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1.
To improve the magnetic fluids’ stability and demonstrate the relationships between the bilayercoated structure and the stability, a simple method was proposed for preparingoleic acid bilayercoated Fe3O4 magnetic fluids. The hydrophilic Fe3O4 nanoparticles coated with the bilayer-oleic acid were synthesised by a one-pot process through the chemical co-precipitation under alkaline conditions. Next, the hydrophilic Fe3O4 particles were transformed to hydrophobic particles via carboxyl-protonated modification. Carboxyl-protonated modification was found to be a reversible process, i.e. the lipophilicity of the coated Fe3O4 nanoparticles could be controlled by protonating/ deprotonating the terminal carboxyl group. In addition, the space steric effect could be significantly enhanced by maximising the oleic acid adsorption and increasing the thickness of the coated layer, resulting in the oleic acid bilayer-coated Fe3O4 nanoparticles exhibiting better performance in the stability of the hexanemagnetic fluids than oleic acid monolayer-coated Fe3O4 nanoparticles. 相似文献
2.
Some supramolecular polyacrylate-based liquid crystal polymers (PLCPs) were prepared by polyacrylic acid, a liquid crystal monomer and 3,5-pyridinedicarboxylic acid. Series of magnetic liquid crystal particles (Fe3O4@PLCPs) with core-shell structure were prepared by modifying surface of magnetic nanoparticles Fe3O4 by the PLCPs. The Fe3O4@PLCPs showed a saturation magnetization strength above 51.17 emu/g, which is similar to pure magnetic Fe3O4, indicating good magnetism and magnetic field dependence. Series of magnetorheological fluids were fabricated by Fe3O4@PLCPs (using as dispersed phase) and silicone oil (using as carrier liquid). The effects of mesogen, magnetic particle, and the polymer matrix on magnetorheological performance and settling stability were investigated. The magnetorheological fluid based on 10% Fe3O4@PLCP-1 showed the best performance at an applied magnetic field of 100 mT in this study. Furthermore, the magnetorheological fluids showed excellent settling stability because the density of Fe3O4@PLCPs was lower than that of Fe3O4. The Fe3O4@PLCPs-based fluids presented certain application potential in the field of magnetic fluid due to the excellent magnetorheological effect and settling stability. 相似文献
3.
Hamed Nosrati Soodabeh Davaran Hamidreza Kheiri Manjili Hamed Rezaeejam Hossein Danafar 《应用有机金属化学》2019,33(10)
In this time researchers make a great efforts to develop new hybrid nanoparticles for medical and pharmaceutical applications. Fe3O4‐Au hybrid heterodimers have been prepared with superior properties for various claims. Unfortunately, Fe3O4‐Au heterodimers are not stable in the physiological medium. In this study, we employed the albumin macromolecules as a stabilizer of Fe3O4‐Au hybrid nanoparticles (noted as Fe3O4‐Au‐BSA hybrid nanoparticles). After characterization of synthesized nanoparticles by FTIR, UV–Vis, TEM, DLS, DSC, VSM and XRD techniques, the in vitro and in vivo biocompatibility of these nanoparticles were also evaluated. We encountered with an amazing result which confirmed nanoparticles could be stabilized by linking the BSA on the surface of Fe3O4‐Au heterodimers. Also, intravenous injection of Fe3O4‐Au‐BSA hybrid nanoparticles up to 400 mg/kg to Balb C mice show that these nanoparticles were non‐toxic. The biocompatibility and stereological study had been performed for more than 30 days after nanoparticles administration, using hystomorphometric analysis. Remarkably, to the best of our knowledge, it was the first time the biocompatibility and biodegradability of Fe3O4‐Au were studied and evaluated by stereological technique. Further promotion and biomedical usage of this type of hybrid nanoparticles are underway in our laboratory. 相似文献
4.
《中国化学会会志》2018,65(6):681-686
Fe3O4@Gly nanoparticles were synthetized by coprecipitation and studied in the transesterification of soybean oil and methanol to determine its performance for biodiesel synthesis. The magnetism and catalytic performance of Fe3O4@Gly alkaline catalyst were investigated in detail. With a catalyst dosage 1.5 wt %, methanol/soybean oil ratio of 15:1, reaction temperature of 65 °C, and a reaction time of 3 h, the highest yield of biodiesel was 95.8%. The strong base catalyst CaO was used as comparison, from which it was seen that Fe3O4@Gly was more hydrophobic than the former. Moreover, because of the complete dissolution of oleic acid in methanol, Fe3O4@Gly could make better contact with oleic acid, which made it perform far better than pure CaO in oleic acid. In addition, after four times recycling, the yield of biodiesel was still 86.6%. The results show that Fe3O4@Gly possesses excellent properties of acid resistance and recyclability. The catalyst can be a high‐efficiency alkaline heterogeneous catalyst for biodiesel production. 相似文献
5.
