Thin-film flows of granular suspensions on a solid surface

This review article examines the complex dynamics of thin-film flows of granular suspensions spreading over rigid solid substrates with free air interfaces. Such systems feature an involved coupling of the free-surface dynamics with the flow and microstructure of the suspension. In particular, we develop two canonical thin-film situations: drop spreading and dip-coating. In drop spreading, confinement of the particulate phase near the advancing contact line alters both the spreading rate and the interface shape. In dip-coating, understanding the entrainment of fluid and particles becomes challenging as the film thickness approaches the particle size.