NS-100 Membranes for Reverse Osmosis Applications

Abstract

The structure of the new NS-100 nonpolysaccharide reverse osmosis membranes and additional separation properties relating to removal of impurities from water has been investigated. Infrared spectrophotometric evidence has indicated that the urea linkages are formed before the heat cure step. The heat curing process was found to cross-link the polymer further by elimination of ammonia and formation of additional secondary and tertiary amine linkages. Long-term tests under seawater conditions have indicated water fluxes of 18 gfd at 99.5 percent salt rejection. The NS-100 membranes have exhibited high rejections toward organic compounds; for example, phenol is rejected up to 90 percent. All experimental data indicate that the NS-100 membranes are more resistant to varying environments with higher reverse osmosis performance than any current commercial membrane.