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Sample records for fe nanoparticles synthesized

  1. Magnetic properties of Fe-oxide and (Fe, Co) oxide nanoparticles synthesized in polystyrene resin matrix

    Science.gov (United States)

    Rodak, D.; Kroll, E.; Tsoi, G. M.; Vaishnava, P. P.; Naik, R.; Wenger, L. E.; Suryanarayanan, R.; Naik, V. M.; Boolchand, P.

    2003-03-01

    Magnetic nanoparticles have potential applications ranging from drug delivery and imaging in the medical field to sensing and memory storage in technology. The preparation, structure, and physical properties of iron oxide-based nanoparticles synthesized by ion exchange in a polystyrene resin matrix have been investigated. Employing a synthesis method developed originally by Ziolo, et. al^1, nanoparticles were prepared in a sulfonated divinyl benzene polystyrene resin matrix using various aqueous solutions of (1) FeCl_2, (2) FeCl_3, (3) FeCl2 : 2FeCl3 , (4) 9FeCl2 : CoCl_2, and (5) 4FeCl2 : CoCl_2. Powder x-ray diffraction measurements were used to identify the phases present while transmission electron microscopy was used for particle size distribution determinations. SQUID magnetization measurements (field-cooled and zero-field-cooled) and Fe^57 Mössbauer effect measurements indicate the presence of ferromagnetic iron oxide phases and a superparamagnetic behavior with blocking temperatures (T_B) varying from 50 K to room temperature. Nanoparticles synthesized using a stoichiometric mixture of FeCl2 and FeCl3 exhibit the lowest TB and smallest particle size distribution. The Mössbauer effect measurements have also been used to identify the iron oxides phases present and their relative amounts in the nanoparticles ^1R.F. Ziolo, et al., Science 207, 219 (1992). *Permanent address: Kettering University, Flint, MI 48504

  2. Induction heating studies of combustion synthesized MgFe2O4 nanoparticles for hyperthermia applications

    International Nuclear Information System (INIS)

    Khot, V.M.; Salunkhe, A.B.; Thorat, N.D.; Phadatare, M.R.; Pawar, S.H.

    2013-01-01

    The structural, magnetic and ac magnetically induced heating characteristics of combustion synthesized MgFe 2 O 4 nanoparticles have been investigated for application in magnetic particle hyperthermia. As prepared nanoparticles showed ferrimagnetic behavior at room temperature with magnetization of about 33.83 emu/g at ±15 kOe. The solid state MgFe 2 O 4 nanoparticles exhibited specific absorption rate (SAR) of about 297 W/g at physiological safe range of frequency and amplitude. The increase in SAR and heating temperature in ac magnetic field was thought to be due to enhancement in magnetic hysteresis loss caused by dipole–dipole interactions in combustion synthesized MgFe 2 O 4 nanoparticles. - Highlights: ► Highly crystalline pure MgFe 2 O 4 nanoparticles were synthesized by low temperature combustion. ► Effect of ac magnetic field and nanoparticles concentration on heating characteristics of MgFe 2 O 4 nanoparticles was studied. ► Combustion synthesized MgFe 2 O 4 nanoparticles show highest specific absorption rate of 297 Wg −1 . ► The reported high value of specific absorption rate is advantageous for its use in magnetic particle hyperthermia

  3. Magnetorheology of colloidal dispersion containing Fe nanoparticles synthesized by the arc-plasma method

    International Nuclear Information System (INIS)

    Noma, Junichi; Abe, Hiroya; Kikuchi, Takehito; Furusho, Junji; Naito, Makio

    2010-01-01

    Spherical crystalline Fe nanoparticles, ∼100 nm in diameter, were synthesized under Ar-50% H 2 arc-plasma. These nanoparticles were dispersed in silicone oil after silane treatment on as-grown thin oxide layer (∼2 nm) to make their surfaces hydrophobic. The resulting Fe nanoparticles exhibited a high saturation magnetization of ∼190 emu/g at room temperature. The static magnetorheological behavior was measured for the colloidal dispersion (solid concentration: 15 vol%) at room temperature under magnetic flux densities of 0-0.3 T, using a parallel-plate-type commercial rheometer. The yield stress continuously increased with magnetic flux density, demonstrating the Bingham plastic behavior. Moreover, subjecting the sample to a magnetic flux density of 0.3 T increased the yield stress by ∼10 2 . Additionally, the colloidal dispersion exhibited good stability against sedimentation.

  4. Magnetorheology of colloidal dispersion containing Fe nanoparticles synthesized by the arc-plasma method

    Science.gov (United States)

    Noma, Junichi; Abe, Hiroya; Kikuchi, Takehito; Furusho, Junji; Naito, Makio

    2010-07-01

    Spherical crystalline Fe nanoparticles, ˜100 nm in diameter, were synthesized under Ar-50% H 2 arc-plasma. These nanoparticles were dispersed in silicone oil after silane treatment on as-grown thin oxide layer (˜2 nm) to make their surfaces hydrophobic. The resulting Fe nanoparticles exhibited a high saturation magnetization of ˜190 emu/g at room temperature. The static magnetorheological behavior was measured for the colloidal dispersion (solid concentration: 15 vol%) at room temperature under magnetic flux densities of 0-0.3 T, using a parallel-plate-type commercial rheometer. The yield stress continuously increased with magnetic flux density, demonstrating the Bingham plastic behavior. Moreover, subjecting the sample to a magnetic flux density of 0.3 T increased the yield stress by ˜10 2. Additionally, the colloidal dispersion exhibited good stability against sedimentation.

  5. Anti-friction performance of FeS nanoparticle synthesized by biological method

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Lu Hai, E-mail: lhzhou@t.shu.edu.cn [School of Materials Science and Engineering, Shanghai University, Shanghai 200444 (China); Wei, Xi Cheng [School of Materials Science and Engineering, Shanghai University, Shanghai 200444 (China); Ma, Zi Jian [Pipe and Bar Division of Baoshan Iron & Steel Co., Ltd., Shanghai 200941 (China); Mei, Bin [Shanghai Medical Instrumentation College, Shanghai 200093 (China)

    2017-06-15

    Highlights: • FeS nanoparticles were successfully prepared by a biological method. • The anti-friction performance of prepared nanoparticle under oil lubricating and dry condition were analyzed. • The anti-friction mechanism of FeS nanoparticle was discussed. - Abstract: FeS nanoparticle is prepared by a biological method. The size, morphology and structure of the FeS nanoparticle are characterized by the means of X-ray diffraction and transmission electron microscopy. The anti-friction behavior of the FeS nanoparticle as a lubricating oil additive is evaluated in the engine oil by using a face-to-face contact mode. The worn surface is characterized by using the scanning electron microscopy and secondary ion mass spectroscopy in order to find the reasons resulting in the reduction of friction coefficient due to the addition of the FeS nanoparticle. The anti-friction mechanism of the FeS nanoparticle is elucidated based on the experimental results.

  6. A novel hydrothermal approach for synthesizing α-Fe2O3, γ-Fe2O3 and Fe3O4 mesoporous magnetic nanoparticles

    International Nuclear Information System (INIS)

    Jayanthi, S. Amala; Nathan, D. Muthu Gnana Theresa; Jayashainy, J.; Sagayaraj, P.

    2015-01-01

    A novel method to synthesize the three phases of iron oxide nanoparticles (hematite, maghemite and magnetite) using the same non-toxic inorganic precursors via a water–organic interface under the low temperature hydrothermal conditions is reported. The synthesized particles are characterized by Powder X-ray Diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM) and Transmission Electron Microscopy (TEM). The Brunauer–Emmett–Teller (BET) results reveal the mesoporous nature of the particles. The magnetic properties of the nanoparticles are studied by Vibrating Sample Magnetometer (VSM) at various low temperatures and also at room temperature. The XRD peaks corresponding to each sample clearly depict the presence of the respective phase of the as-prepared magnetic nanoparticles. The nanoparticles of maghemite and magnetite have saturation magnetization of 58.56 and 40.30 emu/g respectively at room temperature, whereas the particles of hematite possess very low saturation magnetization value of 1.89 emu/g. Further, the magnetization is studied at four different temperatures and the zero field cooled (ZFC) and field cooled (FC) magnetization are reported. - Graphical abstract: Display Omitted - Highlights: • Hematite, maghemite and magnetite are obtained under hydrothermal synthesis. • α-Fe 2 O 3 , γ-Fe 2 O 3 and Fe 3 O 4 prepared are mesoporous and nearly monodisperse. • Near superparamagnetism is observed at room temperature for maghemite and magnetite

  7. Synthesis of Fe Nanoparticles Functionalized with Oleic Acid Synthesized by Inert Gas Condensation

    Directory of Open Access Journals (Sweden)

    L. G. Silva

    2014-01-01

    Full Text Available In this work, we study the synthesis of monodispersed Fe nanoparticles (Fe-NPs in situ functionalized with oleic acid. The nanoparticles were self-assembled by inert gas condensation (IGC technique by using magnetron-sputtering process. Structural characterization of Fe-NPs was performed by transmission electron microscopy (TEM. Particle size control was carried out through the following parameters: (i condensation zone length, (ii magnetron power, and (iii gas flow (Ar and He. Typically the nanoparticles generated by IGC showed diameters which ranged from ~0.7 to 20 nm. Mass spectroscopy of Fe-NPs in the deposition system allowed the study of in situ nanoparticle formation, through a quadrupole mass filter (QMF that one can use together with a mass filter. When the deposition system works without quadrupole mass filter, the particle diameter distribution is around +/−20%. When the quadrupole is in line, then the distribution can be reduced to around +/−2%.

  8. Electrokinetic properties of PMAA functionalized NiFe2O4 nanoparticles synthesized by thermal plasma route

    Science.gov (United States)

    Bhosale, Shivaji V.; Mhaske, Pravin; Kanhe, N.; Navale, A. B.; Bhoraskar, S. V.; Mathe, V. L.; Bhatt, S. K.

    2014-04-01

    The magnetic nickel ferrite (NiFe2O4) nanoparticles with an average size of 30nm were synthesised by Transferred arc DC Thermal Plasma route. The synthesized nickel ferrite nanoparticles were characterized by TEM and FTIR techniques. The synthesized nickel ferrite nanoparticles were further functionalized with PMAA (polymethacrylic acid) by self emulsion polymerization method and subsequently were characterized by FTIR and Zeta Analyzer. The variation of zeta potential with pH was systematically studied for both PMAA functionalized (PNFO) and uncoated nickel ferrite nanoparticles (NFO). The IEP (isoelectric points) for PNFO and NFO was determined from the graph of zeta potential vs pH. It was observed that the IEP for NFO was at 7.20 and for PNFO it was 2.52. The decrease in IEP of PNFO was attributed to the COOH functional group of PMAA.

  9. The magnetic characterization of Fe doped TiO{sub 2} semiconducting oxide nanoparticles synthesized by sol–gel method

    Energy Technology Data Exchange (ETDEWEB)

    Yeganeh, M., E-mail: mahboubeh.yeganeh@yahoo.co.uk [Department of Physics, Kosar University of Bojnord, P.O. Box 94104455 (Iran, Islamic Republic of); Shahtahmasebi, N.; Kompany, A. [Department of Physics, Ferdowsi University of Mashhad (Iran, Islamic Republic of); Karimipour, M. [Department of Physics, Vali-e-Asr University of Rafsanjan (Iran, Islamic Republic of); Razavi, F. [Department of Physics, Brock University (Canada); Nasralla, N.H.S. [Electron Microscope and Thin Film Department, Physics Division, 33 El Buhouth st., Dokki, 12622 Giza (Egypt); Šiller, L. [School of Chemical Engineering and Advanced Materials, Newcastle University, NE1 7RU (United Kingdom)

    2017-04-15

    In this work Fe doped TiO{sub 2} nanoparticles were synthesized at different Fe/Ti molar ratio from 1% to 5% by sol-gel technique. The post annealing of the samples was carried out at T=400, 600, and 800 °C. HRTEM of the samples revealed that the mean size of the nanoparticles increases from about 8 nm to about 100 nm as the annealing temperature increased. SQUID magnetometry of 1% and 5% Fe doped TiO{sub 2} has shown mixed ferromagnetic and paramagnetic phases within the crystal while ferromagnetic order with T{sub c} about 350 K was only observed in 5% Fe:TiO{sub 2} sample annealed at T=800 °C. The oxygen vacancy mediated ferromagnetic (FM) interaction could be responsible for the observed FM.

  10. Size effect on L10 ordering and magnetic properties of chemically synthesized FePt and FePtAu nanoparticles

    Science.gov (United States)

    Jia, Zhiyong; Kang, Shishou; Shi, Shifan; Nikles, David E.; Harrell, J. W.

    2005-05-01

    There is growing evidence that FePt nanoparticles become increasingly difficult to chemically order as the size approaches a few nanometers. We have studied the chemical ordering of FePt and FePtAu nanoparticle arrays as a function of particle size. Monodisperse Fe49Pt51 and Fe48Pt44Au8 nanoparticles with a size about 6nm were synthesized by the simultaneous decomposition of iron pentacarbonyl and reduction of platinum acetylacetonate and gold (III) acetate in a mixture of phenyl ether and hexadecylamine (HDA), with 1-adamantanecarboxylic acid and HDA as stabilizers. The nanoparticles were dispersed in toluene, films of the particles were cast onto silicon wafers from the dispersion, and the films were annealed in a tube furnace with flowing Ar +5%H2. The magnetic anisotropy and switching volumes were determined from time- and temperature-dependent coercivity measurements. By comparing with 3-nm FePt and FePtAu nanoparticles of comparable composition, the phase transformation is easier for the larger particles. Under the same annealing conditions, the larger particles have higher anisotropy and order parameter. Additive Au is very effective in enhancing the chemical ordering in both small and large particles, with x-ray diffraction superlattice peaks appearing after annealing at 350°C. Dynamic remnant coercivity measurements and magnetic switching volumes suggest particle aggregation at the higher annealing temperatures in both small and large particles.

  11. The magnetic and colloidal properties of CoFe2O4 nanoparticles synthesized by co-precipitation.

    Science.gov (United States)

    Gyergyek, Sašo; Drofenik, Miha; Makovec, Darko

    2014-01-01

    Magnetic CoFe(2)O(4) nanoparticles were synthesized by co-precipitation at 80 °C. This co-precipitation was achieved by the rapid addition of a strong base to an aqueous solution of cations. The investigation of the samples that were quenched at different times after the addition of the base, using transmission electron microscopy (TEM) coupled with energy-dispersive X-ray spectroscopy (EDXS) and X-ray powder diffractometry, revealed the formation of a Co-deficient amorphous phase and Co(OH)(2), which rapidly reacted to form small CoFe(2)O(4) nanoparticles. The nanoparticles grew with the time of aging at elevated temperature. The colloidal suspensions of the nanoparticles were prepared in both an aqueous medium and in a non-polar organic medium, with the adsorption of citric acid and ricinoleic acid on the nanoparticles, respectively. The measurements of the room-temperature magnetization revealed the ferrimagnetic state of the CoFe(2)O(4) nanoparticles, while their suspensions displayed superparamagnetic behaviour.

  12. A novel sol–gel process to facilely synthesize Ni{sub 3}Fe nanoalloy nanoparticles supported with carbon and silica

    Energy Technology Data Exchange (ETDEWEB)

    Xu, L.Q. [Institute of Materials Engineering, Nanjing National Laboratory of Microstructures, Jiangsu Provincial Laboratory for Nanotechnology and School of Physics, Nanjing University, Nanjing 210093 (China); School of Physics and Information Technology, Ningxia Teachers University, Guyuan, Ningxia 756000 (China); Chen, L.Y.; Huang, H.F.; Xie, R.; Xia, W.B.; Wei, J.; Zhong, W. [Institute of Materials Engineering, Nanjing National Laboratory of Microstructures, Jiangsu Provincial Laboratory for Nanotechnology and School of Physics, Nanjing University, Nanjing 210093 (China); Tang, S.L., E-mail: tangsl@nju.edu.cn [Institute of Materials Engineering, Nanjing National Laboratory of Microstructures, Jiangsu Provincial Laboratory for Nanotechnology and School of Physics, Nanjing University, Nanjing 210093 (China); Du, Y.W. [Institute of Materials Engineering, Nanjing National Laboratory of Microstructures, Jiangsu Provincial Laboratory for Nanotechnology and School of Physics, Nanjing University, Nanjing 210093 (China)

    2014-04-01

    Graphical abstract: The TEM and HRTEM images and the magnetization curves taken in both zero-field-cooled (ZFC) and field-cooled (FC) modes of Ni{sub 3}Fe nanoparticles calcined at 300 °C for 2 h under Ar flowing. Display Omitted - Highlights: • Ultrafine Ni{sub 3}Fe nanoalloy nanoparticles were synthesized via a modified novel sol–gel process. • The prepared Ni{sub 3}Fe nanoalloy nanoparticles have a narrow size distribution. • The Ni{sub 3}Fe nanoparticles exhibit superparamagnetic behaviors at room temperature. - Abstract: In this paper, we present a modified novel silica sol–gel process and explored the possibility, for the first time, to synthesize binary nanoalloy nanoparticles. We successfully prepared ultrafine Ni{sub 3}Fe nanoparticles supported with carbon and silica via this simple one-pot reaction without H{sub 2} reduction. X-ray diffraction (XRD) and selected area electron diffraction (SAED) investigations of the Ni{sub 3}Fe nanoparticles show that the nanoparticles have a face-centered-cubic (fcc) crystal structure. The TEM images show that grain sizes of Ni{sub 3}Fe nanoparticles have a narrow size distribution. Moreover, the grain size of the nanoparticles is not very sensitive to the elevated annealing temperature. The Ni{sub 3}Fe nanoparticles exhibit typical superparamagnetic behavior at room temperature, and the blocking temperatures (T{sub B}) are determined by the temperature-dependent magnetization (M–T curves) measurements. This novel silica sol–gel method is expected to have broad applications in synthesizing nanoalloy nanoparticles.

  13. Magnetic properties of α-Fe2O3 nanoparticle synthesized by a new hydrothermal method

    International Nuclear Information System (INIS)

    Giri, S.; Samanta, S.; Maji, S.; Ganguli, S.; Bhaumik, A.

    2005-01-01

    Nanoparticles of α-Fe 2 O 3 have been prepared using a hydrothermal synthesis method in aqueous-organic microemulsion under mild alkaline condition. The condensation reaction was optimized in the presence of a cationic surfactant cetyltrimethylammonium bromide (CTAB). It was found that the size and nature of the α-Fe 2 O 3 nanoparticle strongly depends on the pH, oxalic acid and CTAB as well as tetramethylammonium hydroxide (TMAOH, alkali source) concentrations. The uniformity of the particle size was checked by the transmission electron microscopy while the single phase of the nanocrystalline α-Fe 2 O 3 was characterized using powder X-ray diffraction. The Moessbauer study exhibited a sextet pattern with internal field smaller than that of the bulk counterpart. The temperature variation of magnetization showed a broad maximum at around 125 K while the field-cooled effect of the magnetization showed the branching between the field cooled and zero field cooled magnetization up to 340 K. A large anisotropy has been observed from the analysis of magnetization curve as well as from the large blocking temperature. The estimation of the particle size from the magnetization curve was found to be in close agreement with the TEM results

  14. Low Temperature Ferromagnetism and Optical Properties of Fe Doped ZnO Nanoparticles Synthesized by Sol-Gel Method

    Directory of Open Access Journals (Sweden)

    B. Sathya

    2017-06-01

    Full Text Available In this present investigation, pure and Fe doped Zinc oxide nanoparticles were successfully synthesized by sol gel method.The structural and optical properties were examined by using X-ray diffraction (XRD, Scanning electron microscope (SEM, Transmission electron microscope (TEM, Ultraviolet spectroscopy and Photoluminescence (PL techniques.The structural characterization of XRD analysis confirmed the phase purity of the samples and crystallite size can be decreased with increasing doping concentrations.SEM image show that nanoparticles in spherical shape. The optical band gap calculated through UV-visible spectroscopy is found to be increasing from 3.48 to 3.57eV. TEM analysis depicted the crystallinity of nanoparticles prepared and chemical composition conformed the EDAX analysis. The PL spectra reveal that, Fe doped ZnO exhibit a decrease in intensity of the band edge emission peak while the intensity of the deep level emission peak increases.The enhancement of low temperature ferromagnetism in ZnO: Fe was achieved.

  15. Violet emission from Fe doped ZnO nanoparticles synthesized by precipitation method

    Energy Technology Data Exchange (ETDEWEB)

    Kanchana, S., E-mail: skanchana09@gmail.com [PG & Research Department of Physics, Urumu Dhanalaksmi College, Tiruchirapalli 620019 (India); Chithra, M. Jay [Nanomaterials Research Laboratory, Department of Physics, Government Arts College, Karur 639005 (India); Ernest, Suhashini [PG & Research Department of Physics, Urumu Dhanalaksmi College, Tiruchirapalli 620019 (India); Pushpanathan, K. [Nanomaterials Research Laboratory, Department of Physics, Government Arts College, Karur 639005 (India)

    2016-08-15

    In this article we have reported the synthesis of Fe doped zinc oxide nanoparticles by the chemical precipitation method. The structural, compositional and optical properties have been examined by powder X-ray diffractometer, scanning electron microscope, transmission electron microscope, ultraviolet–visible and spectrophotometer. X-ray diffraction analysis confirmed the crystallites are in nanometer size and the sample contains polycrystals with hexagonal wurtzite structure. The average crystallite size has been found to increase from 25 nm to 36 nm with increase in Fe concentration. Scanning electron microscope result also confirmed the nanosize of the particles. Ultraviolet–visible spectrum of Fe doped zinc oxide shows a red shift with respect to undoped zinc oxide. The band gap of the samples was calculated from ultraviolet–visible spectrum and it is narrow from 3.30 eV to 3.23 eV with increasing Fe dopant upto 6%. The stretching bonds in Zn– Fe–O have been observed in FTIR spectra.

  16. Oleic-acid-coated CoFe2O4 nanoparticles synthesized by co-precipitation and hydrothermal synthesis

    International Nuclear Information System (INIS)

    Gyergyek, Sašo; Drofenik, Miha; Makovec, Darko

    2012-01-01

    Highlights: ► Synthesis of oleic-acid-coated CoFe 2 O 4 nanoparticles from an aqueous solution. ► During the co-precipitation of Co 2+ /Fe 3+ single-phase spinel forms. ► During the co-precipitation of Co 2+ /Fe 2+ , feroxyhyte forms in addition to spinel. ► Oleic acid increases the spinel formation temperature and limits particle growth. ► Colloidal suspensions of ferrimagnetic CoFe 2 O 4 were prepared. - Abstract: Oleic-acid-coated CoFe 2 O 4 nanoparticles were synthesized by co-precipitation and hydrothermal synthesis. The coprecipitation of the nanoparticles was achieved by the rapid addition of a strong base to an aqueous solution of cations in the presence of the oleic acid surfactant, or without this additive. The nanoparticles were also synthesized by a hydrothermal treatment of suspensions of the precipitates, coprecipitated at room temperature in the presence of the oleic acid, or without it. The influence of the synthesis conditions, such as the valence state of the iron cation in the starting aqueous solution, the temperature of the treatment and the presence of oleic acid, on the particles size was systematically studied. X-ray powder diffractometry (XRD) and transmission electron microscopy (TEM) coupled with energy-dispersive X-ray spectroscopy (EDS) revealed that, although spinel forms at room temperature, a substantial amount of Co was incorporated within the secondary, feroxyhyte-like phase when the iron cation was in the 2+ state. In contrast, when iron was in the 3+ state, the spinel forms at elevated temperatures of approximately 60 °C. The presence of the oleic acid further increased the formation temperature for the stoichiometric spinel. Moreover, the oleic acid impeded the particles’ growth and enabled the preparation of colloidal suspensions of the nanoparticles in non-polar organic solvents. The nanoparticles’ size was successfully controlled by the temperature of the synthesis in the region where superparamagnetism

  17. Magnetic properties and magnetization reversal mechanism of Nd-Fe-B nanoparticles synthesized by a sol-gel method

    Science.gov (United States)

    Rahimi, Hamed; Ghasemi, Ali; Mozaffarinia, Reza; Tavoosi, Majid

    2017-12-01

    Nd-Fe-B oxide powders with various pH were prepared using chloride and nitrate precursors including NdCl3·6H2O, FeCl3·6H2O, H3BO3, Nd2O3, Fe(NO3)3·9H2O, HNO3, citric acid (CA), ethylene glycol (EG) by Pechini type sol-gel method. The pH of chloride and nitrate base sols were 0 and 2.2, respectively. Mixed oxide powders were obtained by calcination and annealing the gels. These oxides by using a reduction-diffusion process under high vacuum and employing CaH2 as reducing agent at 800 °C were hated to prepare Nd2Fe14B nanoparticles. The role of pH on phase, morphologies, microstructure, and magnetic properties of the powders were investigated. The results show that with a decrease in pH, the average particle size and coercivity of Nd-Fe-B oxide powders were decreased and increased, respectively. Nd2Fe14B nanoparticles were formed successfully after reduction process. The average particle size of reduction treated products were 30 and 65 nm for powders which made of chloride and nitrate base metal salts, respectively. Final powders which made of chloride and nitrate base metal salts had a saturation magnetization of 127.7 emu/g and 122.8 emu/g while the coercivity of samples were 3.32 kOe and 1.82 kOe, respectively. The experimental results in the angular dependence of coercivity indicated that the normalized coercivity of the permanent magnets Hc(θ)/Hc(0) obeys the 1/cosθ law and intermediate between the 1/cosθ law and Stoner-Wohlfarth formula for different Nd2Fe14B magnets which made of nitrate and chloride base metal salts, respectively. Also, the results show that different Nd2Fe14B magnets which made of nitrate and chloride base metal salts had the maximum energy product of 5 and 16 MGOe, respectively. The Henkel plot showed that magnetic phases in synthesized NdFeB magnets which made of chloride and nitrate base metal salts were coupled by exchange and dipolar interactions, respectively. Different average particle size, morphology and microstructure were

  18. Control of the shape and size of iron oxide (α-Fe2O3 nanoparticles synthesized through the chemical precipitation method

    Directory of Open Access Journals (Sweden)

    Abdelmajid Lassoued

    Full Text Available Hematite (α-Fe2O3 nanoparticles were synthesized via a simple chemical precipitation method. The impact of varying the concentration of precursor on the crystalline phase, size and morphology of α-Fe2O3 products was explored. The characteristic of the synthesized hematite nanoparticles were evaluated by X-ray diffraction (XRD, Transmission Electron Microscopy (TEM, Scanning Electron Microscopy (SEM, Fourier Transform Infra-Red (FT-IR spectroscopy, Raman spectroscopy, Differential Thermal Analysis (DTA, Thermo Gravimetric Analysis (TGA, Ultraviolet–Visible (UV–Vis analysis and Photoluminescence (PL. XRD data revealed a rhombohedral (hexagonal structure with the space group R-3c in all samples. Uniform spherical like morphology was confirmed by TEM and SEM. The result revealed that the particle sizes were varied between 21 and 82 nm and that the increase in precursor concentration (FeCl3, 6H2O is accompanied by an increase in the particle size of 21 nm for pure α-Fe2O3 synthesized with [Fe3+] = 0.05 M at 82 nm for pure α-Fe2O3 synthesized with [Fe3+] = 0.4 M. FT-IR confirms the phase purity of the nanoparticles synthesized. The Raman spectroscopy was used not only to prove that we have synthesized pure hematite but also to identify their phonon modes. The thermal behavior of compound was studied by using TGA/DTA results: The TGA showed three mass losses, whereas DTA resulted in three endothermic peaks. Besides, the optical investigation revealed that samples have an optical gap of about 2.1 eV and that this value varies as a function of the precursor concentration. Keywords: Nanoparticles, Hematite (α-Fe2O3, Precipitation, Precursor, Size, Band gap

  19. Effect of surface properties of NiFe2O4 nanoparticles synthesized by dc thermal plasma route on antimicrobial activity

    Science.gov (United States)

    Bhosale, S. V.; Ekambe, P. S.; Bhoraskar, S. V.; Mathe, V. L.

    2018-05-01

    The present work reports the role of surface properties of NiFe2O4 nanoparticles on the antimicrobial activity. The NiFe2O4 nanoparticles were synthesized by gas phase condensation and chemical co-precipitation route. These nanoparticles were extensively investigated using X-ray diffraction, transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and electro-kinetic property measurements. The HRTEM was used to analyze surface morphology of nickel ferrite nanoparticles obtained by two different routes. Electro-kinetic properties of the nanoparticles under investigation were recorded, analyzed and correlated with the antimicrobial properties. It was observed that nickel ferrite nanoparticles synthesized by thermal plasma route (NFOTP) formed highly stable colloidal solution as compared to chemically synthesized (NFOCP), as the later tends to agglomerate due to low surface charge. The antimicrobial activity of NiFe2O4 nanoparticles were investigated on two Gram positive bacteria Staphylococcus aureus and Streptococcus pyogenes, two Gram negative bacteria Escherichia coli and Salmonella typhimurium and one fungal species Candida albicans. It was noted that the surface properties of NiFe2O4 particles have revealing effect on the antimicrobial activity. The NFOTP nanoparticles showed significant activity for gram negative E. coli bacteria however no activity was observed for other bacteria's and fungi under study. Moreover NFOCP particles did not show any significant activity for both bacteria's and fungi. Further, antimicrobial activity of nickel ferrite nanoparticles were studied even for different concentration to obtain the minimum inhibition concentration (MIC).

  20. Lithium-ions diffusion kinetic in LiFePO4/carbon nanoparticles synthesized by microwave plasma chemical vapor deposition for lithium-ion batteries

    Science.gov (United States)

    Gao, Chao; Zhou, Jian; Liu, Guizhen; Wang, Lin

    2018-03-01

    Olivine structure LiFePO4/carbon nanoparticles are synthesized successfully using a microwave plasma chemical vapor deposition (MPCVD) method. Microwave is an effective method to synthesize nanomaterials, the LiFePO4/carbon nanoparticles with high crystallinity can shorten diffusion routes for ionic transfer and electron tunneling. Meanwhile, a high quality, complete and homogenous carbon layer with appropriate thickness coating on the surface of LiFePO4 particles during in situ chemical vapor deposition process, which can ensure that electrons are able to transfer fast enough from all sides. Electrochemical impedance spectroscopy (EIS) is carried out to collect information about the kinetic behavior of lithium diffusion in LiFePO4/carbon nanoparticles during the charging and discharging processes. The chemical diffusion coefficients of lithium ions, DLi, are calculated in the range of 10-15-10-9 cm2s-1. Nanoscale LiFePO4/carbon particles show the longer regions of the faster solid-solution diffusion, and corresponding to the narrower region of the slower two-phase diffusion during the insertion/exaction of lithium ions. The CV and galvanostatic charge-discharge measurements show that the LiFePO4/carbon nanoparticles perform an excellent electrochemical performance, especially the high rate capacity and cycle life.

  1. Growth mechanism and magnetism in carbothermal synthesized Fe{sub 3}O{sub 4} nanoparticles from solution combustion precursors

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xuanli [School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing, 100083 China (China); Qin, Mingli, E-mail: qinml@mater.ustb.edu.cn [School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing, 100083 China (China); Cao, Zhiqin [School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing, 100083 China (China); School of Materials Science and Engineering, Pan Zhihua University, Pan Zhihua, 617000 China (China); Jia, Baorui; Gu, Yueru; Qu, Xuanhui [School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing, 100083 China (China); Volinsky, Alex A. [Department of Mechanical Engineering, University of South Florida, Tampa, 33620 (United States)

    2016-12-15

    Magnetic Fe{sub 3}O{sub 4} nanoparticles were prepared by carbothermal reduction using solution combustion synthesis precursors derived from ferric nitrate (oxidizer), glycine (fuel) and glucose (carbon source) mixed solution. In this paper, the growth mechanism and magnetism in Fe{sub 3}O{sub 4} nanoparticles were investigated by adjusting the glucose content in precursor and the heat temperature in carbothermal process. The products were analyzed by X-ray diffraction, Field emission scanning electron microscopy, Infrared adsorption method and Vibrating sample magnetometry. The results revealed that the more amount of glucose, the earlier Fe{sub 3}O{sub 4} phase generated as temperature increasing. Depending on glucose content and thermal temperature, the average grain size of Fe{sub 3}O{sub 4} nanoparticles varied from 19.9 nm to 48 nm and saturation magnetization changed from 21.2 emu/g to 71.77 emu/g, which indicated that the saturation magnetization of Fe{sub 3}O{sub 4} nanoparticles fell off as the average grain size decreasing. These results were crucial not only from the application stand-point, but more importantly leaded to a new platform for further studies of high quality magnetic Fe{sub 3}O{sub 4} particles at nanoscale. - Highlights: • Solution combustion. • Carbothermal. • Fe{sub 3}O{sub 4} nanoparticles. • Magnetic properties.

  2. Photoluminescence and magnetic properties of Fe-doped ZnS nano-particles synthesized by chemical co-precipitation

    Energy Technology Data Exchange (ETDEWEB)

    Nie Eryong; Liu Donglai; Zhang Yunsen; Bai Xue; Yi Liang; Jin Yong; Jiao Zhifeng [School of Materials Science and Engineering, Sichuan University, Chengdu 610064, Sichuan (China); Sun Xiaosong, E-mail: sunxs@scu.edu.cn [School of Materials Science and Engineering, Sichuan University, Chengdu 610064, Sichuan (China)

    2011-08-15

    This paper is focusing on the synthesis of Zn{sub 1-x}Fe{sub x}S nano-particles with x = 0, 0.1 and 0.2 by chemical co-precipitation method, the prepared of which are characterized by XRD, EDS, TEM, PL, magnetization versus field behavior and M-T curve. In the XRD patterns, Zn{sub 1-x}Fe{sub x}S nano-particles are shown of cubic zinc blende structure, and the broadening diffraction peaks consistent with the small-size characteristic of nano-materials. The diameter of nano-particles is between 3.3 and 5.5 nm according to the HR-TEM images. The EDS data confirm the existence of Fe ions in Fe-doped ZnS nanoparticles. There we found that Fe-doping did not import new energy bands or defect states, but reduced the intensity of PL peaks. The magnetization versus field behaviors were illustrated by the M-H curves at both 5 K and 300 K, respectively, where no remanence or coercive force was observed. This phenomenon indicates that the Zn{sub 1-x}Fe{sub x}S (x = 0.1) nano-particles are superparamagnetic. The zero-field-cooled (ZFC) and field-cooled (FC) magnetization curves further reveal that the blocking temperature (T{sub B}) of the superparamagnetic behavior might be below 5 K.

  3. Investigation on structural and electrical properties of Fe doped ZnO nanoparticles synthesized by solution combustion method

    International Nuclear Information System (INIS)

    Ram, Mast; Bala, Kanchan; Sharma, Hakikat; Kumar, Arun; Negi, N. S.

    2016-01-01

    In the present study, nanoparticles of Fe doped zinc oxide (ZnO) [Zn_1_-_xFe_xO where x=0.0, 0.01, 0.02, 0.03 and 0.05] were prepared by cost effective solution combustion method. The powder X-ray diffractometry confirms the formation of single phase wurtzite structure. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to investigate the micrsostructure of Fe-doped ZnO nanoparticles. The DC electrical conductivity was found to increase with temperature and measurement was carried out in the temperature range of 300-473K. DC electrical conductivity increases with temperature and decreases with Fe doping concentration.

  4. Evaluation of Antioxidant and Cytotoxicity Activities of Copper Ferrite (CuFe2O4 and Zinc Ferrite (ZnFe2O4 Nanoparticles Synthesized by Sol-Gel Self-Combustion Method

    Directory of Open Access Journals (Sweden)

    Samikannu Kanagesan

    2016-08-01

    Full Text Available Spinel copper ferrite (CuFe2O4 and zinc ferrite (ZnFe2O4 nanoparticles were synthesized using a sol-gel self-combustion technique. The structural, functional, morphological and magnetic properties of the samples were investigated by Fourier transform infrared spectroscopy (FTIR, X-ray diffraction (XRD, Transmission electron microscopy (TEM and vibrating sample magnetometry (VSM. XRD patterns conform to the copper ferrite and zinc ferrite formation, and the average particle sizes were calculated by using a transmission electron microscope, the measured particle sizes being 56 nm for CuFe2O4 and 68 nm for ZnFe2O4. Both spinel ferrite nanoparticles exhibit ferromagnetic behavior with saturation magnetization of 31 emug−1 for copper ferrite (50.63 Am2/Kg and 28.8 Am2/Kg for zinc ferrite. Both synthesized ferrite nanoparticles were equally effective in scavenging 2,2-diphenyl-1-picrylhydrazyl hydrate (DPPH free radicals. ZnFe2O4 and CuFe2O4 nanoparticles showed 30.57% ± 1.0% and 28.69% ± 1.14% scavenging activity at 125 µg/mL concentrations. In vitro cytotoxicity study revealed higher concentrations (>125 µg/mL of ZnFe2O4 and CuFe2O4 with increased toxicity against MCF-7 cells, but were found to be non-toxic at lower concentrations suggesting their biocompatibility.

  5. A Novel DNA Nanosensor Based on CdSe/ZnS Quantum Dots and Synthesized Fe3O4 Magnetic Nanoparticles

    Directory of Open Access Journals (Sweden)

    Roozbeh Hushiarian

    2014-04-01

    Full Text Available Although nanoparticle-enhanced biosensors have been extensively researched, few studies have systematically characterized the roles of nanoparticles in enhancing biosensor functionality. This paper describes a successful new method in which DNA binds directly to iron oxide nanoparticles for use in an optical biosensor. A wide variety of nanoparticles with different properties have found broad application in biosensors because their small physical size presents unique chemical, physical, and electronic properties that are different from those of bulk materials. Of all nanoparticles, magnetic nanoparticles are proving to be a versatile tool, an excellent case in point being in DNA bioassays, where magnetic nanoparticles are often used for optimization of the hybridization and separation of target DNA. A critical step in the successful construction of a DNA biosensor is the efficient attachment of biomolecules to the surface of magnetic nanoparticles. To date, most methods of synthesizing these nanoparticles have led to the formation of hydrophobic particles that require additional surface modifications. As a result, the surface to volume ratio decreases and nonspecific bindings may occur so that the sensitivity and efficiency of the device deteriorates. A new method of large-scale synthesis of iron oxide (Fe3O4 nanoparticles which results in the magnetite particles being in aqueous phase, was employed in this study. Small modifications were applied to design an optical DNA nanosensor based on sandwich hybridization. Characterization of the synthesized particles was carried out using a variety of techniques and CdSe/ZnS core-shell quantum dots were used as the reporter markers in a spectrofluorophotometer. We showed conclusively that DNA binds to the surface of ironoxide nanoparticles without further surface modifications and that these magnetic nanoparticles can be efficiently utilized as biomolecule carriers in biosensing devices.

  6. Characterizations of diverse mole of pure and Ni-doped α-Fe2O3 synthesized nanoparticles through chemical precipitation route.

    Science.gov (United States)

    Sivakumar, S; Anusuya, D; Khatiwada, Chandra Prasad; Sivasubramanian, J; Venkatesan, A; Soundhirarajan, P

    2014-07-15

    In the present study, an attempt has been made for characterization and synthesis of pure and Ni-doped α-Fe2O3 (hematite) nanoparticles by chemical precipitation method. The synthesized products have been studied by X-ray diffraction (X-RD), Fourier transform infrared (FTIR) spectroscopy, UV-Vis diffuse reflectance spectroscopy (UV-Vis DRS), vibrating sample magnetometer (VSM) and scanning electron microscopy (SEM) techniques. The estimated average diameter of α-Fe2O3 nanoparticles were calculated by using the Debye-Scherrer equation and established as 31 nm. SEM micrographs showed the surface morphology as well as structures and particles distributions of synthesized samples. The UV-Vis DRS showed the indirect and direct band gap energies of pure and Ni-doped α-Fe2O3, these were reduced from 1.9847 to 1.52 eV and 2.0503 to 1.76 eV respectively. This result suggested the dopant enhanced the semiconducting behavior of iron oxide nanoparticles to an extent proportional to its nickel doped in the α-Fe2O3. Further, the magnetic properties of the pure and doped samples were investigated by vibrating sample magnetometer (VSM) and evaluated the information of pure and doped samples exhibited saturated hysteresis loop at room temperature, which is indicating that the weak ferromagnetism in nature of our synthesized samples. In addition, it has been found from the magnetization hysteresis curves of Ni-doping, resulting from increased the saturation of magnetization and reduced the coercivity of used samples. Therefore, the present study showed the reduction in band gap energies and coercive field for α-Fe2O3 nanoparticles due to nickel doped. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Improved battery performance using Pd nanoparticles synthesized on the surface of LiFePO4/C by ultrasound irradiation

    Science.gov (United States)

    Saliman, Muhammad Ali; Okawa, Hirokazu; Takai, Misaki; Ono, Yuki; Kato, Takahiro; Sugawara, Katsuyasu; Sato, Mineo

    2016-07-01

    LiFePO4 has been attracting interest as a cathode material for Li-ion batteries due to its high energy density, low cost, and eco-friendliness. The electrochemical performance of LiFePO4 is limited because it exhibits low Li-ion diffusivity and low electronic conductivity. Numerous solutions have been considered, such as carbon coating, which is widely known to improve the electronic conductivity of LiFePO4. The deposition of metal nanoparticles (NPs) on the surface of carbon-coated LiFePO4 further enhances the electronic conductivity. In this study, we deposited Pd NPs onto the surface of LiFePO4/C and investigated the resulting electrochemical performance. Sonochemical synthesis was used to prepare the metal NPs; the procedure did not require any surfactants and the reaction was rapid.

  8. Synthesized of PEG-6000 coated MgFe2O4 nanoparticles based on natural iron sand by co-precipitation method

    Science.gov (United States)

    Setiadi, E. A.; Simbolon, S.; Saputra, A. S. P.; Marlianto, E.; Djuhana; Kurniawan, C.; Yunus, M.; Sebayang, P.

    2018-02-01

    The polymer coated Magnesium Ferrite nanoparticles (MgFe2O4) based on natural iron sand, Mg(CH3COO)2.4H2O, and PEG-6000 have been successfully prepared by co-precipitation method. The mass variation of PEG-6000 content was from 0 to 12 gram. It was prepared at synthesize temperature of 70°C. The PEG coating reduced the effect of agglomeration, so the coercivity value can be closed to soft magnets. The nanoparticle of synthesized has MgFe2O4 single phase and cubic spinel structure. The bonding of MgFe2O4 and PEG-6000 as a coating material was confirmed by FTIR curve. The MgFe2O4 density decreased with the increasing of PEG 6000 content. On the other hand, the coercivity value was slightly reduced as the addition of PEG-6000, with the lowest value was obtained on 8 gram PEG content. The optimum condition is obtained at addition of 8 gram PEG 6000 to MgFe2O4, with coercivity, saturation, and remanence are 198.41 Oe, 52.53 emu/g, and 8.51 emu/g, respectively. So that, the sample is widely used as absorbance material of heavy metal.

  9. Size dependent electrical and magnetic properties of ZnFe2O4 nanoparticles synthesized by the combustion method: Comparison between aspartic acid and glycine as fuels

    International Nuclear Information System (INIS)

    Shanmugavani, A.; Kalai Selvan, R.; Layek, Samar; Sanjeeviraja, C.

    2014-01-01

    Using two different fuels such as aspartic acid and glycine, the spinel zinc ferrite nanoparticles were synthesized by the combustion method at different pH values. The thermochemical calculations for both the fuel assisted materials and its adiabatic flame temperature were calculated. The X-ray diffraction (XRD) pattern revealed the formation of single phase ZnFe 2 O 4 with high crystallinity. The characteristic functional groups of Fe3O and Zn3O were identified through FTIR analysis. Uniform size distribution of spherical particle in the average size range of 35–100 nm was inferred from SEM images. The room temperature DC conductivities of ZnFe 2 O 4 particles prepared by using aspartic and glycine are in the order of 10 −7 and 10 −8 respectively. The dielectric spectral analysis inferred that the obtained dielectric constant is high at low frequency and decreases with increase in frequency. This dielectric behavior is in accordance with the Maxwell–Wagner interfacial polarization. VSM and Mössbauer analysis revealed that the prepared material exhibits paramagnetic behavior and Fe 3+ state of iron content in ZnFe 2 O 4 at room temperature. - Highlights: • For the first time aspartic acid is used as a fuel to synthesize ZnFe 2 O 4 nanoparticles. • Theoretical adiabatic flame temperature for the formation of ZnFe 2 O 4 is calculated. • Individual spherical shape particles are achieved by combustion synthesis. • Enhanced room temperature conductivity for aspartic acid assisted particles are revealed. • Size dependent electrical and magnetic properties are demonstrated

  10. Crystal structure of superparamagnetic Mg0.2Ca0.8Fe2O4 nanoparticles synthesized by sol–gel method

    International Nuclear Information System (INIS)

    Escamilla-Pérez, A.M.; Cortés-Hernández, D.A.; Almanza-Robles, J.M.; Mantovani, D.; Chevallier, P.

    2015-01-01

    Powders of magnetic iron oxide nanoparticles (Mg 0.2 Ca 0.8 Fe 2 O 4 ) were prepared by a sol–gel method using ethylene glycol and nitrates of Fe, Ca and Mg as starting materials. Those powders were heat treated at different temperatures (573, 673, 773 and 873 K). In order to evaluate the effect of the heat treatment temperature on the nanoferrites properties, X-ray diffraction (XRD), vibrating sample magnetometry (VSM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) techniques were used. It was found that the reaction products exhibit nanometric sizes and superparamagnetic behavior. It is also demonstrated that, as the heat treatment temperature increases, the particle size and the saturation magnetization of the nanoferrites are increased. - Highlights: • Mg 0.2 Ca 0.8 Fe 2 O 4 superparamagnetic nanoparticles were successfully synthesized. • Particle average sizes of Ca–Mg ferrites were within the range of 8–25 nm. • The nanoferrite treated at 873 K showed a stoichiometry close to Mg 0.2 Ca 0.8 Fe 2 O 4 . • The heat treatment temperature has a strong effect on the crystal structure. • These nanoparticles are potential materials for magnetic hyperthermia

  11. Inverse spinel ZnFe2O4 nanoparticles synthesized by ion implantation and post-annealing: An investigation using X-ray spectroscopy and magneto-transport

    International Nuclear Information System (INIS)

    Zhou Shengqiang; Potzger, K.; Buerger, D.; Kuepper, K.; Helm, M.; Fassbender, J.; Schmidt, H.

    2009-01-01

    Noncrystalline ZnFe 2 O 4 has been investigated intensively due to the drastic difference in cation distribution compared with bulk materials. We previously synthesized ZnFe 2 O 4 nanoparticles by ion implantation and post-annealing [S. Zhou, K. Potzger, H. Reuther, G. Talut, F. Eichhorn, J. von Borany, W. Skorupa, M. Helm, J. Fassbender, J. Phys. D - Appl. Phys. 40 (2007) 964]. These ZnFe 2 O 4 nanocrystals are crystallographically oriented inside the ZnO matrix and show a hysteretic behavior upon magnetization reversal at 5 K. Their magnetic properties are explained by assuming that Fe 3+ ions partially occupy tetrahedral sites. In this paper an X-ray spectroscopic and magneto-transport investigation on ZnFe 2 O 4 nanocrystals in a ZnO matrix will be presented. The occupation of Fe 3+ at tetrahedral sites has been directly proved. A positive magnetoresistance (MR) effect is observed and is attributed to ordinary MR.

  12. Superparamagnetism and spin-glass like state for the MnFe2O4 nano-particles synthesized by the thermal decomposition method

    International Nuclear Information System (INIS)

    Gao Ruorui; Zhang Yue; Yu Wei; Xiong Rui; Shi Jing

    2012-01-01

    MnFe 2 O 4 nano-particles with an average size of about 7 nm were synthesized by the thermal decomposition method. Based on the magnetic hysteresis loops measured at different temperatures the temperature-dependent saturation magnetization (M S ) and coercivity (H C ) are determined. It is shown that above 20 K the temperature-dependence of the M S and H C indicates the magnetic behaviors in the single-domain nano-particles, while below 20 K, the change of the M S and H C indicates the freezing of the spin-glass like state on the surfaces. By measuring the magnetization–temperature (M–T) curves under the zero-field-cooling (ZFC) and field-cooling procedures at different applied fields, superparamagnetism behavior is also studied. Even though in the ZFC M–T curves peaks can be observed below 160 K, superparamagnetism does not appear until the temperature goes above 300 K, which is related with the strong inter-particle interaction. - Highlights: ► MnFe 2 O 4 nano-particles with size of 7 nm were prepared. ► The surface spin-glass like state is frozen below 20 K. ► The peaks in ZFC magnetization–temperature curves are observed below 160 K. ► The inter-particle interaction inhibits the superparamagnetism at room temperature.

  13. The effect of poly vinyl alcohol (PVA) surfactant on phase formation and magnetic properties of hydrothermally synthesized CoFe{sub 2}O{sub 4} nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Jalalian, M.; Mirkazemi, S.M., E-mail: mirkazemi@iust.ac.ir; Alamolhoda, S.

    2016-12-01

    Nanoparticles of CoFe{sub 2}O{sub 4} were synthesized by hydrothermal process at 190 °C with and without poly vinyl alcohol (PVA) addition using treatment durations of 1.5–6 h. The synthesized powders were characterized with X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscope (SEM), Field emission scanning electron microscope (FESEM) and vibration sample magnetometer (VSM) techniques. XRD results show presence of CoFe{sub 2}O{sub 4} as the main phase and Co{sub 3}O{sub 4} as the lateral phase in some samples. The results show that in the samples synthesized without PVA addition considerable amount of lateral phase is present after 3 h of hydrothermal treatment while with PVA addition this phase is undetectable in the XRD patterns of the sample synthesized at the same conditions. Microstructural studies represent increasing of particle size with increasing of hydrothermal duration and formation of coarser particles with PVA addition. The highest maximum magnetization (M{sub max}) values in both of the samples that were synthesized with and without PVA addition are about 59 emu/g that were obtained after 4.5 h of hydrothermal treatment. Intrinsic coercive field ({sub i}H{sub c}) value of the sample without PVA addition increases from 210 to 430 Oe. While with PVA addition the {sub i}H{sub c} value changes from 83 Oe to 493 Oe. The mechanism of changes in M{sub max} and {sub i}H{sub c} values has been explained. - Highlights: • Nanoparticles of CoFe{sub 2}O{sub 4} hydrothermally synthesized with and without PVA addition. • PVA addition facilitates formation of single phase cobalt ferrite. • Coarser particles would be obtained with PVA addition. • The highest M{sub max} values in the samples with and without PVA are equal to 59 emu/g. • The highest {sub i}H{sub c} values are equalt to 320 and 493 Oe without and with PVA respectively.

  14. Thermogravimetric and magneticproperties of Ni1-X Zn xFe2O4 nanoparticles synthesized by coprecipitation

    Directory of Open Access Journals (Sweden)

    Kandasamy Velmurugan

    2009-01-01

    Full Text Available Ni1-xZn xFe2O4 (x = 0 to 1 nanoparticles of size less than 9 nm were prepared by a chemical coprecipitation method which could be used for ferrofluid preparation. XRD, VSM and DTA-TG (STA were used to study the effect of variation in Zn substitution and its influence on particle size, magnetic properties such as M S, H C and Curie temperature, as well as on the water content. ICP was used to estimate Ni, Zn and Fe concentrations. The average crystallite size (DaveXR of the particles was found to decrease from 8.95 to 6.92 nm with increasing zinc substitution. The lattice constant (a o increased with increasing zinc substitution. The specific saturation magnetization (M S of the particles was measured at room temperature. Magnetic parameters such as M S, Hc, and Mr were found to decrease with increasing zinc substitution. Estimation of the water content, which varies the Zn concentration, plays a vital role for the correct determination of cation contents. The Curie temperature was found to decrease with increasing zinc substitution.

  15. Modeling and optimization of effective parameters on the size of synthesized Fe{sub 3}O{sub 4} superparamagnetic nanoparticles by coprecipitation technique using response surface methodology

    Energy Technology Data Exchange (ETDEWEB)

    Ghazanfari, Mohammad Reza, E-mail: Ghazanfari.mr@gmail.com [Department of Materials Science and Engineering, Ferdowsi University of Mashhad, 9177948974 Mashhad (Iran, Islamic Republic of); Kashefi, Mehrdad, E-mail: m-kashefi@um.ac.ir [Department of Materials Science and Engineering, Ferdowsi University of Mashhad, 9177948974 Mashhad (Iran, Islamic Republic of); Jaafari, Mahmoud Reza [Biotechnology Research Center, Nanotechnology Research Center, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad (Iran, Islamic Republic of)

    2016-05-01

    Generally, the statistical methods are defined as appropriate techniques to study the processes trends. In current research, the Fe{sub 3}O{sub 4} superparamagnetic nanoparticles were synthesized by coprecipitation method. In order to investigate the size properties of synthesized particles, the experimental design was done using central composite method (CCD) of response surface methodology (RSM) while the temperature, pH, and cation ratio of reaction were selected as influential factors. After particles synthesis based on designed runs, the different responses such as hydrodynamic size of particles (both freeze dried and air dried), size distribution, crystallite size, magnetic size, and zeta potential were evaluated by different techniques i.e. dynamic light scattering (DLS), X-ray diffraction (XRD), and vibrating sample magnetometer (VSM). Based on these results, the quadratic polynomial model was fitted for each response that could predict the response amounts. In following, the study of factors effects was carried out that showed the temperature, pH, and their interactions had higher effectiveness. Finally, by optimizing, it was clear that the minimum amounts of particle size (10.15 nm) and size distribution (13.01 nm) were reached in the minimum temperature (70 °C) and cation ratio (0.5) amounts and maximum pH amount (10.5). Moreover, the characterizations showed the particles size was about 10 nm while the amounts of M{sub s}, H{sub c}, and M{sub r} were equal to 60 (emu/g), 0.2 (Oe) and 0.22 (emu/g), respectively. - Highlights: • The Fe{sub 3}O{sub 4} nanoparticles were successfully synthesized by coprecipitation method. • By RSM technique, some predicted models were presented for particles size. • Temperature, pH and their interactions had most effectiveness on the particles size. • The drying techniques can effect on the size properties.

  16. Effects of processing parameters on the morphology, structure, and magnetic properties of Cu{sub 1−x}Fe{sub x}Cr{sub 2}Se{sub 4} nanoparticles synthesized with chemical methods

    Energy Technology Data Exchange (ETDEWEB)

    Ivantsov, R.D. [Kirensky Institute of Physics, Russian Academy of Sciences, Krasnoyarsk, 660036 (Russian Federation); Edelman, I.S., E-mail: ise@iph.krasn.ru [Kirensky Institute of Physics, Russian Academy of Sciences, Krasnoyarsk, 660036 (Russian Federation); Zharkov, S.M.; Velikanov, D.A. [Kirensky Institute of Physics, Russian Academy of Sciences, Krasnoyarsk, 660036 (Russian Federation); Siberian Federal University, Krasnoyarsk, 660041 (Russian Federation); Petrov, D.A. [Kirensky Institute of Physics, Russian Academy of Sciences, Krasnoyarsk, 660036 (Russian Federation); Ovchinnikov, S.G. [Kirensky Institute of Physics, Russian Academy of Sciences, Krasnoyarsk, 660036 (Russian Federation); Siberian Federal University, Krasnoyarsk, 660041 (Russian Federation); Lin, Chun-Rong [National Pingtung University, Pingtung City, Pingtung County, 90003, Taiwan (China); Li, Oksana [Siberian Federal University, Krasnoyarsk, 660041 (Russian Federation); National Pingtung University, Pingtung City, Pingtung County, 90003, Taiwan (China); Tseng, Yaw-Teng [National Pingtung University, Pingtung City, Pingtung County, 90003, Taiwan (China)

    2015-11-25

    Cu{sub 1−x}Fe{sub x}Cr{sub 2}Se{sub 4} nanoparticles with x = 0, 0.2, and 0.4 were synthesized via thermal decomposition of metal nitrate or chloride salts and selenium powder using different precursor compositions and processing details. Single crystalline nano-belts or nano-rods coexist in the synthesized powder samples with hexagon-shaped plates in dependence on the precursor composition. The belts gathered into conglomerates forming “hierarchical” particles. Visible magnetic circular dichroism (MCD) of Cu{sub 1−x}Fe{sub x}Cr{sub 2}Se{sub 4} nanoparticles embedded into a transparent matrix was investigated for the first time. The similarity of the MCD spectra of all samples showed the similarity of the nanoparticles electronic structure independent of their morphology. Basing on the MCD spectral maxima characteristics, electron transitions from the ground to the excited states were identified with the help of the conventional band theory and the multi-electron approach. - Highlights: • Single crystalline Cu{sub 1−x}Fe{sub x}Cr{sub 2}Se{sub 4} nanoparticles with x = 0, 0.2, 0.4 were synthesized. • Correlation between synthesis conditions and nanoparticles morphology were obtained. • The nanoparticles magnetization behavior was studied. • Visible MCD of the Cu{sub 1−x}Fe{sub x}Cr{sub 2}Se{sub 4} nanoparticles were studied for the first time.

  17. Method of synthesizing tungsten nanoparticles

    Science.gov (United States)

    Thoma, Steven G; Anderson, Travis M

    2013-02-12

    A method to synthesize tungsten nanoparticles has been developed that enables synthesis of nanometer-scale, monodisperse particles that can be stabilized only by tetrahydrofuran. The method can be used at room temperature, is scalable, and the product concentrated by standard means. Since no additives or stabilizing surfactants are required, this method is particularly well suited for producing tungsten nanoparticles for dispersion in polymers. If complete dispersion is achieved due to the size of the nanoparticles, then the optical properties of the polymer can be largely maintained.

  18. Optical and magnetic properties of La{sub 1−x}Ga{sub x}FeO{sub 3} nanoparticles synthesized by polymerization complex method

    Energy Technology Data Exchange (ETDEWEB)

    Hunpratub, Sitchai [Department of Physics, Faculty of Science, Udon Thani Rajabhat University, Udon Thani 41000 (Thailand); Karaphun, Attaphol [Nanotec-KKU Center of Excellence on Advanced Nanomaterials for Energy Production and Storage, Khon Kaen 40002 (Thailand); Phokha, Sumalin [Department of Physics, Faculty of Science, Udon Thani Rajabhat University, Udon Thani 41000 (Thailand); Swatsitang, Ekaphan, E-mail: ekaphan@kku.ac.th [Integrated Nanotechnology Research Center, Department of Physics, Faculty of Science, Khon Kaen University, Khon Kaen 40002 (Thailand); Nanotec-KKU Center of Excellence on Advanced Nanomaterials for Energy Production and Storage, Khon Kaen 40002 (Thailand)

    2016-09-01

    Graphical abstract: This figure shows the hysteresis loops of LaFeO{sub 3} and La{sub 0.6}Ga{sub 0.4}FeO{sub 3} nanoparticles with corresponding TEM images. Undoped sample exhibits antiferromagnetic behavior, whereas doped sample becomes ferromagnetic material. Particle sizes estimated by TEM are decreased from 70.2 ± 4.5 to 21.4 ± 8.5 nm with increasing Ga content. The decrease of particle size causes the disordering spins at the surface of particle which can induce a net magnetic moment and significantly enhance the magnetization (M), coercive field (H{sub c}) and remanent magnetization (M{sub r}). - Highlights: • Ga-doped LaFeO{sub 3} nanoparticles prepared by polymerization complex were studied. • Lattice, crystallite and particle size of sample decrease with increasing Ga content. • Decreasing of the lattice can distort the structure and enhance magnetic properties. • Optical band gaps of LaGaFeO{sub 3} nanoparticles are also decreased. • RT-FM of LaGaFeO{sub 3} nanoparticle is due to the disordering spins at surface particle. - Abstract: La{sub 1−x}Ga{sub x}FeO{sub 3} (x = 0.0, 0.1, 0.2, 0.3 and 0.4) nanoparticles were synthesized by polymerization complex method. X-ray diffraction (XRD) results reveal a pure orthorhombic phase structure. Increasing of Ga content, resulting in the decrease of average crystallite sizes calculated by XRD from 58.4 ± 5.9 to 13.4 ± 4.3 nm and the average particle sizes estimated by transmission electron microscope (TEM) images from 70.2 ± 4.5 to 21.4 ± 8.5 nm. The optical band gaps determined by UV–vis spectra showed a redshift from 2.145 to 1.954 eV that originates from surface effect caused by Ga substitution. The magnetic properties were investigated using a vibrating sample magnetometer (VSM). The room temperature hysteresis loops of La{sub 1–x}Ga{sub x}FeO{sub 3} nanopowders indicate the antiferromagnetic behavior of pure sample and all doped samples of ferromagnetic behavior with the enhancement of

  19. Defluoridation technology for drinking water and tea by green synthesized Fe3O4/Al2O3 nanoparticles coated polyurethane foams for rural communities.

    Science.gov (United States)

    Kumari, Sonu; Khan, Suphiya

    2017-08-14

    Fluoride (F) contaminated ground water poses a serious public health concern to rural population with unaffordable purification technologies. Therefore, development of a cost-effective, portable, environment and user-friendly defluoridation technique is imperative. In the present study, we report on the development of a green and cost-effective method that utilizes Fe 3 O 4 and Al 2 O 3 nanoparticles (NPs) that were synthesized using jojoba defatted meal. These NPs were impregnated on to polyurethane foam (PUF) and made into tea infusion bags. The Al 2 O 3 NPs-PUF displayed a higher water defluoridation capacity of 43.47 mg g -1 of F as compared to 34.48 mg g -1 of F with Fe 3 O 4 NPs-PUF. The synthesized Al 2 O 3 -PUF infusion bags removed the F that was under the permissible limit of 1.5 mg L -1 . The sorption experiments were conducted to verify the effect of different parameters such as pH, contact time, size of PUF and initial F concentration. The different properties of adsorbent were characterized using a combination of FESEM, EDX, XRD and FTIR techniques, respectively. The calculated total cost per NPs-PUF pouch developed is as low as US $0.05, which makes the technology most suitable for rural communities. This paper will be beneficial for researchers working toward further improvement in water purification technologies.

  20. Superparamagnetism and spin-glass like state for the MnFe{sub 2}O{sub 4} nano-particles synthesized by the thermal decomposition method

    Energy Technology Data Exchange (ETDEWEB)

    Gao Ruorui [Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, School of Physics and Technology, Wuhan University, Wuhan 430072 (China); Zhang Yue, E-mail: yue-zhang@mail.hust.edu.cn [Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, School of Physics and Technology, Wuhan University, Wuhan 430072 (China); Department of Electric Science and Technology, Huazhong University of Science and Technology, Wuhan 430074 (China); Yu Wei [Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, School of Physics and Technology, Wuhan University, Wuhan 430072 (China); Xiong Rui [Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, School of Physics and Technology, Wuhan University, Wuhan 430072 (China); Key Laboratory for the Green Preparation and Application of Functional Materials of Ministry of Education, Hubei University, Wuhan 430062 (China); Shi Jing [Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, School of Physics and Technology, Wuhan University, Wuhan 430072 (China); Key Laboratory for the Green Preparation and Application of Functional Materials of Ministry of Education, Hubei University, Wuhan 430062 (China); International Center for Material Physics, Shen Yang 110015 (China)

    2012-08-15

    MnFe{sub 2}O{sub 4} nano-particles with an average size of about 7 nm were synthesized by the thermal decomposition method. Based on the magnetic hysteresis loops measured at different temperatures the temperature-dependent saturation magnetization (M{sub S}) and coercivity (H{sub C}) are determined. It is shown that above 20 K the temperature-dependence of the M{sub S} and H{sub C} indicates the magnetic behaviors in the single-domain nano-particles, while below 20 K, the change of the M{sub S} and H{sub C} indicates the freezing of the spin-glass like state on the surfaces. By measuring the magnetization-temperature (M-T) curves under the zero-field-cooling (ZFC) and field-cooling procedures at different applied fields, superparamagnetism behavior is also studied. Even though in the ZFC M-T curves peaks can be observed below 160 K, superparamagnetism does not appear until the temperature goes above 300 K, which is related with the strong inter-particle interaction. - Highlights: Black-Right-Pointing-Pointer MnFe{sub 2}O{sub 4} nano-particles with size of 7 nm were prepared. Black-Right-Pointing-Pointer The surface spin-glass like state is frozen below 20 K. Black-Right-Pointing-Pointer The peaks in ZFC magnetization-temperature curves are observed below 160 K. Black-Right-Pointing-Pointer The inter-particle interaction inhibits the superparamagnetism at room temperature.

  1. Statistical approach of synthesize CoFe{sub 2}O{sub 4} nanoparticles to optimize their characteristics using response surface methodology

    Energy Technology Data Exchange (ETDEWEB)

    Shams, S. Fatemeh, E-mail: f.shams@fz-juelich.de [Department of Materials Science and Engineering, Ferdowsi University of Mashhad, 9177948974 Mashhad (Iran, Islamic Republic of); Peter Grünberg Institute (PGI-6), Jülich Research Centre, 52425 Jülich (Germany); Kashefi, Mehrdad, E-mail: m-kashefi@um.ac.ir [Department of Materials Science and Engineering, Ferdowsi University of Mashhad, 9177948974 Mashhad (Iran, Islamic Republic of); Schmitz-Antoniak, Carolin [Peter Grünberg Institute (PGI-6), Jülich Research Centre, 52425 Jülich (Germany)

    2017-06-15

    Highlights: • The CoFe{sub 2}O{sub 4} nanoparticles were successfully synthesized by coprecipitation method. • By RSM technique, some predicted models were presented for particles size. • Temperature, pH and their interactions had most effectiveness on the particles size. • The reduction agent type can effect on the size properties. • The mixing order of components can effect on the size properties. - Abstract: The performance of magnetic nanoparticles in different applications is severely depended on their size characteristics, so the study of effective parameters on these properties can play significant roles in qualifications of nanoparticles. In present work, some important factors on size features of CoFe{sub 2}O{sub 4} superparamagnetic nanoparticles include the mixing order of synthesis components, the utilized reduction agents, stabilization process, and chelating mechanisms were investigated. Moreover, in order to optimize several influential factors such as the temperature, pH, and cation ratio of reaction, the experimental design was done by using central composite design method of response surface methodology. The simultaneous effects on the particles size and their size distribution were investigated by different methods i.e. dynamic light scattering, X-ray diffraction, Fourier transform inferred spectroscopy, vibration sample magnetometer, and transmission electron microscopy. Results demonstrated the mixing order of reduction agent to salt solution and also the employing of NH{sub 4}OH as a reduction agent could cause to significant decreasing of particles size and size distribution. Furthermore, the nitric acid could stabilize and chelate nanoparticles more appropriate than citric acid. Based on the optimization results, the quadratic polynomial models were fitted on the responses which could predict their amounts, while temperature, pH, and their interactions had higher effectiveness. In addition, the optimum amounts of particle size (14

  2. Exploring the Room-Temperature Ferromagnetism and Temperature-Dependent Dielectric Properties of Sr/Ni-Doped LaFeO3 Nanoparticles Synthesized by Reverse Micelle Method

    Science.gov (United States)

    Naseem, Swaleha; Khan, Shakeel; Husain, Shahid; Khan, Wasi

    2018-03-01

    This paper reports the thermal, microstructural, dielectric and magnetic properties of La0.75Sr0.25Fe0.65Ni0.35O3 nanoparticles (NPs) synthesized via reverse micelle technique. The thermogravimetric analysis of as-prepared NPs confirmed a good thermal stability of the sample. Powder x-ray diffraction data analyzed with a Rietveld refinement technique revealed single-phase and orthorhombic distorted perovskite crystal structure of the NPs having Pbnm space group. The transmission electron microscopy images show the crystalline nature and formation of nanostructures with a fairly uniform distribution of particles throughout the sample. Temperature-dependent dielectric properties of the NPs in accordance with the Kramers-Kronig transformation (KKT) model, universal dielectric response model and jump relaxation model have been discussed. Electrode or interface polarization is likely the cause of the observed dielectric behavior. Due to grain boundaries and Schottky barriers of the metallic electrodes of semiconductors, the depletion region is observed, which gives rise to Maxwell-Wagner relaxation and hence high dielectric constants. Magnetic studies revealed the ferromagnetic nature of the prepared NPs upon Sr and Ni doping in LaFeO3 perovskite at room temperature. Therefore, these NPs could be a potential candidate as electrode material in solid oxide fuel cells.

  3. Phase formation, morphology and magnetic properties of MgFe{sub 2}O{sub 4} nanoparticles synthesized by hydrothermal technique

    Energy Technology Data Exchange (ETDEWEB)

    Nonkumwong, Jeeranan [Department of Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Ananta, Supon [Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Jantaratana, Pongsakorn [Department of Physics, Faculty of Science, Kasetsart University, Bangkok 11900 (Thailand); Phumying, Santi; Maensiri, Santi [Advanced Materials Physics Laboratory (Amp.), School of Physics, Institute of Science, Suranaree University of Technology, Nakhon Ratchasima 30000 (Thailand); Srisombat, Laongnuan, E-mail: slaongnuan@yahoo.com [Department of Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand)

    2015-05-01

    In the present work, the processing conditions for obtaining monodispersed magnesium ferrite (MgFe{sub 2}O{sub 4}) nanoparticles with the desired morphology and relatively high saturation magnetization via hydrothermal technique were developed. For the first time, the effects of base type and reaction conditions (i.e. temperature and time) on phase formation, morphology and magnetic properties of the obtained products were determined by using a combination of XRD, TEM/EDX and VSM techniques. It is seen that the saturation magnetization of the particles can be increased by employing lower reaction temperature and/or shorter reaction time, while narrow size distribution of the particles can be maintained. In addition, it was found that pure phase of superparamagnetic MgFe{sub 2}O{sub 4} nanoparticles with the smallest size of about 65 nm was obtained by using CH{sub 3}COONa as a base at 180 °C for 14 h. - Highlights: • Preparation of MgFe{sub 2}O{sub 4} nanoparticles by hydrothermal method. • Effects of base and reaction conditions on formation and morphology MgFe{sub 2}O{sub 4} particles. • Producing the 65 nm MgFe{sub 2}O{sub 4} nanoparticles with superparamagnetic property.

  4. Enzymes immobilization on Fe 3O 4-gold nanoparticles

    Science.gov (United States)

    Kalska-Szostko, B.; Rogowska, M.; Dubis, A.; Szymański, K.

    2012-01-01

    In the present study Fe3O4 magnetic nanoparticles were synthesized by coprecipitation of Fe2+ and Fe3+ from chlorides. In the next step magnetite-gold core-shell nanoparticles were synthesized from HAuCl4 using an ethanol as a reducing agent. Finally, magnetic nanoparticles were functionalized by hexadecanethiol. The immobilization of biological molecules (trypsin and glucose oxidase) to the thiol-modified and unmodified magnetite-gold nanoparticles surface was tested. The resulting nanoparticles were characterized by infrared spectroscopy, differential scanning calorimetry, Mössbauer spectroscopy and transmission electron microscopy.

  5. Synthesize and characterization of a novel anticorrosive cobalt ferrite nanoparticles dispersed in silica matrix (CoFe2O4-SiO2) to improve the corrosion protection performance of epoxy coating

    International Nuclear Information System (INIS)

    Gharagozlou, M.; Ramezanzadeh, B.; Baradaran, Z.

    2016-01-01

    Highlights: • An anticorrosive cobalt ferrite nanopigment dispersed in silica matrix was synthesized. • The nanopigment showed proper inhibition performance in solution study. • The nanopigment significantly improved the corrosion resistance of the epoxy coating. - Abstract: This study aimed at studying the effect of an anticorrosive nickel ferrite nanoparticle dispersed in silica matrix (NiFe 2 O 4 -SiO 2 ) on the corrosion protection properties of steel substrate. NiFe 2 O 4 and NiFe 2 O 4 -SiO 2 nanopigments were synthesized and then characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and transmission electron microscope (TEM). Then, 1 wt.% of nanopigments was dispersed in an epoxy coating and the resultant nanocomposites were applied on the steel substrates. The corrosion inhibition effects of nanopigments were tested by an electrochemical impedance spectroscopy (EIS) and salt spray test. Results revealed that dispersing nickel ferrite nanoparticles in a silica matrix (NiFe 2 O 4 -SiO 2 ) resulted in the enhancement of the nanopigment dispersion in the epoxy coating matrix. Inclusion of 1 wt.% of NiFe 2 O 4 -SiO 2 nanopigment into the epoxy coating enhanced its corrosion protection properties before and after scratching.

  6. Biosynthesis of silver nanoparticles synthesized by Aspergillus

    Indian Academy of Sciences (India)

    In the present study, biosynthesis of silver nanoparticles and its antioxidant, antimicrobial and cytotoxic activities were investigated. Silver nanoparticles were extracellularly synthesized using Aspergillus flavus and the formation of nanoparticles was observed after 72 h of incubation. The results recorded from colour ...

  7. Magnetic properties of Co{sub 1−x}Zn{sub x}Fe{sub 2}O{sub 4} spinel ferrite nanoparticles synthesized by starch-assisted sol–gel autocombustion method and its ball milling

    Energy Technology Data Exchange (ETDEWEB)

    Yadav, Raghvendra Singh, E-mail: yadav@fch.vutbr.cz [Materials Research Centre, Brno University of Technology, Purkyňova 464/118, 61200 Brno (Czech Republic); Havlica, Jaromir [Materials Research Centre, Brno University of Technology, Purkyňova 464/118, 61200 Brno (Czech Republic); Hnatko, Miroslav; Šajgalík, Pavol [Institute of Inorganic Chemistry, Slovak Academy of Sciences, Dúbravská cesta 9, SK-845 36 Bratislava (Slovakia); Alexander, Cigáň [Institute of Measurement Science, Slovak Academy of Sciences, Dúbravská cesta 9, SK-841 04 Bratislava (Slovakia); Palou, Martin; Bartoníčková, Eva; Boháč, Martin; Frajkorová, Františka; Masilko, Jiri; Zmrzlý, Martin; Kalina, Lukas; Hajdúchová, Miroslava; Enev, Vojtěch [Materials Research Centre, Brno University of Technology, Purkyňova 464/118, 61200 Brno (Czech Republic)

    2015-03-15

    In this article, Co{sub 1−x}Zn{sub x}Fe{sub 2}O{sub 4} (x=0.0 and 0.5) spinel ferrite nanoparticles were achieved at 800 °C by starch-assisted sol–gel autocombustion method. To further reduce the particle size, these synthesized ferrite nanoparticles were ball-milled for 2 h. X-ray diffraction patterns demonstrated single phase formation of Co{sub 1−x}Zn{sub x}Fe{sub 2}O{sub 4} (x=0.0 and 0.5) spinel ferrite nanoparticles. FE-SEM analysis indicated the nanosized spherical particles formation with spherical morphology. The change in Raman modes and relative intensity were observed due to ball milling and consequently decrease of particle size and cationic redistribution. An X-ray Photoelectron Spectroscopy (XPS) result indicated that Co{sup 2+}, Zn{sup 2+} and Fe{sup 3+} exist in octahedral and tetrahedral sites. The cationic redistribution of Zn{sup 2+} and consequently Fe{sup 3+} occurred between octahedral and tetrahedral sites after ball-milling. The change in saturation magnetization (M{sub s}) and coercivity (H{sub c}) with decrease of nanocrystalline size and distribution of cations in spinel ferrite were observed. - Highlights: • Co{sub 1−x}Zn{sub x}Fe{sub 2}O{sub 4} spinel ferrite nanoparticles. • Starch-assisted sol–gel auto-combustion method. • Effect of ball-milling on particle size and cation distribution. • Magnetic property dependent on cations and particle size.

  8. Size dependent electrical and magnetic properties of ZnFe{sub 2}O{sub 4} nanoparticles synthesized by the combustion method: Comparison between aspartic acid and glycine as fuels

    Energy Technology Data Exchange (ETDEWEB)

    Shanmugavani, A. [Solid State Ionics and Energy Devices Laboratory, Department of Physics, Bharathiar University, Coimbatore 641046 (India); Kalai Selvan, R., E-mail: selvankram@buc.edu.in [Solid State Ionics and Energy Devices Laboratory, Department of Physics, Bharathiar University, Coimbatore 641046 (India); Layek, Samar [Department of Physics, Indian institute of Technology, Kanpur 208016 (India); Sanjeeviraja, C. [Department of Physics, Alagappa Chettiar College of Engineering and Technology, Karaikudi- 630 004, Tamil Nadu (India)

    2014-03-15

    Using two different fuels such as aspartic acid and glycine, the spinel zinc ferrite nanoparticles were synthesized by the combustion method at different pH values. The thermochemical calculations for both the fuel assisted materials and its adiabatic flame temperature were calculated. The X-ray diffraction (XRD) pattern revealed the formation of single phase ZnFe{sub 2}O{sub 4} with high crystallinity. The characteristic functional groups of Fe3O and Zn3O were identified through FTIR analysis. Uniform size distribution of spherical particle in the average size range of 35–100 nm was inferred from SEM images. The room temperature DC conductivities of ZnFe{sub 2}O{sub 4} particles prepared by using aspartic and glycine are in the order of 10{sup −7} and 10{sup −8} respectively. The dielectric spectral analysis inferred that the obtained dielectric constant is high at low frequency and decreases with increase in frequency. This dielectric behavior is in accordance with the Maxwell–Wagner interfacial polarization. VSM and Mössbauer analysis revealed that the prepared material exhibits paramagnetic behavior and Fe{sup 3+} state of iron content in ZnFe{sub 2}O{sub 4} at room temperature. - Highlights: • For the first time aspartic acid is used as a fuel to synthesize ZnFe{sub 2}O{sub 4} nanoparticles. • Theoretical adiabatic flame temperature for the formation of ZnFe{sub 2}O{sub 4} is calculated. • Individual spherical shape particles are achieved by combustion synthesis. • Enhanced room temperature conductivity for aspartic acid assisted particles are revealed. • Size dependent electrical and magnetic properties are demonstrated.

