强黏附性超疏水氧化铝的表面结构和黏附机理

Structure and Adhesive Mechanism of Superhydrophobic Alumina Surface with High Adhesive Force

以三丁醇铝为前驱体,采用溶胶-凝胶法和浸涂法制备得到氧化铝凝胶薄膜。再通过沸水处理、热处理和表面接枝聚乙烯亚胺和硬脂酸等工艺,获得了一种既具有超疏水特性又呈现出强黏附力的氧化铝薄膜。利用傅里叶变换红外光谱(FTIR)、场发射扫描电子显微镜(FE-SEM)、X射线衍射(XRD)和接触角测试等技术对薄膜表面的化学组成、形貌、结构和润湿性能及其黏附性等进行了考察。结果表明:所研制的氧化铝表面由多孔的花瓣状粗糙结构和独特的疏水长链单分子层构成。水滴可以润湿粗糙表面上较大尺度的凹槽,而不能浸润较小尺度的凹槽,从而使得这种氧化铝表面既呈现出很高的接触角,又具有较强的黏附特性。

Alumina gel film was prepared by the sol-gel and dip-coating method using Al（O-sec-Bu）3 as a precursor. Then an alumina film with both superhydrophobicity and high adhesive force was fabrica- ted by treatment procedures as heat, boiling water, and surface modification with PEI and STA. The chemical composition, morphology, structure, and wettability of the superhydrophobic surface were investigated by techniques as FTIR, FE-SEM, XRD, and contact angle measurement. Results show that the alumina surface is made up of the porous flowerlike structure coated with a layer of long hy- drophobic alkyl chains. Water is expected to enter into the large scale grooves of the rough alumina surface, but it can not enter into the small scale ones. Consequently, the alumina surface shows both high contact angle and strong adhesion.