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. 相似文献
6.
Fe3O4@SiO2@polymer复合粒子的制备及在药物控制释放中的应用 总被引:1,自引:1,他引:0
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. 相似文献
7.
Mingliang Ma Yuying Yang Dili Liao Ping Lyu Jinwei Zhang Jianli Liang Lizhi Zhang 《应用有机金属化学》2019,33(2)
A strategy has been developed for the synthesis, characterization and catalysis of magnetic Fe3O4/P(GMA‐EGDMA)‐NH2/HPG‐COOH‐Pd core‐shell structure supported catalyst. The P(GMA‐EGDMA) polymer layer was coated on the surface of hollow magnetic Fe3O4 microspheres through the effect of KH570. The core‐shell magnetic Fe3O4/P(GMA‐EGDMA) modified by ‐NH2 could be grafted with HPG. Then, the hyperbranched glycidyl (HPG) with terminal ‐OH were modified by ‐COOH and adsorbed Pd nanoparticles. The hyperbranched polymer layer not only protected the Fe3O4 magnetic core from acid–base substrate corrosion, but also provided a number of functional groups as binding sites for Pd nanoparticles. The prepared catalyst was characterized by UV–vis, TEM, SEM, FTIR, TGA, ICP‐OES, BET, XRD, DLS and VSM. The catalytic tests showed that the magnetic Fe3O4/P(GMA‐EGDMA)‐NH2/HPG‐COOH‐Pd catalyst had excellent catalytic performance and retained 86% catalytic efficiency after 8 consecutive cycles. 相似文献
8.
In this study, a new magnetic hybrid nanomaterials Fe3O4@SiO2@PPh3@Cr2O72− is introduced. First, the magnetic Fe3O4 nanoparticles have been synthesized by co-precipitation method. Then, tetraethyl orthosilicate has been used for production of core–shell nanoparticles Fe3O4@SiO2. The core–shell magnetic nanoparticles system Fe3O4@SiO2 functionalization was synthesized using (3-chloropropyl) trimethoxysilane and triphenylphosphine and the cationic part was prepared for immobilization of anionic part of the Cr (VI) catalysts including Cr2O72−. After immobilization of the catalyst, its structure was detected by using Fourier transform infrared (FT-IR), solid state UV–Vis, elemental analysis, X-ray fluorescence (XRF), X-ray diffraction (XRD) and the particle size and morphology were elaborated by scanning electron microscope (SEM) and XRD. Magnetism properties were quantified by vibrating sample magnetometer (VSM). 相似文献
9.
ChengLin Wu Huan He HongJun Gao Gan Liu RuJiang Ma YingLi An LinQi Shi 《中国科学:化学(英文版)》2010,53(3):514-518
Novel multifunctional nanoparticles containing a magnetic Fe3O4@SiO2 sphere and a biocompatible block copolymer poly(ethylene glycol)-b-poly(aspartate) (PEG-b-PAsp) were prepared. The silica coated on the superparamagnetic core was able to achieve a magnetic dispersivity, as well as to protect Fe3O4 against oxidation and acid corrosion. The PAsp block was grafted to the surface of Fe3O4@SiO2 nanoparticles by amido bonds, and the PEG block formed the outermost shell. The anticancer agent doxorubicin (DOX) was loaded into the hybrid nanoparticles via an electrostatic interaction between DOX and PAsp. The release rate of DOX could be adjusted by the pH value. 相似文献
10.
Zhong‐Peng Xiao Kun‐Min Yang Hui Liang Jiang Lu 《Journal of polymer science. Part A, Polymer chemistry》2010,48(3):542-550
A reversible addition‐fragmentation chain transfer (RAFT) agent was directly anchored onto Fe3O4 nanoparticles in a simple procedure using a ligand exchange reaction of S‐1‐dodecyl‐S′‐(α,α′‐dimethyl‐α″‐acetic acid)trithiocarbonate with oleic acid initially present on the surface of pristine Fe3O4 nanoparticles. The RAFT agent‐functionalized Fe3O4 nanoparticles were then used for the surface‐initiated RAFT copolymerization of N‐isopropylacrylamide and acrolein to fabricate structurally well‐defined hybrid nanoparticles with reactive and thermoresponsive poly(N‐isopropylacrylamide‐co‐acrolein) shell and magnetic Fe3O4 core. Evidence of a well‐controlled surface‐initiated RAFT copolymerization was gained from a linear increase of number‐average molecular weight with overall monomer conversions and relatively narrow molecular weight distributions of the copolymers grown from the nanoparticles. The resulting novel magnetic, reactive, and thermoresponsive core‐shell nanoparticles exhibited temperature‐trigged magnetic separation behavior and high ability to immobilize model protein BSA. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 542–550, 2010 相似文献
11.
