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.