Aerosol-gel-derived Microcrystalline Hydroxyapatite Coatings

2002 ◽  
Vol 17 (6) ◽  
pp. 1482-1489 ◽  
Author(s):  
M. Manso ◽  
J. M. Martínez-Duart ◽  
M. Langlet ◽  
C. Jiménez ◽  
P. Herrero ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Calcium Nitrate ◽  
X Ray ◽  
Si Substrates ◽  
Hydroxyapatite Coatings ◽  
Transmission Electron ◽  
Phosphate Phase ◽  
Different Temperatures ◽  
Composition Structure ◽  
Highly Porous

Highly porous microcrystalline hydroxyapatite (HAP) coatings have been prepared from calcium nitrate and phosphoric acid based sols by the aerosol-gel process. The coatings were studied after sintering at different temperatures with the use of Fourier transform infrared spectroscopy, x-ray diffraction, energy disperse x-ray microanalysis, scanning electron microscopy, and transmission electron microscopy. The composition, structure, and morphology of the coatings sintered at 650 °C fit fairly well highly porous HAP. These coatings were reproduced onto TiO2/Si substrates and studied by Rutherford backscattering. It is shown that even after chemical etching, an adherent calcium phosphate phase remains attached to the TiO2/Si substrate.

Direct Deposition Reactions Between Nickel and Silicon Substrates

1993 ◽  
Vol 311 ◽  
Author(s):  
Lin Zhang ◽  
Douglas G. Ivey
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Silicon Substrates ◽  
Silicide Formation ◽  
Cross Sectional ◽  
Deposition Rates ◽  
Plan View ◽  
X Ray ◽  
Si Substrates ◽  
Transmission Electron

ABSTRACTSilicide formation through deposition of Ni onto hot Si substrates has been investigated. Ni was deposited onto <100> oriented Si wafers, which were heated up to 300°C, by e-beam evaporation under a vacuum of <2x10-6 Torr. The deposition rates were varied from 0.1 nm/s to 6 nm/s. The samples were then examined by both cross sectional and plan view transmission electron microscopy (TEM), energy dispersive x-ray spectroscopy and electron diffraction. The experimental results are discussed in terms of a new kinetic model.

Preparation and Property of Al87Ce3Ni8.5Mn1.5 Nanophase Amorphous Composites

2011 ◽  
Vol 412 ◽  
pp. 263-266
Author(s):  
Hong Wei Zhang ◽  
Li Li Zhang ◽  
Feng Rui Zhai ◽  
Jia Jin Tian ◽  
Can Bang Zhang
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Single Phase ◽  
Volume Fraction ◽  
Material Structure ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Transmission Electron ◽  
Different Temperatures

The higher mechanical strength of Al87Ce3Ni8.5Mn1.5 nanophase amorphous composites has been obtained with two methods. The first nanophase amorphous composites are directly produced by the single roller spin quenching technology. The method taken for the second nanophase amorphous composites is at first to obtain amorphous single-phase alloy, followed by annealed at different temperatures .The formative condition, the microstructure, the particle size, the volume fraction of α-Al phase and microhardness of nanophase amorphous composites etc have been investigated and compared by X-ray diffraction (XRD) and transmission electron microscopy (TEM) and differential scanning calorimetry (DSC). The microstructure of composites produced by the second method is higher than the former, the fabricated material structure of the system is more uniform and the process is easier to control.

A new high-temperature inorganic–organic proton conductor: lanthanum sulfophenyl phosphate

2016 ◽  
Vol 70 (3) ◽  
Author(s):  
Ming-Feng Song ◽  
Zhong-Fang Li ◽  
Guo-Hong Liu ◽  
Su-Wen Wang ◽  
Xiao-Yan Yin ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Layered Structure ◽  
Proton Conductor ◽  
X Ray Diffraction ◽  
X Ray ◽  
Good Thermal Stability ◽  
Transmission Electron ◽  
Good Crystallinity ◽  
Different Temperatures ◽  
Thermal Stability Of

AbstractLanthanum sulfophenyl phosphate (LaSPP) was synthesized by m-sulfophenyl phosphonic acid and lanthanum nitrate. UV-Vis spectrophotometry and Fourier-transform infrared spectroscopy indicate that the desired product was obtained and its elementary composition and typical layered structure were determined by energy dispersive X-ray spectroscopy and scanning electron microscopy. Transmission electron microscopy (TEM) proved its typical layered structure and X-ray diffraction spectroscopy indicated its good crystallinity and the interlayer distance of about 15.67 Å , which matches the value obtained by TEM (2.0 nm). Thermogravimetry and differential thermal analysis revealed good thermal stability of LaSPP. Proton conductivity of LaSPP was measured at different temperatures and relative humidities (RH), reaching values of 0.123 S cm

Hydrothermal Synthesis of Visible Light Active SnO2-SnS2 Nanocomposite Photocatalyst for the Reduction of Cr(VI) in Water