Lu Li Dr. Tingting Wang Lingyu Zhang Prof. Dr. Zhongmin Su Prof. Dr. Chungang Wang Prof. Dr. Rongshun Wang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(36):11417-11422
A method is reported for the first time for the selected-control, large-scale synthesis of monodispersed Fe3O4@C core–shell spheres, chains, and rings with tunable magnetic properties based on structural evolution from eccentric Fe2O3@poly(acrylic acid) core–shell nanoparticles. The Fe3O4@C core–shell spheres, chains, and rings were investigated as anode materials for lithium-ion batteries. Furthermore, a possible formation mechanism of Fe3O4@C core–shell chains and rings has also been proposed. 相似文献
12.
Tzong‐Ming Wu Shiang‐Jie Yen Erh‐Chiang Chen Ray‐Kuang Chiang 《Journal of Polymer Science.Polymer Physics》2008,46(7):727-733
This study describes the preparation of a nanocomposites fabricated from monodispersed 4‐nm iron oxide (Fe3O4) coated on the surface of carboxylic acid containing multi‐walled carbon nanotube (c‐MWCNT) and polypyrrole (PPy) by in situ chemical oxidative polymerization. High‐resolution transmission electron microscopy images and X‐ray diffraction (XRD) data indicate that the resulting Fe3O4 nanoparticles synthesized using the thermal decomposition are close to spherical dots with a particle size about 4 ± 0.2 nm. The resulting nanoparticles were further mixed with c‐MWCNT in an aqueous solution containing with anionic surfactant sodium bis(2‐ethylhexyl) sulfosuccinate to form one‐dimensional Fe3O4 coated c‐MWCNT template for further preparation of nanocomposite. Structural and morphological analysis using field‐emission scanning electron microscopy, high‐resolution transmission electron microscopy, and XRD showed that the fabricated Fe3O4 coated c‐MWCNT/PPy nanocomposites are one‐dimensional core (Fe3O4 coated c‐MWCNT)‐shell (PPy) structures. The conductivities of these Fe3O4 coated c‐MWCNT/PPy nanocomposites are about four times higher than those of pure PPy matrix. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 727–733, 2008 相似文献
13.
Magnetic solid‐phase extraction based on a polydopamine‐coated Fe3O4 nanoparticles absorbent for the determination of bisphenol A,tetrabromobisphenol A, 2,4,6‐tribromophenol,and (S)‐1,1’‐bi‐2‐naphthol in environmental waters by HPLC
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Jia‐yuan Li Xing‐yu Long He‐xing Yin Jun‐qin Qiao Hong‐zhen Lian 《Journal of separation science》2016,39(13):2562-2572
Polydopamine‐coated Fe3O4 magnetic nanoparticles synthesized through a facile solvothermal reaction and the self‐polymerization of dopamine have been employed as a magnetic solid‐phase extraction sorbent to enrich four phenolic compounds, bisphenol A, tetrabromobisphenol A, (S)‐1,1′‐bi‐2‐naphthol and 2,4,6‐tribromophenol, from environmental waters followed by high‐performance liquid chromatographic detection. Various parameters of the extraction were optimized, including the pH of the sample matrix, the amount of polydopamine‐coated Fe3O4 sorbent, the adsorption time, the enrichment factor of analytes, the elution solvent, and the reusability of the nanoparticles sorbent. The recoveries of these phenols in spiked water samples were 62.0–112.0% with relative standard deviations of 0.8–7.7%, indicating the good reliability of the magnetic solid‐phase extraction with high‐performance liquid chromatography method. In addition, the extraction characteristics of the magnetic polydopamine‐coated Fe3O4 nanoparticles were elucidated comprehensively. It is found that there are hydrophobic, π–π stacking and hydrogen bonding interactions between phenols and more dispersible polydopamine‐coated Fe3O4 in water, among which hydrophobic interaction dominates the magnetic solid‐phase extraction performance. 相似文献
14.
