Lubrication model for vapor absorption into hygroscopic liquid desiccant droplets

摘要

The liquid desiccant is a special type of hygroscopic aqueous salt solution, which has been applied in various dehumidification, absorption, and desalination systems. In contact with humid air, the liquid desiccant droplet grows due to vapor absorption, and the droplet motion differs depending on the surface wettability. Previous experimental results from our group show that on hydrophilic substrates, the desiccant droplet gradually spreads with a timescale of 10~3 s as vapor absorption proceeds. The slow spreading phenomenon is intriguing as it differs from the rapid droplet spreading described by the classical Tanner's law when a droplet gets initial contact with the solid surface.