  9. Crystal structure of superparamagnetic Mg{sub 0.2}Ca{sub 0.8}Fe{sub 2}O{sub 4} nanoparticles synthesized by sol–gel method

    Energy Technology Data Exchange (ETDEWEB)

    Escamilla-Pérez, A.M., E-mail: angel.mep@gmail.com [Cinvestav-Unidad Saltillo, Industria Metalúrgica No. 1062, Parque Industrial Saltillo-Ramos Arizpe, C.P. 25900, Ramos Arizpe, Coahuila (Mexico); Cortés-Hernández, D.A., E-mail: dora.cortes@cinvestav.edu.mx [Cinvestav-Unidad Saltillo, Industria Metalúrgica No. 1062, Parque Industrial Saltillo-Ramos Arizpe, C.P. 25900, Ramos Arizpe, Coahuila (Mexico); Almanza-Robles, J.M. [Cinvestav-Unidad Saltillo, Industria Metalúrgica No. 1062, Parque Industrial Saltillo-Ramos Arizpe, C.P. 25900, Ramos Arizpe, Coahuila (Mexico); Mantovani, D.; Chevallier, P. [Laboratory for Biomaterials and Bioengineering, Department of Materials Engineering and University Hospital Research Center, Laval University, Quebec City, QC (Canada)

    2015-01-15

    Powders of magnetic iron oxide nanoparticles (Mg{sub 0.2}Ca{sub 0.8}Fe{sub 2}O{sub 4}) were prepared by a sol–gel method using ethylene glycol and nitrates of Fe, Ca and Mg as starting materials. Those powders were heat treated at different temperatures (573, 673, 773 and 873 K). In order to evaluate the effect of the heat treatment temperature on the nanoferrites properties, X-ray diffraction (XRD), vibrating sample magnetometry (VSM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) techniques were used. It was found that the reaction products exhibit nanometric sizes and superparamagnetic behavior. It is also demonstrated that, as the heat treatment temperature increases, the particle size and the saturation magnetization of the nanoferrites are increased. - Highlights: • Mg{sub 0.2}Ca{sub 0.8}Fe{sub 2}O{sub 4} superparamagnetic nanoparticles were successfully synthesized. • Particle average sizes of Ca–Mg ferrites were within the range of 8–25 nm. • The nanoferrite treated at 873 K showed a stoichiometry close to Mg{sub 0.2}Ca{sub 0.8}Fe{sub 2}O{sub 4}. • The heat treatment temperature has a strong effect on the crystal structure. • These nanoparticles are potential materials for magnetic hyperthermia.

  10. nanoparticles synthesized by citrate precursor m

    African Journals Online (AJOL)

    user

    (M=Co, Cu) nanoparticles synthesized by citrate precursor method ... The structural characterization was carried out using an X-ray Diffractometer (Rikagu Miniflex, Japan) ..... His current area of interest includes magnetic nanomaterials.

  11. Synthesizing nanoparticles by mimicking nature

    Science.gov (United States)

    As particulate matter with at least one dimension that is less than 100 nm, nanoparticles are the minuscule building blocks of new commercial products and consumer materials in the emerging field of nanotechnology. Nanoparticles are being discovered and introduced in the marketpl...

  12. Synthesis and magnetic properties of prussian blue modified Fe nanoparticles

    International Nuclear Information System (INIS)

    Arun, T.; Prakash, K.; Justin Joseyphus, R.

    2013-01-01

    Fe nanoparticles are prepared using a unique polyol process and modified with prussian blue (PB) at various concentrations. The presence of PB in the Fe nanoparticles are confirmed from thermal, Fourier transform infrared spectroscopy and electron microscopic analyses. The prussian blue existed on ;the surface of the nanoparticles when the concentration is 200 μM and in excess with 1000 μM. ;Fe nanoparticles are reduced in size using Pt as nucleating agent and modified with the optimum concentration of PB. The saturation magnetization decreases with the concentration of PB whereas the coercivity is influenced by the size of the Fe nanoparticles. The presence of oxide layer in Fe nanoparticles helps in the surface modification with PB. The Fe nanoparticles of particle size 53 nm modified with 200 μM of PB showed a saturation magnetization of 110 emu/g. The magnetic properties suggest that the PB modified Fe nanoparticles are better candidates for detoxification applications. - Highlights: • Fe nanoparticles surface modified with prussian blue (PB) were synthesized. • Optimum PB concentration on size reduced Fe showed better magnetic properties. • Coercivity decreased with increasing concentration of PB. • Fe-PB nanoparticles could be used for detoxification applications

  13. Structural transformations of mechanically induced top-down approach BaFe{sub 12}O{sub 19} nanoparticles synthesized from high crystallinity bulk materials

    Energy Technology Data Exchange (ETDEWEB)

    Low, Zhi Huang [Institute of Advanced Technology, Universiti Putra Malaysia, 43400 Serdang, Selangor Darul Ehsan (Malaysia); Chen, Soo Kien [Institute of Advanced Technology, Universiti Putra Malaysia, 43400 Serdang, Selangor Darul Ehsan (Malaysia); Department of Physics, Faculty of Science, University Putra Malaysia, 43400 Serdang, Selangor Darul Ehsan (Malaysia); Ismail, Ismayadi, E-mail: kayzen@gmail.com [Institute of Advanced Technology, Universiti Putra Malaysia, 43400 Serdang, Selangor Darul Ehsan (Malaysia); Tan, Kim Song [Advanced Imaging Centre, Malaysian Rubber Board, RRIM Sungai Buloh, 47000 Selangor (Malaysia); Liew, J.Y.C. [Department of Physics, Faculty of Science, University Putra Malaysia, 43400 Serdang, Selangor Darul Ehsan (Malaysia)

    2017-05-01

    In this work, a top-down approach was applied to high crystallinity BaFe{sub 12}O{sub 19} bulks, breaking them into smaller nanoparticles by mechanochemical route. The effects of milling time, reaction mechanisms and structural information were investigated. Interestingly, three distinct stages of the mechanochemical mechanism were observed. The XRD results indicated that the BaFe{sub 12}O{sub 19} phase existed even though the mechanical energy had induced the formation of an amorphous phase in the material. The average crystallite size decreased during the first stage and the intermediate stage, and increased during the final stage of the mechanical alloying. A Rietveld refinement analysis suggested the deformation of a mechanically-triggered polyhedral in the magnetoplumbite structure. FESEM micrographs indicated that fragmentation predominated during the first and intermediate stages, until a steady equilibrium state was achieved at in the final stage, where a narrow particle size distribution was observed. HRTEM micrographs suggested the formation of a non-uniform nanostructure shell surrounding the ordered core materials at the edge-interface region. The thickness of the amorphous surface layer extended up to 12 nm during the first and intermediate stages, and diminished to approximately 3 nm after 20 h milling. VSM results showed a mixture of ferromagnetic, superparamagnetic, and paramagnetic behaviours. However, different magnetic behaviours predominated at different milling time, which strongly related to the defects, distorted polyhedra, and non-equilibrium amorphous layers of the material. - Highlights: • Nanoparticles of BaFe{sub 12}O{sub 19} are successfully prepared. • Morphological and structural properties rely on mechanochemical mechanism. • Three stages of mechanochemical mechanism was observed. • Core shell structures (3–12 nm) was found during by extending the milling time. • Magnetic properties were strongly related with the

  14. Structural transformations of mechanically induced top-down approach BaFe12O19 nanoparticles synthesized from high crystallinity bulk materials

    International Nuclear Information System (INIS)

    Low, Zhi Huang; Chen, Soo Kien; Ismail, Ismayadi; Tan, Kim Song; Liew, J.Y.C.

    2017-01-01

    In this work, a top-down approach was applied to high crystallinity BaFe 12 O 19 bulks, breaking them into smaller nanoparticles by mechanochemical route. The effects of milling time, reaction mechanisms and structural information were investigated. Interestingly, three distinct stages of the mechanochemical mechanism were observed. The XRD results indicated that the BaFe 12 O 19 phase existed even though the mechanical energy had induced the formation of an amorphous phase in the material. The average crystallite size decreased during the first stage and the intermediate stage, and increased during the final stage of the mechanical alloying. A Rietveld refinement analysis suggested the deformation of a mechanically-triggered polyhedral in the magnetoplumbite structure. FESEM micrographs indicated that fragmentation predominated during the first and intermediate stages, until a steady equilibrium state was achieved at in the final stage, where a narrow particle size distribution was observed. HRTEM micrographs suggested the formation of a non-uniform nanostructure shell surrounding the ordered core materials at the edge-interface region. The thickness of the amorphous surface layer extended up to 12 nm during the first and intermediate stages, and diminished to approximately 3 nm after 20 h milling. VSM results showed a mixture of ferromagnetic, superparamagnetic, and paramagnetic behaviours. However, different magnetic behaviours predominated at different milling time, which strongly related to the defects, distorted polyhedra, and non-equilibrium amorphous layers of the material. - Highlights: • Nanoparticles of BaFe 12 O 19 are successfully prepared. • Morphological and structural properties rely on mechanochemical mechanism. • Three stages of mechanochemical mechanism was observed. • Core shell structures (3–12 nm) was found during by extending the milling time. • Magnetic properties were strongly related with the mechanically induced defects.

  15. Biogenic synthesized nanoparticles and their applications

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Abhijeet, E-mail: abhijeet.singh@jaipur.manipal.edu; Sharma, Madan Mohan [Manipal University Jaipur (India)

    2016-05-06

    In the present scenario, there are growing concerns over the potential impacts of bioengineered nanoparticles in the health sector. However, our understanding of how bioengineered nanoparticles may affect organisms within natural ecosystems, lags far behind our rapidly increasing ability to engineer novel nanoparticles. To date, research on the biological impacts of bioengineered nanoparticles has primarily consisted of controlled lab studies of model organisms with single species in culture media. Here, we described a cost effective and environment friendly technique for green synthesis of silver nanoparticles. Silver nanoparticles were successfully synthesized from 1 mM AgNO{sub 3} via a green synthesis process using leaf extract as reducing as well as capping agent. Nanoparticles were characterized with the help of UV–vis absorption spectroscopy, X-ray diffraction and TEM analysis which revealed the size of nanoparticles of 30-40 nm size. Further the nanoparticles synthesized by green route are found highly toxic against pathogenic bacteria and plant pathogenic fungi viz. Escherichia coli, Pseudomonas syringae and Sclerotiniasclerotiorum. The most important outcome of this work will be the development of value-added products and protection of human health from pathogens viz., bacteria, virus, fungi etc.

  16. Biogenic synthesized nanoparticles and their applications

    International Nuclear Information System (INIS)

    Singh, Abhijeet; Sharma, Madan Mohan

    2016-01-01

    In the present scenario, there are growing concerns over the potential impacts of bioengineered nanoparticles in the health sector. However, our understanding of how bioengineered nanoparticles may affect organisms within natural ecosystems, lags far behind our rapidly increasing ability to engineer novel nanoparticles. To date, research on the biological impacts of bioengineered nanoparticles has primarily consisted of controlled lab studies of model organisms with single species in culture media. Here, we described a cost effective and environment friendly technique for green synthesis of silver nanoparticles. Silver nanoparticles were successfully synthesized from 1 mM AgNO_3 via a green synthesis process using leaf extract as reducing as well as capping agent. Nanoparticles were characterized with the help of UV–vis absorption spectroscopy, X-ray diffraction and TEM analysis which revealed the size of nanoparticles of 30-40 nm size. Further the nanoparticles synthesized by green route are found highly toxic against pathogenic bacteria and plant pathogenic fungi viz. Escherichia coli, Pseudomonas syringae and Sclerotiniasclerotiorum. The most important outcome of this work will be the development of value-added products and protection of human health from pathogens viz., bacteria, virus, fungi etc.

  17. Interactions in γ-Fe2O3 and Fe3O4 nanoparticle systems

    International Nuclear Information System (INIS)

    Laha, S.S.; Tackett, R.J.; Lawes, G.

    2014-01-01

    We have investigated interaction effects in two different systems of iron oxide nanoparticles. Samples of γ-Fe 2 O 3 and Fe 3 O 4 nanoparticles were synthesized using a matrix-mediated precipitation reaction and a chemical co-precipitation technique respectively. The structural properties of these nanoparticles were studied using x-ray diffraction and transmission electron microscopy. We also used temperature dependent ac magnetic susceptibility measurements to carefully investigate the interactions among these nanoparticles. Our analysis showed that the characteristic interaction energy does not depend simply on the average spacing between the nanoparticles but is likely to be strongly influenced by the fluctuations in the nanoparticle distribution

  18. Mössbauer Studies of Core-Shell FeO/Fe3O4 Nanoparticles

    Science.gov (United States)

    Kamzin, A. S.; Valiullin, A. A.; Khurshid, H.; Nemati, Z.; Srikanth, H.; Phan, M. H.

    2018-02-01

    FeO/Fe3O4 nanoparticles were synthesized by thermal decomposition. Electron microscopy revealed that these nanoparticles were of the core-shell type and had a spherical shape with an average size of 20 nm. It was found that the obtained FeO/Fe3O4 nanoparticles had exchange coupling. The effect of anisotropy on the efficiency of heating (hyperthermic effect) of FeO/Fe3O4 nanoparticles by an external alternating magnetic field was examined. The specific absorption rate (SAR) of the studied nanoparticles was 135 W/g in the experiment with an external alternating magnetic field with a strength of 600 Oe and a frequency of 310 kHz. These data led to an important insight: the saturation magnetization is not the only factor governing the SAR, and the efficiency of heating of magnetic FeO/Fe3O4 nanoparticles may be increased by enhancing the effective anisotropy. Mössbauer spectroscopy of the phase composition of the synthesized nanoparticles clearly revealed the simultaneous presence of three phases: magnetite Fe3O4, maghemite γ-Fe2O3, and wustite FeO.

  19. Optimizing and modeling of effective parameters on the structural and magnetic properties of Fe{sub 3}O{sub 4} nanoparticles synthesized by coprecipitation technique using response surface methodology

    Energy Technology Data Exchange (ETDEWEB)

    Ghazanfari, Mohammad Reza [Department of Materials Science and Engineering, Ferdowsi University of Mashhad, 9177948974 Mashhad (Iran, Islamic Republic of); Kashefi, Mehrdad, E-mail: m-kashefi@um.ac.ir [Department of Materials Science and Engineering, Ferdowsi University of Mashhad, 9177948974 Mashhad (Iran, Islamic Republic of); Jaafari, Mahmoud Reza [Biotechnology Research Center, Nanotechnology Research Center, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad (Iran, Islamic Republic of)

    2016-07-01

    In present work, the Fe{sub 3}O{sub 4} magnetic nanoparticles were successfully synthesized by coprecipitation method. In order to study the effects of influential factors on the structural and magnetic properties of particles, the experimental runs were designed using response surface methodology (RSM) based on central composite design (CCD), while the reaction temperature, Fe{sup 2+}/Fe{sup 3+} cation ratio, and pH of reaction were defined as effective factors on the two responses include the amounts of crystallinity degree and saturation magnetization (M{sub s}). The investigation of structural, magnetic, and microstructural properties of particles were carried out by X-ray diffraction (XRD), vibrating sample magnetometer (VSM), and dynamic light scattering (DLS) and transmission electron microscopy (TEM) analyses. As a result, the predictive quadratic models were fitted on the both responses while the R{sup 2} values were more than 0.97 for both models. The highest amounts of both responses (crystallinity degree: 88.07% and M{sub s}: 65.801 emu/g) are presented when the reaction temperature, cation ratio, and pH amounts are equal to 90 °C, 0.60, and 10.5, respectively. Finally, the TEM results show the particles with size of about 10 nm and narrow size distribution. - Highlights: • The Fe{sub 3}O{sub 4} nanoparticles were successfully synthesized by coprecipitation method. • By RSM technique, the predictive models were presented for crystallinity degree. • By RSM technique, the predictive models were presented for amounts of M{sub s}. • Temperature, pH and their interactions had most effectiveness on the amounts of M{sub s}. • Temperature, cation ratio and their interactions had most effectiveness on the crystallinity degree.

  20. A facile approach to the elucidation of magnetic parameters of CuFe{sub 2}O{sub 4} nanoparticles synthesized by hydrothermal route

    Energy Technology Data Exchange (ETDEWEB)

    Kurian, Jessyamma [B.A.M. College, Thuruthicad, Mallappally, Kerala (India); Jacob Mathew, M., E-mail: jacob.chrisdale@gmail.com [S.B. College, Changanassery, Kerala (India)

    2017-04-15

    Pure pseudo cubic shaped copper ferrite nanoparticles with narrow size distribution in the range 6–17 nanometer are prepared by hydrothermal method under various synthesis conditions namely, hydrothermal temperature, heating time, and pH. The structural and morphological studies are carried out in detail using XRD and TEM analysis. The crystallite size and particle size are calculated from different characterization techniques. The distribution of cations among the tetrahedral and octahedral sites is determined from the XRD intensity calculation. Compositional features are determined from EDS analysis. Magnetic studies are carried out using VSM at room temperature and the important magnetic parameters are extracted from it. Contributions due to various types of magnetization to the total magnetization are determined from the theoretical fitting of the magnetization curve. Excellent fits are obtained for all samples prepared under various conditions. The ferromagnetic, superparamagnetic and paramagnetic contributions to the magnetization are determined from the analysis of fitted M-H curve. It is observed that the hydrothermal reaction time and temperature has little effect on the structural and magnetic parameters of the material. However, pH plays a crucial role in the physical properties of nanoparticles. Optimized synthesis conditions are identified for changing the soft ferrimagnetic nature of copper ferrite nanoparticles to superparamagnetic nature. - Highlights: • CuFe{sub 2}O{sub 4} particles of 6–17 nm size are produced by varying synthesis conditions. • Cubic single phase nano copper ferrite is obtained at a pH of 12. • Magnetic parameters calculated from theoretical fitting of M-H curves. • Dependence of the magnetic properties on Particle size and pH elucidated.

  1. Electron spin resonance in Cu{sub 1−x}Fe{sub x}Cr{sub 2}Se{sub 4} nanoparticles synthesized with the thermal decomposition method

    Energy Technology Data Exchange (ETDEWEB)

    Edelman, I.S., E-mail: ise@iph.krasn.ru [Kirensky Institute of Physics, Federal Research Center KSC, Russian Academy of Sciences, Krasnoyarsk 660036 (Russian Federation); Zharkov, S.M.; Pankrats, A.I. [Kirensky Institute of Physics, Federal Research Center KSC, Russian Academy of Sciences, Krasnoyarsk 660036 (Russian Federation); Siberian Federal University, Krasnoyarsk 660041 (Russian Federation); Vorotynov, A.M.; Tugarinov, V.I.; Ivantsov, R.D.; Petrov, D.A. [Kirensky Institute of Physics, Federal Research Center KSC, Russian Academy of Sciences, Krasnoyarsk 660036 (Russian Federation); Velikanov, D.A. [Kirensky Institute of Physics, Federal Research Center KSC, Russian Academy of Sciences, Krasnoyarsk 660036 (Russian Federation); Siberian Federal University, Krasnoyarsk 660041 (Russian Federation); Lin, Chun-Rong; Chen, Chin-Chang; Tseng, Yaw-Teng; Hsu, Hua-Shu [National Pingtung University, Pingtung City, Pingtung County 90003, Taiwan (China)

    2017-08-15

    Highlights: • Cu{sub 1−x}Fe{sub x}Cr{sub 2}Se{sub 4} nanoparticles were synthesized as (1 1 1) nanocrystalline plates. • Nanoparticles tend to form stacks consisting of plates attached “face to face”. • ESR parameters demonstrate unusual temperature dependences with a kink at 120–130 K. - Abstract: In this paper, we present a study of the electron spin resonance (ESR) of nanoparticles (NPs) of Cu{sub 1−x}Fe{sub x}Cr{sub 2}Se{sub 4} chalcogenides with x = 0, 0.2, and 0.4. NPs were synthesized via the thermal decomposition of metal chloride salts and selenium powder in a high-temperature organic solvent. According to the XRD and HRTEM data, the NPs were single crystalline nearly hexagonal plates with the structure close to CuCr{sub 2}Se{sub 4} (Fd-3m, a = 10.337 Å). For x = 0 and 0.2, the NPs tend to form long stacks consisting of the plates “face to face” attached to each other due to the magnetostatic interparticle interaction. Only separate NPs were observed in the case of x = 0.4. Peculiarities were revealed in the ESR temperature behavior for the NPs with x = 0 and 0.2 consistent with the features in the temperature dependences of the NPs magnetization. The non-monotonous dependence of the resonance field H{sub res} on the temperature with a kink near 130 K and the energy gap in the resonance spectrum depending on the type of nanoparticle compacting are the distinct peculiarities. One of the main factors is discussed in order to explain the peculiarities: the coexistence of two types of anisotropy in the Cu{sub 1−x}Fe{sub x}Cr{sub 2}Se{sub 4} NPs, in-plain shape anisotropy and magnetocrystalline anisotropy with four easy axes, which increases strongly with the temperature decrease.

  2. Effect of zinc oxide nanoparticles synthesized by a precipitation

    Indian Academy of Sciences (India)

    ZnO nanoparticles were synthesized by a precipitation method in aqueous media from zinc nitrate hexahydrate and sodium hydroxide. The synthesized ZnO nanoparticles exhibited a crystalline structure with hexagonal structure of the wurtzite. The morphology of the synthesized ZnO nanoparticles presented a spherical ...

  3. Characterization of hematite nanoparticles synthesized via two different pathways

    Science.gov (United States)

    Das, Soumya; Hendry, M. Jim

    2014-08-01

    Hematite is one of the most common and thermodynamically stable iron oxides found in both natural and anthropogenic systems. Owing to its ubiquity, stability, moderate specific surface area, and ability to sequester metals and metalloids from aquatic systems, it has been the subject of a large number of adsorption studies published during the past few decades. Although preparation techniques are known to affect the surface morphology of hematite nanoparticles, the effects of aging under environmentally relevant conditions have yet to be tested with respect to surface morphology, surface area, and adsorptive capacity. We prepared hematite via two different pathways and aged it under highly alkaline conditions encountered in many mill tailings settings. Crystal habits and morphologies of the hematite nanoparticles were analyzed via scanning electron microscopy and transmission electron microscopy. X-ray diffraction, Raman spectroscopy, and Brunauer-Emmett-Teller surface area analyses were also conducted on the hematite nanoparticles before and after aging. The hematite synthesized via an Fe(III) salt solution (average particle size 37 nm) was morphologically and structurally different from the hematite synthesized via ferrihydrite aging (average particle size 144 nm). Overall, our data demonstrate that the crystallinity of hematite produced via ferrihydrite transformation is susceptible to morphological alterations/modifications. In contrast, the hematite formed via hydrolysis of an Fe(III) salt solution remains very stable in terms of structure, size, and morphology even under extreme experimental conditions.

  4. Iron Nanoparticles (Fe3O4 Used to Synthesize Magnetic Sodium Alginate Hydrogel Beads for the Removal of Basic Blue 159 from Aqueous Solutions

    Directory of Open Access Journals (Sweden)

    Atiyeh Ghajarieh

    2017-11-01

    Full Text Available Dyes are a main source of pollutants in textile plant effluents. Due to their molecular structure, they are usually toxic, carcinogenous, and persistent in the environment. The aim of the present work was to explore the removal of basic blue159 (BB159 using magnetic sodium alginate hydrogel beads. Magnetic sodium alginate hydrogel beads were initially synthesized  accoriodng to Rocher method using CaCl2 as a crosslink agent. Fourier transform infrared spectroscopy (FTIR was then employed to examine the functional groups on the surface of the magnetic sodium alginate hydrogel beads. In a third stage, the magnetic properties of the beads were measured using a vibrating sample magnetometer (VSM and the magnetic parameters were calculated. Subsequently, the effects of such parameters as adsorbent dosage, pH, initial concentration of dye, and contact time were evaluated on the BB159 removal efficiency of the adsorbent used. Finally, the Langmuir, Freundlich, Temkin, and B.E.T models were exploited to study the adsorption isotherm of BB159 onto the magnetic sodium alginate hydrogel beads. It was found that the magnetic sodium alginate beads possess both –COO and –OH groups that play important roles in the adsorption of the positively charged BB159 dye. A saturation magnetization equal to 21/8(emu/g was obtained for the sodium alginate beads/nano Fe3O4. Results also revealed that the highest dye removal from aqueous solutions was achieved at pH=11 in 120 minutes for 9 grams of the adsorbent. The study indicated that BB159 removal using the magnetic sodium alginate hydrogel beads as the adsorbent obeys the Langmuir model. Moreover, it was shown that the efficiency of the process for BB159 removal from aqueous solutions was satisfactory (85%.

  5. Enzymes immobilization on Fe{sub 3}O{sub 4}-gold nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Kalska-Szostko, B., E-mail: kalska@uwb.edu.pl [Institute of Chemistry, University of Bialystok, Hurtowa 1, 15-399 Bialystok (Poland); Rogowska, M.; Dubis, A. [Institute of Chemistry, University of Bialystok, Hurtowa 1, 15-399 Bialystok (Poland); Szymanski, K. [Department of Physics, University of Bialystok, Lipowa 41, 15-424 Bialystok (Poland)

    2012-01-15

    In the present study Fe{sub 3}O{sub 4} magnetic nanoparticles were synthesized by coprecipitation of Fe{sup 2+} and Fe{sup 3+} from chlorides. In the next step magnetite-gold core-shell nanoparticles were synthesized from HAuCl{sub 4} using an ethanol as a reducing agent. Finally, magnetic nanoparticles were functionalized by hexadecanethiol. The immobilization of biological molecules (trypsin and glucose oxidase) to the thiol-modified and unmodified magnetite-gold nanoparticles surface was tested. The resulting nanoparticles were characterized by infrared spectroscopy, differential scanning calorimetry, Moessbauer spectroscopy and transmission electron microscopy.

  6. Green synthesized conditions impacting on the reactivity of Fe NPs for the degradation of malachite green.

    Science.gov (United States)

    Huang, Lanlan; Luo, Fang; Chen, Zuliang; Megharaj, Mallavarapu; Naidu, Ravendra

    2015-02-25

    This study investigates green tea extract synthesized conditions impacting on the reactivity of iron nanoparticles (Fe NPs) used for the degradation of malachite green (MG), including the volume ratio of Fe(2+) and tea extract, the solution pH and temperature. Results indicated that the reactivity of Fe NPs increased with higher temperature, but fell with increasing pH and the volume ratio of Fe(2+) and tea extract. Scanning electron microscope (SEM), energy-dispersive spectrometer (EDS), Fourier transform infrared spectroscope (FTIR) and X-ray diffraction (XRD) indicated that Fe NPs were spherical in shape, their diameter was 70-80 nm and they were mainly composed of iron oxide nanoparticles. UV-visible (UV-vis) indicated that reactivity of Fe NPs used in degradation of MG significantly depended on the synthesized conditions of Fe NPs. This was due to their impact on the reactivity and morphology of Fe NPs. Finally, degradation of MG showed that 90.56% of MG was removed using Fe NPs. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Radiolytic Syntheses of Nanoparticles and Inorganic-Polymer Hybrid Microgels

    International Nuclear Information System (INIS)

    Chen, Q.; Shi, J.; Zhao, R.; Shen, X.

    2010-01-01

    In the second year of the project, we have gotten progress mainly in two directions. Firstly, for the first time, Prussian blue (PB) nanoparticles (NPs) were successfully synthesized by the partly radiolytic reduction of Fe3+ and Fe(CN)63 in the presence of poly(N-vinyl pyrrolidine) (PVP) under N2 atmospheres at room temperature. With the increase of the concentration of PVP, the size and the size distribution of the synthesized quasi-spherical PB NPs decreased obviously, leading to a hypsochromic shift on their peak position of the characteristic absorption. In the experiment, we further found that the smaller ones have a larger capacity to Cs+, suggesting that the application of PB NPs in curing thallotoxicosis may decrease the usage of PB for the patient to great extent. Secondly, through a series of preliminary experiments, we got a clear picture about the one-step radiolytic preparation of inorganic-poly(methacrylic acid-co-methyl methacrylate) hybrid microgels by surfactant-free emulsion polymerization. Besides, unpurified N-carbamothioylmethacrylamide was synthesized via the methacrylation of thiourea. These created favorable conditions for the one-step synthesis of metal sulfide-poly(methacrylic acid-co-methyl methacrylate) hybrid microgels by -irradiation and surfactant-free emulsion polymerization. (author)

  8. Radiolytic Syntheses of Nanoparticles and Inorganic-Polymer Hybrid Microgels

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Q.; Shi, J.; Zhao, R.; Shen, X., E-mail: qdchen@pku.edu.cn [Department of Applied Chemistry, College of Chemistry and Molecular Engineering, Peking University, No. 5, Yiheyuan Load, Haidian District Beijing 100871 (China)

    2010-07-01

    In the second year of the project, we have gotten progress mainly in two directions. Firstly, for the first time, Prussian blue (PB) nanoparticles (NPs) were successfully synthesized by the partly radiolytic reduction of Fe3+ and Fe(CN)63 in the presence of poly(N-vinyl pyrrolidine) (PVP) under N2 atmospheres at room temperature. With the increase of the concentration of PVP, the size and the size distribution of the synthesized quasi-spherical PB NPs decreased obviously, leading to a hypsochromic shift on their peak position of the characteristic absorption. In the experiment, we further found that the smaller ones have a larger capacity to Cs+, suggesting that the application of PB NPs in curing thallotoxicosis may decrease the usage of PB for the patient to great extent. Secondly, through a series of preliminary experiments, we got a clear picture about the one-step radiolytic preparation of inorganic-poly(methacrylic acid-co-methyl methacrylate) hybrid microgels by surfactant-free emulsion polymerization. Besides, unpurified N-carbamothioylmethacrylamide was synthesized via the methacrylation of thiourea. These created favorable conditions for the one-step synthesis of metal sulfide-poly(methacrylic acid-co-methyl methacrylate) hybrid microgels by -irradiation and surfactant-free emulsion polymerization. (author)

  9. Size-controlled Synthesis and Characterization of Fe3O4 Nanoparticles by Chemical Coprecipitation Method

    International Nuclear Information System (INIS)

    Chia Chin Hua; Sarani Zakaria; Farahiyan, R.; Liew Tze Khong; Mustaffa Abdullah; Sahrim Ahmad; Nguyen, K.L.

    2008-01-01

    Magnetite (Fe 3 O 4 ) nanoparticles have been synthesized using the chemical coprecipitation method. The Fe 3 O 4 nanoparticles were likely formed via dissolution-recrystallization process. During the precipitation process, ferrihydrite and Fe(OH) 2 particles formed aggregates and followed by the formation of spherical Fe 3 O 4 particles. The synthesized Fe 3 O 4 nanoparticles exhibited superparamagnetic behavior and in single crystal form. The synthesis temperature and the degree of agitation during the precipitation were found to be decisive in controlling the crystallite and particle size of the produced Fe 3 O 4 nanoparticles. Lower temperature and higher degree of agitation were the favorable conditions for producing smaller particle. The magnetic properties (saturation magnetization and coercivity) of the Fe 3 O 4 nanoparticles increased with the particle size. (author)

  10. Identification of Spinel Iron Oxide Nanoparticles by 57Fe NMR

    Directory of Open Access Journals (Sweden)

    SangGap Lee

    2011-12-01

    Full Text Available We have synthesized and studied monodisperse iron oxide nanoparticles of smaller than 10 nm to identify between the two spinel phases, magnetite and maghemite. It is shown that 57Fe NMR spectroscopy is a promising tool for distinguishing between the two phases.

  11. Study on magnetite nanoparticles synthesized by chemical method

    International Nuclear Information System (INIS)

    Pei Wenli; Kumada, H.; Natusme, T.; Saito, H.; Ishio, S.

    2007-01-01

    Magnetite nanoparticles with controlled size were synthesized by chemical method. Higher deposition temperature and a rapid-raising temperature procedure are favorable to particle size distribution and fabrication of monodisperse nanoparticles. The larger nanoparticles can be synthesized by the two-step method. The large nanoparticle (up to 25 nm) without agglomeration was successfully produced. The saturation magnetization of 11 nm magnetite particles was 45 emu/g at room temperature, which is smaller than that of bulk magnetite due to surface effect. Hysteresis of the magnetite nanoparticle was very small, indicating superparamagnetic behavior. The magnetic domains of the 11 nm magnetite nanoparticles were successfully observed by MFM

  12. Mixed Contaminants Removal Efficiency Using Bio-FeS Nanoparticles.

    Science.gov (United States)

    Seo, Hyunhee; Roh, Yul

    2018-02-01

    Advances in nanotechnology has provided diverse industrial applications including an environmental remediation field. In particular, bio-nanotechnology gives extended eco-friendly remediation practice. Among diverse bio-nanoparticles synthesized by microorganisms, the iron based nanoparticles (NPs) are of great interest because of their availability, low cost and toxicity to human health and the environment. In this study, iron based nanoparticles were biologically synthesized and mineralogically identified. Also, the removal efficiency of mixed contaminants, high As(III)-low Cr(VI) and high As(V)-low Cr(VI), using these bio-nanoparticles were conducted. As a result, biologically synthesized NPs were identified as FeS complex and their catalytic capacity showed highly effective to immobilize more than 97% of mixed contaminants by adsorption/mineralization.

  13. Synthesis of Fe nanoparticles-graphene composites for environmental applications

    International Nuclear Information System (INIS)

    Guo, Juan; Wang, Ruiyu; Tjiu, Weng Weei; Pan, Jisheng; Liu, Tianxi

    2012-01-01

    Graphical abstract: Fe nanoparticles-graphene composites (FGC) are successfully synthesized by forming a complex Fe 3+ -GO and further reducing it with NaBH4 as one step at ambient condition. The morphology and structure studies of FGC indicate that Fe nanoparticles with size of about 5 nm are finely dispersed on graphene sheets. Decolorization experiments show that the FGC hybrids display better removal capacities to decolorize methyl blue (MB), a model dye in the dyeing and printing industry, compared with bare Fe particles. On the other hand, FGC hybrids exhibit superparamagnetic properties and can be separated from MB solution leaving a colorless solution by using a magnet. All of these suggest FGC an excellent candidate for dye removal. Highlights: ► Graphene oxide (GO) and Fe 3+ are used as precursors. ► By adding NaBH 4 , Fe 3+ and GO are in situ reduced to Fe and graphene, respectively, thus forming FGC hybrids. ► Fe nanoparticles with size of about 5 nm are finely dispersed on graphene sheets. ► FGC hybrids have better decolorization capacities than bare Fe nanoparticles. - Abstract: Fe nanoparticles-graphene composites (FGC) are successfully synthesized by using graphene oxide (GO) as a supporting matrix. GO is first treated with Fe 3+ to form Fe 3+ -GO complexes. Then, by adding NaBH 4 solution, Fe 3+ and GO are simultaneously reduced in situ to Fe and graphene respectively, forming FGC hybrid composites. The structures, properties and applications of the hybrids thus obtained are investigated by X-ray diffraction, Raman spectroscopy, Fourier transformed infrared spectroscopy, X-ray photoelectron spectroscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, thermogravimetric analysis and magnetization measurements. The hybrids are also evaluated for decolorization of methyl blue solution, a model dye in wastewater of dyeing industry. Compared with bare Fe particles, the high removal capacities of FGC are due to the

  14. Syntheses and characterizations of LiFePO4 powders

    OpenAIRE

    Jugović, Dragana; Kuzmanović, Maja; Mitrić, Miodrag; Cvjetićanin, Nikola; Uskoković, Dragan

    2011-01-01

    The olivine type compositions LiMPO4 (M = Fe, Mn, Co) are among the most attractive materials for the positive electrode of lithium-ion battery. The benefits of using LiFePO4 are excellent cycle life, high structural stability, low cost and environmental friendliness. Here will be presented our efforts to obtain LiFePO4 powders through several synthesis methods. The differences in phase purity, microstructure, morphology, and electrochemical performances of synthesized powders were investigat...

  15. Exchange-coupled Fe3O4/CoFe2O4 nanoparticles for advanced magnetic hyperthermia

    Science.gov (United States)

    Glassell, M.; Robles, J.; Das, R.; Phan, M. H.; Srikanth, H.

    Iron oxide nanoparticles especially Fe3O4, γ-Fe2O3 have been extensively studied for magnetic hyperthermia because of their tunable magnetic properties and stable suspension in superparamagnetic regime. However, their relatively low heating capacity hindered practical application. Recently, a large improvement in heating efficiency has been reported in exchange-coupled nanoparticles with exchange coupling between soft and hard magnetic phases. Here, we systematically studied the effect of core and shell size on the heating efficiency of the Fe3O4/CoFe2O4 core/shell nanoparticles. The nanoparticles were synthesized using thermal decomposition of organometallic precursors. Transmission electron microscopy (TEM) showed formation of spherical shaped Fe3O4 and Fe3O-/CoFe2O4 nanoparticles. Magnetic measurements showed high magnetization (≅70 emu/g) and superparamagnetic behavior for the nanoparticles at room temperature. Magnetic hyperthermia results showed a large increase in specific absorption rate (SAR) for 8nm Fe3O4/CoFe2O4 compared to Fe3O4 nanoparticles of the same size. The heating efficiency of the Fe3O4/CoFe2O4 with 1 nm CoFe2O4 (shell) increased from 207 to 220 W/g (for 800 Oe) with increase in core size from 6 to 8 nm. The heating efficiency of the Fe3O4/CoFe2O4 with 2 nm CoFe2O4 (shell) and core size of 8 nm increased from 220 to 460 W/g (for 800 Oe). These exchange-coupled Fe3O4/CoFe2O4 core/shell nanoparticles can be a good candidate for advanced hyperthermia application.

  16. Aloe vera plant-extracted solution hydrothermal synthesis and magnetic properties of magnetite (Fe3O4) nanoparticles

    Science.gov (United States)

    Phumying, Santi; Labuayai, Sarawuth; Thomas, Chunpen; Amornkitbamrung, Vittaya; Swatsitang, Ekaphan; Maensiri, Santi

    2013-06-01

    Magnetite (Fe3O4) nanoparticles have been successfully synthesized by a novel hydrothermal method using ferric acetylacetonate (Fe(C5H8O2)3) and aloe vera plant-extracted solution. The influences of different reaction temperatures and times on the structure and magnetic properties of the synthesized Fe3O4 nanoparticles were investigated. The synthesized nanoparticles are crystalline and have particle sizes of ˜6-30 nm, as revealed by transmission electron microscopy (TEM). The results of X-ray diffraction (XRD), High resolution TEM (HRTEM) and selected area electron diffraction (SAED) indicate that the synthesized Fe3O4 nanoparticles have the inverse cubic spinel structure without the presence of any other phase impurities. The hysteresis loops of the Fe3O4 nanoparticles at room temperature show superparamagnetic behavior and the saturation magnetization of the Fe3O4 samples increases with increasing reaction temperature and time.

  17. Biocarbon-coated LiFePO4 nucleus nanoparticles enhancing electrochemical performances

    DEFF Research Database (Denmark)

    Zhang, X.G.; Zhang, X.D.; He, W.

    2012-01-01

    We report a green biomimetic method to synthesize biocarbon-coated LiFePO4 nucleus nanoparticles using yeast cells as both a structural template and a biocarbon source for high-power lithium-ion batteries.......We report a green biomimetic method to synthesize biocarbon-coated LiFePO4 nucleus nanoparticles using yeast cells as both a structural template and a biocarbon source for high-power lithium-ion batteries....

  18. Electrochemical sensing behaviour of Ni doped Fe{sub 3}O{sub 4} nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Suresh, R.; Giribabu, K.; Manigandan, R.; Narayanan, V., E-mail: vnnara@yahoo.co.in [Department of Inorganic Chemistry, University of Madras, Guindy Campus, Chennai 600 025 (India); Vijayalakshmi, L. [Annai Veilankanni' s College for Women (Arts and Science), Saidapet, Chennai 600015 (India); Stephen, A. [Department of Nuclear Physics, University of Madras, Guindy Campus, Chennai 600 025 (India)

    2014-01-28

    Ni doped Fe{sub 3}O{sub 4} nanoparticles were synthesized by simple hydrothermal method. The prepared nanomaterials were characterized by X-ray diffraction analysis, DRS-UV-Visible spectroscopy and field emission scanning electron microscopy. The XRD confirms the phase purity of the synthesized Ni doped Fe{sub 3}O{sub 4} nanoparticles. The optical property of Ni doped Fe{sub 3}O{sub 4} nanoparticles were studied by DRS UV-Visible analysis. The electrochemical sensing property of pure and Ni doped Fe{sub 3}O{sub 4} nanoparticles were examined using uric acid as an analyte. The obtained results indicated that the Ni doped Fe{sub 3}O{sub 4} nanoparticles exhibited higher electrocatalytic activity towards uric acid.

  19. Biomedical applications of green synthesized Nobel metal nanoparticles.

    Science.gov (United States)

    Khan, Zia Ul Haq; Khan, Amjad; Chen, Yongmei; Shah, Noor S; Muhammad, Nawshad; Khan, Arif Ullah; Tahir, Kamran; Khan, Faheem Ullah; Murtaza, Behzad; Hassan, Sadaf Ul; Qaisrani, Saeed Ahmad; Wan, Pingyu

    2017-08-01

    Synthesis of Nobel metal nanoparticles, play a key role in the field of medicine. Plants contain a substantial number of organic constituents, like phenolic compounds and various types of glycosides that help in synthesis of metal nanoparticles. Synthesis of metal nanoparticles by green method is one of the best and environment friendly methods. The major significance of the green synthesis is lack of toxic by-products produced during metal nanoparticle synthesis. The nanoparticles, synthesized by green method show various significant biological activities. Most of the research articles report the synthesized nanoparticles to be active against gram positive and gram negative bacteria. Some of these bacteria include Escherichia coli, Bacillus subtilis, Klebsiella pneumonia and Pseudomonas fluorescens. The synthesized nanoparticles also show significant antifungal activity against Trichophyton simii, Trichophyton mentagrophytes and Trichophyton rubrum as well as different types of cancer cells such as breast cancer cell line. They also exhibit significant antioxidant activity. The activities of these Nobel metal nano-particles mainly depend on the size and shape. The particles of small size with large surface area show good activity in the field of medicine. The synthesized nanoparticles are also active against leishmanial diseases. This research article explores in detail the green synthesis of the nanoparticles and their uses thereof. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. LiFePO4 nanoparticles encapsulated in graphene nanoshells for high-performance lithium-ion battery cathodes.

    Science.gov (United States)

    Fei, Huilong; Peng, Zhiwei; Yang, Yang; Li, Lei; Raji, Abdul-Rahman O; Samuel, Errol L G; Tour, James M

    2014-07-11

    LiFePO4 encapsulated in graphene nanoshells (LiFePO4@GNS) nanoparticles were synthesized by solid state reaction between graphene-coated Fe nanoparticles and LiH2PO4. The resulting nanocomposite was demonstrated to be a superior lithium-ion battery cathode with improved cycle and rate performances.

  1. Synthesis of FeCoNi nanoparticles by galvanostatic technique

    International Nuclear Information System (INIS)

    Budi, Setia; Hafizah, Masayu Elita; Manaf, Azwar

    2016-01-01

    Soft magnetic nanoparticles of FeCoNi have been becoming interesting objects for many researchers due to its potential application in electronic devices. One of the most promising methods for material preparation is the electrodeposition which capable of growing nanoparticles alloy directly onto the substrate. In this paper, we report our electrodeposition studies on nanoparticles synthesis using galvanostatic electrodeposition technique. Chemical composition of the synthesized FeCoNi was successfully controlled through the adjustment of the applied currents. It is revealed that the content of each element, obtained from quantitative analysis using atomic absorption spectrometer (AAS), could be modified by the adjustment of current in which Fe and Co content decreased at larger applied currents, while Ni content increased. The nanoparticles of Co-rich FeCoNi and Ni-rich FeCoNi were obtained from sulphate electrolyte at the range of applied current investigated in this work. Broad diffracted peaks in the X-ray diffractograms indicated typical nanostructures of the solid solution of FeCoNi.

  2. Synthesis of FeCoNi nanoparticles by galvanostatic technique

    Energy Technology Data Exchange (ETDEWEB)

    Budi, Setia, E-mail: setiabudi@unj.ac.id [Potgraduate Program of Materials Science Study, Department of Physics, Faculty of Mathematics and Natural Sciences, Universitas Indonesia, Depok 16424 (Indonesia); Department of Chemistry, Faculty of Mathematics and Sciences, Universitas Negeri Jakarta, Jl. Pemuda No.10, Rawamangun, Jakarta 13220 (Indonesia); Hafizah, Masayu Elita; Manaf, Azwar, E-mail: azwar@ui.ac.id [Potgraduate Program of Materials Science Study, Department of Physics, Faculty of Mathematics and Natural Sciences, Universitas Indonesia, Depok 16424 (Indonesia)

    2016-06-17

    Soft magnetic nanoparticles of FeCoNi have been becoming interesting objects for many researchers due to its potential application in electronic devices. One of the most promising methods for material preparation is the electrodeposition which capable of growing nanoparticles alloy directly onto the substrate. In this paper, we report our electrodeposition studies on nanoparticles synthesis using galvanostatic electrodeposition technique. Chemical composition of the synthesized FeCoNi was successfully controlled through the adjustment of the applied currents. It is revealed that the content of each element, obtained from quantitative analysis using atomic absorption spectrometer (AAS), could be modified by the adjustment of current in which Fe and Co content decreased at larger applied currents, while Ni content increased. The nanoparticles of Co-rich FeCoNi and Ni-rich FeCoNi were obtained from sulphate electrolyte at the range of applied current investigated in this work. Broad diffracted peaks in the X-ray diffractograms indicated typical nanostructures of the solid solution of FeCoNi.

  3. Antibacterial properties of silver nanoparticles synthesized by marine Ochrobactrum sp.

    Science.gov (United States)

    Thomas, Roshmi; Janardhanan, Anju; Varghese, Rintu T; Soniya, E V; Mathew, Jyothis; Radhakrishnan, E K

    2014-01-01

    Metal nanoparticle synthesis is an interesting area in nanotechnology due to their remarkable optical, magnetic, electrical, catalytic and biomedical properties, but there needs to develop clean, non-toxic and environmental friendly methods for the synthesis and assembly of nanoparticles. Biological agents in the form of microbes have emerged up as efficient candidates for nanoparticle synthesis due to their extreme versatility to synthesize diverse nanoparticles with varying size and shape. In the present study, an eco favorable method for the biosynthesis of silver nanoparticles using marine bacterial isolate has been attempted. Very interestingly, molecular identification proved it as a strain of Ochrobactrum anhtropi. In addition, the isolate was found to have the potential to form silver nanoparticles intracellularly at room temperature within 24 h. The biosynthesized silver nanoparticles were characterized by UV-Vis spectroscopy, transmission electron microscope (TEM) and scanning electron microscope (SEM). The UV-visible spectrum of the aqueous medium containing silver nanoparticles showed a peak at 450 nm corresponding to the plasmon absorbance of silver nanoparticles. The SEM and TEM micrographs revealed that the synthesized silver nanoparticles were spherical in shape with a size range from 38 nm - 85 nm. The silver nanoparticles synthesized by the isolate were also used to explore its antibacterial potential against pathogens like Salmonella Typhi, Salmonella Paratyphi, Vibrio cholerae and Staphylococcus aureus.

  4. Antibacterial properties of silver nanoparticles synthesized by marine Ochrobactrum sp.

    Directory of Open Access Journals (Sweden)

    Roshmi Thomas

    2014-12-01

    Full Text Available Metal nanoparticle synthesis is an interesting area in nanotechnology due to their remarkable optical, magnetic, electrical, catalytic and biomedical properties, but there needs to develop clean, non-toxic and environmental friendly methods for the synthesis and assembly of nanoparticles. Biological agents in the form of microbes have emerged up as efficient candidates for nanoparticle synthesis due to their extreme versatility to synthesize diverse nanoparticles with varying size and shape. In the present study, an eco favorable method for the biosynthesis of silver nanoparticles using marine bacterial isolate has been attempted. Very interestingly, molecular identification proved it as a strain of Ochrobactrum anhtropi. In addition, the isolate was found to have the potential to form silver nanoparticles intracellularly at room temperature within 24 h. The biosynthesized silver nanoparticles were characterized by UV-Vis spectroscopy, transmission electron microscope (TEM and scanning electron microscope (SEM. The UV-visible spectrum of the aqueous medium containing silver nanoparticles showed a peak at 450 nm corresponding to the plasmon absorbance of silver nanoparticles. The SEM and TEM micrographs revealed that the synthesized silver nanoparticles were spherical in shape with a size range from 38 nm - 85 nm. The silver nanoparticles synthesized by the isolate were also used to explore its antibacterial potential against pathogens like Salmonella Typhi, Salmonella Paratyphi, Vibrio cholerae and Staphylococcus aureus.

  5. Observation of high coercive fields in chemically synthesized coated Fe-Pt nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Dalavi, Shankar B.; Panda, Rabi N., E-mail: rnp@goa.bits-pilani.ac.in

    2017-04-15

    Nanocrystalline Fe-Pt alloys have been synthesized via chemical reduction route using various capping agents; such as: oleic acid/oleylamine (route-1) and oleic acid/CTAB (route-2). We could able to synthesize Fe50Pt and Fe54Pt alloys via route 1 and 2, respectively. As-prepared Fe-Pt alloys crystallize in disordered fcc phase with crystallite sizes of 2.3 nm and 6 nm for route-1 and route-2, respectively. Disordered Fe-Pt alloys were transformed to ordered fct phase after annealing at 600 °C. SEM studies confirm the spherical shape morphologies of annealed Fe-Pt nanoparticles with SEM particle sizes of 24.4 nm and 21.2 nm for route-1 and route-2, respectively. TEM study confirms the presence of 4.6 nm particles for annealed Fe50Pt alloys with several agglomerating clusters of bigger size and appropriately agrees well with the XRD study. Room temperature magnetization studies of as-prepared Fe-Pt alloys (fcc) show ferromagnetism with negligible coercivities. Average magnetic moments per particle for as-prepared Fe-Pt alloys were estimated to be 753 μ{sub B} and 814 μ{sub B}, for route 1 and 2, respectively. Ordered fct Fe-Pt alloys show high values of coercivities of 10,000 Oe and 10,792 Oe for route-1 and route-2, respectively. Observed magnetic properties of the fct Fe-Pt alloys nps were interpreted with the basis of order parameters, size, surface, and composition effects. - Highlights: • Synthesis of capped nanocrystalline Fe-Pt alloys via chemical routes. • Ordered fct phase were obtained at 600 °C. • Microstructural studies were carried out using SEM and TEM. • Investigation on evolution of magnetic properties from fcc to fct state. • Maximum values of coercivities up to 10,792 Oe were observed.

  6. Ni doped Fe3O4 magnetic nanoparticles.

    Science.gov (United States)

    Larumbe, S; Gómez-Polo, C; Pérez-Landazábal, J I; García-Prieto, A; Alonso, J; Fdez-Gubieda, M L; Cordero, D; Gómez, J

    2012-03-01

    In this work, the effect of nickel doping on the structural and magnetic properties of Fe3O4 nanoparticles is analysed. Ni(x)Fe(3-x)O4 nanoparticles (x = 0, 0.04, 0.06 and 0.11) were obtained by chemical co-precipitation method, starting from a mixture of FeCl2 x 4H2O and Ni(AcO)2 x 4H2O salts. The analysis of the structure and composition of the synthesized nanoparticles confirms their nanometer size (main sizes around 10 nm) and the inclusion of the Ni atoms in the characteristic spinel structure of the magnetite Fe3O4 phase. In order to characterize in detail the structure of the samples, X-ray absorption (XANES) measurements were performed on the Ni and Fe K-edges. The results indicate the oxidation of the Ni atoms to the 2+ state and the location of the Ni2+ cations in the Fe2+ octahedral sites. With respect to the magnetic properties, the samples display the characteristic superparamagnetic behaviour, with anhysteretic magnetic response at room temperature. The estimated magnetic moment confirms the partial substitution of the Fe2+ cations by Ni2+ atoms in the octahedral sites of the spinel structure.

  7. Antibacterial activity of magnetic iron oxide nanoparticles synthesized by laser ablation in liquid

    International Nuclear Information System (INIS)

    Ismail, Raid A.; Sulaiman, Ghassan M.; Abdulrahman, Safa A.; Marzoog, Thorria R.

    2015-01-01

    In this study, (50–110 nm) magnetic iron oxide (α-Fe 2 O 3 ) nanoparticles were synthesized by pulsed laser ablation of iron target in dimethylformamide (DMF) and sodium dodecyl sulfate (SDS) solutions. The structural properties of the synthesized nanoparticles were investigated by using Fourier Transform Infrared (FT-IR) spectroscopy, UV–VIS absorption, scanning electron microscopy (SEM), atomic force microscopy (AFM), and X-ray diffraction (XRD). The effect of laser fluence on the characteristics of these nanoparticles was studied. Antibacterial activities of iron oxide nanoparticles were tested against Gram-positive; Staphylococcus aureus and Gram-negative; Escherichia coli, Pseudomonas aeruginosa and Serratia marcescens. The results showed a noteworthy inhibition on both bacterial strains. The preparation conditions were found to affect significantly the antibacterial activity of these nanoparticles. The synthesized magnetic nanoparticles were used to capture rapidly S. aureus bacteria under the magnetic field effect. - Highlights: • Synthesis magnetic iron oxide nanoparticles by pulsed laser ablation • Antibacterial activity against Gram-positive and Gram-negative bacteria • Captured magnetic nanoparticles by S. aureus bacteria under effect of magnetic field

  8. Antibacterial activity of magnetic iron oxide nanoparticles synthesized by laser ablation in liquid

    Energy Technology Data Exchange (ETDEWEB)

    Ismail, Raid A., E-mail: raidismail@yahoo.com [Laser Physics Division, Applied Science Department, University of Technology, Baghdad (Iraq); Sulaiman, Ghassan M. [Biotechnology Division, Applied Science Department, University of Technology, Baghdad (Iraq); Abdulrahman, Safa A. [Laser Physics Division, Applied Science Department, University of Technology, Baghdad (Iraq); Marzoog, Thorria R. [Biotechnology Division, Applied Science Department, University of Technology, Baghdad (Iraq)

    2015-08-01

    In this study, (50–110 nm) magnetic iron oxide (α-Fe{sub 2}O{sub 3}) nanoparticles were synthesized by pulsed laser ablation of iron target in dimethylformamide (DMF) and sodium dodecyl sulfate (SDS) solutions. The structural properties of the synthesized nanoparticles were investigated by using Fourier Transform Infrared (FT-IR) spectroscopy, UV–VIS absorption, scanning electron microscopy (SEM), atomic force microscopy (AFM), and X-ray diffraction (XRD). The effect of laser fluence on the characteristics of these nanoparticles was studied. Antibacterial activities of iron oxide nanoparticles were tested against Gram-positive; Staphylococcus aureus and Gram-negative; Escherichia coli, Pseudomonas aeruginosa and Serratia marcescens. The results showed a noteworthy inhibition on both bacterial strains. The preparation conditions were found to affect significantly the antibacterial activity of these nanoparticles. The synthesized magnetic nanoparticles were used to capture rapidly S. aureus bacteria under the magnetic field effect. - Highlights: • Synthesis magnetic iron oxide nanoparticles by pulsed laser ablation • Antibacterial activity against Gram-positive and Gram-negative bacteria • Captured magnetic nanoparticles by S. aureus bacteria under effect of magnetic field.

  9. Effect of precursor supply on structural and morphological characteristics of fe nanomaterials synthesized via chemical vapor condensation method.

    Science.gov (United States)

    Ha, Jong-Keun; Ahn, Hyo-Jun; Kim, Ki-Won; Nam, Tae-Hyun; Cho, Kwon-Koo

    2012-01-01

    Various physical, chemical and mechanical methods, such as inert gas condensation, chemical vapor condensation, sol-gel, pulsed wire evaporation, evaporation technique, and mechanical alloying, have been used to synthesize nanoparticles. Among them, chemical vapor condensation (CVC) has the benefit of its applicability to almost all materials because a wide range of precursors are available for large-scale production with a non-agglomerated state. In this work, Fe nanoparticles and nanowires were synthesized by chemical vapor condensation method using iron pentacarbonyl (Fe(CO)5) as the precursor. The effect of processing parameters on the microstructure, size and morphology of Fe nanoparticles and nanowires were studied. In particular, we investigated close correlation of size and morphology of Fe nanoparticles and nanowires with atomic quantity of inflow precursor into the electric furnace as the quantitative analysis. The atomic quantity was calculated by Boyle's ideal gas law. The Fe nanoparticles and nanowires with various diameter and morphology have successfully been synthesized by the chemical vapor condensation method.

  10. Study the Polyol Process of Preparing the ru Doped FePt Nanoparticles

    Science.gov (United States)

    Lee, Chih-Hao; Hsu, Jen-Ho; Su, Hui-Chia; Huang, Tzu Wen

    The structure of Ru doped FePt nanoparticles using polyol process was studied. The particle size grown is around 5 nm, and a shell structure might be formed. By selecting the time and temperature of adding the Ru precursors into solution, three different processes to synthesize the FePtRu particles were studied resulting in different growing mechanics. The possible models during the reaction process are also discussed. The phase transition temperature for the as-grown FCC FePt nanoparticle to transform into L10 FePt nanoparticle is about 823 K which is about the same as the one without doping Ru atoms. From the XAS study of each element, the possible scenario is that: although Ru atoms with the size close to the Pt, they do not totally replace the Pt sites in the FePt alloy. Instead, most of Ru formed a shell outside the FePt nanoparticles and Fe atoms are replaced.

  11. XRD analysis of undoped and Fe doped TiO2 nanoparticles by Williamson Hall method

    International Nuclear Information System (INIS)

    Bharti, Bandna; Barman, P. B.; Kumar, Rajesh

    2015-01-01

    Undoped and Fe doped titanium dioxide (TiO 2 ) nanoparticles were synthesized by sol-gel method at room temperature. The synthesized samples were annealed at 500°C. For structural analysis, the prepared samples were characterized by X-ray diffraction (XRD). The crystallite size of TiO 2 and Fe doped TiO 2 nanoparticles were calculated by Scherer’s formula, and was found to be 15 nm and 11 nm, respectively. Reduction in crystallite size of TiO 2 with Fe doping was observed. The anatase phase of Fe-doped TiO 2 nanoparticles was also confirmed by X-ray diffraction. By using Williamson-Hall method, lattice strain and crystallite size were also calculated. Williamson–Hall plot indicates the presence of compressive strain for TiO 2 and tensile strain for Fe-TiO 2 nanoparticles annealed at 500°C

  12. Biological activities of synthesized silver nanoparticles from ...

    Indian Academy of Sciences (India)

    during the processing or storage of food and in that way help. ∗. Author for ... scale which have been applied in the field of drug delivery, catalysis, optical devices ..... nanoparticles will undergo electrostatic interaction with negatively charged ...

  13. Biosynthesis of silver nanoparticles synthesized by Aspergillus ...

    Indian Academy of Sciences (India)

    Biotechnology Division, Applied Science Department, University of ... Abstract. In the present study, biosynthesis of silver nanoparticles and its antioxidant, antimicrobial and cytotoxic ... example of the biosynthesis using fungi was that the cell-.

  14. Synthesizing nanoparticles by mimicking nature | Science ...

    Science.gov (United States)

    As particulate matter with at least one dimension that is less than 100 nm, nanoparticles are the minuscule building blocks of new commercial products and consumer materials in the emerging field of nanotechnology. Nanoparticles are being discovered and introduced in the marketplace at a very fast pace. Also, commercial interest in nanotechnology has significantly increased, translating into more than a multibillion-dollar investment from public and private sources. Among several unique properties, nanoparticles have an exceptionally large surface area–to-volume ratio, which is the most important of the characteristics that are responsible for their widespread use in an array of industries. Unfortunately, their small size and corresponding high surface area often create a number of problems. For instance, the outer layer of atoms may have a different composition, and therefore a different chemistry, from the rest of the particle. Furthermore, nanoparticle surfaces are sensitive to changes in redox conditions, pH, ionic strength, and the types of microorganisms present. The synthesis of metal nanoparticles has been the subject of intense research, primarily because of their unique properties and their potential applications from a technological point of view. The optical, magnetic, electronic, and catalytic properties of these materials depend on their morphology and size distribution. Noble-metal nanoparticles are of particular interest because of their close-

  15. Synthesis of superparamagnetic δ-FeOOH nanoparticles by a chemical method

    Energy Technology Data Exchange (ETDEWEB)

    Nishida, Naoki, E-mail: nnishida@rs.tus.ac.jp [Department of Chemistry, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo 162-8601 (Japan); Amagasa, Shota [Department of Chemistry, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo 162-8601 (Japan); Kobayashi, Yoshio [Department of Engineering Science, The University of Electro-Communications, 1-5-1 Chofugaoka, Chofu, Tokyo 182-8585 (Japan); Nishina Center for Accelerator-Based Science, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Yamada, Yasuhiro [Department of Chemistry, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo 162-8601 (Japan)

    2016-11-30

    Highlights: • The spherical δ-FeOOH nanoparticles were synthesized by a chemical reaction of FeCl{sub 2}. • The δ-FeOOH nanoparticles showed superparamagnetic behavior. • A mixture of Fe{sub 3}O{sub 4} and Fe(OH){sub 2} were rapidly oxidized into δ-FeOOH nanoparticles. - Abstract: δ-FeOOH nanoparticles were synthesized via the oxidation of precipitates obtained from the reaction of FeCl{sub 2} and N{sub 2}H{sub 4} in the presence of sodium tartrate and gelatin in an alkaline condition. These δ-FeOOH particles were subsequently examined using transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), powder X-ray diffraction (XRD), Mössbauer spectroscopy, and superconducting quantum interference device (SQUID) assessment. The average size of the δ-FeOOH nanoparticles was below 10 nm, and these particles exhibited superparamagnetic behavior as a result of this small size. The precursors of the δ-FeOOH nanoparticles were also characterized as a means of elucidating the reaction mechanism. Precipitates prior to oxidation upon rinsing with water and ethanol were analyzed by obtaining XRD patterns and Mössbauer spectra of wet and frozen samples, respectively. The precipitates obtained by the reaction of FeCl{sub 2} and N{sub 2}H{sub 4} were found to consist of a mixture of Fe{sub 3}O{sub 4} and Fe(OH){sub 2}, and it is believed that these species then rapidly oxidized into δ-FeOOH nanoparticles.

  16. Conjugating folate on superparamagnetic Fe3O4@Au nanoparticles using click chemistry

    International Nuclear Information System (INIS)

    Shen, Xiaofang; Ge, Zhaoqiang; Pang, Yuehong

    2015-01-01

    Gold-coated magnetic core@shell nanoparticles, which exhibit magneto-optical properties, not only enhance the chemical stability of core and biocompatibility of surface, but also provide a combination of multimodal imaging and therapeutics. The conjugation of these tiny nanoparticles with specific biomolecules allows researchers to target the desired location. In this paper, superparamagnetic Fe 3 O 4 @Au nanoparticles were synthesized and functionalized with the azide group on the surface by formation of self-assembled monolayers. Folate (FA) molecules, non-immunogenic target ligands for cancer cells, are conjugated with alkyne and then immobilized on the azide-terminated Fe 3 O 4 @Au nanoparticles through copper(I)-catalyzed azide-alkyne cycloaddition (click reaction). Myelogenous leukemia K562 cells were used as a folate receptor (FR) model, which can be targeted and extracted by magnetic field after interaction with the Fe 3 O 4 @Au–FA nanoparticles. - Graphical abstract: Self-assembled azide-terminated group on superparamagnetic Fe 3 O 4 @Au nanoparticles followed by click reaction with alkyne-functionalized folate, allowing the nanoparticles target folate receptor of cancer cells. - Highlights: • Azidoundecanethiol was coated on the superparamagnetic Fe 3 O 4 @Au nanoparticles by forming self-assembled monolayers. • Alkyne-terminated folate was synthesized from a reaction between the amine and the carboxylic acid. • Conjugation of Fe 3 O 4 @Au nanoparticles with folate was made by copper-catalyzed azide-alkyne cycloaddition click chemistry

  17. Effect of Ni doping on the structural and magnetic properties of FePt nanoparticles

    International Nuclear Information System (INIS)

    Yang, H.-W.; Chung, C.-M.; Ding, Jack Y.

    2007-01-01

    A serial of FePtNi nanoparticles were investigated on their crystal structure and magnetic properties. The FePtNi nanoparticles were synthesized simultaneously by the reduction of iron (III) acetylacetonate, platinum (II) acetylacetonate and nickel (II) acetylacetonate with 1,2-hexadecanediol as the reducing agent. The X-ray diffraction patterns indicate that the addition of 8, 12, 17 at% Ni in FePt nanoparticles suppressed the transformation of the particles from disorder face-centered cubic to order face-centered tetragonal L1 0 -phase under annealing treatment. However, further increasing Ni contents to 21 at%, the nanoparticle transformed to L1 2 phase. Doping of Ni into the FePt compound system may decrease coercivity and crystal anisotropy energy. A maximum coercivity of 7 KOe at room temperature was obtained for (Fe 52 Pt 48 ) 92 Ni 8 nanoparticles after annealing at 600 deg. C for 30 min

  18. Catalysts synthesized by selective deposition of Fe onto Pt for the water-gas shift reaction

    Energy Technology Data Exchange (ETDEWEB)

    Aragao, Isaias Barbosa; Ro, Insoo; Liu, Yifei; Ball, Madelyn; Huber, George W.; Zanchet, Daniela; Dumesic, James A.

    2018-03-01

    FePt bimetallic catalysts with intimate contact between the two metals were synthesized by controlled surface reactions (CSR) of (cyclohexadiene)iron tricarbonyl with hydrogen-treated supported Pt nanoparticles. Adsorption of the iron precursor on a Pt/SiO2 catalyst was studied, showing that the Fe loading could be increased by performing multiple CSR cycles, and the efficiency of this process was linked to the renewal of adsorption sites by a reducing pretreatment. The catalytic activity of these bimetallic catalysts for the water gas shift reaction was improved due to promotion by iron, likely linked to H2O activation on FeOx species at or near the Pt surface, mostly in the (II) oxidation state.

  19. Biocarbon-coated LiFePO4 nucleus nanoparticles enhancing electrochemical performances.

    Science.gov (United States)

    Zhang, Xueguang; Zhang, Xudong; He, Wen; Yue, Yuanzheng; Liu, Hong; Ma, Jingyun

    2012-10-18

    We report a simple, inexpensive green biomimetic way for developing the high performance LiFePO(4) for high-power lithium-ion batteries. Biocarbon-coated LiFePO(4) nucleus nanoparticles are synthesized by using yeast cells as both a structural template and a biocarbon source.

  20. Synthesis and properties MFe2O4 (M = Fe, Co) nanoparticles and core-shell structures

    Science.gov (United States)

    Yelenich, O. V.; Solopan, S. O.; Greneche, J. M.; Belous, A. G.

    2015-08-01

    Individual Fe3-xO4 and CoFe2O4 nanoparticles, as well as Fe3-xO4/CoFe2O4 core/shell structures were synthesized by the method of co-precipitation from diethylene glycol solutions. Core/shell structure were synthesized with CoFe2O4-shell thickness of 1.0, 2.5 and 3.5 nm. X-ray diffraction patterns of individual nanoparticles and core/shell are similar and indicate that all synthesized samples have a cubic spinel structure. Compares Mössbauer studies of CoFe2O4, Fe3-xO4 nanoparticles indicate superparamagnetic properties at 300 K. It was shown that individual magnetite nanoparticles are transformed into maghemite through oxidation during the synthesis procedure, wherein the smallest nanoparticles are completely oxidized while a magnetite core does occur in the case of the largest nanoparticles. The Mössbauer spectra of core/shell nanoparticles with increasing CoFe2O4-shell thickness show a gradual decrease in the relative intensity of the quadrupole doublet and significant decrease of the mean isomer shift value at both RT and 77 K indicating a decrease of the superparamagnetic relaxation phenomena. Specific loss power for the prepared ferrofluids was experimentally calculated and it was determined that under influence of ac-magnetic field magnetic fluid based on individual CoFe2O4 and Fe3-xO4 particles are characterized by very low heating temperature, when magnetic fluids based on core/shell nanoparticles demonstrate higher heating effect.

  1. Biological activities of synthesized silver nanoparticles

    Indian Academy of Sciences (India)

    The C. halicacabum leaf extract synthesized AgNPs efficiency were tested against different bacterial pathogens MTCC-426 Proteus vulgaris, MTCC-2453 Pseudomonas aeruginosa, MTCC-96 Staphylococcus aureus, MTCC-441 Bacillus subtilis andMTCC-735 Salmonella paratyphi, and fungal pathogens Alternaria solani ...

  2. Synthesis of γ–Fe2O3 nanoparticles with crystallographic and ...

    African Journals Online (AJOL)

    user

    Maghemite (γ-Fe2O3) nanoparticles are synthesized by chemical ... In most of the reported methods, initially the particles have been synthesized in a non polar ... Carbon coated copper grid and was used for TEM characterization using an FEI ..... Currently he is Professor of Physics at IIT Kanpur working in the areas of ...

  3. Fine tuning of size and morphology of magnetite nanoparticles synthesized by microemulsion

    Science.gov (United States)

    Singh, Pinki; Upadhyay, Chandan

    2018-05-01

    The synthesis parameters crucially affect the physical and chemical parameters of nanoparticles. Magnetite (Fe3O4) nanoparticles were synthesized using microemulsion method. This method does not require high temperature synthesis, nitrogen environment and/or pH regulation during synthesis process. We are presenting here a systematic study on role of different associated parameters of microemulsion synthesis method on the formation of Fe3O4 nanoparticles. From X-ray Diffraction and Transmission Electron Micoscopy data analysis the size of synthesized particles were observed to be <10 nm. The critical concentration of ferrous-ferric solution to obtain particles in single phase has been found to be ≤0.09 M and ≤0.184 M, respectively. The variation of molar concentration (0.01 M ≤x≤ 0.1 M) of CTAB leads to formation of Fe3O4 nano-scale particles of distinct morphologies e.g. nano-cubes, pentagons and spheres. The number of ferrous and ferric ions involved in the formation decides the size of the nanoparticles. The single crystallographic phase is obtained in reaction temperature range of 65° C

  4. Monodisperse Silver Nanoparticles Synthesized by a Microwave-Assisted Method

    International Nuclear Information System (INIS)

    Shao-Peng, Zhu; Shao-Chun, Tang; Xiang-Kang, Meng

    2009-01-01

    Silver nanoparticles with an average size of about 20 nm are synthesized in a colloidal solution with the aid of microwave irradiation. Neither additional reductant nor stabilizer is required in this microwave-assisted method. The color of the colloidal solution is found to be dark green, different from the characteristic yellow of silver colloidal solutions. The silver nanoparticles in the colloidal solution have a narrow size distribution and large yield quantity. UV-visible absorption spectroscopy analysis reveals that the as-synthesized monodisperse silver nanoparticles have exceptional optical properties. Raman spectroscopy measurements demonstrate that these silver nanoparticles exhibit a notable surface-enhanced Raman scattering ability. (cross-disciplinary physics and related areas of science and technology)

  5. Structural investigations on differently sized monodisperse iron oxide nanoparticles synthesized by remineralization of apoferritin molecules

    International Nuclear Information System (INIS)

    Ullrich, Aladin; Horn, Siegfried

    2013-01-01

    We have investigated the structure of iron oxide nanoparticles produced by remineralization and thermal treatment of horse spleen apoferritin molecules. The described procedure allows to synthesize particles with diameters ranging from 4 to 7 nm in size. Atomic force microscopy and transmission electron microscopy (TEM) investigations were performed for shape and size determination, whereas energy-dispersive X-ray (TEM-EDX), high-resolution TEM, and electron diffraction measurements revealed the chemical composition and crystal structure of the particles. We found predominantly single crystalline nanoparticles with a hematite-like (α-Fe 2 O 3 ) structure

  6. Chemical phase analysis of seed mediated synthesized anisotropic silver nanoparticles

    International Nuclear Information System (INIS)

    Bharti, Amardeep; Goyal, Navdeep; Singh, Suman; Singla, M. L.

    2015-01-01

    Noble-metal nanoparticles are of great interest because of its broad applications almost in every stream (i.e. biology, chemistry and engineering) due to their unique size/shape dependant properties. In this paper, chemical phase of seed mediated synthesized anisotropic silver nanoparticle (AgNPs) has been investigated via fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). These nanaoparticles were synthesized by seed-growth method controlled by urea and dextrose results to highly stable 12-20 nm particle size revealed by zeta potential and transmission electron microscopy (TEM)

  7. Analysis of Ag nanoparticles synthesized by bioreduction.

    Science.gov (United States)

    Tavera-Davila, L; Liu, H B; Herrera-Becerra, R; Canizal, G; Balcazar, M; Ascencio, J A

    2009-03-01

    Based on a green chemistry mechanism, small silver clusters were obtained by using biosynthesis with alfalfa (medicago sativa), controlling the size of the nanoparticles base don different pH conditions. The analysis of the samples was made with help of transmission electron microscopy methods, mainly with high angle annular dark field and high resolution transmission electron microscopy. The optimal conditions were identified when the sample was obtained at pH10, which allowed obtaining an average size of 4.09 nm and a standard deviation of 1.59, mainly based on cubic like structures.

  8. A facile route to synthesize nanogels doped with silver nanoparticles

    Science.gov (United States)

    Coll Ferrer, M. Carme; Ferrier, Robert C.; Eckmann, David M.; Composto, Russell J.

    2013-01-01

    In this study, we describe a simple method to prepare hybrid nanogels consisting of a biocompatible core-shell polymer host containing silver nanoparticles. First, the nanogels (NG, 160 nm) containing a lysozyme rich core and a dextran rich shell, are prepared via Maillard and heat-gelation reactions. Second, silver nanoparticles (Ag NPs, 5 nm) are synthesized "in situ" in the NG solution without requiring additional reducing agents. This approach leads to stable Ag NPs located in the NG. Furthermore, we demonstrate that the amount of Ag NPs in the NG can be tuned by varying silver precursor concentration. Hybrid nanogels with silver nanoparticles have potential in antimicrobial, optical, and therapeutic applications.

  9. Use of Fe3O4 Nanoparticles for Enhancement of Biosensor Response to the Herbicide 2,4-Dichlorophenoxyacetic Acid

    OpenAIRE

    Loh, Kee-Shyuan; Lee, Yook Heng; Musa, Ahmad; Salmah, Abdul Aziz; Zamri, Ishak

    2008-01-01

    Magnetic nanoparticles of Fe3O4 were synthesized and characterized using transmission electron microscopy and X-ray diffraction. The Fe3O4 nanoparticles were found to have an average diameter of 5.48 ±1.37 nm. An electrochemical biosensor based on immobilized alkaline phosphatase (ALP) and Fe3O4 nanoparticles was studied. The amperometric biosensor was based on the reaction of ALP with the substrate ascorbic acid 2-phosphate (AA2P). The incorporation of the Fe3O4 nanoparticles together wit...

  10. Leishmanicidal Activity of Biogenic Fe3O4 Nanoparticles

    Directory of Open Access Journals (Sweden)

    Mehrdad Khatami

    2017-11-01

    Full Text Available Abstract: Due to the multiplicity of useful applications of metal oxide nanoparticles (ONPs in medicine are growing exponentially, in this study, Fe3O4 (iron oxide nanoparticles (IONPs were biosynthesized using Rosemary to evaluate the leishmanicidal efficiency of green synthesized IONPs. This is the first report of the leishmanicidal efficiency of green synthesized IONPs against Leishmania major. The resulting biosynthesized IONPs were characterized by ultraviolet-visible spectroscopy (UV-Vis, X-ray diffraction (XRD, transmission electron microscopy (TEM, and Fourier transform infrared spectroscopy (FTIR. The leishmanicidal activity of IONPS was studied via 3-4,5-dimethylthiazol-2-yl-2,5-diphenyltetrazolium bromide (MTT assay. The results showed the fabrication of the spherical shape of monodisperse IONPs with a size 4 ± 2 nm. The UV-visible spectrophotometer absorption peak was at 334 nm. The leishmanicidal activity of biogenic iron oxide nanoparticles against Leishmania major (promastigote was also studied. The IC50 of IONPs was 350 µg/mL. In this report, IONPs were synthesized via a green method. IONPs are mainly spherical and homogeneous, with an average size of about 4 nm, and were synthesized here using an eco-friendly, simple, and inexpensive method.

  11. Optical and Luminescence Properties of β-NaFeO2 Nanoparticles

    Science.gov (United States)

    Singh, Sarbjit; Tangra, Ankush Kumar; Lotey, Gurmeet Singh

    2018-05-01

    β-NaFeO2 nanoparticles have been synthesized by sol-gel method and their morphological, structural and optical properties investigated. Transmission electron microscope study reveals that the size of the synthesis nanoparticles is 37 nm and they are possessing spherical symmetry. X-ray diffraction pattern shows the orthorhombic crystal structure of nanoparticles with space group Pn21 a. UV-visible spectra of β-NaFeO2 divulges that these nanoparticles have direct band gap 2.35 eV. The observed Fourier transform infrared spectroscopy spectra confirms the presence of Fe-Na bonding at 1074 cm-1. The photoluminescence study of these nanoparticles shows that these nanoparticles possesses various transition in the visible spectrum.

  12. Antibacterial potential of silver nanoparticle synthesized by marine ...

    African Journals Online (AJOL)

    Multi resistance to antibiotics is a serious and disseminated clinical problem, common to several new compounds that block the resistance mechanism. The present study aimed at the comparative study of silver nanoparticles synthesized through actinomycetes and their antimicrobial metabolites with standard antibiotic.

  13. ARSENIC REMOVAL USING SOL-GEL SYNTHESIZED TITANIUM DIOXIDE NANOPARTICLES

    Science.gov (United States)

    In this study, the effectiveness of TiO2 nanoparticles in arsenic adsorption was examined. TiO2 particles (LS) were synthesized via sol-gel techniques and characterized for their crystallinity, surface area and pore volume. Batch adsorption studies were perf...

  14. Characterization of chemically synthesized CdS nanoparticles

    Indian Academy of Sciences (India)

    Similar to the effects of charge carriers on optical properties, confinement of optical and acoustic phonons leads to interesting changes in the phonon spectra. In the present work, we have synthesized nanoparticles of CdS using chemical precipitation technique. The crystal structure and grain size of the particles are studied ...

