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.

Biopolymer Composites With High Dielectric Performance: Interface Engineering

The recent surge in graphene research has stimulated interest in the investigation of various two-dimensional (2D) nanomaterials, including 2D boron nitride (BN) nanostructures. Among these, hexagonal boron nitride nanosheets (h-BNNs; also known as white graphene, as their structure is similar to that of graphene) have emerged as potential nanofillers for preparing thermally conductive composites. In this work, hexagonal boron nitride nanoparticles (h-BNNPs) approximately 70 nm in size were incorporated into a polyvinylidene fluoride (PVDF) matrix with different loadings (0–25 wt.%). The PVDF/h-BNNP nanocomposites were prepared by a solution blending technique and characterized using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), polarized optical microscopy (POM) and scanning electron microscopy (SEM). In addition, the thermal conductivity and dielectric properties of the nanocomposites were investigated. The incorporation of h-BNNPs in the PVDF matrix resulted in enhanced thermal conductivity. The highest value, obtained at 25 wt.% h-BNNP loading, was 2.33 W/mK, which was five times that of the neat PVDF (0.41 W/mK). The thermal enhancement factor (TEF) at 5 wt.% h-BNNP loading was 78%, increasing to 468% at 25 wt.% h-BNNP loading. The maximum dielectric constant of approximately 36.37 (50Hz, 150 °C) was obtained at 25 wt.% h-BNNP loading, which was three times that of neat PVDF (11.94) at the same frequency and temperature. The aforementioned results suggest that these multifunctional and high-performance nanocomposites hold great promise for application in electronic encapsulation.

Solution-processed white graphene-reinforced ferroelectric polymer nanocomposites with improved thermal conductivity and dielectric properties for electronic encapsulation

Paper supported polystyrene membranes for thin film microextraction

In this study, novel three-phase polymer nanocomposites comprising of polyvinylidene fluoride (PVDF), titanium dioxide (TiO2) nanoparticles and graphene oxide (GO) were prepared using colloidal blending. The PVDF/TiO2/GO nanocomposites were characterized by FTIR, XRD, TGA, optical microscopy, SEM, AFM and contact angle analysis. The dielectric properties of these three-phase polymer nanocomposites were investigated using broadband dielectric spectroscopy in the frequency range 50 Hz–20 MHz and temperature in the range 40–150 °C. The FTIR and XRD results infer good interaction between the constituents of nanocomposites. The microscopic studies infer homogeneous dispersion and distribution of TiO2 nanoparticles and GO within the PVDF matrix. A notable improvement in the thermal stability of PVDF was observed by the addition of TiO2 and GO as hybrid fillers. The dielectric performance of PVDF/TiO2/GO nanocomposite films was significantly improved as compared to PVDF/TiO2 (90/10) nanocomposite film. The dielectric constant increases from 18.57 (50 Hz, 150 °C) for PVDF/TiO2 (90/10) nanocomposite film to 165.16 (50 Hz, 150 °C) for PVDF/TiO2/GO nanocomposite film containing 7 wt% TiO2 and 3 wt% GO loading. In addition, the dielectric loss also increases from 1.71 (50 Hz, 150 °C) for PVDF/TiO2 (90/10) nanocomposite film to 3.68 (50 Hz, 150 °C) for PVDF/TiO2/GO nanocomposite film containing 7 wt% TiO2 and 3 wt% GO loading. These intriguing properties of PVDF/TiO2/GO nanocomposites could shed some light on the incorporation of different types of hybrid fillers in a suitable polymer matrix for the development of novel three-phase nanocomposites as intelligent materials for embedded passive applications.

Striking multiple synergies in novel three-phase fluoropolymer nanocomposites by combining titanium dioxide and graphene oxide as hybrid fillers

Dielectric and electromagnetic interference shielding properties of zeolite 13X and carbon black nanoparticles based PVDF nanocomposites

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

A. R. Deshmukh Kalim

Papers

Studies on surface properties of polymeric coated paper material