Organic-dye-coupted magnetic nanoparticles encaged inside thermoresponsive PNIPAM microcapsutes
Organic-dye-coupted magnetic nanoparticles encaged inside thermoresponsive PNIPAM microcapsutes
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DOI：
10.1002/smll.200400145
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发表时间：
2005-07-01
期刊：
影响因子：
13.3
通讯作者：
Fu, SK
中科院分区：
文献类型：
--
作者：
Guo, J;Yang, WL;Fu, SK
我们提出了一种新的方法，用于制造温度响应性聚合物微胶囊与移动的磁性核心，在改变温度时进行体积相变，并在外部磁场下收集。我们制备了具有明确核壳结构的有机/无机复合微球，该微球由交联聚（N-异丙基丙烯酰胺）（PNIPAM）壳和中心由磁铁矿纳米颗粒点缀的二氧化硅核组成。由于模板分解产物的渗透依赖于由外部温度变化触发的PNIPAM壳的渗透性，因此通过用NaOH水溶液处理，定量地去除夹在磁芯和PNIPAM壳之间的二氧化硅层以生成具有移动的磁芯的PNIPAM微胶囊。为了开发所需的多功能微胶囊，未蚀刻的二氧化硅表面内部的改性可以通过用硅烷偶联剂处理来实现，所述硅烷偶联剂含有可以容易地与催化剂、酶或标记分子结合的官能团。在此，异硫氰酸荧光素（FITC），其是一种常见的有机染料，被连接到移动的磁芯的内部，以得到具有FITC标记的磁芯的PNIPAM微胶囊。在该系统中，可以预期智能聚合物微胶囊的腔性质的功能化的延伸是将其他靶分子吸附到移动的核上，以便在中空笼中引入其他期望的功能。
We present a new approach for the fabrication of thermoresponsive polymer microcapsules with mobile magnetic cores that undergo a volume phase-transition upon changing the temperature and are collected under an external magnetic field. We have prepared organic/inorganic composite microspheres with a well-defined core-shell structure that are composed of a crosslinked poly (N-isopropylacrylamide) (PNIPAM) shell and silica cores dotted centrally by magnetite nanoparticles. Since the infiltration of template-decomposed products is dependent on the permeability of PNIPAM shells triggered by changes of exterior temperature, the silica layer sandwiched between the magnetic core and the PNIPAM shell was quantitatively removed to generate PNIPAM microcapsules with mobile magnetic cores by treatment with aqueous NaOH solution. For development of the desired multifunctional microcapsules, modification of the unetched silica surface interiors can be realized by treatment with a silane coupling agent containing functional groups that can easily bind to catalysts, enzymes, or labeling molecules. Herein, fluorescein isothiocyanate (FITC), which is a common organic dye, is attached to the insides of the mobile magnetic cores to give PNIPAM microcapsules with FITC-labeled magnetic cores. In this system, it can be expected that an extension of the functionalization of the cavity properties of smart polymer microcapsules is to immobilize other target molecules onto the mobile cores in order to introduce other desired functions in the hollow cage.