Pore formation by track etching of poly(vinylidene fluoride) films; Dependence on applied voltages during conductometric analysis

Yamaki, Tetsuya; Nuryanthi, N.*; Koshikawa, Hiroshi; Sawada, Shinichi; Asano, Masaharu; Maekawa, Yasunari; Katsumura, Yosuke*

A poly(vinylidene fluoride) film irradiated with 450 MeV Xe ions was etched in an aqueous potassium hydroxide solution at 80C in a conductometric cell. The etching characteristics were investigated in situ at different applied voltages. The conductometric curves reached a plateau when the etching time was sufficiently long (up to 48 h); this plateau indicates that etching was complete in the damaged track and that the bulk etch rate was negligibly low. The applied voltage produced larger pores than the etching with no voltage. Higher voltages shortened the etching time; the voltage accelerated the etching before the pore breakthrough and during the pore growth. The increase in the etch rate was probably caused by the dissolved etching products being pulled away from the pores more efficiently at higher applied voltages.