  15. Reduced graphene oxide decorated with Fe doped SnO{sub 2} nanoparticles for humidity sensor

    Energy Technology Data Exchange (ETDEWEB)

    Toloman, D. [National Institute for Research and Development of Isotopic and Molecular Technologies, 67-103 Donat Street, 400293 Cluj-Napoca (Romania); Popa, A., E-mail: popa@itim-cj.ro [National Institute for Research and Development of Isotopic and Molecular Technologies, 67-103 Donat Street, 400293 Cluj-Napoca (Romania); Stan, M.; Socaci, C.; Biris, A.R. [National Institute for Research and Development of Isotopic and Molecular Technologies, 67-103 Donat Street, 400293 Cluj-Napoca (Romania); Katona, G. [Babes-Bolyai University, Faculty of Chemistry and Chemical Engineering, 11 Arany Janos Street, 400028 Cluj-Napoca (Romania); Tudorache, F. [Interdisciplinary Research Department – Field Science & RAMTECH, Al. I. Cuza University, 11 Carol I Blvd., 7000506 Iasi (Romania); Petrila, I. [Interdisciplinary Research Department – Field Science & RAMTECH, Al. I. Cuza University, 11 Carol I Blvd., 7000506 Iasi (Romania); Faculty of Automatic Control and Computer Engineering, Gheorghe Asachi Technical University, 27 Dimitrie Mangeron Street, 700050 Iasi (Romania); Iacomi, F. [Faculty of Physics, Al. I. Cuza University, 11 Carol I Blvd., 7000506 Iasi (Romania)

    2017-04-30

    Highlights: • Reduced graphene oxide decorated with Fe doped SnO{sub 2} nanoparticles were synthesized. • The decoration of rGO layers with SnO{sub 2}:Fe nanoparticles was highlited by TEM. • The reduction of graphene oxide was evidenced using XRD and FT-IR. • Sensitivity tests for relative humidity (RH) were carried out. • The composite sensor exhibited enhanced sensing response as compared with Fe:SnO{sub 2}. - Abstract: Reduced graphene oxide (rGO) decorated with Fe doped SnO{sub 2} nanoparticles were fabricated via the electrostatic interaction between positively charged modified Fe-doped SnO{sub 2} oxide and negatively charged graphene oxide (GO) in the presence of poly(allylamine) hydrochloride (PAH). The decoration of rGO layers with SnO{sub 2}:Fe nanoparticles was highlited by TEM microsopy. For composite sample the diffraction patterns coincide well with those of SnO{sub 2}:Fe nanoparticles. The reduction of graphene oxide was evidenced using XRD and FT-IR spectroscopy. The formation of SnO{sub 2}:Fe-PAH-graphene composites was confirmed by FT-IR, Raman and EPR spectroscopy. Sensitivity tests for relative humidity (RH) measurements were carried out at five different concentrations of humid air at room temperature. The prepared composite sensor exhibited a higher sensing response as compared with Fe:SnO{sub 2} nanoparticles.

  16. Size-Controlled Synthesis of Fe3O4 Magnetic Nanoparticles in the Layers of Montmorillonite

    Directory of Open Access Journals (Sweden)

    Katayoon Kalantari

    2014-01-01

    Full Text Available Iron oxide nanoparticles (Fe3O4-NPs were synthesized using chemical coprecipitation method. Fe3O4-NPs are located in interlamellar space and external surfaces of montmorillonite (MMT as a solid supported at room temperature. The size of magnetite nanoparticles could be controlled by varying the amount of NaOH as reducing agent in the medium. The interlamellar space changed from 1.24 nm to 2.85 nm and average diameter of Fe3O4 nanoparticles was from 12.88 nm to 8.24 nm. The synthesized nanoparticles were characterized using some instruments such as transmission electron microscopy, powder X-ray diffraction, energy dispersive X-ray spectroscopy, field emission scanning electron microscopy, vibrating sample magnetometer, and Fourier transform infrared spectroscopy.

  17. Structural characterization of FeVO{sub 4} synthesized by co-precipitation method

    Energy Technology Data Exchange (ETDEWEB)

    Bera, Ganesh; Sinha, Sourav; Rambabu, P.; Das, P.; Gupta, A. K.; Turpu, G. R., E-mail: dr.tgreddy@gmail.com [Department of Pure and Applied Physics, Guru Ghasidas Vishwavidyalaya, Koni, Bilaspur 495 009 (India)

    2016-05-06

    A Low temperature method for synthesizing triclinic FeVO{sub 4} nanoparticles is manifested through co-precipitation method. Three precursor materials taken for the synthesis are Iron Nitrate, Ammonium Metavanadate and NaOH along with DI water. The attained precipitate was dried at 100°C for overnight and calcined at different temperatures ranging from 400°C - 650°C. The achieved powdered materials are studied through X-ray diffraction and found to be in pure single phase of P-1 space group symmetry. The crystallite size measured through Scherrer’s method is in found to be in the range of 40-60 nm. Raman spectroscopic studies were carried out at room temperature. Raman spectra is in agreement with the reported structural data of FeVO{sub 4}.

  18. Toxicity of PEG-Coated CoFe2O4 Nanoparticles with Treatment Effect of Curcumin

    Science.gov (United States)

    Akhtar, Shahnaz; An, Wenzhen; Niu, Xiaoying; Li, Kang; Anwar, Shahzad; Maaz, Khan; Maqbool, Muhammad; Gao, Lan

    2018-02-01

    In this work, CoFe2O4 nanoparticles coated with polyethylene glycol (PEG) were successfully synthesized via a hydrothermal technique. Morphological studies of the samples confirmed the formation of polycrystalline pure-phase PEG-CoFe2O4 nanoparticles with sizes of about 24 nm. Toxicity induced by CoFe2O4 nanoparticles was investigated, and biological assays were performed to check the toxicity effects of CoFe2O4 nanoparticles. Moreover, the healing effect of toxicity induced in living organisms was studied using curcumin and it was found that biochemical indexes detoxified and improved to reach its normal level after curcumin administration. Thus, PEG-coated CoFe2O4 synthesized through a hydrothermal method can be utilized in biomedical applications and curcumin, which is a natural chemical with no side effects, can be used for the treatment of toxicity induced by the nanoparticles in living organisms.

  19. Cytotoxicity and antimicrobial activities of green synthesized silver nanoparticles.

    Science.gov (United States)

    Lokina, S; Stephen, A; Kaviyarasan, V; Arulvasu, C; Narayanan, V

    2014-04-09

    Bio-inspired silver nanoparticles are synthesized using Malus domestica (apple) extract. Polyphenols present in the apple extract act as a reducing and capping agent to produce the silver nanoparticles. UV-Visible analysis shows the surface plasmon resonance (SPR) absorption at 420 nm. The FTIR analysis was used to identify the functional groups responsible for the bio-reduction of silver ion. The XRD and HRTEM images confirm the formation of silver nanoparticles. The minimal inhibitory concentration (MIC) of silver nanoparticles was recorded against most of the bacteria and fungus. Further, MCF-7 human breast adenocarcinoma cancer cell line was employed to observe the efficacy of cancer cell killing. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  20. Rapid decolorization of textile wastewater by green synthesized iron nanoparticles.

    Science.gov (United States)

    Ozkan, Z Y; Cakirgoz, M; Kaymak, E S; Erdim, E

    2018-01-01

    The effectiveness of green tea (Camellia sinensis) and pomegranate (Punica granatum) extracts for the production of iron nanoparticles and their application for color removal from a textile industry wastewater was investigated. Polyphenols in extracts act as reducing agents for iron ions in aqueous solutions, forming iron nanoparticles. Pomegranate extract was found to have almost a 10-fold higher polyphenolic content than the same amount of green tea extract on a mass basis. However, the size of the synthesized nanoparticles did not show a correlation with the polyphenolic content. 100 ppm and 300 ppm of iron nanoparticles were evaluated in terms of color removal efficiency from a real textile wastewater sample. 300 ppm of pomegranate nanoscale zero-valent iron particles showed more than 95% color removal and almost 80% dissolved organic carbon removal. The degradation mechanisms are is considered to be adsorption and precipitation to a major extent, and mineralization to a minor extent.

  1. Hyaluronic acid-modified hydrothermally synthesized iron oxide nanoparticles for targeted tumor MR imaging.

    Science.gov (United States)

    Li, Jingchao; He, Yao; Sun, Wenjie; Luo, Yu; Cai, Hongdong; Pan, Yunqi; Shen, Mingwu; Xia, Jindong; Shi, Xiangyang

    2014-04-01

    We report a polyethyleneimine (PEI)-mediated approach to synthesizing hyaluronic acid (HA)-targeted magnetic iron oxide nanoparticles (Fe3O4 NPs) for in vivo targeted tumor magnetic resonance (MR) imaging applications. In this work, Fe3O4 NPs stabilized by PEI were first synthesized via a one-pot hydrothermal method. The formed PEI-stabilized Fe3O4 NPs were then modified with fluorescein isothiocyanate (FI) and HA with two different molecular weights to obtain two different Fe3O4 NPs (Fe3O4-PEI-FI-HA6K and Fe3O4-PEI-FI-HA31K NPs) with a size of 15-16 nm. The formed HA-modified multifunctional Fe3O4 NPs were characterized via different techniques. We show that the multifunctional Fe3O4 NPs are water-dispersible and colloidal stable in different aqueous media. In vitro cell viability and hemolysis studies reveal that the particles are quite cytocompatible and hemocompatible in the given concentration range. Furthermore, confocal microscopy and flow cytometry data demonstrate that HA-targeted Fe3O4 NPs are able to be uptaken specifically by cancer cells overexpressing CD44 receptors, and be used as efficient probes for targeted MR imaging of cancer cells in vitro and xenografted tumor models in vivo. With the tunable amine-based conjugation chemistry, the PEI-stabilized Fe3O4 NPs may be functionalized with other biological ligands or drugs for diagnosis and therapy of different biological systems. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Evaluation of cytotoxicity of polypyrrole nanoparticles synthesized by oxidative polymerization

    Energy Technology Data Exchange (ETDEWEB)

    Vaitkuviene, Aida [Department of Physical Chemistry, Faculty of Chemistry, Vilnius University, Naugarduko 24, LT-03225 Vilnius (Lithuania); Department of Stem Cell Biology, State Research Institute Center for Innovative Medicine, Zygimantu 9, LT-01102 Vilnius (Lithuania); Kaseta, Vytautas [Department of Stem Cell Biology, State Research Institute Center for Innovative Medicine, Zygimantu 9, LT-01102 Vilnius (Lithuania); Voronovic, Jaroslav [Department of Physical Chemistry, Faculty of Chemistry, Vilnius University, Naugarduko 24, LT-03225 Vilnius (Lithuania); Ramanauskaite, Giedre; Biziuleviciene, Gene [Department of Stem Cell Biology, State Research Institute Center for Innovative Medicine, Zygimantu 9, LT-01102 Vilnius (Lithuania); Ramanaviciene, Almira [NanoTechnas–Center of Nanotechnology and Material Science at Department of Analytical and Environmental Chemistry, Faculty of Chemistry, Vilnius University, Naugarduko 24, 03225 Vilnius (Lithuania); Ramanavicius, Arunas, E-mail: Arunas.Ramanavicius@chf.vu.lt [Department of Physical Chemistry, Faculty of Chemistry, Vilnius University, Naugarduko 24, LT-03225 Vilnius (Lithuania); Laboratory of BioNanoTechnology, Department of Materials Science and Electronics, Institute of Semiconductor Physics, State Scientific Research Institute Centre for Physical Sciences and Technology, A. Gostauto 11, LT-01108 Vilnius (Lithuania)

    2013-04-15

    Highlights: ► Polypyrrole nanoparticles synthesized by environmentally friendly polymerization at high concentrations are cytotoxic. ► Primary mouse embryonic fibroblast, mouse hepatoma and human T lymphocyte Jurkat cell lines were treated by Ppy nanoparticles. ► Polypyrrole nanoparticles at high concentrations inhibit cell proliferation. -- Abstract: Polypyrrole (Ppy) is known as biocompatible material, which is used in some diverse biomedical applications and seeming to be a very promising for advanced biotechnological applications. In order to increase our understanding about biocompatibility of Ppy, in this study pure Ppy nanoparticles (Ppy-NPs) of fixed size and morphology were prepared by one-step oxidative polymerization and their cyto-compatibility was evaluated. The impact of different concentration of Ppy nanoparticles on primary mouse embryonic fibroblasts (MEF), mouse hepatoma cell line (MH-22A), and human T lymphocyte Jurkat cell line was investigated. Cell morphology, viability/proliferation after the treatment by Ppy nanoparticles was evaluated. Obtained results showed that Ppy nanoparticles at low concentrations are biocompatible, while at high concentrations they became cytotoxic for Jurkat, MEF and MH-22A cells, and it was found that cytotoxic effect is dose-dependent.

  3. Magnet-induced temporary superhydrophobic coatings from one-pot synthesized hydrophobic magnetic nanoparticles.

    Science.gov (United States)

    Fang, Jian; Wang, Hongxia; Xue, Yuhua; Wang, Xungai; Lin, Tong

    2010-05-01

    In this paper, we report on the production of superhydrophobic coatings on various substrates (e.g., glass slide, silicon wafer, aluminum foil, plastic film, nanofiber mat, textile fabrics) using hydrophobic magnetic nanoparticles and a magnet-assembly technique. Fe(3)O(4) magnetic nanoparticles functionalized with a thin layer of fluoroalkyl silica on the surface were synthesized by one-step coprecipitation of Fe(2+)/Fe(3+) under an alkaline condition in the presence of a fluorinated alkyl silane. Under a magnetic field, the magnetic nanoparticles can be easily deposited on any solid substrate to form a thin superhydrophobic coating with water contact angle as high as 172 degrees , and the surface superhydrophobicity showed very little dependence on the substrate type. The particulate coating showed reasonable durability because of strong aggregation effect of nanoparticles, but the coating layer can be removed (e.g., by ultrasonication) to restore the original surface feature of the substrates. By comparison, the thin particle layer deposited under no magnetic field showed much lower hydrophobicity. The main reason for magnet-induced superhydrophobic surfaces is the formation of nano- and microstructured surface features. Such a magnet-induced temporary superhydrophobic coating may have wide applications in electronic, biomedical, and defense-related areas.

  4. Antibacterial activity of silver nanoparticles synthesized from serine

    Energy Technology Data Exchange (ETDEWEB)

    Jayaprakash, N. [Catalysis and Nanomaterials Research Laboratory, Department of Chemistry, Loyola College, Chennai 600 034 (India); SRM Valliammai Engineering College, Department of Chemistry, Chennai 603 203 (India); Judith Vijaya, J., E-mail: jjvijayaloyola@yahoo.co.in [Catalysis and Nanomaterials Research Laboratory, Department of Chemistry, Loyola College, Chennai 600 034 (India); John Kennedy, L. [Materials Division, School of Advanced Sciences, VIT University, Chennai Campus, Chennai 600 048 (India); Priadharsini, K.; Palani, P. [Department of Center for Advanced Study in Botany, University of Madras, Guindy Campus, Chennai 600 025 (India)

    2015-04-01

    Silver nanoparticles (Ag NPs) were synthesized by a simple microwave irradiation method using polyvinyl pyrrolidone (PVP) as a capping agent and serine as a reducing agent. UV–Visible spectra were used to confirm the formation of Ag NPs by observing the surface plasmon resonance (SPR) band at 443 nm. The emission spectrum of Ag NPs showed an emission band at 484 nm. In the presence of microwave radiation, serine acts as a reducing agent, which was confirmed by Fourier transformed infrared (FT-IR) spectrum. High-resolution transmission electron microscopy (HR-TEM) and high-resolution scanning electron microscopy (HR-SEM) were used to investigate the morphology of the synthesized sample. These images showed the sphere-like morphology. The elemental composition of the sample was determined by the energy dispersive X-ray analysis (EDX). Selected area electron diffraction (SAED) was used to find the crystalline nature of the Ag NPs. The electrochemical behavior of the synthesized Ag NPs was analyzed by the cyclic voltammetry (CV). Antibacterial experiments showed that the prepared Ag NPs showed relatively similar antibacterial activities, when compared with AgNO{sub 3} against Gram-positive and Gram-negative bacteria. - Highlights: • Microwave irradiation method is used to synthesize silver nanoparticles. • Highly stable silver nanoparticles are produced from serine. • A detailed study of antibacterial activities is discussed. • Formation mechanism of silver microspheres has been proposed.

  5. Evaluation of Biological Activities of Chemically Synthesized Silver Nanoparticles

    International Nuclear Information System (INIS)

    Mostafa, A. A.; Solkamy, E.N.; Sayed, Sh. R. M.; Khan, M.; Shaik, M.R.; Al-Warthan, A.; Adil, S.F.

    2015-01-01

    Silver nanoparticles were synthesized by the earlier reported methods. The synthesized nanoparticles were characterized using ultraviolet-visible spectrophotometry (UV/Vis), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), and X-ray powder diffraction (XRD). The synthesized materials were also evaluated for their antibacterial activity against Gram positive and Gram negative bacterial strains. TEM micrograph showed the spherical morphology of AgNPs with size range of 40-60 nm. The synthesized nanoparticles showed a strong antimicrobial activity and their effect depends upon bacterial strain as AgNPs exhibited greater inhibition zone for Pseudomonas aeruginosa (19.1 mm) followed by Staphylococcus aureus (14.8?mm) and S. pyogenes (13.6 mm) while the least activity was observed for Salmonella typhi (12.5 mm) at concentration of 5 μg/disc. The minimum inhibitory concentration (MIC) of AgNPs against S. aureus was 2.5 μg/disc and less than 2.5 μg/disc for P. aeruginosa. These results suggested that AgNPs can be used as an effective antiseptic agent for infectious control in medical field.

  6. Comparative studies on structural properties and antimicrobial potential of spinel ferrite nanoparticles synthesized using various methods

    Science.gov (United States)

    Baraliya, Jagdish D.; Rakhashiya, Purvi M.; Patel, Pooja P.; Thaker, Vrinda S.; Joshi, Hiren H.

    2017-05-01

    In this study, novel multifunctional magnetic iron-based nanoparticles (CoFe2O4) coated with silica, silica-DEG (diethylene glycol), PEG (polyethylene glycol) were synthesized using Auto Combustion Method (ACM), Co-precipitation Method (COPM), Citrate Precursor Method (CPM), Flash Combustion Method (FCM). These spinel ferrite nanoparticles also contain very high antibacterial properties to fulfill the requirements of a drug delivery system so that the antibiotic concentration could be minimized. A potential delivery system could be based on a ferromagnetic fluid. The effects of various preparation methods on the physical properties of the nanoparticles were examined. The nanoparticles were also tested against four human pathogenic bacteria (Gram negative E.coli, P. aeruginosa, Gram positive S. aureus, S. pyogenus) and two fungi (C. albicans, A.niger). It was revealed that a nanoparticle has strong antibacterial activity as compared to antifungal. Further, Gram positive bacteria are more affected than Gram negative bacteria. It was also clear that different methods of coating have great influence on the antimicrobial properties. It was observed that these nanoparticles have significantly different but potentially very high antimicrobial activities against the tested organisms than found elsewhere by other nanoparticles on the same organisms.

  7. Copper nanoparticles synthesized in polymers by ion implantation

    DEFF Research Database (Denmark)

    Popok, Vladimir; Nuzhdin, Vladimir; Valeev, Valerij

    2015-01-01

    nanoparticles are observed to partly tower above the sample surface due to a side effect of high-fluence irradiation leading to considerable sputtering of polymers. Implantation and particle formation significantly change optical properties of both polymers reducing transmittance in the UV-visible range due...... as optical transmission spectroscopy. It is found that copper nanoparticles nucleation and growth are strongly fluence dependent as well as they are affected by the polymer properties, in particular, by radiation stability yielding different nanostructures for the implanted PI and PMMA. Shallow synthesized...

  8. Fe3O4 nanoparticles decorated MWCNTs @ C ferrite nanocomposites and their enhanced microwave absorption properties

    Science.gov (United States)

    Zhang, Kaichuang; Gao, Xinbao; Zhang, Qian; Chen, Hao; Chen, Xuefang

    2018-04-01

    Fe3O4 nanoparticles decorated MWCNTs @ C ferrite nanocomposites were synthesized using a co-precipitation method and a calcination process. As one kind absorbing material, we researched the electromagnetic absorption properties of the composites that were mixed with a filler loading of 80 wt% paraffin. In addition, we studied the influence of the magnetic nanoparticle content on the absorbing properties. The results showed that the frequency corresponding to the maximum absorptions shifted to lower frequency when the magnetic nanoparticles content increased. The Fe3O4 nanoparticles decorated MWCNTs @ C ferrite nanocomposites with approximately 60% Fe3O4 nanoparticles showed the best electromagnetic absorption properties. The maximum reflection loss was -52.47 dB with a thickness of 2.0 mm at 10.4 GHz.

  9. Magnetic and photocatalytic studies on Zn1-xMgxFe2O4 nanocolloids synthesized by solvothermal reflux method.

    Science.gov (United States)

    Manohar, A; Krishnamoorthi, C

    2017-12-01

    Biocompatible magnetic semiconductor Zn 1-x Mg x Fe 2 O 4 (x=0, 0.1, 0.3, 0.5 & 0.7) nanoparticles of around 10nm diameter were synthesized by solvothermal reflux method. The method produces well separated and narrow size distributed nanoparticles. Crystal structure, morphology, particles surface properties, surfactant quantity, colloidal stability, magnetic properties and photocatalytic properties of the synthesized nanoparticles were studied. Different characterizations confirmed that all compounds were single crystals and superparamagnetic at room temperature. Saturation mass magnetization (M s =57.5emu/g) enhances with substituent Mg 2+ concentration due to promotion of mixed spinel (normal and inverse) structure. Photocatalytic activity of all synthesized magnetic semiconductor nanoparticles were studied through methylene blue degradation. The degradation of 98% methylene blue was observed on 60 min irradiation of light. It is observed that photocatalytic activity slightly enhances with substituent Mg 2+ concentration. The synthesized biocompatible magnetic semiconductor nanoparticles can be utilized as photocatalysts and could also be recycled and separated by applying an external magnetic field. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Thermal plasma synthesis of Fe1−xNix alloy nanoparticles

    International Nuclear Information System (INIS)

    Raut, Suyog A.; Kanhe, Nilesh S.; Bhoraskar, S. V.; Mathe, V. L.; Das, A. K.

    2014-01-01

    Fe-Ni alloy nanoparticles are of great interest because of diverse practical applications in the fields such as magnetic fluids, high density recording media, catalysis and medicine. We report the synthesis of Fe-Ni nanoparticles via thermal plasma route. Thermal plasma assisted synthesis is a high temperature process and gives high yields of production. Here, we have used direct arc thermal plasma plume of 6kw as a source of energy at operating pressure 500 Torr. The mixture of Fe-Ni powder in required proportion (Fe 1−x Ni x ; x=0.30, 0.32, 0.34, 0.36, 0.38 and 0.40) was made to evaporate simultaneously from the graphite anode in thermal plasma reactor to form Fe-Ni bimetallic nanoparticles. The as synthesized particles were characterized by X-Ray Diffraction (XRD), Thermo-Gravimetric Analysis/Differential Scanning Calorimtry (TGA/DSC)

  11. Synthesis and characterization of chemically ordered FePt magnetic nano-particles

    Energy Technology Data Exchange (ETDEWEB)

    Srinivasa Rao, K. [Centre for Materials for Electronics Technology (C-MET), IDA phase-III, Cherlapally, Hyderabad 500 051 (India); Balaji, T., E-mail: theerthambalaji@yahoo.co [Centre for Materials for Electronics Technology (C-MET), IDA phase-III, Cherlapally, Hyderabad 500 051 (India); Lingappa, Y. [Department of Chemistry, Sri Venkateswara University, Tirupati 517 502 (India); Reddy, M.R.P.; Kumar, Arbind; Prakash, T.L. [Centre for Materials for Electronics Technology (C-MET), IDA phase-III, Cherlapally, Hyderabad 500 051 (India)

    2010-08-15

    Monodispersed FePt alloy magnetic nano-particles are prepared by reduction of platinum acetyl acetonate and iron acetyl acetonate salts together in the presence of oleic acid and oleyl amine stabilizers by polyol process. The particle size of FePt is in the range of 2-3 nm confirmed by transmission electron microscopy (TEM). As-synthesized FePt nano-particles are chemically disordered with face centre cubic (fcc) structure where as after vacuum annealing these particles changed to face centre tetragonal (fct) ordered structure confirmed by the X-ray diffraction technique. Magnetic coercivity of 5.247 KOe was observed for fct structure.

  12. Syntheses of crosslinked latex nanoparticles using differential microemulsion polymerization

    Science.gov (United States)

    Hassmoro, N. F.; Rusop, M.; Abdullah, S.

    2013-06-01

    The differential microemulsion polymerization was used to synthesize latex nanoparticles. In this paper, 1, 3-butylene glycol dimethacrylate (1, 3-BGDMA) was used as a crosslinker respectively 1-5 weight% of monomer total. Butyl acrylate (BA), butyl methacrylate (BMA), and methacrylic acid (MAA) was used as the monomer. The thin film of latex nanoparticles were prepared by using spin coating method and have been dried at 100°C for 5 minutes. The amount of the crosslinker added in the polymerization was optimized and we found that the particle sizes fall in the range of 30-60 nm. The structural morphology of the uncrosslinked latex represented the most homogeneous image compared to the crosslinked latex. The effect of the amount of crosslinker on the particle sizes investigated by the Zeta-sizer Nano series while Atomic Force microscopy (AFM) was used to study the structural properties of latex nanoparticles.

  13. Syntheses of crosslinked latex nanoparticles using differential microemulsion polymerization

    International Nuclear Information System (INIS)

    Hassmoro, N F; Abdullah, S; Rusop, M

    2013-01-01

    The differential microemulsion polymerization was used to synthesize latex nanoparticles. In this paper, 1, 3-butylene glycol dimethacrylate (1, 3-BGDMA) was used as a crosslinker respectively 1–5 weight% of monomer total. Butyl acrylate (BA), butyl methacrylate (BMA), and methacrylic acid (MAA) was used as the monomer. The thin film of latex nanoparticles were prepared by using spin coating method and have been dried at 100°C for 5 minutes. The amount of the crosslinker added in the polymerization was optimized and we found that the particle sizes fall in the range of 30–60 nm. The structural morphology of the uncrosslinked latex represented the most homogeneous image compared to the crosslinked latex. The effect of the amount of crosslinker on the particle sizes investigated by the Zeta-sizer Nano series while Atomic Force microscopy (AFM) was used to study the structural properties of latex nanoparticles.

  14. A facile route to synthesize nanogels doped with silver nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Coll Ferrer, M. Carme [University of Pennsylvania, Department of Materials Science (United States); Ferrier, Robert C. [University of Pennsylvania, Department of Chemical and Biomolecular Engineering (United States); Eckmann, David M. [University of Pennsylvania, Department of Anesthesiology and Critical Care (United States); Composto, Russell J., E-mail: composto@seas.upenn.edu [University of Pennsylvania, Department of Materials Science (United States)

    2013-01-15

    In this study, we describe a simple method to prepare hybrid nanogels consisting of a biocompatible core-shell polymer host containing silver nanoparticles. First, the nanogels (NG, {approx}160 nm) containing a lysozyme rich core and a dextran rich shell, are prepared via Maillard and heat-gelation reactions. Second, silver nanoparticles (Ag NPs, {approx}5 nm) are synthesized 'in situ' in the NG solution without requiring additional reducing agents. This approach leads to stable Ag NPs located in the NG. Furthermore, we demonstrate that the amount of Ag NPs in the NG can be tuned by varying silver precursor concentration. Hybrid nanogels with silver nanoparticles have potential in antimicrobial, optical, and therapeutic applications.

  15. A facile route to synthesize nanogels doped with silver nanoparticles

    International Nuclear Information System (INIS)

    Coll Ferrer, M. Carme; Ferrier, Robert C.; Eckmann, David M.; Composto, Russell J.

    2013-01-01

    In this study, we describe a simple method to prepare hybrid nanogels consisting of a biocompatible core–shell polymer host containing silver nanoparticles. First, the nanogels (NG, ∼160 nm) containing a lysozyme rich core and a dextran rich shell, are prepared via Maillard and heat-gelation reactions. Second, silver nanoparticles (Ag NPs, ∼5 nm) are synthesized “in situ” in the NG solution without requiring additional reducing agents. This approach leads to stable Ag NPs located in the NG. Furthermore, we demonstrate that the amount of Ag NPs in the NG can be tuned by varying silver precursor concentration. Hybrid nanogels with silver nanoparticles have potential in antimicrobial, optical, and therapeutic applications.

  16. Fast removal of malachite green dye using novel superparamagnetic sodium alginate-coated Fe3O4 nanoparticles.

    Science.gov (United States)

    Mohammadi, Abbas; Daemi, Hamed; Barikani, Mehdi

    2014-08-01

    In this study, superparamagnetic sodium alginate-coated Fe3O4 nanoparticles (Alg-Fe3O4) as a novel magnetic adsorbent were prepared by in situ coprecipitation method, in which Fe3O4 nanoparticles were precipitated from FeCl3 and FeCl2 under alkaline medium in the presence of sodium alginate. The Alg-Fe3O4 nanoparticles were used for removal of malachite green (MG) from aqueous solutions using batch adsorption technique. The characterization of synthesized nanoparticles was performed using XRD, FTIR, TEM, TGA and vibrating sample magnetometer (VSM) techniques. FTIR analysis of synthesized nanoparticles provided the evidence that sodium alginate was successfully coated on the surface of Fe3O4 nanoparticles. The FT-IR and TGA characterization showed that the Alg-Fe3O4 nanoparticles contained about 14% (w/w) of sodium alginate. Moreover, TEM analysis indicated that the average diameter of the Alg-Fe3O4 nanoparticles was about 12nm. The effects of adsorbent dosage, pH and temperature were investigated on the adsorption properties of MG onto Alg-Fe3O4 nanoparticles. The equilibrium adsorption data were modeled using the Langmuir and Freundlich isotherms. The maximum adsorption capacity obtained from Langmuir isotherm equation was 47.84mg/g. The kinetics of adsorption of MG onto Alg-Fe3O4 nanoparticles were investigated using the pseudo-first-order and pseudo-second-order kinetic models. The results showed that the adsorption of MG onto nanoparticles followed pseudo-second-order kinetic model. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. ZnFe2O4 nanoparticles for potential application in radiosensitization

    International Nuclear Information System (INIS)

    Hidayatullah, M; Nurhasanah, I; Budi, W S

    2016-01-01

    Radiosensitizer is a material that can increase the effects of radiation in radiotherapy application. Various materials with high effective atomic number have been developed as a radiosensitizer, such as metal, iron oxide and quantum dot. In this study, ZnFe 2 O 4 nanoparticles are included in iron oxide class were synthesized by precipitation method from the solution of zinc nitrate and ferrite nitrate and followed by calcination at 700° C for 3 hours. The XRD pattern shows that most of the observed peaks can be indexed to the cubic phase of ZnFe 2 O 4 with a lattice parameter of 8.424 Å. SEM image reveals that nanoparticles are the sphere-like shape with size in the range 84-107 nm. The ability of ZnFe 2 O 4 nanoparticles as radiosensitizer was examined by loading those nanoparticles into Escherichia coli cell culture which irradiated with photon energy of 6 MV at a dose of 2 Gy. ZnFe 2 O 4 nanoparticles showed ability to increase the absorbed dose by 0.5 to 1.0 cGy/g. In addition, the presence of 1 g/L ZnFe 2 O 4 nanoparticles resulted in an increase radiation effect by 6.3% higher than if exposed to radiation only. These results indicated that ZnFe 2 O 4 nanoparticles can be used as the radiosensitizer for increasing radiation effect in radiotherapy. (paper)

  18. Synthesis of NiFe2O4 nanoparticles for energy and environment applications

    Science.gov (United States)

    Zhang, Ying; Rimal, Gaurab; Tang, Jinke; Dai, Qilin

    2018-02-01

    Magnetic nanoparticles are of great interest due to their applications in energy and environment. In this work, we developed a chemical solution based method to synthesize NiFe2O4 (NFO) nanoparticles with different sizes and structures by organic ligands and studied their applications in magnetic electrolyte concentration cells and waste water treatment. NFO nanoparticle growth is controlled by the organic passivating ligand ratios, reaction temperatures, and reaction solution concentrations to achieve the control of NFO nanoparticle size ranging from 25 nm to 160 nm. The NFO growth mechanism is controlled by aggregation related mechanism, leading to tunable magnetic properties and concentration cell device performance. Magnetic biochar consisting of biochar/NFO composite was also obtained based on the developed method. Waste water containing Rhodamine B was tested by the synthesized magnetic biochar. We believe the method developed in this work about magnetic NFO nanoparticles and magnetic biochar will shed light on the application of magnetic nanoparticles in energy and environment.

  19. Microstructural characterization of gold nanoparticles synthesized by solution plasma processing

    International Nuclear Information System (INIS)

    Cho, Sung-Pyo; Bratescu, Maria Antoaneta; Takai, Osamu; Saito, Nagahiro

    2011-01-01

    Microstructural characteristics of gold nanoparticles (Au NPs) fabricated by solution plasma processing (SPP) in reverse micelle solutions have been studied by high-resolution transmission electron microscopy (HRTEM). The synthesized Au NPs, with an average size of 6.3 ± 1.4 nm, have different crystal characteristics; fcc single-crystalline particles, multiply twinned particles (MTPs), and incomplete MTPs (single-nanotwinned fcc configuration). The crystal structure characteristics of the Au NPs synthesized by the SPP method were analyzed and compared with similar-size Au NPs obtained by the conventional chemical reduction synthesis (CRS) method. The TEM analysis results show that the Au NPs synthesized by the CRS method have shapes and crystal structures similar to those nanoparticles obtained by the SPP method. However, from the detailed HRTEM analysis, the relative number of the Au MTPs and incomplete MTPs to the total number of the Au NPs synthesized by the SPP method was observed to be around 94%, whereas the relative number of these kinds of crystal structures fabricated by the CRS method was about 63%. It is most likely that the enhanced formation of the Au MTPs is due to the fact that the SPP method generates highly reaction-activated species under low environmental temperature conditions.

  20. Magnetic and catalytic properties of inverse spinel CuFe{sub 2}O{sub 4} nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Anandan, S., E-mail: sanand@nitt.edu [Nanomaterials and Solar Energy Conversion Lab, Department of Chemistry, National Institute of Technology, Trichy 620 015 (India); Department of Environmental Engineering and Science, Feng Chia University, Taichung 407, Taiwan (China); Selvamani, T.; Prasad, G. Guru [Nanomaterials and Solar Energy Conversion Lab, Department of Chemistry, National Institute of Technology, Trichy 620 015 (India); Asiri, A.M. [The Center of Excellence for Advanced Materials Research, King Abdulaziz University, P.O. Box 80203, Jeddah 21413 (Saudi Arabia); Wu, J.J., E-mail: jjwu@fcu.edu.tw [Department of Environmental Engineering and Science, Feng Chia University, Taichung 407, Taiwan (China)

    2017-06-15

    Highlights: • Copper ferrite (CuFe{sub 2}O{sub 4}) nanoparticles were synthesized via citrate-nitrate combustion method. • Spectroscopic information’s have found that CuFe{sub 2}O{sub 4} nanoparticles as an inverse spinel structure. • Magnetic study exhibits CuFe{sub 2}O{sub 4} nanoparticles have ferromagnetic behavior. • CuFe{sub 2}O{sub 4} nanoparticles employed for photocatalytic decolourisation of methylene blue under visible light irradiation. - Abstract: In this research, inverse spinel copper ferrite nanoparticles (CuFe{sub 2}O{sub 4} NPs) were synthesized via citrate-nitrate combustion method. The crystal structure, particle size, morphology and magnetic studies were investigated using various instrumental tools to illustrate the formation of the inverse spinel structure. Mossbauer spectrometry identified Fe is located both in the tetrahedral and octahedral site in the ratio (40:60) and the observed magnetic parameters values such as saturation magnetization (M{sub s} = 20.62 emu g{sup −1}), remnant magnetization (M{sub r} = 11.66 emu g{sup −1}) and coercivity (H{sub c} = 63.1 mTesla) revealed that the synthesized CuFe{sub 2}O{sub 4} NPs have a typical ferromagnetic behaviour. Also tested CuFe{sub 2}O{sub 4} nanoparticles as a photocatalyst for the decolourisation of methylene blue (MB) in the presence of peroxydisulphate as the oxidant.

  1. Optical properties of monodispersive FePt nanoparticle films

    Energy Technology Data Exchange (ETDEWEB)

    Lee, S.J.; Lo, C.C.H. [Ames Laboratory, Iowa State University, Ames, IA 50011 (United States); Yu, A.C.C. [Sony Corporation, Sendai Technology Center, 3-4-1 Sakuragi, Miyagi 985-0842 (Japan); Fan, M. [Center for Sustainable Environmental Technologies, Iowa State University, Ames, IA 50011 (United States)

    2004-10-01

    The optical properties of monodispersive FePt nanoparticle films were investigated using spectroscopic ellipsometry in the energy range of 1.5 to 5.5 eV. The monodispersive FePt nanoparticle film was stabilized on a Si substrate by means of an organosilane coupling film, resulting in the formation of a (Si/SiO{sub 2}/APTS/FePt nanoparticles monolayer) structure. Multilayer optical models were employed to study the contribution of the FePt nanoparticles to the measured optical properties of the monodispersive FePt nanoparticle film, and to estimate the optical properties of the FePt nanoparticle layer. (copyright 2004 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  2. Magnetic anomalies in Fe-doped NiO nanoparticle

    Science.gov (United States)

    Pradeep, R.; Gandhi, A. C.; Tejabhiram, Y.; Mathar Sahib, I. K. Md; Shimura, Y.; Karmakar, L.; Das, D.; Wu, Sheng Yun; Hayakawa, Y.

    2017-09-01

    Undoped and iron-doped NiO nanoparticle were synthesized by standard hydrothermal method. A detailed study is carried out on the effect of dopant concentration on morphology, structural, resonance and magnetic properties of NiO nanoparticle by varying the Fe concentration from 0.01 to 0.10 M. The synchrotron-x-ray diffraction confirmed that no secondary phase was observed other than NiO. The x-ray photoelectron spectroscopy studies revealed that, Fe was primarily in the trivalent state, replacing the Ni2+ ion inside the octahedral crystal site of NiO. The Electron paramagnetic studies revealed the ferromagnetic cluster formation at high doping concentration (5 and 10%). The ZFC-FC curves displayed an average blocking temperature around 180 K due to particle size distribution. The anomalous behaviour of spontaneous exchange bias (H SEB) and magnetic remanence (M r) for all Fe-doped samples observed at 5 K showed an increase (0.1316-0.1384 emu g-1) in the moment of frozen spin (M p) as the dopant concentration increased. The role of frozen spin moment in spontaneous exchange bias behaviour was discussed.

  3. Microbial-Physical Synthesis of Fe and Fe3O4 Magnetic Nanoparticles Using Aspergillus niger YESM1 and Supercritical Condition of Ethanol

    Directory of Open Access Journals (Sweden)

    Mai Abdeen

    2016-01-01

    Full Text Available Magnetic Fe and Fe3O4 (magnetite nanoparticles are successfully synthesized using Aspergillus niger YESM 1 and supercritical condition of liquids. Aspergillus niger is used for decomposition of FeSO4 and FeCl3 to FeS and Fe2O3, respectively. The produced particles are exposed to supercritical condition of ethanol for 1 hour at 300°C and pressure of 850 psi. The phase structure and the morphology measurements yield pure iron and major Fe3O4 spherical nanoparticles with average size of 18 and 50 nm, respectively. The crystal size amounts to 9 nm for Fe and 8 nm for Fe3O4. The magnetic properties are measured to exhibit superparamagnetic- and ferromagnetic-like behaviors for Fe and Fe3O4 nanoparticles, respectively. The saturation magnetization amounts to 112 and 68 emu/g for Fe and Fe3O4, respectively. The obtained results open new route for using the biophysical method for large-scale production of highly magnetic nanoparticles to be used for biomedical applications.

  4. Microbial-Physical Synthesis of Fe and Fe_3O_4 Magnetic Nanoparticles Using Aspergillus niger YESM1 and Supercritical Condition of Ethanol

    International Nuclear Information System (INIS)

    Abdeen, M.; Sabry, S.; Ghozlan, H.; El-Gendy, A. A.; Carpenter, E.E.; El-Gendy, A. A.

    2016-01-01

    Magnetic Fe and Fe_3O_4 (magnetite) nanoparticles are successfully synthesized using Aspergillus niger YESM 1 and supercritical condition of liquids. Aspergillus niger is used for decomposition of FeSO_4 and FeCl_3 to FeS and Fe_2O_3, respectively. The produced particles are exposed to supercritical condition of ethanol for 1 hour at 300 degree and pressure of 850 psi. The phase structure and the morphology measurements yield pure iron and major Fe_3O_4 spherical nanoparticles with average size of 18 and 50 nm, respectively. The crystal size amounts to 9 nm for Fe and 8 nm for Fe_3O_4. The magnetic properties are measured to exhibit superparamagnetic- and ferromagnetic-like behaviors for Fe and Fe_3O_4 nanoparticles, respectively. The saturation magnetization amounts to 112 and 68 emu/g for Fe and Fe_3O_4, respectively. The obtained results open new route for using the biophysical method for large-scale production of highly magnetic nanoparticles to be used for biomedical applications

  5. Ferrofluid synthesis using oleic acid coated Fe3O4 nanoparticles dispersed in mineral oil for heat transfer applications

    Science.gov (United States)

    Imran, Mohd; Rahman Ansari, Akhalakur; Hussain Shaik, Aabid; Abdulaziz; Hussain, Shahir; Khan, Afzal; Rehaan Chandan, Mohammed

    2018-03-01

    Ferrofluids are stable dispersion of iron oxide nanoparticles in a carrier fluid which find potential applications in heat transfer. Fe3O4 nanoparticles of mean size in the range of 5–10 nm were synthesized using conventional co-precipitation method. This work deals with the synthesis of ferrofluids using mineral oil as a carrier fluid and oleic acid coated Fe3O4 nanoparticles as dispersed phase. Morphology (shape and size) and crystallinity of the synthesized nanoparticle is captured using TEM and XRD. Oleic acid coating on nanoparticle is probed using FTIR for confirming the stability of ferrofluid. Thermal properties of mineral oil based ferrofluid with varying concentration of nanoparticles are evaluated in terms of thermal conductivity. It was found that the thermal conductivity of ferrofluid increases upto 2.5% (w/v) nanoparticle loading, where a maximum enhancement of ∼51% in thermal conductivity was recorded as compared to the base fluid.

  6. Hydrothermal synthesis of NiFe2O4 nano-particles: structural ...

    Indian Academy of Sciences (India)

    2. Experimental. In order to synthesize NiFe2O4 nano-particles, Ni(NO3)2· ... Nickel and iron nitrates are dissolved in distilled ... are in good agreement with standard JCPDS: 86-2267. The ... in order to evaluate micro-strain (ε) and crystallite size (D) using the ..... Impedance spectroscopic studies are useful for investigating.

  7. Effects of Fe nanoparticles on bacterial growth and biosurfactant production

    Energy Technology Data Exchange (ETDEWEB)

    Liu Jia; Vipulanandan, Cumaraswamy, E-mail: cvipulanandan@uh.edu [University of Houston, Department of Civil and Environmental Engineering (United States); Cooper, Tim F. [University of Houston, Department of Biology and Biochemistry (United States); Vipulanandan, Geethanjali [University of Houston, Department of Biomedical Engineering (United States)

    2013-01-15

    Environmental conditions can have a major impact on bacterial growth and production of secondary products. In this study, the effect of different concentrations of Fe nanoparticles on the growth of Serratia sp. and on its production of a specific biosurfactant was investigated. The Fe nanoparticles were produced using the foam method, and the needle-shaped nanoparticles were about 30 nm in diameter. It was found that Fe nanoparticles can have either a positive or a negative impact on the bacterial growth and biosurfactant production, depending on their concentration. At 1 mg/L of Fe nanoparticle concentration the bacterial growth increased by 57 % and biosurfactant production increased by 63 %. When the Fe nanoparticle concentration was increased to 1 g/L, the bacterial growth decreased by 77 % and biosurfactant activity was undetectable. The biosurfactant itself was not directly affected by Fe nanoparticles over the range of concentrations studied, indicating that the observed changes in biosurfactant activity resulted indirectly from the effect of nanoparticles on the bacteria. These negative effects with nanoparticle exposures were temporary, demonstrated by the restoration of biosurfactant activity when the bacteria initially exposed to Fe nanoparticles were allowed to regrow in the absence of nanoparticles. Finally, the kinetics of bacterial growth and biosurfactant production were modeled. The model's predictions agreed with the experimental results.

  8. Effects of Fe nanoparticles on bacterial growth and biosurfactant production

    Science.gov (United States)

    Liu, Jia; Vipulanandan, Cumaraswamy; Cooper, Tim F.; Vipulanandan, Geethanjali

    2013-01-01

    Environmental conditions can have a major impact on bacterial growth and production of secondary products. In this study, the effect of different concentrations of Fe nanoparticles on the growth of Serratia sp. and on its production of a specific biosurfactant was investigated. The Fe nanoparticles were produced using the foam method, and the needle-shaped nanoparticles were about 30 nm in diameter. It was found that Fe nanoparticles can have either a positive or a negative impact on the bacterial growth and biosurfactant production, depending on their concentration. At 1 mg/L of Fe nanoparticle concentration the bacterial growth increased by 57 % and biosurfactant production increased by 63 %. When the Fe nanoparticle concentration was increased to 1 g/L, the bacterial growth decreased by 77 % and biosurfactant activity was undetectable. The biosurfactant itself was not directly affected by Fe nanoparticles over the range of concentrations studied, indicating that the observed changes in biosurfactant activity resulted indirectly from the effect of nanoparticles on the bacteria. These negative effects with nanoparticle exposures were temporary, demonstrated by the restoration of biosurfactant activity when the bacteria initially exposed to Fe nanoparticles were allowed to regrow in the absence of nanoparticles. Finally, the kinetics of bacterial growth and biosurfactant production were modeled. The model's predictions agreed with the experimental results.

  9. Effects of Fe nanoparticles on bacterial growth and biosurfactant production

    International Nuclear Information System (INIS)

    Liu Jia; Vipulanandan, Cumaraswamy; Cooper, Tim F.; Vipulanandan, Geethanjali

    2013-01-01

    Environmental conditions can have a major impact on bacterial growth and production of secondary products. In this study, the effect of different concentrations of Fe nanoparticles on the growth of Serratia sp. and on its production of a specific biosurfactant was investigated. The Fe nanoparticles were produced using the foam method, and the needle-shaped nanoparticles were about 30 nm in diameter. It was found that Fe nanoparticles can have either a positive or a negative impact on the bacterial growth and biosurfactant production, depending on their concentration. At 1 mg/L of Fe nanoparticle concentration the bacterial growth increased by 57 % and biosurfactant production increased by 63 %. When the Fe nanoparticle concentration was increased to 1 g/L, the bacterial growth decreased by 77 % and biosurfactant activity was undetectable. The biosurfactant itself was not directly affected by Fe nanoparticles over the range of concentrations studied, indicating that the observed changes in biosurfactant activity resulted indirectly from the effect of nanoparticles on the bacteria. These negative effects with nanoparticle exposures were temporary, demonstrated by the restoration of biosurfactant activity when the bacteria initially exposed to Fe nanoparticles were allowed to regrow in the absence of nanoparticles. Finally, the kinetics of bacterial growth and biosurfactant production were modeled. The model’s predictions agreed with the experimental results.

  10. Electrical, dielectric and photocatalytic properties of Fe-doped ZnO nanomaterials synthesized by sol gel method

    Directory of Open Access Journals (Sweden)

    Yacine Cherif

    2016-09-01

    Full Text Available Fe-doped ZnO nanoparticles were synthesized by sol gel technique. Fine-scale and single phase hexagonal wurtzite structure in all samples were confirmed by SEM and XRD, respectively. The band gap energy depends on the amount of Fe and was found to be in the range of 3.11–2.53 eV. The electric and dielectric properties were investigated using complex impedance spectroscopy. AC conductivity data were correlated with the barrier hopping (CBH model to evaluate the binding energy (Wm, the minimum hopping distance (Rmin and the density of states at Fermi level, N(EF. Fe doping in ZnO also improved the photocatalytic activity. Thus, the sample Zn0.95Fe0.05O showed high degradation potential towards methylene blue (MB, i.e. it degrades 90% of BM in 90 min under UV light.

  11. Morphologic and structural characterization of the CoFe2O4 synthesized by combustion reaction

    International Nuclear Information System (INIS)

    Lima, M.S.; Sousa, J.-P.L.M.L.; Vieira, D.A.; Lira, H.L.; Costa, A.C.F.M.; Sasaki, J.M.

    2009-01-01

    CoFe 2 O 4 powders were synthesized by combustion reaction using glycine as fuel, aiming obtaining nanosized and monophase powders. Thus, different conditions of external heating during the synthesis were investigated. The powders were prepared according to the propellants and explosives theory, using glycine as fuel in the stoichiometric proportion (Φe = 1). During the synthesis the flame temperature and time were measured. The resulting powders were characterized by X-rays diffraction and scanning electronic microscopy (SEM). The results show that the condition in which the synthesis was realized it influences in the combustion flame temperature and time and contributes for the obtainment of powders with majority phase without secondary phases. Crystallite size varied of 33 to 50 nm. All powders presented morphology constituted by soft agglomerated formed by nanoparticles. (author). (author)

  12. Structural and optical properties of NiFe2O4 synthesized via green technology

    Science.gov (United States)

    Patel, S.; Saleem, M.; Varshney, Dinesh

    2018-05-01

    The nanoparticles of NiFe2O4 were successfully synthesized via green technology using banana peel extract as the catalyst as well as the medium for reaction technique is reported. Analysis of X-ray diffraction spectrum revealed the cubic structure for the prepared spinel ferrite samples crystallized into cubic spinel structure with the space group Fd3m. The Retvield refinement was carried out which obeyed the results obtained from the XRD spectrum analysis of the sample. Raman spectrum provided confirmation for the spinel structure formation and five active Raman modes were observed. Since the optical band-gap value shows inverse response to the crystallite size, The UV-Vis spectrum study confirmed dual but reduced band-gap value.

  13. NiCrxFe2− xO4 ferrite nanoparticles and their composites with ...

    Indian Academy of Sciences (India)

    Half of the samples have been sintered at 620°C and the other at 1175°C. Then polypyrrole (PPy)–NiCrFe2-O4 composites have been synthesized by polymerization of pyrrole monomer in the presence of NiCrFe2-O4 nanoparticles. The structure, morphology and magnetic properties of the samples have been ...

  14. Ion beam synthesis of Fe nanoparticles in MgO and yttria-stabilized zirconia

    Science.gov (United States)

    Potzger, K.; Reuther, H.; Zhou, Shengqiang; Mücklich, A.; Grötzschel, R.; Eichhorn, F.; Liedke, M. O.; Fassbender, J.; Lichte, H.; Lenk, A.

    2006-04-01

    To form embedded Fe nanoparticles, MgO(001) and YSZ(001) single crystals have been implanted at elevated temperatures with Fe ions at energies of 100 keV and 110 keV, respectively. The ion fluence was fixed at 6×1016 cm-2. As a result, γ- and α-phase Fe nanoparticles were synthesized inside MgO and YSZ, respectively. A synthesis efficiency of 100% has been achieved for implantation at 1273 K into YSZ. The ferromagnetic behavior of the α-Fe nanoparticles is reflected by a magnetic hyperfine field of 330 kOe and a hysteretic magnetization reversal. Electron holography showed a fringing magnetic field around some, but not all of the particles.

  15. Ion beam synthesis of Fe nanoparticles in MgO and yttria-stabilized zirconia

    International Nuclear Information System (INIS)

    Potzger, K.; Reuther, H.; Zhou, Shengqiang; Muecklich, A.; Groetzschel, R.; Eichhorn, F.; Liedke, M. O.; Fassbender, J.; Lichte, H.; Lenk, A.

    2006-01-01

    To form embedded Fe nanoparticles, MgO(001) and YSZ(001) single crystals have been implanted at elevated temperatures with Fe ions at energies of 100 keV and 110 keV, respectively. The ion fluence was fixed at 6x10 16 cm -2 . As a result, γ- and α-phase Fe nanoparticles were synthesized inside MgO and YSZ, respectively. A synthesis efficiency of 100% has been achieved for implantation at 1273 K into YSZ. The ferromagnetic behavior of the α-Fe nanoparticles is reflected by a magnetic hyperfine field of 330 kOe and a hysteretic magnetization reversal. Electron holography showed a fringing magnetic field around some, but not all of the particles

  16. A Study On Dispersion Stability Of Nickel Nanoparticles Synthesized By Wire Explosion In Liquid Media

    OpenAIRE

    Kim C.K.; Lee G.-J.; Lee M.K.; Rhee C.K.

    2015-01-01

    In this study, nickel nanoparticles were synthesized in ethanol using portable pulsed wire evaporation, which is a one-step physical method. From transmission electron microscopy images, it was found that the Ni nanoparticles exhibited a spherical shape with an average diameter of 7.3 nm. To prevent aggregation of the nickel nanoparticles, a polymer surfactant was added into the ethanol before the synthesis of nickel nanoparticles, and adsorbed on the freshly synthesized nickel nanoparticles ...

  17. Preparation, characterization and SRXPS study of polyvinyl alcohol modified Fe3O4 nanoparticles

    International Nuclear Information System (INIS)

    Li Ming; Wang Bing; Feng Weiyue; Liu Hui; Kang Yanjie; Kui Rexi

    2011-01-01

    In this study, Fe 3 O 4 nanoparticles were coated with PVA to synthesize PVA-Fe 3 O 4 complex, which were characterized by transmission electron microscopy(TEM),thermo gravimetric(TG) analysis, UV-vis spectra,zeta potentials and ICP-MS, in terms of the physicochemical properties, while surface constituents, structures and chemical bonds of the modified and unmodified nanoparticles were characterized with synchrotron radiation X-ray photoelectron spectroscopy(SRXPS), for exploring modification mechanism of the PVA-Fe 3 O 4 . The results indicate that after PVA modification, the suspension stability of Fe 3 O 4 nanoparticles in water and cellular uptake capability were significantly improved compared with unmodified Fe 3 O 4 . The SRXPS analysis reveals that the hydroxy groups on the surface of Fe 3 O 4 nanoparticles and PVA were combined by hydrogen bond to consist a stable system, which would be beneficial to the biomedical applications of Fe 3 O 4 nanoparticles. (authors)

  18. Antibacterial effect of bismuth subsalicylate nanoparticles synthesized by laser ablation

    International Nuclear Information System (INIS)

    Flores-Castañeda, Mariela; Vega-Jiménez, Alejandro L.; Almaguer-Flores, Argelia; Camps, Enrique; Pérez, Mario; Silva-Bermudez, Phaedra; Berea, Edgardo; Rodil, Sandra E.

    2015-01-01

    The antimicrobial properties of bismuth subsalicylate (BSS) nanoparticles against four opportunistic pathogens; E. coli, P. aeruginosa, S. aureus, and S. epidermidis were determined. BSS nanoparticles were synthesized by pulse laser ablation of a solid target in distilled water under different conditions. The nanoparticles were characterized using high-resolution transmission electron microscopy and absorption spectra and small angle X-ray scattering. The analysis shows that the colloids maintained the BSS structure and presented average particle size between 20 and 60 nm, while the concentration ranges from 95 to 195 mg/L. The antibacterial effect was reported as the inhibition ratio of the bacterial growth after 24 h and the cell viability was measured using the XTT assay. The results showed that the inhibition ratio of E. coli and S. epidermidis was dependant on the NPs size and/or concentration, meanwhile P. aeruginosa and S. aureus were more sensitive to the BSS nanoparticles independently of both the size and the concentration. In general, the BSS colloids with average particle size of 20 nm were the most effective, attaining inhibition ratios >80 %, similar or larger than those obtained with the antibiotic used as control. The results suggest that the BSS colloids could be used as effective antibacterial agents with potential applications in the medical area

  19. Antibacterial effect of bismuth subsalicylate nanoparticles synthesized by laser ablation

    Science.gov (United States)

    Flores-Castañeda, Mariela; Vega-Jiménez, Alejandro L.; Almaguer-Flores, Argelia; Camps, Enrique; Pérez, Mario; Silva-Bermudez, Phaedra; Berea, Edgardo; Rodil, Sandra E.

    2015-11-01

    The antimicrobial properties of bismuth subsalicylate (BSS) nanoparticles against four opportunistic pathogens; E. coli, P. aeruginosa, S. aureus, and S. epidermidis were determined. BSS nanoparticles were synthesized by pulse laser ablation of a solid target in distilled water under different conditions. The nanoparticles were characterized using high-resolution transmission electron microscopy and absorption spectra and small angle X-ray scattering. The analysis shows that the colloids maintained the BSS structure and presented average particle size between 20 and 60 nm, while the concentration ranges from 95 to 195 mg/L. The antibacterial effect was reported as the inhibition ratio of the bacterial growth after 24 h and the cell viability was measured using the XTT assay. The results showed that the inhibition ratio of E. coli and S. epidermidis was dependant on the NPs size and/or concentration, meanwhile P. aeruginosa and S. aureus were more sensitive to the BSS nanoparticles independently of both the size and the concentration. In general, the BSS colloids with average particle size of 20 nm were the most effective, attaining inhibition ratios >80 %, similar or larger than those obtained with the antibiotic used as control. The results suggest that the BSS colloids could be used as effective antibacterial agents with potential applications in the medical area.

  20. Antibacterial effect of bismuth subsalicylate nanoparticles synthesized by laser ablation

    Energy Technology Data Exchange (ETDEWEB)

    Flores-Castañeda, Mariela [Instituto Nacional de Investigaciones Nucleares (Mexico); Vega-Jiménez, Alejandro L., E-mail: argelia.almaguer@mac.com; Almaguer-Flores, Argelia [Universidad Nacional Autónoma de México, Facultad de Odontología, DEPeI, I (Mexico); Camps, Enrique; Pérez, Mario [Instituto Nacional de Investigaciones Nucleares (Mexico); Silva-Bermudez, Phaedra [Instituto Nacional de Rehabilitación, Unidad de Ingeniería de Tejidos, Terapia Celular y Medicina Regenerativa (Mexico); Berea, Edgardo [FarmaQuimia SA de CV. (Mexico); Rodil, Sandra E. [Universidad Nacional Autónoma de México, Instituto de Investigaciones en Materiales (Mexico)

    2015-11-15

    The antimicrobial properties of bismuth subsalicylate (BSS) nanoparticles against four opportunistic pathogens; E. coli, P. aeruginosa, S. aureus, and S. epidermidis were determined. BSS nanoparticles were synthesized by pulse laser ablation of a solid target in distilled water under different conditions. The nanoparticles were characterized using high-resolution transmission electron microscopy and absorption spectra and small angle X-ray scattering. The analysis shows that the colloids maintained the BSS structure and presented average particle size between 20 and 60 nm, while the concentration ranges from 95 to 195 mg/L. The antibacterial effect was reported as the inhibition ratio of the bacterial growth after 24 h and the cell viability was measured using the XTT assay. The results showed that the inhibition ratio of E. coli and S. epidermidis was dependant on the NPs size and/or concentration, meanwhile P. aeruginosa and S. aureus were more sensitive to the BSS nanoparticles independently of both the size and the concentration. In general, the BSS colloids with average particle size of 20 nm were the most effective, attaining inhibition ratios >80 %, similar or larger than those obtained with the antibiotic used as control. The results suggest that the BSS colloids could be used as effective antibacterial agents with potential applications in the medical area.

  1. Synthesis and characterization of Fe3O4 nanoparticles coated with fucan polysaccharides

    International Nuclear Information System (INIS)

    Silva, V.A.J.; Andrade, P.L.; Silva, M.P.C.; Bustamante D, A.; De Los Santos Valladares, Luis; Albino Aguiar, J.

    2013-01-01

    In this work we report the preparation of fucan-coated magnetite (Fe 3 O 4 ) nanoparticles by the co-precipitation method. These nanoparticles were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, Mössbauer spectroscopy and magnetic measurements. The nanoparticles showed quasi-spherical morphology with mean sizes around 10 nm. XRD and FT-IR confirmed the functionalization of the Fe 3 O 4 nanoparticles with the fucan polysaccharide. Room temperature magnetization measurements and Mössbauer spectroscopy showed that the nanoparticles exhibited superparamagnetic behavior at 300 K and the magnetic properties of the Fe 3 O 4 are partly screened by the coating preventing aggregation. - Highlights: • Syntheses of fucan-coated Fe 3 O 4 nanoparticles were made by co-precipitation method. • The efficiency of polysaccharide coated was analyzed by XRD and FT-IR. • The magnetic nanoparticles mean size was 10–20 nm. • The fucan-coated magnetite nanoparticles showed superparamagnetic behavior

  2. Cobalt surface modification during γ-Fe{sub 2}O{sub 3} nanoparticle synthesis by chemical-induced transition

    Energy Technology Data Exchange (ETDEWEB)

    Li, Junming [School of Physical Science and Technology, Southwest University, Chongqing 400715 (China); Li, Jian, E-mail: aizhong@swu.edu.cn [School of Physical Science and Technology, Southwest University, Chongqing 400715 (China); Chen, Longlong; Lin, Yueqiang; Liu, Xiaodong; Gong, Xiaomin [School of Physical Science and Technology, Southwest University, Chongqing 400715 (China); Li, Decai [School of Mechanical and Control Engineering, Beijing Jiaotong University, Beijing 100044 (China)

    2015-02-01

    In the chemical-induced transition of FeCl{sub 2} solution, the FeOOH/Mg(OH){sub 2} precursor was transformed into spinel structured γ-Fe{sub 2}O{sub 3} crystallites, coated with a FeCl{sub 3}·6H{sub 2}O layer. CoCl{sub 2} surface modified γ-Fe{sub 2}O{sub 3} nanoparticles were prepared by adding Co(NO{sub 3}){sub 2} during the synthesis. CoFe{sub 2}O{sub 4} modified γ-Fe{sub 2}O{sub 3} nanoparticles were prepared by adding NaOH during the surface modification with Co(NO{sub 3}){sub 2}. The CoFe{sub 2}O{sub 4} layer grew epitaxially on the γ-Fe{sub 2}O{sub 3} crystallite to form a composite crystallite, which was coated by CoCl{sub 2}·6H{sub 2}O. The composite could not be distinguished using X-ray diffraction or transmission electron microscopy, since CoFe{sub 2}O{sub 4} and γ-Fe{sub 2}O{sub 3} possess similar spinel structures and lattice constants. X-ray photoelectron spectroscopy was used to distinguish them. The saturation magnetization and coercivity of the spinel structured γ-Fe{sub 2}O{sub 3}-based nanoparticles were related to the grain size. - Highlights: • γ-Fe{sub 2}O{sub 3} nanoparticles were synthesized by chemical induced transition. • CoCl{sub 2} modified nanoparticles were prepared by additional Co(NO{sub 3}){sub 2} during synthesization. • CoFe{sub 2}O{sub 4} modified nanoparticles were prepared by additional Co(NO{sub 3}){sub 2} and NaOH. • The magnetism of the nanoparticles is related to the grain size.

  3. Cobalt surface modification during γ-Fe2O3 nanoparticle synthesis by chemical-induced transition

    International Nuclear Information System (INIS)

    Li, Junming; Li, Jian; Chen, Longlong; Lin, Yueqiang; Liu, Xiaodong; Gong, Xiaomin; Li, Decai

    2015-01-01

    In the chemical-induced transition of FeCl 2 solution, the FeOOH/Mg(OH) 2 precursor was transformed into spinel structured γ-Fe 2 O 3 crystallites, coated with a FeCl 3 ·6H 2 O layer. CoCl 2 surface modified γ-Fe 2 O 3 nanoparticles were prepared by adding Co(NO 3 ) 2 during the synthesis. CoFe 2 O 4 modified γ-Fe 2 O 3 nanoparticles were prepared by adding NaOH during the surface modification with Co(NO 3 ) 2 . The CoFe 2 O 4 layer grew epitaxially on the γ-Fe 2 O 3 crystallite to form a composite crystallite, which was coated by CoCl 2 ·6H 2 O. The composite could not be distinguished using X-ray diffraction or transmission electron microscopy, since CoFe 2 O 4 and γ-Fe 2 O 3 possess similar spinel structures and lattice constants. X-ray photoelectron spectroscopy was used to distinguish them. The saturation magnetization and coercivity of the spinel structured γ-Fe 2 O 3 -based nanoparticles were related to the grain size. - Highlights: • γ-Fe 2 O 3 nanoparticles were synthesized by chemical induced transition. • CoCl 2 modified nanoparticles were prepared by additional Co(NO 3 ) 2 during synthesization. • CoFe 2 O 4 modified nanoparticles were prepared by additional Co(NO 3 ) 2 and NaOH. • The magnetism of the nanoparticles is related to the grain size

  4. Spectroscopic ellipsometry study of FePt nanoparticle films

    Energy Technology Data Exchange (ETDEWEB)

    Lee, S.J.; Lo, C.C.H. [Ames Laboratory, Iowa State University, Ames, IA 50011 (United States); Yu, A.C.C. [Sony Corporation, Sendai Technology Center, 3-4-1 Sakuragi, Miyagi 985-0842 (Japan); Fan, M. [School of Materials Science and Technology, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States)

    2006-12-15

    The optical properties of a FePt nanoparticle film were investigated using spectroscopic ellipsometry. The FePt nanoparticle film of thickness about 15 nm was prepared by deposition of FePt nanoparticles directly on a Si substrate. The nanoparticle film was annealed at 600 C in vacuum for two hours before the measurements. The optical properties of the FePt nanoparticle film showed distinctively different spectra from those obtained from the bulk and thin film FePt samples, in particular in the low photon energy range (below 3.5 eV) where the nanoparticle film exhibited a relatively flat refractive index and a substantially lower extinction coefficient than the bulk and epitaxial thin film samples. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  5. A newly developed Fe-doped calcium sulfide nanoparticles with magnetic property for cancer hyperthermia

    Science.gov (United States)

    Wu, Steven Yueh-Hsiu; Tseng, Ching-Li; Lin, Feng-Huei

    2010-05-01

    In this study, a magnetic iron-doped calcium sulfide (Fe-CaS) nanoparticle was newly developed and studied for the purpose of hyperthermia due to its promising magnetic property, adequate biodegradation rate, and relatively good biocompatibility. Fe-CaS nanoparticles were synthesized by a wet chemical co-precipitation process with heat treatment in a N2 atmosphere, and were subsequently cooled in N2 and exposed to air at a low temperature. The crystal structure of the Fe-CaS nanoparticles was similar to that of the CaS, which was identified by an X-ray diffractometer (XRD). The particle size was less than 40 nm based on a Debye-Scherrer equation and transmission electron microscope (TEM) examination. Magnetic properties obtained from the SQUID magnetometer demonstrated that the synthesized CaS was a diamagnetic property. Once the Fe ions were doped, the synthesized Fe-CaS converted into paramagnetism which showed no hysteresis loop. Having been heated above 600 °C in N2, the Fe-CaS showed a promising magnetic property to produce enough energy to increase the temperature for hyperthermia. 10 mg/ml of the Fe-CaS was able to generate heat to elevate the media temperature over 42.5 °C within 6 min. The area of the hysteresis loop increased with the increasing of the treated temperature, especially at 800 °C for 1 h. This is because more Fe ions replaced Ca ions in the lattice at the higher heat treatment temperature. The heat production was also increasing with the increasing of heat treatment temperature, which resulted in an adequate specific absorption ratio (SAR) value, which was found to be 45.47 W/g at 37 °C under an alternative magnetic field of f = 750 KHz , H = 10 Oe. The in vitro biocompatibility test of the synthesized Fe-CaS nanoparticles examined by the LDH assay showed no cytotoxicity to 3T3 fibroblast. The result of in vitro cell hyperthermia shows that under magnetic field the Fe-CaS nanoparticles were able to generate heat and kill the CT-26 cancer

  6. A newly developed Fe-doped calcium sulfide nanoparticles with magnetic property for cancer hyperthermia

    International Nuclear Information System (INIS)

    Wu, Steven Yueh-Hsiu; Tseng, Ching-Li; Lin, Feng-Huei

    2010-01-01

    In this study, a magnetic iron-doped calcium sulfide (Fe-CaS) nanoparticle was newly developed and studied for the purpose of hyperthermia due to its promising magnetic property, adequate biodegradation rate, and relatively good biocompatibility. Fe-CaS nanoparticles were synthesized by a wet chemical co-precipitation process with heat treatment in a N 2 atmosphere, and were subsequently cooled in N 2 and exposed to air at a low temperature. The crystal structure of the Fe-CaS nanoparticles was similar to that of the CaS, which was identified by an X-ray diffractometer (XRD). The particle size was less than 40 nm based on a Debye-Scherrer equation and transmission electron microscope (TEM) examination. Magnetic properties obtained from the SQUID magnetometer demonstrated that the synthesized CaS was a diamagnetic property. Once the Fe ions were doped, the synthesized Fe-CaS converted into paramagnetism which showed no hysteresis loop. Having been heated above 600 o C in N 2 , the Fe-CaS showed a promising magnetic property to produce enough energy to increase the temperature for hyperthermia. 10 mg/ml of the Fe-CaS was able to generate heat to elevate the media temperature over 42.5 o C within 6 min. The area of the hysteresis loop increased with the increasing of the treated temperature, especially at 800 o C for 1 h. This is because more Fe ions replaced Ca ions in the lattice at the higher heat treatment temperature. The heat production was also increasing with the increasing of heat treatment temperature, which resulted in an adequate specific absorption ratio (SAR) value, which was found to be 45.47 W/g at 37 o C under an alternative magnetic field of f = 750 KHz, H = 10 Oe. The in vitro biocompatibility test of the synthesized Fe-CaS nanoparticles examined by the LDH assay showed no cytotoxicity to 3T3 fibroblast. The result of in vitro cell hyperthermia shows that under magnetic field the Fe-CaS nanoparticles were able to generate heat and kill the CT-26

  7. Green Synthesis of Magnetite (Fe3O4) Nanoparticles Using Seaweed ( Kappaphycus alvarezii) Extract

    Science.gov (United States)

    Yew, Yen Pin; Shameli, Kamyar; Miyake, Mikio; Kuwano, Noriyuki; Bt Ahmad Khairudin, Nurul Bahiyah; Bt Mohamad, Shaza Eva; Lee, Kar Xin

    2016-06-01

    In this study, a simple, rapid, and eco-friendly green method was introduced to synthesize magnetite nanoparticles (Fe3O4-NPs) successfully. Seaweed Kappaphycus alvarezii ( K. alvarezii) was employed as a green reducing and stabilizing agents. The synthesized Fe3O4-NPs were characterized with X-ray diffraction (XRD), ultraviolet-visible spectroscopy (UV-Vis), Fourier transform infrared (FT-IR), and transmission electron microscopy (TEM) techniques. The X-ray diffraction planes at (220), (311), (400), (422), (511), (440), and (533) were corresponding to the standard Fe3O4 patterns, which showed the high purity and crystallinity of Fe3O4-NPs had been synthesized. Based on FT-IR analysis, two characteristic absorption peaks were observed at 556 and 423 cm-1, which proved the existence of Fe3O4 in the prepared nanoparticles. TEM image displayed the synthesized Fe3O4-NPs were mostly in spherical shape with an average size of 14.7 nm.

  8. Facilely synthesized Fe2O3–graphene nanocomposite as novel electrode materials for supercapacitors with high performance

    International Nuclear Information System (INIS)

    Wang, Zhuo; Ma, Chunyan; Wang, Hailin; Liu, Zonghuai; Hao, Zhengping

    2013-01-01

    Graphical abstract: Fe 2 O 3 Graphene nanocomposite was synthesized in a simple hydrothermal way by using urea to adjust the system pH value, by this method the reduction of graphite oxide and the formation of Fe 2 O 3 nanocomposite are finished in one step. The specific capacitance of the Fe 2 O 3 Graphene electrode reached 226 F/g at a discharge current density of 1 A g –1 . Highlights: ► The Fe 2 O 3 –graphene nanocomposite was obtained by friendly method with urea in one step. ► The addition of Fe 2 O 3 composites has positive effect on the electrical performance of the graphene nanosheets. ► The specific capacitance of the Fe 2 O 3 –graphene electrode was 226 F/g at a discharge current density of 1 A g −1 . -- Abstract: Fe 2 O 3 –graphene nanocomposite with high capacitive properties had been prepared friendly and facilely by hydrothermal method in one-step. The morphology and structure of the obtained material were examined by X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET) and transmission electron microscope (TEM) techniques. It was revealed by TEM images that Fe 2 O 3 nanoparticles grow well on the surface of graphene and the formation of Fe 2 O 3 nanoparticles hinders the aggregation of graphene (reduced graphene oxide, namely, RGO). Electrochemical properties of the synthesized materials were characterized by serials of electrochemical measurements in 1 M Na 2 SO 4 electrolyte. Fe 2 O 3 –graphene nanocomposite electrode show higher specific capacitance than graphene, indicating an accelerative effect of Fe 2 O 3 and graphene on improving the electrochemical performance of the electrode. The specific capacitance of Fe 2 O 3 –graphene nanocomposite is 226 F/g at a current density of 1 A/g. These attractive results indicate it is possible to seek and develop the promising, environmentally benign and commercial electrodes material based on Fe 2 O 3 and graphene

  9. Strengthening mechanisms of Fe nanoparticles for single crystal Cu–Fe alloy

    International Nuclear Information System (INIS)

    Shi, Guodong; Chen, Xiaohua; Jiang, Han; Wang, Zidong; Tang, Hao; Fan, Yongquan

    2015-01-01

    A single crystal Cu–Fe alloy with finely dispersed precipitate Fe nanoparticles was fabricated in this study. The interface relationship of iron nanoparticle and copper matrix was analyzed with a high-resolution transmission electron microscope (HRTEM), and the effect of Fe nanoparticles on mechanical properties of single crystal Cu–Fe alloy was discussed. Results show that, the finely dispersed Fe nanoparticles can be obtained under the directional solidification condition, with the size of 5–50 nm and the coherent interface between the iron nanoparticle and the copper matrix. Single crystal Cu–Fe alloy possesses improved tensile strength of 194.64 MPa, and total elongation of 44.72%, respectively, at room temperature, in contrast to pure Cu sample. Nanoparticles which have coherent interface with matrix can improve the dislocation motion state. Some dislocations can slip through the nanoparticle along the coherent interface and some dislocations can enter into the nanoparticles. Thus to improve the tensile strength of single crystal Cu–Fe alloy without sacrificing the ductility simultaneously. Based on the above analyses, strengthening mechanisms of Fe nanoparticles for single crystal Cu–Fe alloy was described

  10. Controllable synthesis and characterization of Fe3O4/Au composite nanoparticles

    International Nuclear Information System (INIS)

    Xing, Yan; Jin, Yan-Yan; Si, Jian-Chao; Peng, Ming-Li; Wang, Xiao-Fang; Chen, Chao; Cui, Ya-Li

    2015-01-01

    Fe 3 O 4 /Au composite nanoparticles (GoldMag NPs) have received considerable attention because of their advantageous properties arisen from both individual Au and Fe 3 O 4 nanoparticles. Many efforts have been devoted to the synthesis of these composite nanoparticles. Herein, GoldMag NPs were reported to be synthesized by two-step method. Fe 3 O 4 nanoparticles were prepared by co-precipitation and modified by the citric acid, and then citric acid-coated Fe 3 O 4 nanoparticles were used as seeds in sodium citrate solution to reduce the HAuCl 4 . The size of obtained nanoparticles was geared from 25 to 300 nm by controlling the concentration of reactants. The GoldMag NPs were characterized by UV–vis spectrometer, dynamic light scattering (DLS), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and vibrating sample magnetometer (VSM). The GoldMag NPs showed good superparamagnetism at room temperature and were well dispersed in water with surface plasmon resonance absorption peak varied from 538 nm to 570 nm. - Highlights: • A low cost, simple manipulation and nontoxic approach was designed for preparation of magnetic Fe 3 O 4 /Au (GoldMag NPs) nanocomposites. • The size of GoldMag NPs could be controlled from 25 to 300 nm by varying the concentration of reactants. • GoldMag NPs possessed good magnetic response, high dispersion, and good stability

  11. Influence of Fe-doping on the structural, optical and magnetic properties of ZnO nanoparticles

    International Nuclear Information System (INIS)

    Liu Changzhen; Meng Dawei; Pang Haixia; Wu Xiuling; Xie Jing; Yu Xiaohong; Chen Long; Liu Xiaoyang

    2012-01-01

    Zn 1–x Fe x O (x=0–0.05) nanoparticles were synthesized without a catalyst by a two-step method. Fe was doped into ZnO by a source of metallic Fe sheets in a solid–liquid system at 80 °C, and the Zn 1−x Fe x O nanoparticles were obtained by annealing at 300 °C. X-ray diffraction, X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy were used to characterize the structural properties of the as-grown Zn 1−x Fe x O. The optical properties were determined by Infrared and Ultraviolet–visible spectroscopy. The results confirm that the crystallinity of the ZnO is deteriorated due to Fe-doping. XPS results show that there is a mixture of Fe 0+ and the Fe 3+ in the representative Zn 0.95 Fe 0.05 O sample. The optical band gap of Zn 1−x Fe x O is enhanced with increasing of Fe-doping. Room temperature ferromagnetism was observed in all the Fe-doped ZnO samples. - Highlights: ► Zn 1−x Fe x O nanoparticles were synthesized with a simple two-step method. ► The Zn 1−x Fe x O predecessors were synthesized at a low temperature. ► Fe element was readily doped from the source of metallic Fe sheet. ► All the Fe doping ZnO samples have room temperature ferromagnetism. ► The structural and properties of the Zn 1−x Fe x O are regular with different x.

  12. Comparison on Bactericidal and Cytotoxic Effect of Silver Nanoparticles Synthesized by Different Methods

    Science.gov (United States)

    Mala, R.; Celsia, A. S. Ruby; Malathi Devi, S.; Geerthika, S.

    2017-08-01

    Biologically synthesized silver nanoparticle are biocompatible for medical applications. The present work is aimed to synthesize silver nanoparticle using the fruit pulp of Tamarindusindica and to evaluate its antibacterial and anticancer activity against lung cancercell lines. Antibacterial activity was assessed by well diffusion method. Cytotoxicity was evaluated using MTT assay. GC-MS of fruit pulp extract showed the presence of levoglucosenone, n-hexadecanoic acid, 9,12-octadecadienoic acid etc. Antioxidant activity of the fruit pulp was determined by DPPH assay, hydrogen peroxide scavenging assay and lipid peroxidation. The size of biologically synthesized silver nanoparticle varied from 50 nm to 76 nm. It was 59 nm to 98 nm for chemically synthesized silver nanoparticle. Biologically synthesized silver nanoparticle showed 26 mm inhibition zone against E. coli and chemically synthesized silver nanoparticle showed 20 mm. Antioxidant activity of fruit extract by DPPH showed 84 % reduction. The IC 50 of biologically synthesized silver nanoparticle against lung cancer cell lines was 48 µg/ml. It was 95 µg/ml for chemically synthesized silver nanoparticle. The increased activity of biologically synthesized silver nanoparticle was due to its smaller size, stability and the bioactive compounds capping the silver nanoparticle extracted from the fruit extract.

  13. Sol-gel synthesis of 8 nm magnetite (Fe 3O 4) nanoparticles and their magnetic properties

    KAUST Repository

    Lemine, O. M.

