Sonochemical synthesis of stable hydrosol of Fe3O4 nanoparticles

The sonolysis of an aqueous solution of Fe(CO)(5) in the presence of sodium dodecyl sulfate leads to the formation of a stable hydrosol of amorphous Fe(3)O(4) nanoparticles. The amorphicity of iron oxide nanoparticles was determined by X-ray diffraction and differential scanning calorimetry. The nanoparticles were characterized by elemental analysis, EDX, transmission electron microscopy, dynamic light scattering, Raman spectroscopy, XPS, and spot test.     

Effects of magnetite nanoparticles on the thermorheological properties of carrageenan hydrogels

The influence of magnetite (Fe(3)O(4)) nanoparticles on the rheological properties of kappa-, iota- and lambda-carrageenan gels has been investigated. Small amplitude oscillatory shear measurements were performed to study the effect of the presence of Fe(3)O(4) nanoparticles with particle sizes of ca. 10 nm on the gel properties, as a function of carrageenan type, carrageenan concentration and magnetite load. The formation of Fe(3)O(4) nanoparticles on the presence of biopolymer was observed to promote the gelation process and lead to stronger gels as indicated by an increase in the gel viscoelastic moduli and of the gelation temperature. This effect was more marked for kappa-carrageenan than for iota- and lambda-carrageenan and has been proposed to depend not only on Fe(3)O(4) concentration but also on the concentration of potassium ions. A mechanism based on the combined effect of Fe(3)O(4) nanoparticles and potassium ions was suggested, involving the adsorption of potassium ions on the negatively charged surface of the Fe(3)O(4) nanoparticles, thus leading to an increase of the potassium ion concentration within the "carrageenan cages" containing the magnetite. This would, therefore, promote more extensive biopolymer helical aggregation, thus resulting in the formation of a stronger kappa-carrageenan gel in the presence of Fe(3)O(4), as observed. Since iota- and lambda-carrageenan gels are known to be less sensitive to potassium ions concentration, the effect of precipitating Fe(3)O(4) within these biopolymers is reduced.     

Fe3O4 nanoparticle-integrated graphene sheets for high-performance half and full lithium ion cells

We synthesized Fe(3)O(4) nanoparticle/reduced graphene oxide (RGO-Fe(3)O(4)) nanocomposites and evaluated their performance as anodes in both half and full coin cells. The nanocomposites were synthesized through a chemical co-precipitation of Fe(2+) and Fe(3+) in the presence of graphene oxides within an alkaline solution and a subsequent high-temperature reduction reaction in argon (Ar) environment. The morphology and microstructures of the fabricated RGO-Fe(3)O(4) nanocomposites were characterized using various techniques. The results indicated that the Fe(3)O(4) nanoparticles had relatively homogeneous dispersions on the RGO sheet surfaces. These as-synthesized RGO-Fe(3)O(4) nanocomposites were used as anodes for both half and full lithium-ion cells. Electrochemical measurement results exhibit a high reversible capacity which is about two and a half times higher than that of graphite-based anodes at a 0.05C rate, and an enhanced reversible capacity of about 200 mAh g(-1) even at a high charge/discharge rate of 10C (9260 mA g(-1)) in half cells. Most important of all, these fabricated novel nanostructures also show exceptional capacity retention with the assembled RGO-Fe(3)O(4)/LiNi(1/3)Mn(1/3)Co(1/3)O(2) full cell at different C rates. This outstanding electrochemical behavior can be attributed to the unique microstructure, morphology, texture, surface properties of the nanocomposites, and combinative effects from the different chemical composition in the nanocomposites.     

External magnetic field-induced mesoscopic organization of Fe3O4 pyramids and carbon sheets

The current investigation is centered on the thermal decomposition of iron(II) acetyl acetonate, Fe(C5H7O2)2, in a closed cell at 700 degrees C, which is conducted under a magnetic field (MF) of 10 T. The product is compared with a similar reaction that was carried out without a MF. This article shows how the reaction without a MF produces spherical Fe3O4 particles coated with carbon. The same reaction in the presence of a 10 T MF causes the rejection of the carbon from the surface of pyramid-shaped Fe3O4 particles, increases the Fe3O4 particle diameter, forms separate carbon particles, and leads to the formation of an anisotropic (long cigarlike) orientation of Fe3O4 pyramids and C sheets. The macroscopic orientation of Fe3O4 pyramids+C sheets is stable even after the removal of an external MF. The suggested process can be used to fabricate large arrays of uniform wires comprised of some magnetic nanoparticles, and to improve the magnetic properties of nanoscale magnetic materials. The probable mechanism is developed for the growth and assembly behavior of magnetic Fe3O4 pyramids+C sheets under an external MF. The effect of an applied MF to synthesize morphologically different, but structurally the same, products with mesoscopic organization is the key theme of the present paper.     

