MnZn铁氧体磁性纳米颗粒的合成、表征及磁热效应的研究

发布时间：2018-06-29 05:19

  本文选题：MnZn磁性纳米颗粒/微球 + 水热法　； 参考：《电子科技大学》2017年硕士论文

【摘要】：磁热疗是近几年发展起来的、研究最深入的一种治疗癌症的手段。各国学者对磁性纳米颗粒的制备、修饰及磁热疗中的应用投入了大量精力,并取得了显著进步。但低产热效率(SAR)或低升温能力仍是限制磁性纳米颗粒热疗临床开展的重要因素。另外,要求应用于热疗中的磁性纳米颗粒呈规则球形、分散性好。因此制备形貌规则、高分散、高饱和磁化强度(Ms)、高SAR的磁性纳米颗粒具有重大意义。首先,本文通过水热法合成MnZn磁性纳米颗粒,经XRD、SEM、VSM等测试方法表征,证实了合成的纳米颗粒纯度高、呈规则球形,Ms达36.3 emu/g。并探讨了反应时间、反应温度、PEG相对分子质量等对纳米颗粒性能的影响,优化水热制备MnZn磁性纳米颗粒工艺条件,为制备MnZn/Co Zn复合磁性纳米颗粒作好前期工作。最佳工艺条件为:12 h、180℃、0.5 g PEG6000。另外,磁性纳米颗粒不宜在空气中退火。但该法制备的MnZn磁性纳米颗粒的Ms、SAR不高。因此,接下来本论文采用以乙二醇(EG)为主的溶剂体系,溶剂热法合成了MnZn磁性纳米颗粒和磁性微球,其形貌规则,Ms高达80 emu/g,产热能力均优异。并分析了影响温升、SAR的因素。其中在EG:H2O=2:1体系中合成的MnZn磁性纳米颗粒(20 mg/m L、480 A)的SAR值最大,达119.7 W/g。并研究浓度、电流强度对该体系合成的纳米颗粒的温升、SAR值影响。结果表明,随着浓度增加,温升提高,而SAR值减小。温升、SAR值随着电流强度增大而单调增加。并发现最佳浓度为5 mg/m L,其SAR值最大,达224.84 W/g;同时得到低剂量(5 mg/mL)、低电流强度(380 A)仍具有高SAR值161.65 W/g,这更适宜于磁热疗临床的应用。对于不同种类、添加量表面修饰剂修饰的磁性微球的磁热效应研究表明:SAR值、温升随组成磁性微球的MnZn纳米晶粒的尺寸增大而增加,与微球直径无关。最后,水热法制备了MnZn/CoZn复合磁性纳米颗粒,其中MnZn/CoZn-PVP的SAR值达52.11 W/g,这提高了水热法合成的MnZn磁性纳米颗粒的SAR值;溶剂热法制备的Ag@MnZn复合纳米粒子、Ag@Mn Zn/R-GO复合材料都具有较高的SAR值。因为氧化石墨烯的加入,与Ag@MnZn复合纳米粒子相比,Ag@MnZn/R-GO复合材料无论是分散性、磁性能和产热能力都得到提高。另外,由于这两种复合材料还具有Ag的特性,因此我们推测它们除了作为磁热疗中的热介质,还在光热疗、荧光成像等领域存在潜在应用。
[Abstract]:Magnetic hyperthermia has been developed in recent years. Scholars all over the world have devoted a lot of attention to the preparation, modification and application of magnetic nanoparticles, and have made remarkable progress. However, low thermal efficiency (SAR) or low heating capacity are still the important factors limiting the clinical development of magnetic nanoparticles hyperthermia. In addition, the magnetic nanoparticles required to be used in hyperthermia are regular spherical and well dispersed. Therefore, it is of great significance to prepare magnetic nanoparticles with regular morphology, high dispersion, high saturation magnetization (Ms) and high SAR. Firstly, MnZn magnetic nanoparticles were synthesized by hydrothermal method and characterized by XRDX SEM- VSM. It was proved that the synthesized nanoparticles were of high purity, with regular spherical Ms up to 36.3 emu / g. The effects of reaction time, reaction temperature and relative molecular weight of PEG on the properties of nanocrystalline particles were discussed. The conditions of hydrothermal preparation of MnZn magnetic nanoparticles were optimized, and the preliminary work was made for the preparation of MnZn/ Co-Zn composite magnetic nanoparticles. The optimum technological conditions were as follows: 1: 12 h, 180 鈩，

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