A Dynamically Responsive Surface with Switchable Wettability for Efficient Evaporation and Self-Cleaning Abilities
A Dynamically Responsive Surface with Switchable Wettability for Efficient Evaporation and Self-Cleaning Abilities
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DOI：
10.1021/acsaenm.2c00097
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发表时间：
2022-10
期刊：
影响因子：
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通讯作者：
Gregory Parisi;A. López;Shankar Narayan
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文献类型：
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作者：
Gregory Parisi;A. López;Shankar Narayan
蒸发在许多应用中至关重要。影响蒸发的关键参数之一是表面润湿性，其通常使用表面上的涂层和微米或纳米级特征来定制。虽然这种方法已经推进了许多技术，但动态控制润湿性的能力可以增加以前不可能实现的新功能和能力。这项研究展示了平衡接触角为155°的自清洁超疏水表面如何动态地改变为接触角接近0°的超亲水表面，从而产生截然不同的蒸发特性。具体来说，我们发现，由于所产生的冷却的蒸发速率和表面温度降低是3倍高，由于表面润湿性的变化。润湿行为的这种变化是由于使用氨基硅烷[N-（2-氨基乙基）-11-氨基十一烷基三甲氧基硅烷]官能化的表面，其在稀乙酸的存在下改变。在完全蒸发后，表面恢复到超疏水行为。这种可逆行为在传统的非润湿涂层如全氟癸基三氯硅烷和月桂酸中看不到。这种动态控制润湿性和蒸发的策略可以在许多应用中取得进步，从基于自组装的制造工艺到油水分离和先进的热管理技术。
Evaporation is crucial in many applications. One of the critical parameters affecting evaporation is surface wettability, which is often tailored using coatings and micro- or nanoscale features on the surface. While this approach has advanced many technologies, the ability to control wettability dynamically can add new functionalities and capabilities that were not possible before. This study demonstrates how a self-cleaning superhydrophobic surface with an equilibrium contact angle of 155° can dynamically change to a superhydrophilic surface with a contact angle near 0°, resulting in drastically different evaporation characteristics. Specifically, we find that the evaporation rate and surface temperature reduction due to the resulting cooling are 3 times higher due to the change in surface wettability. This change in wetting behavior is due to the use of an amino-silane [N-(2-aminoethyl)-11-aminoundecyltrimethoxysilane]-functionalized surface, which is altered in the presence of dilute acetic acid. Upon complete evaporation, the surface reverts to superhydrophobic behavior. This reversible behavior is not seen in traditional nonwetting coatings like perfluorodecyltrichlorosilane and lauric acid. This strategy for dynamic control of wettability and evaporation can lead to advancements in many applications ranging from self-assembly-based fabrication processes to oil–water separation and advanced thermal management technologies.