(PEO)(8)ZnCl2 polyelectrolytes and nanocomposites were prepared using PEO gamma-irradiated to selected doses and TiO2 nanograins and were studied by impedance spectroscopy, DSC, optical microscopy and FTIR. Room-temperature conductivity increase up to two orders of magnitude was achieved. The crystallinity significantly decreased with radiation dose increase due to crosslinking of PEO. Addition of nanograins caused an increase in conductivity to a significantly larger extent than can be ascribed to crystallinity, possibly because of interactions of anion with nanograins. (c) 2005 Elsevier B.V. All rights reserved.