scholarly journals Preparation of Silver Nanostructures from Bicontinuous Microemulsions

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
M. A. Pedroza-Toscano ◽  
M. Rabelero-Velasco ◽  
R. Díaz de León ◽  
H. Saade ◽  
R. G. López ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Silver Nanoparticles ◽  
Average Length ◽  
Sodium Dodecylsulfate ◽  
Average Diameter ◽  
Silver Nanostructures ◽  
X Ray Diffraction ◽  
One Dimensional ◽  
X Ray ◽  
Reverse Microemulsions

Precipitation of silver nanoparticles at 70°C was carried out by dosing a 1.3 M sodium borohydride aqueous solution over bicontinuous microemulsions formed with a mixture of sodium bis(2-ethylhexyl) sulfosuccinate (AOT) and sodium dodecylsulfate (SDS) as surfactants, a 0.5 M silver nitrate aqueous solution, and toluene. Weight ratios of 2.5/1 and 3/1 AOT/SDS were used in the precipitation reactions. Silver nanoparticles were characterized by transmission electronic microscopy, X-ray diffraction, and atomic absorption spectroscopy. A mixture of isolated spheroidal nanoparticles (≈15 wt.%) with an average diameter around 10 nm and wormlike structures (≈85 wt.%) with an average length close to 480 nm and an average diameter ca. 40 nm was obtained, regardless of the AOT/SDS ratio. Higher yields were obtained compared with those reported when reverse microemulsions were employed. Formation of wormlike structures was ascribed to one-dimensional aggregation of crystal and particles within the channels of bicontinuous microemulsions, which performed as templates.

Preparation of PCL/PVP/Ag Nanofiber Membranes by Electrospinning Method

2012 ◽  
Vol 268-270 ◽  
pp. 580-583 ◽  
Author(s):  
Yong Tang Jia ◽  
Cui Wu ◽  
Feng Chun Dong ◽  
Gang Huang ◽  
Xian Hua Zeng
Keyword(s):  
Silver Nanoparticles ◽  
Photoelectron Spectroscopy ◽  
Composite Nanofibers ◽  
Average Diameter ◽  
Vinyl Pyrrolidone ◽  
X Ray Diffraction ◽  
X Ray ◽  
Electrospinning Method ◽  
Nanofiber Membranes ◽  
Poly Vinyl Pyrrolidone

The composite nanofiber membranes of poly (ε-caprolactone)/poly(vinyl pyrrolidone) (PCL/PVP) containing silver nanoparticles were prepared by electrospinning method. The morphology of composite nanofibers was characterized by scanning electron microscopy (SEM). The silver nanoparticles on the electrospun fibers were characterized by X-Ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The contact angle and water uptake of PCL/PVP/Ag nanofiber membranes were measured. The SEM photos indicated that the average diameter of the fibers was significantly decreased with the addition of silver nanoparticles. The X-Ray images showed that Ag nanoparticles were distributed on the surface of nanofiber membranes. When the PVP mole ratio was higher than 15%, the nanofiber membranes showed good hydrophilic property. The PCL/PVP/Ag nanofiber membranes could be applied to prepare wound dressing.

scholarly journals Biosynthesis of Anisotropic Silver Nanoparticles byBhargavaea indicaand Their Synergistic Effect with Antibiotics against Pathogenic Microorganisms

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Priyanka Singh ◽  
Yeon Ju Kim ◽  
Hina Singh ◽  
Ramya Mathiyalagan ◽  
Chao Wang ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Vibrio Parahaemolyticus ◽  
Size Range ◽  
Average Diameter ◽  
Pathogenic Microorganisms ◽  
X Ray Diffraction ◽  
X Ray ◽  
Extracellular Biosynthesis ◽  
Predominant Component ◽  
Transmission Electron

The strainBhargavaea indicaDC1 isolated from four-year-oldP. ginsengrhizospheric soil was used to perform rapid and extracellular biosynthesis of anisotropic silver nanoparticles. The ultraviolet-visible (UV-vis) spectra of the reaction mixture containing silver nanoparticles showed a peak at 460 nm, corresponding to the surface plasmon absorbance of silver nanoparticles. Field-emission transmission electron microscopy (FE-TEM) structural characterization revealed the nanobar, pentagon, spherical, icosahedron, hexagonal, truncated triangle, and triangular nanoparticles, with the size range from 30 to 100 nm. The energy-dispersive X-ray (EDX) analysis and elemental mapping results also confirmed that the silver was the predominant component of isolated nanoparticles. The X-ray diffraction (XRD) results correspond to the purity of silver nanoparticles and dynamic light scattering (DLS) result indicated that the average diameter of particles was 111.6 nm. In addition, enhancement in antimicrobial activity of commercial antibiotics was observed against various pathogenic microorganisms such asVibrio parahaemolyticus, Salmonella enterica, Staphylococcus aureus, Bacillus anthracis, Bacillus cereus, Escherichia coli, andCandida albicans.