2013 ◽  
Vol 709 ◽  
pp. 7-10
Author(s):  
Jing Li ◽  
Xi Hua Du ◽  
Wei Min Dai ◽  
Yong Cai Zhang
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Sno2 Nanoparticles ◽  
High Photocatalytic Activity ◽  
X Ray ◽  
Transmission Electron ◽  
Visible Light Active ◽  
Composition Structure

A low temperature (130 °C) hydrothermal method was proposed for the synthesis of SnO2-SnS2 nanocomposite. The composition, structure and optical property of the as-synthesized SnO2-SnS2 nanocomposite were characterized by X-ray diffraction, energy dispersive X-ray spectroscopy, transmission electron microscopy, high-resolution transmission electron microscopy and UV-vis diffuse reflectance spectra, and its photocatalytic activity was tested by the reduction of Cr(VI) in water under visible light (λ > 420 nm) irradiation. It was found that the as-synthesized SnO2-SnS2 nanocomposite exhibited high photocatalytic activity in the reduction of Cr(VI) in water under visible light (λ > 420 nm) irradiation, whereas SnO2 nanoparticles displayed no photocatalytic activity in the reduction of Cr(VI) in water under visible light (λ > 420 nm) irradiation.

scholarly journals Biochar-Supported FeS/Fe3O4 Composite for Catalyzed Fenton-Type Degradation of Ciprofloxacin

Catalysts ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1062 ◽  
Author(s):  
Yue Wang ◽  
Xiaoxiao Zhu ◽  
Dongqing Feng ◽  
Anthony K. Hodge ◽  
Liujiang Hu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Iron Sulfide ◽  
Magnetic Composite ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Magnetite Fe3o4 ◽  
Different Temperatures ◽  
Cost Efficient

The Fenton-type oxidation catalyzed by iron minerals is a cost-efficient and environment-friendly technology for the degradation of organic pollutants in water, but their catalytic activity needs to be enhanced. In this work, a novel biochar-supported composite containing both iron sulfide and iron oxide was prepared, and used for catalytic degradation of the antibiotic ciprofloxacin through Fenton-type reactions. Dispersion of FeS/Fe3O4 nanoparticles was observed with scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS) and transmission electron microscopy (TEM). Formation of ferrous sulfide (FeS) and magnetite (Fe3O4) in the composite was validated by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Ciprofloxacin (initial concentration = 20 mg/L) was completely degraded within 45 min in the system catalyzed by this biochar-supported magnetic composite at a dosage of 1.0 g/L. Hydroxyl radicals (·OH) were proved to be the major reactive species contributing to the degradation reaction. The biochar increased the production of ·OH, but decreased the consumption of H2O2, and helped transform Fe3+ into Fe2+, according to the comparison studies using the unsupported FeS/Fe3O4 as the catalyst. All the three biochars prepared by pyrolysis at different temperatures (400, 500 and 600 °C) were capable for enhancing the reactivity of the iron compound catalyst.

Upcycling of Polystyrene Waste Plastics to High Value Carbon by Thermal Decomposition

2021 ◽  
Vol 897 ◽  
pp. 103-108
Author(s):  
Kenneth Mensah ◽  
Hatem Mahmoud ◽  
Manabu Fujii ◽  
Hassan Shokry
Keyword(s):  
Electron Microscopy ◽  
Thermal Decomposition ◽  
Waste Plastics ◽  
X Ray Diffraction ◽  
X Ray ◽  
Environmental Threats ◽  
Transmission Electron ◽  
Different Temperatures ◽  
Polystyrene Waste ◽  
Synthesized Materials

Globally, the adverse environmental impact of waste plastics is of increasing concern. Most plastics are naturally non-degradable, thus imposes serious environmental threats, especially, to marine life. Upcycling such waste into valuable contents is an effective approach to managing waste plastics. In this study, graphene is synthesized from waste polystyrene (PS) by thermal decomposition at different temperatures (500, 600, 700, 800, 900 and 1000 °C) for two hours reaction time in a stainless steel autoclave. The synthesized materials are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Energy-disperse X-ray analysis (EDS) and surface area by using Brunauer–Emmett–Teller (BET). The yield of the product materials was investigated and optimized against the temperature. The synthesized graphene is considered a promising material for many applications, especially in environmental applications.

