聚乙二醇-四氧化三铁纳米粒子复合材料的结构、物理性质及应用

在β-环糊精作保护剂条件下, 制备了高对称的十八面体四氧化三铁(Fe₃O₄)纳米材料. 通过胶体化学方法, 合成了一系列不同起始计量比的聚乙二醇(PEG)和Fe₃O₄纳米粒子复合物(CM-1-CM-4). 这些PEG复合材料展示出重要特性: 首先, 它们的表面形貌依赖于Fe₃O₄的计量; 其次, PEG的熔化过程受Fe₃O₄的影响, 并且直接与Fe₃O₄的含量相关; 进一步研究表明, 除CM-4外, Fe₃O₄的引入导致PEG结晶度下降, 而且Fe₃O₄纳米粒子量越少, 降低幅度越大; 更为有趣的是, PEG的降解过程受制于Fe₃O₄纳米粒子的影响, 导致不同降解产物的出现; 而且, 与纯Fe₃O₄纳米粒子一样, 复合材料中的Fe₃O₄也显示典型的软铁磁性行为, 但饱和磁化强度相对较小; 此外, X射线光电子能谱(XPS)实验揭示在这些PEG复合材料中, 有从Fe到O的电子转移, Fe电子密度的降低可用来解释复合材料饱和磁化强度的减小; 最后, 这些PEG复合材料呈现出对有机染料的表面增强拉曼效应, 并且这种效应随Fe₃O₄纳米粒子含量的增加而增加. 这些结果将会对聚合物/无机纳米粒子复合材料的发展起到推进作用.     

混合表面活性剂体系聚苯乙烯/Fe3O4复合纳米粒子的制备

在TritonX-100/十二烷基苯磺酸钠混合表面活性剂体系中，制得核-壳型结构的聚苯乙烯/Fe₃O₄复合纳米粒子。通过X-射线衍射、傅立叶红外光谱测定表明，复合纳米粒子结构组成以Fe₃O₄为核_，聚苯乙烯为壳，证明聚苯乙烯在Fe₃O₄纳米粒子上的包覆是成功的。电子显微镜观察结果表明：Fe₃O₄纳米粒子的粒径约10 nm，聚苯乙烯/Fe₃O₄复合纳米粒子的粒径为25-35 nm。     

可回收Fe3O4@SiO2-Ag磁性纳米微球对染料污染物的快速脱色处理

介绍了一种采用无毒廉价的前驱物制备Fe₃O₄@SiO₂-Ag磁性纳米微球的快捷方法,制备的Fe₃O₄@SiO₂-Ag纳米微球在NaBH₄存在下可以催化还原染料污染物.实验结果表明,Fe₃O₄@SiO₂-Ag磁性纳米粒子保持了Ag纳米粒子和Fe₃O₄纳米粒子的双重优点,不仅对染料罗丹明B和曙红Y具有良好的催化还原效率,而且可以在外加磁场作用下从溶液中快速有效的分离.催化还原反应速率与反应温度及Fe₃O₄@SiO₂-Ag催化剂用量有关,反应体系中表面活性剂和无机盐(Na₂SO₄)的存在也会影响催化剂的催化活性.该Fe₃O₄@SiO₂-Ag磁性纳米粒子在工业染料污染物处理方面具有应用前景.     

