纳米结构表面浸润性质的分子动力学研究

Wettability of Surface with Nano-structures Studied by Using Molecular Dynamics Simulation

采用分子动力学方法研究了氩纳米液滴在铂金属及其模型固体表面的浸润现象 ,获得了液滴在平滑表面和三角纳米结构阵列表面的接触角和展布特性 .研究表明 ,液滴与壁面的势能作用较强时 ,液滴与纳米结构表面为均匀浸润 ,但是由于迟滞效应 ,接触角受表面纳米结构的影响不明显 ;势能作用较弱时 ,纳米结构间隙中存在类似蒸汽的低密度相 ,液滴与纳米结构表面为非均匀浸润 ,接触角受纳米结构的影响而增大 ;表面纳米结构可以使表面具有超疏水性 .

The molecular dynamics simulation method was applied to investigate the wettability of argon nano-droplets on platinum and other model solids. The contact angle and spreading characteristics of flat and triangle-array nano-structure surfaces were obtained. For the hydrophilic fluid-solid interaction, the homogeneous wetting took place between the droplet and the nano-structure surface, while the apparent contact angle was little affected due to the hysteresis. For the hydrophobic interaction, vapor-like phase appeared inside the nano-structure diastemata, and the wetting between the droplet and the nano-structure surface turned to be heterogeneous. Within the simulation scales, the contact angle increased with increasing the nano-structure size, and might even show surperhydrophobicity.