Available at: https://digitalcommons.calpoly.edu/theses/2754
Date of Award
12-2023
Degree Name
MS in Polymers and Coatings
Department/Program
Chemistry & Biochemistry
College
College of Science and Mathematics
Advisor
Shanju Zhang
Advisor Department
Chemistry & Biochemistry
Advisor College
College of Science and Mathematics
Abstract
A host of environmental issues will define the state of the environment in the 21st century, with plastic pollution and water shortages among them. While solutions to these problems require large-scale, multipronged solutions, one way we can address them is through material innovation and the use of nanoparticles.
In the first project, we address the issue of plastic pollution by creating nanocomposites of biodegradable polymers (PLA and PCL) with cellulose nanofibrils. Here, PLA and PCL are grafted from the surface of cellulose nanofibrils via ring-opening polymerization of cyclic ester monomers. Polymer-grafted cellulose (PGC) is characterized with structural analysis, solubility tests, thermal properties. Graft-polymer and generated free polymer are compared to evaluate assumptions about polymerization kinetics. Lastly, environmental fate of PGC is evaluated via aerobic, anaerobic, and enzymatic biodegradation tests.
In the second project, we address the issue of fresh water shortage by creating screen-printed composites of polymerizable, surfactant-templated single-wall carbon nanotubes (SWNTs). Surfactant-templated SWNTs behave as lyotropic liquid crystals (LLCs), allowing self-assembly and shear-directed alignment. Here, LLC-SWNT inks are screen-printed in micron-sized channels and polymerized with UV light. Mesophase and alignment are evaluated using SAXS. Certain methods of screen printing with a stencil are found to enhance alignment and ordering of LLC-SWNTs, allowing for enhanced desalination and ion rejection.