Effect of upper contact line on sliding behavior of water droplet on superhydrophobic surface

• 来源期刊: 科学通报（英文版）
• 年，卷（期）: 2009,（5）
• 页码范围: 727-731
• 页数: 5页
• 语种: 英文
• DOI: 10.1007/s11434-009-0029-2

摘要

With a low surface energy, high apparent contact angle(150°) and low sliding angle(＜5°), superhy-drophobic surface has recently been attracting a great deal of attention. The true factor determining the sliding angle still remains unclear. In this paper, various superhydrophobic silicon surfaces with pillars are fabricated by photolithography and hydrophobized with octadecyltrichlorosilane (OTS). Relations between sliding angles and micro-structured surfaces are being investigated in detail with 10 mg water droplets in C-B state and mixed state. Experimental pictures and data show that the sliding angle is independent of pillar heights from 20 to 80 μm, increasing the space between pillars causes decrease in sliding angle, and increasing the side lengths of pillars causes increase in sliding angle. Moreover, the sliding angle is irrelevant to the state of interfacial contact area of water-solid and lower contact line. It is concluded that the sliding angle of water droplet on the micro-structured surface is merely deter-mined by the upper contact line.