Negative Pressure in Water Capillary Bridges at Nanocontacts
Seung H. Yang, Michael Nosonovsky, Huan Zhang, Koo-Hyun Chung
Negative Laplace pressure may develop inside a water capillary bridge formed between two bodies and contribute to the force required to pull them apart. Because of the negative pressure, nanoscale water capillary bridges may not be stable. We show that pressure inside a nanoscale water capillary bridge may reach absolute negative value (corresponding to tensile stress). The negative pressure is within the spinodal limit for water suggesting that the water bridge may be in the metastable state. In addition, the size of a nanoscale water capillary bridge is smaller than the critical size for cavitation, indicating that cavitation bubbling is unlikely for nanocontacts..