超顺磁性Fe3O4纳米颗粒的制备及修饰

利用2-吡咯烷酮和乙酰丙酮铁为原料制备出Fe3O4磁性纳米粒子,选择偶联剂γ-氨丙基三乙氧基硅烷(NH2C3H6Si(OC2H5)3)对磁性材料进行了表面修饰.经XRD、TEM、VSM、FT-IR测试结果表明,制备出的Fe3O4磁性纳米粒子粒径均一(8～10nm)、结晶度高、磁响应较强;通过控制反应回流时间,可以改变粒子的大小;经表面改性以后,-OH、-NH、-NH2、-C-O、-C-OH等多种功能基团负载到磁性Fe3O4纳米粒子表面,增强了微球的生物相容性.     

共沉淀制备不同粒径Fe3O4纳米颗粒及磁性能的研究

以氯化铁(FeCl3·6H2O)和氯化亚铁(FeCl2·4H2O)为原料,氢氧化钠(NaOH)为沉淀剂,在无表面活性剂作用下共沉淀制备出了不同粒径的Fe3O4纳米颗粒.采用X射线衍射(XRD)、透射电子显微镜(TEM)和振动样品磁强计(VSM)对产物的晶体结构、形貌、粒径及磁性能进行了表征.实验结果表明,n(Fe2+)...     

混有Fe_3O_4纳米颗粒的PDMS薄膜磁力激励变形研究

采用聚二甲基硅氧烷(PDMS)为基体,以经硅烷偶联剂(KH-570)处理过的20nm Fe3O4纳米颗粒为填充物,将这两种材料以不同比例进行混合得到磁性PDMS薄膜,对该磁性薄膜受力进行理论分析,用微米X射线三维成像系统测试同一永磁铁激励下不同半径、支撑腔体不同高度下(磁性薄膜距离永磁铁高度)和Fe3O4纳米颗粒不同质量分数下磁性薄膜的变形大小,以及不同表面磁场强度的永磁铁激励下磁性薄膜的变形大小,通过振动样品磁强计对磁性薄膜样品的磁滞曲线进行了检测,实验结果表明,在相同的激励下半径越大、支撑腔体高度越小、质量分数越大薄膜中心位移越大,不同激励下永磁铁磁场强度越大薄膜中心位移的也越大,与理论分析一致。薄膜变形引起空腔内的体积变化,体积变化证明了薄膜驱动液体的能力,该实验为应用于微流体中的微泵提供了理论依据。     

磁性纳米Fe3O4的制备与应用进展

总结了磁性纳米Fe3O4粒子的微乳液法、热分解铁有机物法、共沉淀法、凝胶-溶胶法、生物模板合成法等.并讨论了磁性纳米Fe3O4粒子在生物分离、靶向药物、肿瘤磁热疗以及免疫检测等领域的应用.     

靶向药物载体-纳米级磁性氧化铁的合成与性能

研究了纳米级磁性氧化铁的合成工艺和生成产物粒径之间的关系 ,探究了各种因素对Fe3O4 粒径及其分布的影响。结果表明 ,反应体系的 pH值、二价和三价铁离子的摩尔比以及反应温度等均对产物的粒径有不同程度的影响。粒子分散性的研究显示 ,由纯粹反应成分组成的体系中生成的Fe3O4 粒子会相互聚集 ,形成大的具有次级结构的宏观粒子 ,而加入表面活性剂后 ,可有效的防止这种现象的发生 ,粒子的分散性明显变好。     

氧化硅-磁性Fe3O4复合纳米粒子的制备及应用

采用溶胶-凝胶法通过正硅酸四乙酯（TEOS）碱催化水解,在Fe₃O₄纳米粒子表面包裹氧化硅。利用生物倒置显微镜、场发射透射电镜、X射线衍射仪、激光粒度仪、振动样品磁强计对氧化硅/Fe₃O₄复合粒子的外貌、粒径及粒径分布、饱和磁化强度、化学成分进行了表征。结果表明,所制得的复合粒子性能良好,粒径在15 nm左右,饱和磁化强度为109 emu/g。用该磁性纳米复合粒子提取质粒DNA和基因组DNA取得良好的效果,可用于食品中致病菌的分析判定和疾病的基因诊断分析。     

Deposition of CuWO4 nanoparticles over g-C3N4/Fe3O4 nanocomposite: Novel magnetic photocatalysts with drastically enhanced performance under visible-light