Preparation and mechanism of Fe_3O_4/Au core/shell super-paramagnetic microspheres

In the presence of Fe3O4 nano-particles, a new type of super-paramagnetic Fe3O4/Au microspheres with core/shell structures was prepared by reduction of Au3+ with hydroxylamine. The formation mechanism of the core/shell microspheres was studied in some detail. It was shown that the formation of the complex microspheres can be divided into two periods, that is, surface reaction-controlled process and diffusion-controlled process. The relative time lasted by either process depends upon the amount of Fe3O4 added and the initial concentration of Au3+. XPS analysis revealed that along with increasing in coating amount, the strength of the characteristic peaks of Au increased, and the Auger peaks of Fe weakened and even disappeared. Size distribution analysis showed that the core/shell microspheres are of an average diameter of 180 nm, a little bit larger than those before coating.     

Scandium ion-enhanced oxidative dimerization and N-demethylation of N,N-dimethylanilines by a non-heme iron(IV)-oxo complex

Oxidative dimerization of N,N-dimethylaniline (DMA) occurs with a nonheme iron(IV)-oxo complex, [Fe(IV)(O)(N4Py)](2+) (N4Py = N,N-bis(2-pyridylmethyl)-N-bis(2-pyridyl)methylamine), to yield the corresponding dimer, tetramethylbenzidine (TMB), in acetonitrile. The rate of the oxidative dimerization of DMA by [Fe(IV)(O)(N4Py)](2+) is markedly enhanced by the presence of scandium triflate, Sc(OTf)(3) (OTf = CF(3)SO(3)(-)), when TMB is further oxidized to the radical cation (TMB(?+)). In contrast, we have observed the oxidative N-demethylation with para-substituted DMA substrates, since the position of the C-C bond formation to yield the dimer is blocked. The rate of the oxidative N-demethylation of para-substituted DMA by [Fe(IV)(O)(N4Py)](2+) is also markedly enhanced by the presence of Sc(OTf)(3). In the case of para-substituted DMA derivatives with electron-donating substituents, radical cations of DMA derivatives are initially formed by Sc(3+) ion-coupled electron transfer from DMA derivatives to [Fe(IV)(O)(N4Py)](2+), giving demethylated products. Binding of Sc(3+) to [Fe(IV)(O)(N4Py)](2+) enhances the Sc(3+) ion-coupled electron transfer from DMA derivatives to [Fe(IV)(O)(N4Py)](2+), whereas binding of Sc(3+) to DMA derivatives retards the electron-transfer reaction. The complicated kinetics of the Sc(3+) ion-coupled electron transfer from DMA derivatives to [Fe(IV)(O)(N4Py)](2+) are analyzed by competition between binding of Sc(3+) to DMA derivatives and to [Fe(IV)(O)(N4Py)](2+). The binding constants of Sc(3+) to DMA derivatives increase with the increase of the electron-donating ability of the para-substituent. The rate constants of Sc(3+) ion-coupled electron transfer from DMA derivatives to [Fe(IV)(O)(N4Py)](2+), which are estimated from the binding constants of Sc(3+) to DMA derivatives, agree well with those predicted from the driving force dependence of the rate constants of Sc(3+) ion-coupled electron transfer from one-electron reductants to [Fe(IV)(O)(N4Py)](2+). Thus, oxidative dimerization of DMA and N-demethylation of para-substituted DMA derivatives proceed via Sc(3+) ion-coupled electron transfer from DMA derivatives to [Fe(IV)(O)(N4Py)](2+).     

