Conversion of Surface Energy and Experimental Investigation on the Self-motion Behaviors of Liquid Droplets on Gradient Surfaces

摘要：

A surface with surface energy gradient was fabricated by using a controlled photodegradation technique of a fluoroalkylsilane self-assembled monolayer (SAM) using irradiation of vacuum ultraviolet light (wavelength=172 nm). Visualization experiments were carried out to investigate the motion behaviors of water droplets on horizontal gradient surfaces. System free energy conversion was analyzed to understand the mechanics of the droplet self-motion. The results show that the liquid droplets were self-propelled to move from hydrophobic region to hydrophilic region on horizontal gradient surfaces. The motion process of the water droplet experienced an accelerating stage and a decelerating stage. The velocity of 2 μL water droplet reached to a maximum of 23.28 mm/s. In the droplet motion on the horizontal gradient surface, the deformation and spread of the droplet continuously release out the interfacial and gravitational potential energy, which offers the kinetic energy for the droplet motion. However, the released interfacial energy is three orders of magnitude larger than the released gravitational potential energy. Thus, the released interfacial energy is the main source of driven energy for the droplet motion. The theoretical analysis is consistent with the experimental results.

关键词： Surface energy gradient Energy conversion Self-driven Self-motion Self-assembled monolayer

作者: Changsong Liu Jigen Zhou Dongmei Zheng Yong Wan Zhiwen Li

作者单位: School of Mechanical Engineering, Qingdao Technological University, Qingdao, 266033, China

会议类型: 国际会议

会议名称: 11th IUMRS International Conference in Asia(第十一届国际材联亚洲材料大会 IUMRS-ICA 2010)

会议地点: 青岛

会议语种:英文

页码: 596-601

在线出版日期: 2010-09-25（万方平台首次上网日期，不代表论文的发表时间）