Kinetic crossover of rough surface growth in a colloidal system

Abstract

The scaling behavior of the surface of polystyrene colloidal particles depositing on the contact line between the colloidal latex film and the glass substrate is studied. We analyzed the morphology of the formed surface and the scaling exponents \ensuremath{\alpha} and \ensuremath{\beta}, defining the surface width w(L,t)\ensuremath{\sim}${\mathit{L}}^{\mathrm{\ensuremath{\alpha}}}$f(t/${\mathit{L}}^{\mathrm{\ensuremath{\alpha}}/\mathrm{\ensuremath{\beta}}}$). The value of roughness exponent \ensuremath{\alpha} changes from 0.5 in a time regime to 0.71 at later times of the depositing process. To our knowledge, this is the first experimental evidence of a crossover phenomenon of rough surface growth in a colloidal system. The underlying physical reason for this phenomenon is suggested. \textcopyright{} 1996 The American Physical Society.