磁场诱导沉淀聚合制备一维Fe3O4/P（MAA-DVB）纳米链

采用溶剂热法制备了单分散Fe3O4纳米粒子,以甲基丙烯酸（MAA）和二乙烯基苯（DVB）为聚合单体,在沉淀聚合过程中通过磁场诱导自组装制备了一维高磁响应性永久连接的Fe3O4/P（MAA-DVB）纳米链.采用扫描电镜（SEM）,透射电镜（TEM）,X射线衍射仪（XRD）,热重分析（TGA）及振动样品磁强计（VSM）等对其形貌、磁含量和磁响应性等进行了分析表征.结果表明,该法制备的一维Fe3O4/P（MAA-DVB）纳米链的磁含量为91%时,其比饱和磁化强度为72emu/g.在外磁场存在条件下,一维Fe3O4/P（MAA-DVB）纳米链将按外界磁场的方向取向.此外,每个豆荚内的Fe3O4纳米粒子规则的排列在一条线上,并通过P（MAA-DVB）聚合物使其均匀分布.     

Mechanistic studies on oxidation of L-ascorbic acid by an oxo-bridged diiron complex in aqueous acidic media

[Fe2(micro-O)(phen)4(H2O)2]4+ (1) (Fig. 1, phen = 1,10-phenanthroline) equilibrates with [Fe2(micro-O)(phen)4(H2O)(OH)]3+ (2) and [Fe2(micro-O)(phen)4(OH)2]2+ (3) in aqueous solution in the presence of excess phen, where no phen-releasing equilibria from 1, 2 and 3 exist. 1 quantitatively oxidizes ascorbic acid (H2A) to dehydroascorbic acid (A) in the pH range 3.00-5.50 in the presence of excess phen, which buffers the reaction within 0.05 pH units and ensures complete formation of end iron product ferroin, [Fe(phen)3]2+. The reactive species are 1, 2 and HA- and the reaction proceeds through an initial 1 : 1 inner-sphere adduct formation between 1 and 2 with HA-, followed by a rate limiting outer-sphere one electron one proton (electroprotic) transfer from a second HA- to the ascorbate-unbound iron(III).     

La2O3对费-托合成沉淀铁催化剂的影响

制备了一系列不同La2O3含量(100Fe/2.8Si/nLa,n=0,0.5,1,2,4,原子比)的沉淀铁费-托合成催化剂,通过原位X射线衍射、一氧化碳程序升温还原和N2吸附-脱附等手段对催化剂进行了表征.催化剂费-托反应评价在固定床反应器中进行.结果表明,少量La2O3助剂(La/Fe≤0.01,原子比)的加入显著降低了Fe2O3颗粒大小,增加了催化剂的比表面积和分散度,有利于碳化铁的形成,从而导致费-托合成催化活性的提高.随着La2O3含量的进一步增加(La/Fe≥0.02),催化剂表面大量La2O3的覆盖和LaFeO3化合物的形成降低了铁碳化物的形成,反应活性反而降低.因此,最适宜的La2O3含量为La/Fe=0.01.La2O3的加入提高了甲烷的选择性,抑制了C5+碳氢化合物的形成.     

Antimony dispersion and phase evolution in the Sb2O3-Fe2O3 system

This paper studies the antimony spreading and segregation that occurred along with the oxidation and solid-state reactions in the Fe2O3-Sb2O3 system. XRD, SEM, TG-DSC and particularly XPS were employed for characterizations. Sb2O4 and FeSbO4 are the only new phases detected. The formation of FeSbO4 is a more exothermic but slower reaction than oxidation of Sb2O3. A mechanical grinding of Sb2O3 and Fe2O3 leads to a significant dispersion of Sb2O3 possibly because of its low hardness. Dispersion of reference Sb2O4 in this way is negligible. During the heating of a mixture of Sb2O3 and Fe2O3 with an atomic ratio of Sb/Fe = 0.5 at 200-1000 degrees C in ambient air, the thermal spreading of Sb2O3 onto Fe2O3 increases with increasing temperature until Sb2O3 is oxidized into Sb2O4. The surface atomic ratio of Sb/Fe measured by XPS, R(Sb/Fe), reaches a maximum around 400 degrees C. The complete oxidation of Sb2O3 leads to a decrease in R(Sb/Fe) because of poorer dispersibility of Sb2O4. The formation of FeSbO4 starting at ca. 800 degrees C causes a further decrease in R(Sb/Fe), but the R(Sb/Fe) is still 3.2 times the nominal bulk Sb/Fe ratio when the Sb2O4 is completely transformed into FeSbO4.     

