Preparation and Properties of Graphene Oxidepolymer Desalination Membranes

Demand for desalination capabilities comes from industries as varied as energy, agriculture, and public utilities. The vast array of water sources and differing requirements for purified water indicate that a variety of technologies will probably be needed to meet the demands. One such technology is based on the use of layered graphene oxide (GO) membranes to remove dissolved salts and other contaminants by a size exclusion mechanism. Relative to state-of-the-art polyamide-based thin film composite reverse osmosis membranes, graphene oxide\polymer membranes are chemically and thermally stable. These inherent advantages allow for membrane exposure to chlorine at levels commonly used to prevent biofouling as well as the immediate desalination of heated water from sources such as cooling towers, power plants, and oil and natural gas extraction processes.

Sandia has developed a method for preparing robust, functional GO membranes that have specific ion rejections as high as 98% while tolerating continuous 1-3 mg/L chlorine exposure. Assembling robust, functional membranes that are large enough for crossflow testing presents several challenges. This presentation will focus on the selection and surface treatment of the porous substrate, optimization of graphene oxide adhesion to the substrate, and the process for assembling even layers of graphene oxide. Membrane performance testing in cross flow systems demonstrating both chlorine tolerance and biofouling resistance will also be included.

Sandia National Laboratories is a multimission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC., a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA-0003525.