用于高效去除水中孔雀石绿的三层结构磁性复合材料Fe3O4@聚丙烯酸@ZiF-8的制备

设计并合成了一种以磁性纳米粒子为核，聚合物为中间层，金属有机骨架材料为外层的三层结构磁性复合材料(Fe₃O₄@PAA@ZIF 8)。首先利用溶剂热法制备Fe₃O₄纳米粒子，然后通过蒸馏沉淀聚合法在Fe₃O₄纳米粒子表面包覆聚丙烯酸(PAA)层，最后通过原位沉积法在PAA外部包覆ZIF 8。在对Fe₃O₄@PAA@ZIF 8的组成和结构进行表征的基础上，深入研究其对孔雀石绿(MG)的吸附性能。透射电子显微镜(TEM)显示 Fe₃O₄@PAA@ZIF 8 具有明显的三层结构，Fe₃O₄的平均粒径为 117nm，PAA 层厚度约为 17 nm，ZIF 8层的厚度约为 14 nm。Fe₃O₄@PAA@ZIF 8对 MG 的吸附量随着 pH 的升高而增大，吸附过程符合准二阶动力学模型和 Langmuir等温吸附模型。此外，Fe₃O₄@PAA@ZIF 8还表现出良好的重复利用性能，8次循环利用后对MG(500 mg·L^-1)的最大吸附量仍可达982 mg·g^-1。     

Fe3O4/PEI/Au@CdSe/CdS多功能复合材料的制备与表征

以共沉淀法制备出Fe₃O₄纳米粒子,通过聚乙烯亚胺(PEI)修饰Fe₃O₄纳米粒子,再原位复合上Au纳米粒子,制得Fe₃O₄/PEI/Au纳米颗粒微球。再将Fe₃O₄/PEI/Au纳米颗粒与巯基乙酸修饰的量子点CdSe/CdS连接,成功制备了Fe₃O₄/PEI/Au@CdSe/CdS多功能复合微球。经过傅里叶变换红外光谱仪(FTIR)、荧光分光光度计、荧光显微镜、X射线衍射(XRD)、透射电子显微镜(TEM)及振动样品磁强计(VSM)的表征。结果表明:多功能复合微球的粒径在40nm左右,具有超顺磁性,剩磁,矫顽力近似等于零,饱和磁化强度为28.83A·m₂·kg^-1,同时兼有优越的荧光性能和金纳米粒子的特性。     

Fe3O4/PEI/Au@CdSe/CdS多功能复合材料的制备与表征

以共沉淀法制备出Fe₃O₄纳米粒子,通过聚乙烯亚胺(PEI)修饰Fe₃O₄纳米粒子,再原位复合上Au纳米粒子,制得Fe₃O₄/PEI/Au纳米颗粒微球。再将Fe₃O₄/PEI/Au纳米颗粒与巯基乙酸修饰的量子点CdSe/CdS连接,成功制备了Fe₃O₄/PEI/Au@CdSe/CdS多功能复合微球。经过傅里叶变换红外光谱仪(FTIR)、荧光分光光度计、荧光显微镜、X射线衍射(XRD)、透射电子显微镜(TEM)及振动样品磁强计(VSM)的表征。结果表明:多功能复合微球的粒径在40 nm左右,具有超顺磁性,剩磁,矫顽力近似等于零,饱和磁化强度为28.83 A·m²·kg^-1,同时兼有优越的荧光性能和金纳米粒子的特性。     

Fe3O4@SiO2@polymer复合粒子的制备及在药物控制释放中的应用

本文通过多步反应制备了一种新型的、多层结构的、多功能的磁性纳米复合粒子, (Fe₃O₄@SiO₂@polymer). 纳米复合粒子内核是磁性Fe₃O₄纳米粒子, SiO₂包裹在Fe₃O₄上能够使其稳定分散和保护其不被腐蚀氧化; 中间层是生物相容的聚天冬氨酸(PAsp)载药层; 最外层是亲水的聚乙二醇(PEG)稳定层. 磁性纳米复合粒子各层都是生物相容的, 利用静电作用将抗癌药物阿霉素(DOX)负载在磁性纳米复合粒子中, 通过PAsp的pH响应调节了DOX的释放速率.     

