scholarly journals Preparation and Characterization of Magnetic Chitosan Microcapsules

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Xiaopeng Xiong ◽  
Yong Wang ◽  
Weiwei Zou ◽  
Jiangjiang Duan ◽  
Yun Chen
Keyword(s):  
Magnetic Properties ◽  
Strong Interaction ◽  
Liquid Paraffin ◽  
Hollow Microspheres ◽  
Composite Particles ◽  
Cross Link ◽  
Magnetic Chitosan ◽  
Starting Solution ◽  
Dense Shell

By dispersing aqueous precipitant in liquid paraffin to prepare a W/O emulsion then adding chitosan (CS) solution, CS microcapsules have been successfully prepared. It is a facile way to prepare polymer microcapsules by using aqueous precipitant or nonsolvent as template, which avoids the removal of template and would free from the necessity to cross-link the microcapsule as usual methods to directly form dense shell. The hollow feature of the obtained materials is revealed. The diameter of the microcapsules ranges from severalμm to over 100 μm. Magnetic CS microcapsules have been prepared in this way when Fe3+and Fe2+were mixed with CS to prepare a mixture starting solution. The appearance and microstructure of the composite microcapsules were studied. The results indicate that the formed Fe3O4nanoparticles are embedded in the CS matrix evenly due to strong interaction between the Fe3O4nanoparticles and the CS molecules. The Fe3O4content and the magnetic properties of the composite microcapsule were measured. The composite microcapsules were calcined in air at 700°C to prepare pure inorganic hollow microspheres. It is general to prepare hollow polymeric or composite particles by using this method.

Characterization of Metallo-porphine Monolayer and Bilayer on Ag(111): Screening of Substrate Effects

2014 ◽  
Vol 618 ◽  
pp. 225-232
Author(s):  
Yu Du ◽  
Xiao Qing Tian ◽  
Jian Bin Xu
Keyword(s):  
Magnetic Properties ◽  
Strong Interaction ◽  
Magnetic Moment ◽  
Adsorbed Molecule ◽  
Bottom Layer ◽  
First Principle ◽  
Substrate Effects ◽  
Substrate Interaction ◽  
Structural Distortions

The structures and magnetic properties of monolayer and bilayer of transitional metallo-porphine (MP) species (M = Mn, Fe, Co, Ni, Cu) on the Ag (111) substrate are investigated by DFT based first-principle method. The MP monolayer has a distortion about 10° towards the substrate due to strong interaction between adsorbed molecule and substrate. The molecule-substrate interaction could quench the magnetic moment of the adsorbed molecule. For MP bilayer adsorption on the Ag (111), the top layer remains its planar structure and magnetic moment due to the screening of substrate effects by bottom layer, meanwhile the bottom layer has strong structural distortions and obvious variations of magnetic moment.

Preparation and Characterization of Integral Hollow Microspheres of Nickel Hydroxide and Nickel Oxide

2007 ◽  
Vol 121-123 ◽  
pp. 187-190 ◽  
Author(s):  
Xiao Feng Wu ◽  
Yun Fa Chen ◽  
Qun Yan Li ◽  
L.Q. Wei
Keyword(s):  
Nickel Oxide ◽  
Nickel Hydroxide ◽  
Hollow Spheres ◽  
Hollow Microspheres ◽  
Nickel Nitrate ◽  
Composite Particles ◽  
Nickel Salt ◽  
Core Method ◽  
Hydrolysis Of

Hollow microspheres of nickel hydroxide and nickel oxide were prepared with as-synthesized PS/Ni(OH)2 composite particles by sacrificing core method, respectively. The composite particles were synthesized by deposition of the Ni(OH)2 nanoflakelets formed by the hydrolysis of nickel nitrate onto the surfaces of polystyrene (PS) particles. The effects of different concentrations of nickel salt and urea on the deposition of the nanoflakelets of nickel hydroxide were studied. It was found that the uniform nanoflakelets were deposited on the polystyrene particles under the conditions of the 4╳10-3 M nickel salt and 0.667M urea. Compared with the directly calcinating of composite particles, Integral hollow microspheres of nickel hydroxide were attained by removal of cores of polystyrene in composite particles with toluene and NiO hollow microspheres by calcinating of these Ni(OH)2 hollow spheres in oven at 600°C for 2h.

