高性能微/纳米结构不粘薄膜的制备及研究

【作者】 陈志；

【导师】 耿兴国；

【作者基本信息】 西北工业大学 ， 材料物理与化学， 2005， 硕士

【摘要】 润湿性是固体表面的重要特征之一,也是最常见的一种界面现象,在工农业生产上和人们的日常生活中起着非常重要的作用。而通过表面化学组成和表面微/纳米结构的构建实现固体表面的超疏性能,正成为人们研究的热点之一。 本论文主要研究工作如下: 1.通过大量的不粘性能试验和相应的表面微结构观察测量,揭示了具有超疏性能的表面微/纳米优化结构特征。从而通过改变表面的表面能和不均匀性,可以使液体与固体表面接触角发生变化,并用接触角测量仪、原子力显微镜、扫描电镜等仪器,分析了改性后的金属表面的不粘性能的优劣。同时还说明了极小的滚动角也是衡量超疏表面的一个重要标准。 2.通过理论分析和模型构建,进一步定量刻画了具有优化微结构的不粘薄膜超疏机理。模型分析发现,理想的超疏结构应尽可能使柱宽与柱高的比值(a/H)尽可能的小。同时还给出了一滴液滴是否处于稳定的Wenzel状态还是Cassie状态的吉布斯函数判定依据,并用化学吸附理论和实验分析了氟硅烷分子在微/纳米结构上形成FAS-SAMS膜的特征,表明氟硅烷分子的特殊结构决定了其具有极低的表面能和垂直于基底生长的三维网状结构。 3.探索了用化学腐蚀方法和阳极氧化法在金属表面构建微/纳米结构及氟硅烷薄膜制备的实验规律,为进一步改进其方法和应用到工程应用中解决不粘等问题打下基础。所研制出的超疏薄膜配方及技术,可在金属表面制备出超疏薄膜。 4.分析论证了微/纳米结构和低表面能的氟硅烷薄膜对不粘性能的协同作用。计算出改性后的铝片等效临界表面张力为1mN/m左右,并用CB方程计算出改性后阳极氧化的铝片气/液和固/液接触面在复合接触面中所占比例,分别为0.93和0.07。进一步验证了改性后金属表面疏液性是由低表面能氟硅烷薄膜和微细结构共同决定的。 5.研制出新的工程应用型涂层实现金属表面的不粘改性,测得所制常温固化涂层性能与常规聚四氟乙烯的不粘性能相当,为不粘薄膜的实用化指明了方向。更多还原

【Abstract】 Wettability is an important properties of solid surface, and is the most common kind of interface phenomenon too. It plays a very important role in industrial and agricultural production and in daily life. Changing the surface chemistry and forming micro/nano- structures surface to realize superhydrophobic properties of solid surface is attracting more and more interest from people. The principle work is as follows:1. Through a lot of anti-sticking test and corresponding micro- structure of surface to be observed, it is found that superhydrophobic surface had optimum micro/nano- structures of characteristic. By changing surface free energy and heterogenousity of surface, it can make contact angles of liquid and solid surface change, and it can use contact angles measuring apparatus atomic force microscopy (AFM) and Scanning Electron Microscope (SEM) etc. to observe and analyse the anti-sticking performance of modified metal surface, and decide which is good or bad. At the same time, it is explained that little roll-off angles is an important standard to superhydrophobic surface.2. By theory analysis and model proposed, the superhydrophobicty mechanism of anti-sticking films, which is further described. In analysing models, it found that superhydrophobic structure should make the value ratio of post wide and post high(a/H) little possibly. On the basis of Gibbs function of state, which can decide one drop is in a steady Wenzel state or Cassie, and using chemistry absorption theory and experiment analysis explain the FAS-SAMS forming mechanism of fluoroalkyl silanes on the micro/nano structures, it indicates that special molecule structure of fluoroalkyl silanes has low surface energy and three-dimension netted structure by vertical growing on the substrate.3. It is explored experiment law of creating micro/nano- structures in metal surface by chemistry corroding and oxidize methods and preparing fluoroalkyl silanes films, it is to be the foundation for further improving its method and applying to the project to solve the problem of anti-sticking. The researched prescription and technology of superhydrophobic thin films can prepare superhydrophobic thin films on metal surface.4. It is analysed and proved that micro/nano- structures and fluoroalkyl silanes with low surface energy have the cooperative effect to anti-sticking performance. Calculating out the critical surface energy of modified aluminium is about 1mN/m, Gas/liquid contact surface and solid/liquid contact surface about compound surface of modified anodization and gas, which is 0.93 and 0.07 respectively by CB state calculating. It is future proved that micro/nano- structures and fluoroalkyl silanes films with low surface energy altogether decided lyophobicitv of modified metal surface;5. Developed some new coatings for engineering application, it is tested that the performance of modified metal surface at room temperature coatings is as the same as of routine Polytotra fluorethylene (PTFE), it is to point out the direction of use in daily practically for anti-sticking films.更多还原