Discontinuous behavior of Rayleigh relaxation in supersaturated aqueous NH4H2PO4 solution

Abstract

The algorithm of Rayleigh intensity correlation is employed for the elucidation of relaxation time constants of the aqueous NH4H2PO4 solution with various concentrations. The result shows that there is a discontinuous (abrupt) increases in the relaxation time constant as the super-saturation state is reached. This quantity, the relaxation time constant, therefore, can be an order parameter. Also discussed is the dependence of the relaxation time constant on the aggregation number n in (H2PO4−)n. This dependence is complicated and may be crucial in understanding the aggregation process in the supersaturation state.