    2012-10-01

    Magnetite (Fe 3O 4) nanoparticles were successfully synthesized by a sol-gel method. The obtained nanoparticles were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), energy dispersive analysis by X-ray (EDAX), transmission electron microscopy (TEM), superconducting quantum interference device (SQUID) and Mössbauer spectrometry. XRD and Mössbauer measurements indicate that the obtained nanoparticles are single phase. TEM analysis shows the presence of spherical nanoparticles with homogeneous size distribution of about 8 nm. Room temperature ferromagnetics behavior was confirmed by SQUID measurements. The mechanism of nanoparticles formation and the comparison with recent results are discussed. Finally, the synthesized nanoparticles present a potential candidate for hyperthermia application given their saturation magnetization. © 2012 Elsevier Ltd. All rights reserved.

  14. Sol-gel synthesis of 8 nm magnetite (Fe 3O 4) nanoparticles and their magnetic properties

    KAUST Repository

    Lemine, O. M.; Omri, Karim; Zhang, Bei; El Mir, Lassaad; Sajieddine, Mohammed; Alyamani, Ahmed Y.; Bououdina, M.

    2012-01-01

    Magnetite (Fe 3O 4) nanoparticles were successfully synthesized by a sol-gel method. The obtained nanoparticles were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), energy dispersive analysis by X-ray (EDAX), transmission electron microscopy (TEM), superconducting quantum interference device (SQUID) and Mössbauer spectrometry. XRD and Mössbauer measurements indicate that the obtained nanoparticles are single phase. TEM analysis shows the presence of spherical nanoparticles with homogeneous size distribution of about 8 nm. Room temperature ferromagnetics behavior was confirmed by SQUID measurements. The mechanism of nanoparticles formation and the comparison with recent results are discussed. Finally, the synthesized nanoparticles present a potential candidate for hyperthermia application given their saturation magnetization. © 2012 Elsevier Ltd. All rights reserved.

  15. Studies on magnetic properties of chemically synthesized crystalline calcium ferrite nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Debnath, A., E-mail: debnathanimesh@gmail.com [Department of Civil Engineering, National Institute of Technology Agartala, Jirania, West Tripura, 799046 India (India); Bera, A.; Saha, B. [Department of Physics, National Institute of Technology Agartala, Jirania, West Tripura 799046 (India); Chattopadhyay, K. K. [Department of Physics, Jadavpur University, Kolkata 700 032 (India)

    2016-05-23

    Spinel-type ferrites have taken a very important role for modern electronic industry. Most of these ferrites exhibit low-loss dielectric properties, high resistivity, low eddy current and also high temperature ferromagnetism. Calcium ferrite is one such important metal oxide which is environmentally safe, chemically stable, low cost and greatly abundant. This outstanding material of calcium ferrite is synthesized by a simple chemical precipitation method using NaOH as the precipitating agent. Ferric chloride anhydrous (FeCl{sub 3}) and Calcium chloride dihydrate (CaCl{sub 2}.2H{sub 2}O) were used as iron and calcium sources respectively. The samples were heated at 200°C for 8h to obtain homogeneous powder of Calcium ferrite. The powders were characterized by using X-ray diffraction (XRD), field emission scanning electron microscope (FESEM), Transmission electrical microscopy (TEM), and Fourier transform infrared spectroscopic (FTIR) measurements. The polycrystalline nature of the sample was confirmed by X-ray diffraction study. The magnetic properties of the sample were investigated by vibrating sample magnetometer (VSM) measurements. Magnetization curve of the prepared sample depicts that as synthesized calcium ferrite nanoparticles have saturation magnetic moment of 1.74 emu/g and the coercivity of 35.08 Oe with superparamagnetic behavior. The synthesized calcium ferrite nanoparticles with such magnetic properties will be a candidate material for different applications in electronics and exploring its functionality in the field of recently developing semiconductor device physics and spintronics.

  16. Studies on magnetic properties of chemically synthesized crystalline calcium ferrite nanoparticles

    International Nuclear Information System (INIS)

    Debnath, A.; Bera, A.; Saha, B.; Chattopadhyay, K. K.

    2016-01-01

    Spinel-type ferrites have taken a very important role for modern electronic industry. Most of these ferrites exhibit low-loss dielectric properties, high resistivity, low eddy current and also high temperature ferromagnetism. Calcium ferrite is one such important metal oxide which is environmentally safe, chemically stable, low cost and greatly abundant. This outstanding material of calcium ferrite is synthesized by a simple chemical precipitation method using NaOH as the precipitating agent. Ferric chloride anhydrous (FeCl_3) and Calcium chloride dihydrate (CaCl_2.2H_2O) were used as iron and calcium sources respectively. The samples were heated at 200°C for 8h to obtain homogeneous powder of Calcium ferrite. The powders were characterized by using X-ray diffraction (XRD), field emission scanning electron microscope (FESEM), Transmission electrical microscopy (TEM), and Fourier transform infrared spectroscopic (FTIR) measurements. The polycrystalline nature of the sample was confirmed by X-ray diffraction study. The magnetic properties of the sample were investigated by vibrating sample magnetometer (VSM) measurements. Magnetization curve of the prepared sample depicts that as synthesized calcium ferrite nanoparticles have saturation magnetic moment of 1.74 emu/g and the coercivity of 35.08 Oe with superparamagnetic behavior. The synthesized calcium ferrite nanoparticles with such magnetic properties will be a candidate material for different applications in electronics and exploring its functionality in the field of recently developing semiconductor device physics and spintronics.

  17. Nanostructural and magnetic studies of virtually monodispersed NiFe2O4 nanocrystals synthesized by a liquid–solid-solution assisted hydrothermal route

    International Nuclear Information System (INIS)

    Li Xinghua; Tan Guoguo; Chen Wei; Zhou Baofan; Xue Desheng; Peng Yong; Li, Fashen; Mellors, Nigel J.

    2012-01-01

    This study presents a comprehensively and systematically structural, chemical and magnetic characterization of ∼9.5 nm virtually monodispersed nickel ferrite (NiFe 2 O 4 ) nanoparticles prepared using a modified liquid–solid-solution (LSS) assisted hydrothermal method. Lattice-resolution scanning transmission electron microscope (STEM) and converged beam electron diffraction pattern (CBED) techniques are adapted to characterize the detailed spatial morphology and crystal structure of individual NiFe 2 O 4 particles at nano scale for the first time. It is found that each NiFe 2 O 4 nanoparticle is single crystal with an fcc structure. The morphology investigation reveals that the prepared NiFe 2 O 4 nanoparticles of which the surfaces are decorated by oleic acid are dispersed individually in hexane. The chemical composition of nickel ferrite nanoparticles is measured to be 1:2 atomic ratio of Ni:Fe, indicating a pure NiFe 2 O 4 composition. Magnetic measurements reveal that the as-synthesized nanocrystals displayed superparamagnetic behavior at room temperature and were ferromagnetic at 10 K. The nanoscale characterization and magnetic investigation of monodispersed NiFe 2 O 4 nanoparticles should be significant for its potential applications in the field of biomedicine and magnetic fluid using them as magnetic materials.

  18. Phytosynthesis and photocatalytic activity of magnetite (Fe_3O_4) nanoparticles using the Andean blackberry leaf

    International Nuclear Information System (INIS)

    Kumar, Brajesh; Smita, Kumari; Cumbal, Luis; Debut, Alexis; Galeas, Salome; Guerrero, Victor H.

    2016-01-01

    In the present study, a simple, low cost, and ecofriendly synthesis of magnetite nanoparticles (Fe_3O_4 NPs) has been developed using Andean blackberry leaf extract. UV–vis spectroscopy technique were used to study the initial formation of Fe_3O_4 NPs. Morphology, crystallinity and surface properties of nanoparticles were studied using transmission electron microscopy (TEM), Dynamic light scattering (DLS), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and Thermal gravimetric (TG) techniques. TEM and DLS characterization indicated the formation of spherical Fe_3O_4 NPs of average size 54.5 ± 24.6 nm. XRD and FTIR studies confirmed the existence of the cubic spinel phase of Fe_3O_4 NPs and Fe−O peak at 570 cm"−"1, whereas TG analysis indicated that the nanoparticles contain 94% metal and 6% capping ligand. It has been observed that, as-synthesized Fe_3O_4 NPs exhibited photocatalytic activity for degradation of organic dyes such as methylene blue (k = 0.0105475 min"−"1), congo red (k = 0.0043240 min"−"1), and methyl orange (k = 0.0028930 min"−"1), efficiently. The antioxidant activity of Fe_3O_4 NPs against 1, 1-diphenyl-2-picrylhydrazyl were also evaluated. - Highlights: • We report extracellular phytosynthesis of Fe_3O_4 nanoparticles using the Andean blackberry leaf. • The synthesized Fe_3O_4 nanoparticles are spherical and average size is 54.5 ± 24.6 nm. • It showed enhanced photocatalytic activity and weak antioxidant efficacy. • Environmentally benign, non-toxic and cost-effective method is suggested.

  19. Microwave-Assisted Synthesis of CuFe2O4 Nanoparticles and Starch-Based Magnetic Nanocomposites

    Directory of Open Access Journals (Sweden)

    Gh. Nabiyouni

    2013-06-01

    Full Text Available Magnetic CuFe2O4 nanoparticles were synthesized by a facile microwave-assisted reaction between Cu(NO32 and Fe(NO33. The magnetic nanoparticles were added to starch to make magnetic polymeric nanocomposite. The nanoparticles and nanocomposites were characterized using X-ray diffraction and scanning electron microscopy. The magnetic properties of the samples were investigated using an alternating gradient force magnetometer (AGFM. The copper ferrite nanoparticles exhibited ferromagnetic behavior at room temperature, with a saturation magnetization of 29emu/g and a coercivity of 136 Oe. The distribution of the CuFe2O4 nanoparticles into the polymeric matrixes decreases the coercivity (136 Oe to 66 Oe. The maximum coercivity of 82 Oe was found for 15% of CuFe2O4 distributed to the starch matrix.

  20. The influence of oxidation process on exchange bias in egg-shaped FeO/Fe{sub 3}O{sub 4} core/shell nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Leszczyński, Błażej, E-mail: b.leszczynski@amu.edu.pl [NanoBioMedical Centre, Adam Mickiewicz University, Umultowska 85, 61-614 Poznań (Poland); Faculty of Physics, Adam Mickiewicz University, Umultowska 85, 61-614 Poznań (Poland); Hadjipanayis, George C.; El-Gendy, Ahmed A. [Department of Physics and Astronomy, University of Delaware, 217 Sharp Lab, Newark, DE 19716 (United States); Załęski, Karol [NanoBioMedical Centre, Adam Mickiewicz University, Umultowska 85, 61-614 Poznań (Poland); Śniadecki, Zbigniew [Institute of Molecular Physics, Polish Academy of Sciences, M. Smoluchowskiego 17, 60-179 Poznań (Poland); Musiał, Andrzej [NanoBioMedical Centre, Adam Mickiewicz University, Umultowska 85, 61-614 Poznań (Poland); Institute of Molecular Physics, Polish Academy of Sciences, M. Smoluchowskiego 17, 60-179 Poznań (Poland); Jarek, Marcin [NanoBioMedical Centre, Adam Mickiewicz University, Umultowska 85, 61-614 Poznań (Poland); Jurga, Stefan [NanoBioMedical Centre, Adam Mickiewicz University, Umultowska 85, 61-614 Poznań (Poland); Faculty of Physics, Adam Mickiewicz University, Umultowska 85, 61-614 Poznań (Poland); Skumiel, Andrzej [Faculty of Physics, Adam Mickiewicz University, Umultowska 85, 61-614 Poznań (Poland)

    2016-10-15

    Egg-shaped nanoparticles with a core–shell morphology were synthesized by thermal decomposition of an iron oleate complex. XRD and M(T) magnetic measurements confirmed the presence of FeO (wustite) and Fe{sub 3}O{sub 4} (magnetite) phases in the nanoparticles. Oxidation of FeO to Fe{sub 3}O{sub 4} was found to be the mechanism for the shell formation. As-made nanoparticles exhibited high values of exchange bias at 2 K. Oxidation led to decrease of exchange field from 2880 Oe (in as-made sample) to 330 Oe (in oxidized sample). At temperatures higher than the Néel temperature of FeO (200 K) there was no exchange bias. An interesting observation was made showing the exchange field to be higher than the coercive field at temperatures close to magnetite's Verwey transition. - Highlights: • Synthesis of monodispersed FeO nanoparticles is shown. • As-made FeO nanoparticle is antiferromagnetically ordered, when it is oxidized to Fe{sub 3}O{sub 4}, the FeO core becomes small and disordered. • Exchange bias in well-ordered and disordered core is different.

  1. Spectroscopic and Electrochemical Properties of Lithium-Rich LiFePO4 Cathode Synthesized by Solid-State Reaction

    Science.gov (United States)

    Rosaiah, P.; Hussain, O. M.; Zhu, Jinghui; Qiu, Yejun

    2017-08-01

    Lithium iron phosphate (Li x FePO4) is synthesized by a solid-state reaction method. The structural, electrical and electrochemical properties are studied in detail. It is found that the increment of lithium concentration (up to x = 1.05) does not affect the structure of LiFePO4 but improves its electrical conductivity as well as electrochemical performance. Surface morphological studies exhibited the formation of rod-like nanoparticles with small size. Electric and dielectric properties are also investigated over a frequency range of 1 Hz-1 MHz at different temperatures. The conductivity increased with increasing temperature, which follows the Arrhenius relation with the activation energy of about 0.31 eV. And the electrochemical tests found that the Li1.05FePO4 cathode possessed improved discharge capacity with better cycling performance.

  2. Microemulsion synthesis and magnetic properties of Fe{sub x}Ni{sub (1−x)} alloy nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Beygi, H., E-mail: hossein.beygi@stu-mail.um.ac.ir; Babakhani, A.

    2017-01-01

    This paper investigates synthesis of Fe{sub x}Ni{sub (1−x)} bimetallic nanoparticles by microemulsion method. Through studying the mechanism of nanoparticles formation, it is indicated that synthesis of nanoparticles took placed by simultaneous reduction of metal ions and so nanoparticles structure is homogeneous alloy. Fe{sub x}Ni{sub (1−x)} nanoparticles with different sizes, morphologies and compositions were synthesized by changing the microemulsion parameters such as water/surfactant/oil ratio, presence of co-surfactant and NiCl{sub 2}·6H{sub 2}O to FeCl{sub 2}·4H{sub 2}O molar ratio. Synthesized nanoparticles were characterized by transmission electron microscopy, particle size analysis, X-ray diffraction, atomic absorption and thermogravimetric analyses. The results indicated that, presence of butanol as co-surfactant led to chain-like arrangement of nanoparticles. Also, finer nanoparticles were synthesized by decreasing the amount of oil and water and increasing the amount of CTAB. The results of vibrating sample magnetometer suggested that magnetic properties of Fe{sub x}Ni{sub (1−x)} alloy nanoparticles were affected by composition, size and morphology of the particles. Spherical and chain-like Fe{sub x}Ni{sub (1−x)} alloy nanoparticles were superparamagnetic and ferromagnetic, respectively. Furthermore, higher iron in the composition of nanoparticles increases the magnetic properties. - Highlights: • Fe{sub x}Ni{sub (1−x)} alloy NPs synthesized by simultaneous metal ions reduction in microemulsion. • Finer NPs synthesized at lower amount of oil and water and higher amount of CTAB. • Chain-like Fe{sub x}Ni{sub (1−x)} NPs are ferromagnetic; higher aspect ratio, more magnetization. • Spherical Fe{sub x}Ni({sub 1−x)} NPs with smaller size (7 nm) are superparamagnetic. • Spherical Fe{sub x}Ni{sub (1−x)} nanoparticles with higher x had increased magnetic properties.

  3. Effect of annealing on the structure of chemically synthesized SnO_2 nanoparticles

    International Nuclear Information System (INIS)

    Singh, Kulwinder; Kumar, Akshay; Kumar, Virender; Vij, Ankush; Kumari, Sudesh; Thakur, Anup

    2016-01-01

    Tin oxide (SnO_2) nanoparticles have been synthesized by co-precipitation method. The synthesized nanoparticles were characterized by X-ray diffraction (XRD) and Raman spectroscopy. XRD analysis confirmed the single phase formation of SnO_2 nanoparticles. The Raman shifts showed the typical feature of the tetragonal phase of the as-synthesized SnO_2 nanoparticles. At low annealing temperature, a strong distortion of the crystalline structure and high degree of agglomeration was observed. It is concluded that the crystallinity of SnO_2 nanoparticles improves with the increase in annealing temperature.

  4. A green chemistry approach for synthesizing biocompatible gold nanoparticles

    Science.gov (United States)

    Gurunathan, Sangiliyandi; Han, JaeWoong; Park, Jung Hyun; Kim, Jin-Hoi

    2014-05-01

    Gold nanoparticles (AuNPs) are a fascinating class of nanomaterial that can be used for a wide range of biomedical applications, including bio-imaging, lateral flow assays, environmental detection and purification, data storage, drug delivery, biomarkers, catalysis, chemical sensors, and DNA detection. Biological synthesis of nanoparticles appears to be simple, cost-effective, non-toxic, and easy to use for controlling size, shape, and stability, which is unlike the chemically synthesized nanoparticles. The aim of this study was to synthesize homogeneous AuNPs using pharmaceutically important Ganoderma spp . We developed a simple, non-toxic, and green method for water-soluble AuNP synthesis by treating gold (III) chloride trihydrate (HAuCl4) with a hot aqueous extract of the Ganoderma spp . mycelia. The formation of biologically synthesized AuNPs (bio-AuNPs) was characterized by ultraviolet (UV)-visible absorption spectroscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), energy dispersive X-ray (EDX), dynamic light scattering (DLS), and transmission electron microscopy (TEM). Furthermore, the biocompatibility of as-prepared AuNPs was evaluated using a series of assays, such as cell viability, lactate dehydrogenase leakage, and reactive oxygen species generation (ROS) in human breast cancer cells (MDA-MB-231). The color change of the solution from yellow to reddish pink and strong surface plasmon resonance were observed at 520 nm using UV-visible spectroscopy, and that indicated the formation of AuNPs. DLS analysis revealed the size distribution of AuNPs in liquid solution, and the average size of AuNPs was 20 nm. The size and morphology of AuNPs were investigated using TEM. The biocompatibility effect of as-prepared AuNPs was investigated in MDA-MB-231 breast cancer cells by using various concentrations of AuNPs (10 to 100 μM) for 24 h. Our findings suggest that AuNPs are non-cytotoxic and biocompatible. To the best of our knowledge

  5. Composition tunable cobalt–nickel and cobalt–iron alloy nanoparticles below 10 nm synthesized using acetonated cobalt carbonyl

    International Nuclear Information System (INIS)

    Schooneveld, Matti M. van; Campos-Cuerva, Carlos; Pet, Jeroen; Meeldijk, Johannes D.; Rijssel, Jos van; Meijerink, Andries; Erné, Ben H.; Groot, Frank M. F. de

    2012-01-01

    A general organometallic route has been developed to synthesize Co x Ni 1−x and Co x Fe 1−x alloy nanoparticles with a fully tunable composition and a size of 4–10 nm with high yield. In contrast to previously reported synthesis methods using dicobalt octacarbonyl (Co 2 (CO) 8 ), here the cobalt–cobalt bond in the carbonyl complex is first broken with anhydrous acetone. The acetonated compound, in the presence of iron carbonyl or nickel acetylacetonate, is necessary to obtain small composition tunable alloys. This new route and insights will provide guidelines for the wet-chemical synthesis of yet unmade bimetallic alloy nanoparticles.

  6. Effect of the Fe Nanoparticles Generated by Pulsed Plasma in Liquid in the Catalyzed Ozone Removal of Phenolphthalein

    Directory of Open Access Journals (Sweden)

    O. Olea-Mejia

    2017-01-01

    Full Text Available We have synthesized, in this work, zero valent iron (ZVI nanoparticles to improve the efficiency of degradation of phenolphthalein catalyzed by ozone in aqueous solution. The Fe nanoparticles were obtained using the pulsed plasma in liquid (PPL method with water as the liquid medium. Such nanoparticles have a mean size of 12 nm and are composed of ~80% Fe0, while the rest are a mixture of Fe+2 and Fe+3 oxides. The degradation of phenolphthalein was carried on a glass reactor injecting a constant amount of ozone and introducing different concentrations of Fe nanoparticles to the system. When using pure ozone, the percentage of degradation of phenolphthalein measured by colorimetry after one hour of reaction was 84%. However, when Fe nanoparticles are used, such percentage can be as high as 98% in 50 minutes of reaction. Furthermore, the degradation rate constant was 0.0334 min−1 with only ozone and it can be as high as 0.0733 min−1 with Fe nanoparticles. Finally, the total mineralization of phenolphthalein was obtained by total organic carbon (TOC determinations. It is shown that when using only ozone, we obtained a percentage of mineralization of 49% and 96% when using the highest concentration of Fe nanoparticles.

  7. One-step green synthesis of bimetallic Fe/Pd nanoparticles used to degrade Orange II

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Fang; Yang, Die; Chen, Zuliang, E-mail: zuliang.chen@newcastle.edu.au; Megharaj, Mallavarapu; Naidu, Ravendra

    2016-02-13

    Highlights: • Green synthesis of bimetallic Fe/Pd NPs was firstly reported using the one-step method. • 98.0% of Orange II was removed by Fe/Pd NPs, but only 16.0% by Fe NPs. • Fe/Pd NPs with a diameter ranging from 10 to 100 nm were observed. • Removing Orange II using Fe/Pd NPs involved both adsorption and catalytic degradation. - Abstract: To reduce cost and enhance reactivity, bimetallic Fe/Pd nanoparticles (NPs) were firstly synthesized using grape leaf aqueous extract to remove Orange II. Green synthesized bimetallic Fe/Pd NPs (98.0%) demonstrated a far higher ability to remove Orange II in 12 h compared to Fe NPs (16.0%). Meanwhile, all precursors, e.g., grape leaf extract, Fe{sup 2+} and Pd{sup 2+}, had no obvious effect on removing Orange II since less than 2.0% was removed. Kinetics study revealed that the removal rate fitted well to the pseudo-first-order reduction and pseudo-second-order adsorption model, meaning that removing Orange II via Fe/Pd NPs involved both adsorption and catalytic reduction. The remarkable stability of Fe/Pd NPs showed the potential application for removing azo dyes. Furthermore, Scanning Electron Microscopy (SEM) and Fourier Transform Infrared Spectroscopy (FTIR) confirmed the changes in Fe/Pd NPs before and after reaction with Orange II. High Performance Liquid Chromatography–Mass Spectrum (HPLC–MS) identified the degraded products in the removal of Orange II, and finally a removal mechanism was proposed. This one-step strategy using grape leaf aqueous extract to synthesize Fe/Pd NPs is simple, cost-effective and environmentally benign, making possible the large-scale production of Fe/Pd NPs for field remediation.

  8. Effect of Synthesis Parameters on the Structure and Magnetic Properties of Magnetic Manganese Ferrite/Silver Composite Nanoparticles Synthesized by Wet Chemistry Method

    DEFF Research Database (Denmark)

    Huy, L.T.; Tam, L.T.; Phan, V.N.

    2016-01-01

    In the present work, magnetic manganese ferrite/silver (MnFe2O4-Ag) composite nanoparticles were synthesized by wet chemistry method. This synthesis process consists of two steps: first, the seed of manganese ferrite nanoparticles (MnFe2O4 NPs) was prepared by a coprecipitationmethod; second......, growth of silver nanoparticles (AgNPs) on the MnFe2O4 seed by modified photochemical reaction. We have conducted systematically the effects of synthesis parameters such as pH value, synthesis time, precursor salts concentration, mass ratio and stabilizing agents on the structure and magnetic properties......-prepared MnFe2O4-Ag magnetic nanocomposites display excellent properties of high crystallinity, long-term aggregation stability in aqueous medium, large saturation magnetization in the range of 15-20 emu/g, and small sizes of Ag-NPs similar to 20 nm. These exhibited properties made the MnFe2O4-Ag...

  9. Synthesis and characterization of magnetic Fe/CNTs composites with controllable Fe nanoparticle concentration

    International Nuclear Information System (INIS)

    Zhao Fan; Duan Hongyan; Wang Weigao; Wang Jun

    2012-01-01

    Fe/CNTs composites, with different concentrations of Fe nanoparticles (NPs) on carbon nanotube (CNT) surfaces, were successfully fabricated via a facile solvothermal method. The lengths of CNTs are up to 10 μm and the mean diameter of the Fe nanoparticles is about 25 nm. The structures, composition and magnetic properties of the Fe/CNTs were characterized by XRD, FTIR, FE-SEM, TEM and PPMS. We found that the concentrations of Fe nanoparticles depositing on the CNTs could be controlled by adjusting the initial mass ratio of ferrocene to CNTs. The Fe/CNTs composites display good ferromagnetic properties at room temperature, with a saturation magnetization of 125 emu/g-Fe and a coercivity of 276 Oe. The Curie temperature of the sample is about 1038 K, slightly lower than that (1043 K) of the bulk iron.

  10. Thermal decomposition study of Mn doped Fe3O4 nanoparticles

    Science.gov (United States)

    Malek, Tasmira J.; Chaki, S. H.; Tailor, J. P.; Deshpande, M. P.

    2016-05-01

    Fe3O4 is an excellent magnetic material among iron oxides. It has a cubic inverse spinel structure exhibiting distinguished electric and magnetic properties. In this paper the authors report the synthesis of Mn doped Fe3O4 nanoparticles by wet chemical reduction technique at ambient temperature and its thermal characterization. Ferric chloride hexa-hydrate (FeCl3•6H2O), manganese chloride tetra-hydrate (MnCl2•4H2O) and sodium boro-hydrate (NaBH4) were used for synthesis of Fe3O4 nanoparticles at ambient temperature. The elemental composition of the as-synthesized Mn doped Fe3O4 nanoparticles were determined by energy dispersive analysis of X-rays (EDAX) technique. Thermogravimetric (TG) and differential thermal analysis (DTA) were carried out on the Mn doped Fe3O4 nanoparticles in the temperature range of ambient to 1124 K. The thermo-curves revealed that the particles decompose by four steps. The kinetic parameters were evaluated using non-mechanistic equations for the thermal decomposition.

  11. Magnetic properties of nanocrystalline CoFe{sub 2}O{sub 4} synthesized by thermal plasma in large scale

    Energy Technology Data Exchange (ETDEWEB)

    Nawale, A.B.; Kanhe, N.S. [Department of Physics, University of Pune, Pune 411007 (India); Patil, K.R. [Center for Materials Characterizations, National Chemical Laboratory, Dr. Hommi Bhabha Road, Pashan, Pune 411008 (India); Reddy, V.R.; Gupta, A. [UGC-DAE Consortium for Scientific Research, Indore Centre, University Campus, Khandwa Road, Indore 452 017 (India); Kale, B.B. [Center for Materials for Electronics Technology, Department of Information Technology, Government of India, Panchawati, Off Pashan Road, Pune 411008 (India); Bhoraskar, S.V. [Department of Physics, University of Pune, Pune 411007 (India); Mathe, V.L., E-mail: vlmathe@physics.unipune.ac.in [Department of Physics, University of Pune, Pune 411007 (India); Das, A.K. [Laser and Plasma Technology Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India)

    2012-12-14

    The paper reports the large scale synthesis of nanoparticles of CoFe{sub 2}O{sub 4} using thermal plasma reactor by gas phase condensation method. The yield of formation was found to be around 15 g h{sup -1}. The magnetic properties of CoFe{sub 2}O{sub 4}, synthesized at different reactor powers, were investigated in view of studying the effect of operating parameters of plasma reactor on the structural reorganization leading to the different cation distribution. The values of saturation magnetization, coercivity and remanent magnetization were found to be influenced by input power in thermal plasma. Although the increase in saturation magnetization was marginal (61 emu g{sup -1} to 70 emu g{sup -1}) with increasing plasma power; a significant increase in the coercivity (552 Oe to 849 Oe) and remanent magnetization (16 emu g{sup -1} to 26 emu g{sup -1}) were also noticed. The Moessbauer spectra showed mixed spinel structure and canted spin order for the as synthesized nanoparticles. The detailed analysis of cation distribution using the Moessbauer spectroscopy and X-ray photoelectron spectroscopy leads to the conclusion that the sample synthesized at an optimized power shows the different site selective states. -- Highlights: Black-Right-Pointing-Pointer A rapid synthesis method for synthesizing magnetic nanoparticles of cobalt ferrite. Black-Right-Pointing-Pointer The average particle size ranges between 25 and 40 nm; as revealed by the FESEM analysis. Black-Right-Pointing-Pointer Magnetic properties are influenced by different operating parameters.

  12. Biogenic silver and gold nanoparticles synthesized using red ginseng root extract, and their applications.

    Science.gov (United States)

    Singh, Priyanka; Kim, Yeon Ju; Wang, Chao; Mathiyalagan, Ramya; El-Agamy Farh, Mohamed; Yang, Deok Chun

    2016-05-01

    In the present study, we report a green methodology for the synthesis of silver and gold nanoparticles, using the root extract of the herbal medicinal plant Korean red ginseng. The silver and gold nanoparticles were synthesized within 1 h and 10 min respectively. The nanoparticles generated were not aggregated, and remained stable for a long time, which suggests the nature of nanoparticles. The phytochemicals and ginsenosides present in the root extract assist in reducing and stabilizing the synthesized nanoparticles. The red ginseng root extract-generated silver nanoparticles exhibit antimicrobial activity against pathogenic microorganisms including Vibrio parahaemolyticus, Staphylococcus aureus, Bacillus cereus, and Candida albicans. In addition, the silver nanoparticles exhibit biofilm degrading activity against S. aureus and Pseudomonas aeruginosa. Thus, the present study opens up a new possibility of synthesizing silver and gold nanoparticles in a green and rapid manner using Korean red ginseng root extract, and explores their biomedical applications.

  13. Characterization of Newly Synthesized ZrFe2O5 Nanomaterial and Investigations of Its Tremendous Photocatalytic Properties under Visible Light Irradiation

    Directory of Open Access Journals (Sweden)

    Shaukat Ali Shahid

    2013-01-01

    Full Text Available High functional ZrFe2O5 nanoparticles were synthesized using coprecipitation technique. The chemical composition of nanomaterials was studied by energy-dispersive X-ray (EDX. To observe the morphology, field emission scanning electron microscopy (FE-SEM was used. X-ray diffraction (XRD technique was utilized to appraise the structure of the synthesized material. The photocatalytic behavior of ZrFe2O5 nano-particles was investigated by measuring the degradation rate of toluidine blue O (TBO dye in aqueous solution in the presence of ZrFe2O5 nano-particles under visible light irradiation. A steady decrease in absorption peak under visible light irradiation was observed by increasing exposure time. The degradation efficiency was observed as 92% after 140 min of exposure to visible light. Besides, ZrFe2O5 nanophotocatalyst could be recovered and recycled easily. The rate of TBO and total organic carbon (TOC removal under visible light irradiation decreased by only 5% and 10%, respectively, after seven cycles of use, demonstrating the high photostability of the synthesized nano-photocatalyst material.

  14. Green synthesis of Fe nanoparticles using eucalyptus leaf extracts for treatment of eutrophic wastewater

    International Nuclear Information System (INIS)

    Wang, Ting; Jin, Xiaoying; Chen, Zuliang; Megharaj, Mallavarapu; Naidu, Ravendra

    2014-01-01

    Iron nanoparticles were firstly synthesized through a one-step room-temperature biosynthetic route using eucalyptus leaf extracts (EL-Fe NPs). Scanning electron microscopy (SEM) and X-ray energy-dispersive spectrometer (EDS) confirmed the successful synthesis of the spheroidal iron nanoparticles. Furthermore, X-ray diffraction (XRD) and Fourier Transform Infrared spectrometer (FTIR) indicated that some polyphenols are bound to the surfaces of EL-Fe NPs as a capping/stabilizing agent. Reactivity of EL-Fe NPs was evaluated for the treatment of swine wastewater and results indicated that 71.7% of total N and 84.5% of COD were removed, respectively. This demonstrated the tremendous potential of EL-Fe NPs for in situ remediation of eutrophic wastewater. - Highlights: •Fe NPs were firstly synthesized through a one-step using eucalyptus leaf extracts. •Fe NPs was evaluated by remediating swine wastewater. •71.7% of total N and 84.5% of COD was removed. •Fe NPs for in situ remediation of eutrophic wastewater

  15. Green synthesis of Fe nanoparticles using eucalyptus leaf extracts for treatment of eutrophic wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Ting; Jin, Xiaoying [School of Environmental Science and Engineering, Fujian Normal University, Fuzhou 350007, Fujian (China); Chen, Zuliang, E-mail: Zuliang.chen@unisa.edu.au [School of Environmental Science and Engineering, Fujian Normal University, Fuzhou 350007, Fujian (China); Centre for Environmental Risk Assessment and Remediation, University of South Australia, Mawson Lakes, SA 5095 (Australia); Cooperative Research Centre for Contamination Assessment and Remediation of Environments, Mawson Lakes, SA 5095 (Australia); Megharaj, Mallavarapu; Naidu, Ravendra [Centre for Environmental Risk Assessment and Remediation, University of South Australia, Mawson Lakes, SA 5095 (Australia); Cooperative Research Centre for Contamination Assessment and Remediation of Environments, Mawson Lakes, SA 5095 (Australia)

    2014-01-01

    Iron nanoparticles were firstly synthesized through a one-step room-temperature biosynthetic route using eucalyptus leaf extracts (EL-Fe NPs). Scanning electron microscopy (SEM) and X-ray energy-dispersive spectrometer (EDS) confirmed the successful synthesis of the spheroidal iron nanoparticles. Furthermore, X-ray diffraction (XRD) and Fourier Transform Infrared spectrometer (FTIR) indicated that some polyphenols are bound to the surfaces of EL-Fe NPs as a capping/stabilizing agent. Reactivity of EL-Fe NPs was evaluated for the treatment of swine wastewater and results indicated that 71.7% of total N and 84.5% of COD were removed, respectively. This demonstrated the tremendous potential of EL-Fe NPs for in situ remediation of eutrophic wastewater. - Highlights: •Fe NPs were firstly synthesized through a one-step using eucalyptus leaf extracts. •Fe NPs was evaluated by remediating swine wastewater. •71.7% of total N and 84.5% of COD was removed. •Fe NPs for in situ remediation of eutrophic wastewater.

  16. Microstructural and optical properties of Ca and Cr doped cobalt ferrite nanoparticles synthesized by auto combustion

    Science.gov (United States)

    Agrawal, Shraddha; Parveen, Azra; Azam, Ameer

    2018-05-01

    The Ca and Cr doped cobalt ferrite nanoparticles (Co0.8Ca0.2) (Fe0.8 Cr0.2)2O4 were synthesized by auto combustion method. Microstructural studies were carried out by X-ray diffraction (XRD). The crystalline size of synthesized nanoparticles as determined by the XRD was found to be 17.6 nm. These structural studies suggest that the crystal system remains spinal even with the doping of calcium and chromium. Optical properties of Ca and Cr doped cobalt ferrite were studied by UV-visible technique in the range of 200-800 nm. The energy band gap was calculated with the help of Tauc relationship. Ca and Cr doped cobalt ferrite annealed at 600°C exhibit significant dispersion in complex permeability. The dielectric constant and dielectric loss of cobalt ferrite were studied as a function of frequency and were explained on the basis of Koop's theory based on Maxwell Wagner two layer models and electron hopping.

  17. Biogenic ZnO nanoparticles synthesized using L. aculeata leaf ...

    Indian Academy of Sciences (India)

    The antifungal activity of ZnO nanoparticles were determined using the well diffusion method. All the ... 1. Introduction. Nanoparticles have gained increasing importance because ... The synthesis of nanoparticles by conventional physical.

  18. Effects of Au/Fe and Fe nanoparticles on Serratia bacterial growth and production of biosurfactant

    International Nuclear Information System (INIS)

    Liu, Jia; Vipulanandan, Cumaraswamy

    2013-01-01

    The overall objective of this study was to compare the effects of Au/Fe and Fe nanoparticles on the growth and performance of Serratia Jl0300. The nanoparticle effect was quantified not only by the bacterial growth on agar plate after 1 hour interaction with the nanoparticles, but also by its production of a biosurfactant from used vegetable oil. The nanoparticles were prepared using the foam method. The concentrations of the nanoparticles used for the bacterial interaction study were varied from 1 mg/L to 1 g/L. The test results showed that the effect of nanoparticles on the bacterial growth and biosurfactant production varied with nanoparticle type, concentrations, and interaction time with the bacteria. Au/Fe nanoparticles didn't show toxicity to Serratia after short time (1 h) exposure, while during 8 days fermentation Au/Fe nanoparticles inhibited the growth of Serratia as well as the biosurfactant production when the concentration of the nanoparticles was higher than 10 mg/L. Fe nanoparticles showed inhibition effects to bacterial growth both after short time and long time interaction with Serratia, as well as to biosurfactant production when its concentration was higher than 100 mg/L. Based on the trends observed in this study, analytical models have been developed to predict the bacterial growth and biosurfactant production with varying concentrations of nanoparticles. - Highlights: • Modeled the effect of nanoparticles on the bacterial growth and biosurfactant production. • Effects of Au/Fe nonoparticles on Serratia Bacterial Growth and Production of Biosurfactant. • Scanning Electron Micrograph of bacteria-nanoparticles interaction

  19. Effects of Au/Fe and Fe nanoparticles on Serratia bacterial growth and production of biosurfactant

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Jia; Vipulanandan, Cumaraswamy, E-mail: cvipulanandan@uh.edu

    2013-10-15

    The overall objective of this study was to compare the effects of Au/Fe and Fe nanoparticles on the growth and performance of Serratia Jl0300. The nanoparticle effect was quantified not only by the bacterial growth on agar plate after 1 hour interaction with the nanoparticles, but also by its production of a biosurfactant from used vegetable oil. The nanoparticles were prepared using the foam method. The concentrations of the nanoparticles used for the bacterial interaction study were varied from 1 mg/L to 1 g/L. The test results showed that the effect of nanoparticles on the bacterial growth and biosurfactant production varied with nanoparticle type, concentrations, and interaction time with the bacteria. Au/Fe nanoparticles didn't show toxicity to Serratia after short time (1 h) exposure, while during 8 days fermentation Au/Fe nanoparticles inhibited the growth of Serratia as well as the biosurfactant production when the concentration of the nanoparticles was higher than 10 mg/L. Fe nanoparticles showed inhibition effects to bacterial growth both after short time and long time interaction with Serratia, as well as to biosurfactant production when its concentration was higher than 100 mg/L. Based on the trends observed in this study, analytical models have been developed to predict the bacterial growth and biosurfactant production with varying concentrations of nanoparticles. - Highlights: • Modeled the effect of nanoparticles on the bacterial growth and biosurfactant production. • Effects of Au/Fe nonoparticles on Serratia Bacterial Growth and Production of Biosurfactant. • Scanning Electron Micrograph of bacteria-nanoparticles interaction.

  20. Preparation of chitosan-stabilized Fe{sup 0} nanoparticles for removal of hexavalent chromium in water

    Energy Technology Data Exchange (ETDEWEB)

    Geng, Bing [Key Laboratory of Pollution Processes and Environmental Criteria, Ministry of Education, College of Environmental Science and Engineering, Nankai University, Tianjin 300071 (China); Jin, Zhaohui, E-mail: jinzh@nankai.edu.cn [Key Laboratory of Pollution Processes and Environmental Criteria, Ministry of Education, College of Environmental Science and Engineering, Nankai University, Tianjin 300071 (China); Li, Tielong; Qi, Xinhua [Key Laboratory of Pollution Processes and Environmental Criteria, Ministry of Education, College of Environmental Science and Engineering, Nankai University, Tianjin 300071 (China)

    2009-09-01

    Chitosan-stabilized Fe{sup 0} nanoparticles (CTO-Fe{sup 0}) and Fe{sup 0} nanoparticles synthesized in ethanol-water mixed system (EW-Fe{sup 0}) were tested for reduction of Cr(VI) in water. Fourier transform infrared (FTIR) study suggested that nitrogen and oxygen atoms are the binding sites for chitosan on iron which was accountable for the stability of Fe{sup 0} nanoparticles. While the EW-Fe{sup 0} ignites spontaneously when exposed to air, the CTO-Fe{sup 0} was still in zero valence state after exposure to air over 2-month period as shown by X-ray powder diffraction patterns. Batch experiments demonstrated that the maximum Cr(VI) reduction rates for CTO-Fe{sup 0} was about 3 times higher than EW-Fe{sup 0}. Characterizations with high-resolution X-ray photoelectron spectroscopy (HR-XPS) revealed that Cr(VI) was reduced to Cr(III) and Fe(III) was the only component present on the Fe{sup 0} nanoparticles surface. Additionally, chitosan can inhibited the formation of Fe(III)-Cr(III) precipitation due to its high ability to chelate Fe(III) which resulted in k{sub obs} for CTO-Fe{sup 0} was about 1-3 times higher than EW-Fe{sup 0}. Due to the fast reaction kinetics and good stability against oxidation in air, the chitosan-stabilized Fe{sup 0} nanoparticles have the potential to become an effective agent for in situ subsurface environment remediation.

  1. Natural Fe3O4 nanoparticles embedded zinc–tellurite glasses: Polarizability and optical properties

    International Nuclear Information System (INIS)

    Widanarto, W.; Sahar, M.R.; Ghoshal, S.K.; Arifin, R.; Rohani, M.S.; Hamzah, K.; Jandra, M.

    2013-01-01

    Modifying the optical behavior of zinc–tellurite glass by embedding magnetic nanoparticles has implication in nanophotonics. A series of zinc–tellurite glasses containing natural Fe 3 O 4 nanoparticles with composition (80 − x)TeO 2 ·xFe 3 O 4 ·20ZnO (0 ≤ x ≤ 2) in mol% are synthesized by melt quenching method and their optical properties are investigated using FTIR and UV–vis–NIR spectroscopies. Lorentz–Lorenz relations are exploited to determine the refractive index, molar refraction and electronic polarizability. The sharp absorption peaks of FTIR spectra show a shift from 667 cm −1 to 671 cm −1 in the presence of nanoparticles that increase the non-bridging oxygen, confirmed by the intensity change of the TeO 3 peak at 752 cm −1 . A new peak around 461 cm −1 is also observed which is attributed to the band characteristic of covalent Fe–O linkages. A decrease in the Urbach energy as much as 0.122 eV and the optical energy band gap with the increase of Fe 3 O 4 concentration (0.5–1.0 mol%) is evidenced. Electronic polarizability of the glasses increases with increasing Fe 3 O 4 nanoparticles concentration up to 1 mol%. Interestingly, the polarizability tends to decrease with the further increase of Fe 3 O 4 concentration at 2 mol%. The role of magnetic nanoparticles in influencing the structural and optical behavior are examined and understood. - Highlights: ► Incorporation of natural Fe 3 O 4 nanoparticles into the zinc–tellurite glass. ► Influence of magnetic nanoparticles in modifying structure and optical properties. ► Enhancement of refraction index and change in electronic polarizability

  2. Hydrothermal Synthesis of Fe3O4 Nanoparticles and Flame Resistance Magnetic Poly styrene Nanocomposite

    Directory of Open Access Journals (Sweden)

    Kambiz Hedayati

    2017-01-01

    Full Text Available Fe3O4 nanostructures were synthesized via a facile hydrothermal reaction. The effect of various surfactants such as cationic and anionic on the morphology of the product was investigated. Magnetic nanoparticles were added to poly styrene for preparation of magnetic nanocomposite. Nanostructures were then characterized using X-ray diffraction, scanning electron microscopy and Fourier transform infrared spectroscopy. The magnetic properties of the samples were also investigated using vibrating sample magnetometer. The magnesium ferrite nanoparticles exhibit super paramagnetic behaviour at room temperature, with a saturation magnetization of 66 emu/g and a coercivity less than 5 Oe. Distribution of the magnetic nanoparticles into poly styrene matrix increases the coercivity. Nanoparticles appropriately enhanced flame retardant property of the PS matrix. Nanoparticles act as barriers which decrease thermal transport and volatilization during decomposition of the polymer.

  3. Solvothermal synthesis and electrochemical performance of hollow LiFePO{sub 4} nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Zhenmiao [School of Chemistry and Chemical Engineering, Central South University, Changsha 410083 (China); Pang, Wei Kong [Institute for Superconducting and Electronic Materials, University of Wollongong, Wollongong, NSW 2522 (Australia); Australian Nuclear Science and Technology Organization, Locked Bag 2001, Kirrawee DC, NSW 2232 (Australia); Tang, Xincun, E-mail: tangxincun@163.com [School of Chemistry and Chemical Engineering, Central South University, Changsha 410083 (China); Jia, Dianzeng; Huang, Yudai [Institute of Applied Chemistry, Xinjiang University, Urumqi 840046 (China); Guo, Zaiping [Institute for Superconducting and Electronic Materials, University of Wollongong, Wollongong, NSW 2522 (Australia)

    2015-08-15

    Highlights: • Hollow LiFePO{sub 4} nanoparticles were successfully synthesized via solvothermal method. • The shorter b lattice parameter allows the shorter diffusion path of lithium ion. • Hollow LiFePO{sub 4} nanoparticles show better rate capability than solid LiFePO{sub 4}. - Abstract: Hollow LiFePO{sub 4} nanoparticles were synthesized via a solvothermal technique, using ammonium tartrate as additive and carbon source, and ethylene glycol/water as solvent. The as-prepared samples were characterized by X-ray diffraction, Fourier-transform infrared spectroscopy, Raman spectroscopy, scanning and transmission electron microscopies, and Brunauer–Emmett–Teller specific surface area measurements. The electrochemical properties of the LiFePO{sub 4} cathode were examined in coin-type cell configuration and the cathode exhibited excellent rate capability (i.e., discharge capacity of 120.9 mA h g{sup −1} at 10 C) and cycling performance (i.e., >98% of capacity retention rate after 50 cycles). It is believed that the enhanced performance is correlated to the hollow structure, small crystallite and particle sizes, and relatively shorter lattice parameter b.

  4. Antimicrobial Activities of Silver Nanoparticles Synthesized by Using Water Extract of Arnicae anthodium.

    Science.gov (United States)

    Dobrucka, Renata; Długaszewska, Jolanta

    2015-06-01

    Green synthesis of nanoparticles has gained significant importance in recent years and has become the one of the most preferred methods. Also, green synthesis of nanoparticles is valuable branch of nanotechnology. Plant extracts are eco-friendly and can be an economic option for synthesis of nanoparticles. This study presents method the synthesis of silver nanoparticles using water extract of Arnicae anthodium. Formation of silver nanoparticles was confirmed by UV-visble spectroscopy, Fourier transform infrared spectroscopy and total reflection X-ray fluorescence analysis. The morphology of the synthesized silver nanoparticles was verified by SEM-EDS. The obtained silver nanoparticles were used to study their antimicrobial activity.

  5. Studies on the Fe3+ Doping Effect on Structural, Optical and Catalytic Properties of Hydrothermally Synthesized TiO2 Photocatalyst

    Energy Technology Data Exchange (ETDEWEB)

    Kamble, Ravi [Department of Physics, Jaysingpur College, Jaysingpur-416101, India; Sabale, Sandip [P.G. Department of Chemistry, Jaysingpur College, Jaysingpur-416101, Maharashtra, India; Chikode, Prashant [Department of Physics, Jaysingpur College, Jaysingpur-416101, India; Puri, Vijaya [Department of Physics, Shivaji University, Kolhapur-416004, India; Yu, Xiao-Ying [Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory (PNNL), Richland, WA 99352, United States; Mahajan, Smita [Department of Physics, Jaysingpur College, Jaysingpur-416101, India

    2017-08-01

    Pure TiO2 and Fe3+-TiO2 nanoparticles have been prepared by simple hydrothermal method with different Fe3+ concentrations. The synthesized nanoparticles are analysed to determine its structural, optical, morphological and compositional properties using X-ray diffraction, Raman, UV-DRS, photoluminescence, Mossbauer, XPS, TEM and SEM/EDS. The EDS micrograph confirms the existence of Fe3+ atoms in the TiO2 matrix with 0.85, 1.52 and 1.87 weight percent. The crystallite size and band gap decrease with increase in Fe3+concentration. The average particle size obtained from TEM is 7-11 nm which is in good agreement with XRD results. Raman bands at 640 cm-1, 517 cm-1 and 398 cm-1 further confirm pure phase anatase in all samples. XPS shows the proper substitutions of few sites of Ti4+ ions by Fe3+ ions in the TiO2 host lattice. The intensity of PL spectra for Fe3+-TiO2 shows a gradual decrease in the peak intensity with increasing Fe3+ concentration in TiO2, and it indicates lower recombination rate as Fe3+ ions increases. These nanoparticles are further studied for its photocatalytic activities using malachite green dye under UV light, visible light and sunlight.

  6. Supercapacitors studies on BiPO4 nanoparticles synthesized via a simple microwave approach

    Directory of Open Access Journals (Sweden)

    S. Vadivel

    2017-07-01

    Full Text Available BiPO4 nanomaterial was synthesized using EDTA (ethylene diamine tetra acetic acid as the surfactant via a simple microwave method. The structure and morphology of BiPO4 were systematically characterized by X-ray diffraction (XRD, Fourier-transform infrared spectroscopy (FT-IR, and scanning electron microscopy (FE-SEM studies. The obtained BiPO4 nanoparticles were, on average, 150–300 nm. The electrochemical results showed that the specific capacitance of BiPO4 obtained using the microwave route was up to 104 Fg−1 at a current density of 1 Ag−1 with a large potential window of 1.7 V. The material showed excellent cycling stability (92% capacitance retention after 500 cycles at a current density of 1 Ag−1.

  7. A study on the effect of chemically synthesized magnetite nanoparticles on earthworm: Eudrilus eugeniae

    Science.gov (United States)

    Samrot, Antony V.; Justin, C.; Padmanaban, S.; Burman, Ujjala

    2017-02-01

    Most look into the benefits of the nanoparticles, but keeping aside the benefits; this study focuses on the impacts of nanoparticles on living systems. Improper disposal of nanoparticles into the environment is a subject of pollution or nano-pollution which in turn affects the flora and fauna in the ecosystem, particularly soil ecosystem. Thus, this study was done to understand the impacts of chemically synthesized magnetite nanoparticles on earthworm— Eudrilus eugeniae, a soil-dependent organism which acquires food and nutrition from decaying matters. The chemically synthesized magnetite nanoparticles were characterized by UV-visible spectrophotometry, Fourier transform infrared spectroscopy and field emission scanning electron microscopy. Earthworms were allowed to interact with different concentrations of synthesized nanoparticles and the effect of the nanoparticles was analysed by studying the phenotypic changes followed by histology and inductively coupled plasma optical emission spectrometry analyses.

  8. Green synthesis of soya bean sprouts-mediated superparamagnetic Fe3O4 nanoparticles

    International Nuclear Information System (INIS)

    Cai Yan; Shen Yuhua; Xie Anjian; Li Shikuo; Wang Xiufang

    2010-01-01

    Superparamagnetic Fe 3 O 4 nanoparticles were first synthesized via soya bean sprouts (SBS) templates under ambient temperature and normal atmosphere. The reaction process was simple, eco-friendly, and convenient to handle. The morphology and crystalline phase of the nanoparticles were determined from scanning electron microscopy (SEM), transmission electron microscopy (TEM), selected area electron diffraction (SAED), and X-ray diffraction (XRD) spectra. The effect of SBS template on the formation of Fe 3 O 4 nanoparticles was investigated using X-ray photoemission spectroscopy (XPS) and Fourier-transform infrared spectroscopy (FT-IR). The results indicate that spherical Fe 3 O 4 nanoparticles with an average diameter of 8 nm simultaneously formed on the epidermal surface and the interior stem wall of SBS. The SBS are responsible for size and morphology control during the whole formation of Fe 3 O 4 nanoparticles. In addition, the superconducting quantum interference device (SQUID) results indicate the products are superparamagnetic at room temperature, with blocking temperature (T B ) of 150 K and saturation magnetization of 37.1 emu/g.

  9. Green synthesis of soya bean sprouts-mediated superparamagnetic Fe 3O 4 nanoparticles

    Science.gov (United States)

    Cai, Yan; Shen, Yuhua; Xie, Anjian; Li, Shikuo; Wang, Xiufang

    2010-10-01

    Superparamagnetic Fe 3O 4 nanoparticles were first synthesized via soya bean sprouts (SBS) templates under ambient temperature and normal atmosphere. The reaction process was simple, eco-friendly, and convenient to handle. The morphology and crystalline phase of the nanoparticles were determined from scanning electron microscopy (SEM), transmission electron microscopy (TEM), selected area electron diffraction (SAED), and X-ray diffraction (XRD) spectra. The effect of SBS template on the formation of Fe 3O 4 nanoparticles was investigated using X-ray photoemission spectroscopy (XPS) and Fourier-transform infrared spectroscopy (FT-IR). The results indicate that spherical Fe 3O 4 nanoparticles with an average diameter of 8 nm simultaneously formed on the epidermal surface and the interior stem wall of SBS. The SBS are responsible for size and morphology control during the whole formation of Fe 3O 4 nanoparticles. In addition, the superconducting quantum interference device (SQUID) results indicate the products are superparamagnetic at room temperature, with blocking temperature ( TB) of 150 K and saturation magnetization of 37.1 emu/g.

  10. Dechlorination of 2,4-dichlorophenoxyacetic acid by sodium carboxymethyl cellulose-stabilized Pd/Fe nanoparticles

    International Nuclear Information System (INIS)

    Zhou, Hongyi; Han, Jian; Baig, Shams Ali; Xu, Xinhua

    2011-01-01

    Highlights: ► CMC-stabilized Pd/Fe nanoparticles were synthesized and used for 2,4-D removal. ► Particle stability, ζ-potential and IEP of non- and stabilized Pd/Fe were compared. ► Dechlorination of 2,4-D by different Pd/Fe systems was investigated. ► The reaction mechanism has been discussed and presented in the article. ► Effects of CMC/Fe mass ratio and pH were also investigated. - Abstract: This paper describes the synthesis of sodium carboxymethyl cellulose (CMC)-stabilized Pd/Fe nanoparticles and their applications to the dechlorination of 2,4-dichlorophenoxyacetic acid (2,4-D) under controlled laboratorial conditions. For this purpose batch mode experiments were conducted to understand the effects of CMC on the surface characteristics of Pd/Fe nanoparticles, optimum removal of 2,4-D and other surface interactions mechanism. Our experimental results demonstrated considerable enhancements in particle stability and chemical reactivity with the addition of CMC to Pd/Fe nanoparticles. Transmission electron microscopy (TEM) analysis indicated that CMC-stabilized Pd/Fe nanoparticles were well dispersed, and nanoparticles remained in suspension for days compared to non-stabilized Pd/Fe nanoparticles precipitated within minutes. The isoelectric point (IEP) of the nanoparticles shifted from pH 6.5 to 2.5, suggesting that CMC-stabilized Pd/Fe nanoparticles were negatively charged over a wider pH range. Our batch experiments demonstrated that CMC-stabilized Pd/Fe nanoparticles (0.6 g Fe L −1 ) were able to remove much higher levels of 2,4-D with only one intermediate 2-chlorophenoxyacetic acid (2-CPA) and the final organic product phenoxyacetic acid (PA), than non-stabilized Pd/Fe nanoparticles or microsized Pd/Fe particles. The removal percentage of 2,4-D increased from 10% to nearly 100% as the reaction pH decreased from 11.5 to 2.5. The optimal CMC/Fe mass ratio for the dechlorination of 2,4-D was determined to be 5/1, and the removal of 2,4-D was

  11. Dechlorination of 2,4-dichlorophenoxyacetic acid by sodium carboxymethyl cellulose-stabilized Pd/Fe nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Hongyi, E-mail: zhouhy@zjut.edu.cn [College of Biological and Environmental Engineering, Zhejiang University of Technology, Hangzhou 310032 (China); Han, Jian [College of Biological and Environmental Engineering, Zhejiang University of Technology, Hangzhou 310032 (China); Baig, Shams Ali; Xu, Xinhua [Department of Environmental Engineering, Zhejiang University, Hangzhou 310027 (China)

    2011-12-30

    Highlights: Black-Right-Pointing-Pointer CMC-stabilized Pd/Fe nanoparticles were synthesized and used for 2,4-D removal. Black-Right-Pointing-Pointer Particle stability, {zeta}-potential and IEP of non- and stabilized Pd/Fe were compared. Black-Right-Pointing-Pointer Dechlorination of 2,4-D by different Pd/Fe systems was investigated. Black-Right-Pointing-Pointer The reaction mechanism has been discussed and presented in the article. Black-Right-Pointing-Pointer Effects of CMC/Fe mass ratio and pH were also investigated. - Abstract: This paper describes the synthesis of sodium carboxymethyl cellulose (CMC)-stabilized Pd/Fe nanoparticles and their applications to the dechlorination of 2,4-dichlorophenoxyacetic acid (2,4-D) under controlled laboratorial conditions. For this purpose batch mode experiments were conducted to understand the effects of CMC on the surface characteristics of Pd/Fe nanoparticles, optimum removal of 2,4-D and other surface interactions mechanism. Our experimental results demonstrated considerable enhancements in particle stability and chemical reactivity with the addition of CMC to Pd/Fe nanoparticles. Transmission electron microscopy (TEM) analysis indicated that CMC-stabilized Pd/Fe nanoparticles were well dispersed, and nanoparticles remained in suspension for days compared to non-stabilized Pd/Fe nanoparticles precipitated within minutes. The isoelectric point (IEP) of the nanoparticles shifted from pH 6.5 to 2.5, suggesting that CMC-stabilized Pd/Fe nanoparticles were negatively charged over a wider pH range. Our batch experiments demonstrated that CMC-stabilized Pd/Fe nanoparticles (0.6 g Fe L{sup -1}) were able to remove much higher levels of 2,4-D with only one intermediate 2-chlorophenoxyacetic acid (2-CPA) and the final organic product phenoxyacetic acid (PA), than non-stabilized Pd/Fe nanoparticles or microsized Pd/Fe particles. The removal percentage of 2,4-D increased from 10% to nearly 100% as the reaction pH decreased from 11

  12. Novel solid-state synthesis of α-Fe and Fe3O4 nanoparticles embedded in a MgO matrix

    Science.gov (United States)

    Schneeweiss, O.; Zboril, R.; Pizurova, N.; Mashlan, M.; Petrovsky, E.; Tucek, J.

    2006-01-01

    Thermally induced reduction of amorphous Fe2O3 nanopowder (2-3 nm) with nanocrystalline Mg (~20 nm) under a hydrogen atmosphere is presented as a novel route to obtain α-Fe and Fe3O4 magnetic nanoparticles dispersed in a MgO matrix. The phase composition, structural and magnetic properties, size and morphology of the nanoparticles were monitored by x-ray diffraction, 57Fe Mössbauer spectroscopy at temperatures of 24-300 K, transmission electron microscopy and magnetic measurements. Spherical magnetite nanoparticles prepared at a reaction temperature of 300 °C revealed a well-defined structure, with a ratio of tetrahedral to octahedral Fe sites of 1/2 being common for the bulk material. A narrow particle size distribution (20-30 nm) and high saturation magnetization (95 ± 5 A m2 kg-1) predispose the magnetite nanoparticles to various applications, including magnetic separation processes. The Verwey transition of Fe3O4 nanocrystals was found to be decreased to about 80 K. The deeper reduction of amorphous ferric oxide at 600 °C allows α-Fe (40-50 nm) nanoparticles to be synthesized with a coercive force of about 30 mT. They have a saturation magnetization 2.2 times higher than that of synthesized magnetite nanoparticles, which corresponds well with the ratio usually found for the pure bulk phases. The magnetic properties of α-Fe nanocrystals combined with the high chemical and thermal stability of the MgO matrix makes the prepared nanocomposite useful for various magnetic applications.

  13. Fe Core–Carbon Shell Nanoparticles as Advanced MRI Contrast Enhancer

    Directory of Open Access Journals (Sweden)

    Rakesh P. Chaudhary

    2017-10-01

    Full Text Available The aim of this study is to fabricate a hybrid composite of iron (Fe core–carbon (C shell nanoparticles with enhanced magnetic properties for contrast enhancement in magnetic resonance imaging (MRI. These new classes of magnetic core–shell nanoparticles are synthesized using a one-step top–down approach through the electric plasma discharge generated in the cavitation field in organic solvents by an ultrasonic horn. Transmission electron microscopy (TEM observations revealed the core–shell nanoparticles with 10–85 nm in diameter with excellent dispersibility in water without any agglomeration. TEM showed the structural confirmation of Fe nanoparticles with body centered cubic (bcc crystal structure. Magnetic multi-functional hybrid composites of Fe core–C shell nanoparticles were then evaluated as negative MRI contrast agents, displaying remarkably high transverse relaxivity (r2 of 70 mM−1·S−1 at 7 T. This simple one-step synthesis procedure is highly versatile and produces desired nanoparticles with high efficacy as MRI contrast agents and potential utility in other biomedical applications.

  14. TEA controllable preparation of magnetite nanoparticles (Fe3O4 NPs) with excellent magnetic properties

    Science.gov (United States)

    Han, Chengliang; Zhu, Dejie; Wu, Hanzhao; Li, Yao; Cheng, Lu; Hu, Kunhong

    2016-06-01

    A fast and controllable synthesis method for superparamagnetic magnetite nanoparticles (Fe3O4 NPs) was developed in Fe(III)-triethanolamine (TEA) solution. The phase structure, morphology and particle size of the as-synthesized samples were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The results showed that the magnetic particles were pure Fe3O4 with mean sizes of approximately 10 nm. The used TEA has key effects on the formation of well dispersing Fe3O4 NPs. Vibrating sample magnetometer (VSM) result indicated that the as-obtained Fe3O4 NPs exhibited superparamagnetic behavior and the saturation magnetization (Ms) was about 70 emu/g, which had potential applications in magnetic science and technology.

  15. Magnetic and structural characterizations on nanoparticles of FePt, FeRh and their composites

    International Nuclear Information System (INIS)

    Ko, Hnin Yu Yu; Suzuki, Takao; Nam, Nguyen T.; Phuoc, Nguyen N.; Cao Jiangwei; Hirotsu, Yoshihiko

    2008-01-01

    The various compositions of FePt and FeRh nanoparticles, and their composite particles have been fabricated by the solution-phase chemical method and their magnetic properties characterized. High-resolution transmission electron microscopic observations indicate that mono-dispersed FeRh and FePt/FeRh nanoparticles are fabricated with the average size of 3-5 nm. However, larger size particles are distributed in the annealed state. From X-ray diffraction results, the as-deposited FeRh nanoparticles reveal a chemically disordered fcc structure which can be transformed into CsCl-type structure through thermal annealing. Similarly, the annealed FePt nanoparticles show the L1 0 -phase fct structure although the fcc structure is apparent in the as-deposited state. It is also found that the first time in the exchange bias effect in the composite of ferromagnetic (FePt) and anti-ferromagnetic (FeRh) nanoparticles; result in a shift of the hysteresis loop after field cooling process

  16. Synthesis and characterization of polyethylene glycol (PEG) coated Fe3O4 nanoparticles by chemical co-precipitation method for biomedical applications.

    Science.gov (United States)

    Anbarasu, M; Anandan, M; Chinnasamy, E; Gopinath, V; Balamurugan, K

    2015-01-25

    Polyethylene glycol (PEG) coated Fe3O4 nanoparticles were synthesized by chemical co-precipitation method. With polyethylene glycol (PEG) as a stabilizer and dispersant. The X-ray diffraction and selected area electron diffraction (SAED) results show that the cubic inverse spinel structure of pure phase polycrystalline Fe3O4 was obtained. The scanning electron microscopy (SEM) and field emission transmission electron microscopy (FE-TEM) results exhibited that the resulted Fe3O4 nanoparticles were roughly spherical in shape with narrow size distribution and homogenous shape. Fourier transform infrared spectroscopy (FT-IR) results suggested that PEG indicated with Fe3O4 via its carbonyl groups. Results of vibrating sample magnetometer (VSM) indicated that the prepared Fe3O4 nanoparticles exhibit superparamagnetic behavior and high saturation magnetization at room temperature. Such Fe3O4 nanoparticles with favorable size and tunable magnetic properties are promising biomedical applications. Copyright © 2014. Published by Elsevier B.V.

  17. Synthesis, characterization and photocatalytic activity of Fe2O3-TiO2 nanoparticles and nanocomposites

    Directory of Open Access Journals (Sweden)

    M. Ahmadi Golsefidi

    2016-01-01

    Full Text Available In this pepper Fe2O3 nanoparticles were synthesized via a fast microwave method. Then Fe2O3-TiO2 nanocomposites were synthesized by a sonochemical-assisted method. The prepared products were characterized by X-ray diffraction pattern, scanning electron microscopy and Fourier transform infrared spectroscopy. The photocatalytic behaviour of Fe2O3-TiO2 nanocomposites was evaluated using the degradation of Rhodamine B under ultra violet irradiation. The results show that nanocomposites have applicable magnetic and photocatalytic performance.

  18. Ultrasonic-assisted in situ synthesis and characterization of superparamagnetic Fe{sub 3}O{sub 4} nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Feng Jie [College of Materials Science and Engineering, Sichuan University, Chengdu 610064 (China); Mao Jian, E-mail: maojianemail@163.com [College of Materials Science and Engineering, Sichuan University, Chengdu 610064 (China); Wen Xiaogang; Tu Mingjing [College of Materials Science and Engineering, Sichuan University, Chengdu 610064 (China)

    2011-09-15

    Highlights: > Fe{sup 3+} as the only Fe source for preparing Fe{sub 3}O{sub 4} nanoparticles through in situ cover and sonication method. > Surface modification enables the reduction of the grain size of Fe{sub 3}O{sub 4}. > Increasing temperature reduces grain size of Fe{sub 3}O{sub 4} until it exceeds 80 deg. C. > Increasing pH values reduces grain size of Fe{sub 3}O{sub 4} until it exceeds 11. > Saturation magnetizations depend on the grain size of Fe{sub 3}O{sub 4} nanoparticles. - Abstract: Superparamagnetic Fe{sub 3}O{sub 4} nanoparticles were synthesized via a modified coprecipitation method, and were characterized with X-ray diffraction (XRD), vibrating sample magnetometer (VSM), Zeta potential and FT-IR, respectively. The influences of different kinds of surfactants (sodium dodecyl benzene sulfonate, polyethyleneglycol, oleic acid and dextran), temperatures and pH values on the grain size and properties were also investigated. In this method, Fe{sup 3+} was used as the only Fe source and partially reduced to Fe{sup 2+} by the reducing agent with precise content. The following reaction between Fe{sup 3+}, Fe{sup 2+} and hydroxide radical brought pure Fe{sub 3}O{sub 4} nanoparticles. The tiny fresh nanoparticles were coated in situ with surfactant under the action of sonication. Comparing with uncoated sample, the mean grain size and saturation magnetization of coated Fe{sub 3}O{sub 4} nanoparticles decrease from 18.4 nm to 5.9-9.0 nm, and from 63.89 emu g{sup -1} to 52-58 emu g{sup -1} respectively. When oleic was used as the surfactant, the mean grain size of Fe{sub 3}O{sub 4} nanoparticles firstly decreases with the increase of reaction temperature, but when the temperature is exceed to 80 deg. C, the continuous increase of temperature resulted in larger nanoparticles. the grain size decreases gradually with the increasing of pH values, and it remains unchanged when the PH value is up to 11. The saturation magnetization of as-prepared Fe{sub 3}O{sub 4

  19. Synthesis and characterization of FePt/Au core-shell nanoparticles

    International Nuclear Information System (INIS)

    Presa, P. de la; Multigner, M.; Morales, M.P.; Rueda, T.; Fernandez-Pinel, E.; Hernando, A.

    2007-01-01

    In this work, the structural and magnetic properties of the gold-coated FePt nanoparticles synthesized from high-temperature solution phase are presented. The amount of gold was optimized to obtain most of the FePt particles coated. The particle diameter increases from 4 to 10 nm as observed by TEM. The magnetic properties are largely affected by the coating. At low temperature, the coercive field Hc of the coated nanoparticles decreases about three times respect to the uncoated and the blocking temperature reduces to the half. The changes of the magnetic behavior are discussed in terms of the effect of the gold atoms at the FePt core surface

  20. Recent Progress in Syntheses and Applications of Dumbbell-like Nanoparticles**

    OpenAIRE

    Wang, Chao; Xu, Chenjie; Zeng, Hao; Sun, Shouheng

    2009-01-01

    This paper reviews the recent research progress in syntheses and applications of dumbbell-like nanoparticles. It first describes the general synthesis of dumbbell-like nanoparticles containing noble metal and magnetic NPs/or quantum dots. It then outlines the interesting optical and magnetic properties found in these dumbbell nanoparticles. The review further highlights several exciting application potentials of these nanoparticles in catalysis and biomedicine.

  1. Debromination of polybrominated diphenyl ethers by Ni/Fe bimetallic nanoparticles: Influencing factors, kinetics, and mechanism

    International Nuclear Information System (INIS)

    Fang Zhanqiang; Qiu Xinhong; Chen Jinhong; Qiu Xiuqi

    2011-01-01

    Polybrominated diphenyl ethers have been identified as a new class of organic pollutants with ecological risk due to their toxicity, bioaccumulation, and global distribution. Proper remediation technologies are needed to remove them from the environment. In this paper, Ni/Fe bimetallic nanoparticles were synthesized by chemical deposition and used to degrade decabromodiphenyl ether (BDE209). The characteristics of Ni/Fe nanoparticles were analyzed by transmission electron microscopy, X-ray diffractometry, X-ray photoelectron spectroscopy, and Brunnaer-Emmett-Teller surface area analysis. Ni/Fe bimetallic nanoparticles with diameters in the order of 20-50 nm could effectively degrade BDE209 in the solvent (tetrahydrofuran/water). Influence factors, such as Ni/Fe nanoparticle dosage, initial BDE209 concentration, and Ni loading, on the removal of BDE209 were studied. The results indicated that the degradation of BDE209 followed pseudo-first-order kinetics, and the degradation rate of BDE209 increased with increasing the amount of nano Ni/Fe particles, Ni/Fe ratio, and decreasing the initial concentration of BDE209. Through analyzed the mass balance of the BDE209 removal, degradation was the main process of BDE209 removal. The mechanism of debromination was deduced by analyzing the reaction products using gas chromatography-mass spectrometry, the bromide ion in the solution and varying the solvent conditions. Stepwise hydrogen reduction is the main process of debromination, and the hydrion play an important role in the reaction. Moreover, the experiment of long term performance and leaching of Ni were also carried out to test the stability and durability of Ni/Fe nanoparticles in BDE209 degradation.

  2. Preparation of Multifunctional Fe@Au Core-Shell Nanoparticles with Surface Grafting as a Potential Treatment for Magnetic Hyperthermia

    Directory of Open Access Journals (Sweden)

    Ren-Jei Chung

    2014-01-01

    Full Text Available Iron core gold shell nanoparticles grafted with Methotrexate (MTX and indocyanine green (ICG were synthesized for the first time in this study, and preliminarily evaluated for their potential in magnetic hyperthermia treatment. The core-shell Fe@Au nanoparticles were prepared via the microemulsion process and then grafted with MTX and ICG using hydrolyzed poly(styrene-alt-maleic acid (PSMA to obtain core-shell Fe@Au-PSMA-ICG/MTX nanoparticles. MTX is an anti-cancer therapeutic, and ICG is a fluorescent dye. XRD, TEM, FTIR and UV-Vis spectrometry were performed to characterize the nanoparticles. The data indicated that the average size of the nanoparticles was 6.4 ± 09 nm and that the Au coating protected the Fe core from oxidation. MTX and ICG were successfully grafted onto the surface of the nanoparticles. Under exposure to high frequency induction waves, the superparamagnetic nanoparticles elevated the temperature of a solution in a few minutes, which suggested the potential for an application in magnetic hyperthermia treatment. The in vitro studies verified that the nanoparticles were biocompatible; nonetheless, the Fe@Au-PSMA-ICG/MTX nanoparticles killed cancer cells (Hep-G2 via the magnetic hyperthermia mechanism and the release of MTX.

  3. Preparation of Multifunctional Fe@Au Core-Shell Nanoparticles with Surface Grafting as a Potential Treatment for Magnetic Hyperthermia.

    Science.gov (United States)

    Chung, Ren-Jei; Shih, Hui-Ting

    2014-01-24

    Iron core gold shell nanoparticles grafted with Methotrexate (MTX) and indocyanine green (ICG) were synthesized for the first time in this study, and preliminarily evaluated for their potential in magnetic hyperthermia treatment. The core-shell Fe@Au nanoparticles were prepared via the microemulsion process and then grafted with MTX and ICG using hydrolyzed poly(styrene-alt-maleic acid) (PSMA) to obtain core-shell Fe@Au-PSMA-ICG/MTX nanoparticles. MTX is an anti-cancer therapeutic, and ICG is a fluorescent dye. XRD, TEM, FTIR and UV-Vis spectrometry were performed to characterize the nanoparticles. The data indicated that the average size of the nanoparticles was 6.4 ± 09 nm and that the Au coating protected the Fe core from oxidation. MTX and ICG were successfully grafted onto the surface of the nanoparticles. Under exposure to high frequency induction waves, the superparamagnetic nanoparticles elevated the temperature of a solution in a few minutes, which suggested the potential for an application in magnetic hyperthermia treatment. The in vitro studies verified that the nanoparticles were biocompatible; nonetheless, the Fe@Au-PSMA-ICG/MTX nanoparticles killed cancer cells (Hep-G2) via the magnetic hyperthermia mechanism and the release of MTX.

  4. Ferromagnetic Behaviors in Fe-Doped NiO Nanofibers Synthesized by Electrospinning Method

    Directory of Open Access Journals (Sweden)

    Yi-Dong Luo

    2013-01-01

    Full Text Available Ni1−xFexO nanofibers with different Fe doping concentration have been synthesized by electrospinning method. An analysis of the phase composition and microstructure shows that Fe doping has no influence on the crystal structure and morphology of NiO nanofibers, which reveals that the doped Fe ions have been incorporated into the NiO host lattice. Pure NiO without Fe doping is antiferromagnetic, yet all the Fe-doped NiO nanofiber samples show obvious room-temperature ferromagnetic properties. The saturation magnetization of the nanofibers can be enhanced with increasing Fe doping concentration, which can be ascribed to the double exchange mechanism through the doped Fe ions and free charge carriers. In addition, it was found that the diameter of nanofibers has significant impact on the ferromagnetic properties, which was discussed in detail.

  5. Synthesis and magnetic properties of single-crystalline BaFe12O19 nanoparticles

    International Nuclear Information System (INIS)

    Yu Jiangying; Tang Shaolong; Zhai Lin; Shi Yangguang; Du Youwei

    2009-01-01

    Rod-like and platelet-like nanoparticles of simple-crystalline barium hexaferrite (BaFe 12 O 19 ) have been synthesized by the molten salt method. Both particle size and morphology change with the reaction temperature and time. The easy magnetization direction (0 0 l) of the BaFe 12 O 19 nanoparticles has been observed directly by performing X-ray diffraction on powders aligned at 0.5 T magnetic field. The magnetic properties of the BaFe 12 O 19 magnet were investigated with various sintering temperatures. The maximum values of saturation magnetization (σ s =65.8 emu/g), remanent magnetization (σ r =56 emu/g) and coercivity field (H ic =5251 Oe) of the aligned samples occurred at the sintering temperatures of 1100 deg. C. These results indicate that BaFe 12 O 19 nanoparticles synthesized by the molten salt method should enable detailed investigation of the size-dependent evolution of magnetism, microwave absorption, and realization of a nanodevice of magnetic media.

  6. Comparative study of synthesized silver and gold nanoparticles ...

    Indian Academy of Sciences (India)

    The present investigation aimed at comparing the synthesis, characterization and in vitro anticancer ... Bauhinia tomentosa Linn; silver nanoparticles; gold nanoparticles; A-549; HEp-2; MCF-7. 1. Introduction ..... Methods 65 55. [33] Singh A K ...

  7. Ultra-low Pt decorated PdFe Alloy Nanoparticles for Formic Acid Electro-oxidation

    International Nuclear Information System (INIS)

    Zhou, Yawei; Du, Chunyu; Han, Guokang; Gao, Yunzhi; Yin, Geping

    2016-01-01

    Highlights: • A cost-efficient way is used to prepare transition-noble metal alloy nanoparticles. • The Pd 50 Fe 50 /C catalyst shows excellent activity for formic acid oxidation (FAO). • Much activity enhancement of FAO is acquired by ultra-low Pt decorated Pd 50 Fe 50 . • A synergistic mechanism between Pt clusters and PdFe is proposed during the FAO. - Abstract: Palladium (Pd), has demonstrated promising electro-catalytic activity for formic acid oxidation, but suffers from extremely low abundance. Recently alloying with a transition metal has been considered as an effective approach to reducing the loading of Pd and enhancing the activity of Pd-based catalysts simultaneously. Herein, carbon supported PdFe nanoparticles (NPs) are synthesized at room temperature by using sodium borohydride as reducing agent and potassium ferrocyanide as Fe precursor. The Pd 50 Fe 50 alloy sample annealed at 900 °C for 1 h shows the best catalytic activity among Pd x Fe 1-x (x = 0.2, 0.4, 0.5, 0.6, and 0.8) towards formic acid oxidation. To further improve both catalytic activity and stability, the ultra-low Pt (0.09 wt %) decorated Pd 50 Fe 50 NPs (PtPd/PdFe) are prepared via the galvanic replacement reaction. Compared with Pd 50 Fe 50 /C, the PtPd/PdFe/C Exhibits 1.52 times higher catalytic activity and lower onset potential (−0.12 V). The significant enhancements of formic acid oxidation can be attributed to the accelerated dehydrogenation reaction of formic acid by Pt atomic clusters. Moreover, the PtPd/PdFe/C also demonstrates better tolerance to poisons during formic acid oxidation.

  8. ZnFe2O4 Containing Nanoparticles: Synthesis and Magnetic Properties

    Directory of Open Access Journals (Sweden)

    Zālīte Ilmārs

    2017-05-01

    Full Text Available Solid solutions of Co1−xZnxFe2O4 and Ni1−xZnxFe2O4 (0 < x < 1 nanoparticles were synthesized by sol-gel self-propagating combustion method. The obtained single cubic phase product has a specific surface area 25 m2∙g−1 to 33 m2∙g−1 and crystallite size 25 nm to 40 nm. Lattice parameters change linearly from 8.371 A (CoFe2O4 and 8.337 A (NiFe2O4 to 8.431 A (ZnFe2O4. The saturation magnetization (Ms changes non-linearly from 60.8 emu∙g−1 (CoFe2O4, respectively, from 35.6 emu∙g−1 (NiFe2O4 to 3.3 emu∙g−1 (ZnFe2O4 reaching maximal value 76.1 emu∙g−1 for Co0.8Zn0.2Fe2O4 and 64.9 emu∙g−1 – for Ni0.6Zn0.4Fe2O4.

