【作者】 鲁文胜；

【导师】 沈玉华； 谢安建；

【作者基本信息】 安徽大学 ， 高分子化学与物理， 2010， 博士

【摘要】 磁性纳米材料及其复合材料的制备是当今纳米新材料研究的一个重要领域。本论文首次利用生物分子葡萄糖为还原剂,通过绿色化学合成方法制备得到了超顺磁性四氧化三铁(Fe3O4)纳米颗粒；还利用原位还原法、共混包埋法、悬浮聚合法等方法分别制备得到了双功能Fe3O4/Se一维纳米板束、Fe3O4/Se/PANI复合材料、双醛淀粉包覆的和聚苯乙烯-丙烯酸包覆的Fe3O4磁性高分子微球。并对产物的组成、结构和性能进行了研究。具体研究内容如下：1.利用葡萄糖为还原剂,葡萄糖酸(葡萄糖的氧化产物)为稳定剂和分散剂,通过绿色化学合成方法制得了超顺磁性Fe3O4纳米颗粒。实验结果表明,制得的Fe3O4纳米颗粒为反尖晶石结构,平均粒径大小约为12.5 nm,粒径分布窄,分散性好,室温磁饱和强度达到60.5 emu/g,矫顽力和剩磁为零。这种制备方法非常简便,反应条件温和,可能为绿色合成其他纳米材料提供了一种简便的合适的途径。2.利用Fe3O4纳米颗粒能够吸附SeO32(Se(Ⅳ))离子,无需添加任何交联剂和分散剂,通过原位还原法制得均一的新颖的稻草捆样的具有荧光和超顺磁性双重性质的Fe3O4/Se一维纳米板束。结果表明,Fe3O4/Se一维纳米板的长、宽和厚度分别为6-8μm、300-400 nm和50 nm;Fe3O4纳米颗粒在制备双功能纳米复合物过程中可能起到“种子”和催化剂的双重作用；Fe3O4/Se纳米复合物中t-Se由于量子尺寸效应其禁带能隙和电子直接跃迁发生明显的蓝移；Fe3O4/Se一维纳米板束的形成机理可能涉及到Fe3O4/Se纳米球的形成、生长和聚集,以及一维纳米板的形成与自组装。我们所制得的稻草捆样的Fe3O4/Se纳米复合物还可能通过牺牲模板法制备其他具有特殊形貌的双功能纳米材料。例如：Fe3O4/Ag2Se, Fe3O4/Bi2Se3和Fe3O4/CdSe等。这种双功能材料在微电子和生物医学等领域具有潜在的应用价值。并在水热条件下利用SeO32-氧化苯胺,通过表面原位合成法制得兼具磁性和导电性能的纳米Fe3O4/Se/PANI复合材料。3.由于淀粉在三氯化铁酸性溶液中可以水解得到还原性糖(葡萄糖),在前面的研究基础上,我们又以淀粉和三氯化铁为原料,也成功地制备得到了超顺磁性Fe3O4纳米颗粒,并通过共混包埋法,以环氧氯丙烷为交联剂,将双醛淀粉包覆在Fe3O4磁性纳米颗粒上,制备出了磁性双醛淀粉复合纳米颗粒,并以牛血清白蛋白为模型对复合纳米颗粒固定蛋白能力进行了研究。磁性双醛淀粉复合纳米颗粒的粒径分布在50 nm-150 nm之间,平均粒径大小约为100 nm,醛基含量约为59.5%,双醛淀粉包裹率约为33.2%,室温饱和磁化强度为29.5 emu/g,没有剩磁和矫顽力,对蛋白的装载率和包封率分别为5.0%和54.4%。这也表明我们制备的产物在药物载体和靶向释药等方面具有潜在的应用。4.以苯乙烯为硬单体,丙烯酸为功能单体,利用分散聚合法,以油酸修饰的Fe3O4纳米颗粒为磁核,苯乙烯-丙烯酸共聚物为高分子壳层,制备得到了单分散、含有羧基的Fe3O4聚苯乙烯-丙烯酸[P(St-AA)]滋性高分子复合微球,并以姜黄素为模拟药物对磁性复合微球载药能力进行了研究。结果表明,我们制得的磁性高分子复合微球形貌为球形,粒径分布在50 nm-120 nm之间,平均粒径大小约为100 nm；磁性高分子复合微球中聚苯乙烯-丙烯酸的含量和Fe3O4磁性纳米微粒的含量分别约为74%和24.7%；对姜黄素的装载率和包封率分别为2.5%和44.4%；磁性高分子复合微球室温饱和磁化强度为20.2emu/g,没有剩磁和矫顽力。更多还原

