| Biography | |
|---|---|
 Prof. Gongping Liu Chemical Engineering at Nanjing Tech University, China |
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| Title: Graphene Oxide Membranes for Molecular Separation | |
| Abstract: Molecular separations are widely used in the oil and gas, energy and chemical industries, but are energy intensive. Compared with conventional separation processes such as evaporation and distillation, membrane technology used for molecular separation can reduce energy consumption by an order of magnitude. However, the conventional polymeric membranes suffer a trade-off between permeability and selectivity. Alternatively, inorganic membranes, with well-defined nanostructures, could achieve both high permeance and selectivity for molecular separation. Among them, two-dimensional materials with atomic thinness can serve as new building blocks for fabricating ultrathin membranes possessing the ultimate permeation rate. The apertures of two-dimensional-material membranes, including the in-plane nanopores and interlayer channels, can contribute to the fast and selective transport of small molecules/ions related to molecular separation. This presentation will give an overview of our recent progresses on GO membranes for molecule and ion transport, with a focus on our attempts on tuning the fast and selective channels within the membrane. We demonstrate a scalable fabrication of GO membranes on ceramic hollow fiber substrate and propose a novel bio-inspired strategy is proposed to utilize the synergistic effect of a hydrophilic polymer and GO laminates to realize fast water-transport channels for constructing high-efficiency membrane for pervaporation dehydration of aqueous organic solution. For gas separation, we design a novel type of membrane with fast and selective gas-transport channels of GO laminates enabled by polymer-GO hydrogen bonding, showing excellent CO2 permeation performance. A facile methodology of external forces driven assembly is proposed to precisely manipulate the GO membranes with highly ordered 2D microstructure for precise molecular gas separation. Such well-defined nanochannels are also achieved in ultrathin MXene membrane and show a transformation from “diffusion-control” to “solution-control” after chemical tuning. For water purification, we demonstrate nanoparticles (NPs)@GO membranes with significantly expanded inter-layer channels meanwhile ordered laminar structures, exhibiting ultrahigh water permeance. To further realize ion separation, we achieved facile and precise control of the interlayer spacing in GO membranes, with a precision of down to 1 Å, and corresponding ion rejection, through the addition of one kind of cation. The study on surface-charged GO membrane provides another approach to realize controllable ion transport without impeding water filtration though GO membrane. In our very recent study, we proposed molecular bridges to stabilize GO membranes in water. | |
| Biography: Dr. Gongping Liu is a professor in Chemical Engineering at Nanjing Tech University, China. He received his BS degree and PhD degree in chemical engineering in 2008 and 2013 at Nanjing Tech University under the supervision of Prof. Wanqin Jin and Prof. Nanpin Xu. Following completion of his PhD, Dr. Liu joined Nanjing Tech University as a lecturer, and undertook a post-doctoral position in Bill Koros Group at Georgia Tech during 2015-2017. His research area is membrane science and technology, with focusing on design and fabrication of novel membranes with subnano-sized pores for molecular separation. He is the principal investigator of various projects such as the National Natural Science Foundation of China. His work has led to 110 journal papers in Nature, Nature Materials, Nature Energy, Nature Communications, Angewandte Chemie, Chemical Society Reviews, AIChE Journal, Journal of Membrane Science et al., with over 5900 citations and H-index 40; 1 monograph and 5 book chapters; He is the section editor of BMC Chemical Engineering, recipient of the North American Membrane Society (NAMS) Young Membrane Scientist Award in 2018. | |
