Highly selective cation exchange membranes were prepared by coating a thin 2-acrylamido-2-methylpropanesulfonic acid based hydrogel layer and super activated carbon nanoparticles-co-hydrogel layer on polyvinyl chloride based cation exchange membranes. FTIR analysis proved hydrogel formation on membrane surface successfully. Scanning electron microscopy images and swelling ratio measurement were used to study the effect of super activated carbon nanoparticles on properties of formed hydrogel. The surface morphology, surface hydrophilicity and roughness analysis were also used in membrane characterization. Membrane water content was increased by formation of modified layer on the membranes surface. Modified membranes showed a remarkable improvement in potential, permselectivity and transport number compared to pristine type. Membrane ionic flux and permeability were improved initially by using modifier layer on membrane surface, and then showed decreasing trend at high nanoparticles loading ratios in hydrogel layer. Modified membranes showed lower electrical resistance compared to unmodified membrane.