Radiation Measurements 34 (2001) 593–595 www.elsevier.com/locate/radmeas The track membrane porous structure and selective properties investigation V.V. Beriozkin a ; ∗ , D.L. Zagorsky a , A.N. Nechaev a , T.V. Tsiganova a , N.V. Mitrofanova a , P.Yu. Apel b , B.V. Mchedlishvili a a Shubnikov Institute of Crystallography of Russian Academy of Science, Leninsky pr., 59, 117333, Moscow, Russia b G.N. Flerov Laboratory of Nuclear Reactions, Joint Institute of Nuclear Research, Dubna, Russia Received 28 August 2000; received in revised form 25 January 2001; accepted 23 March 2001 Abstract The dierence between track membrane pore diameter values, obtained with methods of “bubble point” (DBP), hydrody- namics (DHD) and scanning electron microscopy (DSEM), was investigated. It was found that DSEM ¿DHD ¿DBP and this relation is signicant for small pore. This phenomenon is explained on the basis of “double-cone” pore shape. The equation was derived, which presented a relation between these values. The results of calculation were compared with experimental results. The dependence of track membranes tested selectivity on particle size-to-pore size relation was obtained in experiment on latex particles ltration. It was shown, that this dependence is eected by the pore diameter calculation method. c 2001 Elsevier Science Ltd. All rights reserved. Keywords: Track membrane; Pore diameter; Selectivity 1. Introduction The track membrane (TM) is one of the most important practical application of accelerators techniques. Two-step process—irradiation by accelerated high-energy ions and chemical etching of latent tracks—is usually used for TM production. The selectivity or rejection ability, ’ is the main mem- brane characteristic. It is dened with ’ =(1 - Cp=C0)100%; (1) where ’ is the selectivity, Cp is the permeate concentration and C0 is the initial solution concentration. The parameter , the ratio of particle size (d) to pore size (D), is one of the basic parameters, operating on the mem- brane selectivity, out of dependence of the particle—pore surface interaction nature. The relationship ’() allows to * Corresponding author. Tel.: +7-95-1357349; fax: +7-95-1351011. E-mail address: track@imb.ac.ru (V.V. Beriozkin). choose optimal membrane structure that results in maximum eciency at given selectivity. In ultra and microltration, the ow-through membrane is pressure-driven (it is oper- ated with dierence of pressure, applied across membrane). The peculiarities of physico-chemical particle–pore surface interaction do not aect the selectivity signicantly in this case. As a result, the relationship ’() must be identical for membranes of various types (Mchedlishvili et al., 1993). The standard system must be chosen to obtain the univer- sal ’() relationship. It is impossible to use the membranes of traditional “reticulate” structure as standard porous sys- tem because of their pore structure and pore diameter uncer- tainty. So, TM characterised with regular porous structure and narrow pore size distribution, must be used. The aque- ous solution of hard spherical latex particles may be used as a model suspension. The system “TM-aqueous latex suspen- sion” was used in (Cherkasov et al., 1978) to obtain ’() relationship for TM. The principal result of this work was the critical value of 0.32, when selectivity became 100%. We think that this value is too small. Probably, it was con- sequence of pore diameter evaluation error. As was reported 1350-4487/01/$-see front matter c 2001 Elsevier Science Ltd. All rights reserved. PII:S1350-4487(01)00235-9