Surface Functionalization of Magnetic Nanoparticles Using a Thiol-Based Grafting-Through Approach
Surface Functionalization of Magnetic Nanoparticles Using a Thiol-Based Grafting-Through Approach
复制标题
基于巯基的磁性纳米粒子表面功能化
DOI：
10.3390/surfaces3010011
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发表时间：
2020-03-01
期刊：
影响因子：
2
通讯作者：
Schacher, Felix H.
中科院分区：
文献类型：
--
作者：
Biehl, Philip;Schacher, Felix H.
在这里，我们描述了通过使用表面结合的硫醇基团作为自由基聚合过程中的转移剂来简单直接地合成不同的多功能磁性纳米颗粒。该改性包括用（3-巯基丙基）三甲氧基硅烷进行表面硅烷化的第一步，以获得硫醇改性的纳米颗粒，该纳米颗粒进一步用作多种聚合物改性的平台。硅烷化在壳厚度和粒径分布方面进行了优化，并通过动态光散射（DLS）、热重分析（TGA）、透射电子显微镜（TEM）和能量色散X射线光谱（EDX）对所得材料进行了研究。随后，在硫醇修饰的纳米粒子存在下检查了不同单体（丙烯酸叔丁酯（tBA）、甲基丙烯酸甲酯（MMA）、苯乙烯、2-乙烯基吡啶（2VP）和N-异丙基丙烯酰胺（NIPAAm））的自由基聚合。在此过程中，形成了共价锚定的聚合物壳，并对所得核壳杂化材料的尺寸（DLS、TEM）、壳厚度（TGA、TEM）和官能团的存在（衰减全反射傅立叶变换红外光谱（ATR-FT-IR））进行了分析。因此，壳导致颗粒的不同溶液行为，并且在某些情况下导致对酸的稳定性增加。此外，我们研究了聚合过程中纳米颗粒浓度的影响，发现对所得聚合物的分散性有显着影响。最后，我们比较了表面结合聚合物和聚苯乙烯溶液中形成的聚合物的特性。本文提出的方法提供了对各种核-壳纳米复合材料的直接访问。
Here we describe a simple and straightforward synthesis of different multifunctional magnetic nanoparticles by using surface bound thiol-groups as transfer agents in a free radical polymerization process. The modification includes a first step of surface silanization with (3-mercaptopropyl)trimethoxysilane to obtain thiol-modified nanoparticles, which are further used as a platform for modification with a broad variety of polymers. The silanization was optimized in terms of shell thickness and particle size distribution, and the obtained materials were investigated by dynamic light scattering (DLS), thermogravimetric analysis (TGA), transmission electron microscopy (TEM), and energy-dispersive X-ray spectroscopy (EDX). Subsequently, the free radical polymerization of different monomers (tert-butyl acrylate (tBA), methyl methacrylate (MMA), styrene, 2-vinyl pyridine (2VP), and N-isopropylacrylamide (NIPAAm)) was examined in the presence of the thiol-modified nanoparticles. During the process, a covalently anchored polymeric shell was formed and the resulting core-shell hybrid materials were analyzed in terms of size (DLS, TEM), shell thickness (TGA, TEM), and the presence of functional groups (attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FT-IR)). Hereby, the shell leads to a different solution behavior of the particles and in some cases an increased stability towards acids. Moreover, we examined the influence of the nanoparticle concentration during polymerization and we found a significant influence on dispersity of the resulting polymers. Finally, we compared the characteristics of the surface bound polymer and polymer formed in solution for the case of polystyrene. The herein presented approach provides straightforward access to a wide range of core-shell nanocomposites.