单分散Fe3O4@SiO2/Au复合纳米颗粒的制备

制备了尺寸为30nm,具有磁响应的单分散Fe3O4@SiO2/Au核壳纳米颗粒,并研究其光学性质。首先利用热分解法制备油酸修饰的Fe3O4纳米粒子,再用反相微乳法制备Fe3O4@SiO2纳米粒子,最后利用表面修饰的氨基还原性,获得Fe3O4@SiO2/Au核壳复合纳米颗粒。分别用TEM、XRD、Zeta电位与粒度分析仪对产物形貌、结构、表面电位和粒径分布进行表征,用紫外-可见分光光度计对光学性质进行了测试。     

P(AA-co-MPC)修饰超顺磁性Fe3O4纳米粒子的制备与表征

以丙烯酸(AA)和2-甲基丙烯酰氧乙基磷酰胆碱(MPC)为单体,采用RAFT聚合合成系列共聚物(P(AA-co-MPC)),并通过化学共沉淀法制备P(AA-co-MPC)表面修饰的磁性Fe3O4纳米粒子。利用1H NMR,FTIR,GPC,TG,TEM,XRD,Zeta电位及粒度分析仪和Squid-VSM磁性测量系统等手段对共聚物和纳米粒子进行表征。结果表明:采用RAFT聚合成功合成了窄分子量分布的P(AA-co-MPC),磁性Fe3O4纳米粒子表面含有修饰基团;单体摩尔比(AA∶MPC)为1∶1时合成的共聚物修饰磁性Fe3O4纳米粒子的分散性最好,具有最小的水合粒径(36.54±4.00)nm和最窄的粒径分布,最高的Zeta电位(-30.98±1.25)mV,饱和磁化强度为65.57A·m^2·kg^-1,剩磁和矫顽力均为零,具有超顺磁性。     

多聚磷酸钠改性水基Fe_3O_4磁流体的制备与表征

采用多聚磷酸钠(STPP)对Fe3O4磁性纳米粒子进行表面改性,制备稳定的水基磁流体。通过傅里叶变换红外光谱(FTIR)、热重分析(TG)、透射电镜(TEM)、X射线衍射(XRD)、X射线光电子能谱(XPS)、振动样品磁强计(VSM)及Zeta电位仪对所制备的磁流体进行表征。结果表明,STPP包覆于Fe3O4磁性纳米粒子的表面,当pH>3时,粒子表面带有负电荷;磁性测试结果表明,STPP/Fe3O4磁性纳米粒子具有超顺磁性,其饱和磁化强度为62.3 A.m2.kg-1。     

两水亲性嵌段共聚物修饰Fe3O4磁纳米粒子的合成及表征

本文通过共沉淀法,合成了两水亲性嵌段共聚物聚(乙烯吡咯烷酮)-b-聚(苯乙烯-alt-马来酸酐)(PVP-b-PSMA)修饰的Fe3O4磁纳米粒子。并利用动态光散射法(DLS)、X射线粉末衍射(XRD)和扫描电镜(SEM)对磁纳米粒子进行表征。结果表明,嵌段共聚物修饰的Fe3O4磁纳米粒子与纯Fe3O4磁纳米粒子比较,分布更分散,为大小均匀的球状颗粒,其粒径在100nm左右。振动样品磁强计(VSM)测试结果显示,在室温、外加磁场下,该磁纳米粒子呈现超顺磁性,其饱和磁化强度为55emuΠg。以上结果表明Fe3O4磁纳米粒子有望应用于磁靶向药物控释、热疗、酶的固定、生物分离等生物医学领域。     

表面活性剂对磁流体稳定性及外层包覆结构的影响

采用化学共沉淀法制备粒径分布均匀的纳米Fe3O4颗粒,用油酸钠和聚乙二醇4000(PEG4000)对纳米Fe3O4颗粒进行表面修饰,制得分散稳定的纳米Fe3O4磁流体,通过电动电位(Zeta电位)、粒径测试、离心沉淀、红外光谱分析(FT-IR)和热分析(TG)对修饰后的纳米Fe3O4颗粒进行了稳定性能评价与结构表征。结果表明,油酸钠与纳米Fe3O4颗粒存在两种不同类型的化学键作用;增大油酸钠加入量不会改变Fe3O4颗粒表面包覆结构,但是,其在纳米Fe3O4颗粒表面的吸附量呈先增加后降低的趋势;PEG4000物理吸附于油酸钠包覆的纳米Fe3O4颗粒表面,PEG4000的加入会进一步提高磁流体的稳定性。     

