Here, we have demonstrated the production of colorless and full-color magnetic nanoparticles based on holmium (Ho)-doped polymers, which could not be achieved with conventional dark brown iron oxide magnetic nanoparticles. The coordination of Ho, a lanthanide with low colorability and a strong magnetic moment, with a poly(2-acetoacetoxy ethyl methacrylate) brush built on the surface of submicron-sized silica particles allowed for the formation of colorless magnetic nanoparticles. Additionally, bright and full-color magnetic nanoparticles were obtained by mixing different colored magnetic nanoparticles that were prepared by copolymerization of 2-acetoacetoxy ethyl methacrylate and dye monomers. Various colors, including transparency, were demonstrated by means of the present method, which determines the presence or absence of magnetism by Ho doping. The bright and magnetically controllable colored nanoparticles presented herein may have a significant impact on practical substances and applications, such as ink and biomedical and device applications.

中文翻译：

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基于Hol掺杂聚合物的全色磁性纳米粒子

在这里，我们已经证明了基于on（Ho）掺杂聚合物的无色全色磁性纳米颗粒的生产，这是常规的深棕色氧化铁磁性纳米颗粒无法实现的。Ho是一种低着色性和强磁矩的镧系元素，与亚微米级二氧化硅颗粒表面上的聚（2-乙酰乙酰氧基乙基甲基丙烯酸酯）刷配合使用，可以形成无色磁性纳米颗粒。另外，通过混合通过将甲基丙烯酸2-乙酰乙酰氧基乙酯和染料单体共聚而制备的不同的有色磁性纳米粒子，获得了明亮且全色的磁性纳米粒子。通过本方法证明了包括透明性在内的各种颜色，该方法通过Ho掺杂确定磁性的存在与否。