  9. Fabrication and surface transformation of FePt nanoparticle monolayer

    International Nuclear Information System (INIS)

    Wang Ying; Ding Baojun; Li Hua; Zhang Xiaoyan; Cai Bingchu; Zhang Yafei

    2007-01-01

    The monolayer of FePt nanoparticles with the mean size of ∼4 nm was fabricated on a glass substrate by the Langmuir--Blodgett (LB) technology. The monolayer of FePt nanoparticles has a smooth surface and a high density structure as shown by the AFM image. The array structure of FePt nanoparticles on the surface of the film is clearly with a cubic symmetry in appropriate condition. Small-angle X-ray diffraction (SXRD) measurement of multilayer structure for the FePt nanoparticles has indicated that the superlattices consist of well-defined smooth layers. The transfer of nanoparticle layers onto a solid substrate surface was quite efficient for the first few layers, exhibiting a proportional increase of optical absorption in the UV-vis range. This results potentially opens up a new approach to the long-range ordered array of FePt nanoparticles capped by organic molecules on substrate and provide a promising thin film, which may exhibit the excellent ultra-high density magnetic recording properties

  10. Interparticle interactions of FePt core and Fe{sub 3}O{sub 4} shell in FePt/Fe{sub 3}O{sub 4} magnetic nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Akbari, Hossein, E-mail: Akbari.ph@iauardabil.ac.ir [Department of Physics, Ardabil Branch, Islamic Azad University, Ardabil (Iran, Islamic Republic of); Zeynali, Hossein [Department of Physics, Kashan Branch, Islamic Azad University, Kashan (Iran, Islamic Republic of); Bakhshayeshi, Ali [Department of Physics, Mashhad Branch, Islamic Azad University, Mashhad (Iran, Islamic Republic of)

    2016-02-22

    Monodisperse FePt nanoparticles were successfully synthesized using simple wet chemical method. Fe{sub 3}O{sub 4} was used as a magnetic shell around each FePt nanoparticles. In FePt/Fe{sub 3}O{sub 4} core/shell system, core thickness is 2 nm and shell thickness varies from zero to 2.5 nm. A theoretical model presented to calculate the shell thickness dependence of Coercivity. Presented model is compared with the results from Stoner–Wohlfarth model to interpret the shell thickness dependence of Coercivity in FePt/Fe{sub 3}O{sub 4} core/shell nanoparticles. There is a difference between the results from Stoner–Wohlfarth model and experimental data when the shell thickness increases. In the presented model, the effects of interparticle exchange and random magneto crystalline anisotropy are added to the previous models of magnetization reversal for core/shell nanostructures in order to achieve a better agreement with experimental data. For magnetic shells in FePt/Fe{sub 3}O{sub 4} core/shell, effective coupling between particles increases with increasing shell thickness which leads to Coercivity destruction for stronger couplings. According to the boundary conditions, in the harder regions with higher exchange stiffness, there is small variation in magnetization and so the magnetization modes become more localized. We discussed both localized and non-localized magnetization modes. For non-zero shell thickness, non-localized modes propagate in the soft phase which effects the quality of particle exchange interactions. - Highlights: • Monodisperse FePt nanoparticles were successfully synthesized using simple wet chemical method. • Fe{sub 3}O{sub 4} was used as a magnetic shell around each FePt nanoparticles. • A theoretical model presented to calculate the shell thickness dependence of Coercivity. • Magnetic shells increase effective coupling between particles with increasing shell thickness. • Magnetization modes are more localized in the regions with

  11. Kinetics of 2-chlorobiphenyl Reductive Dechlorination by Pd-fe0 Nanoparticles

    Directory of Open Access Journals (Sweden)

    Jiang Junrong

    2016-01-01

    Full Text Available Kinetics of 2-chlorobiphenyl (2-Cl BP catalytic reductive dechlorination by Pd-Fe0 nanoparticles were investigated. Experimental results showed that ultrafine bimetallic Pd-Fe0e nanoparticles were synthesized in the presence of 40 kHz ultrasound in order to enhance disparity and avoid agglomeration. The application of ultrasonic irradiation during the synthesis of Pd-Fe0 nanoparticles further accelerated the dechlorinated removal ratio of 2-Cl BP. Up to 95.0% of 2-Cl BP was removed after 300 min reaction with the following experimental conditions: initial 2-Cl BP concentration 10 mg L-1, Pd content 0.8 wt. %, bimetallic Pd-Fe0 nanoparticles prepared in the presence of ultrasound available dosage 7g L-1, initial pH value in aqueous solution 3.0, and reaction temperature 25°C. The catalytic reductive dechlorination of 2-Cl BP followed pseudo-first-order kinetics and the apparent pseudo-first-order kinetics constant was 0.0143 min-1.

  12. Comparison effects and electron spin resonance studies of α-Fe2O4 spinel type ferrite nanoparticles.

    Science.gov (United States)

    Bayrakdar, H; Yalçın, O; Cengiz, U; Özüm, S; Anigi, E; Topel, O

    2014-11-11

    α-Fe2O4 spinel type ferrite nanoparticles have been synthesized by cetyltrimethylammonium bromide (CTAB) and ethylenediaminetetraacetic acid (EDTA) assisted hydrothermal route by using NaOH solution. Electron spin resonance (ESR/EPR) measurements of α-Fe2O4 nanoparticles have been performed by a conventional x-band spectrometer at room temperature. The comparison effect of nanoparticles prepared by using CTAB and EDTA in different α-doping on the structural and morphological properties have been investigated in detail. The effect of EDTA-assisted synthesis for α-Fe2O4 nanoparticles are refined, and thus the spectroscopic g-factor are detected by using ESR signals. These samples can be considered as great benefits for magnetic recording media, electromagnetic and drug delivery applications. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Oxygen vacancy induced by La and Fe into ZnO nanoparticles to modify ferromagnetic ordering

    International Nuclear Information System (INIS)

    Verma, Kuldeep Chand; Kotnala, R.K.

    2016-01-01

    We reported long-range ferromagnetic interactions in La doped Zn 0.95 Fe 0.05 O nanoparticles that mediated through lattice defects or vacancies. Zn 0.92 Fe 0.05 La 0.03 O (ZFLaO53) nanoparticles were synthesized by a sol–gel process. X-ray fluorescence spectrum of ZFLaO53 detects the weight percentage of Zn, Fe, La and O. X-ray diffraction shows the hexagonal Wurtzite ZnO phase. The Rietveld refinement has been used to calculate the lattice parameters and the position of Zn, Fe, La and O atoms in the Wurtzite unit cell. The average size of ZFLaO53 nanoparticles is 99 nm. The agglomeration type product due to OH ions with La results into ZnO nanoparticles than nanorods that found in pure ZnO and Zn 0.95 Fe 0.05 O sample. The effect of doping concentration to induce Wurtzite ZnO structure and lattice defects has been analyzed by Raman active vibrational modes. Photoluminescence spectra show an abnormal emission in both UV and visible region, and a blue shift at near band edge is formed with doping. The room temperature magnetic measurement result into weak ferromagnetism but pure ZnO is diamagnetic. However, the temperature dependent magnetic measurement using zero-field and field cooling at dc magnetizing field 500 Oe induces long-range ferromagnetic ordering. It results into antiferromagnetic Neel temperature of ZFLaO53 at around 42 K. The magnetic hysteresis is also measured at 200, 100, 50 and 10 K measurement that indicate enhancement in ferromagnetism at low temperature. Overall, the La doping into Zn 0.95 Fe 0.05 O results into enhanced antiferromagnetic interaction as well as lattice defects/vacancies. The role of the oxygen vacancy as the dominant defects in doped ZnO must form Bound magnetic polarons has been described. - Graphical abstract: The long-range ferromagnetic order in Zn 0.92 Fe 0.05 La 0.03 O nanoparticles at low temperature measurements involves oxygen vacancy as the medium of magnetic interactions. - Highlights: • The La and Fe doping

  14. Synthesis, Characterizations of Superparamagnetic Fe3O4-Ag Hybrid Nanoparticles and Their Application for Highly Effective Bacteria Inactivation.

    Science.gov (United States)

    Tung, Le Minh; Cong, Nguyen Xuan; Huy, Le Thanh; Lan, Nguyen Thi; Phan, Vu Ngoc; Hoa, Nguyen Quang; Vinh, Le Khanh; Thinh, Nguyen Viet; Tai, Le Thanh; Ngo, Duc-The; Mølhave, Kristian; Huy, Tran Quang; Le, Anh-Tuan

    2016-06-01

    In recent years, outbreaks of infectious diseases caused by pathogenic micro-organisms pose a serious threat to public health. In this work, Fe3O4-Ag hybrid nanoparticles were synthesized by simple chemistry method and these prepared nanoparticles were used to investigate their antibacterial properties and mechanism against methicilline-resistant Staphylococcus aureus (MRSA) pathogen. The formation of dimer-like nanostructure of Fe3O4-Ag hybrid NPs was confirmed by X-ray diffraction and High-resolution Transmission Electron Microscopy. Our biological analysis revealed that the Fe3O4-Ag hybrid NPs showed more noticeable bactericidal activity than that of plain Fe3O4 NPs and Ag-NPs. We suggest that the enhancement in bactericidal activity of Fe3O4-Ag hybrid NPs might be likely from main factors such as: (i) enhanced surface area property of hybrid nanoparticles; (ii) the high catalytic activity of Ag-NPs with good dispersion and aggregation stability due to the iron oxide magnetic carrier, and (iii) large direct physical contacts between the bacterial cell membrane and the hybrid nanoparticles. The superparamagnetic hybrid nanoparticles of iron oxide magnetic nanoparticles decorated with silver nanoparticles can be a potential candidate to effectively treat infectious MRSA pathogen with recyclable capability, targeted bactericidal delivery and minimum release into environment.

  15. Structural and magnetic properties of sol-gel derived CaFe2O4 nanoparticles

    Science.gov (United States)

    Das, Arnab Kumar; Govindaraj, Ramanujan; Srinivasan, Ananthakrishnan

    2018-04-01

    Calcium ferrite nanoparticles with average crystallite size of ∼11 nm have been synthesized by sol-gel method by mixing calcium and ferric nitrates in stoichiometric ratio in the presence of ethylene glycol. As-synthesized nanoparticles were annealed at different temperatures and their structural and magnetic properties have been evaluated. X-ray diffraction studies showed that unlike most ferrites, as-synthesized cubic calcium ferrite showed a slow transformation to orthorhombic structure when annealed above 400 °C. Single phase orthorhombic CaFe2O4 was obtained upon annealing at 1100 °C. Divergence of zero field cooled and field cooled magnetization curves at low temperatures indicated superparamagnetic behavior in cubic calcium ferrite particles. Superparamagnetism persisted in cubic samples annealed up to 500 °C. As-synthesized nanoparticles heat treated at 1100 °C exhibited mixed characteristics of antiferromagnetic and paramagnetic grains with saturation magnetization of 0.4 emu/g whereas nanoparticles calcined at 400 °C exhibited superparamagnetic characteristics with saturation magnetization of 22.92 emu/g. An antiferromagnetic to paramagnetic transition was observed between 170 and 190 K in the sample annealed at 1100 °C, which was further confirmed by Mössbauer studies carried out at different temperatures across the transition.

  16. Sintering prevention and phase transformation of FePt nanoparticles

    International Nuclear Information System (INIS)

    Ding, Y.; Majetich, S.A.; Kim, J.; Barmak, K.; Rollins, H.; Sides, P.

    2004-01-01

    Two approaches attempted to overcome FePt nanoparticle sintering during the transformation to the high coercivity L1 0 phase, which currently limits the use of these nanoparticles in data storage media. High-pressure treatment of dilute nanoparticle solutions failed to prevent sintering due to surfactant decomposition above 360 deg. C. By pre-annealing nanoparticle monolayers to decompose the surfactant, and then coating with an immiscible SiO 2 matrix, sintering was prevented with annealing temperatures up to 700 deg. C

  17. Synthesis and characterization of Fe{sub 3}O{sub 4} nanoparticles coated with fucan polysaccharides

    Energy Technology Data Exchange (ETDEWEB)

    Silva, V.A.J.; Andrade, P.L. [Programa de Pós-Graduação em Ciências de Materiais, Centro de Ciências Exatas e da Natureza, Universidade Federal de Pernambuco, 50670-901 Recife-PE (Brazil); Laboratório de Imunopatologia Keizo Asami (LIKA), Universidade Federal de Pernambuco, 50670-901 Recife-PE (Brazil); Silva, M.P.C. [Laboratório de Imunopatologia Keizo Asami (LIKA), Universidade Federal de Pernambuco, 50670-901 Recife-PE (Brazil); Departamento de Bioquímica, Universidade Federal de Pernambuco, 50670-420 Recife-PE (Brazil); Bustamante D, A. [Laboratorio de Cerámicos y Nanomateriales, Facultad de Ciencias Físicas, Universidad Nacional Mayor de San Marcos, Ap. Postal 14-0149 Lima (Peru); De Los Santos Valladares, Luis [Laboratório de Imunopatologia Keizo Asami (LIKA), Universidade Federal de Pernambuco, 50670-901 Recife-PE (Brazil); Cavendish Laboratory, University of Cambridge, J.J. Thomson Avenue, Cambridge CB3 0HE (United Kingdom); Albino Aguiar, J., E-mail: albino@df.ufpe.br [Programa de Pós-Graduação em Ciências de Materiais, Centro de Ciências Exatas e da Natureza, Universidade Federal de Pernambuco, 50670-901 Recife-PE (Brazil); Departamento de Física, Universidade Federal de Pernambuco, 50670-901 Recife-PE (Brazil)

    2013-10-15

    In this work we report the preparation of fucan-coated magnetite (Fe{sub 3}O{sub 4}) nanoparticles by the co-precipitation method. These nanoparticles were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, Mössbauer spectroscopy and magnetic measurements. The nanoparticles showed quasi-spherical morphology with mean sizes around 10 nm. XRD and FT-IR confirmed the functionalization of the Fe{sub 3}O{sub 4} nanoparticles with the fucan polysaccharide. Room temperature magnetization measurements and Mössbauer spectroscopy showed that the nanoparticles exhibited superparamagnetic behavior at 300 K and the magnetic properties of the Fe{sub 3}O{sub 4} are partly screened by the coating preventing aggregation. - Highlights: • Syntheses of fucan-coated Fe{sub 3}O{sub 4} nanoparticles were made by co-precipitation method. • The efficiency of polysaccharide coated was analyzed by XRD and FT-IR. • The magnetic nanoparticles mean size was 10–20 nm. • The fucan-coated magnetite nanoparticles showed superparamagnetic behavior.

  18. Silver Nanoparticles Synthesized Using Wild Mushroom Show Potential Antimicrobial Activities against Food Borne Pathogens

    Directory of Open Access Journals (Sweden)

    Yugal Kishore Mohanta

    2018-03-01

    Full Text Available The present study demonstrates an economical and eco-friendly method for the synthesis of silver nanoparticles (AgNPs using the wild mushroom Ganoderma sessiliforme. The synthesis of AgNPs was confirmed and the products characterized by UV-visible spectroscopy, dynamic light scattering spectroscopy and X-ray diffraction analysis. Furthermore, Fourier transform infrared spectroscopy (ATR-FTIR analysis was performed to identify the viable biomolecules involved in the capping and active stabilization of AgNPs. Moreover, the average sizes and morphologies of AgNPs were analyzed by field emission scanning electron microscopy (FE-SEM. The potential impacts of AgNPs on food safety and control were evaluated by the antimicrobial activity of the synthesized AgNPs against common food-borne bacteria, namely, Escherichia coli, Bacillus subtilis, Streptococcus faecalis, Listeria innocua and Micrococcus luteus. The results of this study revealed that the synthesized AgNPs can be used to control the growth of food-borne pathogens and have potential application in the food packaging industry. Moreover, the AgNPs were evaluated for antioxidant activity (DPPH, for biocompatibility (L-929, normal fibroblast cells, and for cytotoxic effects on human breast adenosarcoma cells (MCF-7 & MDA-MB231 to highlight their potential for use in a variety of bio-applications.

  19. A simple approach to design chitosan functionalized Fe3O4 nanoparticles for pH responsive delivery of doxorubicin for cancer therapy

    Science.gov (United States)

    Adimoolam, Mahesh G.; Amreddy, Narsireddy; Nalam, Madhusudana Rao; Sunkara, Manorama V.

    2018-02-01

    The use of magnetic nanoparticles (MNPs) in cancer therapy offer many advantages due to their unique size, physical and biocompatible properties. In this study we have developed a formulation, comprising of anti-cancer drug doxorubicin (Dox) conjugated to iron oxide nanoparticles via a pH sensitive imine linker. Different amounts of chitosan functionalized superparamagnetic iron oxide nanoparticles (Fe3O4-CHI) were synthesized in-situ by a simple hydrolysis method at room temperature. The synthesized nanoparticles were well characterized by TEM, Zeta Potential, TOC, XPS, TGA and VSM for their physicochemical properties. Dox was conjugated to the Fe3O4-CHI nanoparticles via a glutaraldehyde cross linker with the imine (sbnd Cdbnd Nsbnd) bond, which is sensitive to cleavage in the pH range of 4.4-6.4. The synthesized Fe3O4-Dox nanoparticles exhibited enhanced drug release in lower pH conditions which mimics the tumor microenvironment or intracellular organelles such as endosomes/lysosomes. The cell uptake and therapeutic efficacy of Fe3O4-Dox nanoparticles carried out in ovarian cancer cell (SK-OV-3) and breast cancer cell line (MCF7) showed improved therapeutic efficacy of Dox by nearly four-fold with Fe3O4-Dox nanoparticles.

  20. Monodisperse magnetite (Fe_3O_4) nanoparticles modified with water soluble polymers for the diagnosis of breast cancer by MRI method

    International Nuclear Information System (INIS)

    Rezayan, Ali Hossein; Mousavi, Majid; Kheirjou, Somayyeh; Amoabediny, Ghasem; Ardestani, Mehdi Shafiee; Mohammadnejad, Javad

    2016-01-01

    In this study, magnetic nanoparticles (MNPs) were synthesized via co-precipitation method. To enhance the biocompatibility and colloidal stability of the synthesized nanoparticles, they were modified with carboxyl functionalized PEG via dopamine (DPA) linker. Both modified and unmodified Fe_3O_4 nanoparticles exhibited super paramagnetic behavior (particle size below 20 nm). The saturation magnetization (Ms) of PEGdiacid-modified Fe_3O_4 was 45 emu/g, which was less than the unmodified Fe_3O_4 nanoparticles (70 emu/g). This difference indicated that PEGdiacid polymer was immobilized on the surface of Fe_3O_4 nanoparticles successfully. To evaluate the efficiency of the resulting nanoparticles as contrast agents for magnetic resonance imaging (MRI), different concentration of MNPs and different value of echo time TE were investigated. The results showed that by increasing the concentration of the nanoparticles, transverse relaxation time (T_2) decreased, which subsequently resulted in MR signal enhancement. T_2-weighted MR images of the different concentration of MNPs in different value of echo time TE indicated that MR signal intensity increased with increase in TE value up to 66 and then remained constant. The cytotoxicity effect of the modified and unmodified nanoparticles was evaluated in three different concentrations (12, 60 and 312 mg l"−"1) on MDA-MB-231 cancer cells for 24 and 48 h. In both tested time (24 and 48 h) for all three samples, the modified nanoparticles had long life time than unmodified nanoparticles. Cellular uptake of modified MNPs was 80% and reduced to 9% by the unmodified MNPs. - Highlights: • Magnetic nanoparticles (MNPs) were synthesized via co-precipitation method. • MNPs were modified with carboxyl functionalized PEG via dopamine (DPA) linker. • Modified and unmodified Fe_3O_4 nanoparticles exhibited super paramagnetic behavior. • T_2 decrease as MNPs concentration increase, this led to MR signal enhancement. • Modified

  1. Gum arabic modified Fe3O4 nanoparticles cross linked with collagen for isolation of bacteria

    Directory of Open Access Journals (Sweden)

    Chittor Raghuraman

    2010-12-01

    Full Text Available Abstract Background Multifunctional magnetic nanoparticles are important class of materials in the field of nanobiotechnology, as it is an emerging area of research for material science and molecular biology researchers. One of the various methods to obtain multifunctional nanomaterials, molecular functionalization by attaching organic functional groups to nanomagnetic materials is an important technique. Recently, functionalized magnetic nanoparticles have been demonstrated to be useful in isolation/detection of dangerous pathogens (bacteria/viruses for human life. Iron (Fe based material especially FePt is used in the isolation of ultralow concentrations (2 cfu/ml of bacteria in less time and it has been demonstrated that van-FePt may be used as an alternative fast detection technique with respect to conventional polymerase chain reaction (PCR method. However, still further improved demonstrations are necessary with interest to biocompatibility and green chemistry. Herein, we report the synthesis of Fe3O4 nanoparticles by template medication and its application for the detection/isolation of S. aureus bacteria. Results The reduction of anhydrous Iron chloride (FeCl3 in presence of sodium borohydride and water soluble polyelectrolyte (polydiallyldimethyl ammonium chloride, PDADMAC produces black precipitates. The X-ray diffraction (XRD, XPS and TEM analysis of the precipitates dried at 373 K demonstrated the formation of nanocrystalline Fe3O4. Moreover, scanning electron microscopy (SEM showed isolated staphylococcous aureus (S. aureus bacteria at ultralow concentrations using collagen coated gum arabic modified iron oxide nanoparticles (CCGAMION. Conclusion We are able to synthesize nanocrystalline Fe3O4 and CCGAMION was able to isolate S. aureus bacteria at 8-10 cfu (colony forming units/ml within ~3 minutes.

  2. Synthesis, characterization and surface modification of ZnCrFeO{sub 4} nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Hamed, Amal [Carnegie Laboratory of Physics, School of Engineering, Physics and Mathematics, University of Dundee, Dundee, DD1 4HN (United Kingdom); Fitzgerald, Alexander G., E-mail: a.g.fitzgerald@dundee.ac.uk [Carnegie Laboratory of Physics, School of Engineering, Physics and Mathematics, University of Dundee, Dundee, DD1 4HN (United Kingdom); Wang, Lijun; Gueorguieva, Mariana; Malik, Ritu; Melzer, Andreas [Institute for Medical Science and Technology, University of Dundee, Dundee, DD2 1FD (United Kingdom)

    2013-04-01

    The aim of this research was to investigate zinc chromium ferrite (ZnCrFeO{sub 4}) nanoparticles, synthesized using the sol gel technique with nanoparticle size controlled through a two-stage annealing process. Stage one was a low temperature firing which produced low quality nanocrystals with an average size of 15 nm. This was followed by a second firing stage at high temperature which enhanced the crystal quality. The nanoparticles were then coated with a bio-compatible shell to form a stable suspension in the ferrofluid carrier. The resulting nanoparticles were found by electron microscopy, atomic force microscopy and X-ray diffraction studies to have excellent crystal quality. The average size was 8.5 nm. Preliminary cell culture studies indicated the ZnCrFeO{sub 4} nanoparticles were non-toxic. The relatively high measured value of the relaxivity r{sub 2} showed that the nanoparticle coating was effective in substantially reducing aggregation and enhancing the properties of the nanoparticles associated with contrast enhancement in MRI. - Highlights: ► Novel two stage process produced optimal size and quality ZnCrFeO{sub 4} nanocrystals. ► We examined quality by electron and atomic force microscopy and X-ray diffraction. ► Average nanoparticle size of the, order of 10 nm, was determined by five methods. ► Relaxivity studies indicate possible use as negative contrast agent for MRI. ► Cell culture work shows that the nanocrystals have possible biomedical applications.

  3. Characterization of hydrothermally synthesized SnS nanoparticles for solar cell application

    Science.gov (United States)

    Rajwar, Birendra Kumar; Sharma, Shailendra Kumar

    2018-05-01

    In the present study, SnS nanoparticles were synthesized by simple hydrothermal method using stannous chloride and thiourea as tin (Sn) and sulfur (S) precursor respectively. Synthesized nanoparticles were characterized by X-ray diffraction (XRD), Field Emission Scanning Electron Microscopy and UV-Vis Spectroscopy techniques. XRD pattern reveals that as-prepared nanoparticles exhibit orthorhombic structure. Average particles size was calculated using Scherrer's formula and found to be 23 nm. FESEM image shows that the as-prepared nanoparticles are in plate like structure. Direct optical band gap (Eg) of as-synthesized nanoparticles was calculated through UV-Vis Spectroscopy measurement and found to be 1.34 eV, which is near to optimum need for photovoltaic solar energy conversion (1.5 eV). Thus this SnS, narrowband gap semiconductor material can be applied as an alternative absorber material for solar cell application.

  4. Calcination temperature influenced multiferroic properties of Ca-doped BiFeO3 nanoparticles

    International Nuclear Information System (INIS)

    Dhir, Gitanjali; Uniyal, Poonam; Verma, N. K.

    2015-01-01

    The influence of Ca-doping and particle size on structural, morphological and magnetic properties of BiFeO 3 nanoparticles has been studied. A sol-gel method was employed for the synthesis of nanoparticles and their particle size was tailored by varying the calcination temperature. Structural analysis revealed a rhombohedral distortion induced by Ca-substitution. The broadening of diffraction peaks with decreasing calcination temperature was indicative of reduction in crystallite size. The morphological analysis revealed the formation of agglomerated nanoparticles having average particle size ranging from 10-15 and 50-55 nm for C4 and C6, respectively. The agglomeration is attributed to high surface energy of nanoparticles. Ferromagnetism has been displayed by all the synthesized nanoparticles. Enhancement of saturation magnetization with Ca-substitution is attributed to suppression of spin cycloid structure by the reduction in size, lattice distortion and creation of oxygen vacancies by the substitution of divalent ion at trivalent site. Further, this value increases as a function of decreasing particle size. Strong particle size effects on magnetic properties of the synthesized nanoparticles are owed to increasing surface to volume ratio. All these observations are indicative of strong dependence of multiferroism on particle size

  5. Distinction between SnO2 nanoparticles synthesized using co ...

    Indian Academy of Sciences (India)

    Administrator

    pared with that of a co-precipitation-modified SnO2 nanoparticles. Keywords. SnO2 nanoparticle ... Dye-sensitized solar cells (DSSCs), which convert light to electricity by means of ... nature, additives and aging time. Nanosized particles pre-.

  6. Magnetic properties of γ-Fe2O3 nanoparticles incorporated in a polystyrene resin matrix

    Science.gov (United States)

    Vaishnava, P. P.; Senaratne, U.; Buc, E. C.; Naik, R.; Naik, V. M.; Tsoi, G. M.; Wenger, L. E.

    2007-07-01

    γ-Fe2O3 magnetic nanoparticles ranging in average diameter from 3to10nm were synthesized into a polystyrene resin matrix by an ion-exchange method and characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), Mössbauer spectroscopy, and SQUID magnetometry. The average particle size as determined from XRD and TEM was found to be strongly dependent upon the initial Fe valence state of the starting chloride salt(s) and on the number of steps that the salt introduction and ion-exchange process were repeated. Regardless of the initial Fe valence state and processing conditions, Mössbauer spectroscopy confirmed that the Fe in the resulting nanoparticles existed only as Fe(III) ions and that γ-Fe2O3 was the only phase present. The values of the saturation magnetization at 5K were found to be dependent upon the processing conditions and ranged from 203to333emu/cm3 , which are significantly smaller than the bulk value (408emu/cm3) for γ-Fe2O3 . As expected, the nanoparticles exhibited superparamagnetic behavior with the magnetic moments becoming frozen with decreasing temperature as evidenced by the appearance of a six-line splitting in the Mössbauer spectra, a bifurcation in the zero-field-cooled (ZFC) and field-cooled (FC) magnetizations, and an opening in the MV -vs- H hysteresis curves. The values of magnetic anisotropy constant (1.2-2.1×106ergs/cm3) determined from the differences between the ZFC and FC magnetizations were found to be higher than the bulk value (1.1×105ergs/cm3) for γ-Fe2O3 , and are probably due to surface effects. Likewise, the nanoparticle size distributions as deduced from the blocking temperature distribution function f(TB) based on fits to the difference in the ZFC and FC magnetization curves as well as from fits of the MV -vs- H curves in the superparamagnetic regime with a Langevin function indicate fairly broad distributions of particle sizes with the particle sizes being comparable to those deduced from XRD

  7. Structure and Plasmonic Properties of Thin PMMA Layers with Ion-Synthesized Ag Nanoparticles

    DEFF Research Database (Denmark)

    Popok, Vladimir; Hanif, Muhammad; Mackova, Anna

    2015-01-01

    nanoparticles above the surface. The synthesized nanoparticles can be split into two groups: (i) located at the surface and (ii) fully embedded in the shallow layer. These two groups provide corresponding spectral bands related to localized surface plasmon resonance. The bands demonstrate considerable intensity...

  8. Synthesis, characterization and adsorption capability for Congo red of CoFe{sub 2}O{sub 4} ferrite nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Zui [State Key Laboratory of Chemical Resource Engineering and School of Science, Beijing University of Chemical Technology, Beijing 100029 (China); Beijing Key Laboratory of Environmentally Harmful Chemical Analysis, Beijing University of Chemical Technology, Beijing 100029 (China); Wang, Wei, E-mail: wangwei@mail.buct.edu.cn [State Key Laboratory of Chemical Resource Engineering and School of Science, Beijing University of Chemical Technology, Beijing 100029 (China); Beijing Key Laboratory of Environmentally Harmful Chemical Analysis, Beijing University of Chemical Technology, Beijing 100029 (China); Zhang, Yajun [Institute of Plastics Machinery and Engineering, Beijing University of Chemical Technology, Beijing 100029 (China); Li, Feng [State Key Laboratory of Chemical Resource Engineering and School of Science, Beijing University of Chemical Technology, Beijing 100029 (China); Liu, J. Ping [Department of Physics, University of Texas at Arlington, Arlington, TX 76019 (United States)

    2015-08-15

    Highlights: • CoFe{sub 2}O{sub 4} ferrite nanoparticles are synthesized by an ethanol-assisted hydrothermal method. • Suitable amount of ethanol can reduce the particle size and increase BET surface area. • The introduction of ethanol leads to the cation redistribution. • Using ethanol/water mixed solution greatly enhances their adsorption capacity for CR dyes. - Abstract: CoFe{sub 2}O{sub 4} ferrite nanoparticles are synthesized by an ethanol-assisted hydrothermal method, where the ethanol is mixed with water as the solution. In this synthesis, a rapid mixing of reducible metal cations with reducing agent and a simultaneous reduction process take place in a colloid mill. Synthesized ferrite samples are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), vibrating sample magnetometer (VSM) and Raman spectroscopy. XRD patterns reveal the formation of CoFe{sub 2}O{sub 4} ferrites with single spinel phase. SEM and TEM images show that the as-synthesized samples are with narrow size distribution. Raman spectroscopy studies clearly indicate the cation distribution in nanosized particles. Here, it is worthy to note that, with increasing ethanol content in ethanol–water mixed solution, an obvious superparamagnetic behavior of as-synthesized nanoparticles at room temperature is observed. The adsorption capability of the as-synthesized ferrite nanoparticles for Congo Red (CR) is examined. Enhancement of adsorption capability for CR with adding ethanol as the mixing solution is shown. The adsorption mechanism is discussed. This investigation reveals that the composition of ethanol/water mixed solution has great effects on the microstructure and magnetic properties as well as adsorption capacity of Congo Red (CR) dye of the as-synthesized CoFe{sub 2}O{sub 4} ferrite samples.

  9. Synthesis, characterization and adsorption capability for Congo red of CoFe2O4 ferrite nanoparticles

    International Nuclear Information System (INIS)

    Ding, Zui; Wang, Wei; Zhang, Yajun; Li, Feng; Liu, J. Ping

    2015-01-01

    Highlights: • CoFe 2 O 4 ferrite nanoparticles are synthesized by an ethanol-assisted hydrothermal method. • Suitable amount of ethanol can reduce the particle size and increase BET surface area. • The introduction of ethanol leads to the cation redistribution. • Using ethanol/water mixed solution greatly enhances their adsorption capacity for CR dyes. - Abstract: CoFe 2 O 4 ferrite nanoparticles are synthesized by an ethanol-assisted hydrothermal method, where the ethanol is mixed with water as the solution. In this synthesis, a rapid mixing of reducible metal cations with reducing agent and a simultaneous reduction process take place in a colloid mill. Synthesized ferrite samples are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), vibrating sample magnetometer (VSM) and Raman spectroscopy. XRD patterns reveal the formation of CoFe 2 O 4 ferrites with single spinel phase. SEM and TEM images show that the as-synthesized samples are with narrow size distribution. Raman spectroscopy studies clearly indicate the cation distribution in nanosized particles. Here, it is worthy to note that, with increasing ethanol content in ethanol–water mixed solution, an obvious superparamagnetic behavior of as-synthesized nanoparticles at room temperature is observed. The adsorption capability of the as-synthesized ferrite nanoparticles for Congo Red (CR) is examined. Enhancement of adsorption capability for CR with adding ethanol as the mixing solution is shown. The adsorption mechanism is discussed. This investigation reveals that the composition of ethanol/water mixed solution has great effects on the microstructure and magnetic properties as well as adsorption capacity of Congo Red (CR) dye of the as-synthesized CoFe 2 O 4 ferrite samples

  10. Cytotoxic Effect on Cancerous Cell Lines by Biologically Synthesized Silver Nanoparticles

    Directory of Open Access Journals (Sweden)

    Balaji Kulandaivelu

    Full Text Available The biosynthesis of nanoparticles has been proposed as an environmental friendly and cost effective alternative to chemical and physical methods. Silver nanoparticles are biologically synthesized and characterized were used in the study. The invitro cytotoxic effect of biologically synthesized silver nanoparticles against MCF-7 cancer cell lines were assessed. The cytotoxic effects of the silver nanoparticles could significantly inhibited MCF-7 cancer cell lines proliferation in a time and concentration-dependent manner by MTT assay. Acridine orange, ethidium bromide (AO/EB dual staining, caspase-3 and DNA fragmentation assays were carried out using various concentrations of silver nanoparticles ranging from 1 to 100 μg/mL. At 100 μg/mL concentration, the silver nanoparticles exhibited significant cytotoxic effects and the apoptotic features were confirmed through caspase-3 activation and DNA fragmentation assays. Western blot analysis has revealed that nanoparticle was able to induce cytochrome c release from the mitochondria, which was initiated by the inhibition of Bcl-2 and activation of Bax. Thus, the results of the present study indicate that biologically synthesized silver nanoparticles might be used to treat breast cancer. The present studies suggest that these nanoparticles could be a new potential adjuvant chemotherapeutic and chemo preventive agent against cytotoxic cells. However, it necessitates clinical studies to ascertain their potential as anticancer agents.

  11. Interaction between serum albumins and sonochemically synthesized cadmium sulphide nanoparticles: a spectroscopic study

    International Nuclear Information System (INIS)

    Naveenraj, Selvaraj; Asiri, Abdullah M.; Anandan, Sambandam

    2013-01-01

    Cadmium Sulphide nanoparticles approximately 5–10 nm in size range were synthesized by sonochemical technique, which follows acoustic cavitation phenomenon and generates nanoparticles with a smaller size range and higher surface area. The in vitro binding interaction of these sonochemically synthesized CdS nanoparticles with serum albumins (SA) were investigated using UV–Vis absorption, fluorescence and circular dichroism (CD) spectroscopic techniques since CdS nanoparticles has biological applications such as cellular labelling and deep-tissue imaging. UV–Vis absorption and fluorescence studies confirm that CdS nanoparticles bind with SA through ground state complex formation (static quenching mechanism). The results suggest that sonochemically synthesized CdS nanoparticles interact with HSA more than that of BSA and these nanoparticles can be easily transported and rapidly released to the targets by serum albumins. CD studies confirmed the conformational change of serum albumins on the interaction of CdS nanoparticles.Graphical AbstractThis paper investigates the in vitro binding interaction of Cadmium Sulphide (CdS) nanoparticles with serum albumins (HSA and BSA) using the UV-vis, steady-state fluorescence, time-resolved fluorescence, synchronous fluorescence and circular dichroism (CD) spectral techniques.

  12. Schiff Base Ligand Coated Gold Nanoparticles for the Chemical Sensing of Fe(III Ions

    Directory of Open Access Journals (Sweden)

    Abiola Azeez Jimoh

    2015-01-01

    Full Text Available New Schiff base-coated gold nanoparticles (AuNPs of type AuNP@L (where L: thiolated Schiff base ligand have been synthesized and characterized using various spectroscopic techniques. The AuNPs and AuNP@L were imaged by transmission electron microscopy (TEM and were confirmed to be well-dispersed, uniformly distributed, spherical nanoparticles with an average diameter of 8–10 nm. Their potential applications for chemosensing were investigated in UV-Vis and fluorescence spectroscopic studies. The AuNP@L exhibited selectivity for Fe3+ in an ethanol/water mixture (ratio 9 : 1 v/v. The absorption and emission spectral studies revealed a 1 : 1 binding mode for Fe3+, with binding constants of 8.5×105 and 2.9×105 M−1, respectively.

  13. Morphology and dispersion of FeCo alloy nanoparticles dispersed in a matrix of IR pyrolized polyvinyl alcohol

    Science.gov (United States)

    Vasilev, A. A.; Dzidziguri, E. L.; Muratov, D. G.; Zhilyaeva, N. A.; Efimov, M. N.; Karpacheva, G. P.

    2018-04-01

    Metal-carbon nanocomposites consisting of FeCo alloy nanoparticles dispersed in a carbon matrix were synthesized by the thermal decomposition method of a precursor based on polyvinyl alcohol and metals salts. The synthesized powders were investigated by X-ray diffraction (XRD), X-ray fluorescent spectrometry (XRFS), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Surface characteristics of materials were measured by BET-method. The morphology and dispersity of metal nanoparticles were studied depending on the metals ratio in the composite.

  14. Evaluation of antioxidant, antibacterial and cytotoxic effects of green synthesized silver nanoparticles by Piper longum fruit

    Energy Technology Data Exchange (ETDEWEB)

    Reddy, N. Jayachandra; Nagoor Vali, D.; Rani, M.; Rani, S. Sudha, E-mail: sadrassudha@gmail.com

    2014-01-01

    Silver nanoparticles synthesized through bio-green method has been reported to have biomedical applications to control pathogenic microbes as it is cost effective compared to commonly used physical and chemical methods. In present study, silver nanoparticles were synthesized using aqueous Piper longum fruit extract (PLFE) and confirmed by UV–visible spectroscopy. The nanoparticles were spherical in shape with an average particle size of 46 nm as determined by scanning electronic microscopy (SEM) and dynamic light scattering (DLS) particle size analyzer respectively. FT-IR spectrum revealed the capping of the phytoconstituents, probably polyphenols from P. longum fruit extract and stabilizing the nanoparticles. Further the ferric ion reducing test, confirmed that the capping agents were condensed tannins. The aqueous P. longum fruit extract (PLFE) and the green synthesized silver nanoparticles (PLAgNPs) showed powerful antioxidant properties in in vitro antioxidant assays. The results from the antimicrobial assays suggested that green synthesized silver nanoparticles (PLAgNPs) were more potent against pathogenic bacteria than the P. longum fruit extract (PLFE) alone. The nanoparticles also showed potent cytotoxic effect against MCF-7 breast cancer cell lines with an IC 50 value of 67 μg/ml/24 h by the MTT assay. These results support the advantages of using bio-green method for synthesizing silver nanoparticles with antioxidant, antimicrobial and cytotoxic activities those are simple and cost effective as well. - Highlights: • 46 nm spherical shaped P. longum fruit silver nanoparticles was prepared. • Capping and reducing bioactive plant compounds with in nanoparticles were condensed tannins. • Particles are potent antioxidant and anti microbial in biological systems. • They are cytotoxic against MCF-7 cell lines.

  15. Evaluation of antioxidant, antibacterial and cytotoxic effects of green synthesized silver nanoparticles by Piper longum fruit

    International Nuclear Information System (INIS)

    Reddy, N. Jayachandra; Nagoor Vali, D.; Rani, M.; Rani, S. Sudha

    2014-01-01

    Silver nanoparticles synthesized through bio-green method has been reported to have biomedical applications to control pathogenic microbes as it is cost effective compared to commonly used physical and chemical methods. In present study, silver nanoparticles were synthesized using aqueous Piper longum fruit extract (PLFE) and confirmed by UV–visible spectroscopy. The nanoparticles were spherical in shape with an average particle size of 46 nm as determined by scanning electronic microscopy (SEM) and dynamic light scattering (DLS) particle size analyzer respectively. FT-IR spectrum revealed the capping of the phytoconstituents, probably polyphenols from P. longum fruit extract and stabilizing the nanoparticles. Further the ferric ion reducing test, confirmed that the capping agents were condensed tannins. The aqueous P. longum fruit extract (PLFE) and the green synthesized silver nanoparticles (PLAgNPs) showed powerful antioxidant properties in in vitro antioxidant assays. The results from the antimicrobial assays suggested that green synthesized silver nanoparticles (PLAgNPs) were more potent against pathogenic bacteria than the P. longum fruit extract (PLFE) alone. The nanoparticles also showed potent cytotoxic effect against MCF-7 breast cancer cell lines with an IC 50 value of 67 μg/ml/24 h by the MTT assay. These results support the advantages of using bio-green method for synthesizing silver nanoparticles with antioxidant, antimicrobial and cytotoxic activities those are simple and cost effective as well. - Highlights: • 46 nm spherical shaped P. longum fruit silver nanoparticles was prepared. • Capping and reducing bioactive plant compounds with in nanoparticles were condensed tannins. • Particles are potent antioxidant and anti microbial in biological systems. • They are cytotoxic against MCF-7 cell lines

  16. Preparation of CNC-dispersed Fe3O4 nanoparticles and their application in conductive paper.

    Science.gov (United States)

    Liu, Kai; Nasrallah, Joseph; Chen, Lihui; Huang, Liulian; Ni, Yonghao

    2015-08-01

    Well-dispersed Fe3O4 nanoparticles (NPs) were synthesized by a co-precipitation method in the presence of cellulose nano-crystals (CNC) as the template. The thus prepared Fe3O4 NPs were then used as a coating agent for the preparation of conductive paper. Fourier transform infrared spectroscopy (FTIR) results revealed that the Fe3O4 NPs were immobilized on the CNC through interactions between the hydroxyl groups of CNC and Fe3O4. Scanning transmission electron microscopy (STEM) images showed that the Fe3O4 NPs prepared in the presence of CNC can be dispersed in the CNC network, while the Fe3O4 NPs prepared in the absence of CNC tended to aggregate in aqueous solutions. The conductivity of the Fe3O4 NPs coated paper can reach to 0.0269 S/m at the coating amount of 14.75 g/m(2) Fe3O4/CNC nanocomposites. Therefore, the thus obtained coated paper can be potentially used as anti-static packaging material in the packaging field. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Bio-inspired green synthesis of Fe3O4 magnetic nanoparticles using watermelon rinds and their catalytic activity

    Science.gov (United States)

    Prasad, Ch.; Gangadhara, S.; Venkateswarlu, P.

    2016-08-01

    Novel and bio-inspired magnetic nanoparticles were synthesized using watermelon rinds (WR) which are nontoxic and biodegradable. Watermelon rind extract was used as a solvent and capping and reducing agent in the synthesis. The Fe3o4 MNPs were characterized by using transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and vibrating sample magnetometer techniques (VSM). XRD studies revealed a high degree of crystalline and monophasic Fe nanoparticles of face-centered cubic stricture. FTIR analysis proved that particles are reduced and stabilized in solution by the capping agent that is likely to be proteins secreted by the biomass. The present process in an excellent candidate for the synthesis of iron nanoparticles that is simple, easy to execute, pollutant free and inexpensive. A practical and convenient method for the synthesis of highly stable and small-sized iron nanoparticles with a narrow distribution from 2 to 20 nm is reported. Also, the MNPs present in higher saturation magnetization (Ms) of 14.2 emu/g demonstrate tremendous magnetic response behavior. However, the synthesized iron nanoparticles were used as a catalyst for the preparation of biologically interesting 2-oxo-1,2,3,4-tetrahydropyrimidine derivatives in high yields. These results exhibited that the synthesized Fe3O4 MNPs could be used as a catalyst in organic synthesis.

  18. Sonochemically synthesized iron-doped zinc oxide nanoparticles: Influence of precursor composition on characteristics

    International Nuclear Information System (INIS)

    Roy, Anirban; Maitra, Saikat; Ghosh, Sobhan; Chakrabarti, Sampa

    2016-01-01

    Highlights: • Sonochemical synthesis of iron-doped zinc oxide nanoparticles. • Green synthesis without alkali at room temperature. • Characterization by UV–vis spectroscopy, FESEM, XRD and EDX. • Influence of precursor composition on characteristics. • Composition and characteristics are correlated. - Abstract: Iron-doped zinc oxide nanoparticles have been synthesized sonochemically from aqueous acetyl acetonate precursors of different proportions. Synthesized nanoparticles were characterized with UV–vis spectroscopy, X-ray diffraction and microscopy. Influences of precursor mixture on the characteristics have been examined and modeled. Linear correlations have been proposed between dopant dosing, extent of doping and band gap energy. Experimental data corroborated with the proposed models.

  19. and α-Fe 2 O 3 nano powders synthesized by emulsion precipitation

    African Journals Online (AJOL)

    Nano crystals of γ-Fe2O3 (maghemite) were synthesized by emulsion precipitation method using kerosene as oil phase, SPAN- 80 (sorbitane monooleate) as the surfactant and sodium hydroxide as the precipitating agent. The characterization of the samples by FTIR (Fourier transform infra-red) and XRD (X-ray diffraction) ...

  20. Study of static and dynamic magnetic properties of Fe nanoparticles composited with activated carbon

    Energy Technology Data Exchange (ETDEWEB)

    Pal, Satyendra Prakash, E-mail: sppal85@gmail.com [School of Physical Sciences, Jawaharlal Nehru University, New Delhi-110067 (India); Department of Physical Sciences, Indian Institute of Science Education and Research, Mohali, Knowledge city, Sector81, SAS Nagar, Manauli-140306, Punjab (India); Kaur, Guratinder [Department of Physical Sciences, Indian Institute of Science Education and Research, Mohali, Knowledge city, Sector81, SAS Nagar, Manauli-140306, Punjab (India); Sen, P. [School of Physical Sciences, Jawaharlal Nehru University, New Delhi-110067 (India)

    2016-05-23

    Nanocomposite of Fe nanoparticles with activated carbon has been synthesized to alter the magnetic spin-spin interaction and hence study the dilution effect on the static and dynamic magnetic properties of the Fe nanoparticle system. Transmission electron microscopic (TEM) image shows the spherical Fe nanoparticles dispersed in carbon matrix with 13.8 nm particle size. Temperature dependent magnetization measurement does not show any blocking temperature at all, right up to the room temperature. Magnetic hysteresis curve, taken at 300 K, shows small value of the coercivity and this small hysteresis indicates the presence of an energy barrier and inherent magnetization dynamics. Langevin function fitting of the hysteresis curve gives almost similar value of particle size as obtained from TEM analysis. Magnetic relaxation data, taken at a temperature of 100 K, were fitted with a combination of two exponentially decaying function. This diluted form of nanoparticle system, which has particles size in the superparamagnetic limit, behaves like a dilute ensemble of superspins with large value of the magnetic anisotropic barrier.

  1. Preparation and characterization of bifunctional dendrimer modified Fe{sub 3}O{sub 4}/CdTe nanoparticles with both luminescent and superparamagnetic properties

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xiuling, E-mail: wxling_self@163.com [Department of Chemical and Biological Engineering, Suzhou University of Science and Technology, Suzhou 215009 (China); Gu, Yinjun; Dong, Shuling [Department of Chemical and Biological Engineering, Suzhou University of Science and Technology, Suzhou 215009 (China); Zhao, Qin [School of Chemistry and Chemical Engineering, Nantong University, Nantong, Jiangsu 226019 (China); Liu, Yongjian [Department of Chemical and Biological Engineering, Suzhou University of Science and Technology, Suzhou 215009 (China)

    2015-10-15

    Highlights: • The fluorescent superparamagnetic dendrimeric Fe{sub 3}O{sub 4}/CdTe nanoparticles are synthesized in this paper. • The synthesized nanocomposites maintain excellent magnetic properties. • The synthesized nanocomposites maintain highly luminescent markers with narrow emission bands. - Abstract: Magnetic nanoparticles Fe{sub 3}O{sub 4} were prepared by hydrothermal coprecipitation of ferric and ferrous ions using NaOH. The surface modification of Fe{sub 3}O{sub 4} nanoparticle by dendrimers has rendered the nanoparticle surface with enriched amine groups which facilitated the adsorption and conjugation of thioglycolic acid (TGA) modified CdTe quantum dots to form a stable hybrid nanostructure. Three generations (first generation: G0F, second generation: G1F, third generation: G3F) of bifunctional dendrimeric Fe{sub 3}O{sub 4}/CdTe nanoparticles were successfully prepared using this technique and characterized by microscopy. The optical and magnetic properties of the dendrimeric Fe{sub 3}O{sub 4}/CdTe nanoparticle were also investigated. The microscopic study reveals 3 different sizes for 3 generations, 16 nm (G0F), 31 nm (G1F) and 47 nm (G3F). Among three generations of nanoparticles, the G1F has the best optical property with a luminescent quantum yield of 25.6% and the G0F has the best magnetic property with a saturation magnetization of 19.3 emμ/g.

  2. Evaluation of superparamagnetic and biocompatible properties of mesoporous silica coated cobalt ferrite nanoparticles synthesized via microwave modified Pechini method

    Energy Technology Data Exchange (ETDEWEB)

    Gharibshahian, M. [Faculty of New Sciences and Technologies, Semnan University, Semnan (Iran, Islamic Republic of); Mirzaee, O., E-mail: O_mirzaee@semnan.ac.ir [Faculty of Materials and Metallurgical Engineering, Semnan University, Semnan (Iran, Islamic Republic of); Nourbakhsh, M.S. [Faculty of New Sciences and Technologies, Semnan University, Semnan (Iran, Islamic Republic of)

    2017-03-01

    Cobalt ferrite nano particles were synthesized by Pechini sol-gel method and calcined at 700 °C in electrical and microwave furnace. The microwave calcined sample was coated with mesoporous silica by hydrothermal method. Characterization was performed by XRD, FESEM, TEM, VSM, BET and FTIR analysis. The cytotoxicity was evaluated by MTT assay with 3T3 fibroblast cells. The XRD and FTIR results confirmed spinal formation in both cases and verified the formation of silica coating on the nanoparticles. For microwave calcination, The XRD and SEM results demonstrated smaller and flat adhesion forms of nanoparticles with the average size of 15 nm. The VSM results demonstrated nearly superparamagnetic nanoparticles with significant saturation magnetization equal to 64 emu/g. By coating, saturation magnetization was decreased to 36 emu/g. Moreover, the BET results confirmed the formation of mesoporous coating with the average pore diameters of 2.8 nm and average pore volume of 0.82 cm{sup 3} g{sup −1}. Microwave calcined nanoparticles had the best structural and magnetic properties. - Highlights: • CoFe{sub 2}O{sub 4} nanoparticles were synthesized using the microwave modified Pechini method. • The Effect of calcination route and silica coating on NPs properties was studied. • The nearly superparamagnetic nanoparticles were achieved by microwave calcination. • MFC NPs had the best magnetic properties and MTT assay showed no toxicity for MFC-MSC NPs. • A useful scheme was designed to achieve biological superparamagnetic core/shell NPs.

  3. Profound Interfacial Effects in CoFe2O4/Fe3O4 and Fe3O4/CoFe2O4 Core/Shell Nanoparticles

    Science.gov (United States)

    Polishchuk, Dmytro; Nedelko, Natalia; Solopan, Sergii; Ślawska-Waniewska, Anna; Zamorskyi, Vladyslav; Tovstolytkin, Alexandr; Belous, Anatolii

    2018-03-01

    Two sets of core/shell magnetic nanoparticles, CoFe2O4/Fe3O4 and Fe3O4/CoFe2O4, with a fixed diameter of the core ( 4.1 and 6.3 nm for the former and latter sets, respectively) and thickness of shells up to 2.5 nm were synthesized from metal chlorides in a diethylene glycol solution. The nanoparticles were characterized by X-ray diffraction, transmission electron microscopy, and magnetic measurements. The analysis of the results of magnetic measurements shows that coating of magnetic nanoparticles with the shells results in two simultaneous effects: first, it modifies the parameters of the core-shell interface, and second, it makes the particles acquire combined features of the core and the shell. The first effect becomes especially prominent when the parameters of core and shell strongly differ from each other. The results obtained are useful for optimizing and tailoring the parameters of core/shell spinel ferrite magnetic nanoparticles for their use in various technological and biomedical applications.

  4. Controlled synthesis of Fe3O4/ZIF-8 nanoparticles for magnetically separable nanocatalysts.

    Science.gov (United States)

    Pang, Fei; He, Mingyuan; Ge, Jianping

    2015-04-27

    Fe3O4/ZIF-8 nanoparticles were synthesized through a room-temperature reaction between 2-methylimidazolate and zinc nitrate in the presence of Fe3O4 nanocrystals. The particle size, surface charge, and magnetic loading can be conveniently controlled by the dosage of Zn(NO3)2 and Fe3O4 nanocrystals. The as-prepared particles show both good thermal stability (stable to 550 °C) and large surface area (1174 m(2) g(-1)). The nanoparticles also have a superparamagnetic response, so that they can strongly respond to an external field during magnetic separation and disperse back into the solution after withdrawal of the magnetic field. For the Knoevenagel reaction, which is catalyzed by alkaline active sites on external surface of catalyst, small Fe3O4/ZIF-8 nanoparticles show a higher catalytic activity. At the same time, the nanocatalysts can be continuously used in multiple catalytic reactions through magnetic separation, activation, and redispersion with little loss of activity. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. A comparative study of hydroxyapatite nanoparticles synthesized by different routes

    OpenAIRE

    Paz, Adrian; Guadarrama, Dainelys; López, Mónica; E. González, Jesús; Brizuela, Nayrim; Aragón, Javier

    2012-01-01

    In this study, bioactive hydroxyapatite nanoparticles were prepared by two different methods: wet chemical precipitation and biomimetic precipitation. The aim was to evaluate the morphology, particle-size, crystallinity and phases of the powders obtained by traditional wet chemical precipitation and the novel biomimetic precipitation using a supersaturated calcium solution. The nanoparticles were investigated by transmission electron microscopy, Fourier transform infrared spectroscopy and X-r...

  6. Structure and composition of iron nanoparticles synthesized using a novel anionic-element complex

    Energy Technology Data Exchange (ETDEWEB)

    Skoropata, E.; Desautels, R. D.; Lierop, J. van, E-mail: johan@physics.umanitoba.ca [Department of Physics and Astronomy, University of Manitoba, Winnipeg, Manitoba R3T 2N2 (Canada); Rowe, M. [Toyota Research Institute of North America, 1555 Woodridge Ave., Ann Arbor, Michigan 48105 (United States)

    2015-05-07

    We use a novel solution-based disassociation synthesis scheme of the ionic complex Fe(LiBH{sub 4}){sub 2} to form Fe nanoparticles. The complex was formed initially using a gentle mechanochemical process, and the Fe nanoparticles emerged after 4 h of ball milling in an air-free environment. Rietveld refinement of x-ray diffraction measurements in an air-free sample holder identified a Im3{sup ¯}m α-Fe phase. A room temperature Mössbauer spectrum of the sample presented a six-line spectrum unique to Fe{sup 0} metal, and the Fe nanoparticles were extremely well crystallized. Magnetometry results presented a reduced saturation magnetization (e.g., M{sub s}∼ 85 emu/g at 50 K) that had a Bloch-like T{sup 2} temperature dependence, consistent with a gap in the magnon fluctuation spectrum due to finite-size effects. The Fe nanoparticles were magnetically soft, with a coercivity ranging from ∼10 to 20 mT with decreasing temperature from 350 K.

  7. Synthesis and characterization of iron-cobalt (FeCo) alloy nanoparticles supported on carbon

    DEFF Research Database (Denmark)

    Koutsopoulos, Sotiris; Barfod, Rasmus; Eriksen, Kim Michael

    2017-01-01

    of the alloy nanoparticles differed depending on the preparation method. When the wet impregnation technique of acetate precursor salts of Fe and Co were used for the synthesis, the size of FeCo alloy nanoparticles was approximately 13 nm. FeCo alloy nanoparticles were characterized by crystallography (XRD...

  8. Synthesis, Characterizations of Superparamagnetic Fe3O4-Ag Hybrid Nanoparticles and Their Application for Highly Effective Bacteria Inactivation

    DEFF Research Database (Denmark)

    Tung, L.M.; Cong, N.X.; Huy, L.T.

    2016-01-01

    In recent years, outbreaks of infectious diseases caused by pathogenic micro-organisms pose a serious threat to public health. In this work, Fe3O4-Ag hybrid nanoparticles were synthesized by simple chemistry method and these prepared nanoparticles were used to investigate their antibacterial...... with silver nanoparticles can be a potential candidate to effectively treat infectious MRSA pathogen with recyclable capability, targeted bactericidal delivery and minimum release into environment....

  9. Study of structural phase transformation and hysteresis behavior of inverse-spinel α-ferrite nanoparticles synthesized by co-precipitation method

    Science.gov (United States)

    Dabagh, Shadab; Chaudhary, Kashif; Haider, Zuhaib; Ali, Jalil

    2018-03-01

    Substitution of cobalt (Co2+) ions in cobalt ferrite (CoFe2O4) with copper (Cu2+) and aluminum (Al3+) ions allows variations in their electric and magnetic properties which can be optimized for specific applications. In this article, synthesis of inverse-spinel Co1-xCuxFe2-xAlxO4 (0.0 ≤ x ≤ 0.8) nanoparticles by substituting Cu2+ and Al3+ ions in CoFe2O4 via co-precipitation method is reported. By controlling copper and aluminum (Cu-Al) substituent ratio, the magnetic moment and coercivity of synthesized cobalt ferrite nanoparticles is optimized. The role of substituents on the structure, particle size, morphology, and magnetic properties of nano-crystalline ferrite is investigated. The Co1-xCuxFe2-xAlxO4 (0.0 ≤ x≤ 0.8) nanoparticles with crystallite size in the range of 23.1-26.5 nm are observed, 26.5 nm for x = 0.0-23.1 nm for x = 0.8. The inverse-spinel structure of synthesized Co1-xCuxFe2-xAlxO4 (0.0 ≤ x ≤ 0.8) nano-particles is confirmed by characteristic vibrational bands at tetrahedral and octahedral sites using Fourier transform infrared spectroscopy. A decreases in coercive field and magnetic moment is observed as Cu-Al contents are increased (x = 0.0-0.8). The positive anisotropy of synthesized particles Co1-xCuxFe2-xAlxO4 (0.0 ≤ x ≤ 0.8) is obtained in the range 1.96 × 105 J/m3 for x = 0.0 to 0.29 × 105 J/m3 for x = 0.8.

  10. A Study On Dispersion Stability Of Nickel Nanoparticles Synthesized By Wire Explosion In Liquid Media

    Directory of Open Access Journals (Sweden)

    Kim C.K.

    2015-06-01

    Full Text Available In this study, nickel nanoparticles were synthesized in ethanol using portable pulsed wire evaporation, which is a one-step physical method. From transmission electron microscopy images, it was found that the Ni nanoparticles exhibited a spherical shape with an average diameter of 7.3 nm. To prevent aggregation of the nickel nanoparticles, a polymer surfactant was added into the ethanol before the synthesis of nickel nanoparticles, and adsorbed on the freshly synthesized nickel nanoparticles during the wire explosion. The dispersion stability of the prepared nickel nanofluids was investigated by zeta-potential analyzer and Turbiscan optical analyzer. As a result, the optimum concentration of polymer surfactant to be added was suggested for the maximized dispersion stability of the nickel nanofluids.

  11. Large tunneling magnetoresistance in octahedral Fe3O4 nanoparticles

    Directory of Open Access Journals (Sweden)

    Arijit Mitra

    2016-05-01

    Full Text Available We have observed large tunneling Magnetoresistance (TMR in amine functionalized octahedral nanoparticle assemblies. Amine monolayer on the surface of nanoparticles acts as an insulating barrier between the semimetal Fe3O4 nanoparticles and provides multiple tunnel junctions where inter-granular tunneling is plausible. The tunneling magnetoresistance recorded at room temperature is 38% which increases to 69% at 180 K. When the temperature drops below 150 K, coulomb staircase is observed in the current versus voltage characteristics as the charging energy exceeds the thermal energy. A similar study is also carried out with spherical nanoparticles. A 24% TMR is recorded at room temperature which increases to 41% at 180 K for spherical particles. Mössbauer spectra reveal better stoichiometry for octahedral particles which is attainable due to lesser surface disorder and strong amine coupling at the facets of octahedral Fe3O4 nanoparticles. Less stoichiometric defect in octahedral nanoparticles leads to a higher value of spin polarization and therefore larger TMR in octahedral nanoparticles.

  12. Radioiodination of cyclin dependent kinase inhibitor Olomoucine loaded Fe rate at Au nanoparticle and evaluation of the therapeutic efficacy on cancerous cells

    Energy Technology Data Exchange (ETDEWEB)

    Takan, Gokhan; Guldu, Ozge Kozgus; Medine, Emin Ilker [Ege Univ., Izmir (Turkey). Dept. of Nuclear Applications

    2017-06-01

    Magnetic nanoparticles have promising biomedical applications such as drug delivery, novel therapeutics and diagnostic imaging. Magnetic drug delivery combination works on the delivery of magnetic nanoparticles loaded with drug to the target tissue by means of an external magnetic field. Gold coated iron oxide (Fe rate at Au) nanoparticles can provide useful surface chemistry and biological reactivity. Covalent conjugation to the Fe rate at Au nanoparticles through cleavable linkages can be used to deliver drugs to tumor cells, then the drug can be released by an external. In this paper, purine based cyclin dependent kinases (CDKs) inhibitor Olomoucine (Olo) [2-(Hydroxyethylamino)-6-benzylamino-9-methylpurine] was loaded on gold coated iron oxide (Fe rate at Au) nanoparticles and radiolabeled with {sup 131}I to combine magnetic targeted drug delivery and radiotherapy. Fe rate at Au nanoparticles were synthesized by microemulsion method. The characterization of nanoparticles was examined by TEM, VSM and XRD. Amine activation was utilized by cysteamine hydrochloride and then CDI was used for conjugation of Olomoucine. Antiproliferative effect and cytotoxicity of Olomoucine loaded Fe rate at Au nanoparticles (Fe rate at Au-Olo) were investigated on MCF7 and A549 cell lines. Proliferation rate was decreased while uptake of Fe rate at Au-Olo on both cell lines was high in comparison with Olomoucine. Also, enhanced incorporation ratio was observed under external magnetic field.

  13. Radioiodination of cyclin dependent kinase inhibitor Olomoucine loaded Fe rate at Au nanoparticle and evaluation of the therapeutic efficacy on cancerous cells

    International Nuclear Information System (INIS)

    Takan, Gokhan; Guldu, Ozge Kozgus; Medine, Emin Ilker

    2017-01-01

    Magnetic nanoparticles have promising biomedical applications such as drug delivery, novel therapeutics and diagnostic imaging. Magnetic drug delivery combination works on the delivery of magnetic nanoparticles loaded with drug to the target tissue by means of an external magnetic field. Gold coated iron oxide (Fe rate at Au) nanoparticles can provide useful surface chemistry and biological reactivity. Covalent conjugation to the Fe rate at Au nanoparticles through cleavable linkages can be used to deliver drugs to tumor cells, then the drug can be released by an external. In this paper, purine based cyclin dependent kinases (CDKs) inhibitor Olomoucine (Olo) [2-(Hydroxyethylamino)-6-benzylamino-9-methylpurine] was loaded on gold coated iron oxide (Fe rate at Au) nanoparticles and radiolabeled with "1"3"1I to combine magnetic targeted drug delivery and radiotherapy. Fe rate at Au nanoparticles were synthesized by microemulsion method. The characterization of nanoparticles was examined by TEM, VSM and XRD. Amine activation was utilized by cysteamine hydrochloride and then CDI was used for conjugation of Olomoucine. Antiproliferative effect and cytotoxicity of Olomoucine loaded Fe rate at Au nanoparticles (Fe rate at Au-Olo) were investigated on MCF7 and A549 cell lines. Proliferation rate was decreased while uptake of Fe rate at Au-Olo on both cell lines was high in comparison with Olomoucine. Also, enhanced incorporation ratio was observed under external magnetic field.

  14. Radiation synthesized protein-based nanoparticles: A technique overview

    International Nuclear Information System (INIS)

    Varca, Gustavo H.C.; Perossi, Gabriela G.; Grasselli, Mariano; Lugão, Ademar B.

    2014-01-01

    Seeking for alternative routes for protein engineering a novel technique – radiation induced synthesis of protein nanoparticles – to achieve size controlled particles with preserved bioactivity has been recently reported. This work aimed to evaluate different process conditions to optimize and provide an overview of the technique using γ-irradiation. Papain was used as model protease and the samples were irradiated in a gamma cell irradiator in phosphate buffer (pH=7.0) containing ethanol (0–35%). The dose effect was evaluated by exposure to distinct γ-irradiation doses (2.5, 5, 7.5 and 10 kGy) and scale up experiments involving distinct protein concentrations (12.5–50 mg mL −1 ) were also performed. Characterization involved size monitoring using dynamic light scattering. Bityrosine detection was performed using fluorescence measurements in order to provide experimental evidence of the mechanism involved. Best dose effects were achieved at 10 kGy with regard to size and no relevant changes were observed as a function of papain concentration, highlighting very broad operational concentration range. Bityrosine changes were identified for the samples as a function of the process confirming that such linkages play an important role in the nanoparticle formation. - Highlights: • Synthesis of protein-based nanoparticles by γ-irradiation. • Optimization of the technique. • Overview of mechanism involved in the nanoparticle formation. • Engineered papain nanoparticles for biomedical applications

  15. From core/shell to hollow Fe/γ-Fe_2O_3 nanoparticles: evolution of the magnetic behavior

    International Nuclear Information System (INIS)

    Nemati, Z; Khurshid, H; Alonso, J; Phan, M H; Mukherjee, P; Srikanth, H

    2015-01-01

    High quality Fe/γ-Fe_2O_3 core/shell, core/void/shell, and hollow nanoparticles with two different sizes of 8 and 12 nm were synthesized, and the effect of morphology, surface and finite-size effects on their magnetic properties including the exchange bias (EB) effect were systematically investigated. We find a general trend for both systems that as the morphology changes from core/shell to core/void/shell, the magnetization of the system decays and inter-particle interactions become weaker, while the effective anisotropy and the EB effect increase. The changes are more drastic when the nanoparticles become completely hollow. Noticeably, the morphological change from core/shell to hollow increases the mean blocking temperature for the 12 nm particles but decreases for the 8 nm particles. The low-temperature magnetic behavior of the 12 nm particles changes from a collective super-spin-glass system mediated by dipolar interactions for the core/shell nanoparticles to a frustrated cluster glass-like state for the shell nanograins in the hollow morphology. On the other hand for the 8 nm nanoparticles core/shell and hollow particles the magnetic behavior is more similar, and a conventional spin glass-like transition is obtained at low temperatures. In the case of the hollow nanoparticles, the coupling between the inner and outer spin layers in the shell gives rise to an enhanced EB effect, which increases with increasing shell thickness. This indicates that the morphology of the shell plays a crucial role in this kind of exchange-biased systems. (paper)

  16. Effect of alkaline earth metal doping on thermal, optical, magnetic and dielectric properties of BiFeO3 nanoparticles

    International Nuclear Information System (INIS)

    Bhushan, B; Das, D; Basumallick, A; Bandopadhyay, S K; Vasanthacharya, N Y

    2009-01-01

    Substrate-free pure-phase BiFeO 3 (BFO) nanoparticles doped with alkaline earth metals (Ba, Sr and Ca) have been synthesized by a sol-gel route and their thermal, optical, dielectric and magnetic properties are discussed. The characteristic structural phase transitions of BFO nanoparticles are found to occur at much lower temperatures. A reduction of the Neel temperature has been observed in the doped samples in comparison with the pristine one, whereas the band gap shows a reverse trend. Iron was found to be only in the Fe 3+ valence state in all the doped samples. Magnetoelectric coupling is seen in our samples. Weak ferromagnetism is observed at room temperature in all of the doped and undoped BFO nanoparticles with the largest value of coercive field ∼1.78 kOe and saturation magnetization ∼2.38 emu g -1 for Ba and Ca doped BFO nanoparticles, respectively.

  17. Floral Biosynthesis of Mn3O4 and Fe2O3 Nanoparticles Using Chaenomeles sp. Flower Extracts for Efficient Medicinal Applications

    Science.gov (United States)

    Karunakaran, Gopalu; Jagathambal, Matheswaran; Kolesnikov, Evgeny; Dmitry, Arkhipov; Ishteev, Artur; Gusev, Alexander; Kuznetsov, Denis

    2017-08-01

    Manganese oxide (Mn3O4) and iron oxide (Fe2O3) nanoparticles were successfully synthesized with the flower extracts of Chaenomeles sp. This is the first ever approach to synthesize nanoparticles from Chaenomeles sp. flower extracts. The organic molecules present in the flower extracts actively converted the nitrate precursor into its corresponding nanoparticles. The organic molecules that are involved in the synthesis of nanoparticles are identified using different phytochemical and gas chromatography-mass spectrometry analyses. The identified components are glycosides, alkaloids, terpenoids, saponins, flavonoids, quinines, and steroids. The structural and chemical compositions of the synthesized powder were also analyzed. The x-ray powder diffraction analysis revealed that the particles show tetragonal and rhombohedral crystalline phases. The Fourier transform infrared spectroscopy analysis showed the functional groups that are involved in the reduction of nitrates into the corresponding nanoparticles. Energy-dispersive x-ray spectroscopy analysis confirmed the presence of the elements in the synthesized nanoparticles. Transmission electron microscopy images showed the formation of spherical nanoparticles with an average size of 30-100 nm. Antioxidant analysis showed that the synthesized nanoparticles had excellent antioxidant potential. The antibacterial study showed that they inhibit the growth of harmful bacteria such as Pseudomonas aeruginosa and Streptococcus pyogenes. Thus, this study proposes a new eco-friendly and nontoxic method to synthesize nanoparticles for medicinal applications.

  18. Nonequilibrium dynamics in an interacting Fe-C nanoparticle system

    DEFF Research Database (Denmark)

    Jönsson, P.; Hansen, Mikkel Fougt; Nordblad, P.

    2000-01-01

    Nonequilibrium dynamics in an interacting Fe-C nanoparticle sample, exhibiting a low-temperature spin-glass-like phase, has been studied by low-frequency ac susceptibility and magnetic relaxation experiments. The nonequilibrium behavior shows characteristic spin-glass features, but some qualitative...

  19. Room temperature ferromagnetism in Fe-doped CeO2 nanoparticles.

    Science.gov (United States)

    Maensiri, Santi; Phokha, Sumalin; Laokul, Paveena; Seraphin, Supapan

    2009-11-01

    RT ferromagnetism was observed in nanoparticles of Fe-doped CeO2 (i.e., Ce(0.97)Fe(0.03)O2) synthesized by a sol-gel method. The undoped and Fe-doped CeO2 were characterized by XRD, Raman spectroscopy, TEM, and VSM. The undoped samples and Ce(0.97)Fe(0.03)O2 precursor exhibit a diamagnetic behavior. The 673 K-calcined Ce(0.97)Fe(0.03)O2 sample is paramagnetic whereas 773 and 873 K-calcined Ce(0.97)Fe(0.03)O2 samples are ferromagnetism having the magnetizations of 4.65 x 10(-3) emu/g and 6.20 x 10(-3) emu/g at 10 kOe, respectively. Our results indicate that the ferromagnetic property is intrinsic to the Fe-doped CeO2 system and is not a result of any secondary magnetic phase or cluster formation.

  20. Development of amperometric L-tyrosine sensor based on Fe-doped hydroxyapatite nanoparticles

    International Nuclear Information System (INIS)

    Kanchana, P.; Lavanya, N.; Sekar, C.

    2014-01-01

    A novel biosensor based on Fe-doped hydroxyapatite (Fe-HA) nanoparticles and tyrosinase has been developed for the detection of L-tyrosine. Nanostructured Fe-HA was synthesized by a simple microwave irradiation method, and its phase formation, morphology and magnetic property were examined by powder X-ray diffraction (XRD), transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM). Electrochemical performance of the nano Fe-HA/tyrosinase modified glassy carbon electrode (GCE) for detection of L-tyrosine was investigated by cyclic voltammetry (CV) and amperometric methods. The fabricated biosensor exhibited a linear response to L-tyrosine over a wide concentration range of 1.0 × 10 −7 to 1.0 × 10 −5 M with a detection limit of 245 nM at pH 7.0. In addition, the fabricated sensor showed an excellent selectivity, good reproducibility, long-term stability and anti-interference towards the determination of L-tyrosine. - Highlights: • A novel amperometric L-tyrosine biosensor has been fabricated using nanostructured Fe-HA. • The fabricated sensor exhibits a wide linear range, good stability and high reproducibility. • Fe-HA assists microenvironment and direct electron transfer between enzyme and electrode surface. • The nano Fe-HA and electrode fabrication procedure are simple and less expensive

  1. Effect of hydrogen on the microstructure and electrochemical properties of Si nanoparticles synthesized by microwave plasma

    Energy Technology Data Exchange (ETDEWEB)

    Koo, Jeongboon; Lee, Jeongeun; Kim, Joonsoo; Jang, Boyun, E-mail: byjang@kier.re.kr

    2016-09-01

    We synthesized silicon (Si) nanoparticles using an atmospheric microwave plasma process, and investigated the effects of hydrogen (H{sub 2}) injection on their microstructure during the synthesis. Two nozzles were applied to inject H{sub 2} (swirling and rectilinear H{sub 2}). Our microstructural analysis indicated that the amount and method of H{sub 2} injection were critical for completion of the reaction from silicon tetrachloride (SiCl{sub 4}) to Si, as well as to obtain highly crystalline Si nanoparticles. The swirling H{sub 2} was especially critical due to its formation of vortex flow, which allowed relatively long residence time of the H-ions in plasma. The Si nanoparticles synthesized by the atmospheric plasma process had core-shell structures that consisted of crystalline Si cores with amorphous SiO{sub x} shells of 5–15 nm thickness. We also investigated the feasibility of the synthesized Si nanoparticles as anode materials in a lithium-ion battery (LIB). For the core-shell structured Si nanoparticles, we obtained the first reversible capacity of 1204 mAhg{sup −1}, and a capacity retention of 82.2% at the 50{sup th} cycle. - Highlights: • We synthesized Si nanoparticles by an atmospheric microwave plasma process. • We investigated the effects of injected H{sub 2} on the microstructures of Si nanoparticles. • Swirling H{sub 2} was critical, due to the formation of vortex flow in plasma. • The synthesized Si nanoparticles had core (crystalline Si)-shell (SiO{sub x}) structures. • The electrochemical properties depend on its core-shell structures as LIB anode.

  2. Synthesis and characterization of La(Cr,Fe,Mn)O{sub 3} nanoparticles obtained by co-precipitation method

    Energy Technology Data Exchange (ETDEWEB)

    Fabian, F.A., E-mail: fernandafabianro@gmail.com [Universidade Federal de Sergipe, Campus Prof. Aluísio Campos, Departamento de Física, 49100-000 São Cristóvão, SE (Brazil); Pedra, P.P.; Filho, J.L.S. [Universidade Federal de Sergipe, Campus Prof. Aluísio Campos, Departamento de Física, 49100-000 São Cristóvão, SE (Brazil); Duque, J.G.S.; Meneses, C.T. [Universidade Federal de Sergipe, Campus Prof. Alberto Carvalho, Departamento de Física, 49500-000 Itabaiana, SE (Brazil)

    2015-04-01

    Magnetic and structural properties have been investigated in La(Cr,Fe,Mn)O{sub 3} nanoparticles obtained by co-precipitation method. The X-ray diffraction measurements allied to Rietveld method confirm the formation of LaCrO{sub 3}, LaFeO{sub 3} and LaMnO{sub 3} nanoparticles with crystal structure orthorhombic (Pbnm), orthorhombic (Pnma) and rhombohedral (R-3c), respectively. We also verified an decreasing in the average crystallite size from 73 to 26 nm, depending of the transition metal. The magnetic measurements reveal an antiferromagnetic behavior for the LaCrO{sub 3} sample with T{sub N}~289 K, and a weak ferromagnetic ordering for the LaMnO{sub 3} sample with T{sub c}~200 K. - Highlights: • La(Cr,Fe,Mn)O{sub 3} nanoparticles were synthesized by coprecipitation method. • XRD results confirm the formation single phase in the compounds studied. • Magnetic property in the La(Fe,Cr,Mn)O{sub 3} nanoparticles dependent on the TM. • La(Cr,Fe)O{sub 3} nanoparticles presented behavior antiferromagnetic and LaMnO{sub 3} ferromagnetic.

  3. Cytotoxic effect of nanoparticles synthesized from Salvia officinalis L ...

    African Journals Online (AJOL)

    The development of safe carriers for the use of plant extracts in industrial and health fields constitute a matter of serious concern. The development of plant derived nanoparticles may help to overcome such barriers. However, the major concern is still the safety of these carriers. The present study describes the synthesis of ...

  4. Nanoparticles of complex metal oxides synthesized using the ...

    Indian Academy of Sciences (India)

    ASHOK K GANGULI∗, TOKEER AHMAD, PADAM R ARYA and PIKA JHA ... nanoparticles of several dielectric oxides like BaTiO3, Ba2TiO4, SrTiO3, PbTiO3 .... reasonable stability till 150◦C. All the lead-doped phases (sintered at 900◦C) show.

  5. Structural, morphological and dielectric studies of zirconium substituted CoFe2O4 nanoparticles

    Directory of Open Access Journals (Sweden)

    S. Anand

    2017-12-01

    Full Text Available In this work, the influence of zirconium substitution in cubic spinel nanocrystalline CoFe2O4 on the structural, morphological and dielectric properties are reported. Zirconium substituted cobalt ferrite Co1-xZrxFe2O4 (x = 0.7 nanoparticles were synthesized by sol-gel route. The structural and morphological investigations using powder X-ray diffraction and high resolution scanning electron microscope (HRSEM analysis are reported. Scherrer plot, Williamson–Hall analysis and Size-strain plot method were used to calculate the crystallite size and lattice strain of the samples. High purity chemical composition of the sample was confirmed by energy dispersive X-ray analysis. The atoms vibration modes of as synthesized nanoparticles were recorded using Fourier transform infrared (FTIR spectrometer in the range of 4000–400 cm-1. The temperature-dependent dielectric properties of zirconium substituted cobalt ferrite nanoparticles were also carried out. Relative dielectric permittivity, loss tangent and AC conductivity were measured in the frequency range 50 Hz to 5 MHz at temperatures between 323 K and 473 K. The dielectric constant and dielectric loss values of the sample decreased with increasing in the frequency of the applied signal.