Study on Synthesis Nanomicrostructures of Zinc Borate (Zn3B6O12•3.5H2O) with Different Morphologies

2011 ◽  
Vol 236-238 ◽  
pp. 1687-1691 ◽  
Author(s):  
Hui Ren ◽  
You Ming Cao ◽  
Zhou Qiao Lei
Keyword(s):  
Electron Microscopy ◽  
Aqueous Solution ◽  
Scanning Electron Microscopy ◽  
Raw Materials ◽  
Average Length ◽  
Zinc Borate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

The crystal zinc borate (Zn3B6O12·3.5H2O) nano-strips and nano-flakes were successfully prepared by a wet method using boric acid (H3BO3) and Zn(NO3)2·H2O as raw materials in situ aqueous solution, and triethanolamine as the modifying agent. The nano/microstructures and morphologies of the as-obtained samples were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM) equipped with an energy dispersive X-ray spectrometer (EDS) and thermogravimetric analysis (TGA). It had been found that the as-prepared materials displayed nanostrips with average length from 100 to 200nm and the thicknesses about 30nm as well as nanoflakes with diameter about 4μm and thickness about several nanometers morphology.

Preparation of Ultrafine Poly(ε-Caprolactone) Fibers Containing Silver Nanoparticles via Electrospinning Method

2011 ◽  
Vol 332-334 ◽  
pp. 1235-1238 ◽  
Author(s):  
Yong Tang Jia ◽  
Qing Qing Liu ◽  
Xiang Ying Zhu
Keyword(s):  
Electron Microscopy ◽  
Silver Nanoparticles ◽  
Ag Nanoparticles ◽  
Average Diameter ◽  
Contact Angles ◽  
Electrospun Fibers ◽  
X Ray Diffraction ◽  
X Ray ◽  
Electrospinning Method ◽  
Scanning Electron

Electrospun poly(ε-caprolactone) (PCL) fibers containing silver nanoparticles were successfully prepared from PCL solutions added silver collide. The silver collide were obtained by N, N-dimethylformamide (DMF) reducing silver nitrate (AgNO3). The effects of PCL concentration and the content of silver nanoparticles on composite fibers morphology were characterized by field-emission scanning electron microscopy (FESEM). The existence of Ag nanoparticles on the electrospun fibers was approved by X-Ray diffraction (XRD). Simultaneously, the contact angles of fiber membranes were measured. The results indicated that uniform fibers were obtained when PCL concentration was 9wt%, the average diameter of fiber was significantly decreased as increasing the amount of silver collide, and Ag nanoparticles were successfully incorporated into the PCL fibers.

Synthesis and Structural Characterization of Mo-Ni-W Oxide Nanostructures

2008 ◽  
Vol 8 (6) ◽  
pp. 2983-2989 ◽  
Author(s):  
F. Paraguay-Delgado ◽  
R. Huirache-Acuña ◽  
M. Jose-Yacaman ◽  
G. Alonso-Nuñez
Keyword(s):  
Electron Microscopy ◽  
Average Length ◽  
Average Diameter ◽  
Atomic Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Oxide Nanostructures ◽  
Transmission Electron ◽  
Segregated Structure

In this work, we report the synthesis and characterization of Mo-Ni-W oxides. The precursor was prepared from an aqueous solution of ammonium heptamolibdate, ammonium metatungstate, and nickel nitrate with an atomic ratio of 1:1:1 (Mo:W:Ni). The solution was then transferred to a Teflon-lined stainless steel autoclave and heated to 200 °C and left at this temperature for 48 h. The resulting material was then washed and dried. The morphology and elemental composition were studied by scanning electron microscopy, transmission electron microscopy, energy dispersive X-ray spectroscopy, and X-ray diffraction. The porosity was studied by the Brunauer, Emmett, and Teller method. The materials synthesized at 200 °C remained amorphous and had a specific surface area of 114 m2/g with pore size of 34 Å. The average length was 1 μm and the average diameter was 60 nm. The crystalline phase of synthesized material corresponded to W0.4Mo0.6O3 and WO3. After annealing at 550 °C for two hours, the material was polycrystalline with a segregated structure of MoO3, WO3; NiMoO4 was observed. The sublimation of the molybdenum oxide was evident when annealed at 900 °C for two hours and finally two crystalline phases of material remained; roundish WO3 and elongated particles of NiWO4.

Structural Study of a new Compound Based on Acid 1,4-Cyclohexanedicarboxylic (1,4-CDC)

2010 ◽  
Vol 6 (1) ◽  
pp. 891-896
Author(s):  
Manel Halouani ◽  
M. Dammak ◽  
N. Audebrand ◽  
L. Ktari
Keyword(s):  
Aqueous Solution ◽  
Water Molecules ◽  
Carboxyl Group ◽  
X Ray Diffraction ◽  
Compound I ◽  
Unit Cell Parameters ◽  
Monoclinic System ◽  
X Ray ◽  
Cell Parameters ◽  
Cyclohexanedicarboxylic Acid

