A microscopic mechanism for shock-wave generation in pulsed-laser-heated colloidal suspensions

Abstract

The kinetics of the heat and mass transport involved in vapor bubble formation around a colloidal particle which has been heated rapidly to high temperatures are examined with a theoretical model. It is argued that the likely mechanism of bubble formation on the nanosecond time scale is a spinodal decomposition of the liquid at the particle surface to the low density (vapor) phase. This process is shown to give rise to extremely rapid changes in the density and pressure fields of the fluid. The existence of such rapid events has been invoked to explain experimental observations of acoustic shocks generated in laser-pulse-heated colloidal suspensions.