Freestanding and Permselective Graphene Oxide Membranes Assembled at Liquid/Liquid Interface through Novel "Stitch Chemistry"

University Of Akron, Akron OH

Investigators

Abstract

Proposal Number: 1603264, PI: Zhu, Jiahua Title: Chemically Stitching Graphene Oxide Nanosheets into Separation Membranes Purifying water from processing streams with low energy consumption is urgently needed in the chemical, petrochemical and bioengineering industries. In addition, conventional polymer- and ceramic-based membrane technologies have significant challenges in biofuel separations. Graphene oxide (GO, a sheet material with a thickness less than 1.0 nm) has been explored as a membrane material with great potential in water separations. The membrane would consist of layers of this sheet material. The proposed research will use novel "stitch" molecules as a tool to assemble GO sheets into a membrane with desired microstructure pattern and layer spacing. These membranes are designed to achieve permselective separation of water in a broad range of separation practices. The outcome of this research is to offer a transferrable freestanding membrane processing technology that is capable to revolutionize biofuel separation efficiency, and greatly improve water purification capability. The educational broader impacts are addressed through professional training of graduate students, development of graduate curriculum and promoted STEM education and engagement in focused outreach activities to pre-college students. This research focuses on the fundamental understanding of interfacial transport, reaction kinetics, and self-assembly phenomena of graphene oxide sheets into freestanding membranes at using polymerization chemistry facilitated by a liquid/liquid interface. The self assembly at the liquid/liquid interface will be enabled with the use of novel stitching molecules to impact the layer to layer spacing of the GO membrane, the formation of the membrane surface, and the surface chemistry of the pore channels. The research will use examples of biofuel separation and water purification applications to test the selectivity and permeability of the resultant membranes. The specific research goals are to: 1) understand the transport behavior and assembly phenomena of GO sheets into membranes at the liquid/liquid interface; 2) tune GO membrane pore microstructure and surface chemistry properties using reactive groups in the GO basal planes to impact the membrane's structure and chemical function; and 3) reveal the process-structure-property relationships of GO membranes targeting permselective biofuel separation and water purification applications. The transferability of this technology will enable its immediate dissemination to a wide range of separation applications.