Ion Track Technology

PhysicsConsult

Reimar Spohr

PostHeaderIcon Abstract

Closure characteristics of a thermally responsive single ion track pore determined by size exclusion method. N. Reber, R. Spohr, A. Wolf, H. Omichi, M. Tamada, M. Yoshida. J. Membr. Sci. (1998), 140(2), 275-281.

Crosslinked poly(N-isopropylacrylamide) (NIPAAm) gel was grafted on the wall of a single ion-track pore in poly(ethylene terephthalate) (PET). The opening and closing of the pore is controlled by temp. and obsd. by elec. cond. In the shrunken state of the gel, ions and mols. can penetrate the membrane through the free vol. of the pore. In the swollen state, the gel clogs the pore. Using mixts. of polyethylene glycol (PEG) of various mol. wts. and 0.1 N potassium chloride, it was demonstrated that the responsive pore acts as a thermally controllable valve preventing the passage of PEG mol. larger than 2 nm. The mean value of the hydrogel mesh size is estimated. to be 1.3 (0.05) nm.