共查询到20条相似文献,搜索用时 93 毫秒
1.
Mir Mohammad Alavi Nikje Sahebeh Tamaddoni Moghaddam Maede Noruzian Mohammad Amin Farahmand Nejad Keyvan Shabani Moslem Haghshenas Saeed Shakhesi 《Colloid and polymer science》2014,292(3):627-633
Novel magnetic polyurethane flexible foam nanocomposites were synthesized by incorporation of aminopropyltriethoxysilane (APTS) functionalized magnetite nanoparticles (MNPs) via one-shot method. The functionalized MNPs (Fe3O4@APTS) were synthesized by co-precipitation of the Fe2+ and Fe3+ with NH4OH and further functionalization with APTS onto the surface of MNPs by sol–gel method. The magnetic core-shell NPs were used up to 3.0 % in the foam formulation and the magnetic nanocomposites prepared successfully. The results of thermogravimetric analysis (TGA) showed an increasing in thermal stability of polyurethane nanocomposite foam at initial, 5 and 10 %, and maximum thermal decomposition temperatures by incorporation of Fe3O4@APTS. In addition SEM images revealed the uniformity of the foam structures and decreasing in pore sizes. Furthermore, VSM result showed super paramagnetic behavior for Fe3O4@APTS-PU nanocomposites. 相似文献
2.
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
3.
Fe3O4 nanoparticles (NPs) were prepared by the co‐precipitation of Fe3+ and Fe2+ with ammonium hydroxide, and were modified by four different surfactants. The modified Fe3O4 NPs were characterized by Fourier transform infrared spectroscopy, X‐ray powder diffraction, transmission electron microscopy and vibrating sample magnetometer. Then, the modified Fe3O4 NPs were dispersed in ethiodized‐oil by mechanical agitation and ultrasonic vibration to obtain stable Fe3O4/ethiodized‐oil magnetic fluids (MFs). The magnetic properties and rheological properties of the MFs were measured using a Gouy magnetic balance and a rotational rheometer, respectively. The saturation magnetization of the Fe3O4 modified by oleic acid was 52.1 emu/g. Furthermore, the result showed that the inductive heating effect of oleic acid stabilized Fe3O4/ethiodized‐oil MF was remarkable and it only took 650 s for the temperature rising from 25°C to 65°C. The specific absorption rate of the MF was 50.16 W/(g of Fe). It had a potential application in arterial embolization hyperthermia. 相似文献
4.
We report a facile method to synthesize dispersed Fe3O4@C nanoparticles(NPs). Fe3O4 NPs were firstly prepared via the high temperature diol thermal decomposition method. Fe3O4@C NPs were fabricated using glucose as a carbon source by hydrothermal process. The obtained products were characterized by X-ray diffraction(XRD), transmission electron microscopy(TEM), vibrating sample magnetometer(VSM) and Raman spectra. The results indicate that the original shapes and magnetic property of Fe3O4 NPs can be well preserved. The magnetic particles are well dispersed in the carbon matrix. This strategy would provide an efficient approach for existing applications in Li-ion batteries and drug delivery. Meanwhile, it offers the raw materials to assemble future functional nanometer and micrometer superstructures. 相似文献
5.
Monodispersed cobalt nanoparticles (NPs) with controllable size (8–14 nm) have been synthesized using thermal decomposition of dicobaltoctacarbonyl in organic solvent. The as-synthesized high magnetic moment (125 emu/g) Co NPs are dispersible in various organic solvents, and can be easily transferred into aqueous phase by surface modification using phospholipids. However, the modified hydrophilic Co NPs are not stable as they are quickly oxidized, agglomerated in buffer. Co NPs are stabilized by coating the MFe2O4 (M=Fe, Mn) ferrite shell. Core/shell structured bimagnetic Co/MFe2O4 nanocomposites are prepared with tunable shell thickness (1–5 nm). The Co/MFe2O4 nanocomposites retain the high magnetic moment density from the Co core, while gaining chemical and magnetic stability from the ferrite shell. Compared to Co NPs, the nanocomposites show much enhanced stability in buffer solution at elevated temperatures, making them promising for biomedical applications. 相似文献
6.
