Aggregation of urea in water: Dynamic light scattering analyses

The aggregation behavior of urea in water is multifaceted; the urea-urea, urea-water, and water-water interactions lead to noteworthy characteristics with changes in condition. The concentration- and temperature-dependent aggregation of urea was studied using dynamic light scattering (DLS). The particle size analysis and polydispersity between 1.0 and 12.0 M aqueous urea revealed pronounced aggregation trends beginning at or above 6.0 M. A reversal of the observed trend in intensity correlation function was noticed above 10.0 M. Temperature-dependent intensity correlation functions between 20 and 70 °C corroborated the finding. An anomalous behavior at 60 °C was observed, supported by the polydispersity of the systems, throughout all concentrations of urea studied.