Preparation and Application of Carboxyl-Functioned Magnetic Nanoparticles for Arylsulfatase Immobilization

2016 ◽  
Vol 13 (10) ◽  
pp. 7408-7415
Author(s):  
Yongxing Li ◽  
Qiong Xiao ◽  
Qin Yin ◽  
Hui Ni ◽  
Yanbing Zhu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Magnetic Nanoparticles ◽  
Vibrating Sample Magnetometry ◽  
X Ray Diffraction ◽  
Sulfate Ester ◽  
Xrd Pattern ◽  
X Ray ◽  
Transmission Electron ◽  
Mean Diameter ◽  
Diffraction Patterns

Arylsulfatase, one of a few enzymes that can enhance the gelling strength of agar by cleaving the sulfate ester bonds in agar, was covalently immobilized with carboxyl functioned magnetic nanoparticles (CMNPs). The resultant CMNPs and immobilized arylsulfatase were characterized by transmission electron microscopy (TEM), Dynamic Light scattering (DLS), X-ray diffraction (XRD), vibrating sample magnetometry (VSM) and thermogravimetric analysis (TGA). The TEM result indicated that the CMNPs and immobilized arylsulfatase had a similar mean particle size of 10 nm. The arylsulfatase-CMNPs had a mean diameter of 1200 nm in aqueous solution determined by the DLS, which was much bigger than the CMNPs (433.6 nm). The different sizes demonstrated that the arylsulfatase was coated on CMNPs successfully. XRD showed that diffraction patterns of the CMNPs and arylsulfatase-CMNPs were close to the standard XRD pattern of Fe3O4. Saturation magnetizations were 52.1 emu/g for carriers and 47.9 emu/g for immobilized arylsulfatase, which indicated that the particles had superparamagnetic characteristics. The TGA revealed that the amount of arylsulfatase bound to the surface of CMNPs was 5.65%. The arylsulfatase exhibited better thermal stability and reusability after immobilization, the immobilized arylsulfatase can retain more than 50% enzyme activity up to the 9th cycle.

Hydrothermal Synthesis and Characterization of BiFeO3 Polyhedral Crystallites

2012 ◽  
Vol 174-177 ◽  
pp. 508-511
Author(s):  
Lin Lin Yang ◽  
Yong Gang Wang ◽  
Yu Jiang Wang ◽  
Xiao Feng Wang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Synthesis And Characterization ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

BiFeO3 polyhedrons had been successfully synthesized via a hydrothermal method. The as-prepared products were characterized by power X-ray diffraction (XRD) pattern, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The possible mechanisms for the formation of BiFeO3 polyhedrons were discussed. Though comparison experiments, it was found that the kind of precursor played a key role on the morphology control of BiFeO3 crystals.

SOLVOTHERMAL SYNTHESIS OF UNIFORM MAGNETITE MICROSPHERES

2010 ◽  
Vol 03 (02) ◽  
pp. 125-129 ◽  
Author(s):  
CAIQUAN ZHANG ◽  
YALI CUI ◽  
DIDI ◽  
KUNPING YAN ◽  
CHAO CHEN ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Solvothermal Synthesis ◽  
Solvothermal Method ◽  
Vibrating Sample Magnetometry ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Magnetite Particles ◽  
Uniform Particle Size ◽  
Scanning Electron

Facile procedures to synthesize large quantities of uniform and well dispersed magnetite particles in water were developed through a solvothermal method. Magnetite microspheres were obtained by using FeCl 3 · 6H 2 O , urea and polyethylene glycol as the starting materials in ethylene glycol at 200°C for 8 h. The samples were characterized by using X-ray diffraction, transmission electron microscopy, scanning electron microscopy and vibrating sample magnetometry. Experimental results revealed that the particles were well dispersed with uniform particle size and diameters in the range 260 to 280 nm. The saturation magnetization value was 71.5 emu/g with negligible remanence.

