Formation of magnetically anisotropic composite films at low magnetic fields
Formation of magnetically anisotropic composite films at low magnetic fields
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低磁场下磁各向异性复合薄膜的形成
DOI：
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发表时间：
2017
期刊：
影响因子：
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通讯作者：
D. Fragouli
中科院分区：
文献类型：
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作者：
M. Zahedi;I. Ennen;S. Marchi;Markus J. Barthel;A. Hütten;A. Athanassiou;D. Fragouli
我们提出了一个简单的两步技术，用于制造聚（甲基丙烯酸甲酯）复合材料与嵌入对齐的磁链。首先，在聚（甲基丙烯酸甲酯）溶液中实现铁磁微丝组装铁纳米粒子在甲基丙烯酸甲酯溶液中在160 mT的外部磁场下加热。单体在整个线中的同时热聚合是其永久连接和稳定性的原因。接下来，在低磁场（20-40 mT）存在下将含有随机分散的微丝的聚合物溶液浇铸在固体基底上，所述低磁场在溶剂蒸发时诱导微丝最终排列成长磁链。我们证明，组装在微丝的形式的纳米粒子的存在下是在低磁场下的各向异性膜的形成的一个关键因素。事实上，这种低场不能驱动和组装相同类型的聚合物溶液中分散的磁性纳米颗粒。因此，这种创新的方法可用于在低磁场下合成磁各向异性纳米复合膜。
We present a straightforward two-step technique for the fabrication of poly (methyl methacrylate) composites with embedded aligned magnetic chains. First, ferromagnetic microwires are realized in a poly (methyl methacrylate) solution by assembling iron nanoparticles in a methyl methacrylate solution under heat in an external magnetic field of 160 mT. The simultaneous thermal polymerization of the monomer throughout the wires is responsible for their permanent linkage and stability. Next, the polymer solution containing the randomly dispersed microwires is casted on a solid substrate in the presence of a low magnetic field (20–40 mT) which induces the final alignment of the microwires into long magnetic chains upon evaporation of the solvent. We prove that the presence of the nanoparticles assembled in the form of microwires is a key factor for the formation of the anisotropic films under low magnetic fields. In fact, such low fields are not capable of driving and assembling dispersed magnetic nanoparticles in the same type of polymer solutions. Hence, this innovative approach can be utilized for the synthesis of magnetically anisotropic nanocomposite films at low magnetic fields.