Hydrophilic-Hydrophobic Nanostructured Polymeric Materials for Desalination

Abstract

This paper deals with results from a systematic study of the desalination properties of a new family of hydrophilic-hydrophobic copolymers (e.g., sulfonated poly(arylene ether sulfone)s). These polymers prepared via a novel synthesis involving direct copolymerization of non-sulfonated monomers with a disulfonated monomer. By tailoring morphologies consisting of hydrophilic and hydrophobic domains in such copolymers, desalination properties, such as water permeability and salt rejection, can be varied over a wide range. A family of materials, based on random copolymers, microphase-separated block copolymers, blends, and crosslinked materials may be prepared from these starting monomers to provide a new platform for desalination membranes. We also find that there is a general tradeoff, similar to that observed in gas separations, between water/salt permeability selectivity and water permeability. The fundamental basis for this tradeoff relation will be discussed and its implications for membrane materials design will be addressed.