磁性高强度聚丙烯酰胺/Fe3O4纳米复合水凝胶

以辐射过氧化的表面活性剂胶束为引发中心和交联中心, 制得具有优异机械性能的聚丙烯酰胺(PAAm)水凝胶, 并通过原位化学共沉淀法向其中引入Fe₃O₄粒子, 得到了磁性复合水凝胶. 扫描电子显微镜(SEM)表征发现磁性粒子在凝胶中分布均匀, 其粒径约为30 nm. X射线衍射(XRD)表征证实所引入的纳米粒子为尖晶石型Fe₃O₄. 磁性能测试表明, PAAm/ Fe₃O₄复合水凝胶具有超顺磁性特征. 该复合凝胶具有较优异的机械性能, 其断裂伸长率可以达到1200%, 拉伸强度最大可达0.10 MPa. 另外, 该复合凝胶表现出良好的形变回复特性.     

Pd/Fe3O4-MCNT磁性催化剂的制备、表征及催化性能

利用多元醇法制备了单分散Fe₃O₄纳米粒子修饰多壁碳纳米管(MCNT)的磁性复合材料, 并以X射线衍射(XRD)、透射电镜(TEM)和X射线能量色散谱(EDS)对碳纳米管磁性复合材料的结构和组成进行了表征. 研究发现, 通过调控Fe₃O₄前驱体与MCNT载体的质量比, 可以很好地控制沉积的磁性纳米粒子大小. 以碳纳米管磁性复合材料为载体, 采用多元醇法成功制备了Pd负载量为3.0% (w)的Pd/Fe₃O₄-MCNT磁性催化剂. 磁性质测试表明碳纳米管磁性复合材料在负载Pd前后都具有良好的超顺磁性. 以肉桂醛加氢为探针反应研究了Pd/Fe₃O₄-MCNT的催化性能, 结果表明该催化剂表现出良好的催化加氢性能, 在外加磁场下催化剂能与液相反应体系高效分离, 循环使用4次后, 催化性能没有明显下降, 显示了良好的循环利用性能.     

ATP适体接枝Fe3O4纳米粒子的制备及化学发光酶检测应用

制备了油酸修饰的Fe₃O₄纳米粒子,利用盐酸多巴胺对其表面进行氨基化改性,制得水分散性良好的Fe₃O₄纳米粒子,用X射线衍射、透射电镜、傅里叶变换红外光谱仪、振动样品磁强计和紫外-可见吸收光谱进行表征。随后,将氨基修饰的三磷酸腺苷（ATP）适体接枝到Fe₃O₄纳米粒子上,结合荧光素酶化学发光法进行ATP的定量检测,并应用于市售酸奶中乳酸菌ATP含量的检测,其灵敏度高、重现性好。各项实验结果表明所制备的Fe₃O₄纳米粒子是一种分散性好、易分离的载体,其粒径均一、稳定、磁性强、与适体结合性能好,拓展了Fe₃O₄纳米粒子在分析检测领域的应用。     

Conducting and magnetic behaviors of monodispersed iron oxide/polypyrrole nanocomposites synthesized by in situ chemical oxidative polymerization

This study describes the preparation of nanocomposites fabricated from monodispersed iron oxide (Fe₃O₄) and polypyrrole (PPy) by in situ chemical oxidative polymerization. The monodispersed 4 nm Fe₃O₄ nanoparticles which served as cores were synthesized using the thermal decomposition of a mixture of Iron (III) acetylacetonate and oleic acid in the presence of high boiling point solvents. The resulting nanoparticles were further dispersed in an aqueous solution with anionic surfactant sodium bis(2‐ethylhexyl) sulfosuccinate to form micelle/Fe₃O₄ spherical templates that avoid the aggregation of Fe₃O₄ nanoparticles during the further preparation of the nanocomposites. The Fe₃O₄/PPy nanocomposites were then synthesized via in situ chemical oxidative polymerization on the surface of the spherical templates. Both field‐emission scanning electron microscopy (FESEM) and high‐resolution transmission electron microscopy (HRTEM) images indicate that the resulting Fe₃O₄ nanoparticles are close to spherical dots with a particle size of about 4 nm and a standard deviation of less than 5% (4 ± 0.2 nm). Structural and morphological analysis using FESEM and HRTEM showed that the fabricated Fe₃O₄/PPy nanocomposites are core (Fe₃O₄)‐shell (PPy) structures. Morphology of the nanocomposites shows a remarkable change from spherical to tube‐like structures as the content of monodispersed Fe₃O₄ nanoparticles increases from 9% up to 24 wt %. The conductivities of these Fe₃O₄/PPy nanocomposites are about six times higher than those of PPy without Fe₃O₄. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 4647–4655, 2007     

