RUI: Solution and Thin Film Properties of Dually Stimuli-Responsive Molecular Brush Block Copolymers

University Of Wisconsin-Eau Claire, Eau Claire WI

Investigators

Abstract

NON-TECHNICAL SUMMARY Understanding the fundamental relationships between a polymer's molecular structure and its observed properties allows customizing of the properties for possible applications. A polymer known to dramatically change properties, like the ability to dissolve in water, in response to a small change in an external stimulus, such as temperature and pH, has been selected for detailed investigation. By changing the structure of this polymer to create comb-like of bottlebrush-like molecular architectures from this core polymer and to add chemically distinct segments, it is expected that new polymeric materials will be generated with unique properties both in solution and in thin films. The properties of these polymeric materials can be tailored for potential applications with benefit to society such as polymers for water purification and better targeted and customized drug delivery. These materials will be prepared using a more environmentally benign synthetic approach. New knowledge generated from this work will be shared with a broad scientific audience through publications, presentations, and incorporation into the undergraduate curriculum, and to more general audiences through community and K-12 outreach presentations. This project will provide full-time immersive research experiences for undergraduate students, particularly for women in materials science and engineering. This will encourage more women to pursue advanced degrees and research careers in science and engineering. TECHNICAL SUMMARY The objective of this project is to determine the effect of combining block and branched copolymer architectures with stimuli-responsive properties for the self-assembly of copolymers in solution and in thin films. The stimuli-responsive functionality results in dramatic changes in properties, such as solubility, viscosity, viscoelasticity, interfacial activity, and self-assembly, with a small change in external stimuli. Branched and block copolymer structures affect polymer properties including polymer conformation, chain entanglement behavior, self-assembly, and rheological responses. Stimuli-responsive copolymers with block and branched architectures will be synthesized using the more environmentally benign activator regenerated by electron transfer atom transfer radical polymerization (ARGET ATRP). The pH- and thermo-responsive poly((2-dimethylamino)ethyl methacrylate) (PDMAEMA) has been selected as the primary stimuli-responsive polymer under investigation because it changes solubility and conformation in response to changes in both temperature and pH. The stimuli-responsive functionality of PDMAEMA will be combined with block and branched copolymer architectures in order to generate new materials with expected unique solution and thin film properties. These materials have potential applications in photonics, drug delivery, and viscosity modifiers, including applications that have benefit to society such as polymer membranes for water purification and more tailored drug delivery systems. Undergraduate student research collaborators will fully participate in this immersive high impact experience of undergraduate research. This is expected to increase the retention of undergraduate women in materials science and engineering at the University of Wisconsin-Eau Claire and to encourage more women to pursue advanced degrees and research careers in STEM. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.