Abstract: In this paper, PTFE/YSZ composite microporous membrane was prepared by mechanical tension of a PTFE emulsion containing YSZ micro/nanoparticles. The structure and performance of PTFE/YSZ composite microporous membrane were characterized uisng scanning electron microscope (SEM). The effects of the dispersant PVA, draw ratio, YSZ content, and calcination temperature on the porosity of composite microporous membrane were systematically investigated. It was found that the porosity increased significantly with increasing PVA and YSZ contents. The porosity reached 73.09 % when the draw ratio was 3.5 times, YSZ contents 8 %, and the calcinations temperature 320 ℃.

Key words: polytetroflunoroethylene, yttria stabilized zirconia, microporous membrane, porosity