Activity-Triggered Rheological Strengthening and Toughening of Nanoparticle-Doped Supramolecular Gels

To achieve high mechanical strength in combination with large toughness is among the most challenging tasks for the design of functional supramolecular materials that persist in strong and rapid deformation. Based on recent progress in nanotechnology, including the design of synthetic self-propelling nanoparticles (NPs) and increasingly available experimental methods to synthesize noncovalently bonded supramolecular chains (NBSCs), we present a simulation model of a supramolecular gel doped with passive and active NPs. We then demonstrate how an activity-induced decoupling of the NP diffusion from the chain relaxation facilitates a modification of the linear and nonlinear rheological properties of gels made of NBSCs. We analyze the static and dynamical behaviors of these NBSCs and perform a Rouse mode analysis to determine the relaxation spectra and to quantify the stress relaxation moduli and demonstrate that activated NPs induce a structural relaxation of cross-linked and entangled NBSCs. The rheological improvements triggered by such dynamic tuning offer interesting pathways for a further expansion of the practical applications of supramolecular materials in emerging fields, ranging from the aerospace and automobile industries to the design of safe and energy-efficient solid-state batteries.