充电栅压对聚四氟乙烯多孔膜驻极体储电能力的影响

Influence of grid voltage on charge storage ability of porous PTFE film electrets

利用室温下栅控恒压电晕充电、热脉冲技术、开路热刺激放电电流谱以及对在充电过程中通过样品电流的监测等方法 ,系统地研究了充电栅压对具有开放性孔洞结构的聚四氟乙烯 (PTFE)多孔膜储电能力的影响 ,并讨论了导致这类影响的电荷动力学特性和材料的微结构根源 .结果显示 ,过高的充电栅压会导致沉积电荷密度下降和电荷衰减加剧 ,不利于这类新结构功能材料压电活性的提高及其热稳定性的改善 .合理的优化充电条件能使负极性充电PTFE多孔膜驻极体在有机聚合物材料中显示优异的储电能力及电荷稳定性 ,并改善其作为双极性空间电荷型压电传感膜的压电活性 .

The influence of grid voltage on charge storage ability of porous polytetrafluor oethylene (PTFE) film electrets has been systematically studied by means of c ons tant voltage corona charging with a grid, thermal pulse technique, open-circuit thermally stimulated discharge current spectra and monitoring the charging curr ent through samples during the charging. The origin of the influence has been d iscussed by using the charge dynamic characteristic and microcosmic structure an alysis of the materials. It was found that too high a grid voltage may lead to t he declination of charge density deposited in the porous sample and enhance the charge decay, and thus, to the decrease of piezoelectricity and thermal stabilit y of the porous film. For negatively corona charged porous PTFE, excellent charg e storage ability can be performed at an optimal grid voltage, which will improv e its piezoelectric activity in the application to the electret piezoelectric se nsor film with dipolar space charges.