Novel g-C₃N₄/Fe₃O₄/CuWO₄ nanocomposites, as magnetic visible-light-driven photocatalysts, fabricated through a simple refluxing-calcination process. The synthesized photocatalysts were characterized by a series of techniques including XRD, EDX, SEM, TEM, HRTEM, FT-IR, TGA, BET, UV–vis DRS, PL, and VSM. The results showed that heterojunctions are formed between g-C₃N₄, Fe₃O₄, and CuWO₄, which favor suppression of the photogenerated electron/hole pairs from recombination. The resultant g-C₃N₄/Fe₃O₄/CuWO₄ (30%) sample exhibited superior photocatalytic performance. The degradation rate constants on the g-C₃N₄/Fe₃O₄/CuWO₄ (30%) nanocomposite were almost 10.5, 17, 12.5, and 42.5 times higher than those of the pristine g-C₃N₄ for degradations of RhB, MB, MO, and fuchsine, respectively. Moreover, the photocatalyst was magnetically separated and recycled with negligible loss in the activity, which is important for the sustainable photocatalytic processes. Thus, the ternary nanocomposite could have potential applications in different photocatalytic processes.     

CoFe_2O_4@FeCo纳米核壳颗粒的制备与磁性研究

利用化学共沉淀法合成Co Fe2O4纳米颗粒,并在氢气气氛下还原获得Co Fe2O4@Fe Co核壳结构磁性纳米颗粒。用XRD和TEM对所得样品进行结构分析,用SQUID测量样品在300 K时的磁滞回线,发现随着壳厚度的增加,核壳结构样品的矫顽力呈现先增加后减小的趋势,而其饱和磁化强度表现出逐渐增加的趋势。为了探究所制备样品的核壳磁性层之间的交换相互作用,还测量了M-T曲线以及T=5 K时的零磁场冷却(ZFC)和带磁场冷却(FC)磁滞回线。     

Fe3O4／羧甲基化壳聚糖纳米粒子的制备与表征

磁性壳聚糖纳米粒子可用于药物载体及废水处理吸附剂。以化学共沉淀法制备Fe3O4纳米粒子，壳聚糖先进行羧甲基化改性，再经碳二亚胺活化，包履在Fe3O4颗粒表面,透射电镜（TEM）表明，Fe3O4纳米粒子被CMC包履，粒径约10nm；X射线衍射（XRD）分析表明复合纳米粒子中磁性物质为Fe3O4；傅立叶红外光谱（FTIR）表明壳聚糖发生羧甲基反应；磁性测试表明，Fe3O4／CMC具有超顺磁性，饱和磁化强度25.73emu／g，且有良好的磁稳定性。     

Large scale synthesis and characterization of Ni nanoparticles by solution reduction method

Ni nanoparticles were mass synthesized by solution reduction process successfully. The influence of the parameters on the particle size of Ni nanoparticles were studied and the referential process parameters were obtained. The morphology and structure of the synthesized Ni nanoparticles were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) surface area analysis and infrared spectroscopy (IR). The results show that Ni nanoparticles are of high purity and are covered by hydroxyethyl carboxymethyl cellulose (HECMC) layer and the mean size being about 31 nm. The magnetic measurement revealed that Ni nanoparticles are ferromagnetic.     

微乳液体系制备Fe2B包覆纳米α-Fe及其性能研究

采用油包水(W/O)的微乳液体系制备纳米α-Fe.XRD、TEM分析表明,纳米α-Fe被Fe2B所包覆,其粒度在20～100 nm;激光粒度分析表明,纳米α-Fe存在团聚现象,但粒度分布窄;TG-DSC分析表明,纳米α-Fe在＞1100K时发生吸热的α-γ相变;磁强计检测表明,粉体具有铁磁性,其饱和磁化强度为1.14emu/g,剩余磁化强度为0.08emu/g,矫顽力为280Oe.     

Fe3O4纳米颗粒的溶剂热法制备及电磁特性研究

采用溶剂热方法分别在聚乙二醇、三乙二醇溶液中热分解乙酰丙酮铁,得到分散性能良好、尺寸均匀、形貌一致的Fe3O4纳米颗粒,颗粒尺寸为7～8nm。通过X射线衍射及透射电镜研究发现,两种溶液中制备样品均为面心立方结构,且在三乙二醇溶液中制备颗粒分散性更好。分别对两种样品进行磁测量,发现室温时均表现出超顺磁性,398kA/m时的磁化强度分别为50、40A·m2/kg。微波吸收测试显示,颗粒的分散性有利于改善样品的反射损耗。     

多元醇法制备纳米Fe3O4及其静磁性能的研究

以氯化亚铁为前驱物,1,2-丙二醇为还原剂,采用多元醇法意外获得Fe3O4纳米粒子.通过X射线衍射分析标定了获得样品的物相为面心立方结构的Fe3O4,用透射电镜观察了样品的形貌,颗粒形貌为球形,大小为50～70nm,反应机理的研究表明,Fe2 发生了歧化反应,反应主要向氧化的方向进行.用振动样品磁强计表征了样品的静磁性能,测得的饱和磁化强度为74.30A·m2/kg,矫顽力仅为102.68A/m,粒子具有超顺磁性.     