One nickel 1,4-cyclohexanedicarboxylate coordination polymers, Ni2 [(O10C6H4)(COO)2].2H2O  (I), was hydrothermally synthesized from an aqueous solution of Ni (NO3)2.6H2O, (1,4-CDC) (1,4-CDC = 1,4-cyclohexanedicarboxylic acid) and tetramethylammonium nitrate. Compound (I) crystallizes in the monoclinic system with the C2/m space group. The unit cell parameters are a = 20.1160 (16) Å, b = 9.9387 (10) Å, c = 6.3672 (6) Å, β = 97.007 (3) (°), V= 1263.5 (2) (Å3) and Dx= 1.751g/cm3. The refinement converged into R= 0.036 and RW = 0.092. The structure, determined by single crystal X-ray diffraction, consists of two nickel atoms Ni (1) and Ni (2). Lots of ways of which is surrounded by six oxygen atoms, a carboxyl group and two water molecules.

scholarly journals Leaching Titaniferous Magnetite Concentrate by Alkaline Aqueous Solution

2021 ◽  
Author(s):  
Ke Guo ◽  
Shaoyan Wang ◽  
Renfeng Song ◽  
Zhiqiang Zhang
Keyword(s):  
Aqueous Solution ◽  
Alkali Concentration ◽  
Water Usage ◽  
X Ray Diffraction ◽  
High Concentration ◽  
X Ray ◽  
Iron Concentrate ◽  
Titaniferous Magnetite ◽  
Magnetite Concentrate ◽  
Kinetics Of

AbstractLeaching titaniferous magnetite concentrate with alkali solution of high concentration under high temperature and high pressure was utilized to improve the grade of iron in iron concentrate and the grade of TiO2 in titanium tailings. The titaniferous magnetite concentrate in use contained 12.67% TiO2 and 54.01% Fe. The thermodynamics of the possible reactions and the kinetics of leaching process were analyzed. It was found that decomposing FeTiO3 with NaOH aqueous solution could be carried out spontaneously and the reaction rate was mainly controlled by internal diffusion. The effects of water usage, alkali concentration, reaction time, and temperature on the leaching procedure were inspected, and the products were characterized by X-ray diffraction, scanning electron microscope, and energy dispersive spectroscopy, respectively. After NaOH leaching and magnetic separation, the concentrate, with Fe purity of 65.98% and Fe recovery of 82.46%, and the tailings, with TiO2 purity of 32.09% and TiO2 recovery of 80.79%, were obtained, respectively.

Formalism for the determination of intermediate stress gradients using X-ray diffraction

2009 ◽  
Vol 42 (2) ◽  
pp. 192-197 ◽  
Author(s):  
Thomas Gnäupel-Herold
Keyword(s):  
Lattice Strain ◽  
Narrow Line ◽  
X Ray Diffraction ◽  
Beam Spot ◽  
Strain Measurements ◽  
One Dimensional ◽  
X Ray ◽  
Stress Gradients ◽  
Shaped Beam

A method is outlined that allows the determination of one-dimensional stress gradients at length scales greater than 0.2 mm. By using standard four-circle X-ray diffractometer equipment and simple aperture components, length resolutions down to 0.05 mm in one direction can be achieved through constant orientation of a narrow, line-shaped beam spot. Angle calculations are given for the adjustment of goniometer angles, and for the effective azimuth and tilt of the scattering vector for general angle settings in a four-circle goniometer. The latter is necessary for the computation of stresses from lattice strain measurements.

Removal of Heavy Metals from Aqueous Solution by Hydroxyapatite/Chitosan Composite

2013 ◽  
Vol 789 ◽  
pp. 176-179 ◽  
Author(s):  
Eny Kusrini ◽  
Nofrijon Sofyan ◽  
Dwi Marta Nurjaya ◽  
Santoso Santoso ◽  
Dewi Tristantini
Keyword(s):  
Heavy Metals ◽  
Aqueous Solution ◽  
Metal Ions ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Removal Of Heavy Metals ◽  
Sem Micrograph ◽  
Pseudo Second Order ◽  
Chitosan Composite

Hydroxyapatite/chitosan (HApC) composite has been prepared by precipitation method and used for removal of heavy metals (Cr6+, Zn2+and Cd2+) from aqueous solution. The HAp and 3H7C composite with HAp:chitosan ratio of 3:7 (wt%) were characterized by Fourier transform infrared spectroscopy, X-ray diffraction and scanning electron microscopy-energy dispersive X-ray spectroscopy. The SEM results showed that HAp is spherical-shaped and crystalline, while chitosan has a flat structure. SEM micrograph of 3H7C composite reveals crystalline of HAp uniformly spread over the surface of chitosan. The crystal structure of HAp is maintained in 3H7C composite. Chitosan affects the adsorption capacity of HAp for heavy metal ions; it binds the metal ions as well as HAp. The kinetic data was best described by the pseudo-second order. Surface adsorption and intraparticle diffusion take place in the mechanism of adsorption process. The binding of HAp powder with chitosan made the capability of composite to removal of Cr6+, Zn2+and Cd2+from aqueous solution effective. The order of removal efficiency (Cr6+> Cd2+> Zn2+) was observed.

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