An Experimental Apparatus for the Measurement of Sessile Drop Contact Angles at Elevated Temperatures

摘要

An equipment suitable for the measurement of the contact angles of molten sessile drops on solid substrate was developed. Temperatures up to 2250F may be readily controlled to within plus or minus 10F for long periods of time. The environment of the specimens may be either vacuum (to 0.00001 Torr) or a specific gas. Photographic techniques were used to record the contact angles. Experimental results of molten Na2B4O7 on metal substrates showed a standard deviation of less than 2 deg. The uncertainly introduced by the angle measurement process was shown not to exceed +2 or -2 deg. (Author)