Polymer nanocomposite

About: Polymer nanocomposite is a research topic. Over the lifetime, 8977 publications have been published within this topic receiving 297599 citations.

A Hybrid Material Approach Toward Solution‐Processable Dielectrics Exhibiting Enhanced Breakdown Strength and High Energy Density

Abstract: The ever-increasing demand for compact electronics and electrical power systems cannot be met with conventional dielectric materials with limited energy densities. Numerous efforts have been made to improve the energy densities of dielectrics by incorporating ceramic additives into polymer matrix. In spite of increased permittivities, thus-fabricated polymer nanocomposites typically suffer from significantly decreased breakdown strengths, which preclude a substantial gain in energy density. Herein, organic–inorganic hybrids as a new class of dielectric materials are described, which are prepared from the covalent incorporation of tantalum species into ferroelectric polymers via in situ sol-gel condensation. The solution-processed hybrid with the optimal composition exhibits a Weibull breakdown strength of 505 MV m−1 and a discharged energy density of 18 J cm−3, which are more than 40% and 180%, respectively, greater than the pristine ferroelectric polymer. The superior performance is mainly ascribed to the deep traps created in the hybrids at the molecular level, which results in reduced electric conduction and lower remnant polarization. Simultaneously, the formation of the cross-linked networks enhances the mechanical strengths of the hybrid films and thus hinders the occurrence of the electromechanical breakdown. This work opens up new opportunities to solution-processed organic materials with high energy densities for capacitive electrical energy storage.

Synergistic effect of multi walled carbon nanotubes and reduced graphene oxides in natural rubber for sensing application

Abstract: Utilizing the electrical properties of polymer nanocomposites is an important strategy to develop high performance solvent sensors. Here we report the synergistic effect of multi walled carbon nanotubes (MWCNTs) and reduced graphene oxide (RGO) in regulating the sensitivity of the naturally occurring elastomer, natural rubber (NR). Composites were fabricated by dispersing CNTs alone and together with exfoliated RGO sheets (thermally reduced at temperatures of 200 and 600 °C ) in NR by a solution blending method. RGO exfoliation and the uniform distribution of fillers in the composites were studied by atomic force microscopy, Fourier transformation infrared spectroscopy, X-ray diffraction, transmission electron microscopy and Raman spectroscopy. The solvent sensitivity of the composite samples was noted from the sudden variation in electrical conductivity which was due to the breakdown of the filler networks during swelling in different solvents. It was found that the synergy between CNTs and RGO exfoliated at 200 °C imparts maximum sensitivity to NR in recognizing the usually used aromatic laboratory solvents. Mechanical and dynamic mechanical studies reveal efficient filler reinforcement, depending strongly on the nature of filler–elastomer interactions and supports the sensing mechanism. Such interactions were quantitatively determined using the Maier and Goritz model from Payne effect experiments. It is concluded that the polarity induced by RGO addition reduces the interactions between CNTs and ultimately results in the solvent sensitivity.

Development of Fabrication Methods of Filler/Polymer Nanocomposites: With Focus on Simple Melt-Compounding- Based Approach without Surface Modification of Nanofillers

Abstract: Many attempts have been made to fabricate various types of inorganic nanoparticle-filled polymers (filler/polymer nanocomposites) by a mechanical or chemical approach. However, these approaches require modification of the nanofiller surfaces and/or complicated polymerization reactions, making them unsuitable for industrial-scale production of the nanocomposites. The author and coworkers have proposed a simple melt-compounding method for the fabrication of silica/polymer nanocomposites, wherein silica nanoparticles without surface modification were dispersed through the breakdown of loose agglomerates of colloidal nano-silica spheres in a kneaded polymer melt. This review aims to discuss experimental techniques of the proposed method and its advantages over other developed methods.