RII Track-4: Linking Chemistry to the Mechanics of Dynamic Hydrogel Interfaces

University Of Kentucky Research Foundation, Lexington KY

Investigators

Abstract

Non-Technical Description Soft hydrogel interfaces are essential for high-technology applications, from synthetic tissues and medical adhesives, to commodity products, such as contact lenses. However, the majority of hydrogels are limited to static properties, hindering advanced material functions. This award supports fundamental research that aims to advance knowledge on how to control dynamic interfaces enabled by dynamic bonds in hydrogels, and relate macroscopic to microscopic mechanical behavior. The project takes advantage of expert resources and facilities at the Massachusetts Institute of Technology (MIT), where the PI and his collaborators will focus on synthesizing new dynamic hydrogels and characterizing their mechanical properties. The resources available in soft matter at MIT will play a critical role in synthesis and characterization of these hydrogels. In addition to advancing scientific knowledge, successful development of dynamic hydrogels is expected to afford a platform for new biomaterials to advance national health. New lasting collaborations will be developed between the PI and hosts, which will strengthen partnerships between the University of Kentucky (UK) and MIT, leading to a stronger program in soft materials at UK. Technical Description Soft polymer interfaces underpin many important applications, from hydrogel medical adhesives and synthetic tissues to contact lenses. However, they are largely limited to materials with static properties, hindering advanced functions where smart, responsive, or transient interfaces are desirable. The proposed research aims to advance our knowledge on how to control interfaces of soft hydrogels with dynamic properties, enabled by ligand-metal crosslinking dynamics. We expect interfacial behavior to be governed by the time-dependent formation of bonds, near-surface viscoelasticity of the bulk material, and the molecular architecture and composition of the gel relative to the crosslinking dynamics. To address this hypothesis, the PI will cultivate lasting collaborations with experts at the Massachusetts Institute of Technology (MIT) in hydrogel synthesis with metal-ligand crosslinking and non-Newtonian mechanical characterization. As part of this project, the PI and a student will be trained in necessary synthesis methods, as well as unique rheological methods. The results obtained on the chemistry and macroscale rheology will be coupled with interfacial mechanics experiments to develop a link between the chemistry and mechanics of dynamic hydrogel interfaces. The skills gained by the PI will become extremely valuable as new chemistry and molecular organizations are explored to expand the versatility and control of dynamic hydrogel properties. 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.