微液滴在超疏水表面的受迫振动及其接触线的固着-移动转变  

Stick-slip transition of a water droplet vibrated on a superhydrophobic surface

作　　者：周建臣 耿兴国[1] 林可君 张永建[2] 臧渡洋[1] 

机构地区：[1]功能软物质与材料课题组,空间应用物理与化学教育部重点实验室,西北工业大学理学院,西安710129 [2]凝固技术国家重点实验室,西北工业大学材料学院,西安710072

出　　处：《物理学报》2014年第21期312-317,共6页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:51301139);教育部博士点新教师基金(批准号:20126102120058);陕西省自然科学基金(批准号:2012JQ1016);西北工业大学基础研究基金(批准号:JCY20130147)资助的课题~~

摘　　要：利用高速摄影技术对超疏水表面液滴振动的动态行为进行观测,研究液滴在不同频率下的振动特性.实验发现,液滴的共振频率满足Rayleigh方程,微液滴在超疏水表面具有自由液滴的振动性质.在80—200 Hz的驱动频率范围内,接触线出现了明显的固着-移动现象,液滴的振动频率是驱动频率的一半,液滴振动时的形变较大.当驱动频率大于200 Hz时,接触线基本固着,液滴的振动频率近似等于驱动频率,液滴共振时的形态边缘始终有节点存在.分析表明。We have studied the vibration behavior of a water droplet vibrated on a superhydrophobic surface via a highspeed camera. The resonance frequencies of the droplet satisfy the Rayleigh equation, suggesting that the droplet on a superhydrophobic surface can be regarded as a free droplet. Its real oscillation frequency is half of the driving frequency when it is vibrated at low frequencies（ 〈200 Hz）. It shows large shape deformation from a compressed puddle to a stretched spheroid. The three-phase contact line exhibits a stick-slip behavior. However, when the droplet is vibrated at frequencies greater than 200 Hz, the three-phase contact line is pinned to the substrate and the droplet is vibrated at the same frequencies as the external driving frequencies. It is found that the oscillation of the contact line and the large shape deformation of the droplet are responsible for the distinct behavior at low frequency.

关 键 词：超疏水表面 受迫振动 共振 接触线 

分 类 号：O647.1[理学—物理化学]