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Book ChapterDOI

Biopolymer Composites With High Dielectric Performance: Interface Engineering

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.
Citations
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Journal Article
TL;DR: In this article, Boron nitride nanotubes (BNNT)/polyvinyl alcohol (PVA) composite fibers were fabricated via electrospinning so that all BNNTs became aligned in the fiber casting direction.
Abstract: Boron nitride nanotube (BNNT)/polyvinyl alcohol (PVA) composite fibers (<5 vol % BNNTs) were fabricated via electrospinning so that all BNNTs became aligned in the fiber casting direction. A several-fibers-thick ensemble of parallel-arranged contacting fibers made a single polymer sheet. Numerous sheets were then stacked in different ways with respect to the BNNT orientation (all fibers in adjacent sheets were either parallel or alternately rotated 90°) to make multilayer films that were finally hot-pressed. Various BNNT textures were reflected by the corresponding differences in the measured thermal conductivities of the resultant films due to anisotropy of thermal transport in the nanotubes. The highest values (0.54 W/mK) were obtained along the long axes of aligned BNNTs. Somewhat lower values (0.38 W/mK) were documented in films with alternately stacked fibers/tubes. The theoretical thermal conductivity values were estimated using the Nielsen’s model. These show good match with the experimental data. ...

162 citations

Journal ArticleDOI
TL;DR: In this paper, the potential and market stability of gelatin has been discussed and its recent studies are summarised in this paper, focusing on assessing the general utilities of the various sources of collagen as gelatin derivatives.

120 citations

Journal ArticleDOI
TL;DR: In this article, the authors summarized the recent progress in polymer electrolytes for flexible ZIBs, especially hydrogel electrolytes, including their synthesis and characterization, and provided an insight from lab research to commercialization, relevant challenges, device configurations, and life cycle analysis.
Abstract: Owing to the development of aqueous rechargeable zinc-ion batteries (ZIBs), flexible ZIBs are deemed as potential candidates to power wearable electronics. ZIBs with solid-state polymer electrolytes can not only maintain additional load-bearing properties, but exhibit enhanced electrochemical properties by preventing dendrite formation and inhibiting cathode dissolution. Substantial efforts have been applied to polymer electrolytes by developing solid polymer electrolytes, hydrogel polymer electrolytes, and hybrid polymer electrolytes; however, the research of polymer electrolytes for ZIBs is still immature. Herein, the recent progress in polymer electrolytes is summarized by category for flexible ZIBs, especially hydrogel electrolytes, including their synthesis and characterization. Aiming to provide an insight from lab research to commercialization, the relevant challenges, device configurations, and life cycle analysis are consolidated. As flexible batteries, the majority of polymer electrolytes exploited so far only emphasizes the electrochemical performance but the mechanical behavior and interactions with the electrode materials have hardly been considered. Hence, strategies of combining softness and strength and the integration with electrodes are discussed for flexible ZIBs. A ranking index, combining both electrochemical and mechanical properties, is introduced. Future research directions are also covered to guide research toward the commercialization of flexible ZIBs.

119 citations

Journal ArticleDOI
TL;DR: A systematic review methodology based on the application of this novel technology in the field of drug delivery along with the manufacturing of polypills with varied release profiles and geometries is carried out.

72 citations

References
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Journal ArticleDOI
TL;DR: In this paper, the dispersion of pyrrole within aqueous polyvinyl alcohol (PVA) solution gives rise to a nanodispersion with unique stability and monodispersity.
Abstract: Chemical polymerization of pyrrole within aqueous polyvinyl alcohol (PVA) solution gives rise to a nanodispersion with unique stability and monodispersity. The nanodispersion has shown uniform distribution of perfectly spherical ∼110 nm polypyrrole particles (from transmission electron microscopy and dynamic light scattering) with high doping level (from UV-Vis analysis) and sufficient electrical conductivity (10 ―3 S/cm). The dispersion with optimum stability and conductivity was subjected to viscoelastic studies. The viscosity of the system was adjusted by dilution with water and shear thinning (under steady shear) was generally observed. Dynamic mechanical studies have shown that the dispersion behaves like a semidiluted polymeric solution that roughly follows the Zimm model of viscoelasticity. This behavior accounts for its unique stability and miscibility with water at any proportion without precipitation. On drying or leaving the sample for 7 days, Fe 3+ induced partial crosslinking of PVA chains takes place via ―OH groups, although complete gelling does not occur. The dispersion forms flexible and uniform films on glass and metal surfaces that does not dissolve after complete drying; this observation combined with shear thinning encourages its application as ink or paint.

14 citations

Journal ArticleDOI
TL;DR: Stannic oxide (SnO 2 ) nanoparticles have been suspended in polyvinyl alcohol (PVA) matrix in different PVA:snO 2 molar ratios ranging from 1:1 to 1:5 using simple chemical route as mentioned in this paper.

14 citations

Journal ArticleDOI
TL;DR: An effective blood coagulant and wound healing agent, which on its topical application on ruptured skin would help in instant coagulation of blood and ongoing healing of wound is made.
Abstract: The aim of this study is to make an effective blood coagulant and wound healing agent, which on its topical application on ruptured skin would help in instant coagulation of blood and ongoing healing of wound. The hydrogel has been prepared by mixing 28% w/v gelatin and 21% w/v PVA in distilled water, and heated to 40°C followed by addition of a blood coagulant at a lower temperature. Beeswax, alcohol, liquid paraffin, and adrenochrome were mixed, triturated, and heated accordingly to prepare adrenochrome ointment. Polyvinyl alcohol and glycerin were mixed and heated and the drug was added at a lower temperature, and stored at 4–5°C to form adrenochrome gel. Gelatin alone has cell adhesion property. Adrenochrome is a blood coagulant. Therefore, gelatin with adrenochrome in hydrogel has a synergistic effect in wound healing. To evaluate the efficacy of these three different formulations, incisions were made on the backs of three mice and simultaneously adrenochrome containing hydrogel patch, gel, ...

13 citations

Journal ArticleDOI
TL;DR: In this paper, an investigation was made to determine the influence of furnace temperature, concentration of oxygen in the gas flow and sample mass (2.5 mg) on the decomposition time of polyethylene and chlorinated polyethylenes.

12 citations

01 Jan 2015
TL;DR: In this article, a sensor for detection of vapors of volatile organic compounds (VOCs) such as ethanol, isopropyl alcohol and acetone is tested using NiO nanoparticles.
Abstract: In the present study, NiO nanoparticles with average particle size of 35 nm were successfully prepared by solvothermal method. Thecrystal microstructure,composition, morphologyand particle size distribution of product was analyzed by using X-ray diffraction (XRD),Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and EDAX. A sensor for detection of vapors of volatile organic compounds (VOCs) such as ethanol, isopropyl alcohol and acetone is tested using NiO nanoparticles. One of the key features of the sensor is the use of nanostructured NiO material which has been synthesized using a novel low cost process. Considerable reduction in the operating temperature of the sensor has been achieved by using nanostructured NiO material. The maximum sensitivity of sensor was observed for Ethanol.

7 citations