Date of Award


Document Type


Degree Name

Doctor of Engineering (DEng)


Chemical and Biomolecular Engineering

Committee Chair/Advisor

Christopher Kitchens

Committee Member

David Bruce

Committee Member

Mark Thies

Committee Member

Mark Roberts

Committee Member

O. Thompson Mefford


Biomass is vital to ongoing efforts to secure a sustainable future. While many of our efforts focus on finding alternative forms of energy, biomass among them, only biomass has the potential to serve as a sustainable materials feedstock. However, biomass is heterogenous, complicating the upgrading processes needed to manufacture commodity and performance products. For example, plant biomass consists largely of cellulose, a crystalline polysaccharide, and lignin, a highly stable polyaromatic. The specific properties of cellulose and lignin depend greatly on the plant, harvesting conditions, and isolation procedures. Thus, accurate and reliable determination of the fundamental properties of biomass is crucial to downstream valorization efforts and the progression toward sustainability goals. Here, we develop and refine new methods for characterizing lignin. Specifically, the work described herein examines various optical interference phenomena and their role in lignin molar mass determination. These efforts led to the developing of a correction procedure that accurately measures the absolute molar mass of lignin polymers using traditional analytical methods. This new technique was validated using a well-characterized model protein system, and only then was it used to analyze lignin systems. We have conducted several studies proving the robustness of the new protocol in many different experimental settings. These studies demonstrated that this new characterization method is the most robust and accurate for determining lignin molar mass. This new fluorescent characterization technique for elucidating the size of dispersed macromolecules resolves longstanding problems with lignin characterization and may prove vital to our understanding and future efforts to produce lignin-based renewable materials.

Author ORCID Identifier




To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.