High-yield syntheses and reactivity studies of Fe10 "ferric wheels": structural, magnetic, and computational characterization of a star-shaped Fe8 complex

Convenient, high-yield routes have been developed to [Fe 10(OMe) 20(O 2CR) 10] ( 1) "ferric wheels" involving the alcoholysis of [Fe 3O(O 2CR) 6(H 2O) 3] (+) salts in MeOH in the presence of NEt 3. Reactivity studies have established [Fe 10(OMe) 20(O 2CMe) 10] ( 1a) to undergo clean carboxylate substitution with a variety of other RCO 2H groups to the corresponding [Fe 10(OMe) 20(O 2CR) 10] product. In contrast, the reaction with phenol causes a nuclearity change to give a smaller [Fe 8(OH) 4(OPh) 8(O 2CR) 12] ( 2) wheel. Similarly, reactions of [Fe 10(OMe) 20(O 2CR) 10] with the bidentate chelate ethylenediamine (en) cause a structural change to give either [Fe 8O 5(O 2CMe) 8(en) 8](ClO 4) 6 ( 3) or [Fe 2O(O 2CBu (t))(en) 4](NO 3) 3 ( 4), depending on conditions. Complex 3 possesses a "Christmas-star" Fe 8 topology comprising a central planar [Fe 4(mu 4-O)] (10+) square subunit edge-fused to four oxide-centered [Fe 3(mu 3-O)] (7+) triangular units. Variable-temperature, solid-state dc and ac magnetization studies on complexes 1a- 4 in the 5.0-300 K range established that all the complexes possess an S = 0 ground state. The magnetic susceptibility data for 4 were fit to the theoretical chi M versus T expression derived by the use of an isotropic Heisenberg spin Hamiltonian and the Van Vleck equation, and this revealed an antiferromagnetic exchange parameter with a value of J = -107.7(5) cm (-1). This value is consistent with that predicted by a previously published magnetostructural relationship. Theoretically computed values of the exchange constants in 3 were obtained with the ZILSH method, and the pattern of spin frustration within its core and the origin of its S = 0 ground state have been analyzed in detail.     

Hybrid open-framework iron phosphate--oxalates demonstrating a dual role of the oxalate unit

New inorganic-organic hybrid open-framework materials of the phosphate-oxalate family, [Fe2(H2O)2-(HPO4)2(C2O4)].H2O (I), [Fe2(H2O)2-(HPO4)2(C2O4)].2H2O (II), [C3N2H12]-[Fe2(HPO4)2(C2O4)1.5]2 (III), and [C3N2OH12][Fe2(HPO4)2(C2O4)1.5]2 (IV) have been synthesized hydrothermally in the presence of structure-directing amines. The amine molecules are incorporated in III and IV, whereas I and II are devoid of them. The oxalate units act as a bridge between the layers in all the compounds. The layers in I and II are entirely inorganic, being formed by FeO6 and PO4 units, whereas in III and IV oxalate units constitute the inorganic layers and act as the bridge between these layers. Such a dual role of the oxalate unit is unique and noteworthy. The formation of two types of inorganic layers in I and II consisting of four-, six-, and eight-membered rings, indicates the interconversions between the various rings in the phosphate--oxalates to be facile. All the phosphate--oxalates show antiferromagnetic ordering at low temperatures.     

Gelification: an effective measure for achieving differently sized biocompatible Fe3O4 nanocrystals through a single preparation recipe

Biocompatible Fe(3)O(4) nanocrystals were synthesized through the pyrolysis of ferric acetylacetonate (Fe(acac)(3)) in diphenyl oxide, in the presence of α,ω-dicarboxyl-terminated polyethylene glycol (HOOC-PEG-COOH) and oleylamine. Unusual gelification phenomena were observed from the aliquots extracted at different reaction stages after they were cooled to room temperature. By reaction time, the average size of the Fe(3)O(4) nanocrystals was tuned from 5.8 to 11.7 nm with an equilibrium size around 11.3 nm. By increasing the gelification degree of the stock solution, the equilibrium size of the Fe(3)O(4) nanocrystals was further increased from 11.3 to 18.9 nm. The underlying gel formation mechanism was investigated by using ultraviolet-visible absorption spectroscopy and Fourier transform infrared spectroscopy. The results suggest that the complexation between HOOC-PEG-COOH and Fe(acac)(3), with the help of oleylamine, results in large molecular networks, which are responsible for the gelification of the stock solution, while the interaction between the fragment of the molecular network and Fe(3)O(4) nanocrystal is responsible for the second gelification process observed during the early stage of reflux. To further investigate the particle growth behavior, small molecules released during the preparation were collected and analyzed by using photoelectron spectroscopy/photoionization mass spectroscopy (PES/PIMS). It was demonstrated that the pyrolysis of the Fe precursor is strongly correlated with the particle growth process. Further numerical simulations reveal that the first gelification process induced by the complexation between HOOC-PEG-COOH and Fe(acac)(3) largely alters the pyrolysis behavior of the Fe precursor; consequently, the equilibrium size of the resultant Fe(3)O(4) nanocrystals can effectively be tuned by the gelification degree of the stock solution.     

