Temperature Pinning of a Sessile Bubble

Abstract

A relatively new term of colloid science, “pinning,” characterizes the phenomenon when a drop or bubble, spreading over a solid surface, suddenly stops its movement at its base. Usually pinning is observed with an increase in the drop or bubble volume by pumping substances into them. In this paper, small but macroscopic air bubbles were studied at the water–silicon interface, and their volume increased in a non-contact way by increasing temperature. The observed phenomenon can be called temperature pinning. The experiments were carried out both on the natural hydrophilic surface of silicon wafers and on their surfaces artificially hydrophobized to various degrees in the temperature range of 20–75°C. In all cases, temperature pinning was observed in the initial temperature range from 20°C, but was also observed at other temperatures. The general conclusion is that temperature pinning is common and has various manifestations.