Smart grafted polymer networks comprising random copolymer of poly(acrylic acid-co-acrylamide) and polyvinyl alcohol and exhibiting extraordinary water imbibtion property were prepared by free radical polymerization method and characterized by Fourier Transform infrared spectroscopy, Ultra Violet spectroscopy, Environmental Scanning Electron Microscopy, Thermogravimetric Analysis, Differential Scanning Calorimetry, and X-ray Diffraction. The mesh size (xi) and chain flexibility factor (alpha) of interpenetrating polymer networks were calculated for various grafted polymer network compositions and correlated with their water sorption capacity. (c) 2006 Wiley Periodicals, Inc.