Betti base‐modified magnetic nanoparticles as a novel basic nanocatalyst in Knoevenagel condensation and its related palladium nanocatalyst in Suzuki coupling reactions
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Betti base‐modified Fe3O4 nanoparticles have been successfully designed and synthesized for the first time through the condensation of Fe3O4 magnetic nanoparticles coated by (3‐aminopropyl)triethoxysilane with β‐naphthol and benzaldehyde. Their application as a novel magnetic nanocatalyst in the Knoevenagel condensation and also application to immobilization of palladium nanoparticles for Suzuki coupling reactions have been investigated which opens a new field for application of Betti base derivatives in organic transformations. The synthesized inorganic–organic hybrid nanocatalyst has been fully been characterized using Fourier transform infrared, X‐ray diffraction, vibrating sample magnetometry, transmission and scanning electron microscopies, energy‐dispersive X‐ray, wavelength‐dispersive X‐ray and X‐ray photoelectron spectroscopies and inductively coupled plasma techniques. The catalyst was easily separated with the assistance of an external magnet from the reaction mixture and reused for several consecutive runs with no significant loss of its catalytic efficiency. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
15.
In this study, the synthesis of sulfonic acid supported on ferrite–silica superparamagnetic nanoparticles (Fe3O4@SiO2@SO3H) as a nanocatalyst with large density of acidic groups is suggested. This nanocatalyst was prepared in three steps: preparation of colloidal iron oxide magnetic nanoparticles (Fe3O4 MNPs), coating of silica on Fe3O4 MNPs (Fe3O4@SiO2) and incorporation of sulfonic acid as a functional group on the surface of Fe3O4@SiO2 nanoparticles (Fe3O4@SiO2@SO3H). The properties of the prepared magnetic nanoparticles were characterized using transmission electron microscopy, infrared spectroscopy, vibrating sample magnetometry, X‐ray diffraction and thermogravimetric analysis. Finally, the applicability of the synthesized magnetic nanoparticles was tested as a heterogeneous solid acid nanocatalyst for one‐pot synthesis of diindolyloxindole derivatives in aqueous medium. Oxindole derivatives were produced by the coupling of indole and isatin compounds with good to high yields (60–98%). Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
16.
This work provides an insight into the effect of incorporating of magnetite nanoparticles on the rheology of fluids. In this respect, polymer-stabilized magnetite nanoparticles were obtained using sodium salt of poly (2-acrylamido-2-methylpropanesulfonate (PAMPS-Na). Monodisperse polymer coated magnetite nanoparticles Fe3O4/poly(styrene-AMPS) copolymer nanoparticles with diameters of 50–300 nm were prepared by radical polymerization in the presence of a ferrofluid coated with PAMPS-Na. The magnetic nanoparticles were easily separated in a magnetic field. The structure of the obtained magnetic nanoparticles was characterized by Fourier transform infrared spectroscopy (FTIR). The morphology and size of the magnetic nanoparticles were determined by transmission electron microscopy (TEM). FTIR and TEM revealed that the Fe3O4 nanoparticles were incorporated into the shells of poly(styrene-AMPS). Aqueous dispersed solutions of a charged hydrophobically modified Fe3O4/poly(styrene-AMPS) copolymer nanoparticles exhibit high viscosities even at low polymer concentrations (0.1 wt %), which is an interesting feature in connection with enhanced oil recovery. Effects of temperature and addition of sodium chloride on the viscosity properties of a semidilute dispersed solution of Fe3O4/poly(styrene-AMPS) copolymer nanoparticles are examined. The results indicated that Fe3O4/poly(styrene-AMPS) copolymer nanoparticles disclose strong interactions between magnetite and coated polymers of both PAMPS-Na and styrene-AMPS copolymers. 相似文献
17.
Rod-like assembled magnetite (Fe3O4) nanoparticles (NPs) were successfully synthesized in a one-pot process using a polysiloxane template derived from a dialkoxysilane. The assembly was constructed using the thiol-ene click reaction between thiol groups on the polysiloxane chain and allyl groups on Fe3O4 NPs. The thiol-containing polysiloxane chain and the allyl-containing Fe3O4 NPs were synthesized by the hydrolysis–condensation of 3-mercaptopropyl(dimethoxy)methylsilane and iron (III) allylacetylacetonate, respectively. Fe3O4 NPs of around 5 nm were uniformly dispersed on the siloxane rods and exhibited neither remanent magnetization nor coercivity. A fluid containing a dispersion of rod-like assembled Fe3O4 NPs showed yield stress even without the application of an external magnetic field, whereas spherical Fe3O4 NPs exhibited no yield stress. The rod-like assembled Fe3O4 NPs on anisotropic siloxane clearly exhibited typical magnetorheological behavior. 相似文献
18.
