The Relation between Contact Angle and Drop Size for Water at its Boiling Point for a Pressure Range 50–760 Torr

Abstract

Contact angles have been measured using water drops of specified sizes, and in equilibrium with their vapor only, at their boiling point when residing on a copper surface at pressures ranging from 50–760 Torr.No appreciable change of contact angle with drop diameter was evident for sizes of 0.5 cm or more, but below this value the angles were dependent on the drop diameter, the effect of reducing pressure being to increase the dependency. The phenomenon is qualitatively explained in terms of gravity and surface roughness influences.