Liquid–liquid phase transfer of magnetite nanoparticles

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• 作者：Stefanie Machunsky ; Philipp Grimm ; Hans-Joachim Schmid ; Urs A. Peuker
• 关键词：Magnetite ; Fatty acid ; Nanoparticle ; Emulsion ; Phase transfer ; Interfacial transport
• 刊名：Colloids and Surfaces A: Physicochemical and Engineering Aspects
• 出版年：2009
• 出版时间：20 September 2009
• 年：2009
• 卷：348
• 期：1-3
• 页码：186-190
• 全文大小：444 K

文摘

The study presents first experimental results of the transfer of magnetite nanoparticles from an aqueous to a second non-miscible non-aqueous liquid phase. The transfer is based on the adsorption of macromolecular surfactants onto the particle surface at the liquid–liquid interface. For a successful direct phase transfer, it is essential to have cations, like ammonium ions, present in the aqueous phase as well as a threshold concentration of surfactant in the organic liquid phase. While penetrating the liquid–liquid interface, the particles are covered with the surfactant and therefore a partial de-agglomeration is initiated. Based on literature and experimental data a mechanism of surfactant adsorption is proposed. The competing adsorption of the surfactant molecules at the liquid–liquid interface leads to the formation of emulsions and therefore to a hindrance for particles passing the interface. Nevertheless a high efficiency of 100 % yield can be reached using optimized process parameters for the phase transfer process.