A cellulose acetate thin film composite (CA TFC) membrane was developed by direct casting of CA onto an ultrafiltration membrane support. The flux through the CA TFC membrane was, as expected, inversely proportional to the selective layer thickness. The membrane with the lowest thickness of the CA film (217 nm) initially had poor salt rejection (similar to 55%) but relatively high permeability (similar to 0.5 l m(-2) h(-1) bar(-1)). In contrast to asymmetric CA reverse osmosis membranes that are developed in 4 degrees C water baths, the CA TFC membranes were developed by subsequent swelling in room temperature water baths, thermal annealing at 81 degrees C, and with room temperature incorporation of silver nanoparLicles onto CA TFC surfaces by chemical reduction. The change in the physical properties as a result of the swelling process was examined with ellipsomerry, grazing incidence X-ray scattering and contact angle measurements. A combined swelling and annealing treatment was found to improve salt rejection to an acceptable reverse osmosis salt rejection level (similar to 94%) without significant deterioration of flux. The swelling time was found to generally improve the membrane performance in terms of flux and surface roughness whilst the silver nanoparLicle treatment reduced bacterial surface coverage by four orders of magnitude. (C) 2013 Elsevier B.V. All rights reserved