Department of Chemical System Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
J Am Chem Soc. 2009 Nov 18;131(45):16344-5. doi: 10.1021/ja907013u.
Colloidal silica spheres and their assembly processes are encountered in nature and numerous technological applications. We report here a novel and facile method to prepare highly anisotropic one-dimensional (1D) arrays of silica nanospheres (SNSs) in the liquid phase. Uniform-sized SNSs ca. 15 nm in size assemble into a 1D chain-like structure in the presence of a commercially available block copolymer. The 1D assembly in the liquid phase is evident from Cryo-TEM observations and time-dependent turbidity measurement of the suspension. The mode of the assembly has been systematically controlled by the concentration of the block copolymer, pH of the suspension, and the concentration of a salt added to the system. These results suggest the importance of the balance between electrostatic repulsion and block copolymer-mediated attractive interaction that are operative between particles in the formation of 1D array.
胶体二氧化硅球及其组装过程在自然界和众多技术应用中都有涉及。我们在此报告了一种新颖且简便的方法，可在液相中制备具有高各向异性的一维（1D）二氧化硅纳米球（SNS）阵列。在商业可得的嵌段共聚物的存在下，尺寸均匀的 SNS 约 15nm 大小会组装成 1D 链状结构。从低温透射电子显微镜观察和悬浮液的时变浊度测量中可以明显看出液相中的 1D 组装。通过改变嵌段共聚物的浓度、悬浮液的 pH 值以及向体系中添加盐的浓度，可以对组装方式进行系统控制。这些结果表明，在 1D 阵列的形成过程中，粒子间的静电排斥和嵌段共聚物介导的吸引力之间的平衡对于组装模式非常重要。
