摘要
The dynamic process of the evaporation and the desiccation of sessile saline colloidal droplets,and their final deposition are investigated.During the evaporation,the movement of the colloidal particles shows a strong dependence on the salt concentration and the droplet shape.The final deposition pattern indicates a weakened coffee-ring effect in this mixed droplet system.The microscopic observation reveals that as evaporation proceeds,the particle motion trail is affected by the salt concentration of the droplet boundary.The Marangoni flow,which is induced by surface tension gradient originating from the local evaporative peripheral salt enrichment,suppresses the compensation flow towards the contact line of the droplet.The inhomogeneous density and concentration field induced by evaporation or crystallization can be the major reason for various micro-flows.At last stage,the distribution and crystallization of Na Cl are affected by the colloidal particles during the drying of the residual liquid film.
The dynamic process of the evaporation and the desiccation of sessile saline colloidal droplets, and their final deposition are investigated. During the evaporation, the movement of the colloidal particles shows a strong dependence on the salt concentration and the droplet shape. The final deposition pattern indicates a weakened coffee-ring effect in this mixed droplet system. The microscopic observation reveals that as evaporation proceeds, the particle motion trail is affected by the salt concentration of the droplet boundary. The Marangoni flow, which is induced by surface tension gradient originating from the local evaporative peripheral salt enrichment, suppresses the compensation flow towards the contact line of the droplet. The inhomogeneous density and concentration field induced by evaporation or crystallization can be the major reason for various micro-flows. At last stage, the distribution and crystallization of Na Cl are affected by the colloidal particles during the drying of the residual liquid film.
作者
孙弘辉
李伟斌
纪文杰
戴国亮
郇勇
王育人
蓝鼎
Hong-Hui Sun;Wei-Bin Li;Wen-Jie Ji;Guo-Liang Dai;Yong Huan;Yu-Ren Wang;Ding Lan(National Microgravity Laboratory,Institute of Mechanics,Chinese Academy of Sciences,Beijing 100190,China;State Key Laboratory of Nonlinear MechanicsLNM,Institute of Mechanics,Chinese Academy of Sciences,Beijing 100190,China;School of Engineering Sciences,University of Chinese Academy of Sciences,Beijing 100049 China)
基金
Project supported by the National Natural Science Foundation of China(Grant Nos.11472275 and U1738118)
the Chinese Academy of Sciences Key Technology Talent Program
the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB22040301)
