GROWTH OF DODECYLAMMONIUM DODECYL-SULFATE CRYSTALS

Spontaneous formation of dodecylammonium dodecyl sulfate (DDADS) has been studied in batch precipitation experiments from solutions of high ionic strength and low surfactant concentrations. Formation of crystalline DDADS is found to be an instant process. Growth of DDADS crystals from equimolar reactant solutions is controlled by recrystallization and can be described by the following relation for the volume size median (dv with time (t): dv = 4.8 × 10-7 × t0.223. In nonequimolar systems other processes which occur parallel to the DDADS growth control overall precipitation kinetics and promote secondary phase formation. © 1992.