Univ Paris Diderot, Sorbonne Paris Cité, ITODYS, UMR 7086 CNRS, 15 rue J-A de Baïf, 75205 Paris Cedex 13, France.
J Colloid Interface Sci. 2013 Oct 1;407:210-4. doi: 10.1016/j.jcis.2013.06.002. Epub 2013 Jun 13.
The water stability of iron oxide nanoparticles (NPs) is a major issue for biomedical and biological applications. This paper presents a versatile approach for preparing water-soluble iron oxide nanoparticles coated by bifunctional oligo(ethylene oxide) (OEO) chains, carrying on the one side a diazonium end group for covalent grafting at the NP surface and on the other side an iniferter group (diethyl dithiocarbamate) for initiating the growing of poly(methacrylic acid). The nanoparticles were synthesized by coprecipitation in basic media and functionalized in situ by adding the diazonium salt directly in the synthesis medium. Oligo(ethylene oxide) with various chain lengths (from one to three monomer units) was grafted at the NP surface using this approach. The length of the OEO spacer between the NP surface and the iniferter end group was found to be a critical parameter for controlling the colloidal stability of the hybrid NPs. The polymerization time was also shown to strongly influence their colloidal stability, emphasizing the interest to control the interfacial properties of the hybrids for obtaining stable dispersions in water.
氧化铁纳米粒子（NPs）的水分散稳定性是生物医学和生物学应用中的一个主要问题。本文提出了一种通用的方法来制备由双功能聚氧乙烯（OEO）链包覆的水溶性氧化铁纳米粒子，这些链的一端带有重氮基团，可在 NP 表面进行共价接枝，另一端带有引发剂基团（二乙基二硫代氨基甲酸盐），用于引发聚（甲基丙烯酸）的生长。纳米粒子通过在碱性介质中共沉淀合成，并通过直接在合成介质中添加重氮盐原位进行功能化。使用这种方法，在 NP 表面接枝了具有不同链长（从一个到三个单体单元）的聚氧乙烯。发现 NP 表面和引发剂末端基团之间的 OEO 间隔物的长度是控制杂化 NPs 胶体稳定性的关键参数。聚合时间也被证明强烈影响它们的胶体稳定性，这强调了控制混合物的界面特性以获得在水中稳定分散体的重要性。