Alginate-Coated Fe3O4 Hollow Microspheres for Drug Delivery

Novel hollow Fe₃O₄ nanoparticles for drug delivery were synthesized via a one-step templatefree approach. These nanoparticles were obtained by modifing the Fe₃O₄ nanoparticles with 3-aminopropyltrimethoxy silane, and then grafting alginate onto the surface of amine magnetic. The hollow structure of Fe₃O₄ spheres was characterized by TEM, XRD, and XPS. The M-H hysteresis loop indicated that the magnetic spheres exhibit superparamagnetic characteristics at room temperature. Daunorubicin acting as a model drug was loaded into the carrier, and the maximum percent of envelop and load were 28.4% and 14.2% respectively. The drug controlled releasing behaviors of the carriers were compared in different pH media.     

A facile two-step modifying process for preparation of poly(SStNa)-grafted Fe3O4/SiO2 particles

This article reports the synthesis of the poly(sodium 4-styrenesulfonate)-grafted Fe₃O₄/SiO₂ particles via two steps. The first step involved magnetite nanoparticles (Fe₃O₄) homogeneously incorporated into silica spheres using the modified Stöber method. Second, the modified silica-coated Fe₃O₄ nanoparticles were covered with the outer shell of anionic polyelectrolyte by surface-initiated atom transfer radical polymerization. The resulted composites were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersive microscopy (EDS), Fourier transform-infrared (FT-IR), thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS) and vibration sample magnetometer (VSM). The XRD results indicated that the surface modified Fe₃O₄ nanoparticles did not lead to phase change compared with the pure Fe₃O₄. TEM studies revealed nanoparticles remained monodisperse. The detection of sulfur and sodium signals was a convincing evidence that sodium 4-styrenesulfonate was grafted onto the surface of the magnetic silica in XPS analysis. Finally, super-paramagnetic properties of the composite particles, and the ease of modifying the surfaces may make the composites of important use in mild separation, enzyme immobilization, etc.     

Hydrothermal synthesis of monodisperse Fe3O4 nanoparticles based on modulation of tartaric acid

In this paper, monodisperse Fe₃O₄ nanoparticles with single crystalline structure were synthesized via a facile environment-friendly method. And the size of the nanoparticles ranges from 10 nm to 15 nm. As-synthesized Fe₃O₄ were characterized by X-ray diffraction instrument (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FT-IR) spectrometer and field emission transmission electron microscope (FE-TEM). The effect of tartaric acid (TA) amount on products was investigated by XRD and TEM. The results indicated that TA could commendably modulate the crystalline phase, morphology and size of nanometer Fe₃O_4. A possible generated mechanism of Fe₃O₄ crystals was proposed in virtue of UV–vis absorption spectra. Besides, the magnetic properties of as-synthesized Fe₃O₄ were detected.     

Synthesis and characterization of novel magnetic Fe3O4/polyphosphazene nanofibers

Novel magnetic Fe₃O₄/polyphosphazene nanofibers were successfully prepared via a facile approach by ultrasonic irradiation. The structure and morphology were characterized by SEM, TEM, EDX, IR and XRD. The characterization results show that the magnetic Fe₃O₄/polyphosphazene nanofibers are several microns in length and 50–100 nm in diameter with Fe₃O₄ nanoparticles of 5–10 nm attached on the surface. The interaction between Fe₃O₄ nanoparticles and polyphosphazene nanofibers was thought as coordination behavior. TG curves show that the magnetic Fe₃O₄/polyphosphazene nanofibers have good thermostability and high magnetism content of about 44%. Magnetic studies show that the magnetic nanofibers exhibit good superparamagnetic properties with high magnetization saturation value of about 36 emu/g.     

