胶体光子晶体薄膜的规模化制备及应用

发布时间：2018-04-29 06:08

  本文选题：胶体光子晶体薄膜 + 规模化制备　； 参考：《华东师范大学》2017年硕士论文

【摘要】：胶体光子晶体是由单分散微米或亚微米级别的有机和无机胶体颗粒在重力、电场力、磁场力、剪切力或者毛细作用下组装形成的二维或三维有序结构。胶体光子晶体因其周期性的有序排列而具有特殊的光电性质。因此,它在光学器件、光子晶体墨水、光子晶体印刷、染料、感应器、光电池和光催化材料等多方面具有应用价值。在胶体光子晶体领域,新型结构基元的匮乏是一个亟待解决的问题。最常见的光子晶体结构基元是二氧化硅(SiO_2)和聚苯乙烯胶体颗粒(PS),但是这两种物质的折射率较低,一定程度上限制了胶体光子晶体的应用范围。近年来,为了获得性能更加优越的胶体光子晶体,金属氧化物及半导体材料已经开始被用来合成新型的光子晶体结构基元。例如:Fe_3O_4、ZnS、ZnO、Cu_2O、Al_2O_3和TiO_2等。由于这些物质分别具有不同的化学性质,赋予了光子晶体更多的应用方向。此外,高效、经济、规模化的组装方法也是胶体光子晶体材料研究的关键。在过去十年中,人们通常采用垂直沉降法、浸渍提拉法、微乳流法、反相蛋白石法、震荡剪切法、旋涂法、以及受热力、磁场力和电场力诱导的组装方法来制备胶体光子晶体。虽然这些方法都能满足实验室规模的组装和应用,然而面向实际生产应用,我们必须开发更加高效的方法来实现光子晶体的规模化制备。本论文从新型光子晶体结构基元的合成和组装方法的探索这两方面展开研究。在第一个工作中,我们利用种子生长两步法合成了高度单分散、尺寸均匀可调的ZnO胶体颗粒,并通过挥发、浓缩和旋涂的过程将ZnO胶体颗粒组装成有序的胶体光子晶体薄膜。我们在保证胶体颗均匀度和稳定性的条件下可将合成体系扩大到1.5 mL,所合成的ZnO光子晶体薄具有明亮、饱和的结构色与均匀有序的内部结构。与无序的ZnO薄膜相比,有序的ZnO胶体光子晶体薄膜具有更高的光利用效率和更加优越的光电性质,并且在长时间的反应中可以保持良好的稳定性和光催化活性。将焙烧后的有序、无序ZnO胶体光子晶体薄膜应于光催化还原CO2,我们发现当光禁带与电子吸收能带相匹配时,ZnO胶体光子晶体薄膜具有更高的光催化活性。在这项工作,我们通过旋涂法合成了具有优越光催化活性的ZnO胶体光子晶体薄膜,实现了基于光子晶体结构光催化剂的规模化制备,为光子晶体在光催化领域中的应用奠定了基础。第二项工作中,我们利用LBL技术合成了具有超顺磁性质的复合纳米颗粒,并在溶剂挥发诱导和磁组装的协同作用下实现了胶体光子晶体薄膜的规模化制备。我们通过静电吸附作用依次将PEI和Fe_3O_4修饰在PS的表面,然后再包裹一层SiO_2。这种PS@PEI@Fe_3O_4@SiO_2胶体颗粒不仅尺寸可调、分布较窄,并且可以一次性进行大量的合成,为后续的组装奠定了良好的基础。我们通过调节PS的尺寸和SiO_2的厚度可以得到280 nm～450 nm的胶体颗粒,利用不同尺寸的胶体颗粒可以在磁场下组装出具有不同饱和结构色的光子晶体薄膜。此外,我们通过可见-近红外反射光谱证明了光子晶体薄膜高度均匀,并发现了薄膜干涉现象。最终,我们通过连续注入浓缩液的方式在亲水基底上进行了光子晶体薄膜的连续制备,仅仅利用12分钟就获得了长100cm、宽2cm的光子晶体胶带。整个组装过程不仅绿色环保、快速高效和节省原料,并且适用于多种日常生活中常见的基质材料,为光子晶体薄膜的应用提供了保障。
[Abstract]:Colloidal photonic crystal is a two-dimensional or three-dimensional ordered structure composed of organic and inorganic colloidal particles of monodisperse or submicron levels of organic and inorganic colloids under the action of gravity, electric field force, magnetic field force, shear force, or capillary action. Colloidal photonic crystals have special photoelectric properties because of their periodic ordered arrangement. Therefore, it is in optical devices and light. Crystal inks, photonic crystal printing, dyes, sensors, photocell and photocatalytic materials have many applications. In the field of colloidal photonic crystals, the lack of new structural elements is a problem to be solved urgently. The most common photonic crystal structure is two silicon oxide (SiO_2) and polystyrene colloid particles (PS), but this two In recent years, metal oxide and semiconductor materials have been used to synthesize new photonic crystal structure elements, such as Fe_3O_4, ZnS, ZnO, Cu_2O, Al_2O_3 and TiO_2. Some substances have different chemical properties respectively, which give more direction to the application of photonic crystals. In addition, high efficiency, economic and large-scale assembly method is also the key to the research of colloidal photonic crystal materials. In the past ten years, people usually use vertical settlement, impregnation drawing, microemulsion flow, reverse phase protein stone method, concussion shear method, spin. The coating method, as well as the assembly methods induced by thermal, magnetic and electric field forces, can be used to prepare colloidal photonic crystals. Although these methods can satisfy