Designing a large scale synthesis strategy for high quality magnetite nanocrystals on the basis of a solution behavior regulated formation mechanism
Designing a large scale synthesis strategy for high quality magnetite nanocrystals on the basis of a solution behavior regulated formation mechanism
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DOI：
10.1039/c6ce01963c
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发表时间：
2016-01-01
期刊：
影响因子：
3.1
通讯作者：
Tian, Qinghua
中科院分区：
文献类型：
--
作者：
Guo, Xueyi;Wang, Weijia;Tian, Qinghua
磁铁矿纳米晶体（MNCs）的大规模合成是满足生物医学应用（如磁共振成像（MRI）、磁热疗和靶向给药）对MNCs快速增长的需求的必要条件，但由于操作复杂、合成条件严格以及现有方法的误差容忍范围窄，实现其工业化生产仍很困难。本文以乙酰丙酮铁（Fe(acac) 3）、油酸（OA）和油胺（OAm）为反应体系，在溶液行为调控形成机理的指导下，设计了一种大规模的溶剂热合成方法。两种中间体Fe(acac)(x)(OA)(y)和N-（顺-9-十八烯基）-油酰胺（OOA）在调节MNCs的表面保护状态和反应体系的还原性方面起着关键作用。在不同的表面保护状态和还原性组合下，MNCs的最终尺寸从6.8 nm变化到37.4 nm， MNCs的形态从三角形棱柱形转变为球形（或准球形），这表明不同尺寸和形态的MNCs的形成是由于经历了不同的成核到生长的途径。此外，该反应系统对反应温度（220-240℃）和时间（2-6小时）不敏感，具有较好的操作误差容忍范围，适用于工业应用。据此，采用大规模合成方法合成高质量的MNCs，一次反应可制得直径为11.2 +/- 0.8 nm的球形单分散MNCs 6 g。
The large scale synthesis of magnetite nanocrystals (MNCs) is a sine qua non for supplying the rapidly increasing demand for MNCs in biomedical applications (e.g. magnetic resonance imaging (MRI), magnetic hyperthermia and targeted drug delivery), but it is still difficult to achieve their industrial production due to the operation complexity, strict synthetic conditions and the narrow error tolerance range of existing approaches. Here, we report a facile synthetic procedure using a solvothermal route with an iron acetylacetonate (Fe(acac) 3), oleic acid (OA) and oleylamine (OAm) reaction system on a large scale, which is designed under the guidance of the solution behavior regulated formation mechanism of MNCs. Two intermediates, Fe(acac)(x)(OA)(y) and N-(cis-9-octadecenyl)-oleamide (OOA), are found to play key roles in adjusting the surface protection status of MNCs and the reducibility of the reaction system. With diverse combinations of surface protection status and reducibility, the final size of MNCs changes from 6.8 nm to 37.4 nm, and the morphology of the MNCs transforms from triangular prismatic to spherical (or quasi spherical), which indicates that the formation of MNCs with distinct sizes and morphologies is attributed to experiencing different pathways from nucleation to growth. Moreover, the reaction system is insensitive to the reaction temperature (220-240 degrees C) and time (2-6 hours), exhibiting a preferable operation error tolerance range for industrial application. Accordingly, a large scale synthesis is applied for synthesizing high quality MNCs, and 6 grams of spherical and monodispersed MNCs with a diameter of 11.2 +/- 0.8 nm are obtained in a single reaction.