Synthesis and Characterization of the Superparamagnetic Fe<Subscript>3</Subscript>O<Subscript>4</Subscript>/Ag Nanocomposites

The study of superparamagnetic Fe₃O₄/Ag nanocomposites have received great research attention due to their wide range of potential applications in biomedicine. In this report, an easy microemulsion reaction was employed to synthesis Fe₃O₄/Ag nanocomposites with self-aggregated branch like nanostructures. The Fe₃O₄ nanoparticles were initially prepared and subsequently AgNO₃ was reduced as Ag by chemical reduction method. The results showed that the average size of the Fe₃O₄/Ag nanocomposites were in the range of 10 ± 2 nm. These nanoparticles were self-aggregated as a branch like nanostructure. The optical properties of Fe₃O₄ nanoparticles were modified with surface plasmon resonance of Ag nanoparticles. The observed saturation magnetization of superparamagnetic Fe₃O₄/Ag nanocomposites were 40 emu/g.     

纳米Fe_3O_4及钴离子掺杂Fe_3O_4:有机碱共沉淀制备和磁性质

以有机碱四甲基氢氧化铵(TMAH)为沉淀剂合成了纳米Fe3O4和Co2+掺杂的纳米Fe3O4粒子。分别讨论了碱用量,铁盐溶液浓度,反应温度,有机碱及PEG-4000的分散性等因素对纳米Fe3O4的形貌影响。结果表明,所合成的纳米Fe3O4为30nm左右的反尖晶石型面心立方结构,有机碱除了起沉淀剂作用,还能够提高纳米Fe3O4的分散性。本文还讨论了不同Co2+掺入量的纳米Fe3O4粒子的磁性质,结果表明Co2+掺杂的纳米Fe3O4粒子的矫顽力在不同掺入量的下有较大的改变。当Co2+掺入量为10.0%时,纳米Fe3O4的矫顽力达到最大值,为1628Oe。     

Self-assembly approach for the synthesis of electro-magnetic functionalized Fe3O4/polyaniline nanocomposites: Effect of dopant on the properties

Electro-magnetic functionalized Fe₃O₄/polyaniline (PANI) nanocomposites were synthesized by chemical oxidative polymerization in the presence of ammonium peroxydisulfate as an oxidizing agent. Polymerization was carried out independently using two different types of dopants, organic acids (camphorsulfonic acid (CSA) and p-toluenesulfonic acid (TSA)) and inorganic acid (hydrochloric acid). A plausible mechanism for the formation of the nanocomposites (NCs) is presented. During the formation of NCs, CSA/TSA also serves as a micellar template, whereas micelle formation is absent in the case of HCl. Fe₃O₄/PANI-CSA-NC, Fe₃O₄/PANI-TSA-NC and Fe₃O₄/PANI-HCl-NC were characterized for morphology, molecular structure, electrical conductivity and magnetic properties by transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), UV–visible spectroscopy (UV–vis) and superconductor quantum interference device (SQUID) measurements. The results indicate that dopant influence the properties of the NCs. TEM photographs of Fe₃O₄/PANI-CSA and Fe₃O₄/PANI-TSA reveal that the composite particles are spherical having a layer of PANI-CSA or PANI-TSA over Fe₃O₄ nanoparticles. Fe₃O₄/PANI-CSA-NC and Fe₃O₄/PANI-TSA-NC have better morphology, conductivity and high magnetic saturation (M_s) than that of Fe₃O₄/PANI-HCl-NC. Under applied magnetic field, the NCs exhibit the hysteresis loops of the ferromagnetic behavior. M_s value varies with content of Fe₃O₄ present in the composites.