Zhang Yaxin, Jia Zhihai, Ning Yuxuan, Hou Wenxuan, Lyu Zhihao
School of Energy and Power Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China.
Langmuir. 2025 Jun 24;41(24):15583-15600. doi: 10.1021/acs.langmuir.5c01756. Epub 2025 Jun 12.
In industrial applications such as condensation heat transfer, frost suppression, and fog collection, the droplet in the Wenzel state exhibits a strong adhesion to the surface, hindering its migration. To prevent the wetting transition and improve droplet migration, a novel method by combining wettability gradients, liquid infusion, and mechanical vibration is proposed in this paper. A curved microgrooved surface with gradient wettability is fabricated via photolithography on a silicon wafer, and then, silicone oil is infused to form the liquid-infused surface. Subsequently, a vertical vibration is applied to induce droplet deformation, enhancing directional migration. To characterize droplet deformation, the maximum deformation coefficient (β) is introduced, and it consistently varies with the average migration velocity (). The effects of vibration parameters, surface area fraction, droplet volume, and surface tension on and β are analyzed. Results indicate that the vibration deformation of droplets changes with vibration frequency. At the resonance frequency, the droplet exhibits significant stretching and spreading, resulting in a marked increase in . Furthermore, there exists an optimal amplitude at the resonance frequency. Additionally, reducing the solid area fraction significantly weakens contact line pinning, further increasing the and β. As the droplet volume and surface tension increase, both and β increase. Experimental results and theoretical analysis reveal a linear correlation between β and CaOh. This work provides theoretical and technical insights into controlling droplet migration, offering a new perspective for optimization in industrial applications.
在诸如冷凝传热、抑霜和雾收集等工业应用中，处于文泽尔状态的液滴对表面表现出很强的附着力，阻碍其迁移。为了防止润湿转变并改善液滴迁移，本文提出了一种结合润湿性梯度、液体注入和机械振动的新方法。通过光刻在硅片上制备具有梯度润湿性的弯曲微槽表面，然后注入硅油形成液体注入表面。随后，施加垂直振动以诱导液滴变形，增强定向迁移。为了表征液滴变形，引入了最大变形系数（β），并且它与平均迁移速度（）一致变化。分析了振动参数、表面积分数、液滴体积和表面张力对和β的影响。结果表明，液滴的振动变形随振动频率而变化。在共振频率下，液滴表现出明显的拉伸和扩展，导致显著增加。此外，在共振频率下存在一个最佳振幅。此外，降低固体面积分数会显著削弱接触线钉扎，进一步增加和β。随着液滴体积和表面张力的增加，和β都增加。实验结果和理论分析揭示了β与CaOh之间的线性相关性。这项工作为控制液滴迁移提供了理论和技术见解，为工业应用中的优化提供了新的视角。
