The comparative studies of charge storage stabilities among three PP/porous PTFE/PP electret

In this paper, PP/porous PTFE/PP electret, pressure sensitive adhesive PP/porous PTFE/PP electret and PP/porous PTFE/PP electret drug transdermal patch were prepared. By means of the surface potential decaying measurement and thermal discharge method, the charged storage stability was compared among them. The results indicated that (1) negative PP/porous PTFE/PP electret could still hold 93.4% of its initial surface potential when it was kept at RT for 16 days and exhibited better charge storage stability than positive electret. (2) The humidity almost had no influence in the charge storage stability of the electret. (3) The positive and negative PP/porous PTFE/PP adhesive electret could respectively hold 87.5% and 75.6% of their initial surface potential when being kept at room temperature for 13 days. The adhesive had a little influence in the charge storage stability of the electret. (4) Both the negative and positive PP/porous PTFE/PP electret drug transdermal patch had excellent charge storage stability. (C) 2009 Elsevier B.V. All rights reserved.