“…These studies have all indicated major physical and chemical property changes in the surface regions of the polymers, which may or may not be permanent, depending on the fluence. In most cases, there are significant changes in the mechanical (Lee et al, , 1997Nishimiya et al, 1991;Lee, Lee, & Mansur, 1992;Ochsner et al, 1993;Rao, Wang, & Lee, 1993;Rao et al, 1995;Tretinnikov & Ikada, 1998), chemical (Puglisi et al, 1986;Nishimiya et al, 1991;Lee et al, 1993Lee et al, , 1997Š vorčík et al, 1998;Tretinnikov & Ikada, 1998), electronic (Forrest et al, 1982;Venkatesan et al, 1983;Liu, Liu, & Zhai, 1989;Lee et al, 1993;Š vorčík et al, 1997), diffusion (Calcagno et al, 1993), optical (Calcagno, Compagnini, & Foti, 1992;Rück, Schulz, & Beusch, 1997), and rheological properties (Calcagno, Compagnini, & Foti, 1992) of ion-bombarded polymeric samples. These changes are obviously a result of the increased crosslinking and unsaturation occurring in these polymers.…”