| This thesis reports studies of polymer powder and latex coatings and their applications. The main objective is to reveal the successive or interacting mechanisms of the film formation process by which continuous coatings, layers, or films, evolve from particulate suspensions. The approach is to record, by microscopy, the evolution continuously, or else to interrupt the process sequentially and image each stage. The results are interpreted in terms of forces and interdiffusion that produce partially continuous, porous coatings and fully continuous ones devoid of porosity. Forces arise from electrostatic interaction, surface tension, van der Waals and other short-ranged forces, and shrinkage stresses; diffusion is driven by chemical potential gradients from composition and configuration gradients. |
