Tuning mechanical properties of polymer-grafted nanoparticle networks by using biomimetic catch bonds

ORAL

Abstract

Cross-linked networks of polymer-grafted nanoparticles (PGNs) constitute a class of composites with tunable mechanical properties that exhibit a self-healing behavior. A PGN network consists of nanoparticles that are decorated with end-grafted polymer chains. Reactive groups on the free ends of these grafted chains can form bonds with the chain ends on the nearby particles. We study these materials using a 3D computational model that encompasses the particle-particle interactions, the kinetics of bond formation and rupture, and the external forces applied to the network. In our model, a fraction of cross-links is formed through biomimetic “catch” bonds. In contrast to conventional “slip” bonds, catch bonds can effectively become stronger under a deformation. We show that by varying the fraction of these catch bonds in the network, the toughness, ductility, and tensile strength of the material could be tuned to desired levels.

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Authors

  • Badel L. Mbanga

    Chemical Engineering Department, University of Pittsburgh, Pittsburgh, PA 15261, USA, Chemical Engineering Department, University of Pittsburgh, Pennsylvania 15261, USA

  • Balaji V. S. Iyer

    Chemical Engineering Department, University of Pittsburgh, Pennsylvania 15261, USA

  • Victor V. Yashin

    Chemical Engineering Department, University of Pittsburgh, Pennsylvania 15261, USA, Chemical Engineering Department, University of Pittsburgh, Pittsburgh, PA 15261, USA

  • Anna Balazs

    Univ of Pittsburgh, Department of Chemical Engineering, University of Pittsburgh, Chemical Engineering Department, University of Pittsburgh, Pennsylvania 15261, USA, Department of Chemical Engineering, The University of Pittsburgh, University of Pittsburgh, Chemical Engineering Department, University of Pittsburgh, Pittsburgh, PA 15261, USA