Self-propelled and size distribution of condensate droplets on superhydrophobic surfaces

被引：0

作者：

Zhou, Bao-Yu ^{[1
,2
]}

Yang, Hui ^{[1
]}

Feng, Wei ^{[1
]}

Jiang, Yu-Feng ^{[1
]}

Chen, Yue ^{[1
]}

机构：

[1] Hubei Polytechnic University, Huangshi,435003, China

[2] Yunnan University, Kunming,650091, China

来源：

Surface Technology | 2020年 / 49卷 / 05期

基金：

中国国家自然科学基金;

关键词：

Adhesives - Condensation - Copper compounds - Drops - Electrochemical deposition - Electrolytes - Heat transfer - Hydrophilicity - Hydrophobicity - MATLAB - Morphology - Reduction - Surface morphology - Surface properties - Wetting;

D O I：

10.16490/j.cnki.issn.1001-3660.2020.05.020

中图分类号：

学科分类号：

摘要：

The work aim to optimize the experimental parameters of preparing copper hydroxide nanostructures by electrochemical deposition and to explore the size distribution of condensate droplets on different wettability surfaces. Orthogonal test method was adopted to comprehensively consider the influence of electrolyte concentration, reaction temperature, polarization time and current density on contact angle, and its surface morphology was analyzed by SEM. At the same time, a method to quickly and accurately identify, extract and count the characteristic value of condensate droplets was proposed based on MATLAB programming software. The optimal parameters of the orthogonal test were concentration 0.5 mol/L, temperature 5 ℃, time 2000 s, current density 4 mA/cm2. Under this condition, the contact angle of the sample was up to 168.8° and the sliding angle was less than 3°. The condensation test results shown that on the superhydrophobic surface, condensate droplets can coalescence and self-propelled frequently. The average diameter of droplets was the smallest, and the proportion of droplets in the range of 1~10 µm remained at about 50%. On the hydrophobic and hydrophilic surfaces, condensation droplets can only merge, and the average diameter of droplets increased significantly. And the condensate droplet density on the superhydrophobic, hydrophobic and hydrophilic surfaces was stable at about 2000 mm2, 1000 mm2 and 360 mm2 respectively, finally. We found that the nano-needle structure can minimize the solid-liquid contact area, reduce the adhesive force of condensate droplets, improve the condensate self-propelled frequency, reduce the diameter of condensate droplets, and improve the update frequency of condensate droplet, which is expected to achieve efficient condensation heat transfer. At the same time, the feasibility of the image processing method for the size distribution of condensing droplets is verified by comparison with the image-J processing results. © 2020, Chongqing Wujiu Periodicals Press. All rights reserved.

引用

页码：170 / 176