Influence of charging conditions of porous polytetrafluoroethylene (PTFE) film electrets on the permeability of membranes

Author

Xia, Z. ; Buchtemann, A. ; Danz, R. ; Wedel, A. ; Jian, J.

Author_Institution

Pohl Inst. of Solid State Phys., Tongji Univ., Shanghai, China

fYear

2002

fDate

2002

Firstpage

203

Lastpage

206

Abstract

In this paper, the influence of charging conditions on the permeability of porous PTFE membranes is studied by constant voltage corona charging at room and elevated temperatures and by measuring the relative flow rate in water when porous PTFE electret films are used as filter membranes. We found that charging field and charging temperature strongly affect the relative flow rate of water. The structure of porous PTFE, investigated by a scanning electron microscope, is important for understanding the influence of charging conditions on material permeability. The increase of the ratio of bulk charge density to surface charge density of the porous films was performed by thermal treatment during charging. Such porous films may be employed as electret filter membranes for purification of dielectric liquids.

Keywords

dielectric liquids; dielectric thin films; electrets; electric charge; filtration; heat treatment; membranes; permeability; polymer films; porous materials; scanning electron microscopy; surface charging; SEM; bulk charge density; charging conditions; charging field; charging temperature; constant voltage corona charging; dielectric liquid purification; electret filter membranes; elevated temperatures; permeability; polytetrafluoroethylene film; porous PTFE film electrets; porous PTFE membranes; relative flow rate; room temperature; scanning electron microscopy; surface charge density; thermal treatment; Biomembranes; Corona; Dielectric materials; Electrets; Filters; Fluid flow measurement; Permeability measurement; Scanning electron microscopy; Temperature measurement; Voltage;

fLanguage

English

Publisher

ieee

Conference_Titel

Electrets, 2002. ISE 11. Proceedings. 11th International Symposium on

Print_ISBN

0-7803-7560-2

Type

conf

DOI

10.1109/ISE.2002.1042979

Filename

1042979