聚砜-Fe3O4磁性复合超滤膜截留分子量随磁场的变化规律

在制备聚砜-Fe3O4磁性复合超滤膜的过程中,为避免纳米Fe3O4粒子团聚,采用偶联剂包裹共沉淀法得到Fe3O4粒子,然后采用相转化法制备了聚砜-Fe3O4磁性复合超滤膜。Zeta电位仪检测出纳米粒子平均粒径为66.83 nm,红外分析发现偶联剂结合在粒子表面。经扫描电镜观察和孔径分布分析得出复合膜中纳米Fe3O4粒子分布均匀,无团聚现象出现,孔径分布较窄。聚乙二醇系列测定基膜为2万的复合膜截留分子量从0T下的19800减小至0.4T的15000,继续增大外加磁场,截留分子量基本不再变化。     

双微乳液法制备纳米磁性Fe3O4粉体的研究

现代诊断学的发展使得纳米级超顺磁性的Fe3O4粒子在医学领域具有重要应用价值.本实验采用双微乳液法制备纳米磁性Fe3O4粉体.从反应物浓度、表面活性剂用量、油相用量及反应温度等方面讨论对产物粒径的影响,通过正交试验确定了制备纳米Fe3O4粉体的最佳工艺条件.对获得的粉体采用激光散射法粒度测试、XRD物相分析和粒径计算、原子力显微镜(AFM)和透射电子显微镜(TEM)形貌观察、振动样品磁强计磁性测定等进行表征,结果表明制备的Fe3O4粉体平均粒径约为24nm、粒度分布均匀、分布带较窄且产物纯度高;该粉体具有超顺磁性,饱和磁化强度在66A·m2/kg左右.     

巯基表面修饰磁性复合纳米粒子用于重金属离子去除的研究

采用化学共沉淀法合成磁性Fe3O4纳米粒子,并且利用正硅酸乙酯(TEOS)的水解和凝聚作用在Fe3O4纳米粒子表面沉积包覆一层SiO2,合成核壳式的Fe3O4@SiO2复合纳米粒子。以Fe3O4@SiO2纳米粒子为基体,将(3-巯基丙基)三乙氧基硅烷嫁接到纳米粒子表面,制备出巯基功能化的纳米材料,将其应用于对重金属离子的吸附。由于功能化纳米粒子具有超顺磁性,为纳米粒子吸附重金属粒子后的分离提供了便利。通过TEM、XRD、FTIR、VSM等手段对Fe3O4@SiO2复合纳米粒子进行表征。     

Fe3O4/CdTe磁性荧光纳米复合物的逐步杂凝聚法合成及其表征

采用逐步杂凝聚法合成了Fe3O4/CdTe磁性荧光纳米复合物.以化学共沉淀法制备Fe3O4纳米颗粒,经油酸修饰后分散在表面活性剂中形成磁流体.CdTe量子点以巯基乙酸为稳定剂制得.最后以聚乙烯亚胺(PEI)为联接剂,成功制备了Fe3 O4 /CdTe磁性荧光双功能纳米复合物颗粒.该复合物颗粒平均尺寸为(30±5)nm,荧光产率为0.186,饱和磁化强度为15.745emu/g,该纳米粒子既具有优异的荧光特性,也具有较强的超顺磁性.     

两水亲性嵌段共聚物修饰Fe_3O_4磁纳米粒子的一步合成及性能表征

采用可逆加成-断裂链转移(RAFT)聚合,合成了两水亲性嵌段共聚物聚(4乙烯基吡啶)-b-聚(甲基丙烯酸聚乙二醇酯)(P4VP-b-PMAPEG)和聚(丙烯酸)-b-聚(甲基丙烯酸聚乙二醇酯)(PAA-bPMAPEG),通过多元醇还原法制备了两水亲性嵌段共聚物修饰的Fe3O4磁纳米粒子。并利用红外光谱(FT-IR)、X射线粉末衍射(XRD)、透射电镜(TEM)对磁纳米粒子进行表征。结果表明,嵌段共聚物修饰的Fe3O4磁纳米粒子为大小均匀的球状颗粒,其粒径在10~20nm。振动样品磁强计测试结果显示,在室温、外加磁场下,经PAA-b-PMAPEG及P4VP-bPMAPEG修饰的Fe3O4磁纳米粒子的饱和磁化强度分别为63.1A·m2/kg和50.2A·m2/kg,该磁纳米粒子均呈现超顺磁性。     

