Graphene and Other Nanosheets: Exfoliation and Processing for Nanocomposites and 3D Macrostructures

Research Background:

The emergence of graphene as a single layer nanosheet with unique properties has paved the way to exploit the optical, electrical, thermal and mechanical properties of other nanosheets such as MoS₂, WS₂, and boron nitride. Many of the existent layered materials have been exfoliated to produce unprecedented nanosheets including Mxenes and black phosphorous. The dependence of the nanosheets properties and potential applications on their structure and morphology, particularly on the number of layers in an individual nanosheet, necessitates a precise control over their production techniques. Current nanosheets exfoliation techniques including the liquid-phase exfoliation lack such a control at atomic level and are challenged by the instability and reaggregation of nanosheets in liquid media. On the other hand, the yield of these techniques is not sufficient for bulk usage of nanosheets in applications such as composites or battery electrodes.  Hence, strategies for scalable, high-yield production of nanosheets that offer atomic-level control over their structure and properties are in high demand.

To this point, in Prof. Micah Green’s laboratory, I have tried to address the low yield of liquid phase exfoliation by using dispersant molecules for stabilization of colloidal graphene at higher concentrations.  I have also tailored the polymer molecules to synthesize polymeric dispersant compatible with pristine graphene, a product with highest quality in graphene family. This allows for the usage of minimal graphene content for mechanical and electrical properties enhancement in polymer nanocomposites. The change of morphology of graphene from 2D nanosheets to 3D crumpled particles is another strategy that I have explored to prevent aggregation during the processing of graphene for other applications. Recently, I have focused on understanding the colloidal interactions in the graphene oxide dispersions in order to control their assembly into 3D macrostructures; ideally, these porous conductive 3D networks could be the optimum electrodes for lithium ion batteries.

Research Interests:

Being aware of the similarities and differences of graphene and other nanosheets, as a faculty member, I will expand my research to new materials and technologies. The research carried in my future laboratory will focus on (i) developing alternative synthesis and/or exfoliation methods for existing and novel 2D nanomaterials, (ii) fundamental study of the processing-structure-property relationships in each nanosheet family, (iii) relate the nanoscale properties of nanosheets to their bulk performance in macrostructures, and (iv) scalable manufacturing strategies to enable usage of these materials in industrial end products in response to real-life needs.

Teaching Interests:

In my laboratory and future classes, I would apply the methodology that I have developed during my research career and my teaching experience as a teaching fellow and teaching assistant (Numerical Analysis for Chemical Engineers & Reaction Design courses)  to create a vivid learning environment for my future students. While they will obtain a fundamental understanding of the physics behind their research topic, they will get the opportunity to use their engineering background to design and build products with industrial applications. Obviously, collaboration with both industrial organizations and academic scientists with different computational and experimental skills is essential to accomplish these goals.