the assembly and application of the laboratory scale, we must develop a more efficient method to realize the large-scale preparation of photonic crystals. In the first work, we use seed growth two step method to synthesize highly monodisperse, evenly adjustable ZnO colloid particles and assemble ZnO colloid particles into ordered colloidal photonic crystal films by volatilization, concentration and spin coating in the first work. Under the condition of ensuring the uniformity and stability of the colloid, the synthetic system can be expanded to 1.5 mL, and the synthesized ZnO photonic crystal is thin with bright, saturated structure color and uniform and orderly internal structure. Compared with the disordered ZnO film, the ordered ZnO colloidal photonic crystal film has higher optical efficiency and superior photoelectric properties. The ordered, disordered ZnO colloidal photonic crystal film after calcination should be reduced to CO2 by photocatalytic reduction. We find that when the optical band is matched with the electron absorption band, the ZnO colloidal photonic crystal film has higher photocatalytic activity. In this work, we have found that the photocatalytic activity of the ZnO colloid photonic crystal film has higher photocatalytic activity. ZnO colloidal photonic crystal films with superior photocatalytic activity were synthesized by spin coating method, which realized the large-scale preparation of photocatalyst based on photonic crystal structure. It laid the foundation for the application of photonic crystal in the field of photocatalysis. In the second work, we synthesized the composite nanoparticles with superparamagnetic properties using LBL technology. Under the synergistic action of solvent volatilization and magnetic assembly, the colloidal photonic crystal film was prepared in scale. By electrostatic adsorption, we modified PEI and Fe_3O_4 on the surface of PS in turn, and then a layer of SiO_2. PS@PEI@Fe_3O_4@SiO_2 colloid particles were not only adjustable and narrow, but also can be used in one time. A good foundation is laid for subsequent assembly. The colloid particles of 280 nm to 450 nm can be obtained by adjusting the size of PS and the thickness of SiO_2. By using different sizes of colloid particles, we can assemble the photonic crystal with different saturation structure in the magnetic field. In addition, we pass the visible near infrared. The reflection spectrum shows the high uniformity of the photonic crystal film and the discovery of the film interference. Finally, we carry out continuous preparation of the photonic crystal film on the hydrophilic substrate by continuous injection of concentrated solution. Only 12 minutes can be used to obtain a long 100cm, wide 2cm photonic tape. The whole assembly process is not only green and green. It is fast, efficient and material saving, and is suitable for a variety of matrix materials in daily life. It provides a guarantee for the application of photonic crystal thin films.

【学位授予单位】：华东师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O648.1;O734
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本文编号：1818714