Evaporation of a nanodroplet on a rough substrate

• Published in: Frontiers of physics 2017-10, Vol.12 (5), p.191-197, Article 126401
• Main Authors: 孙永娟, 黄韬, 赵俊锋, 陈勇
• Format: Article
• Language: English
• Subjects: Astronomy; Astrophysics and Cosmology; Atomic; Condensed Matter Physics; Contact angle; Droplets; Evaporation; Hydrophobicity; Molecular; Molecular dynamics; nanodroplet; Optical and Plasma Physics; Particle and Nuclear Physics; Physics; Physics and Astronomy; Research Article; Roughness; Self-assembly; Simulation; Substrates; Wettability; 动力学模拟; 基底; 接触线; 液滴蒸发; 粗糙度; 纳米尺度; 蒸发技术; 蒸发过程
• ISSN: 2095-0462; 2095-0470
• DOI: 10.1007/s11467-016-0631-0

The wettability and roughness of a substrate are crucial to the evolution of the contact angle and three-phase contact line in the evaporation of sessile droplets. In this paper, by performing molecular dynamics simulations for droplet evaporation at the nanoscale, we show that the wettability is more important than the roughness. For a smooth substrate, the evaporation behavior of a nanodroplet is similar to that at the macroscopic scale. This similarity is also observed in the case of a rough hydrophilic substrate. However, for a rough hydrophobic substrate, both the constant contact angle and contact line pinning appear in turn during evaporation. This suggests that the roughness of the hydrophobic substrate is useful for the evaporation technique in self-assembly at the nanoscale.