On the identification of bridging flocculation: An extended collision efficiency model

Abstract

A new generalized collision efficiency model for bridging flocculation was developed. It comprises the La Mer, the Moudgil and the Molski models. The extended model allows to separate and quantify the contributions of the different aggregation mechanisms (slow coagulation, weak flocculation and bridging flocculation). The model was tested for polystyrene particles covered with different amounts of bovine serum albumin (BSA). Single-cluster light scattering was employed to study the aggregation kinetics and to obtain the initial aggregation rate constant. It was found that the simple La Mer model cannot explain the experimental results whilst the Molski model gives reasonably good results for fast but fails for slow aggregation processes. Only the extended model works for slow and fast aggregation processes.