Electret composite with deep trapping centers on the interphase boundary

Abstract

An electret composite comprising a polymer matrix material that contains particles of a piezoelectric material with deep trapping centers on the interphase boundaries between the matrix and particles of a piezoelectric material. The piezoelectric material may have a tetragonal or a rhombohedral structure, and the polymer matrix material may be selected from high-density polyethylene, polyvinylidene fluoride, and a copolymer of vinylidenechloride and tetrafluoroethylene. The composite has a potential difference> 500V, lifespan> 10 years, dielectric permeability≧ 20, specific electric resistance≧ 10 14 Ohm· m; provision of deep trapping centers on the interphase boundaries with activation energy in the range of 1 to 1.25 eV, and stable electret charge.