The diffusion of Brownian particles in a gravitational field and their adhesion to a horizontal plane is analyzed, from the point of view of both the Langevin and Smolukowski equations. It is shown that even when hydrodynamic interactions of the diffusing particles with the collector and the preadsorbed particles are taken into account, the structure built up by the irreversibly fixed particles and the jamming coverage are uniquely determined by one parameter $R^{*}$. This latter depends solely on the radius of the particles, their density relative to the density of the fluid, the temperature, and the acceleration of gravity. The viscosity of the fluid does not enter into this parameter.

• Received 2 August 1996

DOI:https://doi.org/10.1103/PhysRevE.54.6962