Abstract: | The permeabilities and selectivities of O3, O2, and N2 through silicone capillary membranes employed to degrade organic pollutants in water or air have been experimentally determined. These characteristics have been studied for silicone membranes used in membrane reactors having the following conditions: O3 in O2 on one side of the membrane, and either water containing pollutants or a perfluorocarbon (FC) phase containing pollutants on the other side. The permeability of O3 (8.8 e-13 kgmol · m/m2 · s · kPa) is four times that of O2 through virgin silicone rubber. Exposure to O3 modifies the polymer and alters the permeabilities of O3 and O2. The presence of water with O3 leads to an increase in O3 and O2 permeability (∼ 30%) and an increase in the selectivity, (∼ 10%). The increased permeabilities are likely to be due to the formation of peroxides on the surface and possibly in the polymer. When the silicone capillary membranes were exposed to a perfluorocarbon (FC), the permeabilities of O3 and O2 decreased (∼ 9%) due to an increase in crosslinking in the polymer matrix; there was also a slight increase in (∼ 2%), which can be ascribed to the smaller molecular sieving radius of O2 compared to N2. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 1263–1273, 1998 |