AEM analysis of crystallization in Ti-based amorphous alloys

1983 ◽  
Vol 41 ◽  
pp. 270-271
Author(s):  
A.R. Pelton ◽  
A.F. Marshall ◽  
Y.S. Lee
Keyword(s):  
Magnetic Properties ◽  
Amorphous Alloys ◽  
Amorphous Materials ◽  
Isothermal Annealing ◽  
Amorphous Matrix ◽  
Nucleation And Growth ◽  
Current Interest ◽  
Amorphous Films ◽  
Electrical And Magnetic Properties

Amorphous materials are of current interest due to their desirable mechanical, electrical and magnetic properties. Furthermore, crystallizing amorphous alloys provides an avenue for discerning sequential and competitive phases thus allowing access to otherwise inaccessible crystalline structures. Previous studies have shown the benefits of using AEM to determine crystal structures and compositions of partially crystallized alloys. The present paper will discuss the AEM characterization of crystallized Cu-Ti and Ni-Ti amorphous films.Cu60Ti40: The amorphous alloy Cu60Ti40, when continuously heated, forms a simple intermediate, macrocrystalline phase which then transforms to the ordered, equilibrium Cu3Ti2 phase. However, contrary to what one would expect from kinetic considerations, isothermal annealing below the isochronal crystallization temperature results in direct nucleation and growth of Cu3Ti2 from the amorphous matrix.

scholarly journals Green synthesis and characterization of hexaferrite strontium-perovskite strontium photocatalyst nanocomposites

2020 ◽  
Vol 43 (1) ◽  
pp. 26-42 ◽  
Author(s):  
Zahra Hajian Karahroudi ◽  
Kambiz Hedayati ◽  
Mojtaba Goodarzi
Keyword(s):  
Magnetic Properties ◽  
Green Synthesis ◽  
Sol Gel ◽  
Synthesis Method ◽  
Combustion Method ◽  
Lemon Juice ◽  
X Ray Diffraction ◽  
X Ray ◽  
Auto Combustion

AbstractThis study presents a preparation of SrFe12O19– SrTiO3 nanocomposite synthesis via the green auto-combustion method. At first, SrFe12O19 nanoparticles were synthesized as a core and then, SrTiO3 nanoparticles were prepared as a shell for it to manufacture SrFe12O19–SrTiO3 nanocomposite. A novel sol-gel auto-combustion green synthesis method has been used with lemon juice as a capping agent. The prepared SrFe12O19–SrTiO3 nanocomposites were characterized by using several techniques to characterize their structural, morphological and magnetic properties. The crystal structures of the nanocomposite were investigated via X-ray diffraction (XRD). The morphology of SrFe12O19– SrTiO3 nanocomposite was studied by using a scanning electron microscope (SEM). The elemental composition of the materials was analyzed by an energy-dispersive X-ray (EDX). Magnetic properties and hysteresis loop of nanopowder were characterized via vibrating sample magnetometer (VSM) in the room temperature. Fourier transform infrared spectroscopy (FTIR) spectra of the samples showed the molecular bands of nanoparticles. Also, the photocatalytic behavior of nanocomposites has been checked by the degradation of azo dyes under irradiation of ultraviolet light.

Synthesis and Structural Characterization of Zinc and Magnesium Doped Hydroxyapatite

2012 ◽  
Vol 531-532 ◽  
pp. 250-253 ◽  
Author(s):  
Hong Quan Zhang ◽  
Ming Zhang ◽  
Lu Wei Fu ◽  
Yu Ning Cheng
Keyword(s):  
Hydrothermal Treatment ◽  
Structural Characterization ◽  
Chemical Precipitation ◽  
Precipitation Method ◽  
Starting Solution ◽  
Wet Chemical ◽  
Zn Ions ◽  
Wet Chemical Precipitation ◽  
Surface Of Crystals

Zn or Mg ions doped hydroxyapatite (HA) particles were successfully developed by introducing various concentration of Zn or Mg in the starting solution using wet chemical precipitation method and followed a hydrothermal treatment. The products were identified as HA by XRD and FTIR, and the precipitated particles had a rod-like morphology. All the products for Mg and Zn ions concentration in the preparation solution less than 40 mol% were identified as HA. Substitution of Mg and Zn in HA crystal would impair the crystallization of HA and significantly reduce the length of a, c values of HA unit cell, which clearly demonstrated that Mg or Zn ions were structurally incorporated into the apatite crystals, they were not just absorbed on the surface of crystals.

Structure Characterization of Amorphous CoxGd1−x Nanowires and Magnetic Properties of Their Arrays

2009 ◽  
Vol 113 (39) ◽  
pp. 16934-16938 ◽  
Author(s):  
S. Y. Liu ◽  
A. K. Soh ◽  
L. Hong ◽  
L. Lu
Keyword(s):  
Magnetic Properties ◽  
Structure Characterization
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