REAL-SPACE MEASUREMENT OF STRUCTURE IN PHASE-SEPARATING BINARY-FLUID MIXTURES

In off-critical binary fluid mixtures undergoing phase separation, a p olydisperse set of minority phase domains grows in a matrix of the maj ority phase. With confocal microscopy and digital image processing, we have made direct three-dimensional measurements of structure in phase separated mixtures of low molecular weight polymers. The distribution of domain sizes and the spatial correlations in these mixtures exhibi t dynamic scaling, implying that the coarsening may be viewed entirely as an increase in length scale. This coarsening process appears to be driven by aggregation of domains.