超声刻蚀法构建分级结构的超疏水表面

在湿法刻蚀和超声空化的基础上, 采用超声刻蚀法制备了具有微纳米分级结构的超疏水表面. 以等体积比的硝酸/乙醇(体积分数为4%)和双氧水(质量分数为30%)的混合溶液作为刻蚀剂, 在室温下对60Si2Mn钢、 60^#钢、 T10钢、 Cr06钢、 65Mn钢和硅钢表面超声刻蚀2~10 min, 构建出多种形貌的微纳米分级结构. 上述表面经氟硅烷修饰后具有超疏水性, 水的表观接触角高达157.0°, 155.8°, 157.4°, 154.9°, 157.6°和156.8°, 滚动角分别为6.5°, 19.2°, 6.1°, 7.8°, 6.7°和7.2°. 与常规刻蚀方法相比, 超声刻蚀的化学刻蚀作用因与空化作用耦合而得到强化和改变, 从而在钢表面构建出分级结构. 由于材料表面微结构形貌和固/液界面接触状态不同, 制得的超疏水表面表现出的润湿行为也不同. 超声刻蚀法简单易行, 成本低廉, 适用于其它金属表面构建微纳米分级结构和超疏水表面.

Fabrication of Superhydrophobic Surfaces with Hierarchical Structures by an Ultrasonic Etch Method†

Based on wet etching and ultrasonic cavitation, an ultrasonic etch method was proposed for fabricating micro- and nanoscale hierarchical structures. By ultrasonic etching with isopyknic mixture of nitric acid/ethanol(4%, volume fraction) and hydrogen peroxide(30%, mass fraction) for 2—10 min at room tempe-rature, several hierarchical structures were fabricated on the surfaces of 60Si2Mn, 60^#, T10, Cr06, 65Mn and silicon steel. After decorated with fluorosilane, the aforementioned surfaces become superhydrophobic and show water contact angles of 156.0°, 154.8°, 156.4°, 153.9°, 156.6° and 155.8°, respectively, and the corresponding roll angles are 6.5°, 19.2°, 6.1°, 7.8°, 6.7° and 7.2°, respectively. Compared to the regular etching, the chemical corrosion of ultrasonic etching was enhanced and modified by coupling with cavita-tion, and therefore could fabricate hierarchical structures. Due to the differences in microstructure morphologies and wetting states of solid/liquid interfaces, the superhydrophobic surfaces prepared show different wetting behavior. The ultrasonic method proposed is simple, inexpensive and available for other metals, thus having potential values in constructing micro- and nanoscale hierarchical structures and superhydrophobic surfaces.