Depositing of Amorphous Ferri-Oxide Nanoparticles on Surfaces of Submicron Aluminum Powder

2013 ◽  
Vol 320 ◽  
pp. 451-455 ◽  
Author(s):  
Yi Wang ◽  
Wei Jiang ◽  
Xiao Lan Song ◽  
Guo Dong Deng ◽  
Feng Sheng Li
Keyword(s):  
Sol Gel ◽  
Sem Analysis ◽  
Mass Ratio ◽  
Weak Base ◽  
Aluminum Particles ◽  
Xrd Pattern ◽  
The Core ◽  
Peak Point ◽  
Core Shell Structure ◽  
Gel Processing

Nanoparticles with about 20nm diameter were densely coated on the surface of submicron Al via a sol-gel processing in ethanol, wherein 1,2-epoxypropane acted as a weak base to consume proton in solution. After the medium gelled, uniform network formed and aluminum particles imbedded in it. The core-shell structure and the nanoparticles were observed in SEM analysis. The EDS spectrum and the XRD pattern revealed that the cores consisted of amorphous ferri-oxide of which the mass ratio is closed to that of crystal Fe2O3. Thermal analysis was performed and the results indicated that the DSC peak point of ferri-oxide/Al nanocomposite showed 53 °C lower than that of [ferri-oxide+A simple mixture.

scholarly journals Synthesis Of SiC/Cu Composite Powders From Polycarbosilane And Cupric Nitrate Trihydrate

2015 ◽  
Vol 60 (2) ◽  
pp. 1261-1263 ◽  
Author(s):  
S.-R. Bang ◽  
D.-M. Yim ◽  
D.-H. Riu ◽  
S.-T. Oh
Keyword(s):  
Hydrogen Reduction ◽  
Sem Analysis ◽  
Composite Powders ◽  
Nitrate Hydrate ◽  
Cupric Nitrate ◽  
The Core ◽  
Nitrate Trihydrate ◽  
Barrier Coating ◽  
Core Shell Structure ◽  
Al Coating

Abstract SiC/Cu composite powders with the barrier coating of SiC-Al onto SiC powders were synthesized from Al-containing polycarbosilane precursor and Cu-nitrate hydrate. Curing at 200°C and high temperature pyrolysis at 1600°C was used to achieve the crystallization of precursor, forming the SiC-Al coating on the surface of SiC powders. A core-shell structure with the core of SiC and the shell of Cu was constructed by calcination and hydrogen-reduction of Cu nitrate hydrate. XRD and SEM analysis revealed that the β-SiC and 4H-SiC phases were formed on the surface of the initial α-SiC powders. Also, it was observed by EDX mapping that core powders of SiC were homogeneously surrounded with the fine Cu particles on their surface.

Aluminum Pigments Encapsulated by MTES and TEOS for Corrosion Inhibition and their Characterizations

2014 ◽  
Vol 541-542 ◽  
pp. 7-11
Author(s):  
Pi Hui Pi ◽  
Chao Liu ◽  
Xiu Fang Wen ◽  
Shou Ping Xu ◽  
Jiang Cheng
Keyword(s):  
Corrosion Inhibition ◽  
Hybrid Film ◽  
Sol Gel ◽  
Sem Analysis ◽  
Aluminum Particles ◽  
Corrosive Media ◽  
Acid Media ◽  
Excellent Corrosion Resistance ◽  
Gel Layer ◽  
Inhibition Performance

Aluminum pigments were encapsulated by hydrolysis and condensation of tetraethoxysilane (TEOS) and methyltriethoxysilane (MTES). The influences of solvents and ratio of MTES/TEOS on corrosion inhibition performance were studied. The FTIR, XPS and SEM analysis showed that both TEOS and MTES hydrolyzed and condensed at the same time to form a compact and thin sol-gel layer on the surface of aluminum pigments. Aluminum pigments encapsulated by MTES and TEOS, which can hardly generate H2 in acid media of pH=1 within 12h, show greatly excellent corrosion resistance than that only by TEOS or by MTES, due to the formation of a compact and thin hybrid film to protect aluminum particles from corrosive media.

Synthesis and Photoluminescence Properties of Monodisperse Spherical SiO2@Lu2O3: Eu3+ Particles with Core-Shell Structure

2014 ◽  
Vol 1004-1005 ◽  
pp. 389-392
Author(s):  
Huan Wang
Keyword(s):  
Smooth Surface ◽  
Sol Gel ◽  
Spherical Shape ◽  
Core Shell ◽  
Narrow Size Distribution ◽  
Photoluminescence Properties ◽  
The Core ◽  
Sol Gel Process ◽  
Core Shell Structure ◽  
Shell Particles

Spherical submicron SiO2 particles have been coated with luminescent Lu2O3: Eu3+ layers by a Pechini sol-gel process, resulting in the formation of SiO2@Lu2O3: Eu3+ core-shell particles(300, 500 nm). The obtained core–shell phosphors have perfect spherical shape with narrow size distribution, smooth surface and non-agglomeration. The thickness of shells could be easily controlled by changing the number of deposition cycles (50 nm for four deposition cycles). Under the excitation of ultraviolet, the Eu3+ ion mainly shows its characteristic emissions in the core-shell particles from Lu2O3: Eu3+) shells. The PL intensity of Eu3+ increases with the number of coating cycles.

