Formation of regular colloidal clusters using charged colloidal crystallization on curved surfaces

2014 Fiscal Year Final Research Report

• Project/Area Number: 24550160
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Functional materials chemistry
• Research Institution: Nagoya City University
• Principal Investigator: YAMANAKA Junpei 名古屋市立大学, 薬学研究科(研究院), 教授 (80220424)
• Co-Investigator(Kenkyū-buntansha): OKUZONO Tohru 名古屋市立大学, 大学院薬学研究科, 准教授 (10314725) ; TOYOTAMA Akiko 名古屋市立大学, 大学院薬学研究科, 講師 (50453072)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: コロイド / 微粒子 / クラスター / クーロン引力 / 界面活性剤 / 凝集 / 会合体 / 正多面体

Outline of Final Research Achievements

We examined clustering of oppositely charged binary colloidal particles. Optimum conditions were examined for the formations of tetrahedral clusters (particle size ratio, concentration ratio, charge number, etc). We also found that clustering of polystyrene (PS) and silica particles, both of which were negatively charged, could be controlled by additions of cationic surfactant cetylpyridinium chloride (CPC); Because of the absorption of the CPC molecules, the charge number of the PS and silica particles decreased with increasing CPC concentration (Csurf) and inverted to be positive after passing through the isoelectric point (Csurf = Ciep). The hydrophobic PS particles had much lower Ciep than that of hydrophilic silica particles. When Csurf was in the region between their Ciep’s, the PS and silica particles were charged oppositely, resulted in the clustering. Constructions of higher organizations of clusters are in progress.

Free Research Field

コロイド科学、物理化学