Colloidal Cluster as, Model System for Ultrafine Particle

胶体簇作为超细颗粒模型系统

• 批准号: 11640588
• 负责人: YAMANAKA Junpei
• 金额: $ 2.18万
• 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: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2001
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11640588/
• 关键词: colloid; crystal; solid-liquid phase transition; ultrafine particle; gel; polyelectrolyte; cluster; confined space; 拘束空間; 相転移; 結晶化; 融点降下; サイズ効果; コロイド結晶; 固-液相転移

Dispersions of ionic polymer latex (diameter = 600nm) consisted of 10 to 1000 particles were confined in spherical voids having a diameter of several tens \am formed in a hydrogel (agarose) matrix. The system was constructed first by confining the latex dispersions in giant liposomes, immobilizing the liposomes by using the hydrogel matrix, and then removing the liposome membranes from the matrix. The latex particles inside the voids showed an extensive Brownian motion, and did not show aggregation even after one month. This system, as a whole, could be regarded as a model system of one superfine particle. The solid-liquid phase transition was examined both in bulk and the confined colloids, by applying confocal laser scanning microscopy and phase contrast microscopy. The salt concentration was 2μM, In bulk, the solid-liquid phase boundary laid at particle concentration = 1.0〜1.5 vol %. On the other hand, the confined dispersion took a liquid state even at 2.5 vol %. The present observation might correspond to a size effect for the melting point of a superfine particle system.

由10至1000个颗粒组成的离子聚合物胶乳（直径= 600 nm）的分散体被限制在形成于水凝胶（琼脂糖）基质中的直径为几十μ m的球形空隙中。该系统首先通过将胶乳分散体限制在巨大的脂质体中，通过使用水凝胶基质固定脂质体，然后从基质中除去脂质体膜来构建。空隙内的乳胶粒子表现出广泛的布朗运动，即使在一个月后也没有显示出聚集。该系统作为一个整体，可以看作是一个超细颗粒的模型系统。通过共聚焦激光扫描显微镜和相差显微镜研究了本体和受限胶体中的固-液相变。盐浓度为2μM。在本体中，固-液相边界位于颗粒浓度= 1.0 ~ 1.5体积%处。另一方面，即使在2.5体积%下，受限分散体也呈液态。目前的观察结果可能对应于超细颗粒系统熔点的尺寸效应。

项目成果

Junpei Yamanaka, Hiroyuki Hiroma, Masakatsu Yonese: "Colloidal dispersion confined in voids of polymer gel matrix"Proceedings of the Japan Academy SerB. Vol.77. 47-50 (2001)

Junpei Yamanaka、Hiroyuki Hiroma、Masakatsu Yonese：“胶体分散体限制在聚合物凝胶基质的空隙中”日本科学院院刊 SerB。