微波辐射乳液聚合制备聚氰基丙烯酸正丁酯磁性微球

通过化学共沉淀法制备Fe3O4纳米粒子,再用油酸钠和十二烷基磺酸钠(SDS)对Fe3O4进行改性,制得稳定的水基磁流体。在自制的磁流体存在下,以氰基丙烯酸正丁酯(BCA)为单体,用微波辐射乳液聚合的方法制备了Fe3O4/聚氰基丙烯酸正丁酯磁性微球。并用X射线衍射仪(XRD),透射电子显微镜(TEM),傅立叶红外光谱仪(FT-IR),振动样品磁强计(VSM)对制备的磁性高分子微球的结构形貌和磁性能进行表征测试。结果表明,在适当的pH值条件下,得到了粒径为150 nm~200 nm,饱和磁化强度为20.23 emμ/g,粒径均一的聚氰基丙烯酸正丁酯磁性微球。     

静电纺丝法制备PAN/Fe3O4磁性纳米纤维

采用化学共沉淀法制备纳米四氧化三铁,选用曲拉通X-100为分散剂,利用静电纺丝法制备PAN/Fe3O4磁性纳米复合材料。X射线衍射仪(XRD)验证了四氧化三铁在复合纳米纤维中的存在。同时使用扫描电镜(SEM)和透射电镜(TEM)对复合纳米纤维的微观形貌和Fe3O4在纤维中的分布进行了观察,利用热重(TGA)对纳米复合材料的热稳定性进行分析;通过磁性实验分析了纳米复合材料的磁性性能。结果表明,所制备PAN/Fe3O4磁性纳米纤维成型良好,且Fe3O4磁性颗粒在纤维中分散均匀,其与PAN是物理复合。纳米复合材料具有一定磁性,并可由磁性颗粒的加入量进行控制。     

磁性羧甲基化壳聚糖纳米粒子的制备与表征

以化学共沉淀法制备了Fe3O4纳米粒子,壳聚糖经羧甲基化改性后接枝在Fe3O4颗粒表面,得到了磁性羧甲基化壳聚糖(Fe3O4/CMC)纳米粒子.利用透射电镜(TEM)、X射线衍射(XRD)、傅立叶红外光谱(FT-IR)及磁性测试对产物进行了表征.TEM表明Fe3O4纳米粒子被CMC包覆,粒径约10 nm;XRD分析表明复合纳米粒子中磁性物质为Fe3O4;FT-IR表明壳聚糖发生羧甲基反应以及在Fe3O4表面的接枝反应.Fe3O4/CMC纳米粒子具有超顺磁性,比饱和磁化强度25.73 emu/g,有良好的磁稳定性.     

Green fabrication of agar-conjugated Fe3O4 magnetic nanoparticles

Magnetic nanoparticles are of great interest both for fundamental research and emerging applications. In the biomedical field, magnetite (Fe(3)O(4)) has shown promise as a hyperthermia-based tumor therapeutic. However, preparing suitable solubilized magnetite nanoparticles is challenging, primarily due to aggregation and poor biocompatibility. Thus methods for coating Fe(3)O(4) NPs with biocompatible stabilizers are required. We report a new method for preparing Fe(3)O(4) nanoparticles by co-precipitation within the pores of agar gel samples. Permeated agar gels were then dried and ground into a powder, yielding agar-conjugated Fe(3)O(4) nanoparticles. Samples were characterized using XRD, FTIR, TGA, TEM and SQUID. This method for preparing agar-coated Fe(3)O(4) nanoparticles is environmentally friendly, inexpensive and scalable.     

Facile synthesis of monodisperse superparamagnetic Fe3O4/PMMA composite nanospheres with high magnetization

Monodisperse superparamagnetic Fe(3)O(4)/polymethyl methacrylate (PMMA) composite nanospheres with high saturation magnetization were successfully prepared by a facile novel miniemulsion polymerization method. The ferrofluid, MMA monomer and surfactants were co-sonicated and emulsified to form stable miniemulsion for polymerization. The samples were characterized by DLS, TEM, FTIR, XRD, TGA and VSM. The diameter of the Fe(3)O(4)/PMMA composite nanospheres by DLS was close to 90 nm with corresponding polydispersity index (PDI) as small as 0.099, which indicated that the nanospheres have excellent homogeneity in aqueous medium. The TEM results implied that the Fe(3)O(4)/PMMA composite nanospheres had a perfect core-shell structure with about 3 nm thin PMMA shells, and the core was composed of many homogeneous and closely packed Fe(3)O(4) nanoparticles. VSM and TGA showed that the Fe(3)O(4)/PMMA composite nanospheres with at least 65% high magnetite content were superparamagnetic, and the saturation magnetization was as high as around 39 emu g(-1) (total mass), which was only decreased by 17% compared with the initial bare Fe(3)O(4) nanoparticles.     

