title: Mechanophore activation at heterointerfaces.
abstract: Silica nanoparticles grafted with poly(methyl acrylate) (PMA) chains anchored by a maleimide-anthracene cycloadduct were synthesized to demonstrate mechanochemically selective activation of mechanophores at heterogeneous interfaces. By quantifying the anthracene-containing cleaved PMA polymers, which are generated via retro-[4 + 2] cycloaddition reactions, the first-order kinetic coefficient was determined. Activation characteristics of mechanophores anchored to a nanoparticle exhibit behavior similar to mechanophore-linked polymers, e.g., threshold molecular weight and linear increase in rate coefficient with molecular weight above the threshold. This model system is thus valuable as a probe to test stress activation of interfacially bonded mechanophores relevant to the design of fiber-reinforced polymer composites.
authors.affiliation: Beckman Institute for Advanced Science and Technology, Department of Materials Science and Engineering, Department of Chemistry, University of Illinois at Urbana-Champaign , Urbana, Illinois 61801, United States.
authors.forename: Jun
authors.initials: J
authors.lastname: Li
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Shiraki
authors.forename: Bin
authors.initials: B
authors.lastname: Hu
authors.forename: Roger A E
authors.initials: RA
authors.lastname: Wright
authors.forename: Bin
authors.initials: B
authors.lastname: Zhao
authors.forename: Jeffrey S
authors.initials: JS
authors.lastname: Moore