【作者】 楚会娟；

【导师】 戴金辉；

【作者基本信息】 中国海洋大学 ， 材料学， 2010， 硕士

【摘要】 本文采用种子乳液聚合法和无皂乳液聚合法制备不同粒径的单分散PS胶体球,通过浸渍-提拉法组装了PS胶体晶体阵列,并以此为模板制备了SiO2和TiO2纳米结构。分析了单分散PS球和胶体晶体的合成机理,讨论了采用浸渍-提拉法组装胶晶模板的特点,研究了工艺参数对PS球的合成、模板组装质量和有序纳米结构形貌的影响,对PS胶晶模板和模板结构进行了分析与表征。以苯乙烯为单体,过硫酸钾为引发剂,十二烷基硫酸钠为乳化剂进行了种子乳液聚合。研究了影响因素对制得的PS胶体球的粒径及粒径分布的影响,结果如下：在其他条件不变的情况下,胶体球粒径随苯乙烯单体增加而增加；引发剂增加,胶体球粒径成增大趋势；随乳化剂的增加,胶体球粒径减小。以苯乙烯为单体,过硫酸钾为引发剂进行了无皂乳液聚合。研究了单体、引发剂及反应时间等因素对合成的PS胶体球的粒径及其分散性的影响,结果如下：在其他条件不变的情况下,胶体球粒径随单体浓度的增加而增大；引发剂增加,胶体球粒径呈减小趋势；反应时间增加,胶体球粒径增大。PS胶体球在固-液界面的弯月面处进行组装的过程中,吸附力、浮力和毛细管力使胶体球成核并生长成为密排的胶体晶体。由于弯月区上沿的生长边的快速移动,浸渍-提拉法增大了湿阵列的面积,使溶剂蒸发和乳液流动得到了增强。合适的提拉速率能够得到密排的高度有序的胶晶模板。基板的物理化学性质对模板形貌也有影响,基底表面要洁净、平坦(起伏应比颗粒直径小得多),表面化学性质均一,有良好的亲水性。胶体球粒径均一、分布窄且分散良好,有利于形成完美的PS胶晶模板。采用浸渍法在PS胶晶模板的间隙内填充溶胶时,由于毛细管力的作用,易于实现前驱体溶胶的有效填充。溶胶浓度和溶胶颗粒粒径是影响纳米结构的重要因素。溶胶浓度的选择应与模板球径协同考虑,以得到规则排列的纳米结构。PS球直径和溶胶浓度都会影响纳米结构的形貌。填充硅溶胶和二氧化钛溶胶的PS胶晶阵列模板经过干燥后,除去PS胶体球得到了连续的规则的纳米结构,通过扫描电子显微镜对纳米结构进行了表征。更多还原

【Abstract】 The mono-disperse Polystyrene (PS) colloid spheres with controllable size were synthesized by the seeded emulsion polymerization and Emulsifier-free emulsion polymerization. Polystyrene (PS) colloid spheres crystal array was assembled by dip-drawing method and ordered SiO2, TiO2 nano-structure were fabricated by using the PS colloid crystal as template. The forming mechanism of colloid spheres and colloid crystal were discussed, the advantage of dip-drawing method to assemble PS template was exhibited, the influence of fabricating parameters on the preparation of spheres, array quality and morphology of nano-structure was studied; and the structure of PS array,SiO2 and TiO2 were analyzed.The seeded emulsion polymerization was prepared by using styrene as monomers, KPS as initiator, SDS as emulsifier. The influence factors on PS colloid sphere diameter have been investigated. The results revealed:When other factors were kept constant, the diameter of PS colloid spheres increased with monomer concentration. When the initiator reagent increased, the diameter of PS colloid spheres increased; When the concentration of emulsifier increased, the diameter of PS colloid spheres decreased.The Emulsifier-free emulsion polymerization was prepared by using styrene as monomers, KPS as initiator. The influence factors of monomer, initiator and polymerize time on PS colloid sphere diameter have been investigated:When other factors were kept constant, the diameter of PS colloid spheres increased with monomer concentration. When the initiator reagent increased, the diameter of PS colloid spheres decreased; When the polymerize time increased, the diameter of PS colloid spheres increased.In the course of PS sphere assembly in meniscus at the solid/liquid interface, the absorption force, flotage and capillary force are responsible to the nucleation and growth of colloid crystal. Dip-drawing method enlarges the evaporation area of the wet array due to the quicker movement of leading edge, so that the solvent evaporation and solution flux are accelerated.Appropriate drawing rate can obtain highly ordered colloid crystal templet. The properties of base plate have effect on morphology of colloid crystal templet, the base plates should be clean and enev. To obtain a perfect colloid crystal, the sphere diameter should be homogeneous.With dipping method used to fill sol into the PS array can lead to a stable filling content by capillary force. The concentration of sol and sol particle diameter are important factors on effecting nano-structure. The choice of the sol concentration used should match to the sphere size to obtain ordered nano-structure, because the appearance of nano-structure is affected by both PS sphere diameter and sol concentration.The nano-structure was obtained after dryness and removing PS template, then it is characterized by SEM.更多还原