Entropy-mediated mechanical response of the interfacial nanoparticle patterning.

The precise organization of nano-objects into well-defined patterns at interfaces is an outstanding challenge in the field of nanocomposites toward technologically important materials and devices. Herein, by means of computer simulations we show novel mechanomutable nanocomposites designed by binary mixtures of tethered Janus nanoparticles at the interface of a binary fluid mixture under mechanical pressure. Our simulations demonstrate that the nanoparticle organization in the systems undergo reversible transition between random state and long-ranged intercalation state, controlled by various structural parameters of the tethered chains and the applied pressure. The dynamical mechanism during the transition is explored through examining the diffusion trajectories of the nanoparticles confined at the interfaces. We provide a theoretical analysis of the lateral pressure induced by the tethered chains, which is fully supported by simulation data and reveals that the compression-induced transition is fundamentally attributed to the entropic effect from the tethered chains. Our study leads to a class of interface-reactive nanomaterials in which the transfer and recovery of interfacial nanopatterning presents precise and tunable mechanical responses.