Light scattering studies of the sol-to-gel transition in particulate systems.
We present investigations of the kinetics of the colloidal sol-to-gel transition by combining small angle static light scattering (SASLS) and dynamic light scattering (DLS) techniques. Dilute monomer volume fractions were used to allow for a full investigation of the gelation to obtain all possible kinetic regimes. Our data verify the predictions of a kinetic theory, the ideal gel point (IGP) theory, where three regimes of kinetics are expected. We observe the first regime, the well-known cluster-dilute regime, with a kinetic exponent of z = 1. Followed by a cluster-dense regime with an enhanced kinetics and z ≃ 2. Finally, a gelation regime is observed where the aggregate growth slows and ceases to grow at the IGP predicted size, Rg,G. These results quantitatively verify the IGP theory. We conclude that kinetic description provides a complete theory of the gelation process from sol to gel.