Chemical Determinants of Complexation in Polyelectrolyte Complexes and Coacervates

University Of Pittsburgh, Pittsburgh PA

Investigators

Abstract

In this project funded by the Macromolecular, Supramolecular and Nanochemistry Program in the Division of Chemistry, Prof. Jennifer Laaser's research team at the University of Pittsburgh will investigate how changes in specific chemical features of charged polymers, such as inclusion of hydrophobic chemical components that do not want to mix with water, affect the properties of these materials. Her team will then develop methods for rapidly identifying the combination of chemical features that will generate the physical properties needed for any given application. This research will provide new fundamental insight into how different chemical interactions affect the behavior of charged polymer mixtures and inform development of new functional materials. Mixing positively and negatively charged polymers in water leads to formation of materials with a wide range of uses in medicine and consumer products. These materials can be either liquid-like or solid-like. Understanding how to control their solubility and physical properties is important for making materials that can meet the needs of new applications. This project will provide training opportunities for graduate and undergraduate students and serve as the foundation for both new teaching materials for college courses in polymer science and outreach activities in the local community. These teaching materials will incorporate application-oriented activities in which students will apply fundamental chemistry and physics knowledge to make predictions about real-world problems. Dr. Laaser's team will investigate how specific chemical interactions, such as hydrophobic and cation-pi interactions, affect the properties of polyelectrolyte complexes and coacervates by using post-polymerization functionalization to synthesize polymer libraries with well-defined and systematically-varied compositions. The team will use these libraries to investigate how the presence of hydrophobic and aromatic functional groups affects the phase behavior, thermodynamics, and viscoelasticity of complexes of oppositely-charged polymers. The team will then investigate the role of chemical composition in self-coacervating polyampholytes. The new fundamental knowledge developed here is expect to enable precisely targeted properties by of charged-polymer mixtures tailoring the polymer chemistry, rather than solution conditions. 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.