Papers by Keyword: Film

Abstract: Based on the selective adsorption property of the imidazolium-type hyperbranched polymeric ionic liquid (hb-PIm⁺PF₆^-) towards anionic dyes, it was incorporated into poly(vinylidene fluoride) (PVDF) matrix to modify PVDF film. The composite hb-PIm⁺PF₆^-/PVDF films were prepared via non-solvent-induced phase inversion method. The obtained composite films were characterized by attenuated total reflectance-Fourier transform infrared spectroscopy, scanning electron microscopy, and contact angle goniometry. Using bromophenol blue (BPB, an acidic dye) as the model molecule, the dynamic and static adsorption properties of the hb-PIm⁺PF₆^-/PVDF films were investigated, respectively. It is significant that the hb-PIm⁺PF₆^-/PVDF composite films could efficiently remove BPB from water under dynamic condition.

Abstract: Bacterial cellulose (BC) is the cellulose which is produced by specific bacteria such as Acetobacter xylinum, Agrobacterium, Gluconacetobacter, Rhizobium, Achromobacter, Alcaligenes, Aerobacter, Azotobacter, Salmonella, Esherichia, and Sarcina. Surface modification of bacterial cellulose (BC) by coating with synthetic biodegradable polyester on it was reported. BC films were coated with the polymer at different concentrations in order to improve the surface structure of BC. Tear and burst indices of the BC film were increased with such modification.

Abstract: Esterified rice straw cellulose was synthesized by the reaction of cellulose with lauroyl chloride in the presence of toluene medium. Microwave heating was used to accelerate the esterification of cellulose. The optimum condition for esterification was investigated in term of microwave power and reaction time. Solubility of modified cellulose was characterized. The cellulose films were prepared by solvent casting method and mechanical properties of cellulose films were tested. The result shows that the best condition for cellulose esterification was 100 W of microwave power and 15 minute of esterification time. Percentage of weight increase of esterified cellulose at this condition was 143.83 %. Modified cellulose can be dissolved in organic solvent such as toluene, dichloromethane and chloroform. Tensile properties of cellulose films were examined. Tensile strength, Young’s modulus and % elongation at break of rice straw cellulose ester film were 2.33 MPa, 56.63 MPa and 4.21 %, respectively.

Abstract: The polystyrene (PS) has a variety of applications. Many mechanisms have been proposed for the degradation of the polymer, but a consistent mechanism does not exist yet in the literature due to the complexity of the kinetics and formation of photoproducts that depend on various conditions photodegradation. The aim of this study was to investigate the kinetic behavior of the photodegradation of PS films photosensitized by thioxanthone (TX) under UV, Vis and xenon radiation. Changes in chemical structure caused by photo-oxidation in the films were verified by FT-IR. The photodegradation of polystyrene films sensitized by thioxanthone showed greater efficiency in the formation of carbonyl group under Vis radiation and xenon when compared to pure PS. However, in the ultraviolet films system PS and PS / TX exhibited similar kinetic behavior.

Abstract: This research aimed to study the compatibility and properties of deproteinized natural rubber latex (DNRL)/gelatinized starch blended films for use as transdermal patches. Various starches were previously gelatinized by heat treatment. Then, the DNRL/gelatinized starch blended films were prepared by simple mixing of DNRL with gelatinized starch and then drying at 50°C. The various parameters such as types (potato, sago, bean, corn, tapioca, rice and glutinous starches), amounts (5, 10, 15 and 20 part per hundred of rubber (phr)) and concentrations of gelatinized starch pastes (5, 10, 20 and 50%) were evaluated. It was found that all starch types could be blended as a homogeneous mixture with DNRL only in 5 phr. Bean starch also provided the good mixture in 10 and 15 phr. Rice and corn starches in the concentrations up to 20 phr could also be blended. Higher concentration of gelatinized starch pastes obtained the higher viscous liquids that were difficult to blend as a homogeneous mixture with DNRL, and provided inhomogeneous blended films. The dried films of all homogeneous DNRL/gelatinized starch mixtures were slightly yellowish transparent with good physical appearances. The tensile strength, swelling and erosion of these blended films increased when increasing amounts of gelatinized starch, but their elasticities were not different comparing to that of DNRL film itself. However, their strengths should be further improved by adding some plasticizers. Some drugs would be further loaded in these homogeneous film formulations for transdermal delivery.

