Polymer nanocomposite

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

Many body effects on the phase separation and structure of dense polymer-particle melts

Abstract: Liquid state theory is employed to study phase transitions and structure of dense mixtures of hard nanoparticles and flexible chains (polymer nanocomposites). Calculations are performed for the first time over the entire compositional range from the polymer melt to the hard sphere fluid. The focus is on polymers that adsorb on nanoparticles. Many body correlation effects are fully accounted for in the determination of the spinodal phase separation instabilities. The nanoparticle volume fraction at demixing is determined as a function of interfacial cohesion strength (or inverse temperature) for several interaction ranges and nanoparticle sizes. Both upper and lower critical temperature demixing transitions are predicted, separated by a miscibility window. The phase diagrams are highly asymmetric, with the entropic depletion-like lower critical temperature occurring at a nanoparticle volume fraction of ∼10%, and a bridging-induced upper critical temperature at ∼95% filler loading. The phase boundaries are ...

High Dielectric and Mechanical Properties Achieved in Cross-Linked PVDF/α-SiC Nanocomposites with Elevated Compatibility and Induced Polarization at the Interface

Abstract: Remarkably improved dielectric properties including high-k, low loss, and high breakdown strength combined with promising mechanical performance such as high flexibility, good heat, and chemical resistivity are hard to be achieved in high-k dielectric composites based on the current composite fabrication strategy. In this work, a family of high-k polymer nanocomposites has been fabricated from a facile suspension cast process followed by chemical cross-linking at elevated temperature. Internal double bonds bearing poly(vinylidene fluoride-chlorotrifluoroethylene) (P(VDF-CTFE-DB)) in total amorphous phase are employed as cross-linkable polymer matrix. α-SiC particles with a diameter of 500 nm are surface modified with 3-aminpropyltriethoxysilane (KH-550) as fillers for their comparable dielectric performance with PVDF polymer matrix, low conductivity, and high breakdown strength. The interface between SiC particles and PVDF matrix has been finely tailored, which leads to the significantly elevated dielectr...

Performance of dielectric nanocomposites: matrix-free, hairy nanoparticle assemblies and amorphous polymer-nanoparticle blends.

Abstract: Demands to increase the stored energy density of electrostatic capacitors have spurred the development of materials with enhanced dielectric breakdown, improved permittivity, and reduced dielectric loss. Polymer nanocomposites (PNCs), consisting of a blend of amorphous polymer and dielectric nanofillers, have been studied intensely to satisfy these goals; however, nanoparticle aggregates, field localization due to dielectric mismatch between particle and matrix, and the poorly understood role of interface compatibilization have challenged progress. To expand the understanding of the inter-relation between these factors and, thus, enable rational optimization of low and high contrast PNC dielectrics, we compare the dielectric performance of matrix-free hairy nanoparticle assemblies (aHNPs) to blended PNCs in the regime of low dielectric contrast to establish how morphology and interface impact energy storage and breakdown across different polymer matrices (polystyrene, PS, and poly(methyl methacrylate), PM...

Design and Synthesis of Polymer Nanocomposites

Abstract: Polymer nanocomposites are probably the most versatile materials today. They do not only possess excellent properties but can also be made to exhibit combination of properties for multifunctional applications. They are useful in almost every area of life including sports, automotive, aerospace, electronics, electrical, marine, energy, etc. Development of these high-performance nanocomposites requires thorough design, material selection, and synthesis. It involves the selection of polymers and fillers out of the vast number of polymers and fillers available today in search for the required property. It also involves determination of the best production process, considering the end use requirements, and finally fabrication of the material. This underscores the importance of the design and synthesis phases of polymer nanocomposite production. In this chapter we have outlined in detail the design process and synthesis techniques for polymer nanocomposite production. In-depth analysis of design strategies, principles, and mechanisms that guide appropriate design are presented. The most commonly used synthesis techniques, including ultrasonication-assisted solution mixing, shear mixing, three roll milling, ball milling, double-screw extrusion, as well as other ex situ and in situ processing methods, are discussed in the context of their applicability to different nanofillers and matrices, the controlling parameters, and the scalability for industrial applications.