Talk given by
Prof. Michael A. Pope
Department of Chemical Engineering and
Waterloo Institute of Nanotechnology
University of Waterloo
Abstract: Graphene and related 2D nanomaterials are expected to revolutionize many applications due to their unique optical, electronic and mechanical properties. These atomically thin sheets are typically micron to submicron-sized in lateral extent when exfoliated from bulk precursors and must be controllablyassembled into large area films or coatings to form functional nanocomposites. Graphene-based materials hold significant promise for applications such as rechargeable batteries and supercapacitors which require electrodes with high surface area and controlled porosity while, on the other hand, they can also be processed into non-porous or selectively permeable membranes for applications such as water desalination. Engineering materials which traverse these seemingly conflicting abilities depend largely on how we manipulate their colloidal assembly and aggregation behavior during processing.
In this talk, I will discuss some of the innate processing challenges associated with the fabrication of porous and non-porous films from 2D materials obtained by the exfoliation of bulk precursors. I willthen describe several new methods being developed in my laboratory to address or by-pass these challenges in the context of enabling both higher performance energy storage devices as well as improved thin film membranes which can be used in applications ranging from lithium anode protection to desalination. Towards the development of improved supercapacitors and lithium-sulfur batteries, I will highlight recent work that uses colloidal co-assembly strategies to intimately combine active materials into dense, high surface area graphene networks. On the other hand, to create dense blocking layers, membranes and heterostructures, I will discuss a new monolayer film deposition method which utilizes the air-water interface and liquid-liquid spreading to enable continuous film growth and transfer. Finally, I will discuss recent work that investigates the use of laser-conversion of commercial and custom-designed polymers to make patterned, high surface area electrodes for miniaturized and flexible electrochemical devices using simple imbibition and heterogeneous nucleation and growth processes.
Bio Sketch: Prof. Pope is an Assistant Professor in the Department of Chemical Engineering who began his research program at the University of Waterloo in September 2014. He obtained his PhD from Princeton University where he studied the production and processing of graphene-based materials into advanced batteries and supercapacitors. During his post-doctoral work at Vorbeck Materials Corp., a large-scale graphene producer, he was the technical lead on a developmental program to commercialize Li-S batteries, he built and operated a pilot-scale fiber spinning line for producing high strength graphene-filled polyesters and contributed to Vorbeck’s graphene ink development. His group is currently focused on developing nanocomposites from a variety of 2D materials for applications ranging from energy storage and electrocatalysis to water purification.