超顺磁性的Fe3O4@mSiO2纳米粒子的制备
本文使用热溶剂法制备得到分散性良好、磁性强度高、尺寸均一的Fe3O4纳米粒子；通过采用改进的Stöber法制备出具有超顺磁性核壳结构的Fe3O4@SiO2纳米粒子，研究了正硅酸乙酯的用量与Fe3O4@SiO2粒子尺寸关系。21531
透射电镜和扫描电镜表征可得，通过实验可成功制备得到粒径约在200nm左右，尺寸可调可控的Fe3O4@SiO2纳米粒子，振动样品磁强计测试表现出超顺磁性。
毕业论文关键词： 纳米粒子；超顺磁性；核-壳；二氧化硅；四氧化三铁
Preparation of superparamagnetic Fe3O4@mSiO2 nanoparticle
Abstract: In recent years, with the prosperous development of nanomaterial interdis- ciplinary science, magnetic nanoparticle have been widely applied in metal ions detection and removal, cell separation, intellective drug delivery, bio-imaging and targeting therapy. Fe3O4@SiO2 nanoparticle gained much attention as a magnetically separable carrier, which has the features of biocompatibility, renewability andstability.
In this dissert, Fe3O4 particulates with well monodisperse, uniform morphology and high magnetic saturation have been synthesized by solvothermal method．The superparamagnetism microspheres with core-shell structure (Fe3O4@SiO2) have been prepared through a modified Stöber method. It is showed that concentration of TEOS would affect the sizes and the morphologies of the particles.
The obtained nanoparticle was characterized by transmissionelectron microscopy (TEM) and Scanning electron microscopy (SEM). The results show that the process of co-precipitation can obtain stable and well-disperse Fe3O4@SiO2 particle which size is about 200nm. Both of samples had superparamagnetis which is indicated by hysteresis curve.
Key words: Nanoparticle, Superparamagnetism, Core/Shell, Silicon dioxide, Ferroferric oxide
目 录
第一章 绪论 1
1.1 引言 1
1.2 纳米材料 1
1.2.1 纳米材料的特性 2
1.2.1.1 小尺寸效应 2
1.2.1.2 量子尺寸效应 2
1.2.1.3 表面效应 2
1.2.1.4 宏观量子隧道效应 2
1.3 磁性纳米材料 3
1.3.1 磁性纳米颗粒的基本性质 3
1.3.1.1磁畴 3
1.3.1.2 矫顽力 4
1.3.1.3 居里温度 4
1.3.1.4 超顺磁性 4
1.3.2 磁性纳米粒子-超顺磁性纳米粒子 5
1.3.3 磁性纳米材料的制备方法 6
1.3.3.1 化学共沉淀法 6
1.3.3.2 水热合成法 7
1.3.3.3 溶剂热合成法 7
1.4 磁性纳米粒子的表面修饰保护 8
1.4.1 有机材料 8
1.4.2 无机材料 8
1.4.2.1 二氧化硅 8
1.5 超顺磁性的Fe3O4@mSiO2纳米粒子的形成原理 9
1.6 磁性二氧化硅微球及复合粒子的制备 10
1.6.1 溶胶-凝胶法-Stöber法 10
1.6.2 微乳液法 10
1.7 超顺磁性纳米材料的表征 11
1.7.1 透射电子显微镜 11
1.7.2 扫描电子显微镜 11
1.7.3 X-射线衍射仪 12