Adiabatic spinodal decomposition in critical binary fluids

We discuss early-stage spinodal decomposition in a near-critical binary fluid for a situation in which the system is quenched abruptly by changing the pressure and in which the subsequent phase separation occurs adiabatically. The resulting nonequilibrium situation has features that do not fit conventional theoretical assumptions. We find that changes in the effective temperature during the transition can account for the lack of agreement between earlier theories and recent experimental results of Bailey and Cannell.