Track etching technique in membrane technology

Track membrane (TM) technology is an example of industrial application of track etching technique. Track-etch membranes offer distinct advantages over conventional membranes due to their precisely determined structure. Their pore size, shape and density can be varied in a controllable manner so that a membrane with the required transport and retention characteristics can be produced. The use of heavy ion accelerators made it possible to vary LET of track-forming particles, angle distribution of pore channels and pore lengths. So far the track formation and etching process has been studied in much detail for several polymeric materials. Today we understand determining factors and have numerous empirical data enabling us to manufacture any particular product based on polyethylene terephthalate (PET) or polycarbonate (PC) films. Pore shape can be made cylindrical, conical, funnel-like, or cigar-like at will. A number of modification methods has been developed for creating TMs with special properties and functions. Applications of "conventional" track membranes can be categorized into three groups: process filtration, cell culture, and laboratory filtration. The use in biology stands out among other areas. Nuclear track pores find diverse applications as model systems and as templates for the synthesis of micro- and nanostructures. (C) 2001 Elsevier Science Ltd. All rights reserved.