Paper Number
SM24
Session
Polymers Solutions, Melts and Blends
Title
Direct visualization of single comb polymer dynamics in semi-dilute solutions: Complex interplay of topology and concentration at the molecular scale
Presentation Date and Time
October 22, 2019 (Tuesday) 3:45
Track / Room
Track 3 / Room 201
Authors
- Patel, Shivani Falgun (University of Illinois at Urbana-Champaign, Chemical and Biomolecular Engineering)
- Schroeder, Charles M (University of Illinois at Urbana-Champaign, Chemical and Biomolecular Engineering)
Author and Affiliation Lines
Shivani Falgun Patel and Charles M Schroeder
Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801
Speaker / Presenter
Patel, Shivani Falgun
Text of Abstract
Topologically complex polymers such as branched polymers form the cornerstone of modern technology and advanced materials. Despite their increasing importance, our current understanding of the non-equilibrium dynamic behavior of these topologically complex polymers is limited and is largely based on and limited to bulk rheological and experimental scattering data, theories and simulations. Owing to their complex molecular architectures, comb-shaped polymers exhibit rich dynamic behavior that is not fully understood at the molecular level. To address this, we study the dynamics of single branched polymers in non-dilute solutions using single-molecule fluorescence microscopy (SMFM). In particular, we use a hybrid enzymatic-synthetic approach to synthesize DNA-based branched polymers (comb polymers) that contain a long backbone with multiple side branches grafted at various positions. The backbone and branches are dual-labeled to allow their long-time simultaneous but separate imaging. Following synthesis, we directly study the relaxation and transient stretching dynamics of single comb polymers in unentangled semi-dilute solutions of linear unlabeled polymers in extensional flow. These dynamics are then compared to the dynamics of comb polymers in ultra-dilute solutions, and linear polymers in non-dilute solutions. Interestingly, the dynamic behavior of comb polymers is markedly different in non-dilute polymer solutions, which reveals changes in molecular-scale dynamics due to chain branching and chain-chain intermolecular interactions. We further study the effects of background concentration and polymer topology on comb polymer dynamics in order to elucidate the non-equilibrium behavior of topologically complex polymers in hitherto unexplored concentration regimes. Overall, our work shows that single polymer dynamics can be used to provide a direct link between polymer microstructure and bulk rheological properties.