Influence of the Precipitation Temperature on Properties of Nanohydroxyapatite Powder for the Fabrication of Highly Porous Bone Scaffolds

2013 ◽  
Vol 587 ◽  
pp. 27-32 ◽  
Author(s):  
Cristian Parisi ◽  
Francesca Gervaso ◽  
Francesca Scalera ◽  
Sanosh Kunjalukkal Padmanabhan ◽  
Concetta Nobile ◽  
...  
Keyword(s):  
Calcium Nitrate ◽  
Bone Substitutes ◽  
Porous Scaffolds ◽  
Calcium Nitrate Tetrahydrate ◽  
High Porosity ◽  
Precipitation Temperature ◽  
Transmission Electron ◽  
Nitrate Tetrahydrate ◽  
Different Temperatures ◽  
Highly Porous

The aim of the present work is to study the influence of the precipitation temperature in the synthesis of nanohydroxyapatite (n-HAp) on the properties of the resulting n-HAp powder for the fabrication of highly porous scaffolds for bone tissue engineering. The n-HAp powder was obtained by a wet precipitation technique starting from calcium nitrate tetrahydrate (Ca (NO3)2*4H2O) and phosphoric acid (H3PO4) at different temperatures: 10°C, 37°C and 50°C. Highly porous scaffolds were fabricated using the three different powders by the sponge replica method and sintering at 1300°C. Combined X-ray diffraction (XRD) and transmission electron microscopy (TEM) analyses on powders indicated that on increasing the precipitation temperature the formation of pure n-HAp is accelerated, without significant changes in particles morphology and size. Scaffolds characterized by high porosity (89%) and good compressive strength (0.53 MPa for n-HAp prepared at 37°C) were obtained. XRD analyses on sintered n-HAp confirmed the thermal stability of the material. Therefore, the as-synthesized n-HAp powder can be successfully used for the fabrication of highly porous scaffolds as bone substitutes.

scholarly journals Thermodynamic Study of Adsorption of Tamoxifen Drug on Activated Nano-Coal Particles prepared from Stem of Eucalyptus and its Diagnosis by different Techniques

2020 ◽  
Vol 10 (03) ◽  
pp. 328-331
Author(s):  
Ahmed Taha Yaseen ◽  
Liqa’a Hussein Alwan
Keyword(s):  
Electron Microscopy ◽  
Adsorption Process ◽  
Heat Emission ◽  
Adsorption Efficiency ◽  
Emission Process ◽  
X Ray ◽  
Transmission Electron ◽  
Coal Particles ◽  
Different Temperatures ◽  
Degree Equation

The research included preparing nano-activated charcoal from the stem of the eucalyptus trees. The prepared nano-coal particles were diagnosed using various techniques, such as, transmission electron microscopy (TEM), and energy-dispersive X-ray (EDX) technology. The research included a spectroscopic study of the adsorption of tamoxifen on the prepared nano-coal, and the results showed that the appropriate concentration is 2.5 × 10-5 molar, with an appropriate weight of the adsorbent material which is 0.4-gram, the time of equilibrium is 40 minutes, and the percentage of adsorption efficiency increases with passing time, the adsorption process is dependent to a second-degree equation, according to the correlation coefficient (R2), which gave the value of 0.9999. Thermodynamic functions were calculated for the adsorption process at different temperatures (17.5, 27.5, 37.5, and 47.5ºC), and it was found that the adsorption process is a heat emission process (ΔH negative), the adsorption is physical because it is less than 40 kJ/mol, and the free energy is negative (ΔG), and entropy adsorption was negative (ΔS), meaning less random.

Synthesis of SiOx Nanowires through the Thermal Heating of Au-Coated Si Substrates

2007 ◽  
Vol 119 ◽  
pp. 79-82
Author(s):  
Hyoun Woo Kim ◽  
S.H. Shim ◽  
Jong Woo Lee
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Thermal Heating ◽  
X Ray Diffraction ◽  
X Ray ◽  
Si Substrates ◽  
Transmission Electron ◽  
Amorphous Structures ◽  
Scanning Electron

We have demonstrated the growth of SiOx nanowires by the simple heating of the Au-coated Si substrates. We used X-ray diffraction, scanning electron microscopy, energy dispersive x-ray spectroscopy, and transmission electron microscopy to characterize the samples. The as-synthesized SiOx nanowires had amorphous structures with diameters in the range of 10-70 nm. We have discussed the possible growth mechanism.

AlN Wafers Fabricated by Hydride Vapor Phase Epitaxy

1999 ◽  
Vol 595 ◽  
Author(s):  
Andrey Nikolaev ◽  
Irina Nikitina ◽  
Andrey Zubrilov ◽  
Marina Mynbaeva ◽  
Yuriy Melnik ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Vapor Phase ◽  
Vapor Phase Epitaxy ◽  
Hydride Vapor Phase Epitaxy ◽  
X Ray Diffraction ◽  
Free Standing ◽  
X Ray ◽  
Si Substrates ◽  
Transmission Electron ◽  
Thick Layers

AbstractWe report on AlN wafers fabricated by hydride vapor phase epitaxy (HVPE). AlN thick layers were grown on Si substrates by HVPE. Growth rate was up to 60 microns per hour. After the growth of AlN layers, initial substrates were removed resulting in free-standing AlN wafers. The maximum thickness of AlN layer was about 1 mm. AlN free-standing single crystal wafers with a thickness ranging from 0.05 to 0.8 mm were studied by x-ray diffraction, transmission electron microscopy, optical absorption, and cathodoluminescence.

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