Atomic Scale Interfacial Transport at an Extended Evaporating Meniscus

Abstract: Recent developments in fabrication techniques enabled the production of nano- and angstrom-scale conduits. While scientists are able to conduct experimental studies to demonstrate extreme evaporation rates from these capillaries, theoretical modeling of evaporation from a few nanometers or sub-nanometer meniscus interfaces, where adsorbed film, transition film and intrinsic region are intertwined, is absent in the literature. Using the computational setup constructed to identify the detailed profile of a nano-scale evaporating interface, we discovered the existence of lateral momentum transport within and associated net evaporation from adsorbed liquid layers, which are long believed to be at the equilibrium established between equal rates of evaporation and condensation. Contribution of evaporation from the adsorbed layer increases the effective evaporation area, reducing the excessively estimated evaporation flux values. This work takes the first step towards a comprehensive understanding of atomic/molecular scale interfacial transport at extended evaporating menisci. The modeling strategy used in this study opens an opportunity for computational experimentation of steady-state evaporation and condensation at liquid/vapor interfaces located in capillary nano-conduits.