Preparation of fluoropolymer-based ion-track membranes; control of pore size and shape by track structures

Yamaki, Tetsuya; Nuryanthi, N.*; Koshikawa, Hiroshi; Sawada, Shinichi; Asano, Masaharu; Maekawa, Yasunari; Voss, K.-O.*; Christina, T.*

Our focus has been placed on ion-track membranes of poly(vinylidene fluoride) (PVDF), a type of fluoropolymer. Here we investigated the track-structure-dependent pore formation by scanning electron microscopy and conductometry to control the pore size and shape by direct use of the irradiation effect. According to the study of the films irradiated with different ions, the diameter of the etched pores actually depended on the deposited energy within each track represented by the linear energy transfer (LET). The depth distribution of the LET was then applied to control the pore shape, in other words, to prepare nanopores with a conical as well as cylindrical shape.