Biopolymer Composites With High Dielectric Performance: Interface Engineering
01 Jan 2017-pp 27-128
TL;DR: In this article, the preparation and dielectric behavior of various biopolymer composites is presented, including metal nanoparticles and carbon-based nanofillers such as carbon nanotubes, graphene, etc.
Abstract: In recent years, there is a growing interest in studying the dielectric behavior of biopolymer composites due to their potential application as a dielectric material in various electronic devices such as microchips, transformers, and circuit boards. Conducting electroactive polymer composites have also been investigated for various potential applications which include biological, biomedical, flexible electrodes, display devices, biosensors, and cells for tissue engineering. In this chapter, the preparation and dielectric behavior of various biopolymer composites is presented. These biopolymer composites generally consist of nanoscale metal nanoparticles and carbon-based nanofillers such as carbon nanotubes, graphene, graphene oxide (GO), etc., dispersed into the polymer matrix. The physical and chemical properties of these fillers and their interactions with polymers have a significant effect on the microstructure and the final properties of nanocomposites. The biopolymer composites with excellent dielectric properties show great promise as an energy storage dielectric layer in high-performance capacitor applications such as embedded capacitors. This chapter highlights some of the examples of such biopolymer composites; their processing and dielectric behavior will be discussed in detail.
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References
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TL;DR: In this paper, 3D isothermal flow simulations were used to obtain flow patterns in various processing equipment and these flow patterns were further processed for mixing efficiency analysis, and the dynamics of the mixing process was studied numerically by means of tracers and their trajectories in the processing equipment.
Abstract: Flow patterns In various processing equipment were obtained based on 3D isothermal flow simulations. These flow patterns were further processed for mixing efficiency analysis. The dynamics of the mixing process was studied numerically by means of tracers and their trajectories In the processing equipment. Dispersive mixing efficiency was studied in terms of shear stresses and elongational flow components distributions. Distributive mixing efficiency was characterized using length stretch distributions and average values. Features of chaotic flow were also analyzed. The framework developed to analyze mixing efficiency opens the way for an unambiguous evaluation of equipment performance and for process optimization.
25 citations
TL;DR: In this article, the effects of γ irradiation on the mechanical, thermal, structural, and electrical properties of polyacrylonitrile (PAN) were examined, with nonirradiated PAN films serving as control samples.
Abstract: In this study, we examined the effects of γ irradiation on the mechanical, thermal, structural, and electrical properties of polyacrylonitrile (PAN). Irradiation doses of 20, 40, 60, 80, and 100 kGy were used, with nonirradiated PAN films serving as control samples. Microhardness measurements, mechanical tests, Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimetry analysis, color determination, X-ray diffraction, and electrical properties were investigated to evaluate the effects of the irradiation treatments on the PAN films. A fair consistency was observed between the microhardness results. Irradiation caused a significant deterioration in the mechanical properties of the samples. The tensile strength and percentage elongation at break decreased with increasing irradiation dose. Similarly, Young's modulus and toughness also decreased with increasing irradiation dose. The melting and crystallization temperatures decreased, whereas the degree of yellowness increased with increasing irradiation dose. The percentage crystallinity of the PAN film increased with increasing irradiation dose. The FTIR spectra showed that there was a tendency toward a greater effect of γ irradiation on the structure of PAN at higher irradiation doses. The values of the electrical parameters, such as capacitance in parallel, dielectric constant, dielectric loss, resistance in series, resistance in parallel, reactance, and quality factor, increased, whereas the values of capacitance in series, impedance, conductance, susceptance, admittance, and phase angle decreased because of the γ irradiation. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
24 citations
TL;DR: In this article, the effect of different moisture contents on PVA-gelatin films by means of dielectric properties, infrared spectroscopy, microwave response and gravimetric method was investigated.
Abstract: In this work, it was investigated the effect of different moisture contents on PVA-gelatin films by means of dielectric properties, infrared spectroscopy, microwave response and gravimetric method. The films were elaborated from a blend of gelatin and PVA, with 0 and 25 % glycerol. The sorption isotherms were determined by gravimetric methods, at 25 °C. A capacimeter was used for dielectric measurements, and a device called SOLFAN setup was used for microwave measurements. The sorption isotherms were markedly affected by the glycerol content and relative humidity, due to the hygroscopic nature of the films. The dielectric constant and the microwave response signal were also strongly affected by the moisture and glycerol content in the films. Finally, Infrared spectra showed some changes in the amide peak positions, attributed to the modifications in the interactions between the macromolecules. The behaviors obtained in this work were explained on the basis the way the water enters in the film matrix.
23 citations
TL;DR: In this paper, a new and simple method has been applied to measure the dielectric constant of polyvinyl cyanoethylate/barium titanate composites by dispersing the ceramic powders in the polymer of a relatively low value.
21 citations
TL;DR: In this paper, the surface properties of thin layer of polymer blend coated on the cardboard sheet substrate material were measured and properties such as flexibility index, yellowness, and gloss reflectance were also measured.
Abstract: Surface properties of a polymeric coating system have a strong influence on its performance and service life. However, the surface of a polymer coating may have different chemical, physical, and mechanical properties from the bulk. Significant progress has been made during the last three decades in the improvement of coating on materials. It has been established that polymeric blends have great potential in replacing economically many conventional materials because of their high specific strength. It is needed today, constantly, to improve the surface finish of any material for efficiency and shiny appearance in the severity of working environment. In packaging, materials having longer service lives and those are less corrosive are highly used. The effect of polymer based coating on the paper material improves its mechanical properties and flame resistance. Effect of flame retardant polymer coating illuminates the surface of the sheet. Important application of the material sheets will be for corrosion receptivity and humidity resistance of this material will certainly improve. Blends of PMM/PVDF are mainly used to improve piezoelectric properties of PVDF. In the present study we report the measurement of surface properties of thin layer of polymer blend coated on the cardboard sheet substrate material. Polymer blend solutions of PMMA/PVDF was prepared at 90/10 (w/w) proportions in miscible solvent of toluene and DMF. Thin film was prepared on the surface of cardboard by dipping the cardboard material in the solution. Thickness of the dried polymer coated paper sheet was measured to see uniformity of coating and for different concentrations. Surface properties such as flexibility index, yellowness, and gloss reflectance were also measured. The study on these polymer coated paper will help in improving the surface property of paper as well as its use in packaging. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4167–4171, 2006
21 citations