Effect of ion bombardment on the optical properties of LDPE/EPDM polymer blends

Ion bombardment is a suitable tool to improve the physical properties of polymers. In the present study, the effect of ion bombardment on the optical properties of low density polyethylene (LDPE)/Ethylene propylene diene monomer (EPDM) blend (LDPE/EPDM) was studied. Polymer samples was bombarded with 130 keV He and 320 keV Ar ions at fluencies levels ranging from 1 × 1013 to 2 × 1016 ions/cm2. The untreated and ion beam bombarded samples were investigated using ultraviolet-visible (UV-Vis) spectrophotometry. The optical band gap (Eg), was decreased from ∼2.9 eV for the pristine sample down to 1.7 eV for the samples bombarded with He and Ar ions at the highest fluences. Change in the optical gap indicates the presence of a gradual phase transition for the polymer blends. Activation energy has been investigated as a function of the ion fluences. With increasing ion fluence, a decrease in both the energy gap and the activation energy was observed. The number of carbon atoms (N) in a formed cluster is determined according to the modified Tauc's equation.