硅橡胶表面原位生长ZnO纳米花构筑稳固超疏水表面

Mechanically stable superhydrophobic surface fabricated by self-growth of ZnO nanoflowers on vulcanized silicone rubber

  • 摘要: 制造的复杂性和对机械接触的敏感性严重阻碍了超疏水材料在实际应用的发展。为在柔性基质(硫化的硅橡胶)表面制备机械耐久的柔性超疏水表面,利用硫化硅橡胶溶胀过程可逆的特性,改进溶胶-凝胶法,将硅橡胶片预先用正丁胺水溶液溶胀,然后浸入硝酸锌/乙醇溶液中。利用正丁胺水溶液和硝酸锌/乙醇溶液在硅橡胶表面的交互扩散、反应,使ZnO纳米花在橡胶表面原位生长。超疏水的粗糙结构的构筑来自于硝酸锌与正丁胺的协同作用,其静态接触角(CA)可达(158±1.5)°,滑动角(RA)可达(4.5±0.5)°。SEM图像显示,100~200 nm的ZnO纳米片生长在硅橡胶表面,ZnO纳米片“嵌入”到橡胶表面,而不是沉积在橡胶表面,因此提升了其机械耐久性。而通过向橡胶中添加硅烷偶联剂γ-氨丙基三乙氧基硅烷(KH550),可进一步提升ZnO纳米片与橡胶基体界面相互作用,即使承受300次线性磨损,仍能保持超疏水特性,表现出优异机械稳定性。而且经过500次循环弯曲变形,其疏水性也几乎没有变化,解决了超疏水涂层在基体弯曲变形时的脱落问题。这种超疏水橡胶制备技术简单且适合工业生产,具有极高的实用前景。

     

    Abstract: The development of superhydrophobic materials in practical applications has been severely hindered by the complexity of manufacturing and the sensitivity to mechanical contact. In order to prepare a mechanically durable flexible super-hydrophobic surface on the surface of a flexible substrate (vulcanized silicone rubber), using the reversible characteristics of the swelling process of vulcanized silicone rubber and the improved sol-gel method, the silicone rubber sheet was swelled with a n-butylamine aqueous solution in advance, and then immersed in zinc nitrate/ethanol solution. Due to the cross-diffusion, contact and reaction between zinc nitrate and n-butylamine aqueous solution on the surface of silicone rubber, ZnO nanoflowers were grown in-situ on the rubber surface. The construction of the superhydrophobic rough structure came from the synergistic effect of zinc nitrate and n-butylamine, with static contact angle and rolling angle being (158±1.5)° and (4.5±0.5)° respectively. SEM images show that ZnO nanosheets of 100-200 nm in thickness are generated and the ZnO nanosheets are “embedded”, not just “deposited” on the rubber surface, which improves the mechanical durability. By adding a silane coupling agent γ-aminopropyltriethoxysilane (KH550) to the silicone rubber compounds, the interface interaction between the ZnO nanosheets and the rubber matrix is further improved. Even with 300 times of linear wear, it could still maintain superhydrophobic and exhibit excellent mechanical stability. Moreover, after 500 cycles of bending deformation, its hydrophobicity hardly changes, which solves the problem of superhydrophobic coating falling off when the substrate is bent and deformed. High mechanical stability and simple preparation process endow the superhydrophobic rubber a high application prospect.

     

/

返回文章
返回