Abstract: A catalyst-coated membrane (CCM) with structure and material gradient variation was deposited layer-by-layer (LbL) using electrohydrodynamic atomization (EHDA) deposition. This CCM contained 7 layers which is C cathode diffusion layer, Pt/C-C cathode transition layer, Pt/C cathode catalyst layer, Nafion membrane, Pt-Ru/C anode catalyst layer, Pt-Ru/C-C anode transition layer and C anode diffusion layer. The cathode and anode side were named as cathode and anode catalyst-diffusion layers, respectively. It was observed that the cathode and anode catalyst-diffusion layers presented the dendritic structure. Within the cathode and anode catalyst-diffusion layers, the Pt/C-C and Pt-Ru/C-C transition layer was more porous compared to the C layer, Pt/C layer and Pt-Ru/C layer. It was also shown that the EHDA LbL deposited CCM still presented close-packed structure after life test.

Abstract: Zirconium silicate thin film was prepared via a novel non-hydrolytic sol-gel (NHSG) process at low temperature using zirconium tetrachloride (ZrCl₄) and tetraethoxysilane (TEOS) as precursors. The phase composition and the microstructure of samples were characterized by X-ray diffraction analysis (XRD) and scanning electron microscopy (SEM), respectively. The results demonstrate that pure ZrSiO₄ film can be synthesized by using ethanol and isopropanol as solvent rather than dimethyl formamide (DMF) and dimethyl nylon acid (DBE) which cause impurity ZrO₂. However, only ethanol can achieved smooth and dense ZrSiO₄ film. The viscosity results suggest that the sol with ethanol has great stability. With a pulling rate of 1.0 mm s^-1, a high quality ZrSiO₄ film was prepared after drying at 50 ^oC for 2 h and calcination at 850 °C with a heating rate of 1.0 °C min^-1.

Abstract: Palladium nanograins placed in carbonaceous matrix shows many interesting properties connected to ability of hydrogen adsorption/absorption. Carbonaceous-palladium (C-Pd) films based on these materials change their structure and form, electrical conductivity, capacitance as well as optical absorption, transmission and reflection properties. These effects are connected to an incorporation of hydrogen atoms into palladium lattice [1], what change not only lattice constant [2] but also electric [3] and optical [4] properties of resulting material.

Abstract: The scanning acoustic microscope is used to detect the properties of films. The ultrasonic wave propagates in the films with thickness h, acoustic impedance Z₂ between medium with acoustic impedance Z₁. The echoes from upper and lower interfaces overlap and interfere. The echoes are transformed by FFT. The interference phenomena are observed in amplitude spectrum of echoes. The spectrum has periodic extreme values at f_n, f_n=nc/2h. When thickness h is known, sound velocity c₂ of film can be calculated. According to the principle, the properties of films such as thickness, acoustic impendence and elastic modulus are evaluated by scanning acoustic microscopy. The experimental results are good accorded with the actual properties of specimens.

Abstract: The purpose of this study was to evaluate the effect of modified coconut oil (MCO) on elasticity change of films prepared from shellac. The MCO was added into shellac solution and then cast to thin film. The film containing MCO from 0-30% w/w was then comparatively evaluated. The result indicated that MCO had an direct effect on mechanical properties of films. The percentage elongation was increased while the tensile strength was decreased, as increasing percentage of MCO, suggesting the reduced brittleness of film. The FTIR peak assigned to O-H and C-O stretching was also shift after incorporation of MCO. Therefore, the plasticization of shellac film might due to the interaction between hydroxyl group of glycerides in MCO and shellac molecules.