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 15, 2019

12:45 PM
in MRDC 3515

will be held the

DISSERTATION PROPOSAL DEFENSE

for

Pedro J. Arias-Monje

"Advanced Dispersion Strategies of Carbon Nanotubes and their use for Reinforcement of Nanocomposite Polymer Fibers"

Committee Members:

Prof. Satish Kumar, Advisor, MSE

Prof. Karl Jacob, MSE

Prof. Hendrik Heinz, ChBE, UCB

Prof. Kyriaki Kalaitzidou, ME

Prof. Suresh Sitaraman, ME

Prof. Naresh Thadhani MSE

Abstract:

Carbon nanotubes (CNT) have attractive inherent mechanical properties: tensile strength and modulus ~100 GPa and ~1 TPa, respectively and density typically lower than 1.8 g/cm3. However, most studies show that self-standing CNT macrostructures and CNT nanocomposites have relatively low mechanical properties. Commonly, failure to produce high performance continuous macroscopic materials from CNT is due to i) low CNT individualization, ii) low CNT orientation, and iii) low interfacial shear strength (IFSS) between nanotubes and the composite matrix, at high CNT loading.

The proposed research focuses on studying, a) strategies for CNT dispersion in organic solvents and improving IFSS in the composite, and b) the processing, structure and properties of nanocomposite polymer fibers with high loading of CNTs. Two different experimental strategies will be investigated to reach this goal. The first one consist of ordered helical wrapping of individual single wall carbon nanotubes (SWNT) with poly(methyl methacrylate). The second one is based on SWNT dispersion aided by co-solvents of low molecular weight. Both strategies are based on non-covalent interactions of pristine SWNT with the polymer and the co-solvents. Following these approaches, SWNTs without functionalization can be used, preserving the properties of the nanomaterial.

Preliminary results indicate that good dispersions can be achieved by either strategy or by combining them. Furthermore, poly(acrylonitrile-co-methacrylic acid) fibers with up to 5 wt. % SWNT have been produced after following dispersion by helical wrapping. Processing, structure, and properties of these fibers were studied and compared to similar nanocomposite fibers processed without PMMA wrapping.