Study Of The Controllability Of Solid Surface Wettability In Liquid

Recently, superwetting materials become a new research focus due to their wide applications. As research progressed, research about superwetting materials has beyond those surfaces with superhydrophobicity/superhydrophilicity in air. Research about surface wettability in complex environment has also aroused much attention. These surfaces have many potential applications, such as anticorrosion, antifouling, and oil/water separation. Thus, herein, we focused on the control of solid surface wetting performances in liquid phase(water or oil), and the concrete works can be summarized as following.1, Fabrication of underwater superoleophobic surfaces on smooth surface through a simple O2 plasma process. After O2 plasma, it is found that the number of hydroxyl groups on the silicon surface is increased apparently, as a result, the hydration of the surface can be enhanced, and a network of water film can be formed on the surface through the hydrogen bond. The formed water film can effectively impede the contact between the oil droplet and the solid surface, therefore, the surface shows special low adhesive underwater superoleophobicity. Meanwhile, such superoleophobicity is universal and suitable to various oils. More importantly, the surfaces also shows special robustness for the wetting performance, which can tolerant to various insults including anti-extrusion, acid/basic-resistance, etc., Furthermore, we also extend the method to some other flat substrates, such as gold, silver, copper, glass and quartz, and advanced some applications.2, Fabrication of smart silicon surface that can transit reversibly between the underoil superhydrophobicity and the underoil superhydrophilicity. The original micropillar-structured silicon surface shows underoil superhydrophobicity, after O2 plasma treating, it becomes underoil superhydrophilicity. Further heating the surface at 500 ℃ for about 6 h under N2, the surface would return to the initial underoil superhydrophobic state. The O2 plasma and heating processes can enhance and weaken the surface hydration, respectively. Combined with the amplified effect of rough structure, reversible transition between the two extreme states can be realized on the surface. Given the surface has such a smart ability, it can potential be used in many applications, such as water capture in oil.3, One-solution immersion process for the fabrication of surfaces with tunable wettability from underwater superoleophobicity to superoleophilicity. Glass slides covered with a thin copper membrane were immersed into ethane solution containing 1mM octadecanoic acid. By simply changing the immersion time, different microstructures can be obtained on the surfaces, accordingly, transition from underwater superoleophobicity to underwater superoleophilicity can be achieved. Noticeably, these surfaces can remain the wetting performance in air more than 10 days without special protection, demonstrating a stable chemical property. Research results indicate that the variation of surface wettabiltiy is ascribed to different wetting states caused by the different microstructures on the surfaces.