Dr. Jiwei Liu Junjie Xu Prof. Renchao Che Huajun Chen Mengmei Liu Zhengwang Liu 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(21):6746-6752
A facile and efficient strategy for the synthesis of hierarchical yolk–shell microspheres with magnetic Fe3O4 cores and dielectric TiO2 shells has been developed. Various Fe3O4@TiO2 yolk–shell microspheres with different core sizes, interstitial void volumes, and shell thicknesses have been successfully synthesized by controlling the synthetic parameters. Moreover, the microwave absorption properties of these yolk–shell microspheres, such as the complex permittivity and permeability, were investigated. The electromagnetic data demonstrate that the as‐synthesized Fe3O4@TiO2 yolk–shell microspheres exhibit significantly enhanced microwave absorption properties compared with pure Fe3O4 and our previously reported Fe3O4@TiO2 core–shell microspheres, which may result from the unique yolk–shell structure with a large surface area and high porosity, as well as synergistic effects between the functional Fe3O4 cores and TiO2 shells. 相似文献
7.
Ahmed El Nemr Mohamed A. Hassaan Marwa R. Elkatory Safaa Ragab Antonio Pantaleo 《Molecules (Basel, Switzerland)》2021,26(16)
In this work, different pretreatment methods for algae proved to be very effective in improving cell wall dissociation for biogas production. In this study, the Ulva intestinalis Linnaeus (U. intestinalis) has been exposed to individual pretreatments of (ultrasonic, ozone, microwave, and green synthesized Fe3O4) and in a combination of the first three mentioned pretreatments methods with magnetite (Fe3O4) NPs, (ultrasonic-Fe3O4, ozone-Fe3O4 and microwave-Fe3O4) in different treatment times. Moreover, the green synthesized Fe3O4 NPs has been confirmed by FTIR, TEM, XRD, SEM, EDEX, PSA and BET. The maximum biogas production of 179 and 206 mL/g VS have been attained when U. intestinalis has been treated with ultrasonic only and when combined microwave with Fe3O4 respectively, where sediment were used as inoculum in all pretreatments. From the obtained results, green Fe3O4 NPs enhanced the microwave (MW) treatment to produce a higher biogas yield (206 mL/g VS) when compared with individual MW (84 mL/g VS). The modified Gompertz model (R2 = 0.996 was appropriate model to match the calculated biogas production and could be used more practically to distinguish the kinetics of the anaerobic digestion (AD) period. The assessment of XRD, SEM and FTIR discovered the influence of different treatment techniques on the cell wall structure of U. intestinalis. 相似文献
8.
《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(28):8222-8226
Janus nanoparticles (JNPs) offer unique features, including the precisely controlled distribution of compositions, surface charges, dipole moments, modular and combined functionalities, which enable excellent applications that are unavailable to their symmetrical counterparts. Assemblies of NPs exhibit coupled optical, electronic and magnetic properties that are different from single NPs. Herein, we report a new class of double‐layered plasmonic–magnetic vesicle assembled from Janus amphiphilic Au‐Fe3O4 NPs grafted with polymer brushes of different hydrophilicity on Au and Fe3O4 surfaces separately. Like liposomes, the vesicle shell is composed of two layers of Au‐Fe3O4 NPs in opposite direction, and the orientation of Au or Fe3O4 in the shell can be well controlled by exploiting the amphiphilic property of the two types of polymers. 相似文献
9.
A new type of metal-oxide-coated magnetic nanoparticles (NPs)—tantalum-oxide-coated magnetic iron oxide (Fe3O4@Ta2O5) NPs—which are used as affinity probes for selectively trapping phosphopeptides from complex samples, is demonstrated in
this study. In this approach, phosphopeptide enrichment was achieved by incubating the NPs with sample solutions under microwave
heating within 1 min. The NP–target species conjugates were readily isolated from samples by magnetic separation followed
by matrix-assisted laser desorption/ionization (MALDI) mass spectrometric analysis. When using human serum as the sample,
phosphorylated fibrinopeptide-A-derived ions are the only ions observed in the MALDI mass spectra after enrichment by the
Fe3O4@Ta2O5 NPs. Furthermore, only phosphopeptides appear in the MALDI mass spectra after using the affinity probes to selectively trap
target species from the tryptic digest of a cell lysate and milk sample. The results demonstrated that the Fe3O4@Ta2O5 NPs have the capability of selectively trapping phosphorylated peptides from complex samples. The detection limit of this
approach for a phosphopeptide (FQpSEEQQQTEDELQDK) was ~10 fmol.
