Papers by Keyword: Composite Film

Abstract: Abstract: In this paper, Polyepichlorohyron(PECH)/multi-wall carbon nanotubes(MWCNTs) composite films and PECH/multi-wall carbon nanotubes twolayer film were deposited on interdigitated electrodes by airbrush technology to detect ethanol vapor of various concentrations at room temperature. Thickness and structure of the film were taken into account, so films of different thicknesses and with different structures were prepared respectively. The responses of the sensors to ethanol showed that composite film had a higher response thantwolayer film, and the thick composite film performed better than its counterpart when they were exposed to ethanol vapor.

Abstract: Self-assembled composite films of APTES-GA-APTES were successfully prepared on single-crystal silicon substrates through the cross-linking reaction between glutaraldehyde (GA) and two layers of 3-aminopropyltriethoxysilane (APTES). The optimal time to deposit the GA layer on the APTES monolayer was 3 h, during which most amino groups of APTES reacted with the aldehyde groups of GA to form smooth and uniform APTES-GA composite films. The further deposition of another APTES layer led to the generation of three-layer APTES-GA-APTES composite films. Compared to the APTES self-assembled monolayers, the three-layer films displayed a similar surface morphology but a reduced friction coefficient from 0.23 to 0.15 and an extended wear life from 50 s to 820 s due to the introduction of GA.

Abstract: Magnetic properties and ferromagnetic resonance data of (Co₄₁Fe₃₉B₂₀)_x-(SiO₂)_100-x composite films and multilayer structures composed of these films separated by SiC interlayers have been studied. It has been shown that one of the possible causes responsible for the differences of magnetic properties of composites and multilayer structures can be different shapes of magnetic particles and granules in these materials.

Abstract: In this work a preliminary study on the physical properties and antimicrobial activity of environmentally friendly active films to be produced is presented. Chitosan (CH), which has antimicrobial effect on many food pathogens, was coated as antimicrobial agent into composite poly (lactic acid)/poly (ε-caprolactone)(PLA-PCL) films. Antimicrobial active films based on PLA-PCL were prepared by coating five different chitosan concentrations: 0, 2, 4, 6 and 8 %(w/w). The mechanical characterization, water vapor permeability (WVP), and antimicrobial activity of composite PLA-PCL film coating with chitosan were carried out. The mechanical characterization, water vapor permeability of composite PLA-PCL films coating with chitosan was uninfluenced. Antimicrobial activities of films were tested against Staphylococcus aurous, Escherichia coli, Bacillus subtilis, Listeria, Salmonella. The antimicrobial activity of films were significantly increase with the chitosan concentration. The results of this work suggest that chitosan coated composite PLA-PCL films have a prospectively potential in antimicrobial activity food packaging.

Abstract: The uniform and transparent Zn₂TiO₄ series thin films were successfully deposited on medical glass slide by magnetron sputtering. The influences of the Zn-doped quantity and annealing treatment on films properties were investigated. Film structure, surface morphologies and optical properties were measured with XRD, SEM and UV-VIS transmittance spectroscope. The results show that the Zn-doped quantity and annealing treatment have influence on the absorption edges. The absorption edges of the films can increase 10nm after annealing treatment. The intensity of c-series ZnTiO₃ diffraction peaks is higher, which may be that the grain size is bigger and the crystallization is complete. The annealing treatment not only growing up grain size of composite films, but also the surface films have tiny crack phenomenon.

Abstract: Thymol (TH), which has antimicrobial effect on many food pathogens, was incorporated as antimicrobial agent into composite poly (lactic acid)/poly (trimethylene carbonate)(PLA-PTMC) films. Antimicrobial active films based on PLA-PTMC were prepared by incorporating thymol at five different concentrations: 0, 3, 6, 9 and 12 %(w/w). The mechanical characterization, water vapor permeability (WVP), and antimicrobial activity of all formulations composite film were carried out. A decrease in elastic modulus was obtained for the active composite film compared with neat PLA-PTMC film. The presence of thymol decreased water vapor permeability, with a significant antimicrobial activity. Antimicrobial activities of films were tested against Escherichia coli, Staphylococcus aurous, Listeria, Bacillus subtilis, and Salmonella. Increasing amount of the thymol in the film caused a significant increase in inhibitory zones. These results suggest that thymol incorporated PLA-PTMC films have a prospectively potential in antimicrobial food packaging.

Abstract: The ZnS-ZnO composite film was successfully prepared by sulfidation of the as-electrodeposited ZnO film in the aqueous solution of zinc nitrate and hexamethylenetetramine. The ZnO film was electrodeposited on the substrate of indium-tin oxide (ITO) glass, and then the sodium sulfide solution was used to convert the ZnO film into the ZnS-ZnO composite film. The products were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectrometer (EDS) and UVvisible absorption. The experimental results show that the composite film on ITO glass still retained the morphology of as-electrodeposited ZnO coating, and is composed of ZnS with cubic structure and ZnO with hexagonal structure.

Abstract: PTFE/Nafion (PN) membranes were fabricated for the application of moderate and high temperature proton exchange membrane fuel cells (PEMFCs), respectively. Membrane electrode assemblies (MEAs) were fabricated by PTFE/Nafion membranes with commercially available low and high temperature gas diffusion electrodes (GDEs).The influence of [ZrOCl₂]/[Nafio wt. ratio of Nafion/ZrOCl₂ solution on the membrane morphology of NFZrP and PEMFCs performance was investigated. And the influence of hybridizing silicate into the PN membranes on their direct methanol fuel cell (DMFC) performance and methanol crossover was investigated. Silicate in PN membranes causes reduction both in proton conductivity and methanol crossover of membranes. Due to the low conductivity of PTFE and silicate, PNS had a higher proton resistance than Nafion-112.The effects of introducing sub-μm porous PTFE film and ZrP particles into Nafion membranes on the DMFC performance were investigated. The influence of ZrP hybridizing process into NF membranes on the morphology of NFZrP composite membranes and thus on the DMFC performance was also discussed.

Abstract: The low density polyethylene (LDPE)/ethylene-octene copolymer (POE) blend films and LDPE/POE/inorganic particle composite films were prepared. By means of DSC method, the crystallization capability and the non-isothermal crystallization kinetics of LDPE composite films were investigated, the results show that the addition of DE can reduce the interfacial free energy of the crystal and the active energy of a nucleus, resulting in stable nuclei can be formed at lower supercooling, which makes the polymer crystallized successfully at high temperatures. By selecting data processing method of Mo ZS and modified Jeziorny, the results indicate that the DE play a role of heterogeneous nucleation agent in the process of crystallization and increased the crystalline rate of LDPE.

Abstract: To meet the requirement of microelectronic industry, ceramic/polymer composite films made of CaCu₃Ti₄O₁₂ (CCTO) powder as filler and PVDF copolymer as matrix were prepared by solution casting method. The dielectric properties (DP) and morphology of the films were studied by impedance analyzer and scanning electron microscope (SEM) respectively. The dielectric constant could reach 23.96 and loss 0.1082 when mass fraction of CCTO is 50% at 100 Hz. SEM results show that CCTO particles dispersed well in the PVDF matrix. At last, three composite models were used to predict the dielectric constant of the composite films and it is proved that Yamada model fits the experimental data well.