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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 article, poly(3hydroxybutyrate-co-3-hydroxyvalerate) (PHBV)/bamboo pulp fiber (BPF) composites were prepared by melt compounding and injection molding.
Abstract: In this study, poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV)/bamboo pulp fiber (BPF) composites were prepared by melt compounding and injection molding. The crystallization ability, tensile strength and modulus, flexural strength and modulus, and impact strength were found substantially increased by the addition of BPF. Tensile and flexural elongations were also moderately increased at low fiber contents (<20%). BPF demonstrated not only higher strength and modulus, but also higher failure strain than the PHBV8 matrix. Boron nitride (BN) was also investigated as a nucleation agent for PHBV8 and maleic anhydride grafted PHBV8 (MA-PHBV8) as a compatibilizer for the composite system. BN was found to increase the overall properties of the neat polymer and the composites due to refined crystalline structures. MA-PHBV8 improved polymer/fiber interactions and therefore resulted in increased strength and modulus. However, the toughness of the composites was substantially reduced due to the hindrance to fiber pullout, a major energy dissipation source during the composite deformation.

85 citations

Journal ArticleDOI
TL;DR: The role of commonly used binders in the moisture-induced hardness increase in compressed tablets containing lactose as a major excipient was studied and it is suggested that this hardness increase is related linearly to the amount of moisture loss from the tablets after compression.

84 citations

Journal ArticleDOI
TL;DR: In this paper, the authors reported the synthesis of a high-performance microwave absorbing material using a simple, cost-effective and scalable method by encapsulating barium strontium titanate (BST) and expanded graphite (EG) in a polyaniline (PANI) matrix.
Abstract: The present paper reports the synthesis of a high-performance microwave absorbing material using a simple, cost-effective and scalable method by encapsulating barium strontium titanate (BST) and expanded graphite (EG) in a polyaniline (PANI) matrix. One of the formulations (higher content of BST) shows shielding effectiveness due to absorption of more than 50 dB (>99.9999% attenuation) with minimum reflection loss (≤1 dB) in the Ku-band (12.4–18 GHz) frequency range. Another formulation (higher content of EG) shows a total shielding effectiveness of more than 81 dB with a reflection loss of 10 dB. In order to probe the relationship between the observed shielding response and the electromagnetic attributes, dielectric and permeability parameters have been calculated from the measured scattering parameters (S11, S22, S12, S21) using the Nicolson–Ross–Weir algorithm. The synthesised formulations were characterized thoroughly using XRD, FTIR, TGA, UV, Raman spectroscopy, SEM and HRTEM.

84 citations

Journal ArticleDOI
TL;DR: In this article, model gelatin/montmorillonite (Ge/MMt) composites were obtained for a variety of unmodified clay concentrations and in the absence of additives, with the main goal of evaluating the effect of the morphologies developed on the composites thermal stability.
Abstract: Model gelatin/montmorillonite (Ge/MMt) composites were obtained for a variety of unmodified clay concentrations and in the absence of additives, with the main goal of evaluating the effect of the morphologies developed on the composites thermal stability.

83 citations

Journal ArticleDOI
TL;DR: In this article, two different biodegradable polyesters [polycaprolactone (PCL) and poly(3-hydroxybutyrate-co-valerate) (PHBV)] were blended with a maize starch that had high amylose content through the use of different reactive approaches.
Abstract: Two different biodegradable polyesters [polycaprolactone (PCL) and poly(3-hydroxybutyrate-co-valerate) (PHBV)] were blended with a maize starch that had high amylose content through the use different reactive approaches. The compatibilization of both systems was obtained. PCL/starch composites were obtained by the addition of a third reactive component that was able to act as a coupling agent, and the reactive interface of PHBV/starch composites was improved during blending with an organic peroxide. Thermal, morphological, and mechanical characterization showed that the compatibilized composite materials had better final proprieties than neat materials or composites prepared without compatibilization. Finally, the degradation of all prepared materials by a compost simulation test was investigated. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 1432–1442, 2002

83 citations