Figure For the first time, tantalum oxide-coated magnetic iron oxide (Fe3O4@Ta2O5) NPs were demonstrated as suitable affinity-probes for selectively trapping phosphopeptides from complex samples. To shorten
the analysis time, phosphopeptide enrichment was achieved by incubating the NPs with sample solutions under microwave-heating
within 1 min. MALDI MS was employed for characterization of the species trapped by the NPs. 相似文献
10.
Supercritical Carbon Dioxide Assisted Deposition of Fe3O4 Nanoparticles on Hierarchical Porous Carbon and Their Lithium‐Storage Performance 下载免费PDF全文
Dr. Lingyan Wang Dr. Linhai Zhuo Dr. Chao Zhang Prof. Dr. Fengyu Zhao 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(15):4308-4315
A composite of highly dispersed Fe3O4 nanoparticles (NPs) anchored in three‐dimensional hierarchical porous carbon networks (Fe3O4/3DHPC) as an anode material for lithium‐ion batteries (LIBs) was prepared by means of a deposition technique assisted by a supercritical carbon dioxide (scCO2)‐expanded ethanol solution. The as‐synthesized Fe3O4/3DHPC composite exhibits a bimodal porous 3D architecture with mutually connected 3.7 nm mesopores defined in the macroporous wall on which a layer of small and uniform Fe3O4 NPs was closely coated. As an anode material for LIBs, the Fe3O4/3DHPC composite with 79 wt % Fe3O4 (Fe3O4/3DHPC‐79) delivered a high reversible capacity of 1462 mA h g?1 after 100 cycles at a current density of 100 mA g?1, and maintained good high‐rate performance (728, 507, and 239 mA h g?1 at 1, 2, and 5 C, respectively). Moreover, it showed excellent long‐term cycling performance at high current densities, 1 and 2 A g?1. The enhanced lithium‐storage behavior can be attributed to the synergistic effect of the porous support and the homogeneous Fe3O4 NPs. More importantly, this straightforward, highly efficient, and green synthetic route will definitely enrich the methodologies for the fabrication of carbon‐based transition‐metal oxide composites, and provide great potential materials for additional applications in supercapacitors, sensors, and catalyses. 相似文献
11.
Dborah De Masi Juan M. Asensio Pier‐Francesco Fazzini Lise‐Marie Lacroix Bruno Chaudret 《Angewandte Chemie (International ed. in English)》2020,59(15):6187-6191
Induction heating of magnetic nanoparticles (NPs) is a method to activate heterogeneous catalytic reactions. It requires nano‐objects displaying high heating power and excellent catalytic activity. Here, using a surface engineering approach, bimetallic NPs are used for magnetically induced CO2 methanation, acting both as heating agent and catalyst. The organometallic synthesis of Fe30Ni70 NPs displaying high heating powers at low magnetic field amplitudes is described. The NPs are active but only slightly selective for CH4 after deposition on SiRAlOx owing to an iron‐rich shell (25 mL min?1, 25 mT, 300 kHz, conversion 71 %, methane selectivity 65 %). Proper surface engineering consisting of depositing a thin Ni layer leads to Fe30Ni70@Ni NPs displaying a very high activity for CO2 hydrogenation and a full selectivity. A quantitative yield in methane is obtained at low magnetic field and mild conditions (25 mL min?1, 19 mT, 300 kHz, conversion 100 %, methane selectivity 100 %). 相似文献
12.
Altangerel Amarjargal Leonard D. Tijing Chan-Hee Park Ik-Tae Im Cheol Sang Kim 《European Polymer Journal》2013
A facile method of fabricating novel heat-generating membranes composed of electrospun polyurethane (PU) nanofibers decorated with superparamagnetic iron oxide nanoparticles (NPs) is reported. Electrospinning was used to produce polymeric nanofibrous matrix, whereas polyol immersion technique allowed in situ assembly of well-dispersed Fe3O4 NPs on the nanofibrous membranes without any surfactant, and without sensitizing and stabilizing reagent. The assembly phenomena can be explained by the hydrogen-bonding interactions between the amide groups in the PU matrix and the hydroxyl groups capped on the surface of the Fe3O4 NPs. The prepared nanocomposite fibers showed acceptable magnetization value of 33.12 emu/g, after measuring the magnetic hysteresis loops using SQUID. Moreover, the inductive heating property of electrospun magnetic nanofibrous membranes under an alternating current (AC) magnetic field was investigated. We observed a progressive increase in the heating rate with the increase in the amount of magnetic Fe3O4 NPs in/on the membranes. The present electrospun magnetic nanofibrous membrane may be a potential candidate as a novel heat-generating substrate for localized hyperthermia cancer therapy. 相似文献
13.
