Description:

The Department of Chemical and Biological Engineering is pleased to present a seminar by Cécile Chazot, Assistant Professor of Materials Science and Engineering at Northwestern.

Cécile Chazot will present a seminar titled "From Molecular Form to Macroscale Function in Chiral Biopolymers." 

ABSTRACT: Chiral biopolymers such as polysaccharides and polypeptides possess intrinsic molecular features (backbone stiffness, chirality, and tunable chain dynamics) that enable hierarchical self-assembly into liquid crystalline (LC) phases with emergent optical and mechanical properties. However, most of these self-assemblies have been uncovered in biological systems or serendipitously in polymeric solutions, with limited efforts to purposefully control molecular architecture to tailor hierarchical order or dynamically tune LC behavior through molecular transformations.

Here, I will describe our work in understanding how molecular form drives multiscale ordering, and how chemical reactivity can be harnessed to program adaptive functionality across length scales in biopolymeric materials. Using wool keratin as a natural model system, I will describe how my group mapped the relationship between sulfur content, protein secondary structure, intermediate filament packing, and fiber mechanics; thereby establishing design principles that link molecular architecture to macroscale function in natural systems. I will then describe how we control the formation of cholesteric LC domains in biopolymer solutions based on soluble polysaccharides, such as chitosan and cellulose ethers, revealing how molecular weight and pendant group chemistry govern LC phase behavior, selective reflectivity, and stimuli-responsive circular dichroism.

Beyond passive self-assembly, I will highlight our efforts in chemically augmenting biopolymer functionality for dynamic properties through scalable substitution chemistry. I will show how introducing photoswitchable side chains enables reversible modulation of conductivity and photonic bandgaps via isomerization, expanding the stimuli-responsive behavior of these LC mesophases beyond conventional triggers like heat, composition, and mechanical stress. These transformations couple molecular reactivity to LC domain orientation and optical response, creating materials whose properties are reversibly and dynamically tunable.

By integrating hierarchical self-assembly with targeted chemical modification, our work establishes a framework for designing sustainable soft materials in which function is encoded in structure and activated through molecular transformation. These insights have direct implications for the development of next-generation natural fibers and textiles with programmable optical, mechanical, and environmental responsiveness.

Cécile A. C. Chazot is the Julia Weertman Assistant Professor of Materials Science and Engineering at Northwestern University, where she leads the Sustainable Polymer Innovation Laboratory (SPIn Lab). Since joining Northwestern in January 2023, her research has focused on developing scalable and environmentally responsible polymer processes for textile manufacturing and recycling. Her lab combines fundamental biopolymer design with advanced materials processing to uncover and control structure–property–processing relationships in natural polymers, with applications in stimuli-responsive fibers, films, and circular textile systems. Cécile earned her Ph.D. in Materials Science and Engineering from MIT in 2022, under the supervision of Prof. A. John Hart, and holds an M.Sc. in Materials Science and Engineering from Mines ParisTech in France. She is also a co-founder of the Materials Initiative for Comprehensive Research Opportunity (MICRO), a remote research program designed to expand access to materials science research for undergraduates across the U.S. Her work at the intersection of biopolymer innovation and fiber-based materials has earned her several recognitions, including the Army Research Laboratory Early Career Award, designation as an ACS Materials Au Rising Star in Materials Science, and selection as an RSC Applied Polymers Emerging Investigator, all in 2025.

Bagels will be served at 9:30 and the seminar will start around 9:40am.