Engineered Osmosis for Sustainable Water and Energy: Novel Nanofiber-supported Thin-film Composite Membrane Design & Updated Flux Model Proposal

Engineered osmosis (EO) is a state-of-the-art technology which harnesses the natural phenomenon of osmosis to address global issues related to water and energy. In this process, an osmotic pressure drives water across a semi-permeable membrane from a dilute feed solution to a concentrated draw solution. EO has the potential to sustainably produce fresh water at low energy cost, generate electricity and recover high-value dissolved solids. However, EO has not progressed beyond conceptualization and lab scale studies due to obstacles in membrane design, draw solution recovery, system integration, scale-up, and definitive process economics. This study focuses on addressing the primary obstacle to EO development: the lack of adequately designed membrane. Departing from traditional design of polyamide composite membrane, this dissertation presents one of the first known studies in which a novel thin-film composite/nanocomposite membrane supported on an effective nanofibrous structure was tailored for EO applications. With the integration of nanotechnology and membrane science, this membrane design shows immense promise as a next generation membrane platform for EO. Furthermore, this work shed insight on the critical structure � performance relationships with respect to mass transfer models for further advancing membrane design and EO development. It will eventually lead to widespread adoption of this emerging technology platform in sustainable water � energy production and life sciences.