Synthesis of Ni-Mo-W Sulfide Nanorods as Catalyst for Hydrodesulfurization of Dibenzothiophene

2008 ◽  
Vol 8 (12) ◽  
pp. 6406-6413 ◽  
Author(s):  
F. Paraguay-Delgado ◽  
R. García-Alamilla ◽  
J. A. Lumbreras ◽  
E. Cizniega ◽  
G. Alonso-Núñez
Keyword(s):  
Electron Microscopy ◽  
Physical Adsorption ◽  
Atomic Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Oxide Precursor ◽  
Transmission Electron ◽  
Adsorption Of Nitrogen ◽  
Diffraction Patterns ◽  
Scanning Electron

Two trimetallic sulfurs, MoWNiS and MoWSNi, were synthesized to be used as a catalyst in hydrodesulfurization reactions. The mixed oxide mesoporous nanostructured MoO3-WO3 with an Mo:W atomic ratio of 1:1 was used as the precursor. The first catalyst was prepared by impregnating nickel in the oxide precursor and then subsequent sulfiding with an H2S/H2 mix at 400 °C for 2 hours. The second catalyst was prepared by sulfiding the precursor and then impregnating the nickel, and finally reducing the material with a H2/N2 at 350 °C. In both catalysts the Mo:W:Ni atomic ratio was maintained at 1:1:0.5. The materials obtained were characterized by physical adsorption of nitrogen, X-ray diffraction, scanning electron microscopy, transmission electron microscopy. Furthermore, the materials obtained were evaluated by a dibenzothiophene hydrodesulfuration reaction. The diffraction patterns show that both materials are polycrystalline and mainly of MoS2 and WS2 phases.

Paper 24: Dry Wear of Steel as Revealed by Electron Microscopy and X-Ray Diffraction

1967 ◽  
Vol 182 (14) ◽  
pp. 201-213
Author(s):  
T. F. J. Quinn
Keyword(s):  
Electron Microscopy ◽  
Medium Carbon Steel ◽  
X Ray Diffraction ◽  
Medium Carbon ◽  
X Ray ◽  
Ambient Temperatures ◽  
Transmission Electron ◽  
Steel Aisi ◽  
Diffraction Patterns ◽  
Fatigue Failures

Low-alloy, medium-carbon steel (AISI 4340) pins have been worn against discs of the same material at various loads under unlubricated (‘dry’) sliding conditions. Shadowed carbon replicas have been obtained from the surfaces of selected pins and discs. Transmission electron microscopy of these replicas revealed several interesting features, the most interesting being the presence of reproducible crack systems occurring in those parts of the surface at which the wear is taking place. These cracks are very similar to those obtained in fatigue failures. X-ray diffraction patterns were also obtained from these specimens, and from the corresponding wear debris. These indicated that oxidation had occurred at temperatures considerably in excess of the measured ambient temperatures. The various topographic and crystallographic features revealed by the electron microscopy and X-ray diffraction techniques are discussed in relation to a possible mechanism of ‘dry’ wear

scholarly journals Investigation of Lithiated Carbons by Transmission Electron Microscopy and X-Ray Diffraction Analysis

1998 ◽  
Vol 548 ◽  
Author(s):  
T. D. Tran ◽  
X. Y. Song ◽  
K. Kinoshita
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Carbon Black ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Lattice Image ◽  
X Ray ◽  
Storage Mechanism ◽  
Transmission Electron ◽  
Diffraction Patterns

ABSTRACTThe microstructures of lithiated synthetic graphite and carbon black were studied by high- resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD) analysis. Information about the crystal structure of carbon containing various Li compositions can provide useful insights to our understanding of the Li storage mechanism in carbonaceous materials. Samples with compositions of Li0.93C6or Li0.45C6 were found to contain both stage-one and stage-two compounds. These observations are consistent with XRD data. The changes in sample microstructure as the results of lithiation and exposure to electron irradiation were observed by TEM and recorded over several minutes in the microscope environment. Selected area electron diffraction patterns indicated that the lithiated samples quickly changed composition to LiC 24, which appeared to dominate during the brief analysis period. The layer planes in the lattice image of a disordered carbon black after Li insertion are poorly defined, and changes in the microstructure of these lithiated carbons was not readily apparent. Observations on these lithium intercalation compounds as well as the limitation of the experimental procedure will be presented.