The heterostructured Ag nanoparticles decorated Fe3O4 Glutathione (Fe3O4‐Glu‐Ag) nanoparticles (NPs) were synthesized by sonicating glutathione (Glu) with magnetite and further surface immobilization of silver NPs on it. The ensuing magnetic nano catalyst is well characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), powder X‐ray diffraction (PXRD), thermogravimetric analysis (TGA). The prepared Fe3O4‐Glu‐Ag nanoparticles have proved to be an efficient and recyclable nanocatalyst with low catalyst loading for the reduction of nitroarenes and heteronitroarenes to respective amines in the presence of NaBH4 using water as a green solvent which could be easily separated at the end of a reaction using an external magnet and can be recycled up to 5 runs without any significant loss in catalytic activity. Gram scale study for the reduction of 4‐NP has also being carried out successfully and it has been observed that this method can serve as an efficient protocol for reduction of nitroarenes on industrial level. 相似文献
14.
Peapod‐Type Nanocomposites through the In Situ Growth of Gold Nanoparticles within Preformed Hexaniobate Nanoscrolls 下载免费PDF全文
Dr. Shiva Adireddy Cecilia E. Carbo Taha Rostamzadeh Dr. Jose M. Vargas Prof. Leonard Spinu Prof. John B. Wiley 《Angewandte Chemie (International ed. in English)》2014,53(18):4614-4617
A facile in situ method to grow Au nanoparticles (NPs) in hexaniobate nanoscrolls is applied to the formation of plasmonic Au@hexaniobate and bifunctional plasmonic‐magnetic Au‐Fe3O4@hexaniobate nanopeapods (NPPs). Utilizing a solvothermal treatment, rigid multiwalled hexaniobate nanoscrolls and partially filled Fe3O4@hexaniobate NPPs were first fabricated. These nanostructures were then used as templates for the controlled in situ growth of Au NPs. The resulting peapod structures exhibited high filling fractions and long‐range uniformity. Optical measurements showed a progressive red shift in plasmonic behavior between Au NPs, Au NPPs, and Au‐Fe3O4 NPPs; magnetic studies found that the addition of gold in the Fe3O4@hexaniobate NPPs reduced interparticle coupling effects. The development of this approach allows for the routine bulk preparation of noble‐metal‐containing bifunctional nanopeapod materials. 相似文献
15.
Simple Surfactant Concentration‐Dependent Shape Control of Polyhedral Fe3O4 Nanoparticles and Their Magnetic Properties 下载免费PDF全文
Dr. Wanyin Ge Dr. Ryota Sato Dr. Hsin‐Lun Wu Prof.Dr. Toshiharu Teranishi 《Chemphyschem》2015,16(15):3200-3205
The shape and size of monodisperse Fe3O4 nanoparticles (NPs) are controlled using a chemical solution synthesis in the presence of the surfactant cetylpyridinium chloride (CPC). Cubic Fe3O4 NPs surrounded by six {100} planes are obtained in the absence of CPC. Increasing the CPC content during synthesis causes the shape of the resulting Fe3O4 NPs to change from cubic to truncated cubic, cuboctahedral, truncated octahedral, and finally octahedral. During this evolution, the predominantly exposed planes of the Fe3O4 NPs vary from {100} to {111}. The shape control results from the synergistic effect of the pyridinium cations, chloride anions, and long‐chain alkyl groups of CPC, which is confirmed by comparison with NPs synthesized in the presence of various related cationic surfactants. The size of the cubic Fe3O4 NPs can be tuned from 50 to 200 nm, by changing the concentration of oleic acid in the reaction solution. The Fe3O4 NPs exhibit shape‐dependent saturation magnetization, remanent magnetization, and coercivity. 相似文献
16.
A facile solid‐phase extraction (SPE) method based on bare Fe3O4 magnetic nanoparticles (Fe3O4 NPs) was developed to capture cinnamic acid (CA) from a well‐known traditional Chinese medicine, Ramulus cinnamomi, for high performance liquid chromatography (HPLC) analysis. The as‐prepared Fe3O4 NPs were characterized via Fourier transform infrared spectroscopy (FTIR), X‐ray diffraction (XRD), transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM). Several parameters that influence CA extraction rate, such as the amount of Fe3O4 NPs, shaking time, methanol content, eluent pH, and elution time, were investigated. The experimental results show that the CA extraction was 86.9 % at optimal condition, and the mass yield of CA extraction was found to be 0.00021 %. This study demonstrates that the developed CA extraction method is simple, cheap and environmentally friendly. Therefore, the proposed method has a potential for CA separation and purification from complex biological samples. 相似文献
17.
