Preparating of Ultrafine Particles in Inorgaic Gel and Their Fixation

大多数功能材料都是由纳米颗粒组成的，只有当纳米颗粒分散良好时，纳米颗粒才具有优越的功能。然而，由于纳米粒子的凝聚倾向很强，人们一直在努力寻找纳米粒子的分散方法和分散状态的固定方法。在本项目中，胶体金作为纳米粒子，可以应用于催化、非线性光学器件和表面拉曼增强分析等功能材料。对金纳米粒子的分散和固定方法进行了研究，得出以下结论：1)采用材料的凝胶化现象作为固定方法，固定材料主要是合成粘土(白云母XLG)。金纳米粒子也在粘土悬浮液中形成，并固定在粘土凝胶中，保持分散状态。用干燥法制备了含有金层络合物的干膜，其结构可通过干式…进行控制方法2)用二氧化硅(表面负电荷)、氧化铝和二氧化钛(正电荷)溶胶研究了固定材料表面变化对金纳米粒子分散状态的影响。二氧化硅浓度不能控制胶体金的状态。另一方面，金离子以正电荷吸附在溶胶表面。当用于固定的溶胶浓度较低时，经常观察到纳米粒子呈三角形或六角形，然后很快凝聚。4)以PAANA聚合物的膨润土XLG粘土为固定材料，通过控制颗粒大小，可制得金纳米粒子，并在保持分散状态的情况下固定在材料中。3)在水溶性聚合物溶液中制备金纳米粒子，并与粘土凝胶进行比较。金离子只能吸附在阳离子聚电解质聚2-乙烯基吡啶(P2VP)上。尽管聚丙烯酸钠(PANA)是一种阴离子聚电解质，但阴离子胶体金在P2VP和聚丙烯酸钠(PANA)上都有吸附。聚合物的浓度和平均相对分子质量影响胶体金的颗粒大小和形成速率。较少

Most of functional materials consist of nanoparticles, which only have superior functions when nanoparticles disperse well. Due to the strong tendency of the coagulation of particles, however, there are many efforts to seek the dispersion methods of nanoparticles and the fixation methods of the dispersion state. In this projects, colloidal gold was used as nanoparticles, which could be applied to the functional materials, such as catalysis, non-linear optical device and substance for the surface Raman enhanced analysis. I investigated about the dispersion and fixation methods of gold nanoparticles, and then got following conclusion.1) The gelation phenomena of materials were used as the fixation method.The materials for fixation was mainly synthetic clay (Laponite XLG). Gold nanoparticles were also formed in the clay suspension, and fixed in the clay gel keeping the dispersion state. The dry membrane with gold-lay complex made by drying, and its structure could be controlled by the dry … More ing method.2) Effects of surface change of material for fixation on the dispersion state of gold nanoparticles were investigated by using silica (negative surface charge), and alumina and titania (positive surface charge) sol. The silica concentration could not control the state of colloidal gold. On the other hand, gold ion adsorbed on the surface of sol with positive charge. Nanoparticles were often observed to have triangle or hexagonal shape when the sol concentration for fixation was low, and then coagulated soon. The dispersion state was improved as the sol concentration for fixation increased.4) Gold nanoparticles can be prepared with the controlled particle size and fixed in materials as keeping the dispersion state, when Laponite XLG clay of PAANa polymer was used as the material for fixation.3) The gold nanoparticles were prepared in water-soluble polymer solution in comparison with clay gel. Gold ion was only adsorbed on poly 2-vinlpyridine (P2VP), which is a cationic polyelectrolyte. The anionic colloidal gold, however, was adsorbed on both P2VP and sodium polyacrylate (PAANa), although PAANa an anionic polyelectrolyte. The concentration and average molecular weight of polymer were found to affect the particle size and the formation rates of colloidal gold. Less