Expanded Glassy Polymers and Polyelectrolyte Complexes as Reverse Osmosis and Ion-Selective Membranes

摘要

The results of the investigation showed that by varying the membrane preparation conditions it is possible to control the permeability of the film to dissolved salts. For a given material, however, reduction of the salt permeability usually coincides with reduction of the water flux through the membrane. Many of the materials studied in this investigation show very high salt rejection. For example, cellulose nitrate and hydroxycthyl metacrylate (HEMA) both show salt rejections in excess of 90% at low flow rates, while polyurethanes are just below that value for salt rejection. For each of these three materials new techniques were developed to control the water flux and salt rejections, and the technology is now available to control the properties of a variety of hydrophilic polymers. The most promising materials for use in reverse osmosis developed on this program appear to be polyurethanes and HEMA. Both of these, however, still must be prepared as ultrathin films. Other significant resluts of this investigation have been the development of new characterization techniques to more fully describe polymer properties and to predict performance. (Author)