THE SCHOOL OF MATERIALS SCIENCE AND ENGINEERING

GEORGIA INSTITUTE OF TECHNOLOGY

Under the provisions of the regulations for the degree

DOCTOR OF PHILOSOPHY

on Monday, May 13, 2019

2:00 PM
in MoSE 1201A

will be held the

DISSERTATION PROPOSAL DEFENSE

for

Mechelle Krecker

"Interfacial Assembly of Natural and Synthetic Components for Functional Bionanocomposites"

Committee Members:

Prof. Vladimir Tsukruk, Advisor, MSE

Prof. Valeria Milam, MSE

Prof. Satish Kumar, MSE

Prof. Eric Vogel, MSE

Dhriti Nepal, Ph.D., AFRL

Abstract:

Organized bionanocomposites are promising new materials since they are biocompatible, biodegradable, and can be used in a variety of applications. However, their mechanical and functional performance is not up to theoretical predictions due to a gap in understanding fundamental interactions between components. For instance, biopolymeric enhanced adhesion at the interface between components could mediate slippage and separation, changing a brittle graphene oxide paper into an ultra-robust and flexible nanocomposite. This work will focus on studying the chemical and morphological changes at the interface between biopolymers and 2D nanofillers under different chemical and mechanical conditions for the eventual use in organized bionanocomposites.

The first task aims to unveil the mechanisms behind silk fibroin’s natural morphological reorganization in direct contact with Ti3C2Tx MXene surface over time in aqueous solution and with directed organization via methanol-mediated annealing. In the second task, the morphology, adhesion, and mechanical properties of combined nanocellulose structures and MXenes flakes will be studied with and without the assistance of adhesive trihydroxyphenethylamine modification. Finally, interfacial interactions between graphene oxide and MXenes with various biopolymeric surface modifications will be investigated singularly and combined in laminated bionanocomposites. Buckling mechanical tests will be used in conjunction with various characterization methods including atomic force microscopy (AFM) and Fourier transform infrared spectroscopy (FTIR) to determine mechanical properties, morphology, and chemical changes between natural and synthetic components.

This work will inspire the fabrication of robust and functional bionanocomposites with tailorable properties facilitated through interfacial interaction information obtained in this study. This knowledge will expand bionanocomposite functionality by tailoring structure-property relationships to optimize mechanical, optical, and electrical characteristics for specific applications. This work will lead to a new class of materials that are both flexible and robust while simultaneously hosting advanced properties of its constituent components such as electrical conductivity from the 2D components and bio-responsive properties from the biological components.