Department of Mechanical Engineering, Hong Kong University of Science and Technology, Clearwater Bay, Kowloon, Hong Kong SAR, PR China.
ACS Appl Mater Interfaces. 2012 Jan;4(1):273-9. doi: 10.1021/am2013129. Epub 2011 Dec 27.
A hierarchical copper structure combining micro- and nanogaps/pores was built up on copper substrate by etching and electrodeposition. The fresh as-deposited copper was easily oxidized in air at room temperature, forming a CuO layer covering on the surface. The surface could be hydrophobized with thiol-modified fluorocarbons, after which it showed a water contact angle as high as 165° ± 2°. This surface could also regain the superhydrophilicity with a zero water contact angel after annealing at 200 °C for 10 min to desorb the low surface energy monolayer of thiol-modified fluorocarbons and reform a CuO layer again on the surface. Repeating the process of adsorption/desorption of the monolayer by modification and annealing, it was successful to fulfill the wettability cycling between superhydrophobicity and superhydrophilicity on the copper surface. The adsorption and desorption mechanism of the monolayer was discussed based on the result of surface chemistry analysis.
在铜基底上通过刻蚀和电沉积构建了一种结合微纳间隙/孔的分层铜结构。新鲜沉积的铜在室温下很容易被空气中的氧气氧化，在表面形成一层氧化铜覆盖层。表面可以用硫醇改性氟碳化合物进行疏水处理，处理后的表面水接触角高达 165°±2°。经过 200°C 退火 10 分钟以解吸硫醇改性氟碳化合物的低表面能单层并在表面再次形成氧化铜层，表面可以恢复超亲水性，水接触角变为 0°。通过修饰和退火重复单层的吸附/解吸过程，可以成功地实现铜表面超疏水性和超亲水性之间的润湿性循环。根据表面化学分析的结果，讨论了单层的吸附和解吸机制。
