Wetting thresholds for long-lasting superwettability: From intrinsic wetting boundary to critical roughness value
Wetting thresholds for long-lasting superwettability: From intrinsic wetting boundary to critical roughness value
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DOI：
10.1016/j.cej.2022.140058
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发表时间：
2023-02
影响因子：
15.1
通讯作者：
Shaofan He;Zhongpeng Zhu;Bo Zhang;Ye Tian
中科院分区：
文献类型：
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作者：
Shaofan He;Zhongpeng Zhu;Bo Zhang;Ye Tian
制备超亲/疏液材料具有重要的理论意义和实际应用价值，但实现持久超润湿性的本征组分和表面粗糙度的界限尚未完全清楚。本文以硅纳米线（SiNW）表面为模型，通过系统地调节本征组分和表面粗糙度，研究了超润湿性的本征润湿边界（IWB）和临界粗糙度值（CRV）。考虑到表面极性的影响，我们定义了一个临界值，即表面极性分量与色散分量的比值。不同的液体对应不同的IWB反射临界f值，对于水，IWB反射f值在0.5左右。对于表面结构决定的CRV，粗糙度被定义为实际面积与投影面积的比值，SiNW达到超润湿性的CRV被测试为18左右（对应于1 μm SiNW），这是润湿行为从Wenzel状态到Cassie状态的转变点。通过这些阈值，实现了具有超扩散行为的持久超亲水性和具有超低粘附性的超疏水性，这为设计与实际应用相关的功能界面提供了重要指导，例如太阳能电池，微流体和电极。
Fabricating superlyophilic and superlyophobic materials is of great significance in both academic research and practical application, but the boundary thresholds of intrinsic composition and surface roughness to achieve long-lasting superwettability are not completely understood yet. Herein, silicon nanowire (SiNW) surfaces are chosen as a model to study the intrinsic wetting boundary (IWB) and critical roughness value (CRV) of superwettability by adjusting intrinsic composition and surface roughness systematically. Taking account of the influence of surface polarity, we define a criticalfvalue as the ratio of polar components of the surface to dispersive components. Different liquids correspond to different IWBs reflected criticalfvalues, for water, the IWB reflected infvalue is around 0.5. For surface structure determined CRV, roughness is defined as a ratio of actual area to projected area, and the CRV of SiNWs to reach superwettability is tested to be around 18 (corresponding to 1 μm SiNWs), which is the transition point of wetting behavior from Wenzel state to Cassie state. With these thresholds, long-lasting superhydrophilicity with superspreading behavior and superhydrophobicity with ultralow adhesion for contaminants are achieved, which provide significant guidance for designing functional interfaces related to practical applications such as solar cells, microfluidics and electrodes.