Dynamic light scattering with an original optical scheme has been used for the investigation of opaque (strongly light-absorbing) asphaltene colloids in crude oils and hydrocarbon mixtures. Diffusion-limited aggregation and reaction-limited aggregation as well as a crossover between these two regimes have been observed. A simple interpolation for the crossover kinetics is proposed. Asphaltene colloidal structures, originally persisting in crude oils, have been detected. Addition of a precipitant above a threshold induces asphaltene aggregation. Depending on the nature of the precipitant, different crude oils respond differently on its addition: (a) exponential-in-time growth of aggregates to huge flocks or (b) fast formation of stable-in-size particles.
© 2001 Optical Society of America
Yevgeniy G. Burya, Igor K. Yudin, Victor A. Dechabo, Victor I. Kosov, and Mikhail A. Anisimov, "Light-Scattering Study of Petroleum Asphaltene Aggregation," Appl. Opt. 40, 4028-4035 (2001)