《应用有机金属化学》2017,31(10)
Green tea extract having many phenolic hydroxyl and carbonyl functional groups in its molecular framework can be used in the modification of Fe3O4 nanoparticles. Moreover, the feasibility of complexation of polyphenols with silver ions in aqueous solution can improve the surface properties and capacity of the Fe3O4@green tea extract nanoparticles (Fe3O4@GTE NPs) for sorption and reduction of silver ions. Therefore, the novel Fe3O4@GTE NPs nano‐sorbent has potential ability as both reducing and stabilizing agent for immobilization of silver nanoparticles to make a novel magnetic silver nanocatalyst (Fe3O4@GTE/Ag NPs). Inductively coupled plasma analysis, transmission and scanning electron microscopies, energy‐dispersive X‐ray and Fourier transform infrared spectroscopies, and vibrating sample magnetometry were used to characterize the catalyst. Fe3O4@GTE/Ag NPs shows high catalytic activity as a recyclable nanocatalyst for the reduction of 4‐nitrophenol at room temperature. 相似文献
18.
Polyethersulfone (PES) and poly(1‐vinylpyrrolidone) (PVP) were used to prepare ultrafiltration membranes with grafted Fe3O4 magnetic nanoparticles (PVP‐g‐Fe3O4@SiO2). The structure of synthesized PVP‐g‐Fe3O4@SiO2 was confirmed by FT‐IR and SEM analysis. Physical properties of blend membranes such as thermal resistance, Tensile strength, water uptake, and hydrophilicity were also investigated. Blended membranes of PES/PVP‐g‐Fe3O4@SiO2 have exhibited higher thermal resistance due to increasing the modified nanoparticle content. The hydrophilicity of the synthesized PES/PVP‐g‐Fe3O4@SiO2 membranes also improved by increasing the PVP‐g‐Fe3O4@SiO2 content. As expected, increasing the hydrophilicity of blended membrane, caused enhancement of fouling resistance in membranes. Results showed that the content of PVP‐g‐Fe3O4@SiO2 has different effects on the properties of synthesized composite membranes. Despite increasing the content of PVP‐g‐Fe3O4@SiO2 has a negative effect on elongation, positive effects on maximum stress was observed. Moreover, the water uptake of synthesized membranes was significantly enhanced in comparison to other similar studies. 相似文献
19.
Covalent bonding of magnetic Fe3O4 nanoparticles to aminopropyl‐functionalized magnesium phyllosilicate clay: Synthesis and cytotoxic potential investigation 下载免费PDF全文
Hasan Nasrabadi Zahra Amirghofran Ahmadreza Esmaeilbeig Mehrangiz Bahrami S. Jafar Hoseini 《应用有机金属化学》2018,32(2)
Stable water dispersion of Fe3O4 magnetic nanoparticles (NPs) were successfully synthesized by using 3‐glycidoxypropyltrimethoxysilane (GPTMS) and Mg‐phyllo (organo) silicate known as aminoclay (AC) containing pendant amino groups with the approximate composition (R8Si8Mg6O16(OH)4, R = CH2CH2CH2NH2). The Fe3O4‐GPTMS magnetic NPs with an epoxy functional group are suitable for forming a covalent bond with the amine group of aminoclay in an epoxy ring opening reaction. Appropriate Fe3O4‐GPTMS‐aminoclay (FG‐AC) magnetic composite are promising carriers for the targeting and delivery of platinum‐based anticancer drugs. Analysis of the cytotoxicity of the nanostructures on a K562 leukemia cell line using a colorimetery assay shows that both the FG‐AC and cis‐platin/FG‐AC magnetic composite were biocompatible. The nanostructures characterizations were investigated by Fourier transform infrared spectroscopy, X‐ray diffraction, transmission electron microscopy and energy dispersive analysis of X‐ray techniques. Magnetic measurement revealed that the saturated magnetization of the FG‐AC nanocomposite reached 7.6 emu/g and showed the characteristics of magnetism. 相似文献