Floating of heavy objects on liquid surfaces coated with colloidal particles

Floating of heavy objects supported by water coated with colloidal hydrophobic powders was studied. Critical weight of rectangle plate (micro-boat) supported by water coated by lycopodium, polyethylene, polyvinylidene fluoride, polytetrafluoroethylene, and silicon dioxide was established. All water surfaces coated with colloidal particles demonstrated larger supporting ability of floating than clear water. This observation may be related to air trapping occurring when the object contacts with a liquid surface coated by colloidal particles and also to the strengthened pinning of the triple line in this situation. We observed essential strengthening of pinning effects, when floating rectangular plate was supported by water coated with hydrophobic particles, resulting in the enhanced supporting ability of floating.