Droplet growth and coarsening during heterogeneous vapor condensation

A theoretical description of droplet growth and coarsening is presented for vapor condensing onto a partially wetting surface. Both individual droplet growth and coalescences are included in the description. The coupling of these growth mechanisms results in two characteristic lengths. The radii of individual droplets, nucleated onto the surface, increase as a power of time: R∼$t^m$. Diffusion-limited growth on the surface leads to a characteristic exponent m=(1/4. As a result of coalescences, however, the average droplet radius grows with an exponent of 3m. Further predictions of the theory are also discussed.