  6. Facilely synthesized Fe{sub 2}O{sub 3}–graphene nanocomposite as novel electrode materials for supercapacitors with high performance

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Zhuo; Ma, Chunyan; Wang, Hailin [Department of Environmental Nano-Materials, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Liu, Zonghuai [Key Laboratory of Applied Surface and Colloid Chemistry (Shaanxi Normal University), Ministry of Education, Xi’an 710062 (China); School of Materials Science and Engineering, Shaanxi Normal University, Xi’an 710062 (China); Hao, Zhengping, E-mail: zpinghao@rcees.ac.cn [Department of Environmental Nano-Materials, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China)

    2013-03-05

    Graphical abstract: Fe{sub 2}O{sub 3}Graphene nanocomposite was synthesized in a simple hydrothermal way by using urea to adjust the system pH value, by this method the reduction of graphite oxide and the formation of Fe{sub 2}O{sub 3} nanocomposite are finished in one step. The specific capacitance of the Fe{sub 2}O{sub 3}Graphene electrode reached 226 F/g at a discharge current density of 1 A g{sup –1}. Highlights: ► The Fe{sub 2}O{sub 3}–graphene nanocomposite was obtained by friendly method with urea in one step. ► The addition of Fe{sub 2}O{sub 3} composites has positive effect on the electrical performance of the graphene nanosheets. ► The specific capacitance of the Fe{sub 2}O{sub 3}–graphene electrode was 226 F/g at a discharge current density of 1 A g{sup −1}. -- Abstract: Fe{sub 2}O{sub 3}–graphene nanocomposite with high capacitive properties had been prepared friendly and facilely by hydrothermal method in one-step. The morphology and structure of the obtained material were examined by X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET) and transmission electron microscope (TEM) techniques. It was revealed by TEM images that Fe{sub 2}O{sub 3} nanoparticles grow well on the surface of graphene and the formation of Fe{sub 2}O{sub 3} nanoparticles hinders the aggregation of graphene (reduced graphene oxide, namely, RGO). Electrochemical properties of the synthesized materials were characterized by serials of electrochemical measurements in 1 M Na{sub 2}SO{sub 4} electrolyte. Fe{sub 2}O{sub 3}–graphene nanocomposite electrode show higher specific capacitance than graphene, indicating an accelerative effect of Fe{sub 2}O{sub 3} and graphene on improving the electrochemical performance of the electrode. The specific capacitance of Fe{sub 2}O{sub 3}–graphene nanocomposite is 226 F/g at a current density of 1 A/g. These attractive results indicate it is possible to seek and develop the promising, environmentally benign and commercial

  7. XAFS Studies of Fe Doped PhTiO3 Nanoparticles

    International Nuclear Information System (INIS)

    Shibata, Tomohiro; Chattopadhyay, Soma; Lin Bin; Palkar, V. R.

    2007-01-01

    Fe K and Ti K edge XAFS studies are reported on Fe doped PbTiO3 nanoparticles down to the 10 nm size. Fe forms Fe3+ ions and substitute for Ti4+ ions. For 18 nm nanoparticles, the Fe and Ti environment is found to be quite different. For PbFe0.5Ti0.5O3, locally the structure remains distorted from bulk to 10 nm size although the average structure changes

  8. Ferroelectric and magnetic properties in high-pressure synthesized BiFeO3 compound

    International Nuclear Information System (INIS)

    Zhai, L.; Shi, Y.G.; Gao, J.L.; Tang, S.L.; Du, Y.W.

    2011-01-01

    Highlights: → A high-density polycrystalline BiFeO 3 compound was synthesized by high-pressure annealing method. → The sample showed weak ferromagnetic at room temperature, which could be attributed to the lattice distortion induced by the high-pressure annealing. → Irregular domains were observed on the surface of the sample by piezoresponse force microscopy, and a typical hysteresis loop was obtained. - Abstract: High-density polycrystalline BiFeO 3 compound was synthesized by high-pressure annealing. Measurements of crystal structure, magnetic, and ferroelectric properties were made on the sample. It was found that the sample was almost single phase with a distorted R3c structure. The results of the X-ray photoelectron spectra demonstrate that the oxidation state of Fe in the sample is Fe 3+ . The room-temperature field dependence of magnetization for BiFeO 3 exhibits a hysteretic behavior. The observed weak ferromagnetism could be ascribed to the lattice distortion induced by the high-pressure annealing. In addition, the local ferroelectric performance of the sample was studied by piezoresponse force microscopy.

  9. Study of Ag and Au Nanoparticles Synthesized by Arc Discharge in Deionized Water

    Directory of Open Access Journals (Sweden)

    Der-Chi Tien

    2010-01-01

    Full Text Available The paper presents a study of Ag and Au nanofluids synthesized by the arc discharge method (ADM in deionized water. The metallic Ag nanoparticle (Ag0 and ionic Ag (Ag+ have played an important role in the battle against germs which are becoming more drug-resistant every year. Our study indicates that Ag nanoparticle suspension (SNPS fabricated by using ADM without added surfactants exclusively contains the metallic Ag nanoparticle and ionic Ag. Besides that, the ADM in deionized water has also been employed for the fabrication process of Au nanoparticles. The experimental results indicate that the prepared Ag nanoparticles can react with the dissolved H2CO3 in deionized water, leading to the formation of Ag2CO3. Significantly different to Ag, the prepared Au nanoparticles with their surfaces bonded by oxygen are suspended in deionized water by the formation of hydrogen bonded with the neighboring water molecules.

  10. Structural and magnetic properties of cobalt ferrite nanoparticles synthesized by co-precipitation at increasing temperatures

    Science.gov (United States)

    Stein, C. R.; Bezerra, M. T. S.; Holanda, G. H. A.; André-Filho, J.; Morais, P. C.

    2018-05-01

    This study reports on the synthesis and characterization of cobalt ferrite (CoFe2O4) nanoparticles (NPs) synthesized by chemical co-precipitation in alkaline medium at increasing temperatures in the range of 27 °C to 100 °C. High-quality samples in the size range of 5 to 10 nm were produced using very low stirring speed (250 rpm) and moderate alkaline aqueous solution concentration (4.8 mol/L). Three samples were synthesized and characterized by x-ray diffraction (XRD) and room-temperature (RT) magnetization measurements. All samples present superparamagnetic (SPM) behavior at RT and Rietveld refinements confirm the inverse cubic spinel structure (space group Fd-3m (227)) with minor detectable impurity phase. As the synthesis temperature increases, structural parameters such as lattice constant and grain size change monotonically from 8.385 to 8.383 Å and from 5.8 to 7.4 nm, respectively. Likewise, as the synthesis temperature increases the NPs' magnetic moment and saturation magnetization increases monotonically from 2.6 ×103 to 16×103 μB and from 37 to 66 emu/g, respectively. The RT magnetization (M) versus applied field (H) curves were analyzed by the first-order Langevin function averaged out by a lognormal distribution function of magnetic moments. The excellent curve-fitting of the M versus H data is credited to a reduced particle-particle interaction due to both the SPM behavior and the existence of a surface amorphous shell layer (dead layer), the latter reducing systematically as the synthesis temperature increases.

  11. Photoluminescence quenching and enhanced spin relaxation in Fe doped ZnO nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Ovhal, Manoj M.; Santhosh Kumar, A. [Department of Materials Engineering, Defence Institute of Advanced Technology, Girinagar, Pune 411025 (India); Khullar, Prerna [School of Materials Science and Technology, Indian Institute of Technology (Banaras Hindu University), Varanasi 221005 (India); Kumar, Manjeet [Department of Materials Engineering, Defence Institute of Advanced Technology, Girinagar, Pune 411025 (India); Abhyankar, A.C., E-mail: ashutoshabhyankar@gmail.com [Department of Materials Engineering, Defence Institute of Advanced Technology, Girinagar, Pune 411025 (India)

    2017-07-01

    Cost-effective ultrasonically assisted precipitation method is utilized to synthesize Zinc oxide (ZnO) nanoparticles (NPs) at room temperature and the effect of Iron (Fe) doping on structural, optical and spin relaxation properties also presented. As-synthesized pure and Fe doped ZnO NPs possess a perfect hexagonal growth habit of wurtzite zinc oxide, along the (101) direction of preference. With Fe doping, ‘c/a’ ratio and compressive lattice strain in ZnO NPs are found to reduce and increase, respectively. Raman studies demonstrate that the E{sub 1} longitudinal optical (LO) vibrational mode is very weak in pure which remarkably enhanced with Fe doping into ZnO NPs. The direct band gap energy (E{sub g}) of the ZnO NPs has been increased from 3.02 eV to 3.11 eV with Fe doping. A slight red-shift observed with strong green emission band, in photoluminescence spectra, is strongly quenched in 6 wt.% Fe doped ZnO NPs. The field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) reveals spherical shape of ZnO NPs with 60–70 nm, which reduces substantially on Fe doping. The energy dispersive X-ray spectrum and elemental mapping confirms the homogeneous distribution of Fe in ZnO NPs. Moreover, the specific relaxation rate (R{sub 2sp} = 1/T{sub 2}) has been measured using Carr-Purcell-Meiboom-Gill (CPMG) method and found to be maximum in 6 wt.% Fe doped ZnO NPs. Further, the correlation of structural, optical and dynamic properties is proposed. - Highlights: • Pure ZnO and Fe doped ZnO NPs were successfully prepared by cost effective ultrasonically assisted precipitation method. • The optical band gap of ZnO has been enhanced form 3.02–3.11 eV with Fe doping. • PL quenching behaviour has been observed with Fe{sup 3+} ions substitution in ZnO lattice. • Specific relaxation rate (R{sub 2sp} = 1/T{sub 2}) has been varied with Fe doping and found to be maximum in 6 wt.% Fe doped ZnO NPs.

  12. Microwave-synthesized freestanding iron-carbon nanotubes on polyester composites of woven Kevlar fibre and silver nanoparticle-decorated graphene

    Science.gov (United States)

    Hazarika, Ankita; Deka, Biplab K.; Kim, DoYoung; Kong, Kyungil; Park, Young-Bin; Park, Hyung Wook

    2017-01-01

    We synthesized Ag nanoparticle-decorated multilayered graphene nanosheets (Ag-graphene) from graphite nanoplatelets and silver nitrate through 90–100 s of microwave exposure, without the use of any mineral acids or harsh reducing agents. Fe nanoparticle-decorated carbon nanotubes (Fe-CNTs) were grown on polypyrrole (PPy) deposited on woven Kevlar fibre (WKF), using ferrocene as a catalyst, under microwave irradiation. Fe-CNTs grown on WKF and Ag-graphene dispersed in polyester resin (PES) were combined to fabricate Ag-graphene/Fe-CNT/PPy-coated WKF/PES composites by vacuum-assisted resin transfer moulding. The combined effect of Fe-CNTs and Ag-graphene in the resulting composites resulted in a remarkable enhancement of tensile properties (a 192.56% increase in strength and 100.64% increase in modulus) as well as impact resistance (a 116.33% increase). The electrical conductivity significantly increased for Ag-graphene/Fe-CNT/PPy-coated WKF/PES composites. The effectiveness of electromagnetic interference shielding, which relies strongly on the Ag-graphene content in the composites, was 25 times higher in Ag-graphene/Fe-CNT/PPy-coated WKF/PES than in neat WKF/PES composites. The current work offers a novel route for fabricating highly promising, cost effective WKF/PES composites through microwave-assisted synthesis of Fe-CNTs and Ag-graphene. PMID:28074877

  13. Microwave-synthesized freestanding iron-carbon nanotubes on polyester composites of woven Kevlar fibre and silver nanoparticle-decorated graphene.

    Science.gov (United States)

    Hazarika, Ankita; Deka, Biplab K; Kim, DoYoung; Kong, Kyungil; Park, Young-Bin; Park, Hyung Wook

    2017-01-11

    We synthesized Ag nanoparticle-decorated multilayered graphene nanosheets (Ag-graphene) from graphite nanoplatelets and silver nitrate through 90-100 s of microwave exposure, without the use of any mineral acids or harsh reducing agents. Fe nanoparticle-decorated carbon nanotubes (Fe-CNTs) were grown on polypyrrole (PPy) deposited on woven Kevlar fibre (WKF), using ferrocene as a catalyst, under microwave irradiation. Fe-CNTs grown on WKF and Ag-graphene dispersed in polyester resin (PES) were combined to fabricate Ag-graphene/Fe-CNT/PPy-coated WKF/PES composites by vacuum-assisted resin transfer moulding. The combined effect of Fe-CNTs and Ag-graphene in the resulting composites resulted in a remarkable enhancement of tensile properties (a 192.56% increase in strength and 100.64% increase in modulus) as well as impact resistance (a 116.33% increase). The electrical conductivity significantly increased for Ag-graphene/Fe-CNT/PPy-coated WKF/PES composites. The effectiveness of electromagnetic interference shielding, which relies strongly on the Ag-graphene content in the composites, was 25 times higher in Ag-graphene/Fe-CNT/PPy-coated WKF/PES than in neat WKF/PES composites. The current work offers a novel route for fabricating highly promising, cost effective WKF/PES composites through microwave-assisted synthesis of Fe-CNTs and Ag-graphene.

  14. Microwave-synthesized freestanding iron-carbon nanotubes on polyester composites of woven Kevlar fibre and silver nanoparticle-decorated graphene

    Science.gov (United States)

    Hazarika, Ankita; Deka, Biplab K.; Kim, Doyoung; Kong, Kyungil; Park, Young-Bin; Park, Hyung Wook

    2017-01-01

    We synthesized Ag nanoparticle-decorated multilayered graphene nanosheets (Ag-graphene) from graphite nanoplatelets and silver nitrate through 90-100 s of microwave exposure, without the use of any mineral acids or harsh reducing agents. Fe nanoparticle-decorated carbon nanotubes (Fe-CNTs) were grown on polypyrrole (PPy) deposited on woven Kevlar fibre (WKF), using ferrocene as a catalyst, under microwave irradiation. Fe-CNTs grown on WKF and Ag-graphene dispersed in polyester resin (PES) were combined to fabricate Ag-graphene/Fe-CNT/PPy-coated WKF/PES composites by vacuum-assisted resin transfer moulding. The combined effect of Fe-CNTs and Ag-graphene in the resulting composites resulted in a remarkable enhancement of tensile properties (a 192.56% increase in strength and 100.64% increase in modulus) as well as impact resistance (a 116.33% increase). The electrical conductivity significantly increased for Ag-graphene/Fe-CNT/PPy-coated WKF/PES composites. The effectiveness of electromagnetic interference shielding, which relies strongly on the Ag-graphene content in the composites, was 25 times higher in Ag-graphene/Fe-CNT/PPy-coated WKF/PES than in neat WKF/PES composites. The current work offers a novel route for fabricating highly promising, cost effective WKF/PES composites through microwave-assisted synthesis of Fe-CNTs and Ag-graphene.

  15. Optical and Magnetic Properties of Fe Doped ZnO Nanoparticles Obtained by Hydrothermal Synthesis

    Directory of Open Access Journals (Sweden)

    Xiaojuan Wu

    2014-01-01

    Full Text Available Diluted magnetic semiconductors Zn1-xFexO nanoparticles with different doping concentration (x=0, 0.01, 0.05, 0.10, and 0.20 were successfully synthesized by hydrothermal method. The crystal structure, morphology, and optical and magnetic properties of the samples were characterized by X-ray diffraction (XRD, energy dispersive spectrometer (EDS, high-resolution transmission electron microscopy (HRTEM, Raman scattering spectra (Raman, photoluminescence spectra (PL, and the vibrating sample magnetometer (VSM. The experiment results show that all samples synthesized by this method possess hexagonal wurtzite crystal structure with good crystallization, no other impurity phases are observed, and the morphology of the sample shows the presence of ellipsoidal nanoparticles. All the Fe3+ successfully substituted for the lattice site of Zn2+ and generates single-phase Zn1-xFexO. Raman spectra shows that the peak shifts to higher frequency. PL spectra exhibit a slight blue shift and the UV emission is annihilated with the increase of Fe3+ concentration. Magnetic measurements indicated that Fe-doped ZnO samples exhibit ferromagnetic behavior at room temperature and the saturation magnetization is enhanced with the increase of iron doping content.

  16. Structural, magnetic, and electrical properties of Gd-doped BiFeO3 nanoparticles with reduced particle size

    International Nuclear Information System (INIS)

    Lotey, Gurmeet Singh; Verma, N. K.

    2012-01-01

    Pure and Gd-doped BiFeO 3 nanoparticles have been synthesized by sol–gel method. The significant effects of size and Gd-doping on structural, electrical, and magnetic properties have been investigated. X-ray diffraction study reveals that the pure BiFeO 3 nanoparticles possess rhombohedral structure, but with 10% Gd-doping complete structural transformation from rhombohedral to orthorhombic has been observed. The particle size of pure and Gd-doped BiFeO 3 nanoparticles, calculated using Transmission electron microscopy, has been found to be in the range 25–15 nm. Pure and Gd-doped BiFeO 3 nanoparticles show ferromagnetic character, and the magnetization increases with decrease in particle size and increase in doping concentration. Scanning electron microscopy study reveals that grain size decreases with increase in Gd concentration. Well-saturated polarization versus electric field loop is observed for the doped samples. Leakage current density decreases by four orders by doping Gd in BiFeO 3 . The incorporation of Gd in BiFeO 3 enhances spin as well as electric polarization at room temperature. The possible origin of enhancement in these properties has been explained on the basis of dopant and its concentration, phase purity, small particle, and grain size.

  17. Effect of Fe3O4 Nanoparticles on Skin Tumor Cells and Dermal Fibroblasts

    Directory of Open Access Journals (Sweden)

    Lirija Alili

    2015-01-01

    Full Text Available Iron oxide (Fe3O4 nanoparticles have been used in many biomedical approaches. The toxicity of Fe3O4 nanoparticles on mammalian cells was published recently. Though, little is known about the viability of human cells after treatment with Fe3O4 nanoparticles. Herein, we examined the toxicity, production of reactive oxygen species, and invasive capacity after treatment of human dermal fibroblasts (HDF and cells of the squamous tumor cell line (SCL-1 with Fe3O4 nanoparticles. These nanoparticles had an average size of 65 nm. Fe3O4 nanoparticles induced oxidative stress via generation of reactive oxygen species (ROS and subsequent initiation of lipid peroxidation. Furthermore, the question was addressed of whether Fe3O4 nanoparticles affect myofibroblast formation, known to be involved in tumor invasion. Herein, Fe3O4 nanoparticles prevent the expression alpha-smooth muscle actin and therefore decrease the number of myofibroblastic cells. Moreover, our data show in vitro that concentrations of Fe3O4 nanoparticles, which are nontoxic for normal cells, partially reveal a ROS-triggered cytotoxic but also a pro-invasive effect on the fraction of squamous cancer cells surviving the treatment with Fe3O4 nanoparticles. The data herein show that the Fe3O4 nanoparticles appear not to be adequate for use in therapeutic approaches against cancer cells, in contrast to recently published data with cerium oxide nanoparticles.

  18. Effect of hydrophobic coating on the magnetic anisotropy and radiofrequency heating of γ-Fe2O3 nanoparticles

    International Nuclear Information System (INIS)

    Singh, Mandeep; Ulbrich, Pavel; Prokopec, Vadym; Svoboda, Pavel; Šantavá, Eva; Štěpánek, František

    2013-01-01

    The effect of a hydrophobic (oleic acid) coating on the magnetic properties of maghemite (γ-Fe 2 O 3 ) nanoparticles was investigated. The nanoparticles were prepared by a novel bi-phasic co-precipitation route and their properties compared with uncoated nanoparticles and nanoparticles prepared by a standard single-phase process. The oleic acid coated nanoparticles had a mean diameter of 6 nm when the two-phase precipitation procedure was used compared to 12 nm for nanoparticles prepared in a single phase under otherwise identical conditions. Super Quantum Interference Device measurements show superparamagnetism of the nanoparticles, with a saturation magnetization at 4 K to be 66.4 emu/g and 89.0 emu/g for the coated nanoparticles obtained by two- and single-phase procedure, respectively. Zero-field-cooled and field-cooled curves reveal a dramatic shift in the blocking temperature of the coated nanoparticles, and a significant change in their anisotropy. The hydrophobic nanoparticles were able to form stable ferrofluids in a range of organic solvents and show good heating rates in a 400 kHz alternating magnetic field. - Highlights: ► Hydrophobic iron oxide nanoparticles synthesized by a new microemulsion approach. ► Strong influence of oleic acid coating on blocking temperature observed. ► Stable non-aqueous ferrofluids prepared. ► Favorable heating rates under alternating magnetic field

  19. Ferromagnetic resonance on oxideless magnetic Fe and FeRh nanoparticles

    International Nuclear Information System (INIS)

    Trunova, Anastasia

    2009-01-01

    This work is dedicated to investigations of structural and magnetic properties of the colloidal Fe/Fe x O y nanocubes (13 nm) and the Fe x Rh 100-x core/shell nanoparticles (2 nm). As compared with other works, where the measurements on oxidized nanoparticles were carried out, we additionally performed investigations on nanoparticles in an oxide free state. In order to make the measurements on oxide free particles possible, oxygen- and hydrogenplasma was used to remove the ligands and reduce the oxide shell of the Fe nanocubes. The oxide free Fe nanocubes were covered with a Ag/Pt protective coating to prevent them from new oxidation. This method allowed carrying out the magnetic measurements on oxide free Fe nanocubes. Micromagnetic simulations as well as simulations of the high frequency susceptibility were used for the data analysing. It was found that both the g-factor g=2.09±0.01 and the anisotropy constant K 4 =(4.8±0.5).10 4 J/m 3 coincide with that of bulk iron. However, the saturation magnetization M S (5 K)=(1.2±0.12).10 6 A/m differs from the bulk value by 30%. The reduction by 30% compared to the bulk value in the case of nanoparticles may be caused by the following possible reasons: a) the presence of inner oxide layer (approx. 10 at.%) that cannot be reduced; b) the anti-parallel order between magnetic moments of iron core and magnetic moments of antiferomagnetic iron oxide; c) some structural changes of the surface after plasma treatment. The obtained damping parameter α=0.03±0.005 is ten times larger than that of the Fe layers as it is known for nanoparticles systems in general. The core/shell Fe x Rh 100-x nanoparticles (x=80,50) were produced under Ar-atmosphere and were sealed into a quartz tube to prevent oxidation. The analysis of g-factors shows that the value for the FePh nanoparticles with Fe-rich core is larger (g=2.08±0.01) than that for the nanoparticles with Rh-rich core and coincides within error bars with the g-factor of bulk

  20. Dielectric properties of CdS nanoparticles synthesized by soft ...

    Indian Academy of Sciences (India)

    If the field applied to the condenser is time-dependent (as in an alternating current), so ... tematically the dielectric properties of CdS synthesized by a soft chemical method .... The real parts of conductivity spectra can be explained by the power ...

  1. Syntheses and applications of periodic mesoporous organosilica nanoparticles

    KAUST Repository

    Croissant, Jonas G.

    2015-11-06

    Periodic Mesoporous Organosilica (PMO) nanomaterials are envisioned to be one of the most prolific subjects of research in the next decade. Similar to mesoporous silica nanoparticles (MSN), PMO nanoparticles (NPs) prepared from organo-bridged alkoxysilanes have tunable mesopores that could be utilized for many applications such as gas and molecule adsorption, catalysis, drug and gene delivery, electronics, and sensing; but unlike MSN, the diversity in chemical nature of the pore walls of such nanomaterials is theoretically unlimited. Thus, we expect that PMO NPs will attract considerable interest over the next decade. In this review, we will present a comprehensive overview of the synthetic strategies for the preparation of nanoscaled PMO materials, and then describe their applications in catalysis and nanomedicine. The remarkable assets of the PMO structure are also detailed, and insights are provided for the preparation of more complex PMO nanoplatforms.

  2. Electrocatalysis of chemically synthesized noble metal nanoparticles on carbon electrodes

    DEFF Research Database (Denmark)

    Zhang, Ling; Ulstrup, Jens; Zhang, Jingdong

    Noble metal nanoparticles (NPs), such as platinum (Pt) and palladium (Pd) NPs are promising catalysts for dioxygen reduction and oxidation of molecules such as formic acid and ethanol in fuel cells. Carbon nanomaterials are ideal supporting materials for electrochemical catalysts due to their good...... by electrochemical SPM. This study offers promise for development of new high-efficiency catalyst types with low-cost for fuel cell technology...

  3. Radio-synthesized protein-based nanoparticles for biomedical purposes

    International Nuclear Information System (INIS)

    Varca, Gustavo H.C.; Ferraz, Caroline C.; Lopes, Patricia S.; Mathor, Monica beatriz; Grasselli, Mariano; Lugão, Ademar B.

    2014-01-01

    Protein-crosslinking whether done by enzymatic or chemically induced pathways increases the overall stability of proteins. In the continuous search for alternative routes for protein stabilization we report a novel technique – radio-induced synthesis of protein nanoparticles – to achieve size controlled particles with preserved bioactivity. Papain was used as model enzyme and the samples were irradiated at 10 kGy in a gammacell irradiator in phosphate buffer (pH=7.0) and additives such as ethanol (0–40%) and sodium chloride (0–25%). The structural rearrangement caused by irradiation under defined conditions led to an increase in papain particle size as a function of the additive and its concentration. These changes occur due to intermolecular bindings, of covalent nature, possibly involving the aromatic amino acids. Ethanol held major effects over papain particle size and particle size distribution if compared to sodium chloride. The particles presented relative retained bioactivity and the physic-chemical characterization revealed similar fluorescence spectra indicating preserved conformation. Differences in fluorescence units were observed according to the additive and its concentration, as a result of protein content changes. Therefore, under optimized conditions, the developed technique may be applied for enzyme nanoparticles formation of controllable size and preserved bioactivity. Highlights: • Novel technique for the development of protein nanoparticles using γ-irradiation. • Size control of papain particles with preserved conformation and bioactivity. • Alternative method for controlled protein crosslinking. • Bioactive protein nanoparticles of biotechnological and clinical interest. • Protein-based drug carrier potential of biotechnological and clinical interest

  4. Bactericidal Efficiency of Silver Nanoparticles Synthesized from Annona squamosa

    Science.gov (United States)

    Jayavardhanan, R.; Nanda, Anima

    2016-09-01

    Nanotechnology is described as an emerging technology that not only holds promise for society, but also is capable of providing novel approaches to overcome our common problems. The present study focused on the synthesis of silver nanoparticles using the metabolites of Annona squamosa seeds. The biological reduction procedure proposed in this method was considered as better one compared to chemical mediated reduction methods. The advantages include nontoxic to the environment, less energy consuming and highly suitable for further biological applications. The seeds were separated from the fruit pulp, grinded into powder and dissolved in distilled water. The suspension was used as reducing agent and treated with silver nitrate at the concentration of 1mM. The reduction reaction was continuously monitored by UV-visible photo spectrometer. Further the samples were subjected to AFM, SEM and XRD analysis for the confirmation of their size, structure, agglomerations and the arrangements of crystals. Finally the antibacterial properties of nanoparticles were tested against clinically important pathogenic microorganisms using disc diffusion method and compared with the activities of standard antibiotics. The combinational effects of nanoparticles with commercial antibiotics also were tested by the same method.

  5. The effect of biologically and chemically synthesized silver nanoparticles (AgNPs) on biofilm formation

    Science.gov (United States)

    Chojniak, Joanna; Biedroń, Izabela; Mendrek, Barbara; Płaza, Grażyna

    2017-11-01

    Bionanotechnology has emerged up as integration between biotechnology and nanotechnology for developing biosynthetic and environmental-friendly technology for synthesis of nanomaterials. Different types of nanomaterials like copper, zinc, titanium, magnesium, gold, and silver have applied in the various industries but silver nanoparticles have proved to be most effective against bacteria, viruses and eukaryotic microorganisms. The antimicrobial property of silver nanoparticles are widely known. Due to strong antibacterial property silver nanoparticles are used, e.g. in clothing, food industry, sunscreens, cosmetics and many household and environmental appliances. The aim of the study was to compare the effect of silver nanoparticles (AgNPs) synthesized biologically and chemically on the biofilm formation. The biofilm was formed by the bacteria isolated from the water supply network. The commonly used crystal violet assay (CV) was applied for biofilm analysis. In this study effect of biologically synthesized Ag-NPs on the biofilm formation was evaluated.

  6. Uncapped silver nanoparticles synthesized by DC arc thermal plasma technique for conductor paste formulation

    Science.gov (United States)

    Shinde, Manish; Pawar, Amol; Karmakar, Soumen; Seth, Tanay; Raut, Varsha; Rane, Sunit; Bhoraskar, Sudha; Amalnerkar, Dinesh

    2009-11-01

    Uncapped silver nanoparticles were synthesized by DC arc thermal plasma technique. The synthesized nanoparticles were structurally cubic and showed wide particle size variation (between 20-150 nm). Thick film paste formulated from such uncapped silver nanoparticles was screen-printed on alumina substrates and the resultant `green' films were fired at different firing temperatures. The films fired at 600 °C revealed better microstructure properties and also yielded the lowest value of sheet resistance in comparison to those corresponding to conventional peak firing temperature of 850 °C. Our findings directly support the role of silver nanoparticles in substantially depressing the operative peak firing temperature involved in traditional conductor thick films technology.

  7. Role of Cu During Sintering of Fe0.96Cu0.04 Nanoparticles

    Science.gov (United States)

    Sivaprahasam, D.; Sriramamurthy, A. M.; Bysakh, S.; Sundararajan, G.; Chattopadhyay, K.

    2018-04-01

    Nanoparticle agglomerates of passivated Fe ( n-Fe) and Fe0.96Cu0.04 ( n-Fe0.96Cu0.04), synthesized through the levitational gas condensation (LGC) process, were compacted and sintered using the conventional powder metallurgy method. The n-Fe0.96Cu0.04 agglomerates produced lower green density than n-Fe, and when compacted under pressure beyond 200 MPa, they underwent lateral cracking during ejection attributed to the presence of a passive oxide layer. Sintering under dynamic hydrogen atmosphere can produce a higher density of compact in n-Fe0.96Cu0.04 in comparison to n-Fe. Both the results of dilatometry and thermogravimetric (TG) measurements of the samples under flowing hydrogen revealed enhancement of the sintering process as soon as the reduction of oxide layers could be accomplished. The shrinkage rate of n-Fe0.96Cu0.04 reached a value three times higher than n-Fe at a low temperature of 723 K (450 °C) during heating. This enhanced shrinkage rate was the manifestation of accumulation of Cu at the surface of the particles. The formation of a thin-surface melted layer enriched with copper during heating to isothermal holding facilitated as a medium of transport for diffusion of the elements. The compacts produced by sintering at 773 K (500 °C), with relative density 82 pct, were found to be unstable and oxidized instantly when exposed to ambient atmosphere. The stable compacts of density more than 92 pct with 300- to 450-nm grain size could only be produced when sintering was carried out at 973 K (700 °C) and beyond. The 0.22 wt pct residual oxygen obtained in the sintered compact is similar to what is used for conventional ferrous powder metallurgy products.

  8. Lightweight reduced graphene oxide-Fe3O4 nanoparticle composite in the quest for an excellent electromagnetic interference shielding material

    Science.gov (United States)

    Singh, Ashwani Kumar; Kumar, Ajit; Kamal Haldar, Krishna; Gupta, Vinay; Singh, Kedar

    2018-06-01

    This work reports a detailed study of reduced graphene oxide (rGO)-Fe3O4 nanoparticle composite as an excellent electromagnetic (EM) interference shielding material in GHz range. A rGO-Fe3O4 nanoparticle composite was synthesized using a facile, one step, and modified solvothermal method with the reaction of FeCl3, ethylenediamine and graphite oxide powder in the presence of ethylene glycol. Various structural, microstructural and optical characterization tools were used to determine its synthesis and various properties. Dielectric, magnetic and EM shielding parameters were also evaluated to estimate its performance as a shielding material for EM waves. X-ray diffraction patterns have provided information about the structural and crystallographic properties of the as-synthesized material. Scanning electron microscopy micrographs revealed the information regarding the exfoliation of graphite into rGO. Well-dispersed Fe3O4 nanoparticles over the surface of the graphene can easily be seen by employing transmission electron microscopy. For comparison, rGO nanosheets and Fe3O4 nanoparticles have also been synthesized and characterized in a similar fashion. A plot of the dielectric and magnetic characterizations provides some useful information related to various losses and the relaxation process. Shielding effectiveness due to reflection (SER), shielding effectiveness due to absorption (SEA), and total shielding effectiveness (SET) were also plotted against frequency over a broad range (8–12 GHz). A significant change in all parameters (SEA value from 5 dB to 35 dB for Fe3O4 nanoparticles to rGO-Fe3O4 nanoparticle composite) was found. An actual shielding effectiveness (SET) up to 55 dB was found in the rGO-Fe3O4 nanoparticle composite. These graphs give glimpses of how significantly this material shows shielding effectiveness over a broad range of frequency.

  9. Lightweight reduced graphene oxide-Fe3O4 nanoparticle composite in the quest for an excellent electromagnetic interference shielding material.

    Science.gov (United States)

    Singh, Ashwani Kumar; Kumar, Ajit; Haldar, Krishna Kamal; Gupta, Vinay; Singh, Kedar

    2018-06-15

    This work reports a detailed study of reduced graphene oxide (rGO)-Fe 3 O 4 nanoparticle composite as an excellent electromagnetic (EM) interference shielding material in GHz range. A rGO-Fe 3 O 4 nanoparticle composite was synthesized using a facile, one step, and modified solvothermal method with the reaction of FeCl 3 , ethylenediamine and graphite oxide powder in the presence of ethylene glycol. Various structural, microstructural and optical characterization tools were used to determine its synthesis and various properties. Dielectric, magnetic and EM shielding parameters were also evaluated to estimate its performance as a shielding material for EM waves. X-ray diffraction patterns have provided information about the structural and crystallographic properties of the as-synthesized material. Scanning electron microscopy micrographs revealed the information regarding the exfoliation of graphite into rGO. Well-dispersed Fe 3 O 4 nanoparticles over the surface of the graphene can easily be seen by employing transmission electron microscopy. For comparison, rGO nanosheets and Fe 3 O 4 nanoparticles have also been synthesized and characterized in a similar fashion. A plot of the dielectric and magnetic characterizations provides some useful information related to various losses and the relaxation process. Shielding effectiveness due to reflection (SE R ), shielding effectiveness due to absorption (SE A ), and total shielding effectiveness (SE T ) were also plotted against frequency over a broad range (8-12 GHz). A significant change in all parameters (SE A value from 5 dB to 35 dB for Fe 3 O 4 nanoparticles to rGO-Fe 3 O 4 nanoparticle composite) was found. An actual shielding effectiveness (SE T ) up to 55 dB was found in the rGO-Fe 3 O 4 nanoparticle composite. These graphs give glimpses of how significantly this material shows shielding effectiveness over a broad range of frequency.

  10. The effect of green synthesized gold nanoparticles on rice germination and roots

    Science.gov (United States)

    Tsi Ndeh, Nji; Maensiri, Santi; Maensiri, Duangkamol

    2017-09-01

    In this paper, gold nanoparticles were synthesized by means of a green approach with Tiliacora triandra leaf extracts under different conditions. No additional reducing or capping agents were employed. The gold nanoparticles were characterized using UV-visible spectrophotometry, transmission electron microscope, x-ray diffraction and Fourier transform infrared spectroscopy. Gold nanoparticles synthesized at temperature of 80 °C were further used to treat rice (Oryza sativa) grains at different concentrations (0, 10, 100, 500, 1000, 2000 mg l-1) for one week. While germination percentages were high (95-98.38%), a slight decrease in root and shoot lengths relative to the control was observed. Phytotoxicity results indicated that the plant synthesized gold nanoparticles were of minimal toxicity to rice seedlings. Increases in cell death, hydrogen peroxide formation and lipid peroxidation in roots and shoots were noted. However, these increases were not statistically significant. The overall results confirmed that Tiliacora triandra synthesized gold nanoparticles are biocompatible and can be potentially used as nanocarriers in agriculture. Contribution at 5th Thailand International Nanotechnology Conference (Nano Thailand-2016), 27-29 November 2016, Nakhon Ratchasima, Thailand.

  11. Specific features of ZnCdS nanoparticles synthesized in different solvents

    Energy Technology Data Exchange (ETDEWEB)

    Kyazym-zade, A. G.; Jafarov, M. A., E-mail: maarif.jafarov@mail.ru; Nasirov, E. F.; Jahangirova, C. A.; Jafarli, R. S. [Baku State University (Azerbaijan)

    2017-04-15

    Stable colloidal solutions of ZnCdS nanoparticles (3–6 nm in diameter) in polyvinyl alcohol, polyethylene glycol, and H{sub 2}O are produced. The size of the synthesized nanoparticles is independent of the relation between precursors. It is shown that stabilization of the particles is defined by the charge-stability factor and can be attained without any additional stabilizing additives. The ZnCdS quantum dots synthesized emit in a wide spectral range from 450 to 600 nm.

  12. Synthesis and anomalous magnetic properties of LaFeO{sub 3} nanoparticles by hot soap method

    Energy Technology Data Exchange (ETDEWEB)

    Fujii, Tatsuo, E-mail: tfujii@cc.okayama-u.ac.jp [Department of Applied Chemistry, Okayama University, Tsushima-naka 3-1-1, Okayama 700-8530 (Japan); Matsusue, Ikkoh; Nakatsuka, Daisuke; Nakanishi, Makoto; Takada, Jun [Department of Applied Chemistry, Okayama University, Tsushima-naka 3-1-1, Okayama 700-8530 (Japan)

    2011-10-03

    Highlights: {yields} Nanocrystalline LaFeO{sub 3} particles were synthesized by using hot soap technique. {yields} Average diameter of the obtained LaFeO{sub 3} nanoparticles was about 15 nm. {yields} They exhibited superparamagnetic behavior with a blocking temperature of 30 K. {yields} Large magnetization due to the presence of uncompensated surface spins was induced. - Abstract: Nanocrystalline LaFeO{sub 3} particles were synthesized at low temperatures by using hot soap technique. The synthesis was based on the thermal decomposition of organometallic compounds precipitated in a hot coordinating solvent. Moderate heat treatment at low temperature far below the combustion point of organic compounds produced spherical LaFeO{sub 3} nanoparticles with average diameter of about 15 nm. The crystalline phase, structure and particle size of obtained products were characterized by X-ray diffraction, infrared spectroscopy and transmission electron microscopy observations. In spite of the antiferromagnetic nature of bulk LaFeO{sub 3}, the obtained nanoparticles exhibited anomalous large magnetization. Superparamagnetic behavior with a blocking temperature of about 30 K was observed in both magnetization and Moessbauer spectroscopic analyses.

  13. Fabrication of γ-Fe2O3 Nanoparticles by Solid-State Thermolysis of a Metal-Organic Framework, MIL-100(Fe, for Heavy Metal Ions Removal

    Directory of Open Access Journals (Sweden)

    Shengtao Hei

    2014-01-01

    Full Text Available Porous γ-Fe2O3 nanoparticles were prepared via a solid-state conversion process of a mesoporous iron(III carboxylate crystal, MIL-100(Fe. First, the MIL-100(Fe crystal that served as the template of the metal oxide was synthesized by a low-temperature (<100°C synthesis route. Subsequently, the porous γ-Fe2O3 nanoparticles were fabricated by facile thermolysis of the MIL-100(Fe powders via a two-step calcination treatment. The obtained γ-Fe2O3 was characterized by X-ray diffraction (XRD, N2 adsorption, X-ray photoelectron spectroscopy (XPS, and scanning electron microscopy (SEM techniques, and then used as an adsorbent for heavy metal ions removal in water treatment. This study illustrates that the metal-organic frameworks may be suitable precursors for the fabrication of metal oxides nanomaterials with large specific surface area, and the prepared porous γ-Fe2O3 exhibits a superior adsorption performance for As(V and As(III ions removal in water treatment.

  14. Ion-irradiation induced chemical ordering of FePt and FePtAu nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Seetala, Naidu V. [Department of Physics, Grambling State University, RWE Jones Drive, Carver Hall 81, Grambling, LA 71245 (United States)]. E-mail: naidusv@gram.edu; Harrell, J.W. [MINT Center, University of Alabama, Tuscaloosa, AL 35487 (United States); Lawson, Jeremy [MINT Center, University of Alabama, Tuscaloosa, AL 35487 (United States); Nikles, David E. [MINT Center, University of Alabama, Tuscaloosa, AL 35487 (United States); Williams, John R. [Department of Physics, Auburn University, Auburn, AL 36849 (United States); Isaacs-Smith, Tamara [Department of Physics, Auburn University, Auburn, AL 36849 (United States)

    2005-12-15

    We have studied the effect of ion-beam irradiation on reducing the ordering temperature of FePt and FePtAu nanoparticles. FePt and FePt(Au14%) 4 nm particles dispersed on a Si-substrate were irradiated by 300 keV Al-ions with a dose of 1 x 10{sup 16} ions/cm{sup 2} at 43 {sup o}C using a water-cooled flange in order to minimize the vacancy migration and voids formation within the collision cascades. Partial chemical ordering has been observed in as-irradiated particles with coercivity of 60-130 Oe. Post-irradiation annealing at 220 {sup o}C enhanced chemical ordering in FePt nanoparticles with coercivity of 3500 Oe, magnetic anisotropy of 1.5 x 10{sup 7} erg/cc, and thermal stability factor of 130. A much higher 375 {sup o}C post-irradiation annealing was required in FePtAu, presumably because Au atoms were trapped at Fe/Pt lattice sites at lower temperatures. As the annealing temperature increased, anomalous features in the magnetization reversal curves were observed that disappeared at higher annealing temperatures.

  15. Structural, optical, and magnetic properties of Mn and Fe-doped Co3O4 nanoparticles

    Directory of Open Access Journals (Sweden)

    C. Stella

    2015-08-01

    Full Text Available Mn and Fe-doped Co3O4 nanoparticles were prepared by a simple precipitation method. The synthesized particles were characterized by X-ray diffraction (XRD, scanning electron microscope (SEM, transmission electron microscope (TEM, UV-Vis absorption spectroscopy, Fourier transform infrared spectroscopy (FTIR, Raman spectroscopy, and vibrating sample magnetometer (VSM techniques. XRD analysis showed the cubic structure of Co3O4. SEM and TEM images confirmed the formation of interconnected nanoparticles. Mn and Fe-doped Co3O4 showed broad absorption in the visible region compared to undoped sample and the band gap values are red shifted. Five Raman active modes were observed from the Raman spectra. FTIR spectra confirmed the spinel structure of Co3O4 and the doping of Mn and Fe shifts the vibrational modes to lower wave number region. The magnetic measurements confirmed that Fe-doped Co3O4 shows a little ferromagnetic behavior compared to undoped and Mn-doped Co3O4, which could be related to the uncompensated surface spins and the finite size effects.

  16. Structural, Optical, and Electronic Characterization of Fe-Doped Alumina Nanoparticles

    Science.gov (United States)

    Heiba, Zein K.; Mohamed, Mohamed Bakr; Wahba, Adel Maher; Imam, N. G.

    2018-01-01

    The effects of iron doping on the structural, optical, and electronic properties of doped alumina have been studied. Single-phase iron-doped alumina Al2- x Fe x O3 ( x = 0.00 to 0.30) nanoparticles were synthesized via citrate-precursor method. Formation of single-phase hexagonal corundum structure with no other separate phases was demonstrated by x-ray diffraction (XRD) analysis and Fourier-transform infrared spectroscopy. The effects of iron doping on the α-Al2O3 structural parameters, viz. atomic coordinates, lattice parameters, crystallite size, and microstrain, were estimated from XRD data by applying the Rietveld profile fitting method. Transmission electron microscopy further confirmed the nanosize nature of the prepared samples with size ranging from 12 nm to 83 nm. The electronic band structure was investigated using density functional theory calculations to explain the decrease in the energy gap of Al2- x Fe x O3 as the amount of Fe was increased. The colored emission peaks in the visible region (blue, red, violet) of the electromagnetic spectrum obtained for the Fe-doped α-Al2O3 nanoparticles suggest their potential application as ceramic nanopigments.

  17. Magnetic properties of Fe-doped NiO nanoparticles

    Science.gov (United States)

    Kurokawa, A.; Sakai, N.; Zhu, L.; Takeuchi, H.; Yano, S.; Yanoh, T.; Onuma, K.; Kondo, T.; Miike, K.; Miyasaka, T.; Ichiyanagi, Y.

    2013-08-01

    Ni1- x Fe x O ( x = 0, 0.05, 0.1) nanoparticles with several nanometers encapsulated with amorphous SiO2 were prepared by our novel preparation method. A NiO single phase structure was confirmed using the X-ray diffraction measurements. It is considered that Ni ions are replaced by Fe ions because it is observed that the lattice constant decreases. The temperature dependence behavior of the magnetization revealed that the blocking temperature, T B , shifted from 17 to 57 K as the amount of Fe ions increased, and that below T B , ferromagnetic behaviors were exhibited. The coercive force, H C , increased from 0.8 to 1.5 kOe as the amount of Fe ions increased.

  18. Uniform silver/polypyrrole core-shell nanoparticles synthesized by hydrothermal reaction

    Energy Technology Data Exchange (ETDEWEB)

    Wang Shibin [Department of Chemistry, Tsinghua University, Beijing 100084 (China); Shi Gaoquan [Department of Chemistry, Tsinghua University, Beijing 100084 (China)]. E-mail: gshi@tsinghua.edu.cn

    2007-04-15

    Uniformly sized silver/polypyrrole (Ag/PPy) core-shell nanoparticles were synthesized by one-step hydrothermal reaction of pyrrole and silver nitrate in the presence of polyvinyl pyrrolidone (PVP) as protection agent. The morphology and structures of the nanoparticles have been studied by scanning and transmission electronic microscopes, X-ray diffractometer and Raman spectroscopy. The experimental results indicated that the particles had 120 nm silver cores with 20 nm polypyrrole (PPy) coatings. The reaction conditions have strong effects on the morphology of the nanoparticles.

  19. Uniform silver/polypyrrole core-shell nanoparticles synthesized by hydrothermal reaction

    International Nuclear Information System (INIS)

    Wang Shibin; Shi Gaoquan

    2007-01-01

    Uniformly sized silver/polypyrrole (Ag/PPy) core-shell nanoparticles were synthesized by one-step hydrothermal reaction of pyrrole and silver nitrate in the presence of polyvinyl pyrrolidone (PVP) as protection agent. The morphology and structures of the nanoparticles have been studied by scanning and transmission electronic microscopes, X-ray diffractometer and Raman spectroscopy. The experimental results indicated that the particles had 120 nm silver cores with 20 nm polypyrrole (PPy) coatings. The reaction conditions have strong effects on the morphology of the nanoparticles

  20. Measurement of discrete energy-level spectra in individual chemically synthesized gold nanoparticles

    DEFF Research Database (Denmark)

    Kuemmeth, Ferdinand; Bolotin, Kirill I; Shi, Su-Fei

    2008-01-01

    We form single-electron transistors from individual chemically synthesized gold nanoparticles, 5-15 nm in diameter, with monolayers of organic molecules serving as tunnel barriers. These devices allow us to measure the discrete electronic energy levels of individual gold nanoparticles that are......, by virtue of chemical synthesis, well-defined in their composition, size and shape. We show that the nanoparticles are nonmagnetic and have spectra in good accord with random-matrix-theory predictions taking into account strong spin-orbit coupling....

  1. Influence of Irradiation Time on properties of CdS Nanoparticles Synthesized using Microwave Irradiation

    International Nuclear Information System (INIS)

    Nayereh Soltani; Elias SSaion; Maryam Erfani; Mohd Zobir Hussein; Robiah Yunus

    2011-01-01

    Different sizes of cadmium sulfide nanoparticles which exhibit obvious quantum confinement effect have been synthesized of cadmium chloride and thioacetamide through the simple and rapid microwave method. The properties of these CdS nanoparticles were examined with varying irradiation time from 10 to 40 min using a pulse regime. The obtained CdS particles were characterized by X-ray diffraction (XRD), transition electron microscopy (TEM) and UV-visible (UV-Vis) spectroscopy. The effects of irradiation time on the size, degree of crystallinity, yield of reaction and optical band gap of CdS nanoparticles are investigated. (author)

  2. Synthesis of TiO2 nanoparticles containing Fe, Si, and V using multiple diffusion flames and catalytic oxidation capability of carbon-coated nanoparticles

    KAUST Repository

    Ismail, Mohamed

    2016-01-19

    Titanium dioxide (TiO2) nanoparticles containing iron, silicon, and vanadium are synthesized using multiple diffusion flames. The growth of carbon-coated (C–TiO2), carbon-coated with iron oxide (Fe/C–TiO2), silica-coated (Si–TiO2), and vanadium-doped (V–TiO2) TiO2 nanoparticles is demonstrated using a single-step process. Hydrogen, oxygen, and argon are utilized to establish the flame, with titanium tetraisopropoxide (TTIP) as the precursor for TiO2. For the growth of Fe/C–TiO2 nanoparticles, TTIP is mixed with xylene and ferrocene. While for the growth of Si–TiO2 and V–TiO2, TTIP is mixed with hexamethyldisiloxane (HMDSO) and vanadium (V) oxytriisopropoxide, respectively. The synthesized nanoparticles are characterized using high-resolution transmission electron microscopy (HRTEM) with energy-filtered TEM for elemental mapping (of Si, C, O, and Ti), X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), nitrogen adsorption BET surface area analysis, and thermogravimetric analysis. Anatase is the dominant phase for the C–TiO2, Fe/C–TiO2, and Si–TiO2 nanoparticles, whereas rutile is the dominant phase for the V–TiO2 nanoparticles. For C–TiO2 and Fe/C–TiO2, the nanoparticles are coated with about 3-5-nm thickness of carbon. The iron-based TiO2 nanoparticles significantly improve the catalytic oxidation of carbon, where complete oxidation of carbon occurs at a temperature of 470 °C (with iron) compared to 610 °C (without iron). Enhanced catalytic oxidation properties are also observed for model soot particles, Printex-U, when mixed with Fe/C-TiO2. With regards to Si–TiO2 nanoparticles, a uniform coating of 3 to 8 nm of silicon dioxide is observed around the TiO2 particles. This coating mainly occurs due to variance in the chemical reaction rates of the precursors. Finally, with regards to V–TiO2, vanadium is doped within the TiO2 nanoparticles as visualized by HRTEM and XPS further confirms the formation of

  3. Synthesis of TiO{sub 2} nanoparticles containing Fe, Si, and V using multiple diffusion flames and catalytic oxidation capability of carbon-coated nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Ismail, Mohamed A. [King Abdullah University of Science and Technology (KAUST), Clean Combustion Research Center (Saudi Arabia); Memon, Nasir K., E-mail: nmemon@qf.org.qa [HBKU, Qatar Foundation, Qatar Environment and Energy Research Institute (QEERI) (Qatar); Hedhili, Mohamed N.; Anjum, Dalaver H. [KAUST, Imaging and Characterization Lab (Saudi Arabia); Chung, Suk Ho [King Abdullah University of Science and Technology (KAUST), Clean Combustion Research Center (Saudi Arabia)

    2016-01-15

    Titanium dioxide (TiO{sub 2}) nanoparticles containing iron, silicon, and vanadium are synthesized using multiple diffusion flames. The growth of carbon-coated (C–TiO{sub 2}), carbon-coated with iron oxide (Fe/C–TiO{sub 2}), silica-coated (Si–TiO{sub 2}), and vanadium-doped (V–TiO{sub 2}) TiO{sub 2} nanoparticles is demonstrated using a single-step process. Hydrogen, oxygen, and argon are utilized to establish the flame, with titanium tetraisopropoxide (TTIP) as the precursor for TiO{sub 2}. For the growth of Fe/C–TiO{sub 2} nanoparticles, TTIP is mixed with xylene and ferrocene. While for the growth of Si–TiO{sub 2} and V–TiO{sub 2}, TTIP is mixed with hexamethyldisiloxane (HMDSO) and vanadium (V) oxytriisopropoxide, respectively. The synthesized nanoparticles are characterized using high-resolution transmission electron microscopy (HRTEM) with energy-filtered TEM for elemental mapping (of Si, C, O, and Ti), X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), nitrogen adsorption BET surface area analysis, and thermogravimetric analysis. Anatase is the dominant phase for the C–TiO{sub 2}, Fe/C–TiO{sub 2}, and Si–TiO{sub 2} nanoparticles, whereas rutile is the dominant phase for the V–TiO{sub 2} nanoparticles. For C–TiO{sub 2} and Fe/C–TiO{sub 2}, the nanoparticles are coated with about 3-5-nm thickness of carbon. The iron-based TiO{sub 2} nanoparticles significantly improve the catalytic oxidation of carbon, where complete oxidation of carbon occurs at a temperature of 470 °C (with iron) compared to 610 °C (without iron). Enhanced catalytic oxidation properties are also observed for model soot particles, Printex-U, when mixed with Fe/C-TiO{sub 2}. With regards to Si–TiO{sub 2} nanoparticles, a uniform coating of 3 to 8 nm of silicon dioxide is observed around the TiO{sub 2} particles. This coating mainly occurs due to variance in the chemical reaction rates of the precursors. Finally, with regards

  4. Synthesis of TiO2 nanoparticles containing Fe, Si, and V using multiple diffusion flames and catalytic oxidation capability of carbon-coated nanoparticles

    KAUST Repository

    Ismail, Mohamed; Memon, Nasir K.; Hedhili, Mohamed N.; Anjum, Dalaver H.; Chung, Suk-Ho

    2016-01-01

    Titanium dioxide (TiO2) nanoparticles containing iron, silicon, and vanadium are synthesized using multiple diffusion flames. The growth of carbon-coated (C–TiO2), carbon-coated with iron oxide (Fe/C–TiO2), silica-coated (Si–TiO2), and vanadium-doped (V–TiO2) TiO2 nanoparticles is demonstrated using a single-step process. Hydrogen, oxygen, and argon are utilized to establish the flame, with titanium tetraisopropoxide (TTIP) as the precursor for TiO2. For the growth of Fe/C–TiO2 nanoparticles, TTIP is mixed with xylene and ferrocene. While for the growth of Si–TiO2 and V–TiO2, TTIP is mixed with hexamethyldisiloxane (HMDSO) and vanadium (V) oxytriisopropoxide, respectively. The synthesized nanoparticles are characterized using high-resolution transmission electron microscopy (HRTEM) with energy-filtered TEM for elemental mapping (of Si, C, O, and Ti), X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), nitrogen adsorption BET surface area analysis, and thermogravimetric analysis. Anatase is the dominant phase for the C–TiO2, Fe/C–TiO2, and Si–TiO2 nanoparticles, whereas rutile is the dominant phase for the V–TiO2 nanoparticles. For C–TiO2 and Fe/C–TiO2, the nanoparticles are coated with about 3-5-nm thickness of carbon. The iron-based TiO2 nanoparticles significantly improve the catalytic oxidation of carbon, where complete oxidation of carbon occurs at a temperature of 470 °C (with iron) compared to 610 °C (without iron). Enhanced catalytic oxidation properties are also observed for model soot particles, Printex-U, when mixed with Fe/C-TiO2. With regards to Si–TiO2 nanoparticles, a uniform coating of 3 to 8 nm of silicon dioxide is observed around the TiO2 particles. This coating mainly occurs due to variance in the chemical reaction rates of the precursors. Finally, with regards to V–TiO2, vanadium is doped within the TiO2 nanoparticles as visualized by HRTEM and XPS further confirms the formation of

  5. Fe{sub 3}O{sub 4} magnetic core coated by silver and functionalized with N-acetyl cysteine as novel nanoparticles in ferritin adsorption

    Energy Technology Data Exchange (ETDEWEB)

    Akduman, Beguem [Faculty of Science and Arts, Adnan Menderes University, Department of Chemistry (Turkey); Uygun, Murat [Kocarl Latin-Small-Letter-Dotless-I Vocational and Training School, Adnan Menderes University (Turkey); Uygun, Deniz Aktas, E-mail: daktas@adu.edu.tr [Faculty of Science and Arts, Adnan Menderes University, Department of Chemistry (Turkey); Antalik, Marian [Institute of Experimental Physics, Slovak Academy of Science, Department of Biophysics (Slovakia)

    2013-04-15

    A novel metal-chelate affinity matrix utilizing N-acetyl cysteine as a metal chelating agent was synthesized. For this, magnetic Fe{sub 3}O{sub 4} core was coated with silver by chemical reduction. Then, these magnetic silver nanoparticles were covered with N-acetyl cysteine, and Fe{sup 3+} was chelated to this modified magnetic silver nanoparticle. These magnetic nanoparticles were characterized by SEM, AFM, EDX, and ESR analysis. Synthesized nanoparticles were spherical and average size is found to be 69 nm. Fe{sup 3+} chelated magnetic silver nanoparticles were used for the adsorption of ferritin from its aqueous solution. Optimum conditions for the ferritin adsorption experiments were performed at pH 6.0 phosphate buffer and 25 Degree-Sign C of medium temperature and the maximum ferritin adsorption capacity is found to be 89.57 mg/g nanoparticle. Ferritin adsorption onto magnetic silver nanoparticles was increased with increasing ferritin concentration while adsorption capacity was decreased with increasing ionic strength. Affinity of the magnetic silver nanoparticles to the ferritin molecule was shown with SPR analysis. It was also observed that the adsorption capacity of the magnetic silver nanoparticles was not significantly changed after the five adsorption/desorption cycles.

  6. Studies on polyethylene glycol coating on NiFe2O4 nanoparticles for biomedical applications

    International Nuclear Information System (INIS)

    Phadatare, M.R.; Khot, V.M.; Salunkhe, A.B.; Thorat, N.D.; Pawar, S.H.

    2012-01-01

    The NiFe 2 O 4 nanoparticles were prepared by the combustion method and these nanoparticles were successfully coated with polyethylene glycol (PEG) for the possible biomedical applications such as magnetic resonance imaging, drug delivery, tissue repair, magnetic fluid hyperthermia etc. The structural and magnetic characterizations of NiFe 2 O 4 nanoparticles were carried out by x-ray diffraction and vibrating sample magnetometry techniques, respectively. The morphology of the uncoated and coated nanoparticles was studied by scanning electron microscopy. The existence of PEG layer on NiFe 2 O 4 nanoparticles was confirmed by fourier transform infrared spectroscopy technique. - Highlights: ► Synthesis of nanocrystalline NiFe 2 O 4 by the combustion method. ► Magnetic properties of the NiFe 2 O 4 nanoparticles at room temperature. ► Coating of NiFe 2 O 4 nanoparticles by Polyethylene glycol (PEG).

  7. Green synthesis of soya bean sprouts-mediated superparamagnetic Fe{sub 3}O{sub 4} nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Cai Yan [School of Chemistry and Chemical Engineering, Anhui University, Hefei 230039 (China); Shen Yuhua, E-mail: s_yuhua@163.co [School of Chemistry and Chemical Engineering, Anhui University, Hefei 230039 (China) and State Key Laboratory of Coordination Chemistry, Nanjing University, Nanjing 210093 (China); Xie Anjian, E-mail: anjx@163.co [School of Chemistry and Chemical Engineering, Anhui University, Hefei 230039 (China) and State Key Laboratory of Coordination Chemistry, Nanjing University, Nanjing 210093 (China); Li Shikuo; Wang Xiufang [School of Chemistry and Chemical Engineering, Anhui University, Hefei 230039 (China)

    2010-10-15

    Superparamagnetic Fe{sub 3}O{sub 4} nanoparticles were first synthesized via soya bean sprouts (SBS) templates under ambient temperature and normal atmosphere. The reaction process was simple, eco-friendly, and convenient to handle. The morphology and crystalline phase of the nanoparticles were determined from scanning electron microscopy (SEM), transmission electron microscopy (TEM), selected area electron diffraction (SAED), and X-ray diffraction (XRD) spectra. The effect of SBS template on the formation of Fe{sub 3}O{sub 4} nanoparticles was investigated using X-ray photoemission spectroscopy (XPS) and Fourier-transform infrared spectroscopy (FT-IR). The results indicate that spherical Fe{sub 3}O{sub 4} nanoparticles with an average diameter of 8 nm simultaneously formed on the epidermal surface and the interior stem wall of SBS. The SBS are responsible for size and morphology control during the whole formation of Fe{sub 3}O{sub 4} nanoparticles. In addition, the superconducting quantum interference device (SQUID) results indicate the products are superparamagnetic at room temperature, with blocking temperature (T{sub B}) of 150 K and saturation magnetization of 37.1 emu/g.

  8. Selective binding and magnetic separation of His-tagged proteins using Fe3O4/PAM/NTA-Ni2+ Magnetic Nanoparticles

    Science.gov (United States)

    Guo, Huiling; Li, Mengyun; Tu, Shu; Sun, Honghao

    2018-03-01

    Fe3O4 nanoparticles coated with polyacrylamide (PAM) were synthesized. The magnetic core, with an average hydrodynamic size of 235.5 nm, allowed the magnetic nanoparticles (MNPs) rapid separation from solutions under an external magnetic field. NTA-Ni2+ was modified on the surface of Fe3O4/PAM MNPs to selectively trap his-tagged green fluorescent protein (GFP). The results showed that Fe3O4/PAM/NTA-Ni2+ MNPs exhibited remarkable capability of selective binding and separating his-tagged GFP. The adsorption efficiency was 93.37%.

  9. Enhanced visible light-responsive photocatalytic activity of LnFeO3 (Ln = La, Sm) nanoparticles by synergistic catalysis

    International Nuclear Information System (INIS)

    Li, Li; Wang, Xiong; Zhang, Yange

    2014-01-01

    Highlights: • LnFeO 3 (Ln = La, Sm) nanoparticles were prepared by a facile sol–gel method. • The samples exhibit superior visible-light-responsive photocatalytic activity. • Synergistic effect will enhance the photodegradation of RhB under visible light. - Abstract: LnFeO 3 (Ln = La, Sm) nanoparticles were prepared by a facile sol–gel method with assistance of glycol at different calcination temperatures. The as-synthesized LnFeO 3 was characterized by X-ray diffraction, transmission electron microscopy, differential scanning calorimeter and thermogravimetric analysis, and UV–vis absorption spectroscopy. The photocatalytic behaviors of LnFeO 3 nanoparticles were evaluated by photodegradation of rhodamine B under visible light irradiation. The results indicate that the visible light-responsive photocatalytic activity of LnFeO 3 nanoparticles was enhanced remarkably by the synergistic effect between the semiconductor photocatalysis and Fenton-like reaction. And a possible catalytic mechanism was also proposed based on the experimental results

  10. Fabrication of carbon layer coated FE-nanoparticles using an electron beam irradiation

    Science.gov (United States)

    Kim, Hyun Bin; Jeun, Joon Pyo; Kang, Phil Hyun; Oh, Seung-Hwan

    2016-01-01

    A novel synthesis of carbon encapsulated Fe nanoparticles was developed in this study. Fe chloride (III) and polyacrylonitrile (PAN) were used as precursors. The crosslinking of PAN molecules and the nucleation of Fe nanoparticles were controlled by the electron beam irradiation dose. Stabilization and carbonization processes were carried out using a vacuum furnace at 275 °C and 1000 °C, respectively. Micro structures were evaluated by X-ray diffraction (XRD) and transmission electron microscopy (TEM). Fe nanoparticles were formed with diameters of 100 nm, and the Fe nanoparticles were encapsulated by carbon layers. As the electron beam irradiation dose increased, it was observed that the particle sizes decreased.

  11. Radiation induced structural and magnetic transformations in nanoparticle MnxZn(1−x)Fe2O4 ferrites

    International Nuclear Information System (INIS)

    Naik, P.P.; Tangsali, R.B.; Sonaye, B.; Sugur, S.

    2015-01-01

    Nanoparticle magnetic materials are suitable for multiple modern high end medical applications like targeted drug delivery, gene therapy, hyperthermia and MR thermometry imaging. Majority of these applications are confined to use of Mn–Zn ferrite nanoparticles. These nanoparticles are normally left in the body after their requisite application. Preparing these nanoparticles is usually a much involved job. However with the development of the simple technique Mn x Zn 1−x Fe 2 O 4 nanoparticles could be prepared with much ease. The nanoparticles of Mn x Zn 1−x Fe 2 O 4 with (x=1.0, 0.7, 0.5, 0.3, 0.0) were prepared and irradiated with gamma radiation of various intensities ranging between 500 R to 10,000 R, after appropriate structural and magnetic characterization. Irradiated samples were investigated for structural and magnetic properties, as well as for structural stability and cation distribution. The irradiated nanoparticles exhibited structural stability with varied cation distribution and magnetic properties, dependent on gamma radiation dose. Surprisingly samples also exhibited quenching of lattice parameter and particle size. The changes introduced in the cation distribution, lattice constant, particle size and magnetic properties were found to be irreversible with time lapse and were of permanent nature exhibiting good stability even after several months. Thus the useful properties of nanoparticles could be enhanced on modifying the cation distribution inside the nanoparticles by application of gamma radiation. - Highlights: • Mn x Zn 1−x Fe 2 O 4 nanoparticles were synthesized using auto combustion method. • The irradiated samples showed a change in cation distribution. • Lattice shrinkage observed due to radiation induced change in cation distribution. • Reduction in particle size was also observed due to gamma exposure. • An enhancement in saturation magnetization was observed in irradiated samples

  12. Adsorptive removal of bisphenol A using synthesized magnetite nanoparticles

    Science.gov (United States)

    Orimolade, B. O.; Adekola, F. A.; Adebayo, G. B.

    2018-03-01

    Bisphenol A (BPA) is an organic compound which is often used as plasticizer and has been reported to be hazardous to man. In this research the efficiency of removal of BPA from water by magnetite through adsorption process was studied. The magnetite was synthesized using reverse co-precipitation method and fully characterized. Various physicochemical parameters affecting the adsorption of BPA using magnetite were studied as well. The optimum time for the adsorption process was found to be 60 min at pH of 6, adsorbent dose of 0.2 g and 50 ppm of BPA. The adsorption data were fitted by the Langmuir adsorption isotherm best with a regression value of 0.957. The R L value was 0.179 which revealed that the process is favorable. The Freundlich constant n which was 1.901 also revealed that the adsorption is normal and favorable. The data were in agreement with the pseudo-second-order kinetics with regression value of 0.98. From the thermodynamic studies, the process was found to be exothermic and the Gibb's free energy value which was negative showed that the adsorption was spontaneous. The synthesized magnetite therefore offers great potential for the remediation of bisphenol A-contaminated media.

  13. Synthesis of magnetic core-shell structure Fe3O4@MCM-41 nanoparticle by vesicles in aqueous solutions☆

    Institute of Scientific and Technical Information of China (English)

    Weiming Song; Xuesong Liu; Ying Yang; Xuejia Han; Qigang Deng

    2015-01-01

    In this study, magnetic core–shel structure Fe3O4@MCM-41 nanoparticles were synthesized with vesicles as soft templates. In the preparation, FeCl2 and tetraethy orthosilicate (TEOS) were selected as Fe processor and Si pre-cursor, respectively. Stable vesicles first formed in 0.03 mol·L−1 1:2 mixture of anionic surfactant sodium dode-cyl sulfate and cationic surfactant cetyltrimethyl ammonium bromide. Then, TEOS was added in the vesicle aqueous solution, leading to a highly dispersed solution. After high-temperature calcination, Fe3O4@MCM-41 nanoparticles were obtained. Their structure and morphology were characterized by Saturn Digisizer, transmis-sion electron microscope and vibrating sample magneto-meter. The results indicate that the vesicles are spherical and their size could be tuned between 20 and 50 nm. The average grain diameter of synthesize magnetic core–shel Fe3O4@MCM-41 particles is 100–150 nm and most of them are in el iptical shape. The dispersion of magnet-ic particles is very good and magnetization values are up to 33.44 emu·g−1, which are superior to that of other Fe3O4 materials reported.

  14. Photocatalytic degradation of methylene blue on Fe3+-doped TiO2 nanoparticles under visible light irradiation

    Institute of Scientific and Technical Information of China (English)

    SU Bitao; WANG Ke; BAI Jie; MU Hongmei; TONG Yongchun; MIN Shixiong; SHE Shixiong; LEI Ziqiang

    2007-01-01

    Fe3+-doped TiO2 composite nanoparticles with different doping amounts were successfully synthesized using sol-gel method and characterized by X-ray diffraction (XRD),transmission electron microscopy (TEM) and ultraviolet-visible spectroscopy (UV-Vis) diffuse reflectance spectra (DRS). The photocatalytic degradation of methylene blue was used as a model reaction to evaluate the photocatalytic activity of Fe3+/TiO2 nanoparticles under visible light irradia-tion. The influence of doping amount of Fe3+ (ω: 0.00%-3.00%) on photocatalytic activities of TiO2 was investigated.Results show that the size of Fe3+/TiO2 particles decreases with the increase of the amount of Fe3+ and their absorptionspectra are broaden and absorption intensities are also increased. Doping Fe3+ can control the conversion of TiO2 from anatase to rutile. The doping amount of Fe3+ remarkably affects the activity of the catalyst, and the optimum efficiency occurs at about the doping amount of 0.3%. The appropriate doping of Fe3+ can markedly increase the catalytic activity of TiO2 under visible light irradiation.

  15. Facile synthesis of α-Fe{sub 2}O{sub 3} nanoparticles for high-performance CO gas sensor

    Energy Technology Data Exchange (ETDEWEB)

    Cuong, Nguyen Duc, E-mail: nguyenduccuong@hueuni.edu.vn [College of Sciences, Hue University, 77 Nguyen Hue, Phu Nhuan Ward, Hue City (Viet Nam); Faculty of Hospitality and Tourism, Hue University, 22 Lam Hoang, Vy Da Ward, Hue City (Viet Nam); Khieu, Dinh Quang; Hoa, Tran Thai [College of Sciences, Hue University, 77 Nguyen Hue, Phu Nhuan Ward, Hue City (Viet Nam); Quang, Duong Tuan [College of Education, Hue University, 34 Le Loi, Hue City (Viet Nam); Viet, Pham Hung [Centre for Environmental Technology and Sustainable Development (CETASD), Hanoi University of Science, 334 Nguyen Trai, Hanoi (Viet Nam); Lam, Tran Dai [Graduate University of Science and Technology, Vietnamese Academy of Science and Technology, Hanoi (Viet Nam); Hoa, Nguyen Duc [International Training Institute for Materials Science (ITIMS), Hanoi University of Science and Technology (HUST), No. 1, Dai Co Viet, Hanoi (Viet Nam); Hieu, Nguyen Van, E-mail: hieu@itims.edu.vn [International Training Institute for Materials Science (ITIMS), Hanoi University of Science and Technology (HUST), No. 1, Dai Co Viet, Hanoi (Viet Nam)

    2015-08-15

    Highlights: • We have demonstrated a facile method to prepare Fe{sub 2}O{sub 3} nanoparticles. • The gas sensing properties of α-Fe{sub 2}O{sub 3} have been invested. • The results show potential application of α-Fe{sub 2}O{sub 3} NPs for CO sensors in environmental monitoring. - Abstract: Iron oxide nanoparticles (NPs) were prepared via a simple hydrothermal method for high performance CO gas sensor. The synthesized α-Fe{sub 2}O{sub 3} NPs were characterized by X-ray diffraction, nitrogen adsorption/desorption isotherm, scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), and selected area electron diffraction (SAED). The SEM, TEM results revealed that obtained α-Fe{sub 2}O{sub 3} particles had a peanut-like geometry with hemispherical ends. The response of the α-Fe{sub 2}O{sub 3} NPs based sensor to carbon monoxide (CO) and various concentrations of other gases were measured at different temperatures. It found that the sensor based on the peanut-like α-Fe{sub 2}O{sub 3} NPs exhibited high response, fast response–recovery, and good selectivity to CO at 300 °C. The experimental results clearly demonstrated the potential application of α-Fe{sub 2}O{sub 3} NPs as a good sensing material in the fabrication of CO sensor.

  16. Experimental evidence for simultaneous relaxation processes in super spin glass γ-Fe2O3 nanoparticle system

    Science.gov (United States)

    Nikolic, V.; Perovic, M.; Kusigerski, V.; Boskovic, M.; Mrakovic, A.; Blanusa, J.; Spasojevic, V.

    2015-03-01

    Spherical γ-Fe2O3 nanoparticles with the narrow size distribution of (5 ± 1) nm were synthesized by the method of thermal decomposition from iron acetyl acetonate precursor. The existence of super spin-glass state at low temperatures and in low applied magnetic fields was confirmed by DC magnetization measurements on a SQUID magnetometer. The comprehensive investigation of magnetic relaxation dynamics in low-temperature region was conducted through the measurements of single-stop and multiple stop ZFC memory effects, ZFC magnetization relaxation, and AC susceptibility measurements. The experimental findings revealed the peculiar change of magnetic relaxation dynamics at T ≈ 10 K, which arose as a consequence of simultaneous existence of different relaxation processes in Fe2O3 nanoparticle system. Complementarity of the applied measurements was utilized in order to single out distinct relaxation processes as well as to elucidate complex relaxation mechanisms in the investigated interacting nanoparticle system.

  17. Gel-combustion-synthesized ZnO nanoparticles for visible light ...

    Indian Academy of Sciences (India)

    Zinc oxide nanoparticles (ZnO NPs) synthesized by the gel combustion technique using a bio-fuel, cassava starch (root tubers of Manihot esculenta), have been characterized by various techniques. The X-ray diffractionpattern reveals hexagonal wurtzite structure. The particle size averaged around 45nm with an excellent ...

  18. Biological application of green silver nanoparticle synthesized from leaf extract of Rauvolfi serpentina Benth

    Directory of Open Access Journals (Sweden)

    Sudipta Panja

    2016-07-01

    Full Text Available Objective: To synthesize silver nanoparticles (AgNPs from the leaf extract of Rauvolfia serpentina Benth and examination of their various biological activities. Methods: An ecofriendly, easy, one step, non-toxic and inexpensive approach is used, where aqueous plant extract acts as a reducing as well as stabilizing agent of AgNPs. The nanoparticles were characterized by UV-vis spectroscopy, Fourier transform infrared spectroscopy, transmission electron microscopy, X-ray diffraction, and energy-dispersive X-ray spectroscopy analysis. Results: Surface plasmon resonance of the nanoparticles was observed at 427 nm in UV-vis spectroscopy. Fourier transform infrared spectroscopy result confirms that the plant extract acts as the reducing as well as the capping agent of the AgNPs. Transmission electron microscopy indicated that the synthesized nanoparticles are spherical in shape and approximately 7–10 nm in size, whereas the crystalline nature with face-centered cubic structure of the AgNPs was detected by X-ray diffraction analysis. Presence of silver in the AgNPs is 31.43% by weight, as confirmed by energy-dispersive X-ray spectroscopy. The synthesized AgNPs have antimicrobial activities against human pathogenic microorganisms. It also shows larvicidal activity and cytotoxicity against HeLa, MCF-7 cell lines. Conclusions: Synthesized spherical shaped AgNPs from the leaf extract of Rauvolfia serpentina Benth have antimicrobial and larvicidal activities as well as cytotoxicity against HeLa and MCF-7 cell lines.

  19. Synthesizing and Playing with Magnetic Nanoparticles: A Comprehensive Approach to Amazing Magnetic Materials

    Science.gov (United States)

    Dalverny, Anne-Laure; Leyral, Géraldine; Rouessac, Florence; Bernaud, Laurent; Filhol, Jean-Sébastien

    2018-01-01

    Magnetic iron oxide nanoparticles were synthesized and stabilized using ammonium cations or poly(vinyl alcohol) to produce amazing materials such as safer aqueous ferrofluids, ferrogels, ferromagnetic inks, plastics, and nanopowders illustrating how versatile materials can be produced just by simple modifications. The synthesis is fast, reliable,…

  20. Toxicity Study of Silver Nanoparticles Synthesized from Suaeda monoica on Hep-2 Cell Line.

    Science.gov (United States)

    Satyavani, Kaliyamurthi; Gurudeeban, Selvaraj; Ramanathan, Thiruganasambandam; Balasubramanian, Thangavel

    2012-01-01

    Recently there has been fabulous excitement in the nano-biotechnological area for the study of nanoparticles synthesis using some natural biological system, which has led the growth advanced nanomaterials. This intention made us to assess the biologically synthesized silver nanoparticles from the leaf of Suaeda monoica (S.monoica) using 1 mM silver nitrate. The leaf extract of S.monoica incubated with 1 mM silver nitrate solution and characterized by UV- spectrometer and AFM. The effect of synthesized silver nanoparticles on Human Epidermoid Larynx Carcinoma cell line was evaluated by the MTT colorimetric technique. As a result we observed gradual change in the colour of extract from greenish to brown. The synthesized silver nanoparticles confirmed by UV at 430 nm and spherical shape identified in the range of 31 nm under AFM. The effect of silver nanoparticles on Human Epidermoid Larynx Carcinoma cell line exhibits a dose-dependent toxicity for the cell tested and the viability of Hep-2 cells decreased to 50 % (IC(50)) at the concentration of 500 nM. Further findings will be determined the exact mechanisms of this cost effective Nano-treatments.

  1. The mechanism for degrading Orange II based on adsorption and reduction by ion-based nanoparticles synthesized by grape leaf extract

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Fang; Yang, Die [Centre for Environmental Risk Assessment and Remediation, University of South Australia, Mawson Lakes, SA 5095 (Australia); Cooperative Research Centre for Contamination Assessment and Remediation of Environments, University of South Australia, Mawson Lakes, SA 5095 (Australia); Chen, Zuliang, E-mail: zuliang.chen@unisa.edu.au [Centre for Environmental Risk Assessment and Remediation, University of South Australia, Mawson Lakes, SA 5095 (Australia); Cooperative Research Centre for Contamination Assessment and Remediation of Environments, University of South Australia, Mawson Lakes, SA 5095 (Australia); Megharaj, Mallavarapu; Naidu, Ravendra [Centre for Environmental Risk Assessment and Remediation, University of South Australia, Mawson Lakes, SA 5095 (Australia); Cooperative Research Centre for Contamination Assessment and Remediation of Environments, University of South Australia, Mawson Lakes, SA 5095 (Australia)

    2015-10-15

    Biomolecules taken from plant extracts have often been used in the single-step synthesis of iron-based nanoparticles (Fe NPs) due to their low cost, environmental safety and sustainable properties. However, the composition of Fe NPs and the degradation mechanism of organic contaminants by them are limited because these are linked to the reactivity of Fe NPs. In this study, Fe NPs synthesized by grape leaf extract served to remove Orange II. Batch experiments showed that more than 92% of Orange II was removed by Fe NPs at high temperature based on adsorption and reduction and confirmed by kinetic studies. To understand the role of Fe NPs in the removal process of azo dye, surface analysis via X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM) were employed, showing that the Fe NPs were composed of biomolecules, hydrous iron oxides and Fe{sup 0}, thus providing evidence for the adsorption of Orange II onto hydrous iron oxides and its reduction by Fe{sup 0}. Degraded products such as 2-naphthol were identified using LC–MS analysis. A degradation mechanism based on asymmetrical azo bond cleavage for the removal of Orange II was proposed.