Poly(amidoamine)-Grafted Superparamagnetic Iron Oxide Nanoparticles: Synthesis and Characterization

In this study, the surface of amino silane modified magnetite nanoparticles were coated with polyamidoamine dendrimer up to the fifth generation via a modified repetitive Michael addition and amidation processes. Products were characterized with X-ray powder diffractometry (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), thermal gravimetry (TG), and vibrating sample magnetometry (VSM) which proved the superparamagnetic properties of all products. The attachment of silane group and PAMAM (poly(amidoamine) dendrimers on the surface of the magnetite nanoparticles were confirmed with both TG and FT-IR. Due to the given saturation magnetization (M _s) of the products, they may be a powerful tool for biomedical applications and catalysis chemistry.     

A facile synthesis of PEG-coated magnetite (Fe3O4) nanoparticles and their prevention of the reduction of cytochrome c

We report here a facile and green synthetic approach to prepare magnetite (Fe(3)O(4)) nanoparticles (NPs) with magnetic core and polyethylene glycol (PEG) surface coating. The interaction of the bare and PEG-coated Fe(3)O(4) NPs with cytochrome c (cyt c, an important protein with direct role in the electron transfer chain) is also reported in this study. With ultrasonication as the only peptization method and water as the synthesis medium, this method is easy, fast, and environmentally benign. The PEG coated NPs are highly water dispersible and stable. The bare NPs have considerable magnetism at room temperature; surface modification by PEG has resulted in softening the magnetization. This approach can very well be applicable to prepare biocompatible, surface-modified soft magnetic materials, which may offer enormous utility in the field of biomedical research. Detailed characterizations including XRD, FTIR, TG/DTA, TEM, and VSM of the PEG-coated Fe(3)O(4) NPs were carried out in order to ensure the future applicability of this method. Although the interaction of bare NPs with cyt c shows reduction of the protein, efficient surface modification by PEG prevents its reduction.     

聚乙二醇法在温和条件下制备不同结构的磁性Fe3O4纳米晶

以Fe（acac）3为原料,乙二醇、聚乙二醇1000和聚乙二醇5000为还原剂和溶剂,在温和的溶剂热的条件下制备了不同尺寸的顺磁性Fe3O4纳米颗粒.利用X射线衍射（XRD）、光电子能谱（XPS）、透射电子显微镜（TEM）和磁性测量技术对制备的Fe3O4纳米颗粒的结构、形貌、磁性能进行了表征测试.结果发现,聚乙二醇分子链的长度对Fe3O4纳米颗粒的平均粒径大小、结晶度和饱和磁化强度均有重要影响.以乙二醇、聚乙二醇1000和聚乙二醇5000为还原剂制备的Fe3O4纳米颗粒的尺寸分别为2～3nm、5nm和7～8nm;相应的纳米Fe3O4颗粒饱和磁化强度分别为55.2、61.5和81.3emu/g;同时结晶度也随分子链的增加而增加.随分子链长度的增加,还原剂还原性的逐渐增加是导致Fe3O4纳米颗粒平均粒径大小、结晶度和饱和磁化强度逐渐增大的重要因素.     

Preparation and characterization of Ni-nitrilotriacetic acid bearing poly(methacrylic acid) coated superparamagnetic magnetite nanoparticles

Stable superparamagnetic magnetite (Fe3O4) nanoparticles were synthesized via co-precipitation in the presence of poly(methacrylic acid) (PMAA) in aqueous solution. The polymer coated Fe3O4 nanoparticles were characterized using transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction, thermal analysis, and vibrating sample magnetometry (VSM) techniques. These measurements reveal the presence of magnetite nanoparticles with a size of approximately 8 nm inside the PMAA matrix. The magnetization value of these superparamagnetic nanoparticles at room temperarure and 7 T was measured as about 40 emu/g. PMAA-coated Fe3O4 nanoparticles were further assembled with Ni-chelate through a reaction between a primary amine-bearing NTA (nitrilotriacetic acid) ligand and carboxy-functional groups of PMAA. NTA-PMAA-coated magnetite nanoparticles were then loaded with nickel ions and characterized using FTIR. The average amount of binded Ni on the surface of the NTA-modified PMAA coated Fe3O4 was calculated as 1.65 +/- 0.3 x 10(-6) mol nickel(II) ions per g of the magnetic particles from the inductively coupled plasma optical emission spectroscopy (ICP-OES) measurements.     

纳米Fe2O3粒子修饰/填充碳纳米管的可控制备

为研究碳纳米管填充和负载的可控制备,通过沉积负载方法和湿化学填充法制备了不同负载率和填充率的碳纳米管,采用红外光谱仪、X射线衍射仪、高分辨透射电子显微镜和热重分析仪进行了结构表征分析.研究结果表明,负载率和填充率与C和Fe的比例有关.当C与Fe的质量比为4∶1或8∶1时,负载率分别为28.52%或16.17%,填充率分别为11.32%或9.43%.