Modified poly(ethylene oxide) (PEO) networks have been studied as phase transfer catalysts, flocculates and solvent-free polymer electrolytes. The activity of the hydrogels has been investigated with respect to the structure and crosslinking density of the networks, their degree of quaternization and amphiphilic properties (hydrophilicity coefficients). It has been found that the microenvironment of the active sites (EO segments and ammonium ions) affects the catalytic activity and sorption ability of the modified networks. Hydrophobic organic compounds such as sodium picrate and bromophenolblue are bound predominantly to the lipophilic quaternary ammonium ions. A stable level of electrical conductivity of 5.0 X 10(-5) S cm(-1) was achieved without using of additives. A probable mechanism of ion transport within the networks has been proposed. Potential applications of PEO-based materials as solvent-free solid polymer electrolytes are also discussed. (C) 2002 Elsevier Science B.V. All rights reserved.