Grafting by gamma irradiation has a significant influence on the dispersion properties of polymeric materials. Accordingly, we study the effect of grafting on the material electronic structure parameters such as the fundamental absorption edge and bandgap structure. The optical absorption of grafted polymeric films of poly(tetrafluoroethylene-co-perfluorovinyl ether) (PFA-g-PAAc) is determined in a very wide spectral range of 0.2-3 mu m. The nonlinear two-photon absorption coefficient is determined that showed an increase as a result to the grafting process. Moreover, a significant increase in the optical conductivity for the polymeric films is acquired after grafting. Positron annihilation spectroscopy is used to study polymer structure and volume size of nanoholes of Ps. The data revealed an increase of crosslinking with a smaller average volume size with grafting. (C) 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 2045-2051, 2010