Title :

Mechanochemical strengthening of polymeric materials using piezoelectric nanoparticles

Abstract :

Mechanical actuation of synthetic polymers usually results in bond breakage leading to eventual failure. In contrast, biological systems use mechanical force for constructive purposes. For example, bones and muscles heal and become stronger under moderate levels of stress often encountered during exercise. In this talk, I will present my work towards developing synthetic polymeric materials that grow stronger under mechanical activation.

Mechanical force can be harnessed for performing constructive chemistry using the piezoelectric effect. Mechanical activation of piezoelectric nanoparticles generates several volts of electrochemical potential on the nanoscale. I present a method to harness this electro-mechanical reaction to enable polymerization reactions such as atom-transfer radical polymerization (ATRP) and copper-catalyzed azide-alkyne ‘click’ (CuAAC) using piezo reduction to generate a Cu(I) based catalysts. This research project is an entirely new area of polymer mechanochemistry and we were the first to demonstrate piezochemically-activated polymerization reactions. We are now starting to develop polymeric systems in which mechanical stress plays a constructive role.