摘要
以聚二甲基硅氧烷(PDMS)材料为基底,采用光刻技术制备了微方柱状疏水表面,研究了垂直振动作用下,液滴在疏水表面的Wenzel-Cassie状态转变特性.研究表明,在某一振动频率下,随着振幅逐渐增大,不同体积液滴均能实现Wenzel-Cassie状态转变;当施加的振动频率接近某一体积液滴固有频率时,由于该液滴与振动平面发生共振,液滴发生浸润状态转变所需能量最小;该频率下其他体积液滴虽也可以实现浸润状态转变,但由于所施加振动频率偏离其固有频率,液滴发生浸润转变所需能量并非最小;振动频率偏离其固有频率越远,所需能量越大.结合表面物理化学和振动力学对该现象进行了理论分析.
The square-shaped pillars rough surface was prepared with the polydimethylsiloxane（PDMS） material by using the photolithographic techniques. The Wenzel-Cassie wetting transition of different size of droplets, gently placed on the surface, had been observed under the vertical vibration at different amplitudes achieved by adjusting, at a given frequency, the amplitude of the vertical displacement. When the forced vibration frequency is in accordance with the nature frequency of the droplet, that is to say, at the resonance frequency, the forced amplitude for Wenzel-Cassie wetting transition arrives to the lowest value. Although the Wenzel-Cassie wetting transition of other droplets were observed at this frequency, the energy for wetting transition is not the minimum as the imposed vibration frequency deviates from their natural frequencies. The farther the deviation between the vibration frequency and the natural frequency is, the more energy it requires. Meanwhile, the phenomenon is analyzed theoretically with the surface physical chemistry and mechanics of vibration.
出处
《科学通报》
EI
CAS
CSCD
北大核心
2014年第27期2663-2667,共5页
Chinese Science Bulletin
基金
国家自然科学基金(51176123)
上海市自然科学基金(11ZR1424800)
教育部高等学校博士学科点专项科研基金(20103120120006)资助
关键词
浸润转变
振动
液滴
共振
疏水表面
wetting transition
vibration
droplet
resonance
hydrophobic surface
