Daphne Wui Yarn Chan, Assistant Professor, Carnegie Mellon University

"Proteins as renewable reinforcing components in copolymers and composites"

Abstract:

Polymers are ubiquitous in modern society, playing important roles in providing essential functionality across a wide range of applications from everyday plastics to advanced materials. However, growing concerns over the environmental impact of fossil fuel-derived polymers have intensified the search for sustainable alternatives. Biopolymers such as proteins offer a compelling opportunity due to their renewability, biodegradability, and rich chemical functionality. 

Our group seeks to bridge the gap between bio-based and conventional synthetic polymers by leveraging protein self-assembly and bioconjugation strategies to create mechanically robust, processable materials. We are developing protein modification and polymerization approaches to fabricate elastomers and composites in which proteins act as active reinforcing components. Using free-radical polymerization, we demonstrated that proteins can be copolymerized with rubbery polymers to produce materials with high strength and toughness. By controlling copolymer architecture and incorporating dynamic covalent bonds, these materials can be melt-processed, enabling reprocessability and recyclability.

In parallel, we are exploring the reinforcing potential of protein-based nanofibrils in copolymers and composite materials. These nanofibrils possess a characteristic cross-β structure that imparts exceptional mechanical stability. We prepared nanofibrils from agricultural proteins through controlled heating and acidification, and we probe their structure and chemical reactivity to enable effective integration into polymer matrices. By establishing clear structure-property-processing relationships across these systems, we aim to advance a platform for materials that combine the performance of polymers with the renewability of proteins.

Bio:

Daphne Chan is an assistant professor in the Department of Chemical Engineering at Carnegie Mellon University. She received her B.S. in Chemical and Biomolecular Engineering from Johns Hopkins University in 2013 and her Ph.D. in Chemical Engineering from Massachusetts Institute of Technology (MIT) in 2019, where she was a recipient of the MIT Tata Center for Technology and Design Fellowship. She subsequently earned the University of Minnesota’s President’s Postdoctoral Fellowship. Her research focuses on the design of sustainable and functional polymeric materials, including renewable protein-based copolymers and composites, block copolymer self-assembly, protein nanofibril self-assembly, and stimuli-responsive materials for soft robotics. A unifying theme of her work is the control of intermolecular interactions and hierarchical self-assembly to tailor microstructure and material performance.