【Abstract】 The synthesis of magnetic nanomaterials and magnetic nanocomposites is one of important fields in nano-material research. In the dissertation, we have first demonstrated a green synthetic approach for preparing superparamagnetic Fe3O4 nanoparticles usingα-D-glucose as a reducing agent. The other methods including in-situ reduction, co-embedding method, suspension polymerization etc., have been used to synthesize other nanocomposites such as bifunctional Fe3O4/Se one-dimensional (1D) nanoplank bundles, Fe3O4/Se/PANI nanocomposites, magnetic dialdehyde starch nanoparticles and Fe3O4/P(St-AA) magnetic polymer microspheres. The composition, construction and properties of the products have also been investigated.The main results can be summarized as follows:1. Superparamagnetic Fe3O4 nanoparticles were synthesized by green synthetic approach using a-D-glucose as a reducing agent and gluconic acid (the oxidative product of glucose) as stabilizer and dispersant without any additional stabilizer and dispersant. The results showed that the inverse spinel structure pure phase polycrystalline Fe3O4 was obtained, and the average size of Fe3O4 nanoparticles was about 12.5 nm, and the sample was similar to well dispersed Fe3O4 nanoparticles with narrow size distribution, and that the magnetic hysteresis loop at 300 K showed a saturation magnetization of 60.5 emu/g without coercivity and remanence. Because this method is very simple and easy under mild reaction condition, it might provide a new, mild, green, and economical route for the synthesis of other nanomaterials.2. Novel uniform straw-like Fe3O4/Se one-dimensional (1D) nanoplank bundles can be successfully prepared without any additional cross-linking agent and dispersant by in-situ reduction method since SeO32- (Se(Ⅳ)) anions could be adsorbed onto the surface of Fe3O4 nanoparticles. The width, thickness and length of as-prepared nanoplanks could be observed in the range of 300-400 nm,50 nm, and 6-8 μm, respectively. Fe3O4 nanoparticles might act as seeds and catalytic agent for the formation of the bifunctional nanocomposites. The products are of both fluorescent and superparamagnetic properties. More importantly, quantum size effect, which was reflected by marked blue shift of the band gap and direct transitions relative to the values of bulk t-Se, could be observed. The formation mechanism could be described as the linear aggregation and growth of Fe3O4/Se nanospheres, and the self-assembly of 1D Fe3O4/Se nanoplanks. The strawlike Fe3O4/Se could also be potentially converted to a series of bifunctional nanocomposites (e.g., Fe3O4/Ag2Se, Fe3O4/Bi2Se3, and Fe3O4/CdSe) with special morphology via the sacrificing template method. Moreover, the novel bifunctional nanocomposites would open up a potential application in microelectronics, biology, and medicine. Fe3O4/Se/PANI nanocomposites can also be obtained by in situ chemical oxidative polymerization in the presence of SeO32- anions.3. On the base of the previous study, superparamagnetic Fe3O4 nanoparticles were also obtained using hydrolysis product of starch i.e.α-D-glucose as the reducing agent, magnetic dialdehyde starch nanoparticles were successfully prepared with epichlorohydrin as crosslinker and dialdehyde starch (DAS) as wrapper by co-embedding method, and bovine serum albumin (BSA) as model drug was immobilized on the suface of magnetic dialdehyde starch nanoparticles. The particle size distribution of magnetic dialdehyde starch nanoparticles was 50-150 nm, and the average size was about 100 nm. The content of aldehyde group was 59.5%, and the package rate of DAS was 33.2%. The ratios of loading and coating of magnetic dialdehyde starch nanoparticles with BSA were 5.0% and 54.4%, respectively. The saturation magnetization of magnetic dialdehyde starch nanoparticles at 300 K was 29.5 emu/g without coercivity and remanence. The as-prepared products might have potential applications such as drug carrier and targeted drug release.4. Fe3O4/poly(styrene-co-acrylic acid) magnetic polymer microspheres were synthesized by suspension polymerization method using styrene as hard monomer, acrylic acid as functional monomer, Fe3O4 nanoparticles modified with oleic acid as magnetic nuclei,and poly(styrene-co-acrylic acid) [P(St-AA)] as shell. Drug-loading capacity of magnetic polymer microspheres with curcumin as model drug was also studied. The results indicated that magnetic polymer microspheres with monodisperse were obtained, the particle size distribution was 50-120 nm, and the average size was about 100 nm. The contents of P(St-AA) and Fe3O4 nanoparticles in magnetic polymer microspheres were 74% and 24.7%, respectively. The ratios of loading and coating of magnetic polymer microspheres with curcumin were 2.5% and 44.4%, respectively. The saturation magnetization of magnetic polymer microspheres at 300 K was 20.2 emu/g without coercivity and remanence.更多还原