Elodie Bourgeat-Lami

Investigation of particle nucleation in surfactant‐free emulsion polymerization of styrene using Laponite clay as Pickering stabilizer is considered. The effective number of clay platelets contributing to the surface charge of the polymer particles is calculated, and used to estimate their stabilizing efficiency. A coagulative nucleation mechanism is proposed and the coagulation coefficient is calculated using the Derjaguin–Landau–Verwey–Overbeek theory. The Hamaker constant involved in the attractive potential of the clay‐polymer composite particles is measured experimentally. The model is found to fit the experimental data in terms of the number of nucleated particles and the nucleation period. The effective number of clay platelets contributing to the surface charge is found higher than the number of platelets allowing full polymer latex surface coverage at the end of nucleation. Moreover, efficient stabilization against coagulation requires almost complete coverage.