This work aims to develop a multifunctional PMMA/CoFe₂O₄ polymeric film of low loss dielectric constant, high magnetic properties, and perceptible terahertz shielding effectiveness. Pure cobalt ferrite magnetic nanoparticles (CoFe₂O₄ MNPs) were prepared by a facile-modified solution deposition method. Then, the nanoparticles were loaded to poly (methyl methacrylate) of different ratios (x = 0, 5, 10, 15, and 20 wt%) to synthesize films by evaporative casting technique. X-ray diffraction (XRD) evidenced the formation of CoFe₂O₄ MNPs in the cubic spinal structure. The FTIR confirmed the interaction of CoFe₂O₄ MNPs with PMMA chains. Compared to the pure PMMA, the PMMA/CoFe₂O₄ nanocomposites were more thermally stable, as evidenced by thermogravimetric analysis, (TGA) and differential scanning calorimetry (DSC). The micrograph images by FESEM unraveled that CoFe₂O₄ MNPs have formed in different geometrical shapes (nanocubes, nanotubes, and nano oval). The values of the band gap energy were computed by the absorption spectra fitting (ASF) method. It varied from 4.94 to 4.68 eV, as the CoFe₂O₄ MNPs contents were changed from 0 to 20 wt%. Compared to host PMMA, the dielectric permittivity was enhanced, while the dielectric loss was slightly decreased. Therefore, the prepared film can be employed as a passive component in electronic circuits, namely capacitors and supercapacitors. The shielding effectiveness (SE) was found to be improved with frequency and CoFe₂O₄ content, reflecting the applicability of PMMA/CoFe₂O₄ MNPs films in terahertz shielding. The magnetic parameters were investigated by a vibrating sample magnetometer (VSM) and were found to increase with CoFe₂O₄ content, which could be used as a flexible film in magnetic applications.

中文翻译：

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用于磁性、电子和太赫兹屏蔽应用的轻质、自支撑 PMMA/CoFe2O4 聚合物薄膜的更绿色合成

这项工作旨在开发一种多功能的 PMMA/CoFe ₂ O ₄聚合物薄膜，它具有低损耗介电常数、高磁性和可感知的太赫兹屏蔽效能。纯钴铁氧体磁性纳米粒子 (CoFe ₂ O ₄ MNPs) 是通过简易改进的溶液沉积法制备的。然后，将纳米粒子负载到不同比例（x  = 0、5、10、15 和 20 wt%）的聚（甲基丙烯酸甲酯）中，通过蒸发浇铸技术合成薄膜。X 射线衍射 (XRD) 证明在立方脊柱结构中形成了 CoFe ₂ O _{4 MNP。FTIR 证实了 CoFe 2} O ₄的相互作用带有 PMMA 链的 MNP。与纯 PMMA 相比，PMMA/CoFe ₂ O ₄纳米复合材料的热稳定性更高，热重分析 (TGA) 和差示扫描量热法 (DSC) 证明了这一点。FESEM 的显微图像揭示了 CoFe ₂ O ₄ MNP 已形成不同的几何形状（纳米立方体、纳米管和纳米椭圆）。通过吸收光谱拟合 (ASF) 方法计算带隙能量的值。它在 4.94 到 4.68 eV 之间变化，因为 CoFe ₂ O ₄MNPs 含量从 0 到 20 wt%。与主体 PMMA 相比，介电常数有所提高，而介电损耗略有下降。因此，制备的薄膜可用作电子电路中的无源元件，即电容器和超级电容器。_{发现屏蔽效能 (SE) 随着频率和 CoFe 2} O ₄含量的增加而提高，反映了 PMMA/CoFe ₂ O ₄ MNPs 薄膜在太赫兹屏蔽中的适用性。通过振动样品磁强计 (VSM) 研究了磁性参数，发现其随着 CoFe ₂ O ₄含量的增加而增加，CoFe 2 O 4 可用作磁性应用中的柔性薄膜。