Fabrication of centimeter-sized colloidal crystals using pH gradient and gelled crystal template

使用 pH 梯度和凝胶晶体模板制备厘米大小的胶体晶体

• 批准号: 14540538
• 负责人: YAMANAKA Junpei
• 金额: $ 2.3万
• 依托单位: Nagoya City University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2002
• 资助国家: 日本
• 起止时间: 2002 至 2003
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-14540538/
• 关键词: colloid; crystal; solid-liquid phase transition; one-directional growth; pH gradient; silica particle; rection-diffuion process; photonic crystal

Aqueous dispersions of charged colloidal silica particles showed a novel one-directional crystal growth, when pyridine, a weak base, was diffused from one end of the dispersions. The colloidal crystal consisted of pillar-shaped crystal grains whose height and width were in the order of cm and sub-cm, respectively. By numerical analysis of the growth curves based on the reaction-diffusion equation, the growth process was explainable in terms of i)the diffusion of pyridine with neutralization reactions between weakly acidic silica surfaces, ii)charging up of the silica particles and iii)the charge-induced crystallization of the dispersions. The presence of freely diffusing species, which extended the highly charged region forward, was essentially important for the one-directional growth. A similar one-directional crystal growth was observed when NaHCO_3, a salt of a weak acid and strong base, was used, but the growth was hardly observed by using a strong base NaOH.

当弱碱吡啶从分散液的一端扩散时，带电胶体二氧化硅颗粒的水分散液表现出一种新颖的单向晶体生长。胶体晶体由柱状晶粒组成，其高度和宽度分别为cm和亚cm量级。基于反应-扩散方程的生长曲线的数值分析，生长过程可以解释为i）吡啶的扩散与弱酸性二氧化硅表面之间的中和反应，ii）二氧化硅颗粒的充电和iii）分散体的电荷诱导结晶。自由扩散的物种的存在，这扩展了高电荷区向前，是非常重要的单向增长。当使用弱酸和强碱的盐NaHCO_3时，观察到类似的单向晶体生长，而使用强碱NaOH时几乎观察不到晶体生长。

项目成果

Junpei Yamanaka, Masako Murai, Yumie Iwayama, Masakatsu Yonese, Kensaku Ito, Tsutomu Sawada: "One-directional crystal growth in charged colloidal silica dispersion driven by diffusion of base"Journal of the American Chemical Society. (in press). (2004)

Junpei Yamanaka、Masako Murai、Yumie Iwayama、Masakatsu Yonese、Kensaku Ito、Tsutomu Sawada：“由碱扩散驱动的带电胶体二氧化硅分散体中的单向晶体生长”美国化学会杂志。

山中淳平, 岩山由美江, 村井雅子, 米勢政勝: "塩基の拡散による荷電コロイド結晶の一方向成長"高分子加工. (印刷中). (2004)

Junpei Yamanaka、Yumie Iwayama、Masako Murai、Masakatsu Yonese：“通过碱扩散实现带电胶体晶体的单向生长”聚合物加工（2004 年出版）。

Junpei Yamanaka, Yumi Iwayama, Masako Murai, Masakatsu Yonese: "One-directional crystal growth in charged colloid by diffusion of base (in Japanese)"Kobunshi Kako. (in press). (2004)

Junpei Yamanaka、Yumi Iwayama、Masako Murai、Masakatsu Yonese：“通过碱扩散实现带电胶体中的单向晶体生长（日语）”Kobunshi Kako。

J.Yamanaka, M.Murai, Y.Iwayama, M.Yonese, K.Ito, T.Sawada: "One-directional crystal growth in charged colloidal silica dispersion driven by diffusion of base"Journal of the American Chemical Society. (印刷中). (2004)

J.Yamanaka、M.Murai、Y.Iwayama、M.Yonese、K.Ito、T.Sawada：“由碱扩散驱动的带电胶体二氧化硅分散体中的单向晶体生长”美国化学会杂志（2004 年）。 ）

山中淳平, 村井雅子, 岩山由美江, 米勢政勝: "塩基の拡散による荷電コロイド結晶の一方向成長"高分子加工. (印刷中). (2004)

Junpei Yamanaka、Masako Murai、Yumie Iwayama、Masakatsu Yonese：“通过碱扩散实现带电胶体晶体的单向生长”聚合物加工（2004 年出版）。