Formation of nano tracks in PES films characterized by hydrogen transport and mechanical properties

The modifications in poly (ethersulfone) PES membranes induced by swift heavy ion irradiation are analyzed. PES membrane of 25 μm was irradiated by Cl9+ ions of 120 MeV at IUAC New Delhi, India with ion fluence of 106–108 ion/cm2. The changes due to exposure to high-energy ions were investigated by Dynamic mechanical analysis and gas permeation. The strength of the polymer membranes increases with increasing ion fluence. Gas permeation through these membranes before and after irradiation using hydrogen and carbon dioxide gases shows that permeability for both gases increased after irradiation but permeability for hydrogen is higher than carbon dioxide due to its small molecular size. This is due to the larger electronic energy loss by Cl+9 ions creating large damage area, which is etched rapidly and large permeability is observed in the less etching time. The gas permeability of both the gases are almost found same from both the side of the membrane consequently, the shape of the tracks is almost cylindrical.