Polymetallic clusters of iron(III) with derivatised salicylaldoximes

The synthesis and magnetic properties of the compounds [HNEt(3)][Fe(2)(OMe)(Ph-sao)(2) (Ph-saoH)(2)].5MeOH (1.5MeOH), [Fe(3)O(Et-sao)(O(2)CPh)(5)(MeOH)(2)].3MeOH (2.3MeOH), [Fe(4)(Me-sao)(4)(Me-saoH)(4)] (3), [HNEt(3)](2)[Fe(6)O(2)(Me-sao)(4)(SO(4))(2)(OMe)(4)(MeOH)(2)] (4), [Fe(8)O(3)(Me-sao)(3)(tea)(teaH)(3)(O(2)CMe)(3)] (5), [Fe(8)O(3)(Et-sao)(3)(tea)(teaH)(3)(O(2)CMe)(3)] (6), and [Fe(8)O(3)(Ph-sao)(3)(tea)(teaH)(3)(O(2)CMe)(3)] (7) are reported (Me-saoH(2) is 2'-hydroxyacetophenone oxime, Et-saoH(2) is 2'-hydroxypropiophenone oxime and Ph-saoH(2) is 2-hydroxybenzophenone oxime). 1-7 are the first Fe(III) compounds synthesised using the derivatised salicylaldoxime ligands, R-saoH(2). 1 is prepared by treatment of Fe(2)(SO(4))(3).6H(2)O with Ph-saoH(2) in the presence of NEt(3) in MeOH; 2 prepared by treatment of Fe(ClO(4))(2).6H(2)O with Et-saoH(2) and NaO(2)CPh in the presence of NEt(4)OH in MeOH; 3 prepared by treatment of Fe(ClO(4))(2).6H(2)O with Me-saoH(2) and NaO(2)CCMe(3) in the presence of NEt(4)OH in MeOH; and 4 prepared by treatment of Fe(2)(SO(4))(3).6H(2)O with Me-saoH(2) in the presence of NEt(3) in MeOH. 4 is a rare example of a polynuclear iron complex containing a coordinated SO(4)(2-) ion. Compounds 5-7 are prepared by treatment of Fe(O(2)CMe)(2) with Me-saoH(2) (5), Et-saoH(2) (6), Ph-saoH(2) (7) in the presence of H(3)tea (triethanolamine) in MeOH, and represent the largest nuclearity Fe(III) clusters containing salicyladoxime-based ligands, joining a surprisingly small family of characterised octanuclear Fe complexes. Variable temperature magnetic susceptibilty measurements of 1, 3 and 5-7 reveal all five complexes possess S = 0 spin ground states; 2 possesses an S = 1/2 spin ground state, while 4 has an S = 4 +/- 1 spin ground state.     

Synthesis and characterization of magnetic poly(divinyl benzene)/Fe3O4, C/Fe3O4/Fe, and C/Fe onionlike fullerene micrometer-sized particles with a narrow size distribution

Magnetic poly(divinyl benzene)/Fe(3)O(4) microspheres with a narrow size distribution were produced by entrapping the iron pentacarbonyl precursor within the pores of uniform porous poly(divinyl benzene) microspheres prepared in our laboratory, followed by the decomposition in a sealed cell of the entrapped Fe(CO)(5) particles at 300 °C under an inert atmosphere. Magnetic onionlike fullerene microspheres with a narrow size distribution were produced by annealing the obtained PDVB/Fe(3)O(4) particles at 500, 600, 800, and 1100 °C, respectively, under an inert atmosphere. The formation of carbon graphitic layers at low temperatures such as 500 °C is unique and probably obtained because of the presence of the magnetic iron nanoparticles. The annealing temperature allowed control of the composition, size, size distribution, crystallinity, porosity, and magnetic properties of the produced magnetic microspheres.     