The Formation of New Periodicities after N-Implantation in 4H- and 6H-SiC Samples

2013 ◽  
Vol 740-742 ◽  
pp. 447-450
Author(s):  
Konstantinos Zekentes ◽  
Katerina Tsagaraki ◽  
Aikaterini Breza ◽  
Nikolaos Frangis
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Periodic Structures ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Nitrogen Ions ◽  
Diffraction Patterns ◽  
Post Implantation

The purpose of the present study is to study the crystal periodicities that appear in 4H- and 6H-SiC material after the implantation with nitrogen and prior to post-implantation annealing. High Resolution X-Ray diffraction (HRXRD) and Transmission Electron Microscopy (TEM) have been employed towards this purpose. Extra peaks at smaller, than the main (00n) peak, diffraction angles in HRXRD scans and extra spots in the electron diffraction patterns have been observed due to the presence of these periodicities. Higher lattice constant periodic structures are apparently formed from the implanted nitrogen ions located at interstitial sites and disappear after the annealing and the resulting positioning of nitrogen atoms in substitutional sites.

Substructure Measurements by Statistical Fluctuations in X-Ray Diffraction Intensity

1965 ◽  
Vol 9 ◽  
pp. 74-90 ◽  
Author(s):  
E. F. Sturcken ◽  
W. E. Gettys ◽  
E. M. Bohn
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Grain Size ◽  
X Ray Diffraction ◽  
Diffraction Intensity ◽  
Laue Diffraction ◽  
X Ray ◽  
Statistical Fluctuations ◽  
Transmission Electron ◽  
Diffraction Patterns

AbstractThe substructures of a bet a-quenched and a recrystallized form of high-purity uranium were measured by a method based on statistical fluctuations in X-ray diffraction intensity. For these measurements, Warren's statistical equation for determining grain size was modified to make the equation applicable to materials with high absorption coefficients or moderate-to-large grain size ( > 20 microns) or both, since many metals fall into this category, and to allow for defocusing of the X-ray beam which occurs as a natural consequence of the experiment.The beta-quenched uranium was found to have numerous subgrains with a range of misorientation angles that was smaller and larger than the limits of the X-ray measurements (Ω = 10−4 to 10−2 steradians). The presence of the large subgrains was corroborated by optical microscopy. The presence of very small subgrains was corroborated by transmission electron microscopy which showed 0.1- to 1-micron subgrains relatively free of dislocations bounded by dense dislocation networks, and by micro Laue diffraction patterns (30-micron beam diameter) which showed partial rings similar to a powder pattern.The recrystallized uranium had no misorientation within the grains greater than 5.5 × 10−3 steradians. In contrast to the beta-quenched case, no subgrains were found either by transmission electron microscopy (TEM) or micro Laue diffraction patterns. The TEM micrographs showed a uniform distribution of dislocation networks. Since no other substructural elements were observed, the dislocations are believed to be the cause of the misorientation within the grains for solid angles of less than 5 × 10−3 steradiflns.These preliminary experiments show that the statistical method may be used in conjunction with transmission electron microscopy and micro Laue diffraction for the study of substructure. The statistical method gives quantitative data on “bulk” specimens that can be given a meaningful interpretation with the aid of the other techniques.

Microstructural evolution of mullites produced from single-phase gels

2007 ◽  
Vol 40 (2) ◽  
pp. 260-276 ◽  
Author(s):  
Marek Andrzej Kojdecki ◽  
Esther Ruiz de Sola ◽  
Francisco Javier Serrano ◽  
Estefanía Delgado-Pinar ◽  
María Mercedes Reventós ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Unit Cell ◽  
Molar Ratio ◽  
Model Parameters ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
Transmission Electron ◽  
Diffraction Patterns

