Laboratory-made polydimethylsiloxane (PDMS) membranes were subjected to plasma treatments with three different plasmas: an Ar, Ar-H-2 and Ar-O-2 plasma. Two parameters of the Ar-O-2 treatment, the applied power and the treatment time, were evaluated. The effects of these treatments on the PDMS-membranes were studied through the use of XPS-analysis, contact angle measurements and surface energy calculations. The plasmatreated membranes were tested in the filtration of three selected dyes: methylene blue, methyl orange and disperse red 1. From these experiments insight in the transport mechanism for solvent resistant nanofiltration (SRNF) through the plasma-treated membranes was gained. (c) 2005 Elsevier B.V. All rights reserved.