Off-campus Michigan Tech users: To download campus access theses or dissertations, please use the following button to log in with your Michigan Tech ID and password: log in to proxy server

Non-Michigan Tech users: Please talk to your librarian about requesting this thesis or dissertation through interlibrary loan.

Date of Award


Document Type

Campus Access Dissertation

Degree Name

Doctor of Philosophy in Chemistry (PhD)

Administrative Home Department

Department of Chemistry

Advisor 1

Patricia A. Heiden

Committee Member 1

Loredana Valenzano

Committee Member 2

Shiyue Fang

Committee Member 3

Dana L. Richter

Committee Member 4

Reza Shahbazian-Yassar


Environmental, economic and political forces are increasing interest in transitioning to a sustainable, biobased economy. A major component of such an economy will be replacing petroleum-based materials with biobased materials. Biomaterials are being extensively researched to replace all or parts of petroleum-sourced materials in composites and fibers. Composite materials consist of a reinforcement (fibers or particles) dispersed within a polymer matrix. Composite properties depend on the reinforcement, the matrix, and the interface between them. Fibers are used as reinforcements in composites, or used by themselves as filtration media, fabrics, ropes etc. There are several inherent differences between petroleum-derived polymers and biopolymers. One of these fundamental differences is that Nature has designed biopolymers to biodegrade, which in one respect is advantageous, but it is economically imperative that biobased materials not biodegrade before their intended useful lifetime. Also, many biobased materials (e.g. wood and rice husks) are not compositionally as well as structurally heterogeneous, which means that the mechanical properties of the materials are not spatially uniform. While biobased materials must be designed with these differences in mind, the properties and opportunities for biobased materials are significant. This research investigated a unique interface modification between rice husk reinforcement and a polymer matrix to test the hypothesis that an amphiphilic interface could both reduce (detrimental) moisture uptake of the biobased reinforcement and increase composite properties. This unique interface was able to accomplish both objectives simultaneously but appears to do so for more complex reasons than originally hypothesized. A second investigation synthesized and evaluated new cellulosic nanofiber membranes to remove pathogens and pollutants from water. Microcrystalline cellulose was modified with guanidine hydrochloride via covalent and ionic bonds and electrospinning and crosslinking techniques yielded distinctive nanofiber membranes. Both nanofibers were highly effective at adsorbing enveloped and non-enveloped viruses from drinking water. Due to their size viruses are difficult to separate by filtration, but these materials may provide a relatively inexpensive route to purify drinking water in areas without treatment plants. A third preliminary study looked at new partially or completely biobased polyurethanes to investigate various property effects and Life Cycle Assessments to evaluate environmental impact differences, which are a major driving force to create “greener” products.