Date of Completion

7-31-2020

Embargo Period

7-31-2022

Keywords

biomaterial, graphene, protein, molybdenum disulfide, low-shear

Major Advisor

Dr. Challa V. Kumar

Associate Advisor

Dr. Rajeswari Kasi

Associate Advisor

Dr. Jie He

Associate Advisor

Dr. Fatma Selampinar

Associate Advisor

Dr. Steven Suib

Field of Study

Chemistry

Degree

Doctor of Philosophy

Open Access

Open Access

Abstract

Herein, the development of high-quality, biophilic two-dimensional nanosheets for use in a diverse array of applications is discussed. Significantly, a potentially universal method for producing nanosheets from their layered crystal counterparts was developed using proteins as dispersing agents. The shearing mechanism was systematically studied and optimized leading to a better understanding of how to prepare these nanosheets for applications as advanced biomaterials.

High concentrations of low-defect, graphene nanosheet suspensions in water (bGr) (10 mg mL-1) were produced using bovine serum albumin as the dispersant in a continual flow reactor, allowing for nearly 100% conversion of graphite to graphene with little to no human intervention. The simplicity of the exfoliation method allowed for the study of optimal graphene production conditions affording important physical insight into the mechanisms of shear induced exfoliation of graphite and other layered crystals.

The ease of production of these high quality bGr suspensions in water allowed for the production of large quantities of the nanosheets for practical applications. For example, graphene coatings were developed to construct precision radiators for outer space solar arrays, coatings for signal enhancement for surface plasmon resonance spectroscopy, and as biocompatible scaffolds for increased enzyme stabilization in protein hydrogels.

Our modular exfoliation method was tested for the production of nanosheets from various other layered crystals including molybdenum disulfide, leading to the development of a one-pot production method of hybrid MoS2/graphene nanosheet suspensions in water. The production of these hybrid suspensions has been systematically optimized, and these novel hybrids have been tested for use in the construction of flexible and bioabsorbable, next generation Zn-air batteries.

These studies provide a novel path towards the engineering of inexpensive, biodegradable advanced technologies such as batteries, radiators, biosensors and light-weight electronics.

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