Temperature Dependence of Sessile Bubble Contact Angle at a Water–Silicon Interface

Abstract

The goal of this work is the experimental verification of a recently formulated thermodynamic theory of the temperature dependence of sessile bubble contact angle [Rusanov, A.I., Colloid J., 2020, vol. 82, p. 303]. In particular, the possibilities of an increase in small contact angles and a decrease in large ones (larger than 90°) are tested. The experiments are carried out with a bubble at a water–silicon interface using two types of polished silicon plates: clean plates with a water contact angle of 12° and plates with a hydrophobized surface and the water contact angle of 104° within a temperature range 20–80°C. In both cases, the experiments have confirmed the theory. In addition, a temperature pinning effect (anchoring of the three-phase contact line) has been revealed for the sessile bubble.