Molecular Dynamics Studies on the Dispersion of Silica Nanoparticles in Polyethylene Melt Using a Coarse-Grained Model

摘要

Particles are important additives for altering and enhancing the properties of polymers. When the particle size approaching the fundamental length scale of the material, new mechanical, optical, and electrical properties arise, which are not present in the conventional macroscopic counterpart. For example, the dielectric constant of a polymer fluid can be increased by addition of ceramic nanoparticles with high permittivity. Some new polymeric and ceramic materials have been identified as promising candidates for the fabrication of high dielectric strength capacitors. Systems, such as titania, strontium titanate, and barium titanate dispersed in perfluoropoly(ether), poly(dimethyl siloxane), and poly(butadiene), have been investigated in several experimental works. In addition, silica (SiO2) nanoparticles embedded in a polyethylene (PE) melt has been identified to offer desired dielectric constants. For this system, experimental study by Riman et al. [1] indicates that at nanoparticle filling fractions of 1 vol%, a 50% increase in the electroluminiscence and dielectric constant is observed.