Song Fenhong, Ma Long, Fan Jing, Chen Qicheng, Zhang Lihui, Li Ben Q
School of Energy and Power Engineering, Northeast Electric Power University, Jilin 132012, China.
Key Laboratory of Special Purpose Equipment and Advanced Processing Technology, Ministry of Education, Zhejiang University of Technology, Hangzhou 310014, China.
Nanomaterials (Basel). 2018 May 17;8(5):340. doi: 10.3390/nano8050340.
Molecular dynamic simulations were adopted to study the wetting properties of nanoscale droplets on rough silicon solid substrate subject to perpendicular electric fields. The effect of roughness factor and electric field strength on the static and dynamic wetting behaviors of a nano-droplet on a solid surface was investigated at the molecular level. Results show that the static contact angle tends to decrease slightly and show small difference with the increase of roughness factor, while it shows an obvious increase for the ramp-shaped surface because the appearing bottom space reduces the wettability of solid surface. Additionally, under the electric field, a nano-droplet was elongated in the field direction and the equilibrium contact angle increases with the increase of electric field strength. The nano-droplet was completely stretched to be column-shaped at a threshold value of the field. Besides, accompanied by the shape variation of water droplets, the molecular dipole orientations of water molecules experience a remarkable change from a random disordered distribution to an ordered profile because of the realignment of water molecules induced by electric fields.
采用分子动力学模拟研究了垂直电场作用下纳米级液滴在粗糙硅固体基底上的润湿特性。在分子水平上研究了粗糙度因子和电场强度对纳米液滴在固体表面静态和动态润湿行为的影响。结果表明，随着粗糙度因子的增加，静态接触角略有减小且差异较小，而对于斜坡形表面，静态接触角明显增大，这是因为出现的底部空间降低了固体表面的润湿性。此外，在电场作用下，纳米液滴沿电场方向拉长，平衡接触角随电场强度的增加而增大。在电场的阈值下，纳米液滴完全拉伸成柱状。此外，伴随着水滴形状的变化，由于电场引起的水分子重新排列，水分子的分子偶极取向经历了从随机无序分布到有序分布的显著变化。
