利用两种粒径的二氧化硅体系制备超疏水表面(英文)

A Superhydrophobic Surface Prepared by the Combination of Two Sizes of Silica Particles

利用Stber方法制备了粒径为550 nm的二氧化硅小球和粒径为10nm的二氧化硅溶胶。通过两步提拉法得到了其有类似荷叶表面的微米-纳米结构的超疏水表面。二氧化硅小球的分散性对形成此二元结构具有重要影响。通过六甲基二硅氮烷对溶胶的修饰,所得到的薄膜无需经后续处理即可表现出超疏水性质。此方法相对于三甲基氯硅烷对薄膜的后处理能得到更加优异的疏水性。最终得到的超疏水表面是均匀的二元结构和较低的表面自由能共同作用的结果,在此表面上疏水角可达170°。

A superhydrophobic surface with the lotus' leaf-like structure was prepared by combining two silica systems derived from Stober process.The two silica systems are microsphere suspension with the particle size of 550 nm and sol with the particle size of10 nm separately.The combination of the two silica systems are realized by a two-step dipping process that endows the surface a micro-nanostructure and low surface free energy.The resulting surface presents perfect water repellence with water contact angle of about 170°.The whole process of preparation just costs about 2 min due to the omission of any post treatment.This method also applies for large and curved surfaces that make it possible for industrial application.The good dispersity of the silica microspheres is very important for the formation of the binary structure and the chemical modification in the silica sol is decisive to the eventual hydrophobicity.The impacts of structure and chemical composition were discussed in detail.