Effect of temperature and α-irradiation on gas permeability for polymeric membrane

In the present study the polyethersulphone (PES) membranes of thickness (35 ± 2) µm were pre- pared by solution cast method. The permeability of these membranes was calculated by varying the temper a- ture and by irradiation of α ions. For the variation of tem perature, the gas permeation cell was dipped in a constant temperature water bath in the temperature range from 303-373 K, which is well below the glass transition temperature (498 K). The permeability of H 2 and CO2 increased with increasing temperature. The PES membrane was exposed by α-source (95Am 241 ) of strength (1 µ Ci) in vacuum of the order of 10 -6 torr, with fluence 2· ·7 × 10 7 ions/cm 2 . The permeability of H 2 and CO2 has been observed for irradiated membrane with increasing etching time. The permeability increases with increasing etching time for both gases. There was a sudden change in permeability for both the gases when observed at 18 min etching. At this stage the tracks are visible with optical instrument, which confirms that the pores are genera ted. Most of pores seen in the micrograph are circular cross-section ones.