PhD Defense by Collen Leng
THE SCHOOL OF MATERIALS SCIENCE AND ENGINEERING
GEORGIA INSTITUTE OF TECHNOLOGY
Under the provisions of the regulations for the degree
DOCTOR OF PHILOSOPHY
on Thursday, August 30th, 2018
in Love 210
will be held the
"Hybrid Organic-Inorganic Materials Synthesized via Vapor Phase Infiltration"
Prof. Mark Losego, Advisor, MSE
Prof. Karl Jacob, MSE
Prof. Zhiqun Lin, MSE
Prof. Matthew McDowell, ME/MSE
Prof. Samuel Graham, ME
Polymers are used in a wide range of applications, from high-tech devices to everyday products, yet they suffer from limitations such as low chemical stability and mechanical strength. By incorporating inorganic constituents into these materials, we can bring about the best of both worlds in terms of new properties that might not be offered by either material alone.
This thesis presents a processing theory created from experimental measurements to allow precise control of vapor phase infiltration (VPI) used to create new organic-inorganic hybrid materials. VPI works by allowing metalorganic precursors commonly used in chemical vapor deposition to diffuse into polymers and react with polymer functional groups or co-reactants at low processing temperatures (below 200 Celsius). This process can transform nanometers to microns of polymer into hybrid material. While several research groups have explored various materials properties of VPI-modified polymers, the research community still does not understand the exact processing kinetics and thermodynamics of VPI. By using ex situ and in situ characterization techniques, we have calculated energy parameters for VPI processing kinetics and thermodynamics for the classic trimethylaluminum and poly(methyl methacrylate) system. This thesis also presents new properties in the hybrid materials including chemical stability and water absorption that can give more insight into what the materials can transform into through VPI.