玻璃及织物上疏水膜的自组装制备及耐久性评价

发布时间：2018-08-29 15:15

【摘要】：疏水表面是与水的接触角大于90°的表面,由于其潜在的实际应用引起了广泛关注。过去的几十年,通过模仿大自然的荷叶等表面结构,在制备人工疏水表面方面进行了各种尝试。然而,鲜有产品推出。究其原因是由于其耐久性差、制作成本高等诸因素制约着该领域的发展。固体表面的润湿性是由表面的化学组成和表面形貌共同决定的,因此通过改变固体的表面自由能和表面形貌可以实现对固体材料表面润湿性的控制。由于单纯的低表面能物质所能达到的疏水程度是有限的,特别是玻璃、纺织品等量大面广的材料,如何使硅烷、氟硅烷等低表面硅牢固结合在基材上也是迫切要解决的问题。纳米SiO_2制备工艺成熟,有硅溶胶、白炭、墨等多种商品出售。本文结合层层自组装及疏水改性在应用广泛的玻璃及纺织品表面制备了疏水膜,并通过一系列实验对薄膜的耐久性进行了综合评价。论文的主要工作有:(1)以纳米二氧化硅溶胶为主要原料,通过层层自组装的方法构造纳米二氧化硅薄膜,经热处理使膜层与玻璃基底牢固结合,获得透过率高、耐久性好的多孔纳米二氧化硅薄膜。通过调节自组装层数来改变薄膜的厚度,富含硅羟基的自组装膜增加了低表面能物质与玻璃的结合力,得到了疏水性更好的薄膜,含25层SiO_2膜可使接触角由110°提高到150°,对该疏水膜进行了雨刮器模拟测试、砂砾摩擦测试等破坏性测试,含自组装膜的疏水层耐久性明显提高。(2)以棉布、尼龙、涤纶等亲水性织物为基材,对其进行疏水性处理使其由亲水性转变为疏水性。通过羟基化预处理使织物表面富含羟基,采用硅酸钠为原料自组装二氧化硅薄膜,然后利用预水解的低表面能的氟硅烷接枝,制得疏水织物。通过耐洗涤、耐老化、耐摩擦实验评价其耐久性能,活化处理及SiO_2薄膜提高了其耐久性。(3)采用全纳米颗粒自组装的方法,分别以二氧化钛溶胶和二氧化硅溶胶为原料,层层自组装制备复合纳米薄膜,纳米二氧化钛半导体常用于织物抗紫外剂。但由于纳米TiO_2活性高、易团聚,影响产品的性能,结合二氧化硅,可抑制其高活性。二者交替沉积,制备纳米复合薄膜,在降低其活性的同时,还可以提高耐久性。再经不含氟的低表面能物质十六烷基三甲基硅烷修饰,获得疏水性好的织物,织物的接触角可达172o,紫外光区的吸光度成倍提高。并对其进行耐老化、耐摩擦、耐水流冲击等耐久性试验,对比破坏性实验前后各种性能的变化,评价其耐久性。
[Abstract]:Hydrophobic surface is a surface whose contact angle with water is greater than 90 掳. In the past few decades, artificial hydrophobic surfaces have been prepared by imitating nature's lotus leaves and other surface structures. However, few products are available. The reason is that the development of this field is restricted by such factors as poor durability and high production cost. The wettability of solid surface is determined by the chemical composition and surface morphology of solid surface, so the wettability of solid material can be controlled by changing the surface free energy and surface morphology. Because the hydrophobic degree of pure low surface energy material is limited, especially glass, textile and so on, how to make silane, fluorosilane and other low surface silicon firmly combine on the substrate is also an urgent problem to be solved. Nano-SiO_2 preparation technology mature, silica sol, white carbon, ink and other commodities for sale. In this paper, hydrophobic films were prepared on glass and textile surfaces with layer by layer self-assembly and hydrophobic modification. The durability of the films was evaluated by a series of experiments. The main work of this paper is as follows: (1) Nano-silica thin films are constructed by layer self-assembly using nano-silica sol as the main raw material. After heat treatment, the films are firmly combined with glass substrates to obtain high transmittance. Porous nano silica film with good durability. By adjusting the number of self-assembled layers to change the thickness of the film, the self-assembled film with rich silica hydroxyl increases the binding force between the low surface energy substance and the glass, resulting in a better hydrophobic film. The contact angle of the hydrophobic film was increased from 110 掳to 150 掳with 25 layers of SiO_2 film. The hydrophobic film was tested by wiper simulation test, sand gravel friction test and other destructive tests. The durability of the hydrophobic layer containing self-assembled film was improved obviously. (2) the durability of the hydrophobic layer containing cotton cloth and nylon was improved obviously. Polyester and other hydrophilic fabrics were treated with hydrophobicity to change from hydrophilicity to hydrophobicity. The surface of the fabric is rich in hydroxyl by hydroxylation pretreatment. The hydrophobic fabric is prepared by using sodium silicate as the raw material to self-assemble the silica film, and then the hydrophobic fabric is prepared by grafting the hydrophobic low surface energy fluorosilane. The durability was evaluated by washing resistance, aging resistance and friction resistance test. The durability was improved by activation treatment and SiO_2 thin film. (3) Titanium dioxide sol and silica sol were used as raw materials, respectively. Composite nano-films were prepared by self-assembly. Nano-titanium dioxide semiconductors are often used as anti-UV agents for fabrics. However, because of its high activity and easy agglomeration, nanometer TiO_2 can inhibit its high activity by combining with silica. The nanometer composite film can be prepared by alternating deposition of the two films, which can decrease the activity and improve the durability at the same time. After modification with hexadecyl trimethylsilane, a low surface energy substance without fluorine, a good hydrophobic fabric was obtained. The contact angle of the fabric was 172o. the absorbance of the ultraviolet region was increased exponentially. The durability tests such as aging resistance, friction resistance, water flow impact resistance and so on were carried out. The durability was evaluated by comparing the changes of various properties before and after destructive test.
【学位授予单位】：东华大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TB383.2

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