单分散Fe3O4纳米粒子的合成、表征及其自组装

采用高温有机前驱体分解法,以Fe(acac)3为前驱体制备出单分散性较好的Fe3O4纳米粒子,粒径为(6.4±0.90)nm.利用TEM、XRD、HPPS、FTIR等手段对粒子的形貌及性质进行了研究,证实得到的是Fe3O4单晶,粒子表层的铁原子通过共价键和油酸分子中-COO的两个氧原子结合在一起.通过对自组装过程的初步研究表明随磁性纳米粒子浓度的增加,粒子排布逐渐由零星的无规排列变为规整的单层和多层有序结构.     

聚合物包覆纳米铁粒子的结构及其磁性能研究进展

纳米铁粒子具有极大的反应活性而被氧化.本文简要综述了聚合物包覆的纳米铁及其磁性能的研究进展.     

Thermal stability of composites containing HCl-doped polyaniline and Fe nanoparticles

HCl-doped polyaniline (HCl-PANI) powder was mechanically mixed with Fe nanoparticles to obtain the HCl-PANI–Fe composite. The composite pellets containing 30 and 50 wt% Fe nanoparticles were heated in air at 50, 100, 150 and 200 °C for times up to 60 min. The heat treatment degrades the crystallinity of the HCl-PANI and promotes the oxidation of the Fe nanoparticles. After heat-treating, the aromatic structure of PANI is retained in the HCl-PANI and HCl-PANI–Fe pellets. However, the heat treatment causes the dopant dedoping from the polymer backbones. The HCl-PANI–Fe composite pellets heated are in a higher reduction state compared with the unheated ones. Thermogravimetric analysis reveals that a weight loss decreases with increasing the Fe nanoparticle content at the same heating temperature. The weight loss increases rapidly within the first 5-min isothermal time at 200 °C. The conductivity decreases with increasing the heat-treating temperature. A rapid decrease in the conductivity happens within the first 20-min heat-treating time for the HCl-PANI–30 wt% Fe composite and within the first 10-min heat-treating time for the HCl-PANI–50 wt% Fe composite at 200 °C. The composites exhibit a narrow hysteresis curve typical for superparamagnetic nanoparticles and the magnetization behavior is independent of the heat-treating conditions.     

N、Fe双掺杂的纳米TiO2制备及其性能研究

采用溶胶-凝胶法制备了N、Fe双掺杂的纳米TiO2光催化材料.借助XRD、XPS对制备的光催化材料进行表征,并通过晶粒尺寸、晶粒比表面积和晶格畸变率等的分析,研究了N、Fe双掺杂对TiO2性能的影响.研究结果表明,N、Fe双掺杂抑制了TiO2由锐钛矿向金红石的转变,明显延缓了TiO2相的转移;N、Fe双掺杂可明显减小晶...     

Facile synthesis of magnetic iron oxide nanoparticles and their characterization

Magnetic iron oxide nanoparticles are synthesized by suitable modification of the standard synthetic procedure without use of inert atmosphere and at room temperature. The facile synthesis procedure can be easily scaled up and is of important from industrial point of view for the commercial large scale production of magnetic iron oxide nanoparticles. The synthesized nanoparticles were characterized by thermal, dynamic light scattering, scanning electron microscopy and transmission electron microscopy analyses.     

Detection of magnetic nanoparticles against proppant and shale reservoir rocks

With the expansion in the production of shale oil and gas, there is a desire to obtain detailed information of the downhole environment resulting from hydraulic fracturing (fracking). Nanomagnetite (nMag) has been proposed as a suitable contrast agent for magnetic imaging. In order to determine its suitability, 15 nm oleic acid-stabilised magnetite nanoparticles were synthesised and the magnetic susceptibility was measured and compared against two types of proppant. Although frac sand is diamagnetic (?0.20 × 10^?5 SI), ceramic proppant is paramagnetic (25.7 × 10^?5 SI) due to the presence of Fe₂O₃. The quantity of the nanoparticles that would be required for differentiation against the background levels in the proppant pack was calculated to be 0.269 g/L for sand and 1.01 g/L for ceramic, which correlates to a minimum of 15,000 kg and 56,000 kg per well, respectively. In order to determine the contrast with the reservoir rock itself, the magnetic susceptibility was mapped for cores from two typical shale gas reservoirs (Harrison and Rackley, Arkansas), which show a general low level of paramagnetism (ca. 45 × 10^?5 SI). However, regions are observed with higher susceptibility (>200 × 10^?5 SI) necessitating the use of 242,000 kg nMag per well in order to provide contrast with the reservoir.