Visualizing molecular structure and function in soft matter using coherent Raman imaging*

Structure-function relationships define the how molecular processes give rise to macroscopic observables. In this talk, I will present an overview of our recent work using nonlinear vibrational spectroscopic imaging to reveal unique structural-function relationships in polymeric soft matter systems. We have used this imaging technology to map protein structure in fibrin biopolymer networks (that lie at the heart of blood coagulation) and demonstrated that fibrin biopolymers change structure in a spatially heterogeneous manner when exposed to tensile, but not shear, loads. This result hints at a unique self-regulating mechanism via a direct biophysical feedback loop in a physiological context. In another project measuring real-time water transport, we have shown that under-coordinated microscopic water transport and macroscopic proton transport are related in nano-structured polymer fuel cell membranes. From these data, we have proposed a strategy to boost efficiency in fuel cell membrane materials.