Studies on selective surface modification method and integration method for nanoparticles

纳米颗粒的单层覆盖可以极大地改变纳米颗粒的物理和化学性质，这是这些材料应用的关键因素。如果我们能够很容易地从纳米颗粒表面所需的区域去除定量有机化合物，然后在这些空白区域涂覆其他化合物而不使纳米颗粒变形，我们就可以通过使用改性颗粒构建特殊应用的目标结构。在本工作中，采用langmuir -类技术获得了半dodac覆盖的Au纳米粒子的二维组装，然后在Au粒子的另半表面覆盖HFOTAI。用改性后的颗粒制成各种溶剂的低聚物。低聚物形成的重要因素是纳米颗粒与溶剂之间的亲和力以及碳氢链和/或氟碳链之间的相互作用。此外，采用UV/臭氧处理覆盖dodac的金纳米颗粒，得到半覆盖dodac的金纳米颗粒。处理后的纳米粒子的和频产生谱表明，金纳米粒子表面的中心对称结构丧失，即保护表面活性剂分子的不对称分布。结果表明，有机化合物的分解是从纳米颗粒的上部开始的。此外，获得的半表面活性剂覆盖的金纳米颗粒被用作低聚物结构的构建块。当基片上的金纳米颗粒在甲苯中声纳时，得到了产率高达60%的低聚物。因此，发现在纳米颗粒表面引入两种被覆盖的有机化合物有助于制备纳米颗粒的低聚物结构。

Monolayer coverage of nanoparticles for appropriate functionalization, which can drastically change the physical and chemical properties of the nanoparticles, is a key factor in the application of these materials. If we are able to easily remove quantitative organic compounds from desired regions on a nanoparticles surface and then coat other compounds at these vacant regions without deformation of nanoparticles, we could construct target structures for special applications by the use of the modified particles. In the present work, 2D assembly of half DODAC-covered Au nanoparticles was obtained by the Langmuir-like technique, and then the other half-surface of Au particles was covered with HFOTAI. Oligomers were made into various solvents by using the modified particles. The important factor for oligomer formation was found to be the affinity between nanoparticles and solvents and the interaction between hydrocaobon chains and/or fluocarbon chains. Further, DODAC-covered Au nanoparticles were treated by UV/ozone to make half DODAC-covered particles. The sum frequency generation spectra of the treated nanoparticles indicated the loss of the centrosymmetric structure at the surface of Au nanoparticle, i.e., asymmetric distribution of protected surfactant molecule. This result shows that the decomposition of the organic compound starts from the upper part of the nanoparticles. Further, the half surfactant-covered Au nanoparticles obtained were employed as building blocks of oligomer structure. When the Au nanoparticles on a substrate were sonicated in toluene, oligomers were obtained in a high yield of 60%. Thus, it was found that the introduction of two covered-organic compounds to the nanoparticle surface is useful for fabricating the oligomer structures of nanoparticles.