Structure and dynamics of interface around a quenched impurity in a colloidal liquid film

RESUMO

The interfacial structure and dynamics around a quenched impurity is far from understood till date. Here we explore the structural and dynamical properties of interface between colloidal fluid film and a quenched impurity by using computer simulation. We tune the size($\sigma_{imp}$) of a quenched pinned impurity and observe that the impurity surface is wetted by a fluid layer, giving rise to a finite-width interfacial region for sufficiently large impurities. Beyond this interfacial region, the host fluid exhibits quasi-long ranged orientational order(QLRO) due to the fluid- crystal phase coexistence. We find that the mean diffusivity becomes very low in the QLRO phase where the self van Hove function shows an exponential tail, signature of dynamic heterogeneity within the system. In the presence of second impurity the orientational order is suppressed if the fluid layers around the impurity particles overlap.