Investigation of nanopore evolution in track-etched poly(vinylidene fluoride) membranes

ポリフッ化ビニリデンイオン穿孔膜におけるナノ孔成長の検討

八巻 徹也; Nuryanthi, N.*; 越川 博; 浅野 雅春; 澤田 真一; 長谷川 伸; 前川 康成; Voss, K.-O.*; Trautmann, C.*; Neumann, R.*

Yamaki, Tetsuya; Nuryanthi, N.*; Koshikawa, Hiroshi; Asano, Masaharu; Sawada, Shinichi; Hasegawa, Shin; Maekawa, Yasunari; Voss, K.-O.*; Trautmann, C.*; Neumann, R.*

化学的,熱的に安定なフッ素系高分子、特にポリフッ化ビニリデンからなるイオン穿孔膜に着目し、そのエッチング挙動や応用性に関する研究を進めている。今回は、コンダクトメトリーによって穿孔形成過程を解析し、照射イオン種や測定セルへの印加電圧が及ぼす影響を調べたので報告する。孔貫通に至るまでの化学エッチングは、高いLETを有する重イオンビームを照射するとともに、セル電圧を高く維持することによって大きく加速されるという興味深い現象を見いだした。

The aim of this study is to investigate the formation of the poly(vinylidene fluoride) (PVDF) track membranes in detail by electrolytic conductometry. A PVDF film was irradiated with a 450 MeV Xe or 2.2 GeV Au ion beam, and then the latent tracks were etched in a 9 mol dm aqueous KOH solution at 80C that had been poured into a conductometric cell. At the same time, the evolution of cylindrical nanopores was monitored by measuring the conductance through the membrane. The etching kinetics significantly depended on the deposited energy within each track, which is represented by the LET. Interestingly, applying a higher voltage to the cell promoted track etching up to the breakthrough probably because the electrophoretic migration of dissolved products occurred out of each pore.