Design rules for soft materials: Insights from precision bottlebrush polymers

Author

Michael R. Dearman, Louisiana State University and Agricultural and Mechanical CollegeFollow

Degree

Doctor of Philosophy (PhD)

Department

Gordon A. and Mary Cain Department of Chemical Engineering

Document Type

Dissertation

Abstract

The rational design of soft materials requires a fundamental understanding of how molecular architecture governs macroscopic properties. This dissertation establishes predictive design rules for branched soft materials by exploiting the structural homogeneity of precision bottlebrush polymers (dispersity_SC, Đ_SC = 1.0). Using discrete macromonomers (Đ = 1.0) to eliminate side chain dispersity, this work systematically varies backbone and side chain lengths, chemistry, and topology to uncover universal relationships between molecular parameters and thermal or interfacial behavior. A critical backbone length (N_BB^*) is identified, above which glass transition temperature (T_g) becomes independent of backbone extension, while side chain stiffness and flexibility mismatch (ζ) dictate T_g scaling across chemical families. These findings culminate in a modified Flory-Fox framework that collapses experimental and simulation data onto master curves, enabling inverse design of polymers with targeted thermal response. Beyond thermophysical insights, the study demonstrates how architectural precision programs assembly at interfaces, linking nanoscale order to macroscopic material performance. Collectively, these results transform bottlebrush polymers from structural curiosities into quantitative models for establishing general design principles in soft matter.

Date

11-3-2025

Recommended Citation

Dearman, Michael R., "Design rules for soft materials: Insights from precision bottlebrush polymers" (2025). LSU Doctoral Dissertations. 6957.
https://repository.lsu.edu/gradschool_dissertations/6957

Committee Chair

Lawrence, Jimmy