| 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. |