氯化钠和氯化钙结晶毛细管蒸发

o reveal the underlying mechanism of evaporation crystallization of salt in porous media,the evaporation crystallization processes of sodium chloride and calcium chloride solutions was investigated, respectively using microfluidic visualization experimental methods within both single- and multi-channel porous structures. It was found that the form of the nucleation in sodium chloride solution includes both porous and non-porous crystals, and the angular liquid membrane plays the role of salt transport to enhance the evaporation. Compared to sodium chloride solution, calcium chloride solution exhibits a slower evaporation rate. The solution will not evaporate completely at room temperature, and eventually exists in the form of crystalline hydrate, the evaporation gas-liquid interface will be blocked by crystals, which leads to the stop of the evaporation. Moreover, a large number of bubbles can be observed inside the solution in the drying process.