  2. The mechanism for degrading Orange II based on adsorption and reduction by ion-based nanoparticles synthesized by grape leaf extract

    International Nuclear Information System (INIS)

    Luo, Fang; Yang, Die; Chen, Zuliang; Megharaj, Mallavarapu; Naidu, Ravendra

    2015-01-01

    Biomolecules taken from plant extracts have often been used in the single-step synthesis of iron-based nanoparticles (Fe NPs) due to their low cost, environmental safety and sustainable properties. However, the composition of Fe NPs and the degradation mechanism of organic contaminants by them are limited because these are linked to the reactivity of Fe NPs. In this study, Fe NPs synthesized by grape leaf extract served to remove Orange II. Batch experiments showed that more than 92% of Orange II was removed by Fe NPs at high temperature based on adsorption and reduction and confirmed by kinetic studies. To understand the role of Fe NPs in the removal process of azo dye, surface analysis via X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM) were employed, showing that the Fe NPs were composed of biomolecules, hydrous iron oxides and Fe 0 , thus providing evidence for the adsorption of Orange II onto hydrous iron oxides and its reduction by Fe 0 . Degraded products such as 2-naphthol were identified using LC–MS analysis. A degradation mechanism based on asymmetrical azo bond cleavage for the removal of Orange II was proposed

  3. Structural and morphological study of Zn0.9Mn0.05Fe0.05O synthesized by sol-gel wet chemical precipitation route

    Science.gov (United States)

    Jain, S. K.; Dolia, S. N.; Choudhary, B. L.; Prashant, B. L.

    2018-04-01

    Transition metal substituted Zinc oxide (ZnO) has drawn a great deal of attention due to its excellent properties. Zn0.9Mn0.05Fe0.05O sample synthesized was by Sol-gel wet chemical precipitation route at temperature 350°C. The crystallinity and the structure of Zn0.9Mn0.05Fe0.05O was determined by X-ray diffraction by Cu-Kα radiations operated at 40kV and 35mA in the range of 20° to 80°. The pattern gets indexed in wurtzite (hexagonal) structure with lattice constants a=b=3.2525Å and c=5.2071Å and approves the single phase material with no impurity. The values of particle size assessed by Debye Scherer’s (DS) formula lie in the range of 13nm to 33nm indicating the nano-crystalline nature of the sample. The morphological analysis of the sample was performed by Scanning electron microscopy (SEM) and Transmission electron microscopy (TEM) measurements. The observed size of Zn0.9Mn0.05Fe0.05O nanoparticles by TEM micrograph exhibits the similar trend with the size calculated by Debye-Scherer formula. TEM image show the irregular shape of the nanoparticles and particle size lies in the range of 10-35nm. Similar to SEM image, the slight agglomeration of the nanoparticles have been observed from TEM.

  4. Influence of different synthesis conditions on properties of oleic acid-coated-Fe3O4 nanoparticles

    Directory of Open Access Journals (Sweden)

    Aliakbari Atieh

    2015-03-01

    Full Text Available In the present paper, iron oxide nanoparticles coated by oleic acid have been synthesized in different conditions by coprecipitation method. For investigating the effect of time spent on adding the oleic acid to the precursor solution, two different processes have been considered. The as synthesized samples were characterized by X-ray diffraction (XRD, transmission electron microscopy (TEM and Fourier transform infrared spectroscopy (FT-IR. Magnetic measurement was carried out at room temperature using a vibrating sample magnetometer (VSM. The results show that the magnetic nanoparticles decorated with oleic acid decreased the saturation of magnetization. From the data, it can also be concluded that the magnetization of Fe3O4/oleic acid nanoparticles depends on synthesis conditions.

  5. Photocatalytic performances and activities of Ag-doped CuFe{sub 2}O{sub 4} nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Zhengru, E-mail: zhengruzhu@gmail.com [Research Center of Hydrology and Water Source, School of Urban and Environment, Liaoning Normal University, Dalian, 116029 (China); State Key Laboratory of Fine Chemical, Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), School of Environmental Science and Technology, Dalian University of Technology, Dalian, 116024 (China); Li, Xinyong; Zhao, Qidong [State Key Laboratory of Fine Chemical, Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), School of Environmental Science and Technology, Dalian University of Technology, Dalian, 116024 (China); Li, Yonghua; Sun, Caizhi; Cao, Yongqiang [Research Center of Hydrology and Water Source, School of Urban and Environment, Liaoning Normal University, Dalian, 116029 (China)

    2013-08-01

    Graphical abstract: - Highlights: • CuFe{sub 2}O{sub 4} nanocrystals were synthesized by a co-precipitation method. • Ag/CuFe{sub 2}O{sub 4} catalyst was prepared by the wetness impregnation strategy. • The structural properties of Ag/CuFe{sub 2}O{sub 4} were investigated by XRD, TEM, DRS, and XPS techniques. • Ag/CuFe{sub 2}O{sub 4} has higher photocatalytic activity. - Abstract: In this work, CuFe{sub 2}O{sub 4} nanoparticles were synthesized by a chemical co-precipitation route. The Ag/CuFe{sub 2}O{sub 4} catalyst was prepared based on the CuFe{sub 2}O{sub 4} nanoparticles by the incipient wetness impregnation strategy, which showed excellent photoelectric property and catalytic activity. The structural properties of these samples were systematically investigated by X-ray powder diffraction (XRD), transmission electronic microscopy (TEM), UV–vis diffuse reflectance spectroscopy (DRS), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FT-IR) techniques. The photo-induced charge separation in the samples was demonstrated by surface photovoltage (SPV) measurement. The photocatalytic degradation of 4-CP by the Ag/CuFe{sub 2}O{sub 4} and CuFe{sub 2}O{sub 4} samples were comparatively studied under xenon lamp irradiation. The results indicate that the Ag/CuFe{sub 2}O{sub 4} sample exhibited the higher efficiency for the degradation of 4-CP.

  6. Quorum quenching and antibacterial activity of silver nanoparticles synthesized from Sargassum polyphyllum

    Directory of Open Access Journals (Sweden)

    Mani Arunkumar

    2014-03-01

    Full Text Available Development of efficient methodology for the green synthesis of silver nanoparticles using marine algae is a modern area of research in the field of phyconanotechnology. In this regard, the present study deals with green synthesis of silver nanoparticles (AgNPs by using aqueous extracts of marine brown seaweed Sargassum polyphyllum. UV-visible spectral analysis reveals the formation of AgNPs by showing absorption maximum at 420 nm wavelength and SEM analysis clearly elucidate the polydispersed structure of AgNPs without aggregation and ranged in size from 37-43 nm. X-ray Diffraction pattern confirmed the AgNPs crystalline personality. The synthesized AgNPs showed more enduring antibacterial activity against test bacterial pathogens. Furthermore, the synthesized AgNPs exhibited varying level of inhibition of violacein production and swarming motility. In the near future, silver nanoparticles can be extremely useful in clinical medicine as an alternative method for the treatment of wound infection.

  7. Effect of chemically and biologically synthesized Ag nanoparticles on the algae growth inhibition

    Science.gov (United States)

    Anna, Mražiková; Oksana, Velgosová; Jana, Kavuličová

    2017-12-01

    Over the past few years green methods for preparation of silver nanoparticles has become necessary due to its friendly influence on ecosystem. In the present work antimicrobial properties of biologically synthesized silver nanoparticles (Bio-AgNPs) using green algae extract and chemically synthesized silver nanoparticles (Chem-AgNPs) using sodium citrate against algae Parachlorella kessleri is investigated. Both used Bio-AgNPs and Chem-AgNPs exhibit long-term stability as demonstrated by UV-vis spectroscopy measurements. The results revealed stronger toxic effects of Bio-AgNPs on agar plates what was confirmed clear inhibition zone around wells impregnated with Bio-AgNPs. On the other hand Bio-AgNPs were confirmed to be less toxic in aquatic environments for the growths of green algae P. kessleri comparing to Chem-AgNPs.

  8. Decoration of carbon nanotube with size-controlled L10-FePt nanoparticles for storage media

    Science.gov (United States)

    Moradi, Reza; Sebt, Seyed Ali; Arabi, Hadi; Larijani, Majid Mojtahedzadeh

    2013-10-01

    In this work, first multi-wall carbon nanotubes (MWCNTs) with outer diameter about 20-30 nm are synthesized by a CVD method; they have been purified and functionalized with a two-step process. The approach consists of thermal oxidation and subsequent chemical oxidation. Then, monosize FePt nanoparticles along carbon nanotubes surface are synthesized by a Polyol process. The synthesized FePt nanoparticles are about 2.5 nm in size and they have superparamagnetic behavior with fcc structure. The CNTs surfaces as a substrate prevent the coalescence of particles during thermal annealing. Annealing at the temperature higher than 600 ∘C for 2 h under a reducing atmosphere (90 % Ar + 10 % H2) leads to phase transition from fcc to fct-L10 structure. So, the magnetic behavior changes from the superparamagnetic to the ferromagnetic. Furthermore, after the phase transition, the FePt nanoparticles have finite size with an average of about 3.5 nm and the coercivity of particles reaches 5.1 kOe.

  9. Mn doped GaN nanoparticles synthesized by rapid thermal treatment in ammonia

    International Nuclear Information System (INIS)

    Šimek, P.; Sedmidubský, D.; Huber, Š.; Klímová, K.; Maryško, M.; Mikulics, M.; Sofer, Z.

    2015-01-01

    We present a novel route for the synthesis of manganese doped GaN nanoparticles. Nanoparticles in the form of hexagonal discs were synthesized by rapid thermal treatment of manganese doped ammonium hexafluorogallate in ammonium atmosphere. The morphology of GaN:Mn nanoparticles was investigated using scanning electron microscopy. A concentration over 0.7 wt.% of Mn was observed by X-ray fluorescence and electron microprobe. Structural and electronic properties were investigated using X-ray diffraction, Raman spectroscopy and micro-photoluminescence with excitation wavelength of 325 nm and 532 nm. The magnetic properties between 4.5 K and 300 K were investigated by a superconducting quantum interference device (SQUID) magnetometer. GaN:Mn nanoparticles show a purely paramagnetic behavior which can be interpreted in terms of Mn 2+ ions exhibiting an antiferromagnetic interaction. - Highlights: • A new method for the synthesis of Mn doped GaN nanoparticles. • GaN:Mn nanoparticles form hexagonal discs. • None ferromagnetic ordering observed in GaN:Mn nanoparticles. • The concentration of Mn in GaN:Mn nanoparticles reach up to 0.8 wt.%

  10. Photocatalytic activity of biogenic silver nanoparticles synthesized using potato (Solanum tuberosum) infusion.

    Science.gov (United States)

    Roy, Kaushik; Sarkar, C K; Ghosh, C K

    2015-07-05

    In this study, we have reported a fast and eco-benign procedure to synthesis silver nanoparticle at room temperature using potato (Solanum tuberosum) infusion along with the study of its photocatalytic activity on methyl orange dye. After addition of potato infusion to silver nitrate solution, the color of the mixture changed indicating formation of silver nanoparticles. Time dependent UV-Vis spectra were obtained to study the rate of nanoparticle formation with time. Purity and crystallinity of the biogenic silver nanoparticles were examined by X-ray diffraction (XRD). Average size and morphology of the nanoparticles were characterized by dynamic light scattering (DLS) and transmission electron microscopy (TEM). Fourier transform infra-red spectroscopy (FTIR) was employed to detect functional bio-molecules responsible that contribute to the reduction and capping of biosynthesized Ag nanoparticles. Further, these synthesized nanoparticles were used to investigate their ability to degrade methyl orange dye under sunlight irradiation and the results showed effective photocatalytic property of these biogenic silver nanoparticles. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Bimetallic NiFe2O4 synthesized via confined carburization in NiFe-MOFs for efficient oxygen evolution reaction

    Science.gov (United States)

    Fang, Zhiqiang; Hao, Zhaomin; Dong, Qingsong; Cui, Yong

    2018-04-01

    Transition metal oxides that derived from metal-organic framework (MOF) precursor have intensively received attention because of their numerous electrochemical applications. Bimetallic Ni-Fe oxides have been rarely reported on the basis of MOF-related strategy. Herein, a bimetallic NiFe2O4 was successfully synthesized via confined carburization in NiFe-MOF precursors and characterized by XRD, XPS, SEM, and TEM. After conducting an investigation of oxygen evolution reaction (OER), the as-synthesized NiFe2O4 material exhibited good catalytic efficiency and high stability and durability in alkaline media. The as-synthesized NiFe2O4 material would promote the development of MOFs in non-noble-metal OER catalyst.

  12. Morphology and composition tailoring of Co x Fe3 - x O4 nanoparticles

    Science.gov (United States)

    Fernandes de Medeiros, I. A.; Madigou, V.; Lopes-Moriyama, A. L.; Pereira de Souza, C.; Leroux, Ch.

    2018-01-01

    Nano-octahedra of cobalt ferrite Co x Fe3 - x O4 (1 ≤ x hydrothermal method using nitrates as precursors. For the first time, single-phased nano-octahedra of cobalt-rich ferrite Co x Fe3 - x O4 ( x = 1.5) were synthesized. The nano-octahedra are crystallized in a normal spinel structure, with tetrahedral sites occupied by Co2+. This specific octahedral shape was obtained with anionic, cationic, and nonionic surfactants. The nature of the surfactant influenced the chemical composition of the powder and the size of the nano-octahedra. The {100} truncation of the octahedra is more pronounced for the small particles. For the first time, single-phased nanoparticles with as much as x = 1.8 cobalt were synthesized with ethylene glycol as solvent. These nanoparticles, around 8 nm in size, have no specific shape and possess a lacunar spinel structure similar to maghemite. The samples were characterized by X-ray diffraction, transmission electron microscopy, and energy-dispersive spectroscopy.

  13. Sonochemically synthesized biocompatible zirconium phosphate nanoparticles for pH sensitive drug delivery application

    Energy Technology Data Exchange (ETDEWEB)

    Kalita, Himani, E-mail: hkalita74@gmail.com [Department of Chemistry, Indian Institute of Technology Kharagpur, West Bengal 721302 (India); Prashanth Kumar, B.N., E-mail: prasanthkumar999@gmail.com [School of Medical Science and Technology, Indian Institute of Technology Kharagpur, West Bengal 721302 (India); Konar, Suraj, E-mail: suraj.konar@gmail.com [Department of Chemistry, Indian Institute of Technology Kharagpur, West Bengal 721302 (India); Tantubay, Sangeeta, E-mail: sang.chem2@gmail.com [Department of Chemistry, Indian Institute of Technology Kharagpur, West Bengal 721302 (India); Mahto, Madhusudan Kr., E-mail: mahtomk0@gmail.com [Department of Chemistry, Indian Institute of Technology Kharagpur, West Bengal 721302 (India); Mandal, Mahitosh, E-mail: mahitosh@smst.iitkgp.ernet.in [School of Medical Science and Technology, Indian Institute of Technology Kharagpur, West Bengal 721302 (India); Pathak, Amita, E-mail: ami@chem.iitkgp.ernet.in [Department of Chemistry, Indian Institute of Technology Kharagpur, West Bengal 721302 (India)

    2016-03-01

    The present work reports the synthesis of biocompatible zirconium phosphate (ZP) nanoparticles as nanocarrier for drug delivery application. The ZP nanoparticles were synthesized via a simple sonochemical method in the presence of cetyltrimethylammonium bromide and their efficacy for the delivery of drugs has been tested through various in-vitro experiments. The particle size and BET surface area of the nanoparticles were found to be ~ 48 nm and 206.51 m{sup 2}/g respectively. The conventional MTT assay and cellular localization studies of the particles, performed on MDA-MB-231 cell lines, demonstrate their excellent biocompatibility and cellular internalization behavior. The loading of curcumin, an antitumor drug, onto the ZP nanoparticles shows the rapid drug uptake ability of the particles, while the drug release study, performed at two different pH values (at 7.4 and 5) depicts pH sensitive release-profile. The MTT assay and cellular localization studies revealed higher cellular inhibition and better bioavailability of the nanoformulated curcumin compared to free curcumin. - Highlights: • Biocompatible zirconium phosphate nanoparticles were synthesized by a simple sonochemical approach. • Curcumin was rapidly loaded onto the particles by the aid by hydrogen bond formation. • The curcumin loaded zirconium phosphate nanoparticles depict pH triggered drug release phenomenon. • The nanoformulated curcumin showed enhanced anti-tumor activity as compared to the native curcumin.

  14. Sonochemically synthesized biocompatible zirconium phosphate nanoparticles for pH sensitive drug delivery application

    International Nuclear Information System (INIS)

    Kalita, Himani; Prashanth Kumar, B.N.; Konar, Suraj; Tantubay, Sangeeta; Mahto, Madhusudan Kr.; Mandal, Mahitosh; Pathak, Amita

    2016-01-01

    The present work reports the synthesis of biocompatible zirconium phosphate (ZP) nanoparticles as nanocarrier for drug delivery application. The ZP nanoparticles were synthesized via a simple sonochemical method in the presence of cetyltrimethylammonium bromide and their efficacy for the delivery of drugs has been tested through various in-vitro experiments. The particle size and BET surface area of the nanoparticles were found to be ~ 48 nm and 206.51 m"2/g respectively. The conventional MTT assay and cellular localization studies of the particles, performed on MDA-MB-231 cell lines, demonstrate their excellent biocompatibility and cellular internalization behavior. The loading of curcumin, an antitumor drug, onto the ZP nanoparticles shows the rapid drug uptake ability of the particles, while the drug release study, performed at two different pH values (at 7.4 and 5) depicts pH sensitive release-profile. The MTT assay and cellular localization studies revealed higher cellular inhibition and better bioavailability of the nanoformulated curcumin compared to free curcumin. - Highlights: • Biocompatible zirconium phosphate nanoparticles were synthesized by a simple sonochemical approach. • Curcumin was rapidly loaded onto the particles by the aid by hydrogen bond formation. • The curcumin loaded zirconium phosphate nanoparticles depict pH triggered drug release phenomenon. • The nanoformulated curcumin showed enhanced anti-tumor activity as compared to the native curcumin.

  15. Cerium doped hydroxyapatite nanoparticles synthesized by coprecipitation method

    Directory of Open Access Journals (Sweden)

    Ciobanu Carmen Steluta

    2016-01-01

    Full Text Available The present work reports a simple coprecipitation adapted method for the synthesis of stable Ce substituted to Ca hydroxyapatite (HAp nanoparticles. The structural and morphological properties of Ce doped hydroxyapatite (Ce:HAp were characterized by X-ray diffraction (XRD, Transmission Electron Microscopy (TEM, Scanning Electron Microscopy (SEM and Energy Dispersive X-ray analysis (EDAX. The optical properties of Ce doped hydroxyapatite were also investigated using Fourier Transform Infrared (FTIR spectroscopy, FT Raman spectroscopy and photoluminescence analysis. The results of the XRD studies revealed the progressive increase in the a- and c-axes with increasing of Ce concentrations. In the FTIR studies of Ce:HAp powders a similar structure to hydroxyapatite was observed. IR and Raman wavenumbers and the peak strength of the bands associated to the P-O and O-H bonds decreases progressively with the increase of Ce concentration. All the emission maxima could be attributed to the 5d-4f transitions of Ce ions. The displacement of maximum emission bands with the increase of Cerium in the samples is in agreement with the results obtained by XRD studies. The Ce:HAp samples with xCe =0.03 and 0.05 exhibited significant antibacterial activity against Staphylococcus aureus ATCC 6538 and E. coli 714 bacterial strains compared to Ce:HAp samples with xCe =0 (pure HAp and 0.01.

  16. Adsorption process of fluoride from drinking water with magnetic core-shell Ce-Ti@Fe3O4 and Ce-Ti oxide nanoparticles.

    Science.gov (United States)

    Abo Markeb, Ahmad; Alonso, Amanda; Sánchez, Antoni; Font, Xavier

    2017-11-15

    Synthesized magnetic core-shell Ce-Ti@Fe 3 O 4 nanoparticles were tested, as an adsorbent, for fluoride removal and the adsorption studies were optimized. Adsorption capacity was compared with the synthesized Ce-Ti oxide nanoparticles. The adsorption equilibrium for the Ce-Ti@Fe 3 O 4 adsorbent was found to occur in cycles of adsorption-desorption. Although the nanoparticles suffer slight structure modifications after their reusability, they keep their adsorption capacity. Likewise, the efficiency of the Ce-Ti@Fe 3 O 4 was demonstrated when applied to real water to obtain a residual concentration of F - below the maximum contaminated level, 1.5mg/L (WHO, 2006). Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Antimicrobial and cytotoxicity effect of silver nanoparticle synthesized by Croton bonplandianum Baill. leaves

    Directory of Open Access Journals (Sweden)

    K. Khanra

    2016-01-01

    Full Text Available Objective(s: For the development of reliable, ecofriendly, less expensive process for the synthesis of silver nanoparticles and to evaluate the bactericidal, and cytotoxicity properties of silver nanoparticles synthesized from root extract of Croton bonplandianum, Baill. Materials and Methods: The synthesis of silver nanoparticles by plant part of Croton bonplandianum was carried out.  The formation of nanoparticles was confirmed by Transmission Electron Microscopy (TEM, Scanning Electron Microscopy (SEM, XRD and UV-Vis spectrophotometric analysis.  The biochemical properties were assayed by antibacterial study, cytotoxicity assay using cancer cell line.  Results: The formation of silver nanoparticles was confirmed by UV-VIS spectroscopic analysis which showed absorbance peak at 425 nm.  X-ray diffraction photograph indicated the face centered cubic structure of the synthesized AgNPs.  TEM has displayed the different dimensional images of biogenic silver nanoparticles with particle size distribution ranging from 15-40 nm with an average size of 32 nm. Silver particles are spherical in shape, clustered.  The EDX analysis was used to identify the elemental composition of synthesized AgNPs. Antibacterial activity of the synthesized AgNPs against three Gram positive and Gram negative bacteria strains like Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa carried out showed significant zones of inhibition. The cytotoxicity study by AgNPS also showed cytotoxicity on ovarian cancer cell line PA-1 and lung epithelial cancer cell line A549.  Conclusion: The present study confirms that the AgNPs have great promise as antibacterial, and anticancer agent.

  18. Bio-inspired green synthesis of Fe{sub 3}O{sub 4} spherical magnetic nanoparticles using Syzygium cumini seed extract

    Energy Technology Data Exchange (ETDEWEB)

    Venkateswarlu, Sada; Natesh Kumar, B.; Prasad, C.H.; Venkateswarlu, P.; Jyothi, N.V.V., E-mail: nvvjyothi01@gmail.com

    2014-09-15

    A novel and bio-inspired Fe{sub 3}O{sub 4} spherical magnetic nanoparticles (SMNPs) were synthesized using Syzygium cumini (S. cumini) seed extract, which is a non-toxic ecofriendly fruit waste material. S. cumini seed extract acts as a green solvent, reducing and capping agent in which sodium acetate acts as electrostatic stabilizing agent. The green synthesized nanoparticles were characterized with the help of various techniques such as X-ray diffraction (XRD), Raman spectroscopy, transmission electron microscopy (TEM), Energy-dispersive spectroscopy (EDS), Vibrating sample magnetometer (VSM), FTIR spectroscopy and nitrogen adsorption and desorption analysis techniques. The XRD study divulged that the synthesized SMNPs have inverse spinel cubic structure. The hysteresis loop of Fe{sub 3}O{sub 4} nanoparticles shows an excellent ferromagnetic behavior with saturation magnetization value of 13.6 emu/g.

  19. A soft chemical route to the synthesis of BiFeO{sub 3} nanoparticles with enhanced magnetization

    Energy Technology Data Exchange (ETDEWEB)

    Hasan, Mehedi, E-mail: mhrizvi@gce.buet.ac.bd [Department of Glass and Ceramic Engineering, Bangladesh University of Engineering and Technology, Dhaka 1000, Bangladesh (India); Islam, Md. Fakhrul, E-mail: fislam@gce.buet.ac.bd [Department of Glass and Ceramic Engineering, Bangladesh University of Engineering and Technology, Dhaka 1000, Bangladesh (India); Mahbub, Rubayyat, E-mail: rubayyatm@gce.buet.ac.bd [Department of Glass and Ceramic Engineering, Bangladesh University of Engineering and Technology, Dhaka 1000, Bangladesh (India); Hossain, Md. Sarowar, E-mail: sakil_phy@yahoo.com [S.N. Bose National Centre for Basic Sciences, Salt Lake City, Kolkata, West Bengal 700098 (India); Hakim, M.A., E-mail: hakim.akm@gmail.com [Department of Glass and Ceramic Engineering, Bangladesh University of Engineering and Technology, Dhaka 1000, Bangladesh (India)

    2016-01-15

    Highlights: • Pure BiFeO{sub 3} nanoparticles have been synthesized at relatively low temperature. • Decomposition behavior of BiFeO{sub 3} precursor gel is investigated. • Particle size dependent magnetic properties have been confirmed. • Greatly improved magnetization is observed for BiFeO{sub 3} nanostructure. - Abstract: Utilization of BiFeO{sub 3} (BFO) into modern device applications is restricted by its very low magnetic moments and high leakage current. Enhancement in magnetization is a real challenge for multiferroic BFO in the context of device miniaturization and high density information storage system. In this study a significant improvement in magnetization has been recorded for BFO nanoparticles, exploiting the beneficial effect of size confinement. BFO nanoparticles with different size in the range of 21–68 nm are synthesized via modified Pechini sol–gel approach followed by leaching with acetic acid. X-ray diffraction result confirms pure and well crystallized BFO annealed at temperature lower than 600 °C, compared to more than 800 °C for the traditional solid-state sintering process. A strong size-dependent magnetization which increases with decreasing particle size is confirmed with a value of 1.4 emu/g for 40 nm particles in contrast to 7.5 emu/g for 21 nm particles.

  20. Antimicrobial activity and physical characterization of silver nanoparticles green synthesized using nitrate reductase from Fusarium oxysporum.

    Science.gov (United States)

    Gholami-Shabani, Mohammadhassan; Akbarzadeh, Azim; Norouzian, Dariush; Amini, Abdolhossein; Gholami-Shabani, Zeynab; Imani, Afshin; Chiani, Mohsen; Riazi, Gholamhossein; Shams-Ghahfarokhi, Masoomeh; Razzaghi-Abyaneh, Mehdi

    2014-04-01

    Nanostructures from natural sources have received major attention due to wide array of biological activities and less toxicity for humans, animals, and the environment. In the present study, silver nanoparticles were successfully synthesized using a fungal nitrate reductase, and their biological activity was assessed against human pathogenic fungi and bacteria. The enzyme was isolated from Fusarium oxysporum IRAN 31C after culturing on malt extract-glucose-yeast extract-peptone (MGYP) medium. The enzyme was purified by a combination of ultrafiltration and ion exchange chromatography on DEAE Sephadex and its molecular weight was estimated by gel filtration on Sephacryl S-300. The purified enzyme had a maximum yield of 50.84 % with a final purification of 70 folds. With a molecular weight of 214 KDa, it is composed of three subunits of 125, 60, and 25 KDa. The purified enzyme was successfully used for synthesis of silver nanoparticles in a way dependent upon NADPH using gelatin as a capping agent. The synthesized silver nanoparticles were characterized by X-ray diffraction, dynamic light scattering spectroscopy, and transmission and scanning electron microscopy. These stable nonaggregating nanoparticles were spherical in shape with an average size of 50 nm and a zeta potential of -34.3. Evaluation of the antimicrobial effects of synthesized nanoparticles by disk diffusion method showed strong growth inhibitory activity against all tested human pathogenic fungi and bacteria as evident from inhibition zones that ranged from 14 to 25 mm. Successful green synthesis of biologically active silver nanoparticles by a nitrate reductase from F. oxysporum in the present work not only reduces laborious downstream steps such as purification of nanoparticle from interfering cellular components, but also provides a constant source of safe biologically-active nanomaterials with potential application in agriculture and medicine.

  1. Effect of zinc concentration on the structural and magnetic properties of mixed Co–Zn ferrites nanoparticles synthesized by sol/gel method

    Energy Technology Data Exchange (ETDEWEB)

    Ben Ali, M., E-mail: m.benali06@gmail.com [MAScIR Foundation, Institute of Nanomaterials and Nanotechnologies, Materials & Nanomaterials Center, B.P., 10100 Rabat (Morocco); Laboratory of Magnetism and the Physics of the high Energies, URAC 12, Department of Physics, B.P. 1014, Faculty of Science, Mohammed V University, Rabat (Morocco); El Maalam, K. [MAScIR Foundation, Institute of Nanomaterials and Nanotechnologies, Materials & Nanomaterials Center, B.P., 10100 Rabat (Morocco); Laboratory of Magnetism and the Physics of the high Energies, URAC 12, Department of Physics, B.P. 1014, Faculty of Science, Mohammed V University, Rabat (Morocco); El Moussaoui, H.; Mounkachi, O. [MAScIR Foundation, Institute of Nanomaterials and Nanotechnologies, Materials & Nanomaterials Center, B.P., 10100 Rabat (Morocco); Hamedoun, M., E-mail: m.hamedoun@mascir.com [MAScIR Foundation, Institute of Nanomaterials and Nanotechnologies, Materials & Nanomaterials Center, B.P., 10100 Rabat (Morocco); Masrour, R. [Laboratory of Materials, Processes, Environment and Quality, Cady Ayyed University, National School of Applied Sciences, PB 63 46000, Safi (Morocco); Hlil, E.K. [Institut Néel, CNRS-UJF, B.P. 166, 38042 Grenoble Cedex (France); Benyoussef, A. [MAScIR Foundation, Institute of Nanomaterials and Nanotechnologies, Materials & Nanomaterials Center, B.P., 10100 Rabat (Morocco); Laboratory of Magnetism and the Physics of the high Energies, URAC 12, Department of Physics, B.P. 1014, Faculty of Science, Mohammed V University, Rabat (Morocco)

    2016-01-15

    Synthesization of zinc-substituted cobalt ferrites nano-particles Co{sub 1−x}Zn{sub x}Fe{sub 2}O{sub 4} (x=0.0–0.3) has been achieved by the sol/gel method. The characterization of the synthesized nano-particles has been done by X-ray diffractometry (XRD), transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FITR). The relation between the composition and magnetic properties has been investigated by Magnetic Properties Measurement System (MPMS). The results revealed that the nanoparticles size is in the range of 11–28 nm. It was found that the zinc substitution in cobalt ferrite increases saturation magnetization from 60.92 emu/g (x=0) to 74.67 emu/g (x=0.3). Nevertheless, zinc concentrations cause a significant decrease in coercivity.▪ - Highlights: • The nanocrystals size of synthesized of Co{sub 1−x}Zn{sub x}Fe{sub 2}O{sub 4} is of 11–28 nm. • The zinc substitution in cobalt ferrite increase saturation magnetization. • The increase of zinc concentration causes a significant decrease in coercivity.

  2. Phenylalanine Removal from Water by Fe3O4 Nanoparticles Functionalized with Two Different Surfactants

    Directory of Open Access Journals (Sweden)

    Ameneh Heidari

    2016-07-01

    Full Text Available In the present study, the application for the removal of phenylalanine by using two nano sorbents, namely, cetyltrimethylammonium bromide –Coated and BKC (benzal-conium chloride-Coated Fe3O4 nanoparticles was investigated. Solid-phase extraction (SPE and ultra violet–visible spectroscopy were used for studying the removal ability of each nano-sorbent in this study. Scanning Electron Microscopy, X-ray diffraction and Fourier infrared were used to characterize the synthesized magnetite nanoparticles. Batch adsorption studies were carried out to study the effect of various parameters, such as contact time, solution pH and concentration of phenylalanine. The equilibrium adsorption data of phenylalanine onto Fe3O4 nanoparticles (non-functionalized sample, cetyltrimethylammonium bromide -Coated and BKC -Coated were analyzed using Freundlich and Langmuir adsorption isotherms. The results indicated that adsorption of phenylalanine increased with increasing solution pH and maximum removal of phenylalanine was obtained at pH=9.0. Correlation coefficient were determined by analyzing each isotherm. It was found that the Freundlich equation showed better correlation with the experimental data than the Langmuir.

  3. Antibacterial effect of silk treated with silver and copper nanoparticles synthesized by pulsed laser ablation in distilled water

    Science.gov (United States)

    Baruah, Prahlad K.; Raman, Moghe A.; Chakrabartty, Ishani; Rangan, Latha; Sharma, Ashwini K.; Khare, Alika

    2018-05-01

    The antibacterial activity of three kinds of silks viz. Eri, Pat and Muga treated with silver and copper nanoparticles is reported in this paper. The nanoparticles have been synthesized by pulsed laser ablation of the respective metal targets in distilled water. Treatment of the silk pellets with the synthesized nanoparticles exhibited definite antibacterial activity whereas no such activity is observed in the untreated silk pellets.

  4. Characterization of ZnS nanoparticles synthesized by co-precipitation method

    International Nuclear Information System (INIS)

    Iranmanesh Parvaneh; Nourzpoor Mohsen; Saeednia Samira

    2015-01-01

    ZnS nanoparticles are prepared by homogeneous chemical co-precipitation method using EDTA as a stabilizer and capping agent. The structural, morphological, and optical properties of as-synthesized nanoparticles are investigated using x-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, ultraviolet-visible (UV-Vis) absorption, and photoluminescence spectroscopy. The x-ray diffraction pattern exhibits a zinc-blended crystal structure at room temperature. The average particle size of the nanoparticles from the scanning electron microscopy image is about 50 nm. The ultraviolet absorption spectrum shows the blue shift in the band gap due to the quantum confinement effect. The photoluminescence spectrum of ZnS nanoparticles shows a blue visible spectrum. (paper)

  5. PEG capped CaS nanoparticles synthesized by wet chemical co-precipitation method

    Science.gov (United States)

    Rekha, S.; Anila, E. I.

    2018-04-01

    Calcium sulfide (CaS) nanoparticles capped with polyethyleneglycol (PEG) were synthesized using wet chemical co-precipitation method. The structural and optical properties of the prepared sample were studied by X-ray diffractogram (XRD), transmission electron microscopy (TEM), diffuse reflectance spectrum (DRS) and photoluminescence (PL) spectrum. The structure of CaS nanoparticles is cubic as demonstrated by the X-ray powder diffraction (XRD) and selected area electron diffraction (SAED) analysis. TEMimage revealed the spherical morphology of the particles with diameter in the range 15-20 nm. The optical band gap of the prepared sample was determined from the DRS and its value was found to be 4.1 eV. The PL studies showed that the relative intensity of the PEG capped CaS nanoparticles was higher than that of uncapped CaS nanoparticles. The presence of various functional groups in the capped samples were examined by Fourier Transform Infrared (FTIR) spectroscopy.

  6. Visible light photocatalytic activities of ZnFe_2O_4/ZnO nanoparticles for the degradation of organic pollutants

    International Nuclear Information System (INIS)

    Rameshbabu, R.; Kumar, Niraj; Karthigeyan, A.; Neppolian, B.

    2016-01-01

    ZnFe_2O_4/ZnO nanoparticles have been synthesized by co-precipitation method using polyvinyl alcohol (PVA) as surfactant. The phase formation of synthesized products was systematically investigated from powder X-ray diffraction. Cubic ZnFe_2O_4 and hexagonal ZnO were identified in accordance with different molar concentrations of Fe"3"+ ions. The morphology and functionality were analyzed using field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and Fourier transform infrared (FTIR) spectroscopy. The optical properties and change in the band gap from UV to visible region upon increasing molar concentration of Fe"3"+ ions were analyzed from diffuse reflectance spectra (DRS). Superparamagnetic property was observed for synthesized ZnFe_2O_4/ZnO nanoparticles using vibrating sample magnetometer (VSM). The methylene blue and methyl orange were taken as model dyes to illustrate the photocatalytic activity of synthesized products under visible light irradiation. Maximum degradation of 99% for methyl orange (MO) was achieved by the use of 13 nm sized ZnFe_2O_4/ZnO nanoparticles as catalyst and a minutely less activity was observed for the methylene blue (MB) degradation (98%), when the photocatalytic processes were carried out for 5 h and 6 h, respectively. - Highlights: • Co-precipitation method is proposed to synthesize magnetic nanoparticles. • Modifications in the molar concentration lead to the shift in absorption edge. • Superparamagnetic property is demonstrated for the nanoparticles. • Two dye pollutants are utilized to demonstrate the photocatalytic activity.

  7. Visible light photocatalytic activities of ZnFe{sub 2}O{sub 4}/ZnO nanoparticles for the degradation of organic pollutants

    Energy Technology Data Exchange (ETDEWEB)

    Rameshbabu, R. [SRM Research Institute, SRM University, Kattankulathur, Kanchipuram 603203, Tamil Nadu (India); Kumar, Niraj [SRM Research Institute, SRM University, Kattankulathur, Kanchipuram 603203, Tamil Nadu (India); Centre for Materials Science and Nano Devices, Department of Physics and Nanotechnology, SRM University Kattankulathur, Kanchipuram 603203, Tamil Nadu (India); Karthigeyan, A., E-mail: karthigeyan.a@ktr.srmuniv.ac.in [Centre for Materials Science and Nano Devices, Department of Physics and Nanotechnology, SRM University Kattankulathur, Kanchipuram 603203, Tamil Nadu (India); Neppolian, B., E-mail: neppolian.b@res.srmuniv.ac.in [SRM Research Institute, SRM University, Kattankulathur, Kanchipuram 603203, Tamil Nadu (India)

    2016-09-15

    ZnFe{sub 2}O{sub 4}/ZnO nanoparticles have been synthesized by co-precipitation method using polyvinyl alcohol (PVA) as surfactant. The phase formation of synthesized products was systematically investigated from powder X-ray diffraction. Cubic ZnFe{sub 2}O{sub 4} and hexagonal ZnO were identified in accordance with different molar concentrations of Fe{sup 3+} ions. The morphology and functionality were analyzed using field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and Fourier transform infrared (FTIR) spectroscopy. The optical properties and change in the band gap from UV to visible region upon increasing molar concentration of Fe{sup 3+} ions were analyzed from diffuse reflectance spectra (DRS). Superparamagnetic property was observed for synthesized ZnFe{sub 2}O{sub 4}/ZnO nanoparticles using vibrating sample magnetometer (VSM). The methylene blue and methyl orange were taken as model dyes to illustrate the photocatalytic activity of synthesized products under visible light irradiation. Maximum degradation of 99% for methyl orange (MO) was achieved by the use of 13 nm sized ZnFe{sub 2}O{sub 4}/ZnO nanoparticles as catalyst and a minutely less activity was observed for the methylene blue (MB) degradation (98%), when the photocatalytic processes were carried out for 5 h and 6 h, respectively. - Highlights: • Co-precipitation method is proposed to synthesize magnetic nanoparticles. • Modifications in the molar concentration lead to the shift in absorption edge. • Superparamagnetic property is demonstrated for the nanoparticles. • Two dye pollutants are utilized to demonstrate the photocatalytic activity.

  8. Polyethyleneimine-modified superparamagnetic Fe3O4 nanoparticles: An efficient, reusable and water tolerance nanocatalyst

    International Nuclear Information System (INIS)

    Khoobi, Mehdi; Delshad, Tayebeh Modiri; Vosooghi, Mohsen; Alipour, Masoumeh; Hamadi, Hosein; Alipour, Eskandar; Hamedani, Majid Pirali; Sadat ebrahimi, Seyed Esmaeil; Safaei, Zahra; Foroumadi, Alireza; Shafiee, Abbas

    2015-01-01

    A novel magnetically separable catalyst was prepared based on surface modification of Fe 3 O 4 magnetic nanoparticle (MNPs) with polyethyleneimine (PEI) via covalent bonding. [3-(2,3-Epoxypropoxy)propyl]trimethoxysilane (EPO) was used as cross linker to bond PEI on the surface of MNPs with permanent stability in contrast to PEI coating via electrostatic interactions. The synthesized catalyst was characterized by Fourier transform infrared (FT-IR), thermogravimetric analysis (TGA), X-ray powder diffraction (XRD), transmission electron microscopy (TEM) and vibrating sample magnetometry (VSM). The catalyst show high efficiency for one-pot synthesis of 2-amino-3-cyano-4H-pyran derivatives via multi-component reaction (MCR). This procedure offers the advantages of green reaction media, high yield, short reaction time, easy purification of the products and simple recovery and reuse of the catalyst by simple magnetic decantation without significant loss of catalytic activity. - Graphical abstract: Covalently grafted polyethyleneimine on Fe 3 O 4 magnetic nanoparticles as easily reusable catalyst for the synthesis of various 4H-pyrans. - Highlights: • Polyethyleneimine modified Fe 3 O 4 via covalent bonding as a novel water tolerance catalyst. • The catalyst showed high efficiency for one-pot synthesis of 2-amino-3-cyano-4H-pyrans in water. • Catalysts could be easily recovered and reused for several times without a significant loss in their catalytic activity

  9. Reductive dechlorination of {gamma}-hexachlorocyclohexane using Fe-Pd bimetallic nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Nagpal, Varima; Bokare, Alok D. [Center for Nanobioscience, Agharkar Research Institute, G.G. Agarkar Road, Pune 411004, Maharashtra (India); Chikate, Rajeev C. [Department of Chemistry, MES Abasaheb Garware College, Karve Road, Pune 411004 (India); Rode, Chandrashekhar V. [Chemical Engineering and Process Development Division, National Chemical Laboratory, Pune 411008 (India); Paknikar, Kishore M., E-mail: paknikar@vsnl.com [Center for Nanobioscience, Agharkar Research Institute, G.G. Agarkar Road, Pune 411004, Maharashtra (India)

    2010-03-15

    Nanoscale Fe-Pd bimetallic particles were synthesized and used for degradation of lindane ({gamma}-hexachlorocyclohexane) in aqueous solution. Batch studies showed that 5 mg/L of lindane was completely dechlorinated within 5 min at a catalyst loading of 0.5 g/L and the degradation process followed first-order kinetics. GC-MS analysis in corroboration with GC-ECD results showed the presence of cyclohexane as the final degradation product. The proposed mechanism for the reductive dechlorination of lindane involves Fe corrosion-induced hydrogen atom transfer from the Pd surface. The enhanced degradation efficiency of Fe-Pd nanoparticles is attributed to: (1) high specific surface area of the nanoscale metal particles (60 m{sup 2}/g), manyfold greater that of commercial grade micro- or milli-scale iron particles ({approx}1.6 m{sup 2}/g); and, (2) increased catalytic reactivity due to the presence of Pd on the surface. Recycling and column studies showed that these nanoparticles exhibit efficient and sustained catalytic activity.

  10. Asymmetric dumbbell-shaped silver nanoparticles and spherical gold nanoparticles green-synthesized by mangosteen (Garcinia mangostana) pericarp waste extracts

    Science.gov (United States)

    Park, Ji Su; Ahn, Eun-Young; Park, Youmie

    2017-01-01

    Mangosteen (Garcinia mangostana) pericarp waste extract was used to synthesize gold and silver nanoparticles by a green strategy. The extract was both a reducing and stabilizing agent during synthesis. Phytochemical screening of the extract was conducted to obtain information regarding the presence/absence of primary and secondary metabolites in the extract. The in vitro antioxidant activity results demonstrated that the extract had excellent antioxidant activity, which was comparable to a standard (butylated hydroxy toluene). Spherical gold nanoparticles (gold nanoparticles green synthesized by mangosteen pericarp extract [GM-AuNPs]) with an average size of 15.37±3.99 to 44.20±16.99 nm were observed in high-resolution transmission electron microscopy (HR-TEM) images. Most interestingly, the silver nanoparticles (silver nanoparticles green synthesized by mangosteen pericarp extract [GM-AgNPs]) had asymmetric nanodumbbell shapes where one tail grew from a spherical head. The average head size was measured to be 13.65±5.07 to 31.08±3.99 nm from HR-TEM images. The hydrodynamic size of both nanoparticles tended to increase with increasing extract concentration. Large negative zeta potentials (−18.92 to −34.77 mV) suggested that each nanoparticle solution possessed excellent colloidal stability. The reaction yields were 99.7% for GM-AuNPs and 82.8% for GM-AgNPs, which were assessed by inductively coupled plasma optical emission spectroscopy. A high-resolution X-ray diffraction pattern confirmed the face-centered cubic structure of both nanoparticles. Based on phytochemical screening and Fourier transform infrared spectra, the hydroxyl functional groups of carbohydrates, flavonoids, glycosides, and phenolic compounds were most likely involved in a reduction reaction of gold or silver salts to their corresponding nanoparticles. The in vitro cytotoxicity (based on a water-soluble tetrazolium assay) demonstrated that GM-AgNPs were toxic to both A549 (a human lung

  11. A generalized diffusion model for growth of nanoparticles synthesized by colloidal methods.

    Science.gov (United States)

    Wen, Tianlong; Brush, Lucien N; Krishnan, Kannan M

    2014-04-01

    A nanoparticle growth model is developed to predict and guide the syntheses of monodisperse colloidal nanoparticles in the liquid phase. The model, without any a priori assumptions, is based on the Fick's law of diffusion, conservation of mass and the Gibbs-Thomson equation for crystal growth. In the limiting case, this model reduces to the same expression as the currently accepted model that requires the assumption of a diffusion layer around each nanoparticle. The present growth model bridges the two limiting cases of the previous model i.e. complete diffusion controlled and adsorption controlled growth of nanoparticles. Specifically, the results show that a monodispersion of nanoparticles can be obtained both with fast monomer diffusion and with surface reaction under conditions of small diffusivity to surface reaction constant ratio that results is growth 'focusing'. This comprehensive description of nanoparticle growth provides new insights and establishes the required conditions for fabricating monodisperse nanoparticles critical for a wide range of applications. Copyright © 2013 Elsevier Inc. All rights reserved.

  12. Gas Sensors Based on Tin Oxide Nanoparticles Synthesized from a Mini-Arc Plasma Source

    Directory of Open Access Journals (Sweden)

    Ganhua Lu

    2006-01-01

    Full Text Available Miniaturized gas sensors or electronic noses to rapidly detect and differentiate trace amount of chemical agents are extremely attractive. In this paper, we report on the fabrication and characterization of a functional tin oxide nanoparticle gas sensor. Tin oxide nanoparticles are first synthesized using a convenient and low-cost mini-arc plasma source. The nanoparticle size distribution is measured online using a scanning electrical mobility spectrometer (SEMS. The product nanoparticles are analyzed ex-situ by high resolution transmission electron microscopy (HRTEM for morphology and defects, energy dispersive X-ray (EDX spectroscopy for elemental composition, electron diffraction for crystal structure, and X-ray photoelectron spectroscopy (XPS for surface composition. Nonagglomerated rutile tin oxide (SnO2 nanoparticles as small as a few nm have been produced. Larger particles bear a core-shell structure with a metallic core and an oxide shell. The nanoparticles are then assembled onto an e-beam lithographically patterned interdigitated electrode using electrostatic force to fabricate the gas sensor. The nanoparticle sensor exhibits a fast response and a good sensitivity when exposed to 100 ppm ethanol vapor in air.

  13. One-pot hydrothermal synthesis of hollow Fe3O4 microspheres assembled with nanoparticles for lithium-ion battery anodes

    DEFF Research Database (Denmark)

    Liu, Yanguo; Wang, Xiaoliang; Ma, Wuming

    2016-01-01

    Hollow Fe3O4 microspheres assembled with nanoparticles were successfully synthesized without the addition of any templates or subsequent treatments. When used as the anode materials for lithium-ion battery (LIB), the products showed good lithium storage properties, demonstrating their promising...

  14. Fe{sub 3}C/Fe nanoparticles with urea: Synthesis, structure and magnetic properties

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xiaobai [College of Chemistry, Jilin University, Changchun, 130012 (China); School of Chemical and Pharmaceutical Engineering, Jilin Institute of Chemical Technology, Jilin, 132022 (China); Zhang, Daguang [Department of Orthopaedic Surgery, the First Hospital of Jilin University, Changchun, 130021 China (China); Ren, Xiaozhen; Gao, Jiajia [College of Chemistry, Jilin University, Changchun, 130012 (China); Han, Yu [Department of Chemistry, College of Science, Yanbian University, Yanji, 133002 China (China); Chen, Xiaodong [College of Chemistry, Jilin University, Changchun, 130012 (China); Shi, Zhan [State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University, Changchun, 130012 (China); Yang, Hua [College of Chemistry, Jilin University, Changchun, 130012 (China)

    2016-12-15

    Fe{sub 3}C/Fe nanocomposites were synthesized by a sol–gel method. Using urea as carbon source and reduce agent in the reaction process. The CTAB works as the surfactant and the bromine contained in CTAB plays a catalytic role. Appropriate choices of the amount of urea and CTAB, reaction temperature and time are very important to obtain high-quality of products. Above 650 °C, the precursor gel turned into the nanocomposites composed of iron carbide and iron. Their structures and magnetic properties are characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and vibrating sample magnetometry (VSM). The possible formation mechanism of as-prepared nanostructures is discussed. - Highlights: • The Fe{sub 3}C/Fe composites were synthetized by sol–gel method. • Their structure, magnetic properties are researched by XRD, VSM and TEM. • The possible formation mechanisms of the composites is discussed.

  15. Superior magnetic properties of Ni ferrite nanoparticles synthesized by capping agent-free one-step coprecipitation route at different pH values

    Science.gov (United States)

    Iranmanesh, P.; Tabatabai Yazdi, Sh.; Mehran, M.; Saeednia, S.

    2018-03-01

    In this work, well-dispersed nanoparticles of NiFe2O4 with diameters less than 10 nm and good crystallinity and excellent magnetic properties were synthesized via a simple one-step capping agent-free coprecipitation route from metal chlorides. The ammonia was used as the precipitating agent and also the solution basicity controller. The effect of pH value during the coprecipitation process was investigated by details through microstructural, optical and magnetic characterizations of the synthesized particles using X-ray diffraction, transmission electron microscopy, Fourier transform infrared and UV-vis spectroscopy, and vibrating sample magnetometer. The results showed that the particle size, departure from the inverse spinel structure, the band gap value and the magnetization of Ni ferrite samples increase with pH value from 9 to 11 indicating the more pronounced surface effects in the smaller nanoparticles.

  16. Facile synthesis of Sm-doped BiFeO{sub 3} nanoparticles for enhanced visible light photocatalytic performance

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Zijun; Chen, Da, E-mail: dchen_80@hotmail.com; Wang, Sen; Zhang, Ning; Qin, Laishun, E-mail: qinlaishun@cjlu.edu.cn; Huang, Yuexiang

    2017-06-15

    Highlights: • Effective Sm doping into BiFeO{sub 3} nanoparticles was obtained by a facile sol-gel route. • Band gap of Sm-doped BiFeO{sub 3} nanoparticles was regulated by the dopant concentration. • Sm-doped BiFeO{sub 3} nanoparticles exhibited superior photocatalytic activities. • The possible photocatalytic mechanism of Sm-doped BiFeO{sub 3} nanospheres was discussed. - Abstract: In this work, the effect of Sm doping on the structural and photocatalytic properties of BiFeO{sub 3} (BFO) was investigated. A series of Sm doped BFO nanoparticles containing different Sm dopant contents (Bi{sub (1−x)}Sm{sub x}FeO{sub 3}, x = 0.00, 0.01, 0.03, 0.05, 0.07, 0.10) were synthesized via a simple sol-gel route. It was revealed that Sm{sup 3+} ions were successfully doped into BFO nanoparticles, and the band gap value was gradually decreased when increasing Sm dopant concentration. The photocatalytic activity of Sm-doped BFO photocatalyst was significantly affected by the Sm doping content. Compared to pure BFO, the Sm-doped BFO samples exhibited much higher photocatalytic activity. The improved photocatalytic activity of Sm-doped BFO could be attributed to the enhanced visible light absorption and the efficient separation of photogenerated electrons and holes derived from Sm dopant trapping level in the Sm-doped BFO samples. In addition, the possible photocatalytic mechanism of Sm-doped BFO photocatalyst was also proposed.

  17. Antimicrobial, Antioxidant and Cytotoxic Activity of Silver Nanoparticles Synthesized by Leaf Extract of Erythrina suberosa (Roxb.).

    Science.gov (United States)

    Mohanta, Yugal K; Panda, Sujogya K; Jayabalan, Rasu; Sharma, Nanaocha; Bastia, Akshaya K; Mohanta, Tapan K

    2017-01-01

    In this experiment, biosynthesized silver nanoparticles (AgNPs) were synthesized using aqueous leaf extract of Erythrina suberosa (Roxb.). The biosynthesis of silver nanoparticle was continuously followed by UV-vis spectrophotometric analysis. The response of the phytoconstituents resides in E. suberusa during synthesis of stable AgNPs were analyzed by ATR- fourier-transform infrared spectroscopy. Further, the size, charge, and polydispersity nature of AgNPs were studied using dynamic light scattering spectroscopy. The morphology of the nanoparticles was determined by scanning electron microscopy. Current result shows core involvement of plant extracts containing glycosides, flavonoids, and phenolic compounds played a crucial role in the biosynthesis of AgNPs. The antimicrobial activities of silver nanoparticles were evaluated against different pathogenic bacterium and fungi. The antioxidant property was studied by radical scavenging (DPPH) assay and cytotoxic activity was evaluated against A-431 osteosarcoma cell line by MTT assay. The characteristics of the synthesized silver nanoparticles suggest their application as a potential antimicrobial and anticancer agent.

  18. Antibacterial Activity of Polyaniline Coated Silver Nanoparticles Synthesized from Piper Betle Leaves Extract.

    Science.gov (United States)

    Mamun Or Rashida, Md; Shafiul Islam, Md; Azizul Haque, Md; Arifur Rahman, Md; Tanvir Hossain, Md; Abdul Hamid, Md

    2016-01-01

    Plants or natural resources have been found to be a good alternative method for nanoparticles synthesis. In this study, polyaniline coated silver nanoparticles (AgNPs) synthesized from Piper betle leaves extract were investigated for their antibacterial activity. Silver nanoparticles were prepared from the reduction of silver nitrate and NaBH4 was used as reducing agent. Silver nanoparticles and extracts were mixed thoroughly and then coated by polyaniline. Prepared nanoparticles were characterized by Visual inspection, Ultraviolet-visible spectroscopy (UV), Fourier transform infrared Spectroscopy (FT-IR), Transmission Electron Microscopy (TEM) techniques. Antibacterial activities of the synthesized silver nanoparticles were tested against Staphylococcus aureus ATCC 25923, Salmonella typhi ATCC 14028, Escherichia coli ATCC 25922 and Pseudomonas aeruginosa ATCC 27853. UV-Vis spectrum of reaction mixture showed strong absorption peak with centering at 400 nm. The FT-IR results imply that Ag-NPs were successfully synthesized and capped with bio-compounds present in P. betle. TEM image showed that Ag-NPs formed were well dispersed with a spherical structures and particle size ranging from 10 to 30 nm. The result revealed that Ag-Extract NPs showed 32.78±0.64 mm zone of inhibition against S. aureus, whereas norfloxacin (positive control) showed maximum 32.15±0.40 mm zone of inhibition for S. aureus. Again, maximum zone of inhibition 29.55±0.45 mm was found for S. typhi, 27.12±0.38 mm for E. coli and 21.95±0.45 mm for P. aeruginosa. The results obtained by this study can't be directly extrapolated to human; so further studies should be undertaken to established the strong antimicrobial activity of Ag-Extract NPs for drug development program.

  19. Exosome purification based on PEG-coated Fe3O4 nanoparticles.

    Science.gov (United States)

    Chang, Ming; Chang, Yaw-Jen; Chao, Pei Yu; Yu, Qing

    2018-01-01

    Cancer cells secrete many exosomes, which facilitate metastasis and the later growth of cancer. For early cancer diagnosis, the detection of exosomes is a crucial step. Exosomes exist in biological fluid, such as blood, which contains various proteins. It is necessary to remove the proteins in the biological fluid to avoid test interference. This paper presented a novel method for exosome isolation using Fe3O4 magnetic nanoparticles (MNPs), which were synthesized using the chemical co-precipitation method and then coated with polyethylene glycol (PEG). The experimental results showed that the diameter of the PEG-coated Fe3O4 nanoparticles was about 20 nm, while an agglomerate of MNPs reached hundreds of nanometers in size. In the protein removal experiments, fetal bovine serum (FBS) was adopted as the analyte for bioassays of exosome purification. PEG-coated Fe3O4 MNPs reduced the protein concentration in FBS to 39.89% of the original solution. By observing a particle size distribution of 30~200 nm (the size range of various exosomes), the exosome concentrations were kept the same before and after purification. In the gel electrophoresis experiments, the bands of CD63 (~53 kDa) and CD9 (~22 kDa) revealed that exosomes existed in FBS as well as in the purified solution. However, the bands of the serum albumins (~66 kDa) and the various immunoglobulins (around 160 ~ 188 kDa) in the purified solution's lane explained that most proteins in FBS were removed by PEG-coated Fe3O4 MNPs. When purifying exosomes from serum, protein removal is critical for further exosome investigation. The proposed technique provides a simple and effective method to remove proteins in the serum using the PEG-coated Fe3O4 MNPs.

  20. Fe{sub 3}O{sub 4}/Salicylic acid nanoparticles behavior on chick CAM vasculature

    Energy Technology Data Exchange (ETDEWEB)

    Mihaiescu, Dan Eduard [' Politechnica' University of Bucharest, Faculty of Applied Chemistry and Materials Science (Romania); Buteica, Alice Sandra; Neamtu, Johny [University of Medicine and Pharmacy of Craiova, Faculty of Pharmacy (Romania); Istrati, Daniela [' Politechnica' University of Bucharest, Faculty of Applied Chemistry and Materials Science (Romania); Mindrila, Ion, E-mail: tutu0101@yahoo.com [University of Medicine and Pharmacy of Craiova, Department of Morphological Sciences (Romania)

    2013-08-15

    A modified ferrite co-precipitation synthesis was used to obtain core-shell Fe{sub 3}O{sub 4}/salicylic acid magnetic nanoparticles (Sa-MNP) with well-dispersed aqueous solution properties. The newly developed iron oxide nanoparticles properties were investigated with X-ray diffraction, Fourier transform infrared spectrometry, transmission electron microscopy, and laser light scattering for their characteristic establishment. The resulting Sa-MNPs have spherical morphology, homogenous size distribution around 60 nm (35 nm FWHM), and a 67 mV Zeta potential value (15.5 mV STDV). In vivo biocompatibility and intravascular behavior of the 60 nm diameter size range synthesized nanoparticles were evaluated on chick chorioallantoic membrane model. The results show a reversible and good controlled intravascular accumulation under static magnetic field, a low risk of embolisation with nanoparticle aggregates detached from venous intravascular nanoblocked areas, a persistent blocking of the arterioles and dependent capillaries network, a good circulating life time and biocompatibility. The beneficial effects of salicylic acid (SA) and in vivo demonstrated capacity of Sa-MNPs to cutoff regional vascular supply under static magnetic field control suggest a possible biomedical application of these MNPs in targeted cancer therapy through magnetic controlled blood flow nanoblocking mechanism.

  1. TEA controllable preparation of magnetite nanoparticles (Fe{sub 3}O{sub 4} NPs) with excellent magnetic properties

    Energy Technology Data Exchange (ETDEWEB)

    Han, Chengliang, E-mail: clhan@issp.ac.cn [Department of Chemical and Material Engineering, Hefei University, Hefei 230601 (China); Zhu, Dejie [State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002 (China); Wu, Hanzhao; Li, Yao; Cheng, Lu; Hu, Kunhong [Department of Chemical and Material Engineering, Hefei University, Hefei 230601 (China)

    2016-06-15

    A fast and controllable synthesis method for superparamagnetic magnetite nanoparticles (Fe{sub 3}O{sub 4} NPs) was developed in Fe(III)-triethanolamine (TEA) solution. The phase structure, morphology and particle size of the as-synthesized samples were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The results showed that the magnetic particles were pure Fe{sub 3}O{sub 4} with mean sizes of approximately 10 nm. The used TEA has key effects on the formation of well dispersing Fe{sub 3}O{sub 4} NPs. Vibrating sample magnetometer (VSM) result indicated that the as-obtained Fe{sub 3}O{sub 4} NPs exhibited superparamagnetic behavior and the saturation magnetization (M{sub s}) was about 70 emu/g, which had potential applications in magnetic science and technology. - Highlights: • The Fe{sub 3}O{sub 4} NPs are synthesized by a simple and low-cost hydrothermal approach. • The triethanolamine (TEA) played vital roles in the formation of Fe{sub 3}O{sub 4} NPs. • Our samples exhibited superparamagnetic and excellent dispersing properties in water.

  2. Electrochemical Hydrogen Storage in Facile Synthesized Co@N-Doped Carbon Nanoparticle Composites.

    Science.gov (United States)

    Zhou, Lina; Qu, Xiaosheng; Zheng, Dong; Tang, Haolin; Liu, Dan; Qu, Deyang; Xie, ZhiZhong; Li, Junsheng; Qu, Deyu

    2017-11-29

    A Co@nitrogen-doped carbon nanoparticle composite was synthesized via a facile molecular self-assembling procedure. The material was used as the host for the electrochemical storage of hydrogen. The hydrogen storage capacity of the material was over 300 mAh g -1 at a rate of 100 mAg -1 . It also exhibited superior stability for storage of hydrogen, high rate capability, and good cyclic life. Hybridizing metallic cobalt nanoparticle with nitrogen-doped mesoporous carbon is found to be a good approach for the electrochemical storage of hydrogen.

  3. SWAXS investigations on diffuse boundary nanostructures of metallic nanoparticles synthesized by electrical discharges

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Xiaoai, E-mail: xiaoai.guo@kit.edu; Gutsche, Alexander; Nirschl, Hermann [Karlsruhe Institute of Technology, Institute for Mechanical Process Engineering and Mechanics (Germany)

    2013-11-15

    Metallic nanoparticles have attracted a particular interest in scientific research and industrial applications due to their unique size-dependent physical and chemical properties. An eco-friendly and cost-effective synthesis method called electrical discharge enables large scale production of metallic nanoparticles. Systematic investigations of such synthesized metallic nanoparticles help to optimize the synthesis process and improve the product quality. In this work, for the first time we have investigated the diffuse interfacial boundary nanostructures of the metallic nanoparticles, which were synthesized under different conditions by electrical glow and arc discharges in the carrier gas, by means of a small- and wide-angle X-ray scattering (SWAXS) technique using a laboratory X-ray source. Meanwhile, this unique SWAXS technique allows simultaneous study of the primary particle size, morphology, and crystallinity. The metallic nanoparticles (copper and nickel) under investigation cover a size range of 10–80 nm, and the determined thickness of the diffuse boundary nanostructured layer of metallic nanoparticles is in the range of 1–3 nm. The experimental results obtained by SWAXS were compared to the TEM/EDX observation and the XRD reference patterns from RRUFF database, and a good agreement was found. Our SWAXS investigations indicated that the existence of a diffuse nanostructured solid layer on the synthesized metallic nanoparticle surface causes a negative deviation of the scattering intensity (Ι∝q{sup -α}, α>4) from Porod’s law which corresponds to the case of ideal two-phase particle systems with sharp boundaries (Ι∝q{sup -α}, α=4) . This implies that the electron density profile is not sharp but changes gradually between two phases, and hence the exponent α is greater than four. Two electron density profile models, sigmoidal electron-density gradient model and linear electron-density gradient model, have been taken into account in

  4. Hydrothermal synthesis, off-axis electron holography and magnetic properties of Fe3O4 nanoparticles

    DEFF Research Database (Denmark)

    Almeida, Trevor P.; Muxworthy, Adrian R.; Williams, Wyn

    2014-01-01

    The hydrothermal synthesis of Fe3O4 nanoparticles (NPs) (<50 nm) from mixed FeCl3 / FeCl2 precursor solution at pH ~ 12 has been confirmed using complementary characterisation techniques of transmission electron microscopy and X-ray diffractometry. Off-axis electron holography allowed for visuali......The hydrothermal synthesis of Fe3O4 nanoparticles (NPs) (holography allowed...

  5. Investigation of microstructural and optical properties of La0.8Ca0.2FeO3 nanostructure synthesized via gel combustion method

    Science.gov (United States)

    Naseem, Swaleha; Ali, S. Asad; Khan, Wasi; Khan, Shakeel

    2018-05-01

    Ca substituted LaFeO3 orthoferrite nanostructure perovskite has been synthesized by gel combustion method using citric acid as a fuel. The structural and optical properties were investigated by various tools. The structural analysis through Rietveld refinement of the XRD data revealed single phase of orthorhombic structure in R-3c space group of the sample without presence of any other impurity phase. Scanning electron microscopy (SEM) image exhibits non-uniform distribution of the nanoparticles in agglomerated form. The purity of the sample and stoichiometric ratio of the elements were established through energy dispersive x-ray spectroscopy (EDS). FTIR spectroscopy measurement predicts the presence of various band relation of the chemical species of Ca with LaFeO3. Optical properties were explored through UV-visible absorption spectroscopy that showed absorption edge at 347 nm and energy band gap was estimated as 3.47eV using Tauc's relation.

  6. FeCrO Nanoparticles as Anode Catalyst for Ethane Proton Conducting Fuel Cell Reactors to Coproduce Ethylene and Electricity

    Directory of Open Access Journals (Sweden)

    Jian-Hui Li

    2011-01-01

    Full Text Available Ethylene and electrical power are cogenerated in fuel cell reactors with FeCr2O4 nanoparticles as anode catalyst, La0.7Sr0.3FeO3- (LSF as cathode material, and BaCe0.7Zr0.1Y0.2O3- (BCZY perovskite oxide as proton-conducting ceramic electrolyte. FeCr2O4, BCZY and LSF are synthesized by a sol-gel combustion method. The power density increases from 70 to 240 mW cm−2, and the ethylene yield increases from about 14.1% to 39.7% when the operating temperature of the proton-conducting fuel cell reactor increases from 650∘C to 750∘C. The FeCr2O4 anode catalyst exhibits better catalytic performance than nanosized Cr2O3 anode catalyst.

  7. Examination of the magnetic hyperthermia and other magnetic properties of CoFe2O4@MgFe2O4 nanoparticles using external field Mössbauer spectroscopy

    Science.gov (United States)

    Park, Jeongho; Choi, Hyunkyung; Kim, Sam Jin; Kim, Chul Sung

    2018-05-01

    CoFe2O4@MgFe2O4 core/shell nanoparticles were synthesized by high temperature thermal decomposition with seed-mediated growth. The crystal structure and magnetic properties of the nanoparticles were investigated using X-ray diffractometry (XRD), vibrating sample magnetometry (VSM), and Mössbauer spectrometry. The magnetic hyperthermia properties were investigated using a MagneTherm device. Analysis of the XRD patterns showed that CoFe2O4@MgFe2O4 had a cubic spinel crystal structure with space group Fd-3m and a lattice constant (a0) of 8.3686 Å. The size and morphology of the CoFe2O4@MgFe2O4 nanoparticles were confirmed by HR-TEM. The VSM measurements showed that the saturation magnetization (MS) of CoFe2O4@MgFe2O4 was 77.9 emu/g. The self-heating temperature of CoFe2O4@MgFe2O4 was 37.8 °C at 112 kHz and 250 Oe. The CoFe2O4@MgFe2O4 core/shell nanoparticles showed the largest saturation magnetization value, while their magnetic hyperthermia properties were between those of the CoFe2O4 and MgFe2O4 nanoparticles. In order to investigate the hyperfine interactions of CoFe2O4, MgFe2O4, and CoFe2O4@MgFe2O4, we performed Mössbauer spectrometry at various temperatures. In addition, Mössbauer spectrometry of CoFe2O4@MgFe2O4 was performed at 4.2 K with applied fields of 0-4.5 T, and the results were analyzed with sextets for the tetrahedral A-site and sextets for the octahedral B-site.

  8. Preparation and Characterization of Chitosan-coated Fe3O4 Nanoparticles using Ex-Situ Co-Precipitation Method and Tripolyphosphate/Sulphate as Dual Crosslinkers

    Science.gov (United States)

    Wulandari, Ika O.; Mardila, Vita T.; Santjojo, D. J. Djoko H.; Sabarudin, Akhmad

    2018-01-01

    The unique properties of nanomaterial provide great opportunities to develop in several fields. Several types of nanoparticles have been proven beneficial for biomedical and therapeutic agent development. Particularly for clinical use, nanoparticles must be biocompatible and non-toxic. Iron oxide nanoparticles consist of either magnetite (Fe3O4) or maghemite (γ-Fe2O3) was eligible to use for in vivo application including targeting drug delivery. Due to their distinct properties, these nanoparticles could be directed to the specific target under external magnetic field. However, nanoparticles have a tendency to form agglomeration. Therefore, surface modification was required to reduce the agglomeration. In this study, nanoparticles of Fe3O4 were produced and coated by biomaterial (chitosan) using ex-situ co-precipitation method. Nanoparticles of Fe3O4 were synthesized by adding ammonia water into iron ferric and ferrous solution. Synthesis process of Fe3O4 was conducted prior to adding chitosan. Chitosan was then cross-linked by a combination of tripolyphosphate/sulphate. The different composition ratio and crosslinking time provide the different physical and magnetic characteristics of nanoparticles. Particle and crystallite size was determined by using Scanning Electron Microscopy (SEM) and X-Ray Diffraction (XRD) respectively, whereas magnetic characteristic was determined by Electron Spin Resonance (ESR). The results showed that the ratio enhancement between chitosan: Fe3O4 increase the particle size, while decreased the crystallite size. Morphology and particle size were influenced by the ratio of crosslinkers. It was found that the higher tripolyphosphate content was contributed to the small size and more spherical morphology. In addition, the influence of crosslinking time toward crystallite size was determined by altering stirring time. The longer duration of crosslinking time, provide the larger crystallite size of chitosan-Fe3O4. There was an interesting

  9. Biogenic silver nanoparticles synthesized with rhamnogalacturonan gum: Antibacterial activity, cytotoxicity and its mode of action

    Directory of Open Access Journals (Sweden)

    Aruna Jyothi Kora

    2018-03-01

    Full Text Available Silver nanoparticles synthesized from gum kondagogu (5 nm were used to evaluate the antibacterial activity against Gram-positive and Gram-negative bacteria. To decipher the mode of antibacterial action of nanoparticles, a comprehensive study was carried out employing a variety of susceptibility assays: micro-broth dilution, antibiofilm activity, growth kinetics, cytoplasmic content leakage, membrane permeabilization, etc. The production of reactive oxygen species (ROS and cell surface damage during bacterial nanoparticle interaction were also demonstrated using dichlorodihydrofluorescein diacetate, N-acetylcysteine; and scanning electron microscopy and energy dispersive X-ray spectra. Further, the biocompatibility with HeLa cell line was also evaluated. Compared to earlier reports, the minimum inhibitory concentration values were lower by 3.2- and 16-folds for Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli strains, respectively. The minimum bactericidal concentration values were lower by 4 and 50-folds. Thus, the biogenic silver nanoparticles were found to be more potent bactericidal agents in terms of concentration. The nanoparticles exhibited significant antibiofilm activity against test strains at 2 μg mL−1, which can have implications in the treatment of drug resistant bacterial infections caused by biofilms. Growth curve in nanoparticle supplemented indicated a faster inhibition in Gram-negative bacteria as compared to Gram-positive. Treatment with nanoparticles caused cytoplasmic content leakage and membrane permeabilization in a dose dependent manner, an evidence for membrane damage. The observations noted in our study substantiated the association of ROS and membrane damage in the antibacterial action of silver nanoparticles. The promising antibacterial activity enables these nanoparticles as potential bactericidal material for various environmental and biomedical applications.

  10. Bias Voltage-Dependent Impedance Spectroscopy Analysis of Hydrothermally Synthesized ZnS Nanoparticles

    Science.gov (United States)

    Dey, Arka; Dhar, Joydeep; Sil, Sayantan; Jana, Rajkumar; Ray, Partha Pratim

    2018-04-01

    In this report, bias voltage-dependent dielectric and electron transport properties of ZnS nanoparticles were discussed. ZnS nanoparticles were synthesized by introducing a modified hydrothermal process. The powder XRD pattern indicates the phase purity, and field emission scanning electron microscope image demonstrates the morphology of the synthesized sample. The optical band gap energy (E g = 4.2 eV) from UV measurement explores semiconductor behavior of the synthesized material. The electrical properties were performed at room temperature using complex impedance spectroscopy (CIS) technique as a function of frequency (40 Hz-10 MHz) under different forward dc bias voltages (0-1 V). The CIS analysis demonstrates the contribution of bulk resistance in conduction mechanism and its dependency on forward dc bias voltages. The imaginary part of the impedance versus frequency curve exhibits the existence of relaxation peak which shifts with increasing dc forward bias voltages. The dc bias voltage-dependent ac and dc conductivity of the synthesized ZnS was studied on thin film structure. A possible hopping mechanism for electrical transport processes in the system was investigated. Finally, it is worth to mention that this analysis of bias voltage-dependent dielectric and transport properties of as-synthesized ZnS showed excellent properties for emerging energy applications.

  11. Realizing high magnetic moments in fcc Fe nanoparticles through atomic structure stretch

    International Nuclear Information System (INIS)

    Baker, S H; Roy, M; Thornton, S C; Binns, C

    2012-01-01

    We describe the realization of a high moment state in fcc Fe nanoparticles through a controlled change in their atomic structure. Embedding Fe nanoparticles in a Cu 1-x Au x matrix causes their atomic structure to switch from bcc to fcc. Extended x-ray absorption fine structure (EXAFS) measurements show that the structure in both the matrix and the Fe nanoparticles expands as the amount of Au in the matrix is increased, with the data indicating a tetragonal stretch in the Fe nanoparticles. The samples were prepared directly from the gas phase by co-deposition, using a gas aggregation source and MBE-type sources respectively for the nanoparticle and matrix materials. The structure change in the Fe nanoparticles is accompanied by a sharp increase in atomic magnetic moment, ultimately to values of ∼2.5 ± 0.3 μ B /atom. (paper)

  12. Ferromagnetic resonance on oxideless magnetic Fe and FeRh nanoparticles; Ferromagnetische Resonanz an oxidfreien magnetischen Fe und FeRh Nanopartikeln

    Energy Technology Data Exchange (ETDEWEB)

    Trunova, Anastasia

    2009-05-25

    This work is dedicated to investigations of structural and magnetic properties of the colloidal Fe/Fe{sub x}O{sub y} nanocubes (13 nm) and the Fe{sub x}Rh{sub 100-x} core/shell nanoparticles (2 nm). As compared with other works, where the measurements on oxidized nanoparticles were carried out, we additionally performed investigations on nanoparticles in an oxide free state. In order to make the measurements on oxide free particles possible, oxygen- and hydrogenplasma was used to remove the ligands and reduce the oxide shell of the Fe nanocubes. The oxide free Fe nanocubes were covered with a Ag/Pt protective coating to prevent them from new oxidation. This method allowed carrying out the magnetic measurements on oxide free Fe nanocubes. Micromagnetic simulations as well as simulations of the high frequency susceptibility were used for the data analysing. It was found that both the g-factor g=2.09{+-}0.01 and the anisotropy constant K{sub 4}=(4.8{+-}0.5).10{sup 4} J/m{sup 3} coincide with that of bulk iron. However, the saturation magnetization M{sub S}(5 K)=(1.2{+-}0.12).10{sup 6} A/m differs from the bulk value by 30%. The reduction by 30% compared to the bulk value in the case of nanoparticles may be caused by the following possible reasons: a) the presence of inner oxide layer (approx. 10 at.%) that cannot be reduced; b) the anti-parallel order between magnetic moments of iron core and magnetic moments of antiferomagnetic iron oxide; c) some structural changes of the surface after plasma treatment. The obtained damping parameter {alpha}=0.03{+-}0.005 is ten times larger than that of the Fe layers as it is known for nanoparticles systems in general. The core/shell Fe{sub x}Rh{sub 100-x} nanoparticles (x=80,50) were produced under Ar-atmosphere and were sealed into a quartz tube to prevent oxidation. The analysis of g-factors shows that the value for the FePh nanoparticles with Fe-rich core is larger (g=2.08{+-}0.01) than that for the nanoparticles with Rh

  13. Magnetically separable core–shell ZnFe_2O_4@ZnO nanoparticles for visible light photodegradation of methyl orange

    International Nuclear Information System (INIS)

    Kulkarni, Suresh D.; Kumbar, Sagar; Menon, Samvit G.; Choudhari, K.S.; Santhosh, C.

    2016-01-01

    Highlights: • Phase pure, magnetic ZnFe_2O_4@ZnO nanoparticles synthesized with excellent yield. • ZnFe_2O_4@ZnO displayed higher UV photocatalytic efficiency than ZnO nanoparticles. • First report on visible light photodegradation of methyl orange by ZnFe_2O_4@ZnO. • Excellent reusability of ZnFe_2O_4@ZnO nanoparticles observed for azo dye removal. - Abstract: Visible light photodegradation of aqueous methyl orange using magnetically separable core–shell ZnFe_2O_4@ZnO nanoparticles is reported. A combination of low temperature (190 °C) microwave synthesis and hydrothermal method were used to prepare phase pure material with excellent yield (95%). The magnetic separability, surface area of 41 m"2/g and visible light absorption make ZnFe_2O_4@ZnO nanoparticles a good solar photocatalyst. ZnFe_2O_4@ZnO displayed greater UV photocatalytic efficiency than ZnO owing to the generation of large number of electron-hole pairs. Visible light photodegradation of MO using ZnFe_2O_4@ZnO nanoparticles is reported for the first time. Higher first order rate constants under both UV and visible light for core-shell nanoparticles suggested their superiority over its individual oxides. The ZnFe_2O_4@ZnO showed excellent reusability with high photocatalytic efficiencies suggesting its suitability for solar photocatalytic applications.

