Thermodynamic aspect of the shift of concave liquid-vapor interfacial phase equilibrium temperature and its effect on bubble formation

The thermodynamic analysis conducted here demonstrates that the capillary p ressure discontinuity at the concave liquid-vapor interface could promote i nterfacial evaporation. The phase equilibrium temperature of the concave li quid interface decreases with increasing surface tension and/or decreasing radius of curvature of the concave liquid-vapor interface. The shift of pha se equilibrium temperature and, hence, of latent heat implies that interfac ial evaporation may even occur at a temperature lower than the nominated sa turation temperature. According to these analytical results, bubbles can in itiate from active cavities as long as the temperature of the liquid microl ayer under the bubbles is higher than the phase equilibrium temperature, wh ich may even be lower than the nominated saturation temperature. The conclu sion is consistent with experimental observations about bubble formation. ( C) 2001 Elsevier Science Ltd. All rights reserved.