Paper Number
SM37
Session
Polymers Solutions, Melts and Blends
Title
Retaining structural color in a diblock bottlebrush copolymer solution by chemical and physical means
Presentation Date and Time
October 12, 2022 (Wednesday) 10:30
Track / Room
Track 2 / Sheraton 3
Authors
- Wade, Matthew A. (University of Illinois Urbana-Champaign, Chemical and Biomolecular Engineering)
- Shi, Jiachun (University of Illinois Urbana-Champaign, Department of Chemical and Biomolecular Engineering)
- Kamble, Yash (University of Illinois Urbana-Champaign, Chemical and Biomolecular Engineering)
- Walsh, Dylan (Massachusetts Institute of Technology, Chemical Engineering)
- Guironnet, Damien (University of Illinois Urbana-Champaign, Chemical and Biomolecular Engineering)
- Rogers, Simon A. (University of Illinois at Urbana-Champaign, Department of Chemical and Biomolecular Engineering)
Author and Affiliation Lines
Matthew A. Wade, Jiachun Shi, Yash Kamble, Dylan Walsh, Damien Guironnet and Simon A. Rogers
Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801
Speaker / Presenter
Wade, Matthew A.
Keywords
additive manufacturing; gels; microscopy; polymer blends; polymer solutions
Text of Abstract
The formation of structure-property-processing relations for polymeric materials has been of interest from an industrial, biological, and fundamental academic perspective. In the field of direct ink writing and the development of smart inks, the structure-property-process relations exhibited by diblock bottlebrush polymers in solution have garnered recent interest due to the ability to tune the material’s microstructure, and thus bulk color, through the application of shear. However, the short relaxation time of diblock bottlebrushes has made it difficult to preserve microstructure and color induced through deformation. Two avenues for increasing the relaxation time of diblock bottlebrush polymer solutions and thus retain the shear induced microstructure have been explored. In-situ UV curing was carried out on a functionalized polylactic acid-b-polystyrene bottlebrush copolymer and dispersed in toluene at 5 °C forming a solution with a concentration of 175 mg/ml. Photo initiator and a thiol group were added to the solution to promote crosslinking between functionalized polymers when exposed to UV radiation. As an alternative to UV curing, changes to sample composition to increase the relaxation time to were explored. Doubling the concentration of the bottlebrush in toluene as well as swapping the solvent of the sample to m-xylene resulted in solutions that were found to exhibit yield-like behavior. Using recovery rheology concepts, we can identify when the material begins to yield and exhibit more liquid-like behavior as well as when structures reform and the bulk displays more solid-like behavior again. The two approaches we present can therefore be used in the rational design of smart inks for direct ink writing that retain desirable structures induced by high shear printing processes.