摘要
目的在振动的超疏水锯齿表面上,液滴表现出明显的运动特征,探究在该过程中液滴的运动机理及影响因素。方法采用铝片制作一系列具有一定倾角和高度的非对称锯齿状表面,使用疏水涂层Glaco Soft 99均匀喷涂,并干燥其表面,重复多次实验,直到表面具有稳定的超疏水性。加载一定的振动,对表面振动液滴的动态行为进行研究。结果在一定的振动范围内,当频率的作用范围为10~100Hz,振幅的作用范围为0~2 mm时,随着振动参数的增加,超疏水锯齿表面上的液滴会产生4种不同的行为,即静止、定向蠕动、跳跃、破裂等。实验表明,超疏水锯齿表面振动液滴的最快运动速度为8 cm/s。针对液滴的定向蠕动行为,运用力学分析方法,建立了液滴运动的物理模型,并分析了振动特征参数、锯齿表面参数、液滴体积对液滴运动特征的影响。结论对于一定尺寸的液滴,存在一个由共振频率和最优振幅组成的最佳的振动加速度,可使液滴达到该条件下的最优运动速度。同时,通过改变锯齿表面的结构参数,可使液滴运动速度更快,并且随着液滴体积的增加,液滴运动速度呈现先增快、后减慢的趋势。
Droplets show apparent dynamic properties on a superhydrophobic vibrating ratchet surface.The work aims to explore the motion mechanism and influencing factors of droplets in this process.In this paper,a physical model of droplet motion was developed and the effect of various parameters on dynamic behaviors of droplets was explored.In the experimental section,firstly,a series of asymmetric ratchet surfaces with a certain inclination and height were fabricated with aluminum sheets.Next,the ratchet surfaces were uniformly sprayed and dried with a hydrophobic coating,Glaco Soft 99,and the procedure was repeated several times until the surfaces had a stable superhydrophobicity.At this point,it was not necessary to consider the adhesion between the droplet and the ratchet surface.Finally,the ratchet surface was fixed to the shaking table,a drop of deionized water was placed on the surface,a certain amount of vibration was loaded,and the droplet motion was captured at a rate of 1000 fps with a high-speed camera(Fastec Imaging Hispec 3).The dynamic behavior of the vibrating droplet was observed and studied.It was found that within a certain vibration range,in which the frequency action range was 10-100 Hz and the amplitude action range was 0-2 mm,the vibrating droplet on the superhydrophobic ratchet surface exhibited four different behaviors,i.e.,stationary,directional creep,jumping,and rupture behaviors,as the vibration amplitude increased.The experimental results showed that the fastest motion of the vibrating droplet on the superhydrophobic ratchet surface can reach 8 cm/s,which was much faster than the results of similar studies.Considering the continuity of droplet motion,this work investigated the directional creeping behavior of the droplet.During the motion of the droplet,experimental pictures were taken every 10 ms,and the contact angle at both ends of each picture and the center of mass of the droplet were measured.A physical model of droplet motion was proposed by considering the driving force and resistance
作者
黄宝罗
贾志海
康学良
潘桂暖
HUANG Bao-luo;JIA Zhi-hai;KANG Xue-liang;PAN Gui-nuan(University of Shanghai for Science and Technology,Shanghai 200093,China)
出处
《表面技术》
EI
CAS
CSCD
北大核心
2023年第1期278-284,共7页
Surface Technology
基金
国家自然科学基金(51776128)。
关键词
液滴
超疏水
锯齿表面
振动
定向驱动
droplets
superhydrophobic
ratchet surfaces
vibration
directional drive