  14. Preparation and evaluation of magnetic nanocomposite fibers containing α″-Fe16N2 and α-Fe nanoparticles in polyvinylpyrrolidone via magneto-electrospinning

    Science.gov (United States)

    Kartikowati, Christina W.; Suhendi, Asep; Zulhijah, Rizka; Ogi, Takashi; Iwaki, Toru; Okuyama, Kikuo

    2016-01-01

    Two kinds of ferromagnetic nanocomposite fiber comprising α″-Fe16N2 and α-Fe nanoparticles (NPs), which have the highest magnetic moments as hard and soft magnetic materials, respectively, embedded in polyvinylpyrrolidone (PVP) have been synthesized via the magneto-electrospinning method. Both α″-Fe16N2 and α-Fe were single-domain core-shell NPs with an average outer diameter of 50 nm and Al2O3 as the shell. Ferrofluid precursors used for the electrospinning were prepared by dispersing these NPs in a PVP-toluene-methanol solution. The results show that applying the magnetic field in the same direction as the electric field resulted in smaller and more uniform fiber diameters. Nanocomposite fibers containing α″-Fe16N2 had smaller diameters than those containing α-Fe NPs. These magnetic-field effects on the fiber formation were explained by referring to the kinetic energy of the moving jet in the electrospinning process. In addition, magnetic hysteresis curves showed an enhancement of the magnetic coercivity (H c) and remanence (M r) by 22.9% and 22.25%, respectively. These results imply a promising possibility of constructing bulk magnetic materials using α″-Fe16N2 NPs, which furthermore reveals attractive features for many other magnetic applications, such as magnetic sensors.

  15. Monodisperse magnetite (Fe{sub 3}O{sub 4}) nanoparticles modified with water soluble polymers for the diagnosis of breast cancer by MRI method

    Energy Technology Data Exchange (ETDEWEB)

    Rezayan, Ali Hossein, E-mail: ahrezayan@ut.ac.ir [Department of Life Science Engineering, Faculty of New Sciences and Technologies, University of Tehran, Tehran (Iran, Islamic Republic of); Mousavi, Majid [Department of Life Science Engineering, Faculty of New Sciences and Technologies, University of Tehran, Tehran (Iran, Islamic Republic of); Kheirjou, Somayyeh [Department of Chemistry, Sharif University of Technology, Tehran (Iran, Islamic Republic of); Amoabediny, Ghasem [School of Chemical Engineering, College of Engineering, University of Tehran, Tehran (Iran, Islamic Republic of); Ardestani, Mehdi Shafiee [Department of Pharmacy, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Mohammadnejad, Javad [Department of Life Science Engineering, Faculty of New Sciences and Technologies, University of Tehran, Tehran (Iran, Islamic Republic of)

    2016-12-15

    In this study, magnetic nanoparticles (MNPs) were synthesized via co-precipitation method. To enhance the biocompatibility and colloidal stability of the synthesized nanoparticles, they were modified with carboxyl functionalized PEG via dopamine (DPA) linker. Both modified and unmodified Fe{sub 3}O{sub 4} nanoparticles exhibited super paramagnetic behavior (particle size below 20 nm). The saturation magnetization (Ms) of PEGdiacid-modified Fe{sub 3}O{sub 4} was 45 emu/g, which was less than the unmodified Fe{sub 3}O{sub 4} nanoparticles (70 emu/g). This difference indicated that PEGdiacid polymer was immobilized on the surface of Fe{sub 3}O{sub 4} nanoparticles successfully. To evaluate the efficiency of the resulting nanoparticles as contrast agents for magnetic resonance imaging (MRI), different concentration of MNPs and different value of echo time TE were investigated. The results showed that by increasing the concentration of the nanoparticles, transverse relaxation time (T{sub 2}) decreased, which subsequently resulted in MR signal enhancement. T{sub 2}-weighted MR images of the different concentration of MNPs in different value of echo time TE indicated that MR signal intensity increased with increase in TE value up to 66 and then remained constant. The cytotoxicity effect of the modified and unmodified nanoparticles was evaluated in three different concentrations (12, 60 and 312 mg l{sup −1}) on MDA-MB-231 cancer cells for 24 and 48 h. In both tested time (24 and 48 h) for all three samples, the modified nanoparticles had long life time than unmodified nanoparticles. Cellular uptake of modified MNPs was 80% and reduced to 9% by the unmodified MNPs. - Highlights: • Magnetic nanoparticles (MNPs) were synthesized via co-precipitation method. • MNPs were modified with carboxyl functionalized PEG via dopamine (DPA) linker. • Modified and unmodified Fe{sub 3}O{sub 4} nanoparticles exhibited super paramagnetic behavior. • T{sub 2} decrease as MNPs

  16. Optical Properties and Microstructure of Silver-Copper Nanoparticles Synthesized by Pulsed Laser Deposition

    Science.gov (United States)

    Hirai, Makoto; Kumar, Ashok

    2007-12-01

    Utilizing a pulsed laser deposition (PLD) method, silver-copper (Ag-Cu) nanoparticles have been synthesized by changing the surface area ratio of the target ( S R = S Cu/( S Ag + S Cu)) from 0 to 30%. The peak absorption attributed to surface plasmon resonance (SPR) increased when increasing S R up to 15%, above which it decreased. The peak shifts seem to be induced by the changes in the conductivity and morphology of the Ag-Cu nanoparticles. Additionally, the interplanar spacings of the Ag-Cu nanoparticles prepared at S R = 15% corresponded to the Ag {111}, {200}, {220}, and Cu {111} planes. However, since the interplanar spacings attributed to the Cu {200} and {220} planes were not detected, the Ag-Cu nanoparticles were believed to possess a lattice constant ( a) close not to the Cu phase ( a = 3.615 Å) but to the Ag phase ( a = 4.086 Å). Moreover, confirming the presence of Cu atoms in the nanoparticles using energy dispersive X-ray (EDX) spectra, Ag-Cu nanoparticles may be a solid solution in which Cu atoms partially replace Ag atoms in the fcc structure.

  17. Sonochemically synthesized MnO2 nanoparticles as electrode material for supercapacitors.

    Science.gov (United States)

    Gnana Sundara Raj, Balasubramaniam; Asiri, Abdullah M; Qusti, Abdullah H; Wu, Jerry J; Anandan, Sambandam

    2014-11-01

    In this study, manganese oxide (MnO2) nanoparticles were synthesized by sonochemical reduction of KMnO4 using polyethylene glycol (PEG) as a reducing agent as well as structure directing agent under room temperature in short duration of time and characterized by powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Scanning electron microscope (SEM), Transmission electron microscopy (TEM) and Brunauer-Emmett-Teller (BET) analysis. A supercapacitor device constructed using the ultrasonically-synthesized MnO2 nanoparticles showed maximum specific capacitance (SC) of 282Fg(-1) in the presence of 1M Ca(NO3)2 as an electrolyte at a current density of 0.5mAcm(-2) in the potential range from 0.0 to 1.0V and about 78% of specific capacitance was retained even after 1000 cycles indicating its high electrochemical stability. Copyright © 2013 Elsevier B.V. All rights reserved.

  18. Kinetics of oxygen adsorption on ZnS nanoparticles synthesized by precipitation process

    Directory of Open Access Journals (Sweden)

    Ahmadi Reza

    2016-06-01

    Full Text Available ZnS nanoparticles were synthesized through a one-step precipitation process. Effect of time and temperature on the formation reaction was investigated. The synthesized samples were characterized by X-ray diffraction (XRD, ultraviolet (UV visible absorption and photoluminescence (PL spectrophotometry. Based on XRD and UV-Vis data, the particles produced at 70 °C had a mean particle size of about 5 nm. Increasing time and temperature of the synthesis reaction resulted in photoluminescence intensification. PL spectroscopy helped understanding the adsorption kinetics of oxygen on ZnS nanoparticles during the precipitation synthesis process. Fabrication of ZnS structures with appropriate oxygen adsorption capacity was suggested as a means of PL emission intensity control.

  19. Purification of simulated waste water using green synthesized silver nanoparticles of Piliostigma thonningii aqueous leave extract

    Science.gov (United States)

    Shittu, K. O.; Ihebunna, O.

    2017-12-01

    Synthesis of nanoparticles from various biological systems has been reported, but among all such systems, biosynthesis of nanoparticles from plants is considered the most suitable method. The use of plant material not only makes the process eco-friendly, but also the abundance makes it more economical. The aim of this study was to biologically synthesize silver nanoparticle using Piliostigma thonningii aqueous leaf extract and applied in the purification of laboratory stimulated waste with optimization using the different conditions of silver nanoparticle production such as time, temperature, pH, concentration of silver nitrate and volume of the aqueous extract. The biosynthesized silver nanoparticles were characterized by UV-visible spectrophotometry, nanosizer, energy dispersive x-ray analysis (EDX), transmission electron microscopy (TEM) and Fourier transform infrared (FTIR) spectroscopy. The time intervals for the reaction with aqueous silver nitrate solution shows an increase in the absorbance with time and became constant giving a maximum absorbance at 415 nm at 60 min of incubation. The pH of 6.5, temperature 65 °C, 1.25 mM of silver nitrate and 5 ml of plant extract was the best condition with maximum absorbance. The results from nanosizer, UV-vis and TEM suggested the biosynthesis silver nanoparticle to be spherical ranging from 50 nm to 114 nm. The EDX confirmed the elemental synthesis of silver at 2.60 keV and FTIR suggested the capping agent to be hydroxyl (OH) group with -C=C stretching vibrations. The synthesized silver nanoparticle also shows heavy metal removal activity in laboratory simulated waste water. The safety toxicity studies show no significant difference between the orally administered silver nanoparticles treated water group and control group, while the histopathological studies show well preserved hepatic architecture for the orally administered silver nanoparticle treated waste water group when compared with the control

  20. Structural and magnetic characterization of Fe2CrSi Heusler alloy nanoparticles as spin injectors and spin based sensors

    Science.gov (United States)

    Saravanan, G.; Asvini, V.; Kalaiezhily, R. K.; Parveen, I. Mubeena; Ravichandran, K.

    2018-05-01

    Half-metallic ferromagnetic [HMF] nanoparticles are of considerable interest in spintronics applications due to their potential use as a highly spin polarized current source. HMF exhibits a semiconductor in one spin band at the Fermi level Ef and at the other spin band they poses strong metallic nature which shows 100 % spin polarization at Ef. Fe based full Heusler alloys are primary interest due to high Curie temperature. Fe2CrSi Heusler alloys are synthesized using metallic powders of Fe, Cr and Si by mechanical alloying method. X-Ray diffractions studies were performed to analyze the structural details of Fe2CrSi nanoparticles with High resolution scanning electron microscope (HRSEM) studies for the morphological details of nanoparticles and magnetic properties were studied using Vibrating sample magnetometer (VSM). XRD Data analysis conforms the Heusler alloy phase showing the existence of L21 structure. Magnetic properties are measured for synthesized samples exhibiting a soft magnetic property possessing low coercivity (HC = 60.5 Oe) and saturation magnetic moment of Fe2CrSi is 3.16 µB, which is significantly higher than the ideal value of 2 µB from the Slater-Pauling rule due to room temperature measurement. The change in magnetic properties are half-metallic nature of Fe2CrSi is due to the shift of the Fermi level with respect to the gap were can be used as spin sensors and spin injectors in magnetic random access memories and other spin dependent devices.

  1. Green synthesis and antimicrobial activity of monodisperse silver nanoparticles synthesized using Ginkgo Biloba leaf extract

    Energy Technology Data Exchange (ETDEWEB)

    Ren, Yan-yu [School of Food and Biological Engineering, Shaanxi University of Science & Technology, Xi' an 710021 (China); Yang, Hui, E-mail: 549456369@qq.com [School of Food and Biological Engineering, Shaanxi University of Science & Technology, Xi' an 710021 (China); Wang, Tao [School of Food and Biological Engineering, Shaanxi University of Science & Technology, Xi' an 710021 (China); Wang, Chuang [Department of Highway & Bridge, Shaanxi Railway Institute, Weinan 714000 (China)

    2016-11-25

    Various parts of plants can be used as a raw material for the synthesis of nanoparticles, which is eco-friendly way and does not involve any harmful chemicals. In this project, Ginkgo biloba leaf, an abundantly available medicinal plant in China, was for the first time adopted as a reducing and stabilizing agent to synthesize smaller sized and stable silver nanoparticles (AgNPs). To improve the quality of AgNPs, the reduction was accelerated by changing the concentrations of initial Ag{sup +} (0.02, 0.04, 0.06 and 0.08 mol/L) of the reaction mixture consisting of silver nitrate solution (AgNO{sub 3}) and Ginkgo biloba leaf extract. At pH = 8 and lower AgNO{sub 3} concentration (0.02 mol/L), a colloid consisting of well-dispersed spherical nanoparticles was obtained. The synthesized nanocrystals were successfully characterized by UV–vis and XRD. TEM images revealed the size of the spherical AgNPs ranged between 10–16 nm. FTIR analysis revealed that biological macromolecules with groups of −NH{sub 2}, −OH, and others were distributed on the surface of the nanoparticles. The biosynthesized AgNPs exhibited good antibacterial activities against gram-negative bacteria and gram-positive bacteria. Compared to traditional chemical methods, Ginkgo biloba leaf extract provides an easy green synthetical way. It is anticipated that the biosynthesized AgNPs can be used in areas such as cosmetics, foods and medical applications. - Highlights: • Monodisperse silver nanoparticles were first prepared by a green synthetical way through Ginkgo Biloba leaf extract. • The synthesized AgNPs is of high crystallinity, stable and good dispersion with smaller sizes between 10–16 nm. • The achieved AgNPs exhibits good antibacterial activities. • The biosynthesis method is advantageous for its cost effectiveness, availability, portability, nontoxic and environmentally benign.

  2. Green synthesis and antimicrobial activity of monodisperse silver nanoparticles synthesized using Ginkgo Biloba leaf extract

    International Nuclear Information System (INIS)

    Ren, Yan-yu; Yang, Hui; Wang, Tao; Wang, Chuang

    2016-01-01

    Various parts of plants can be used as a raw material for the synthesis of nanoparticles, which is eco-friendly way and does not involve any harmful chemicals. In this project, Ginkgo biloba leaf, an abundantly available medicinal plant in China, was for the first time adopted as a reducing and stabilizing agent to synthesize smaller sized and stable silver nanoparticles (AgNPs). To improve the quality of AgNPs, the reduction was accelerated by changing the concentrations of initial Ag + (0.02, 0.04, 0.06 and 0.08 mol/L) of the reaction mixture consisting of silver nitrate solution (AgNO 3 ) and Ginkgo biloba leaf extract. At pH = 8 and lower AgNO 3 concentration (0.02 mol/L), a colloid consisting of well-dispersed spherical nanoparticles was obtained. The synthesized nanocrystals were successfully characterized by UV–vis and XRD. TEM images revealed the size of the spherical AgNPs ranged between 10–16 nm. FTIR analysis revealed that biological macromolecules with groups of −NH 2 , −OH, and others were distributed on the surface of the nanoparticles. The biosynthesized AgNPs exhibited good antibacterial activities against gram-negative bacteria and gram-positive bacteria. Compared to traditional chemical methods, Ginkgo biloba leaf extract provides an easy green synthetical way. It is anticipated that the biosynthesized AgNPs can be used in areas such as cosmetics, foods and medical applications. - Highlights: • Monodisperse silver nanoparticles were first prepared by a green synthetical way through Ginkgo Biloba leaf extract. • The synthesized AgNPs is of high crystallinity, stable and good dispersion with smaller sizes between 10–16 nm. • The achieved AgNPs exhibits good antibacterial activities. • The biosynthesis method is advantageous for its cost effectiveness, availability, portability, nontoxic and environmentally benign.

  3. Synchrotron radiation photoelectron spectroscopy study of dextran-coated Fe3O4 magnetic nanoparticles

    International Nuclear Information System (INIS)

    Li Shaoxia; Meng Qiang; Wang Bing; Feng Weiyue; Wang Zhuo; Kui Rexi; Qian Haijie; Wang Jia'o

    2009-01-01

    Dextran-coated Fe 3 O 4 nanoparticles were prepared by untrasonification of Fe 3 O 4 nanoparticles with dextran at 85 degree C in sodium citrate medium. The surface chemical component, structure and bond of uncoated and dextran-coated nanoparticles were measured by synchrotron radiation XPS(X-ray photoelectron spectroscopy). Qualitative and quantitative analysis of C1s and O1s of Fe 3 O 4 and dextran-Fe 3 O 4 showed that the Fe 3 O 4 nanoparticles were successively coated by sodium citrate via Fe-O-C bond, and dextrans, which can be linked with their carboxylate moiety via hydrogen bond. Sodium citrate could enhance the disperse stability of reaction system and hydrophilicity of dextran-Fe 3 O 4 . (authors)

  4. Phytosynthesis and photocatalytic activity of magnetite (Fe{sub 3}O{sub 4}) nanoparticles using the Andean blackberry leaf

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Brajesh, E-mail: krmbraj@gmail.com [Centro de Nanociencia y Nanotecnologia, Universidad de las Fuerzas Armadas ESPE, Av. Gral. Rumiñahui s/n, Sangolqui, P.O. BOX 171-5-231B (Ecuador); Department of Chemistry, TATA College, Kolhan University, Chaibasa, 833202, Jharkhand (India); Smita, Kumari; Cumbal, Luis; Debut, Alexis [Centro de Nanociencia y Nanotecnologia, Universidad de las Fuerzas Armadas ESPE, Av. Gral. Rumiñahui s/n, Sangolqui, P.O. BOX 171-5-231B (Ecuador); Galeas, Salome; Guerrero, Victor H. [Laboratorio de Nuevos Materiales, Departamento de Materiales, Escuela Politécnica Nacional, Quito (Ecuador)

    2016-08-15

    In the present study, a simple, low cost, and ecofriendly synthesis of magnetite nanoparticles (Fe{sub 3}O{sub 4} NPs) has been developed using Andean blackberry leaf extract. UV–vis spectroscopy technique were used to study the initial formation of Fe{sub 3}O{sub 4} NPs. Morphology, crystallinity and surface properties of nanoparticles were studied using transmission electron microscopy (TEM), Dynamic light scattering (DLS), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and Thermal gravimetric (TG) techniques. TEM and DLS characterization indicated the formation of spherical Fe{sub 3}O{sub 4} NPs of average size 54.5 ± 24.6 nm. XRD and FTIR studies confirmed the existence of the cubic spinel phase of Fe{sub 3}O{sub 4} NPs and Fe−O peak at 570 cm{sup −1}, whereas TG analysis indicated that the nanoparticles contain 94% metal and 6% capping ligand. It has been observed that, as-synthesized Fe{sub 3}O{sub 4} NPs exhibited photocatalytic activity for degradation of organic dyes such as methylene blue (k = 0.0105475 min{sup −1}), congo red (k = 0.0043240 min{sup −1}), and methyl orange (k = 0.0028930 min{sup −1}), efficiently. The antioxidant activity of Fe{sub 3}O{sub 4} NPs against 1, 1-diphenyl-2-picrylhydrazyl were also evaluated. - Highlights: • We report extracellular phytosynthesis of Fe{sub 3}O{sub 4} nanoparticles using the Andean blackberry leaf. • The synthesized Fe{sub 3}O{sub 4} nanoparticles are spherical and average size is 54.5 ± 24.6 nm. • It showed enhanced photocatalytic activity and weak antioxidant efficacy. • Environmentally benign, non-toxic and cost-effective method is suggested.

  5. Magnetic properties of iron-oxide and (iron, cobalt)-oxide nanoparticles synthesized in polystyrene resin matrix

    International Nuclear Information System (INIS)

    Naik, R.; Kroll, E.; Rodak, D.; Tsoi, G.M.; McCullen, E.; Wenger, L.E.; Suryanarayanan, R.; Naik, V.M.; Vaishnava, P.P.; Tao, Qu; Boolchand, P.

    2004-01-01

    A sulfonated polystyrene resin matrix was ion exchanged with aqueous solutions of (1) FeCl 2 , (2) FeCl 3 , (3) 2FeCl 2 :FeCl 3 , (4) 9FeCl 2 :CoCl 2 , and (5) 4FeCl 2 :CoCl 2 to prepare magnetic nanoparticles of varying size. The samples were characterized by X-ray diffraction (XRD), 57 Fe Mossbauer spectroscopy, X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM), and identify two major phases: γ-Fe 2 O 3 , CoFe 2 O 4 , and perhaps a minor Fe 3 O 4 phase. SQUID magnetometry measurements indicate superparamagnetic particles with blocking temperatures (T B ) ranging from 20 K to room temperature

  6. Magnetic properties of iron-oxide and (iron, cobalt)-oxide nanoparticles synthesized in polystyrene resin matrix

    Energy Technology Data Exchange (ETDEWEB)

    Naik, R. E-mail: naik@physics.wayne.edu; Kroll, E.; Rodak, D.; Tsoi, G.M.; McCullen, E.; Wenger, L.E.; Suryanarayanan, R.; Naik, V.M.; Vaishnava, P.P.; Tao, Qu; Boolchand, P

    2004-05-01

    A sulfonated polystyrene resin matrix was ion exchanged with aqueous solutions of (1) FeCl{sub 2}, (2) FeCl{sub 3}, (3) 2FeCl{sub 2}:FeCl{sub 3}, (4) 9FeCl{sub 2}:CoCl{sub 2}, and (5) 4FeCl{sub 2}:CoCl{sub 2} to prepare magnetic nanoparticles of varying size. The samples were characterized by X-ray diffraction (XRD), {sup 57}Fe Mossbauer spectroscopy, X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM), and identify two major phases: {gamma}-Fe{sub 2}O{sub 3}, CoFe{sub 2}O{sub 4}, and perhaps a minor Fe{sub 3}O{sub 4} phase. SQUID magnetometry measurements indicate superparamagnetic particles with blocking temperatures (T{sub B}) ranging from 20 K to room temperature.

  7. Magnetic properties of iron-oxide and (iron, cobalt)-oxide nanoparticles synthesized in polystyrene resin matrix

    Science.gov (United States)

    Naik, R.; Kroll, E.; Rodak, D.; Tsoi, G. M.; McCullen, E.; Wenger, L. E.; Suryanarayanan, R.; Naik, V. M.; Vaishnava, P. P.; Tao, Qu; Boolchand, P.

    2004-05-01

    A sulfonated polystyrene resin matrix was ion exchanged with aqueous solutions of (1) FeCl2, (2) FeCl3, (3) 2FeCl2:FeCl3, (4) 9FeCl2:CoCl2, and (5) 4FeCl2:CoCl2 to prepare magnetic nanoparticles of varying size. The samples were characterized by X-ray diffraction (XRD), 57Fe Mossbauer spectroscopy, X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM), and identify two major phases: γ-Fe2O3, CoFe2O4, and perhaps a minor Fe3O4 phase. SQUID magnetometry measurements indicate superparamagnetic particles with blocking temperatures (TB) ranging from 20K to room temperature.

  8. Fe3O4@Au composite magnetic nanoparticles modified with cetuximab for targeted magneto-photothermal therapy of glioma cells.

    Science.gov (United States)

    Lu, Qianling; Dai, Xinyu; Zhang, Peng; Tan, Xiao; Zhong, Yuejiao; Yao, Cheng; Song, Mei; Song, Guili; Zhang, Zhenghai; Peng, Gang; Guo, Zhirui; Ge, Yaoqi; Zhang, Kangzhen; Li, Yuntao

    2018-01-01

    Thermoresponsive nanoparticles have become an attractive candidate for designing combined multimodal therapy strategies because of the onset of hyperthermia and their advantages in synergistic cancer treatment. In this paper, novel cetuximab (C225)-encapsulated core-shell Fe 3 O 4 @Au magnetic nanoparticles (Fe 3 O 4 @Au-C225 composite-targeted MNPs) were created and applied as a therapeutic nanocarrier to conduct targeted magneto-photothermal therapy against glioma cells. The core-shell Fe 3 O 4 @Au magnetic nanoparticles (MNPs) were prepared, and then C225 was further absorbed to synthesize Fe 3 O 4 @Au-C225 composite-targeted MNPs. Their morphology, mean particle size, zeta potential, optical property, magnetic property and thermal dynamic profiles were characterized. After that, the glioma-destructive effect of magnetic fluid hyperthermia (MFH) combined with near-infrared (NIR) hyperthermia mediated by Fe 3 O 4 @Au-C225 composite-targeted MNPs was evaluated through in vitro and in vivo experiments. The inhibitory and apoptotic rates of Fe 3 O 4 @Au-C225 composite-targeted MNPs-mediated combined hyperthermia (MFH+NIR) group were significantly higher than other groups in vitro and the marked upregulation of caspase-3, caspase-8, and caspase-9 expression indicated excellent antitumor effect by inducing intrinsic apoptosis. Furthermore, Fe 3 O 4 @Au-C225 composite-targeted MNPs-mediated combined hyperthermia (MFH+NIR) group exhibited significant tumor growth suppression compared with other groups in vivo. Our studies illustrated that Fe 3 O 4 @Au-C225 composite-targeted MNPs have great potential as a promising nanoplatform for human glioma therapy and could be of great value in medical use in the future.

  9. A sol-gel method to synthesize indium tin oxide nanoparticles

    Institute of Scientific and Technical Information of China (English)

    Xiuhua Li; Xiujuan xu; Xin Yin; Chunzhong Li; Jianrong Zhang

    2011-01-01

    Transparent conductive indium tin oxide (ITO) nanoparticles were synthesized by a novel sol-gel method.Granulated indium and tin were dissolved in HNO3 and partially complexed with citric acid.A sol-gel process was induced when tertiary butyl alcohol was added dropwise to the above solution.ITO nanoparticles with an average crystallite size of 18.5 nm and surface area of 32.6 m2/g were obtained after the gel was heat-treated at 700 C.The ITO nanoparticles showed good sinterability,the starting sintering temperature decreased sharply to 900 C,and the 1400 C sintered pellet had a density of 98.1 % of theoretical density (TD).

  10. Diazonium salt-mediated synthesis of new amino, hydroxy, propargyl, and maleinimido-containing superparamagnetic Fe@C nanoparticles as platforms for linking bio-entities or organocatalytic moieties

    Science.gov (United States)

    Bunge, Alexander; Magerusan, Lidia; Morjan, Ion; Turcu, Rodica; Borodi, Gheorghe; Liebscher, Jürgen

    2015-09-01

    New magnetic Fe@C nanoparticles in the size range of about 20-50 nm functionalized with amino, hydroxy, propargyl, or maleinimido groups were synthesized by reaction with aryl diazonium salts. Aryl diazonium salts wherein the functional groups are linked via a sulfonamide moiety turned out to be advantageous over those with direct linkage. The obtained Fe@C nanoparticles represent magnetic nanoplatforms for linking bio-entities and organocatalysts using amide formation, CuAAC, or thiol-ene click chemistry as exemplified by selected examples. The Fe@C nanoparticles obtained exhibit supramolecular behavior with high value of saturation magnetization rendering them attractive for practical applications in biomedicine and organocatalysis.

  11. Synthesizing Zno Nanoparticles by High-Energy Milling and Investigating Their Antimicrobial Effect

    Directory of Open Access Journals (Sweden)

    N Mohammadi

    2015-07-01

    Results: The study results demonstrated that size of the synthesized nanoparticles was within the range of 20 -90 nm and their morphology was reported as nanorod and nanoparticles with multifaceted cross-section. An increase in the density of nanoparticles resulted in a rise in the antimicrobial effect. Moreover, Staphylococcus aureus bacteria inhibition zone was 3±0.5 and 7±0.5 mm respectively at the density of 6 and 10 mM. The MIC and MBC of ZnO nanoparticles provided for Staphylococcus aureus were observed 3±3 and 2.5±0 mg/ml, whereas they were reported 7.5±0 and 8±0 mg/ml for Escherichia coli bacteria. Conclusion: The findings of the present study revealed that ZnO nanomaterials could be synthesized by applying high-energy milling on micron-scaled ZnO particles. In addition, they can be utilized in food packaging and preservation process.

  12. Surface functionalization of microwave plasma-synthesized silica nanoparticles for enhancing the stability of dispersions

    Science.gov (United States)

    Sehlleier, Yee Hwa; Abdali, Ali; Schnurre, Sophie Marie; Wiggers, Hartmut; Schulz, Christof

    2014-08-01

    Gas phase-synthesized silica nanoparticles were functionalized with three different silane coupling agents (SCAs) including amine, amine/phosphonate and octyltriethoxy functional groups and the stability of dispersions in polar and non-polar dispersing media such as water, ethanol, methanol, chloroform, benzene, and toluene was studied. Fourier transform infrared spectroscopy showed that all three SCAs are chemically attached to the surface of silica nanoparticles. Amine-functionalized particles using steric dispersion stabilization alone showed limited stability. Thus, an additional SCA with sufficiently long hydrocarbon chains and strong positively charged phosphonate groups was introduced in order to achieve electrosteric stabilization. Steric stabilization was successful with hydrophobic octyltriethoxy-functionalized silica nanoparticles in non-polar solvents. The results from dynamic light scattering measurements showed that in dispersions of amine/phosphonate- and octyltriethoxy-functionalized silica particles are dispersed on a primary particle level. Stable dispersions were successfully prepared from initially agglomerated nanoparticles synthesized in a microwave plasma reactor by designing the surface functionalization.

  13. Luminescent and photocatalytic properties of cadmium sulfide nanoparticles synthesized via microwave irradiation

    International Nuclear Information System (INIS)

    Yang Huaming; Huang Chenghuan; Li Xianwei; Shi Rongrong; Zhang Ke

    2005-01-01

    Uniform cadmium sulfide (CdS) nanoparticles of about 6 nm in crystal size have been successfully synthesized via microwave irradiation. The as-prepared sample has a uniform morphology and high purity. The red photoluminescence spectrum of the CdS nanoparticles displays a strong peak at 602 nm by using a 300 nm excitation wavelength. The photocatalytic oxidation of methyl orange (MeO) in CdS suspensions under ultraviolet illumination was investigated. The results indicate that a low pH value (pH 2.0) and low reaction temperatures (20-30 deg. C) will facilitate the decolorization of the MeO solution. The photodegradation degree decreases with increasing the pH value and temperature of solution. The efficiency of the recycled CdS semiconductor becomes lower due to the deposit of elemental Cd on the CdS surface, which weakens the photocatalytic activity. The luminescent and photocatalytic mechanisms of the as-prepared CdS nanoparticles were primarily discussed. Microwave irradiation is proved to be a convenient, efficient and environmental-friendly one-step route to synthesize nanoparticles

  14. Size-tunable silver nanoparticles synthesized by using aminopolycarboxylic acids at ambient-temperature

    International Nuclear Information System (INIS)

    Malkar, Vishwabharati V.; Chadha, R.; Biswas, N.; Mukherjee, T.; Kapoor, S.

    2009-01-01

    Full text: Stable aqueous sols of silver nanoparticles are prepared by using various aminopolycarboxylic acids as stabilizing agents at ambient temperature. The precursor silver perchlorate is reduced using γ radiations. Interestingly, it was observed that size of silver nanoparticles obtained could be tuned using various aminopolycarboxylic acids of varying carboxylic acid groups The silver sols synthesized by this method were stable for months and particles obtained were monodisperse in almost all cases. Particle formation was observed at equimolar concentration of silver and aminopolycarboxylic acids. The stabilization of particles even in the absence of any polymer indicates that the adsorption of aminopolycarboxylic acids on silver particle is a spontaneous process. The adsorbed aminopolycarboxylic acids can saturate the residual valence force of the silver atom on the particle surface by coordinating with unoccupied orbital. Adsorption of aminopolycarboxylic acids does not lead to any change in surface plasmon band of silver nanoparticles; this indicates that anions in the double layer on the colloidal particle have different chemical properties from the free anions. Synthesized silver nanoparticles were characterized by UV-visible spectrophotometer, X-ray Diffraction, Dynamic Light Scattering and Transmission Electron Microscope

  15. Green synthesis and antimicrobial activity of monodisperse silver nanoparticles synthesized using Ginkgo Biloba leaf extract

    Science.gov (United States)

    Ren, Yan-yu; Yang, Hui; Wang, Tao; Wang, Chuang

    2016-11-01

    Various parts of plants can be used as a raw material for the synthesis of nanoparticles, which is eco-friendly way and does not involve any harmful chemicals. In this project, Ginkgo biloba leaf, an abundantly available medicinal plant in China, was for the first time adopted as a reducing and stabilizing agent to synthesize smaller sized and stable silver nanoparticles (AgNPs). To improve the quality of AgNPs, the reduction was accelerated by changing the concentrations of initial Ag+ (0.02, 0.04, 0.06 and 0.08 mol/L) of the reaction mixture consisting of silver nitrate solution (AgNO3) and Ginkgo biloba leaf extract. At pH = 8 and lower AgNO3 concentration (0.02 mol/L), a colloid consisting of well-dispersed spherical nanoparticles was obtained. The synthesized nanocrystals were successfully characterized by UV-vis and XRD. TEM images revealed the size of the spherical AgNPs ranged between 10-16 nm. FTIR analysis revealed that biological macromolecules with groups of sbnd NH2, sbnd OH, and others were distributed on the surface of the nanoparticles. The biosynthesized AgNPs exhibited good antibacterial activities against gram-negative bacteria and gram-positive bacteria. Compared to traditional chemical methods, Ginkgo biloba leaf extract provides an easy green synthetical way. It is anticipated that the biosynthesized AgNPs can be used in areas such as cosmetics, foods and medical applications.

  16. Biocompatibility of Fe3O4@Au composite magnetic nanoparticles in vitro and in vivo

    Directory of Open Access Journals (Sweden)

    Li Y

    2011-11-01

    Full Text Available Yuntao Li1,2, Jing Liu1, Yuejiao Zhong3, Jia Zhang1, Ziyu Wang1, Li Wang1, Yanli An1, Mei Lin1, Zhiqiang Gao2, Dongsheng Zhang11School of Medicine, Southeast University, Nanjing, Jiangsu Province, People's Republic of China; 2Second Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu Province, People's Republic of China; 3Jiangsu Cancer Hospital and Jiangsu Institute of Cancer Research, Nanjing, Jiangsu Province, People's Republic of ChinaPurpose: This research was conducted to assess the biocompatibility of the core-shell Fe3O4@Au composite magnetic nanoparticles (MNPs, which have potential application in tumor hyperthermia. Methods: Fe3O4@Au composite MNPs with core-shell structure were synthesized by reduction of Au3+ in the presence of Fe3O4-MNPs prepared by improved co-precipitation. Cytotoxicity assay, hemolysis test, micronucleus (MN assay, and detection of acute toxicity in mice and beagle dogs were then carried out.Results: The result of cytotoxicity assay showed that the toxicity grade of this material on mouse fibroblast cell line (L-929 was classified as grade 1, which belongs to no cytotoxicity. Hemolysis rates showed 0.278%, 0.232%, and 0.197%, far less than 5%, after treatment with different concentrations of Fe3O4@Au composite MNPs. In the MN assay, there was no significant difference in MN formation rates between the experimental groups and negative control (P > 0.05, but there was a significant difference between the experimental groups and the positive control (P < 0.05. The median lethal dose of the Fe3O4@Au composite MNPs after intraperitoneal administration in mice was 8.39 g/kg, and the 95% confidence interval was 6.58-10.72 g/kg, suggesting that these nanoparticles have a wide safety margin. Acute toxicity testing in beagle dogs also showed no significant difference in body weight between the treatment groups at 1, 2, 3, and 4 weeks after liver injection and no behavioral changes. Furthermore, blood

  17. Use of Fe3O4 Nanoparticles for Enhancement of Biosensor Response to the Herbicide 2,4-Dichlorophenoxyacetic Acid

    Science.gov (United States)

    Loh, Kee-Shyuan; Lee, Yook Heng; Musa, Ahmad; Salmah, Abdul Aziz; Zamri, Ishak

    2008-01-01

    Magnetic nanoparticles of Fe3O4 were synthesized and characterized using transmission electron microscopy and X-ray diffraction. The Fe3O4 nanoparticles were found to have an average diameter of 5.48 ±1.37 nm. An electrochemical biosensor based on immobilized alkaline phosphatase (ALP) and Fe3O4 nanoparticles was studied. The amperometric biosensor was based on the reaction of ALP with the substrate ascorbic acid 2-phosphate (AA2P). The incorporation of the Fe3O4 nanoparticles together with ALP into a sol gel/chitosan biosensor membrane has led to the enhancement of the biosensor response, with an improved linear response range to the substrate AA2P (5-120 μM) and increased sensitivity. Using the inhibition property of the ALP, the biosensor was applied to the determination of the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D). The use of Fe3O4 nanoparticles gives a two-fold improvement in the sensitivity towards 2,4-D, with a linear response range of 0.5-30 μgL-1. Exposure of the biosensor to other toxicants such as heavy metals demonstrated only slight interference from metals such as Hg2+, Cu2+, Ag2+ and Pb2+. The biosensor was shown to be useful for the determination of the herbicide 2, 4-D because good recovery of 95-100 percent was obtained, even though the analysis was performed in water samples with a complex matrix. Furthermore, the results from the analysis of 2,4-D in water samples using the biosensor correlated well with a HPLC method. PMID:27873839

  18. Use of Fe3O4 Nanoparticles for Enhancement of Biosensor Response to the Herbicide 2,4-Dichlorophenoxyacetic Acid

    Directory of Open Access Journals (Sweden)

    Ishak Zamri

    2008-09-01

    Full Text Available Magnetic nanoparticles of Fe3O4 were synthesized and characterized using transmission electron microscopy and X-ray diffraction. The Fe3O4 nanoparticles were found to have an average diameter of 5.48 ±1.37 nm. An electrochemical biosensor based on immobilized alkaline phosphatase (ALP and Fe3O4 nanoparticles was studied. The amperometric biosensor was based on the reaction of ALP with the substrate ascorbic acid 2-phosphate (AA2P. The incorporation of the Fe3O4 nanoparticles together with ALP into a sol gel/chitosan biosensor membrane has led to the enhancement of the biosensor response, with an improved linear response range to the substrate AA2P (5-120 μM and increased sensitivity. Using the inhibition property of the ALP, the biosensor was applied to the determination of the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D. The use of Fe3O4 nanoparticles gives a two-fold improvement in the sensitivity towards 2,4-D, with a linear response range of 0.5-30 μgL-1. Exposure of the biosensor to other toxicants such as heavy metals demonstrated only slight interference from metals such as Hg2+, Cu2+, Ag2+ and Pb2+. The biosensor was shown to be useful for the determination of the herbicide 2, 4-D because good recovery of 95-100 percent was obtained, even though the analysis was performed in water samples with a complex matrix. Furthermore, the results from the analysis of 2,4-D in water samples using the biosensor correlated well with a HPLC method.

  19. PREPARATION,COMPLEX MECHANISM AND STRUCTURE MODEL OF METALLOPHTHALOC- YANINE-Fe3O4 NANOPARTICLES COMPOSITE

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    MPc-Fe3O4-nanoparticles composite(M=Co, Cu, Ni, Mn) have been prepared and the factors that influence their mean size have been studied. The mean size of the nanoparticles composite increase with the increase of complex temperature. The interaction of MPc with Fe3O4 nanoparticles has been studied. There are M-O covalent bonding and ionic bonding between MPc and Fe3O4 nanoparticles. The intensities of M-O bonding and ionic bonding are in vestigated .The complex mechanism of MPc with Fe3O4 nanoparticles have been studied. First, there are complex between MPc and all Fe3O4 nanoparticles. Then, Fe3O4 nanoparticles accumulate together to form the accumulators, MPc have the function of cohering Fe3O4 nanoparticles. A considerable number of MPc combine with Fe3O4 nanoparticles on the surface of the accumulators to form MPc-Fe3O4 nanoparticles composite. All the above proesses take place spontaneously. The structure model of MPc-Fe3O4 nanoparticles composite has also been investigated. Inside the MPc-Fe3O4 nanoparticles composite, Fe3O4 nanoparticles accumulate together without order, on the surface of the composite, MPc form molecular dispersion layer. The threshold of molecular dispersion layer are also investigated.

  20. Effect of surfactant amount on the morphology and magnetic properties of monodisperse ZnFe{sub 2}O{sub 4} nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Haitao, E-mail: zht95711lunwen@163.com; Liu, Ruiping; Zhang, Qiang; Wang, Qiao

    2016-03-15

    Graphical abstract: Polyol process to monodisperse ZnFe{sub 2}O{sub 4} nanoparticles. - Highlights: • An one-step, facile and inexpensive synthetic route to monodisperse ZnFe{sub 2}O{sub 4} nanoparticles is described. • The sodium citrate stabilized ZnFe{sub 2}O{sub 4} nanoparticles with a diameter in the 5–8 nm size range can be easily dispersed in water. • The synthesis is very robust in terms of variations of experimental parameters. • ZnFe{sub 2}O{sub 4} nanoparticles present ferrimagnetic behavior at room temperature with a small hysteresis. - Abstract: The spinel ZnFe{sub 2}O{sub 4} ferrites with sodium citrate as a surfactant were fabricated by polyol process. The effect of surfactant amount on the structure, morphology and magnetic properties of ZnFe{sub 2}O{sub 4} ferrites were investigated by X-ray diffraction(XRD), transmission electron microscope (TEM), thermogravimetric and differential scanning calorimetry (TG–DSC) and vibrating sample magnetometry (VSM), respectively. The results indicate that the structure of ZnFe{sub 2}O{sub 4} ferrites is a pure cubic spinel structure with a particle size of 5–8 nm. The dispersion of the synthesized ZnFe{sub 2}O{sub 4} is enhanced when the mole ratio of Fe(acac){sub 3} to sodium citrate decreases. The synthesized particles present ferrimagnetic behavior with a small hysteresis at room temperature. The increase of surfactant amount conversely leads to the decrease in the saturation magnetization value (Ms) especially when the mole ratio of Fe(acac){sub 3} to sodium citrate decreases to 8:3. Its Ms value is drastically reduced to 18.97 emu/g.

  1. Asymmetric dumbbell-shaped silver nanoparticles and spherical gold nanoparticles green-synthesized by mangosteen (Garcinia mangostana pericarp waste extracts

    Directory of Open Access Journals (Sweden)

    Park JS

    2017-09-01

    Full Text Available Ji Su Park, Eun-Young Ahn, Youmie Park College of Pharmacy, Inje Institute of Pharmaceutical Sciences and Research, Inje University, Gimhae, Gyeongnam, Republic of Korea Abstract: Mangosteen (Garcinia mangostana pericarp waste extract was used to synthesize gold and silver nanoparticles by a green strategy. The extract was both a reducing and stabilizing agent during synthesis. Phytochemical screening of the extract was conducted to obtain information regarding the presence/absence of primary and secondary metabolites in the extract. The in vitro antioxidant activity results demonstrated that the extract had excellent antioxidant activity, which was comparable to a standard (butylated hydroxy toluene. Spherical gold nanoparticles (gold nanoparticles green synthesized by mangosteen pericarp extract [GM-AuNPs] with an average size of 15.37±3.99 to 44.20±16.99 nm were observed in high-resolution transmission electron microscopy (HR-TEM images. Most interestingly, the silver nanoparticles (silver nanoparticles green synthesized by mangosteen pericarp extract [GM-AgNPs] had asymmetric nanodumbbell shapes where one tail grew from a spherical head. The average head size was measured to be 13.65±5.07 to 31.08±3.99 nm from HR-TEM images. The hydrodynamic size of both nanoparticles tended to increase with increasing extract concentration. Large negative zeta potentials (–18.92 to –34.77 mV suggested that each nanoparticle solution possessed excellent colloidal stability. The reaction yields were 99.7% for GM-AuNPs and 82.8% for GM-AgNPs, which were assessed by inductively coupled plasma optical emission spectroscopy. A high-resolution X-ray diffraction pattern confirmed the face-centered cubic structure of both nanoparticles. Based on phytochemical screening and Fourier transform infrared spectra, the hydroxyl functional groups of carbohydrates, flavonoids, glycosides, and phenolic compounds were most likely involved in a reduction reaction of

  2. Assembly of Fe3O4 nanoparticles on SiO2 monodisperse spheres

    Indian Academy of Sciences (India)

    Assembly of Fe3O4 nanoparticles on SiO2 monodisperse spheres. K C BARICK and D BAHADUR*. Department of Metallurgical Engineering and Materials Science, Indian Institute of Technology Bombay,. Mumbai 400 076, India. Abstract. The assembly of superparamagnetic Fe3O4 nanoparticles on submicroscopic SiO2 ...

  3. Electrodeposition of Fe{sub 2}O{sub 3} nanoparticles and its supercapacitive properties

    Energy Technology Data Exchange (ETDEWEB)

    Kadam, S. L., E-mail: snehal.kadam54@gmail.com; Padwal, P. M., E-mail: pal-soni279@yahoo.com; Mane, S. M., E-mail: manesagar99@gmail.com; Kulkarni, S. B., E-mail: sbk-physics@yahoo.com [Department of Physics, The Institute of Science, Madam Cama Road, Mumbai-400032 (India)

    2016-04-13

    Fe{sub 2}O{sub 3} metal oxide nanoparticles are synthesized by electrodeposition method on stainless steel substrate. The crystal structure and surface morphological studies of the obtained metal oxide thin film are carried out by using X-ray diffraction (XRD) technique and Scanning Electron Microscopy (SEM) respectively. The electrochemical properties of Fe{sub 2}O{sub 3} thin film like Cyclic Voltammetry (CV), Galvonostatic Charge-Discharge (GCD) and Electrochemical Impedance Spectroscopy (EIS) are studied in a bath of 0.5 M Na{sub 2}SO{sub 4} as electrolyte. The observed specific capacitance shows improved values 135 Fg{sup −1} at 5 mVs{sup −1} scan rate. The electrochemical stability of Fe{sub 2}O{sub 3} electrode is investigated using cyclic voltammetry for 1000 cycles at a scan rate 50 mVs{sup −1}. The Fe{sub 2}O{sub 3} electrode exhibits superior cycling stability with only 4-5% capacitance loss after one thousand cycles. The values of specific power and specific energy of Fe{sub 2}O{sub 3} electrode obtained from Galvonostatic charge discharge studies are 2250 W.kg{sup −1} and 63.15 Wh.kg{sup −1} respectively at current density 1 A/g. From all the electrochemical properties of Fe{sub 2}O{sub 3} electrode, it indicates that it will be promising electrode material for supercapacitor application.

  4. Characteristics of ceramic oxide nanoparticles synthesized using radio frequency produced thermal plasma

    International Nuclear Information System (INIS)

    Dhamale, Gayatri D.; Mathe, V.L.; Bhoraskar, S.V.; Ghorui, S.

    2015-01-01

    Thermal plasma devices with their unique processing capabilities due to extremely high temperature and steep temperature gradient play an important role in synthesis of ultrafine powders in the range of 100nm or less. High temperature gas phase synthesis in Radio Frequency (RF) thermal plasma reactor is an attractive route for mass production of refractory nanoparticles, especially in the case of rare earth oxides. Here we report synthesis of Yttrium Oxide (Y_2O_3), Neodymium Oxide (Nd_2O_3) and Aluminum Oxide (Al_2O_3) in an inductively coupled radio frequency thermal plasma reactor. Synthesized nanoparticles find wide application in various fields like gate dielectrics, photocatalytic applications, laser devices and photonics. Nano sized Yttrium oxide, Neodymium Oxide and Aluminum oxide powders were separately synthesized in an RF plasma reactor starting with micron sized irregular shaped precursor powders. The system was operated at 3MHz in atmospheric pressure at different power levels. Synthesized powders were scrapped out from different deposition locations inside the reactor and characterized for their phase, morphology, particle size, crystallinity and other characteristic features. Highly crystalline nature of the synthesized particles, narrow size distribution, location dependent phase formation, and distinct variation in the inherent defect states compared to the bulk are some of the important characteristic features observed

  5. New approach towards the polyol route to fabricate MFe2O4 magnetic nanoparticles: The use of MCl2 and Fe(acac)3 as chemical precursors

    Science.gov (United States)

    Solano, Eduardo; Yáñez, Ramón; Ricart, Susagna; Ros, Josep

    2015-05-01

    A new more efficient approach of the polyol route to generate MFe2O4 (M=Mn, Fe, Co, Ni, Cu, Zn) nanoparticles in triethylene glycol (TREG) is presented. The selected thermal procedure is based on the Fe metalorganic precursor (iron(III) acetylacetonate) decomposition in presence of an inorganic transition metal chloride salt (MCl2, M=Mn, Fe, Co, Ni, Cu, Zn) to produce high quality polar dispersible nanoparticles with lower production cost. In addition, the nanoparticles are stabilized by ionic (from the Cl-) and steric (TREG as capping ligand) effects inducing into the nanoparticles an extraordinary stability in different polar solvents. As result of this optimized methodology, the colloidal polar dispersible nanoparticles present a size around 10 nm with an adequate size dispersion demonstrated by analyzing transmission electron microscopy (TEM) images. X-ray powder diffraction (XRPD) results corroborate the absence of secondary phases and the high crystalline degree obtained for the spinel structure, fact proved by using synchrotron X-ray diffraction. The high magnetic performance at low and room temperature of the nanoparticles studied by magnetometry proves the high internal crystal order of the spinel. Parallel to this, the influence of the heating ramp and annealing time in the thermal procedure were also investigated for the CuFe2O4 case, where a relationship between these two parameters and the final size and their associated diameter distribution was found, allowing a possible size control of the final ferrite magnetic nanoparticles synthesized.

  6. Enhanced antibacterial activity of zinc oxide nanoparticles synthesized using Petroselinum crispum extracts

    Energy Technology Data Exchange (ETDEWEB)

    Stan, Manuela, E-mail: manuela.stan@itim-cj.ro; Popa, Adriana; Toloman, Dana; Silipas, Teofil-Danut [National Institute for Research and Development of Isotopic and Molecular Technologies, 67-103 Donat, 400293 Cluj-Napoca (Romania); Vodnar, Dan Cristian [University of Agricultural Sciences and Veterinary Medicine, Department of Food Science and Technology, 3-5 Manastur Street, 400372 Cluj-Napoca (Romania); Katona, Gabriel [Babes-Bolyai University, Faculty of Chemistry and Chemical Engineering, 11 Arany Janos Street, 400028 Cluj-Napoca (Romania)

    2015-12-23

    The present contribution reports the synthesis of zinc oxide nanoparticles (ZnO NPs) using aqueous leaf and root extracts of Petroselinum crispum (parsley) and characterization of as-prepared samples. ZnO NPs are subjected to X-ray diffraction (XRD), transmission electron microscopy (TEM) and electron paramagnetic resonance (EPR) studies. The XRD studies reveal a hexagonal wurtzite structure without supplementary diffraction lines for all ZnO samples. TEM analysis shows that the particle size is influenced by the type of plant extract. The EPR spectra indicate the presence of Mn{sup 2+} ions in ZnO sample synthesized using P. crispum leaf extract, while zinc vacancy complexes and oxygen vacancies are evidenced in all analyzed samples. ZnO NPs synthesized using P. crispum extracts exhibit increased (2-16 times) antibacterial activity as compared to chemically synthesized ZnO NPs.

  7. Enhanced antibacterial activity of zinc oxide nanoparticles synthesized using Petroselinum crispum extracts

    International Nuclear Information System (INIS)

    Stan, Manuela; Popa, Adriana; Toloman, Dana; Silipas, Teofil-Danut; Vodnar, Dan Cristian; Katona, Gabriel

    2015-01-01

    The present contribution reports the synthesis of zinc oxide nanoparticles (ZnO NPs) using aqueous leaf and root extracts of Petroselinum crispum (parsley) and characterization of as-prepared samples. ZnO NPs are subjected to X-ray diffraction (XRD), transmission electron microscopy (TEM) and electron paramagnetic resonance (EPR) studies. The XRD studies reveal a hexagonal wurtzite structure without supplementary diffraction lines for all ZnO samples. TEM analysis shows that the particle size is influenced by the type of plant extract. The EPR spectra indicate the presence of Mn 2+ ions in ZnO sample synthesized using P. crispum leaf extract, while zinc vacancy complexes and oxygen vacancies are evidenced in all analyzed samples. ZnO NPs synthesized using P. crispum extracts exhibit increased (2-16 times) antibacterial activity as compared to chemically synthesized ZnO NPs

  8. High temperature stability of surfactant capped CoFe2O4 nanoparticles

    International Nuclear Information System (INIS)

    Ayyappan, S.; Panneerselvam, G.; Antony, M.P.; Philip, John

    2011-01-01

    Highlights: → Self-assembled molecular layers of surfactant on nanoparticles are often used to modify surface properties. → We demonstrate that a surfactant nanolayer on CoFe 2 O 4 nanoparticles can act as a strong reducing agent under high temperature vacuum annealing. → We propose a possible reduction mechanism of CoFe 2 O 4 nanoparticles under air and vacuum annealing. → Our results are important in the understanding of the stability of nanoparticles at high temperatures. - Abstract: We investigate the effect of adsorbed surfactant on the structural stability of CoFe 2 O 4 nanoparticles during vacuum thermal annealing. In-situ high temperature X-ray diffraction studies show a reduction of oleic acid coated CoFe 2 O 4 nanoparticles into α-Fe and CoO under annealing at 800 deg. C. On the contrary, the uncoated CoFe 2 O 4 nanoparticles remains stable, with its cubic phase intact, even at 1000 deg. C. Thermo-gravimetric analysis coupled mass spectra reveals that the evolved carbon from the surfactant aids the removal of oxygen atom from CoFe 2 O 4 lattice thereby reducing it to α-Fe and CoO phases. These results are important in tailoring stable CoFe 2 O 4 nanostructures for various applications.

  9. Polyethyleneimine-modified superparamagnetic Fe3O4 nanoparticles for lipase immobilization: Characterization and application

    International Nuclear Information System (INIS)

    Khoobi, Mehdi; Motevalizadeh, Seyed Farshad; Asadgol, Zahra; Forootanfar, Hamid; Shafiee, Abbas; Faramarzi, Mohammad Ali

    2015-01-01

    Magnetically separable nanospheres consisting of polyethyleneimine (PEI) and succinated PEI grafted on silica coated magnetite (Fe 3 O 4 ) were prepared and characterized using Fourier transform infrared spectroscopy, thermogravimetric analysis, X-ray diffraction, vibrating sample magnetometer, scanning electron microscopy and transmission electron microscopy. The prepared magnetic nanoparticles were then applied for physical adsorption or covalent attachment of Thermomyces lanuginosa lipase (TLL) via glutaraldehyde or hexamethylene diisocyanate. The reusability, storage, pH and thermal stabilities of the immobilized enzymes compared to that of free lipase were examined. The obtained results showed that the immobilized lipase on MNPs@PEI-GLU was the best biocatalyst which retained 80% of its initial activity after 12 cycles of application. The immobilized lipase on the selected support (MNPs@PEI-GLU) was also applied for the synthesis of ethyl valerate. Following 24 h incubation of the immobilized lipase on the selected support in n-hexane and solvent free media, the esterification percentages were 72.9% and 28.9%, respectively. - Graphical abstract: A schematic of the preparation of PEI- and succinated PEI-grafted Fe 3 O 4 MNPs (MNPs@PEI) and the immobilization of lipase by covalent bonding and adsorption. - Highlights: • Functionalized polyethylenimine-grafted magnetic nanoparticles were synthesized. • The prepared supports were fully characterized by various analysis methods. • Lipase was immobilized on the nanostructures by adsorption and covalent attachment. • Immobilized lipase produced ethyl valerate in solvent free medium

  10. Direct synthesis of L1 type Fe-Pt nanoparticles using microwave-polyol method

    International Nuclear Information System (INIS)

    Minami, Rumiko; Kitamoto, Yoshitaka; Chikata, Tsukasa; Kato, Shunsaku

    2005-01-01

    We report the synthesis of Fe-Pt nanoparticles with microwave irradiation during polyol-reduction reaction. Chemically ordered Fe-Pt nanoparticles with L1 structure are fabricated at 250 deg. C using a microwave-polyol method without any post-synthesis treatments. Moessbauer analyses reveal the nanoparticles have partially ordered L1 structure. The partially ordered Fe-Pt nanoparticles exhibit coercivity of 3.4 kOe, saturation magnetization of 49 emu/g, and anisotropy field of 83 kOe at room temperature

  11. Effective decolorization and adsorption of contaminant from industrial dye effluents using spherical surfaced magnetic (Fe_3O_4) nanoparticles

    International Nuclear Information System (INIS)

    Suriyaprabha, R.; Khan, Samreen Heena; Pathak, Bhawana; Fulekar, M. H.

    2016-01-01

    Treatment of highly concentrated Industrial dye stuff effluents released in the environment is the major issue faced in the era of waste management as well as in water pollution. Though there is availability of conventional techniques in large numbers, there is a need of efficient and effective advance technologies. In account of that, Nanotechnology plays a prominent role to treat the heavy metals, organic and inorganic contaminants using smart materials in nano regime (1 -100 nm). Among these nanomaterials like Iron Oxide (Fe_3O_4, magnetic nanoparticle) is one of the most promising candidates to remove the heavy metals from the industrial effluent. Fe_3O_4 is the widely used smart material with magnetic property having high surface area; high surface to volume ratio provides more surface for the chemical reaction for the surface adsorption. Fe_3O_4 nanoparticles have been synthesized using sonochemical method using ultra frequency in aqueous solution under optimized conditions. The as-synthesized nanoparticle was analyzed using different characterization tool. The Transmission Electron microscope (TEM) images revealed 10-12 nm spherical shape nanoparticles; crystal phase and surface morphology was confirmed by X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM), respectively. The functional group were identified by Fourier Transform-Infra Red Spectroscopy (FT-IR), revealed the bending and stretching vibrations associated with Iron Oxide nanoparticle. In present study, for the efficient removal of contaminants, different concentration (10-50 ppm) of dye stuff effluent has been prepared and subjected to adsorption and decolourization at definite time intervals with Fe_3O_4 nanoparticles. The concentration of Iron oxide and the time (45 mins) was kept fixed for the reaction whereas the concentration of dye stuff effluent was kept varying. It was found that the spherical shaped Fe_3O_4 proved to be the potential material for the adsorption of

  12. Antibacterial Activity of Silver Nanoparticles Synthesized by Using Extracts of Hedera helix

    Directory of Open Access Journals (Sweden)

    Ahmadreza Abbasifar

    2017-01-01

    Full Text Available Background Silver nanoparticles (AgNPs are one of the most widely applicable particles whose application is increasing in Nano world daily. Silver nanoparticles have expressed significant advances owing to wide range of applications in the field of bio-medical, sensors, antimicrobials, catalysts, electronics, optical fibers, agricultural, bio-labeling and the other areas. Green synthesis is the safe and easiest method of producing silver nanoparticles. Because of the production of the silver ions, silver nanoparticles are found to have the antibacterial activity. Objectives The aim of this study was to investigate antibacterial activity of silver nanoparticles synthesized by using extracts of Hedera helix against Bacillus subtilis and Klebsiella pneumoniae. Methods In this experimental study AgNPs were prepared by the reaction of 1mM silver nitrate and extracts of Hedera helix. Antibacterial activity of AgNPs was assessed by using disc diffusion method against Bacillus subtilis and Klebsiella pneumoniae. The AgNPs were characterized by UV-visible (vis spectrophotometer, particle size analyzer by dynamic light scattering (DLS method, transmission electron microscopy (TEM. Results AgNPs obtained showed significantly higher antimicrobial activities against B. subtilis and K. pneumonia in comparison to both AgNO3 and raw plant extracts. Conclusions Biological methods are a good competent for the chemical procedures, which are environment friendly and convenient.

  13. Photochemically synthesized heparin-based silver nanoparticles: an antimicrobial activity study

    Science.gov (United States)

    Rodriguez-Torres, Maria del Pilar; Acosta-Torres, Laura Susana; Díaz-Torres, Luis Armando

    2017-08-01

    The antimicrobial activity of silver nanoparticles has been extensively studied in the last years. Such nanoparticles constitute a potential and promising approach for the development of new antimicrobial systems especially due to the fact that several microorganisms are developing resistance to some already existing antimicrobial agents, therefore making antibacterial and antimicrobial studies on alternative materials necessary to overcome this issue. Silver nanoparticle concentration and size are determining factors on the antimicrobial activity of these nano systems. Heparin is a polysaccharide that belongs to the glycosaminoglycans (GAGs) family, molecules formed by a base disaccharide whose components are joined by a glycosidic linkage that is a repeating unit along their structure. It is highly sulfated making it a negatively charged material that is also widely used as an anticoagulant in Medicine because its biocompatibility besides it is also produced within the human body, specifically in the mast cells. Heparin alone possesses antimicrobial activity although it has not been studied very much in detail, it only has been demonstrated that it inhibits E. coli, P. aeruginosa, S. aureus and S. epidermidis, so taking this into account, this study is dedicated to assess UV photochemically-synthesized (λ=254 nm) heparin-based silver nanoparticles antimicrobial activity using the agar disk diffusion method complemented by the broth microdilution method to estimate de minimum inhibitory concentration (MIC), that is the lowest concentration at which an antimicrobial will inhibit visible growth of a microorganism. The strains used were the ones aforementioned to assess the antimicrobial activity degree these heparinbased nanoparticles exhibit.

  14. Optical and structure characterization of cinnamon nanoparticles synthesized by pulse laser ablation in liquid (PLAL)

    Science.gov (United States)

    Aqeel Salim, Ali; Bidin, Noriah; Bakhtiar, Hazri; Krishna Ghoshal, Sib; Azawi, Mohammed Al; Krishnan, Ganesan

    2018-05-01

    Organic nanoparticles development is under exploration due to its beneficial applications in nanobiomedical and research interests. PLAL technique of Q-switched 1064-Nd: YAG (10 ns pulse duration, repetition rate 1 Hz and laser energy 20-100 mJ) has inherent advantages and rapid growth of nanoparticles when compared to conventional methods because of the controlled fabricated nanoparticles, stability, and purity. Cinnamon sticks as a target are immersed in 5 ml ethanol medium and irradiated by a laser beam for the growth process. The morphology, optical characteristic, and bonding structure of cinnamon nanoparticles (CNPs) are determined and evaluated by transmission electron microscope (TEM), UV-Visible spectroscopy and Fourier transform infrared spectroscopy (FTIR). Spherical, homogenous and high crystallinity CNPs was revealed within the particle size range of 2 - 28 nm. The absorption band was found in the ultraviolent region around 259 nm and 319 nm. The present of FTIR spectra confirmed that the nanoparticles were covered by plant secondary metabolites. The experimental findings revealed that the synthesize CNPs in ethanol has a potential for nanomedicine applications.

  15. Green fabrication of agar-conjugated Fe{sub 3}O{sub 4} magnetic nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Hsieh, S; Huang, B Y; Lin, P Y; Chang, C W [Department of Chemistry and Center for Nanoscience and Nanotechnology, National Sun Yat-sen University, Kaohsiung 80424, Taiwan (China); Hsieh, S L [Department of Seafood Science, National Kaohsiung Marine University, Kaohsiung 81157, Taiwan (China); Wu, C C [Department of Nutrition and Health Sciences, Chang Jung Christian University, Tainan 71101, Taiwan (China); Wu, C H [Department of Computer Science and Information Engineering, National University of Kaohsiung, Kaohsiung 80811, Taiwan (China); Huang, Y S, E-mail: shsieh@facmail.NSYSU.edu.tw [Department of Food Science and Technology, Tajen University, Pingtung 90741, Taiwan (China)

    2010-11-05

    Magnetic nanoparticles are of great interest both for fundamental research and emerging applications. In the biomedical field, magnetite (Fe{sub 3}O{sub 4}) has shown promise as a hyperthermia-based tumor therapeutic. However, preparing suitable solubilized magnetite nanoparticles is challenging, primarily due to aggregation and poor biocompatibility. Thus methods for coating Fe{sub 3}O{sub 4} NPs with biocompatible stabilizers are required. We report a new method for preparing Fe{sub 3}O{sub 4} nanoparticles by co-precipitation within the pores of agar gel samples. Permeated agar gels were then dried and ground into a powder, yielding agar-conjugated Fe{sub 3}O{sub 4} nanoparticles. Samples were characterized using XRD, FTIR, TGA, TEM and SQUID. This method for preparing agar-coated Fe{sub 3}O{sub 4} nanoparticles is environmentally friendly, inexpensive and scalable.

  16. FeNi3/indium tin oxide (ITO) composite nanoparticles with excellent microwave absorption performance and low infrared emissivity

    International Nuclear Information System (INIS)

    Fu, Li-Shun; Jiang, Jian-Tang; Zhen, Liang; Shao, Wen-Zhu

    2013-01-01

    Highlights: ► Electrical conductivity and infrared emissivity can be controlled by ITO content. ► The infrared emissivity is the lowest when the mole ratio of In:Sn in sol is 9:1. ► The permittivity in microwave band can be controlled by the electrical conductivity. ► EMA performance is significantly influenced by the content of ITO phase. ► FeNi 3 /ITO composite particles are suitable for both infrared and radar camouflage. - Abstract: FeNi 3 /indium tin oxide (ITO) composite nanoparticles were synthesized by a self-catalyzed reduction method and a sol–gel process. The dependence of the content of ITO phase with the mole ratios of In:Sn of different sols was investigated. The relation between the electrical conductivity, infrared emissivity of FeNi 3 /ITO composite nanoparticles and the content of ITO phase was discussed. Electromagnetic wave absorption (EMA) performance of products was evaluated by using transmission line theory. It was found that EMA performance including the intensity and the location of effective band is significantly dependent on the content of ITO phase. The low infrared emissivity and superior EMA performance of FeNi 3 /ITO composite nanoparticles can be both achieved when the mole ratio of In:Sn in sol is 9:1.

  17. FeNi{sub 3}/indium tin oxide (ITO) composite nanoparticles with excellent microwave absorption performance and low infrared emissivity

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Li-Shun; Jiang, Jian-Tang [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China); Zhen, Liang, E-mail: lzhen@hit.edu.cn [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China); MOE Key Laboratory of Micro-systems and Micro-structures Manufacturing, Harbin Institute of Technology, Harbin 150080 (China); Shao, Wen-Zhu [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China)

    2013-03-01

    Highlights: Black-Right-Pointing-Pointer Electrical conductivity and infrared emissivity can be controlled by ITO content. Black-Right-Pointing-Pointer The infrared emissivity is the lowest when the mole ratio of In:Sn in sol is 9:1. Black-Right-Pointing-Pointer The permittivity in microwave band can be controlled by the electrical conductivity. Black-Right-Pointing-Pointer EMA performance is significantly influenced by the content of ITO phase. Black-Right-Pointing-Pointer FeNi{sub 3}/ITO composite particles are suitable for both infrared and radar camouflage. - Abstract: FeNi{sub 3}/indium tin oxide (ITO) composite nanoparticles were synthesized by a self-catalyzed reduction method and a sol-gel process. The dependence of the content of ITO phase with the mole ratios of In:Sn of different sols was investigated. The relation between the electrical conductivity, infrared emissivity of FeNi{sub 3}/ITO composite nanoparticles and the content of ITO phase was discussed. Electromagnetic wave absorption (EMA) performance of products was evaluated by using transmission line theory. It was found that EMA performance including the intensity and the location of effective band is significantly dependent on the content of ITO phase. The low infrared emissivity and superior EMA performance of FeNi{sub 3}/ITO composite nanoparticles can be both achieved when the mole ratio of In:Sn in sol is 9:1.

  18. Toward the direct deposition of L10 FePt nanoparticles

    International Nuclear Information System (INIS)

    Qiu Jiaoming; Judy, Jack H.; Weller, Dieter; Wang Jianping

    2005-01-01

    In this paper we report a technique that can directly fabricate L1 0 phase FePt nanoparticles. FePt nanoparticles were generated through gas-phase aggregation using a magnetron-sputtering-based nanocluster source. Following the source chamber, an online halogen-lamp heater was used for the L1 0 phase formation during the particles' flight in vacuum. Transmission electron microscopy and vibrating-sample magnetometer data verified the successful fabrication of the L1 0 phase FePt nanoparticles. The coercivity value at 300 K is 1100 Oe for the nanoparticles with online heating. Neon carrier gas was applied to manipulate FePt nanoparticle size and to enhance particle size uniformity. The size dependence of nanoparticle ordering was investigated

  19. Enhancement of the electrochemical performance in LiFePO4 cathode materials synthesized by using the sol-gel method

    Directory of Open Access Journals (Sweden)

    Kyong-Soo Hong

    2010-11-01

    Full Text Available LiFePO4 powders were synthesized by using the sol-gel and the solid-state reaction methods. The chemical states of Fe ions were studied by using XPS, and their electrochemical properties according to the oxidation states of Fe ions were compared. The average oxidation state of Fe ions in LiFePO4 powders synthesized by using the solid-state reaction method was found to be Fe3+, on the other hand, that of Fe ions synthesized by using the sol-gel method was found to be Fe2+. The obtained discharge capacities were 50 mAh/g and 120 mAh/g at a rate 0.1 C in LiFePO4 synthesized by using the solid-state reaction and sol-gel methods, respectively. Relatively a good cycling stability was observed in sol-gel prepared powder.

  20. A Discovery of Strong Metal-Support Bonding in Nanoengineered Au-Fe3O4 Dumbbell-like Nanoparticles by in Situ Transmission Electron Microscopy.

    Science.gov (United States)

    Han, Chang Wan; Choksi, Tej; Milligan, Cory; Majumdar, Paulami; Manto, Michael; Cui, Yanran; Sang, Xiahan; Unocic, Raymond R; Zemlyanov, Dmitry; Wang, Chao; Ribeiro, Fabio H; Greeley, Jeffrey; Ortalan, Volkan

    2017-08-09

    The strength of metal-support bonding in heterogeneous catalysts determines their thermal stability, therefore, a tremendous amount of effort has been expended to understand metal-support interactions. Herein, we report the discovery of an anomalous "strong metal-support bonding" between gold nanoparticles and "nano-engineered" Fe 3 O 4 substrates by in situ microscopy. During in situ vacuum annealing of Au-Fe 3 O 4 dumbbell-like nanoparticles, synthesized by the epitaxial growth of nano-Fe 3 O 4 on Au nanoparticles, the gold nanoparticles transform into the gold thin films and wet the surface of nano-Fe 3 O 4 , as the surface reduction of nano-Fe 3 O 4 proceeds. This phenomenon results from a unique coupling of the size-and shape-dependent high surface reducibility of nano-Fe 3 O 4 and the extremely strong adhesion between Au and the reduced Fe 3 O 4 . This strong metal-support bonding reveals the significance of controlling the metal oxide support size and morphology for optimizing metal-support bonding and ultimately for the development of improved catalysts and functional nanostructures.

  1. Liquid crystal based optical platform for the detection of Pb2+ ions using NiFe2O4 nanoparticles

    Directory of Open Access Journals (Sweden)

    Saman Zehra

    2018-06-01

    Full Text Available A simple, sensitive, selective and real time detection protocol was developed for Pb2+ ions in water using liquid crystals (LCs. In this method, NiFe2O4 nanoparticles were synthesized using chemical co-precipitation method. Crystallite size, morphological, functional groups and magnetization studies were confirmed using X-ray diffraction, Scanning Electron Microscopy, and Fourier transform infrared spectroscopy techniques, respectively. The nanoparticles were mono dispersed with average particle size of 20 ± 2 nm. The surfactant stabilized magnetic nanoparticles were incubated in liquid crystal based sensor system for the detection of Pb+2 ions. The bright to dark transition of LC was observed through optical microscope. When this system was further immersed with a solution containing Pb2+ ions, it caused homeotropic to planar orientation of LC. This interaction is attributed to the presence of abundant hydroxyl groups in such as M-OH, Fe-OH on the surface of spinel ferrites nanoparticles. These groups interact with metal ions at aqueous interface, causing disruption in LCs orientation giving bright texture. This sensor showed higher selectivity towards Pb2+ ions. The detection limit was estimated to be 100 ppb. The cheap and effective protocol reported here should make promising development of LC based sensor for lead ion detection. Keywords: Chemical co-precipitation method, Fourier transform infrared spectroscopy, Liquid crystals, Nanoparticles, Sensor, X-ray diffraction

  2. Anticancer activity of biologically synthesized silver and gold nanoparticles on mouse myoblast cancer cells and their toxicity against embryonic zebrafish

    Energy Technology Data Exchange (ETDEWEB)

    Ramachandran, Rajan [Centre for Advanced Studies in Botany, School of Life Sciences, University of Madras, Guindy Campus, Chennai 600 025, Tamil Nadu (India); Krishnaraj, Chandran [Department of Food Science & Technology, College of Agriculture & Life Sciences, Chonbuk National University, Jeonju 561-756 (Korea, Republic of); M/s. Eureka Forbes Ltd, R & D Centre, Kudlu, Bangalore (India); Sivakumar, Allur Subramaniyan [Department of Animal Biotechnology, Chonbuk National University, Jeonju 54896 (Korea, Republic of); Prasannakumar, Palaniappan [Advanced Biomedical Imaging Center, Department of Electronic Engineering, Chonbuk National University, Jeonju 54896 (Korea, Republic of); Abhay Kumar, V.K. [M/s. Eureka Forbes Ltd, R & D Centre, Kudlu, Bangalore (India); Shim, Kwan Seob [Department of Animal Biotechnology, Chonbuk National University, Jeonju 54896 (Korea, Republic of); Song, Chul-Gyu [Advanced Biomedical Imaging Center, Department of Electronic Engineering, Chonbuk National University, Jeonju 54896 (Korea, Republic of); Yun, Soon-Il, E-mail: siyun@jbnu.ac.kr [Department of Food Science & Technology, College of Agriculture & Life Sciences, Chonbuk National University, Jeonju 561-756 (Korea, Republic of)

    2017-04-01

    The aim of this study was to evaluate the anticancer activity of bioinspired silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) against mouse myoblast cancer cells (C{sub 2}C{sub 12}). Both AgNPs and AuNPs were biologically synthesized using Spinacia oleracea Linn., aqueous leaves extract. UV–Vis. spectrophotometer, high resolution-transmission electron microscopy (HR-TEM), field emission-scanning electron microscopy (FE-SEM) and X-ray diffraction (XRD) studies supported the successful synthesis of AgNPs and AuNPs. Both these NPs have shown cytotoxicity against C{sub 2}C{sub 12} cells even at very low concentration (5 μg/mL). Acridine orange/Ethidium bromide (AO/EB) dual staining confirmed the apoptotic morphological features. The levels of caspase enzymes (caspase-3 and caspase-7) were significantly up-regulated in NPs treated myoblast cells than the plant extract. Furthermore, in zebrafish embryo toxicity study, AgNPs showed 100% mortality at 3 μg/mL concentration while AuNPs exhibited the same at much higher concentration (300 mg/mL). Taken together, these results provide a preliminary guidance for the development of biomaterials based drugs to fight against the fatal diseases for example cancer. - Highlights: • Anticancer activity was done for the first time against mouse myoblast cells. • AgNPs showed 100% growth inhibition against C{sub 2}C{sub 12} cells at 20 μg/mL concentration. • AO/EB dual staining and caspase assays confirmed the apoptotic features. • Nanoparticles treated embryos showed yolk sac edema and tail malformation. • AgNPs were found to be more toxic to embryonic zebrafishes than the AuNPs.

  3. Anticancer activity of biologically synthesized silver and gold nanoparticles on mouse myoblast cancer cells and their toxicity against embryonic zebrafish

    International Nuclear Information System (INIS)

    Ramachandran, Rajan; Krishnaraj, Chandran; Sivakumar, Allur Subramaniyan; Prasannakumar, Palaniappan; Abhay Kumar, V.K.; Shim, Kwan Seob; Song, Chul-Gyu; Yun, Soon-Il

    2017-01-01

    The aim of this study was to evaluate the anticancer activity of bioinspired silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) against mouse myoblast cancer cells (C 2 C 12 ). Both AgNPs and AuNPs were biologically synthesized using Spinacia oleracea Linn., aqueous leaves extract. UV–Vis. spectrophotometer, high resolution-transmission electron microscopy (HR-TEM), field emission-scanning electron microscopy (FE-SEM) and X-ray diffraction (XRD) studies supported the successful synthesis of AgNPs and AuNPs. Both these NPs have shown cytotoxicity against C 2 C 12 cells even at very low concentration (5 μg/mL). Acridine orange/Ethidium bromide (AO/EB) dual staining confirmed the apoptotic morphological features. The levels of caspase enzymes (caspase-3 and caspase-7) were significantly up-regulated in NPs treated myoblast cells than the plant extract. Furthermore, in zebrafish embryo toxicity study, AgNPs showed 100% mortality at 3 μg/mL concentration while AuNPs exhibited the same at much higher concentration (300 mg/mL). Taken together, these results provide a preliminary guidance for the development of biomaterials based drugs to fight against the fatal diseases for example cancer. - Highlights: • Anticancer activity was done for the first time against mouse myoblast cells. • AgNPs showed 100% growth inhibition against C 2 C 12 cells at 20 μg/mL concentration. • AO/EB dual staining and caspase assays confirmed the apoptotic features. • Nanoparticles treated embryos showed yolk sac edema and tail malformation. • AgNPs were found to be more toxic to embryonic zebrafishes than the AuNPs.

  4. Smooth and rapid microwave synthesis of MIL-53(Fe) including superparamagnetic γ-Fe2O3 nanoparticles

    Science.gov (United States)

    Wengert, Simon; Albrecht, Joachim; Ruoss, Stephen; Stahl, Claudia; Schütz, Gisela; Schäfer, Ronald

    2017-12-01

    MIL-53(Fe) linked to superparamagnetic γ-Fe2O3 nanoparticles was created using time-efficient microwave synthesis. Intermediates as well as the final product have been characterized by Dynamic Light Scattering (DLS), Infrared Spectroscopy (FTIR) and Thermal Gravimetric Analysis (TGA). It is found that this route allows the production of Fe nanoparticles with typical sizes of about 80 nm that are embedded inside the metal-organic structures. Detailed magnetization measurements using SQUID magnetometry revealed a nearly reversible magnetization loop indicating essentially superparamagnetic behavior.

  5. Spin reorientation in α-Fe2O3 nanoparticles induced by interparticle exchange interactions in alpha-Fe2O3/NiO nanocomposites

    DEFF Research Database (Denmark)

    Frandsen, Cathrine; Lefmann, Kim; Lebech, Bente

    2011-01-01

    We report that the spin structure of alpha-Fe2O3 nanoparticles rotates coherently out of the basal (001) plane at low temperatures when interacting with thin plate-shaped NiO nanoparticles. The observed spin reorientation (up to similar to 70 degrees) in alpha-Fe2O3 nanoparticles has, in appearan......, similarities to the Morin transition in bulk alpha-Fe2O3, but its origin is different-it is caused by exchange coupling between aggregated nanoparticles of alpha-Fe2O3 and NiO with different directions of easy axes of magnetization.......We report that the spin structure of alpha-Fe2O3 nanoparticles rotates coherently out of the basal (001) plane at low temperatures when interacting with thin plate-shaped NiO nanoparticles. The observed spin reorientation (up to similar to 70 degrees) in alpha-Fe2O3 nanoparticles has, in appearance...