The Chemical and Biological Engineering Department proudly presents a student seminar by Tyler Heyl, titled "Correlative Nanomechanical Mapping and Super-Resolution Microscopy to Investigate Local Properties in Interpenetrating Polymer Networks."

ABSTRACT: Compatibilization in multi-component polymer systems is a strategy to combine immiscible polymers without macrophase separation, which otherwise results in opaque and fragile polymer blends. One strategy to compatibilize polymers is forming interpenetrating polymer networks (IPNs). IPNs combine hard and soft materials into tough, elastic networks. Macroscopic structure-property relationships are sought after for these system, but currently methods fail to capture the local detail needed to fully understand mechanical reinforcement and phase separation. To fill this need, we investigated the relationship between local modulus and composition by correlating nanomechanical mapping (NM) with single-molecule localization microscopy (SMLM) in poly(dimethylsiloxane)/poly(methyl methacrylate) (PDMS/PMMA) IPNs. Imaging the same sample areas with NM and SMLM allowed us to measure and relate the modulus (from NM) and composition (from SMLM) on a nanometer-length scale. We discovered domain-to-domain differences in modulus and composition and established that these could be related through the rule of mixtures for modulus. Then, by examining the relationship between domain size and composition, we proposed a phase separation mechanism for PDMS/PMMA IPNs cured simultaneously. Overall, combining these two methods to measure the local mechanical properties and composition results in a level of microstructural understanding that has not been previously achieved.

Bagels and coffee will be provided at 9:30am, and the seminar will start at 9:40am. Please plan to arrive on time to grab a bagel and mingle!

*Please note that there will be no Zoom option for seminars this year.