Effects of surface roughness and wettability on bubble nucleation of water containing insoluble gas: A molecular dynamics study

As heat dissipation in micro- and nanoelectronic devices has become a critical bottleneck limiting performance improvement, microscale boiling has attracted increasing attention in recent years. Bubble nucleation in water containing nitrogen as an insoluble gas on copper surfaces with varying roughness and wettability is systematically investigated using molecular dynamics (MD) simulations. The results show that increasing surface roughness significantly enhances bubble nucleation by providing additional nucleation sites. The characteristic time of bubble nucleation in water containing insoluble gas decreases with reduced surface hydrophilicity, which differs markedly from previous MD studies of boiling in pure water. This finding suggests that enhanced adsorption of insoluble gas on hydrophobic surfaces facilitates bubble nucleation, in good agreement with experimental observations. These results provide valuable theoretical insights into microscale boiling heat transfer and offer guidance for optimizing thermal management in micro- and nanoelectronic systems.