Nano-fabrication of novel ion track membranes for separation filters

Polyethylene terephthalate (PET) ion track membranes with different pore diameters are applied to size-exclusion membranes. By changing the pore diameter from 45 to 140 nm, the polyethylene glycols are clearly separated to each other. Blood proteins, albumin and γ-globulin, are also completely separated by passing through the PET membranes with the pore diameters ranging from 180 to 270 nm. Thermally stable polymer membranes for ion and electron beam radiation are developed by means of the precursor polymer films of thermally stable polymers. When the partially imidized polyamic acid films, which are the precursor of the thermally stable polyimides, are irradiated with Xe ion beams followed by alkaline etching, both negative (projection) and positive (hole) images of polyimide films are obtained due to the slight different polymer structures. (author)