Nanopores with controlled profiles in track-etched membranes

Track-etched membranes are porous systems consisting of a polymer foil with thin channels-pores from surface to surface. The increasing interest in this kind of material is connected with the development of nanoporous materials with unique properties such as diode-like effects in membranes with highly asymmetrical nanopores. The materials can be used for molecular sensors and atom beam optics, development of nanocapillary bodies for modelling the transport of molecules and ions in constrained volumes. Control over pore geometry opens the way to a number of new applications of track-etch membranes (TMs). The nanopores were obtained by the ion-track etching method using surfactant-doped alkaline solutions. Control over the pore profile and dimensions was achieved by varying the alkali concentration in the etchant and the etching time. The pore geometry was characterized in detail using field-emission scanning electron microscopy (SEM). SEM images of the surfaces and cleavages of TMs with different pore morphology are shown.