Synthesis of pH‐responsive magnetic yolk–shell nanoparticles: A comparison between conventional etching and new deswelling approaches
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Iron oxide (Fe3O4) magnetic nanoparticles as movable cores were used to synthesize yolk–shell nanoparticles with pH‐responsive shell composed of ethylene glycol dimethacrylate (EGDMA)‐crosslinked poly(acrylic acid) (PAA) via two different routes. In the first more common route, Fe3O4 nanoparticles were coated with silica layer via the Stöber process to yield Fe3O4@SiO2 core–shell nanoparticles, subsequently used as seeds in the distillation precipitation copolymerization of AA and EGDMA to yield Fe3O4@SiO2@P(AA‐EGDMA). The silica layer was selectively removed through alkali etching to yield Fe3O4@air@P(AA‐EGDMA). In the second route, Fe3O4 nanoparticles without any stabilization were used as seeds in the distillation precipitation copolymerization of AA and EGDMA to yield Fe3O4@P(AA‐EGDMA) core–shell nanoparticles. The nanoparticles were subsequently dispersed in acidic medium of pH = 2. Yolk–shell Fe3O4@air@P(AA‐EGDMA) nanoparticles were formed through deswelling of crosslinked PAA because of protonation of carboxyl groups at low pH values. Various techniques were utilized to investigate the characteristics of the synthesized core–shell nanoparticles. Formation of yolk–shell nanostructure was observed for both synthesis routes, namely etching of silica layer and deswelling approaches, from vibrating sample magnetometry and transmission electron microscopy results. Both types of nanoparticles showed pH‐responsive behaviour, i.e. decrease in absorption with increase in pH, as examined using UV–visible spectroscopy. 相似文献
19.
Xiao-Li Dong Xiao-Yan Mou Hong-Chao Ma Xin-Xin Zhang Xiu-Fang Zhang Wen-Jie Sun Chun Ma Mang Xue 《Journal of Sol-Gel Science and Technology》2013,66(2):231-237
The CdS modified TiO2/Fe3O4 photocatalysts were prepared by sol–gel and immersion methods. The morphological, structural and optical properties of as-prepared samples were characterized by X-ray diffraction (XRD), UV–Vis absorption spectra, X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). The TEM observation showed that the surface of magnetite particles (Fe3O4) were coated by CdS–TiO2 layer as loose clusters, and average diameter of composites particles was about 250 nm. UV–Vis absorption spectra indicated that CdS–TiO2/Fe3O4 composites had pronounced red-shift compared with that of TiO2/Fe3O4. The CdS–TiO2/Fe3O4 composites exhibit higher photocatalytic activity than pure TiO2 and TiO2/Fe3O4 for the degradation of Reactive Brilliant Red X-3B dye (X-3B) aqueous solution under simulated sunlight, and the optimum content of CdS is 1.0 % (mol ratio of CdS to TiO2). In addition, a gradual loss of photocatalytic activity can be observed in reusability test of CdS–TiO2/Fe3O4 composites, and degradation of X-3B reached still to 78.9 % after five runs. 相似文献
20.
Xifang Chen Yue Zhou Hongwen Han Xiaoyu Wang Lei Zhou Zao Yi Zhenjin Fu Xianwen Wu Gongfa Li Liangcai Zeng 《Materials Today Chemistry》2021
Core–shell Fe3O4@C magnetic nanoparticles which are of great interest for research have a widely applied prospect. However, people know little about the optical and magnetic properties of the small-size Fe3O4@C nanoparticles due to the difficulty of uniformly coating small size Fe3O4 nanoparticles. In this paper, the influence of carbon shell coating on the optical and magnetic properties of small size Fe3O4 nanoparticles was presented. Carbon coating can strengthen the absorption intensity in the UV–visible light region through the introduction of oxygen defects on the surface of the nanoparticles by nitric acid treatment. Fe3O4 and Fe3O4@C nanoparticles both display typical superparamagnetic behavior in the high-temperature regime and a blocked state at low temperature from hysteresis loop, zero-field cooled and field cooled curves. Carbon coating reduce the surface uniaxial anisotropy, thus the average blocking temperature <TB> decreases from 59 K of Fe3O4 nanoparticles to 50 K of Fe3O4@C nanoparticles. 相似文献