DYNAMIC CONTACT ANGLES AND HYDRODYNAMICS NEAR A MOVING CONTACT LINE

The contact angle is an important boundary condition needed to predict the shape of menisci. However, its measurement and use under dynamic conditions are not well understood. We have measured the shape of meni sci very close to moving contact lines over a suite of geometric shape s for the macroscopic menisci. The excellent agreement between theory and experiment establishes that the proposed boundary condition charac terizes only the materials of the system. Implications for the microsc opic physics controlling the dynamic contact angle are explored.