Effect of Wettability on Vacuum-Driven Bubble Nucleation

Nucleation is the formation of a new phase that has ability to irreversibly and spontaneously grow into large-sized nucleus within body metastable parent phase. In this experimental work, effect wettability on incipiation vacuum-driven bubble nucleation, boiling, consequent rate evaporative cooling are studied. One hydrophilic (untreated), three hydrophobic (chlorinated polydimethylsiloxane, chlorinated fluoroalkylmethylsiloxane (heptadecafluoro-1,1,2,2-tetrahydrodecyl)triethoxysilane) glass vials different wettabilities were filled with degassed deionized water exposed controlled vacuum inside transparent desiccator. The was increased by 34 mbar abs. (1 inHg rel.) steps 15-min waiting period observe nucleation. average onset pressures for gas/vapor nucleation in CM, CF, HT 911 ± 30, 34, 925 17 abs., respectively. Bubble not observed vial even at 65 pressure. During boiling temperatures hydrophilic, reduced from room temperature (~22.5 °C) 15.2 0.9, 13.1 12.9 0.5, 11.2 0.3 °C, results study show container surface strong influence vapor/gas cooling. These findings expected be useful develop wettability-based technologies.