The crystalline microstructure of mullites obtained by heating monophasic gels has been investigated. Gels with alumina to silica molar ratio of 3:2 (as in secondary mullite) and 2:1 (as in primary mullite) were prepared by gelling mixtures of aluminium nitrate and tetraethylorthosilicate. Phase transformations were induced by heating the gel precursors, with different final treatment temperatures between 1173 and 1873 K. The mullites formed as a result of thermal treatment were studied by means of X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The crystalline structure (unit-cell parameters) and microstructure were determined from X-ray diffraction patterns. The formation of mullites of homogeneous chemical composition and with unit-cell parameters depending almost linearly on the treatment temperature was found. Their compositions, expressed as alumina to silica molar ratio, were determined from the unit-cell parameters and were in the range of those characterizing primary and secondary mullites. Mullites processed at lower temperatures were accompanied by small amounts of vitreous phase. The crystalline microstructure of the obtained mullites was interpreted by means of a mathematical model of polycrystalline material, involving prevalent crystallite shape, volume-weighted crystallite size distribution and second-order crystalline lattice strain distribution as model parameters. The model parameters were determined for each sample by modelling its X-ray diffraction pattern and fitting it to a measured pattern. Bimodality of the size distribution was observed and explained as a consequence of two crystallite nucleation and growth processes, which started from small alumina-rich and alumina-poor domains, spontaneously formed in a precursor gel at early stages of heating. Images produced by scanning and transmission electron microscopy agreed well with the characteristics obtained from the analysis of the X-ray diffraction patterns.

scholarly journals Doped Nanoscale NMC333 as Cathode Materials for Li-Ion Batteries

Materials ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 2899 ◽  
Author(s):  
Hashem ◽  
Abdel-Ghany ◽  
Scheuermann ◽  
Indris ◽  
Ehrenberg ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Sol Gel ◽  
Chelating Agent ◽  
Li Ion Batteries ◽  
X Ray Diffraction ◽  
Al Doping ◽  
X Ray ◽  
Transmission Electron ◽  
Li Ion ◽  
Diffraction Patterns

A series of Li(Ni1/3Mn1/3Co1/3)1−xMxO2 (M = Al, Mg, Zn, and Fe, x = 0.06) was prepared via sol-gel method assisted by ethylene diamine tetra acetic acid as a chelating agent. A typical hexagonal α-NaFeO2 structure (R-3m space group) was observed for parent and doped samples as revealed by X-ray diffraction patterns. For all samples, hexagonally shaped nanoparticles were observed by scanning electron microscopy and transmission electron microscopy. The local structure was characterized by infrared, Raman, and Mössbauer spectroscopy and 7Li nuclear magnetic resonance (Li-NMR). Cyclic voltammetry and galvanostatic charge-discharge tests showed that Mg and Al doping improved the electrochemical performance of LiNi1/3Mn1/3Co1/3O2 in terms of specific capacities and cyclability. In addition, while Al doping increases the initial capacity, Mg doping is the best choice as it improves cyclability for reasons discussed in this work.

Synthesis and Formation Mechanism of Hollow Carbon Spheres Containing Fe3N Nanocrystals

2009 ◽  
Vol 79-82 ◽  
pp. 1281-1284 ◽  
Author(s):  
Bo Yang Liu ◽  
De Chang Jia ◽  
Li Hua Dong ◽  
Yan Sheng Yin
Keyword(s):  
Electron Microscopy ◽  
Weight Percent ◽  
Vibrating Sample Magnetometry ◽  
Carbon Spheres ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Structure Morphology ◽  
Hollow Carbon ◽  
Hollow Carbon Spheres

Hollow carbon spheres containing Fe3N nanocrystals (Fe3N/HCSs) are synthesized by ferrocene and ammonium chloride in high pressure argon at 500 °C. The structure, morphology and properties of the products are characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TG) and vibrating sample magnetometry (VSM). The hollow carbon spheres have diameters of 1-10 µm and shell thickness of hundreds of nanometers. The dimensions of the acicular Fe3N nanocrystals have diameters of ca. 100 nm and lengths of 600-800 nm. The weight percent of Fe3N nanocrystals in Fe3N/HCSs is about 37.8%. The saturation magnetization value of the hollow carbon spheres containing Fe3N nanocrystals is 10.61 emu/g.

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