In this study, magnetic iron oxide nanoparticles (Fe₃O₄) were produced by a green method, using aqueous extract of spent-tea waste as the reducing agent, which was subsequently used to prepare the magnetic and biodegradable Fe₃O₄/cellulose nanocomposite. The nanostructures were compared using advanced techniques such as UV–Vis spectrophotometry, Fourier transform infrared, X-ray spectroscopy, imaging by electron microscopy, thermal analysis, and vibrating-sample magnetometery. The data from the analyses showed that the synthesized nanocomposite had a spherical shape with an average particle size of 15.5 nm, which is smaller than the mean (28 nm) of the pure Fe₃O₄ nanoparticles. These results also showed that the prepared nanocomposite had a higher thermal resistance (450–800 °C) compared to pure cellulose. Another important feature of the nanoscale was the magnetic property (25 emu/g), which was smaller than that obtained in pure Fe₃O₄ nanoparticles (45 emu/g). In addition, the swelling capacity was studied as one of the functional capabilities of the nanocomposite, which was 139.3 g/g, more than the swell capacity obtained for pure cellulose (66.8 g/g). According to the results, the prepared Fe₃O₄/cellulose nanocomposite is suggested to be applied in metronidazole drug delivery system regarding its suitable and acceptable properties, such as high absorption capacity, controlled magnetic transferability and biodegradability as well as non-toxicity.

中文翻译：

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Fe 3 O 4纳米粒子的绿色合成及其在制备Fe 3 O 4 /纤维素磁性纳米复合材料中的应用：药物递送系统的合适建议

在这项研究中，以废茶水提取物为还原剂，通过绿色方法制备了磁性氧化铁纳米粒子（Fe ₃ O ₄），随后将其用于制备磁性可生物降解的Fe ₃ O ₄ /纤维素。纳米复合材料。使用诸如紫外可见分光光度法，傅立叶变换红外，X射线光谱，电子显微镜成像，热分析和振动样品磁强计等先进技术对纳米结构进行了比较。分析数据表明，合成的纳米复合材料呈球形，平均粒径为15.5 nm，小于纯Fe ₃ O ₄的平均值（28 nm）。纳米粒子。这些结果还表明，与纯纤维素相比，制备的纳米复合材料具有更高的耐热性（450-800°C）。纳米级的另一个重要特征是磁性（25 emu / g），比纯Fe ₃ O ₄纳米颗粒（45 emu / g）小。此外，溶胀能力被研究为纳米复合材料的功能能力之一，为139.3 g / g，比纯纤维素的溶胀能力（66.8 g / g）高。根据结果​​，制备了Fe ₃ O ₄由于其合适和可接受的性质，例如高吸收能力，受控的磁性转移性和生物降解性以及无毒性，建议将α-纤维素纳米复合材料应用于甲硝唑药物递送系统。