Liu Wendong, Xiang Siyuan, Liu Xueyao, Yang Bai
State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun 130012, People's Republic of China.
Max Planck Institute for Polymer Research, Ackermannweg 10, D-55128 Mainz, Germany.
ACS Nano. 2020 Jul 28;14(7):9166-9175. doi: 10.1021/acsnano.0c04670. Epub 2020 Jul 15.
A superantiwetting surface based on low-aspect-ratio hierarchical cylinder arrays (HCAs) was successfully obtained on a silica substrate by colloidal lithography with photolithography. Colloidal lithography is a technique involving transfer of a pattern to a substrate by etching or exposure to a radiation source through a mask composed of a packed colloidal crystal, while photolithography is utilized by which a pattern is transferred photographically to a photoresist-coated substrate, and the substrate is subsequently etched. The surface provides an alternative approach to apply aligned micro-nano integrated structures with a relatively low aspect ratio in superantiwetting. The obtained HCAs successfully integrated micro- and nanoscale structures into one system, and the physical structure of the HCAs can be tuned by modulating the fabrication approach. Using a postmodification process, the underwater-oil wetting behavior of cylinder-array based surfaces can be easily modulated from the superoleophobic state (an oil contact angle (OCA) of 161°) to oleophilic state (an OCA of 19°). Moreover, the underwater-oil wettability can be reversibly transformed from the superoleophobic state (an OCA of approximately 153°) into the oleophilic state (an OCA of approximately 31°) by grafting stimuli-responsive polymer (PNIPAAm) brushes onto this specific hierarchical structure. Due to the temperature-responsive property, modifying the surface with PNIPAAm provides a possibility to control the oil wettability (repellent or sticky) by temperature, which will benefit the use of HCAs in oil-water separation and other application fields.
通过胶体光刻结合光刻技术，在二氧化硅基底上成功制备了一种基于低纵横比分级圆柱阵列（HCAs）的超疏水表面。胶体光刻是一种通过蚀刻或通过由紧密堆积的胶体晶体组成的掩模暴露于辐射源将图案转移到基底上的技术，而光刻则是利用该技术将图案通过照相方式转移到涂有光刻胶的基底上，随后对基底进行蚀刻。该表面为在超疏水领域应用具有相对低纵横比的排列微纳集成结构提供了一种替代方法。所获得的HCAs成功地将微米和纳米级结构集成到一个系统中，并且可以通过调节制造方法来调整HCAs的物理结构。使用后修饰工艺，可以轻松地将基于圆柱阵列的表面的水下油润湿性从超疏油状态（油接触角（OCA）为161°）调节到亲油状态（OCA为19°）。此外，通过将刺激响应性聚合物（PNIPAAm）刷接枝到这种特定的分级结构上，水下油润湿性可以从超疏油状态（OCA约为153°）可逆地转变为亲油状态（OCA约为31°）。由于温度响应特性，用PNIPAAm修饰表面提供了通过温度控制油润湿性（排斥或粘性）的可能性，这将有利于HCAs在油水分离和其他应用领域的使用。