scholarly journals Polymer assisted colloidal nanocrystal framework synthesis: sol-gel approach

2021 ◽  
Author(s):  
Buzuayehu Abebe
Keyword(s):  
Image Analysis ◽  
Metal Oxides ◽  
Vinyl Alcohol ◽  
Sol Gel ◽  
Compositional Analysis ◽  
Sem Analysis ◽  
Poly Vinyl Alcohol ◽  
Hrtem Image ◽  
Xrd Pattern ◽  
Hsab Theory

Abstract The porous colloidal nanocrystal framework material was synthesized by sol-gel assembly followed by a self-propagation procedure. The characteristics of the synthesized nanocrystal were confirmed by advanced instruments. From the DTG analysis, the poly (vinyl alcohol) was completely degraded at 400 °C. The XRD pattern and TEM image confirmed the nanoscale crystallite size of the material. BET and SEM analysis showed the mesoporous type pore size distribution. The predictable compositional analysis was confirmed from EDX, SAED, and XPS compositional analysis. Using the HSAB theory and HRTEM image analysis the formation of local heterojunction between metal oxides was approved.

Preparation of GDC Nanopowders and GDC/YSZ Core-Shell Nanocomposites

2010 ◽  
Vol 434-435 ◽  
pp. 717-718
Author(s):  
Zuo Cai Huang ◽  
Bin Li ◽  
Wei Liu ◽  
Wei Pan
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Sol Gel ◽  
Precipitation Method ◽  
Core Shell ◽  
The Core ◽  
Transmission Electron ◽  
Core Shell Structure ◽  
Co Precipitation

Nanocrystalline GDC as small as 5 nm was successfully synthesized via the co-precipitation method. GDC/YSZ core-shell nanocrystals, which were GDC nanocrystals overcoated by a thin YSZ layer, was successfully synthesized by the addition of GDC nanocrystals in the YSZ source solution using sol-gel method. The core-shell structure was supported by its high-resolution transmission electron microscopy results and the composition was investigated by EDX method.

scholarly journals A SERS Study of Charge Transfer Process in Au Nanorod–MBA@Cu2O Assemblies: Effect of Length to Diameter Ratio of Au Nanorods

Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 867
Author(s):  
Lin Guo ◽  
Zhu Mao ◽  
Sila Jin ◽  
Lin Zhu ◽  
Junqi Zhao ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Shell Structure ◽  
Shell Structures ◽  
Core Shell ◽  
Absorption Bands ◽  
Au Nanorods ◽  
The Core ◽  
Band Position ◽  
Surface Enhanced Raman ◽  
Core Shell Structure

Surface-enhanced Raman scattering (SERS) is a powerful tool in charge transfer (CT) process research. By analyzing the relative intensity of the characteristic bands in the bridging molecules, one can obtain detailed information about the CT between two materials. Herein, we synthesized a series of Au nanorods (NRs) with different length-to-diameter ratios (L/Ds) and used these Au NRs to prepare a series of core–shell structures with the same Cu2O thicknesses to form Au NR–4-mercaptobenzoic acid (MBA)@Cu2O core–shell structures. Surface plasmon resonance (SPR) absorption bands were adjusted by tuning the L/Ds of Au NR cores in these assemblies. SERS spectra of the core-shell structure were obtained under 633 and 785 nm laser excitations, and on the basis of the differences in the relative band strengths of these SERS spectra detected with the as-synthesized assemblies, we calculated the CT degree of the core–shell structure. We explored whether the Cu2O conduction band and valence band position and the SPR absorption band position together affect the CT process in the core–shell structure. In this work, we found that the specific surface area of the Au NRs could influence the CT process in Au NR–MBA@Cu2O core–shell structures, which has rarely been discussed before.

Construction of MOFs-Shell Porous Materials and Performance Study in Selective Adsorption and Separation of Benzene Pollutants

2021 ◽  
Author(s):  
Yu Qiao ◽  
Na Lv ◽  
Dong Li ◽  
Hongji Li ◽  
Xiangxin Xue ◽  
...  
Keyword(s):  
Porous Materials ◽  
Shell Structure ◽  
Selective Adsorption ◽  
Core Shell ◽  
Architecture Design ◽  
Performance Study ◽  
The Core ◽  
Core Shell Structure ◽  
And Performance ◽  
Sacrificial Agent

Metastable Cu2O is an attractive material for the architecture design of integrated nanomaterials. In this context, Cu2O was used as the sacrificial agent to form the core-shell structure of Cu2O@HKUST-1...

Synthesis and characterization of BaMgAl10O17:Eu phosphors derived by sol–gel processing

2002 ◽  
Vol 126 (2) ◽  
pp. 161-165 ◽  
Author(s):  
Junying Zhang ◽  
Zhongtai Zhang ◽  
Zilong Tang ◽  
Zishan Zheng ◽  
Yuanhua Lin
Keyword(s):  
Sol Gel ◽  
Synthesis And Characterization ◽  
Gel Processing
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