Our research goal is to design polymers with new capabilities – ones that autonomously improve their performance as a response to distinct energy inputs. In the past, it was almost universally understood that excess energy degrades polymers. For example, UV rays in sunlight can degrade polymers or mechanical force can cleave polymer chains. Our research program will use mechanical energy to strengthen polymeric materials instead.
Specifically, we are designing polymers that can undergo self-strengthening when they experience mechanical force. To achieve this we will develop mechano-responsive polymers that, under mechanical activation, will promote the formation of new polymeric structures. We will use these mechano-responsive polymers to fabricate force-activated polymeric adhesives (useful in additive manufacturing), develop force-activated polymeric foams that are deployed after mechanical impact (useful in automotive and defense sectors), and promote force-activated self-healing in polymers (useful to extend lifetime of consumer plastics).
Mechanically Controlled Radical Polymerization Initiated by Ultrasound by Mohapatra H., Kleiman M. , Esser-kahn A. P. Nature Chemistry 9 135-139 (2017)
Stimuli-Responsive Polymer Film that Autonomously Translates a Molecular Detection Event into a Macroscopic Change in Its Optical Properties via a Continuous, Thiol-Mediated Self-Propagating Reaction by Mohapatra H., Kim H. , Phillips S. T. Journal of the American Chemical Society 137 12498-12501 (2015)