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, April 19, 2021

12:00 PM

via

Blue Jeans Video Conferencing

https://bluejeans.com/5255507328

will be held the

DISSERTATION DEFENSE

for

Michelle 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 such as flexible electronics, wearable sensors, and molecular sieving membranes. However, their mechanical and functional performance is not up to theoretical predictions due to a gap in understanding fundamental interactions between the biopolymeric and synthetic components of multilayered composite films. This work will focus on chemical and morphological changes of structural proteins in intimate contact with two-dimensional nanofillers when exposed to differing chemical environments and the resulting mechanical and conductive properties of multilayers composites.

The first task aims to unveil the mechanisms behind silk fibroin’s natural morphological reorganization in direct contact with the surface of Ti3C2Tx MXene over time in aqueous solution. In the second task, the mechanical properties of silk-MXene multilayered composite films were investigated. Finally, suckerin-12 protein encapsulated MXene flakes are fabricated and their morphological reorganization in response to salt annealing was studied. These studies showed that MXene can be uniformly encapsulated by proteins with secondary structures that can be manipulated with non-covalent methods. Organized layered nanocomposites formed from these hybrid materials display enhanced mechanical properties dependent upon protein concentration and secondary structure.

This work will inspire the fabrication of functional bionanocomposites with tailorable properties facilitated through interfacial interaction manipulation via non-covalent methods. These studies provide a framework for understanding interfacial interactions between structural proteins and two-dimensional synthetic materials and outlines techniques with which functional organized protein composites can be designed.