Kinetic Friction of Non-Coalescing and Non- Wetting Drops

This project has focused on the experimental determination of the frictional forces associated with noncoalescing and nonwetting systems. In particular, the focus has been on friction associated with an isothermal nonwetting droplet sliding on a solid surface. The nonwetting phenomenon is driven by the establishment of a thin (of order microns in thickness) layer of lubricating gas that is swept by viscous action into the space between the liquid and solid, preventing them from coming into contact. The mechanism has been described in the review article by Neitzel & Dell'Aversana (2002). The work performed under this NASA GSRP sponsorship extends work done by Dell'Aversana & Neitzel (2004) on the load-carrying capacities of thermocapillary nonwetting droplets for a given relative displacement of the two surfaces in question.