Oriented assembly of Fe3O4 nanoparticles into monodisperse hollow single-crystal microspheres

Magnetite nanoparticles of Fe3O4 were found to assemble into monodisperse hollow Fe3O4 microspheres with tunable diameters ranging from 200 to 400 nm and open pores on the shells in ethylene glycol in the presence of dodecylamine (DDA). The oriented assembly of nanoparticles conferred the individual hollow Fe3O4 microspheres a remarkable feature of single crystals. The morphologies of the products could be easily manipulated by varying the synthesis parameters. Increasing the concentration of DDA led to an obvious shape evolution of the products from rhombic nanoparticles to hollow microspheres, solid microspheres, and finally irregular nanoparticles, which were mainly attributed to the special self-assembly phenomenon of Fe3O4 nanoparticles in the solvothermal process.     

Fe_3O_4空心球/石墨烯复合吸波材料的制备及其性能

利用化学法制备氧化石墨烯(GO)与石墨烯(RGO),然后以水热法制备Fe3O4空心球/RGO复合吸波材料。XRD测试结果表明成功合成了具有立方结构的Fe3O4;SEM,TEM分析结果表明复合材料结构分布均匀,粒径约为100 nm。测试了材料在2~18 GHz波段的电磁参数,模拟计算了材料的反射率,结果显示复合材料的吸波性能比RGO有明显提升。当匹配厚度为7 mm时,复合材料具有两个吸收峰:在5.5 GHz处吸收峰为–9.5 d B,在16.5GHz处出现最大吸收峰–36 d B。     

Synthesis, characterization, and intracellular uptake of carboxyl-terminated poly(amidoamine) dendrimer-stabilized iron oxide nanoparticles

We report the synthesis and characterization of a group of carboxyl-functionalized poly(amidoamine) (PAMAM) dendrimers of generation 3 (G3) that were used for the stabilization of superparamagnetic iron oxide (Fe(3)O(4)) nanoparticles (NPs). Folic acid (FA) molecules were conjugated onto the dendrimer surfaces in an attempt to achieve specific targeted imaging of tumor cells that overexpress FA receptors using dendrimer-stabilized Fe(3)O(4) NPs. Fe(3)O(4) NPs were synthesized using controlled co-precipitation of Fe(ii) and Fe(iii) ions and the formed dendrimer-stabilized Fe(3)O(4) NPs were characterized using transmission electron microscopy (TEM) and polyacrylamide gel electrophoresis (PAGE). The intracellular uptake of dendrimer-stabilized Fe(3)O(4) NPs was tested in vitro using KB cells (a human epithelial carcinoma cell line) that overexpress FA receptors. It appears that carboxyl-terminated PAMAM dendrimer-stabilized Fe(3)O(4) NPs can be uptaken by KB cells regardless of the repelling force between the negatively charged cells and the negatively charged particles. In the presence of a large amount of carboxyl terminal groups on the dendrimer surface, the receptor-mediated endocytosis of Fe(3)O(4) NPs stabilized by FA-modified dendrimers was not facilitated. It implies that the surface charge of dendrimer-stabilized magnetic iron oxide NPs in biological medium is an important factor influencing their biological performance.     

Preparation of water-soluble magnetic nanocrystals using aryl diazonium salt chemistry

A novel and facile methodology for the in situ surface functionalization of Fe(3)O(4) nanoparticles is proposed, based on the use of aryl diazonium salts chemistry. The grafting reaction involves the formation of diazoates in a basic medium. These species are unstable and dediazonize along a homolytic pathway to give aryl radicals which further react with the Fe(3)O(4) NPs during their formation and stop their growth. Advantages of the present approach rely not only on the simplicity, rapidity, and efficiency of the procedure but also on the formation of strong Fe(3)O(4)-aryl surface bonds, highly suitable for further applications.     

Decoration of Electrospun Nanofibers with Magnetic Nanoparticles via Electrospinning and Sol-gel Process

Polyacrylonitrile(PAN)/Fe 3 O 4 composite nanofibers were successfully obtained through electrospinning and sol-gel technology. The resulting magnetic Fe 3 O 4 nanoparticles were homogeneously distributed on the surface of PAN nanofibers and the diameters of polyacrylonitrile nanofibers and nanoparticles were easily controlled, respectively. The distribution of Fe 3 O 4 nanoparticles inside the nanofibrous composite was investigated by field emission scanning electron microscopy and transmission electron microscopy. X-ray diffraction reveals the presence of Fe 3 O 4 nanoparticles in the composite nanofiber. The resulting sample shows a super paramagnetic behavior.