film by LPE for application to integrated magneto-optic light switch arraysPHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 8 2004J. H. Park Abstract We investigate the dependence of the properties of garnet films grown by liquid phase epitaxy (LPE) on the procedure and the temperature of growth to tailor magnetic properties of Bi, Gd, Ga:YIG film for application to integrated magneto-optic light switch arrays. Because the yttrium and gallium concentrations of the films decreased slightly and the bismuth, iron concentrations of the films increased slightly with decreases of the growth temperature, the magnetic properties of the garnet film grown by LPE are very sensitive specially to a growth temperature. The decrease of Hsat with decreasing growth temperature indicates that the perpendicular magnetic anisotropy energy of the film decreases. The Bi, Gd, Ga:YIG film grown at around 730 °C have good magnetic properties, i.e., a low value of 4,Ms of 120 G, a low value of saturation field Hsat of 168 Oe, and a low perpendicular magnetic anisotropy for application of the magneto-optic spatial light modulators. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Synthesis and chiroptical properties of liquid crystalline copolymers containing azobenzene chromophoresPOLYMER INTERNATIONAL, Issue 6 2007Zhi Zheng Abstract A series of new liquid crystalline copolymers, poly[((S)-2-methyl-1-butyl methacrylate)- co -(6-(4-(4-cyanophenylazo)phenoxy)hexyl methacrylate)], with different contents of chiral units of 17, 36, 54 and 78 mol% were synthesized. The structures and properties of the copolymers were characterized and evaluated using infrared, 1H NMR and UV spectroscopy, differential scanning calorimetry, gel permeation chromatography and circular dichroism (CD). The CD results suggested that absorptions of azobenzene chromophores were observed in films of copolymer containing 17, 36 or 54 mol% chiral units, but not in the film of copolymer containing 78 mol% chiral units. Also, CD values of the copolymeric films decreased with increasing chiral content. After irradiation with linear polarized light at 442 nm, CD values were changed in all the copolymeric films, and the CD values increased with decreasing chiral content in a nonlinear way, while the photoinduced change of chirality of the copolymers increased in a linear way with decreasing chiral content. The results are discussed in terms of interactions between structures and chiroptical properties. Copyright © 2007 Society of Chemical Industry [source] | |||||||||||||