【作者】 张连斌；

【导师】 沈家骢； 孙俊奇；

【作者基本信息】 吉林大学 ， 高分子化学与物理， 2010， 博士

【摘要】 随着层层组装技术(Layer-by-layer assembly technique)二十多年来发展,其作为一种简单、有效的膜材料制备技术已经被人们所广泛的接受。层层组装技术的众多优点,如可以在非平面基底大面积的制备多层膜,膜材料的结构与组成的可调控性等都是其他膜材料制备技术所无法企及的。因此,充分发挥层层组装技术在制备多层膜材料方面的优势对于功能性膜材料的制备意义重大。更为重要的是层层组装技术可以方便的通过改变构筑基元的种类和多层膜沉积过程并结合后处理等手段来方便的调控膜材料的化学组成与微观结构,这也为获得集多种功能于一身的多层膜材料提供了可能。本论文旨在利用层层组装技术构筑多层膜方面的灵活性以及结合对多层膜的后处理等方法制备集多种功能于一身的膜材料,主要包括以下三个方面:(1)利用聚阳离子PDDA和水玻璃sodium silicate在具有微米尺度结构的SiO2微球覆盖的基底表面上的交替沉积,得到了具有微纳米复合结构的表面,经过低表面能含氟硅烷偶联剂修饰后,获得了滚动角为3°,接触角为157°的超疏水表面;接下来进一步将这种制备超疏水表面的方法拓展到具有超疏水性质的近红外减反射膜的制备中,并证明了超疏水性能的引入可以有效的抑制多孔膜对水汽的吸收,从而保证这种多孔近红外减反射膜在相对湿度较大的环境中的使用性能。(2)利用聚阳离子PDDA与水玻璃silicate形成的带有正电荷的聚电解质复合物与聚丙烯酸PAA交替沉积,经过煅烧除去膜中的有机组分后,我们得到了具有高机械稳定性的防雾减反射膜材料。(3)利用刚性构筑基元TiO2纳米粒子与水玻璃silicate的交替沉积以及在多层膜的制备过程中采用非干燥的沉积过程得到了具有高度多孔结构的silicate/TiO2多层膜,这种高度多孔的silicate/TiO2膜材料可以作为涂层型吸附剂用于水中阳离子型染料污染物的吸附,吸附染料后的多层膜可以方便地通过紫外光照射进行恢复再生,并可重复多次使用。另外,采用原位AFM对多孔silicate/TiO2多层膜的形成过程的研究表明采用当前的这种非干燥的层层组装过程以及刚性的构筑基元对于克服层层组装过程中的自洽作用,形成高度多孔的结构是至关重要的。这一研究也为通过层层组装的方法直接获得多孔膜材料提供了一条新的途径。更多还原

【Abstract】 The layer-by-layer (LbL) assembly technique has been proven to be a promising method to fabricate various kinds of coatings with well-tailored chemical compositions and architectures on the micro- and nanoscales. The LbL assembly technique for coating fabrication mainly involves multiple dipping, water rinsing and drying steps, which is easy for large-scale production. The versatility of the LbL approach has allowed a broad range of materials (e.g., polymers, nanoparticles, lipids, proteins, dye molecules) to be assembled on various substrates, on the basis of not only electrostatic interactions but also hydrogen bonding, hydrophobic interactions, covalent bonding, and complementary base pairing. During the past decades, although much attention has been paid on this effective multilayer fabrication method, it remains a big challenge for the fabrication of the functionalized especially the multi-funcion integrated LbL assembled multilayer film. In this dissertation, we focus on the fabrication of multi-function integrated LbL assembled films, mainly includes the following aspects:In Chapter 2, a facile method for preparing a superhydrophobic surface was first developed by layer-by-layer deposition of poly(diallyldimethylammonium chloride) (PDDA)/sodium silicate multilayer films on a silica-sphere-coated substrate followed with a fluorination treatment. First, a silica-sphere-coated substrate that contains loosely stacked silica spheres of 600 and 220 nm was prepared and cross-linked with SiCl4. PDDA was then alternately assembled with sodium silicate on the silica-sphere-coated surface to prepare a micro- and nanostructured hierarchical surface. After chemical vapor deposition of a layer of fluoroalkylsilane, a superhydrophobic surface with a water contact angle of 157.1°and sliding angle of 3.1°was successfully fabricated. Then, we extend this method of fabrication of a superhydrophobic surface to the preparation of a broad-band superhydrophobic antireflective (AR) coatings in near infrared (NIR) region. The introduction of superhydrophobicity endows the AR coating with the water-repellent ability and makes the resultant AR coating applicable under humid environments. Additionally, the present method for preparing superhydrophobic AR coatings has the advantage of simplicity in fabrication, easy availability of the materials, and applicability to prepare large area coating on non-flat surface. Potential applications of this kind of superhydrophobic AR coatings in areas such as NIR analysis, NIR sensors and so forth are highly anticipated.In Chapter 3, we reported a facile and cost-effective method for the fabrication of mechanically stable antireflection and antifogging silica coatings by LbL deposition of PDDA&silicate complexes with PAA on quartz substrates followed by calcination. Calcination removed the organic components in PAA/PDDA&silicate multilayer films and introduced three-dimensional nanopores in the resultant silica coatings. In this way, highly porous silica coatings with a reduced refractive index and superhydrophilic properties can be fabricated simultaneously, which can be used as multifunctional AR and antifogging coatings. Calcination cross-linked the resultant silica coatings via the formation of stable siloxane bridges, which endows the AR and antifogging coatings with high mechanical stability and excellent adhesion to the substrates. We believe that the AR and antifogging silica coatings with a high durability can be widely useful in the production of eyeglasses, swimming goggles, periscopes, lenses in laparoscopic and gastroscopic surgery, and so forth.In chapter 4, we developed a facile and cost-effective method to the direct fabrication of highly porous TiO2 coatings by non-drying LbL deposition of sodium silicate and TiO2 nanoparticles without any post treatment. The rigid nature of sodium silicate and the non-drying LbL deposition process are critically important to prohibit the self-healing and lead to the formation of porous TiO2 coatings. Meanwhile, the present method is suitable for the fabrication of large-area porous TiO2 coatings on substrates with complicated morphologies. The as-fabricated porous TiO2 coatings, which can be easily recovered through UV irradiation for recycling usage, show a good ability to remove organic pollutants in wastewater because of their high porosity. The present study creates a novel route of using rigid building blocks and non-drying LbL assembly to prohibit self-healing for the direct fabrication of porous coatings, which we believe to be useful to fabricate other kinds of functional porous coatings.更多还原