Video microscope and elastic light scattering studies of fast-mode kinetics in surface-mediated spinodal decomposition

Abstract

We present time-resolved video microscope and elastic light scattering studies of the domain-pattern selection and growth of spinodal decomposition in critical mixtures of guaiacol and glycerol-water constrained to a cell 0.5 mm thick. The structure functions show two peaks with different kinetics: a slow mode with L(t)\ensuremath{\sim}${\mathit{t}}^{1/3}$ and a ``fast mode'' with L(t)\ensuremath{\sim}${\mathit{t}}^{\mathit{b}}$, where b ranges from 1.0 to 1.5 depending on the quench depth (0.03 \ifmmode^\circ\else\textdegree\fi{}C\ensuremath{\le}\ensuremath{\Delta}T\ensuremath{\le}0.35 \ifmmode^\circ\else\textdegree\fi{}C). In this study we discuss our observations of the fast mode's growth. We have used both elastic light scattering and direct visualization via video microscopy and digital image processing to study the morphology and kinetics of these structures. Parameters such as the quench depth and the treatment of the cell's windows have been varied, with results suggesting that domain growth proceeds with a power law that is independent of which phase wets the surface.