2D Coarsening in phase-separated polymer solutions: Dependence on distance from criticality

Polymer solutions of various compositions have been phase separated in two dimensions in order to monitor the growth rate of the domain size d associated with coarsening in restricted dimensions. For off-critical solutions, d grows approximately as t1/3, consistent with theory. For near-critical solutions, d grows approximately as t1/3 at early times, followed by a crossover to a rate that is consistent with the t2/3 growth rate reported in some numerical studies. The early-time coarsening of critical solutions is dominated by critical wetting and a highly bimodal size distribution, making measurements of d difficult to obtain.