MechE PhD Prospectus Defense: Yuanzhi Li

TITLE: Nanostructured Organogels from Self-Assembled and Crosslinked Block Copolymers

ABSTRACT: Despite decades of research on block copolymer self-assembly and covalent poly- mer gels, soft gels with spatially defined mesoscale distribution of chemical activity that guide and accelerate reactions by chemical nanoconfinement are inadequately studied. My current research is based on a rationally designed triblock terpolymer system with one block that is selectively crosslinked at tunable crosslinking density after self-assembly. Remarkably, upon free swelling in solvents, various distinct nano-morphologies including hexagonally packed cylinders and two gyroidal three-dimensionally periodic network structures exhibit macroscopic and nanoscopic structural integrity proven by small-angle X-ray scattering and transmission electron microscopy. Since these ordered organogels present a novel class of solvent-laden bulk materials that ex-hibit chemically distinct nano-environments on a periodic mesoscale lattice, we demon-strate the use of selective infusion templating for nano-confined synthesis of poly(acrylonitrile) from which a monolithic ordered mesoporous carbon is obtained via removal of template and carbonization of poly(acrylonitrile). Moving forward, we envision the soft gels to enable the fabrication of more traditionally hard-to-template materials as nanostruc-tured monolithic metamaterials that possess novel mechanical and optical properties.

COMMITTEE: ADVISOR/CHAIR Professor Joerg G. Werner, ME/MSE; Professor Keith Brown, ME/MSE/Physics; Professor William Boley, ME/MSE; Professor Abigail Plummer, ME/MSE