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.

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.

Effect of CNTs on Mechanical Properties of SiCp/Cu Composites

2014 ◽  
Vol 602-603 ◽  
pp. 590-593
Author(s):  
Chen Yang Wang ◽  
Bing Bing Fan ◽  
Bing Sun ◽  
Bin Bin Wang ◽  
Wen Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Shell Structure ◽  
Volume Fraction ◽  
Composite Particles ◽  
Core Shell ◽  
Maximum Hardness ◽  
Composite Powders ◽  
The Core ◽  
Core Shell Structure

SiCp/Cu composites were prepared by vacuum hot-pressing at 770°C for 1.5 h under the pressure of 30MPa. The composites were enhanced by CNTs with different volume fractions from 0 vol. % to 4 vol. %. Three-step approach wrapping process was introduced to prepare composite powders. XRD and SEM techniques were used to characterize the samples. It is found that the core-shell structure composed of SiC core and Cu shell was formed in the composite particles. Optimized volume fraction of CNTs is 1 vol. %. Minimum Porosity and maximum Hardness is about 0.84% and 2.31GPa, respectively. But maximum Flexural strength was measured as 248MPa for samples containing 2 vol. % CNTs. Flexural strength was improved by the bridge effect caused by the increased CNTs.

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...

Preparation of polyacrylamide microspheres with core–shell structure via surface-initiated atom transfer radical polymerization

RSC Advances ◽  
2016 ◽  
Vol 6 (94) ◽  
pp. 91463-91467 ◽  
Author(s):  
Peng Zhang ◽  
Shixun Bai ◽  
Shilan Chen ◽  
Dandan Li ◽  
Zhenfu Jia ◽  
...  
Keyword(s):  
Atom Transfer Radical Polymerization ◽  
Radical Polymerization ◽  
Shell Structure ◽  
Core Shell ◽  
Atom Transfer ◽  
The Core ◽  
Core Shell Structure

Well defined core–shell microspheres were prepared by surface-initiated atom transfer radical polymerization with pre-crosslinked polyacrylamide as the core and non-crosslinked polyacrylamide as the shell.

Core–shell stability of nanoparticles plays an important role for overcoming the intestinal mucus and epithelium barrier

2016 ◽  
Vol 4 (35) ◽  
pp. 5831-5841 ◽  
Author(s):  
Min Liu ◽  
Lei Wu ◽  
Xi Zhu ◽  
Wei Shan ◽  
Lian Li ◽  
...  
Keyword(s):  
Shell Structure ◽  
Core Shell ◽  
The Core ◽  
Shell Stability ◽  
Intestinal Mucus ◽  
Core Shell Structure ◽  
The Stability

The stability of the core–shell structure plays an important role in the nanoparticles ability to overcome both the mucus and epithelium absorption barrier.

Characterization of Fe3O4@CS@NMDP magnetic nanoparticles with core–shell structure prepared by chemical cross-linking method

2017 ◽  
Vol 10 (05) ◽  
pp. 1750056 ◽  
Author(s):  
Huiping Shao ◽  
Jiangcong Qi ◽  
Tao Lin ◽  
Yuling Zhou ◽  
Fucheng Yu
Keyword(s):  
Magnetic Nanoparticles ◽  
Shell Structure ◽  
High Performance ◽  
Cross Linking ◽  
Composite Particles ◽  
Core Shell ◽  
The Core ◽  
Targeting Delivery ◽  
Core Shell Structure ◽  
Chemical Cross Linking

The core–shell structure composite magnetic nanoparticles (NPs), Fe3O4@chitosan@nimodipine (Fe3O4@CS@NMDP), were successfully synthesized by a chemical cross-linking method in this paper. NMDP is widely used for cardiovascular and cerebrovascular disease prevention and treatment, while CS is of biocompatibility. The composite particles were characterized by an X-ray diffractometer (XRD), a Fourier transform infrared spectroscopy (FT-IR), a transmission electron microscopy (TEM), a vibrating sample magnetometers (VSM) and a high performance liquid chromatography (HPLC). The results show that the size of the core–shell structure composite particles is ranging from 12[Formula: see text]nm to 20[Formula: see text]nm and the coating thickness of NMDP is about 2[Formula: see text]nm. The saturation magnetization of core–shell composite NPs is 46.7[Formula: see text]emu/g, which indicates a good potential application for treating cancer by magnetic target delivery. The release percentage of the NMDP can reach 57.6% in a short time of 20[Formula: see text]min in the PBS, and to 100% in a time of 60[Formula: see text]min, which indicates the availability of Fe3O4@CS@NMDP composite NPs for targeting delivery treatment.

Influence of Lysozyme on the Biomimetic Growth of Silica Tubes in Porous Membranes

2007 ◽  
Vol 1008 ◽  
Author(s):  
Clémentine Gautier ◽  
Rémi Courson ◽  
Pascal Jean Lopez ◽  
Jacques Livage ◽  
Thibaud Coradin
Keyword(s):  
Porous Membranes ◽  
Shell Formation ◽  
Core Particle ◽  
Biomimetic Models ◽  
Membrane Pores ◽  
The Core ◽  
Core Shell Structure ◽  
Poly Carbonate ◽  
Tube Shell

AbstractPore channels of poly-carbonate membranes were recently used as biomimetic models to study the effect of confinement on silicate condensation, leading to the formation of silica tubes exhibiting a core-shell structure. In this work, we pre-immobilized lysozyme on the membrane pores, inducing the modification of the tube shell formation process, and variation in core particle size. These data strengthen previous assumptions on the role of interfacial interactions on the growth of the tube shell and indicate that such interactions also influence the core particle formation. Such approach therefore seems suitable to mimic the formation of silica/protein multilayers as found in several biomineralizing organisms

The use of galvanic displacement in synthesizing Pt(Cu) catalysts with the core-shell structure

2010 ◽  
Vol 46 (10) ◽  
pp. 1189-1197 ◽  
Author(s):  
B. I. Podlovchenko ◽  
T. D. Gladysheva ◽  
A. Yu. Filatov ◽  
L. V. Yashina
Keyword(s):  
Shell Structure ◽  
Core Shell ◽  
Galvanic Displacement ◽  
The Core ◽  
Cu Catalysts ◽  
Core Shell Structure

scholarly journals Synthesis and Control of the Shell Thickness of Polyaniline and Polypyrrole Half Hollow Spheres Using the Polystyrene Cores

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Su-Ryeon Yun ◽  
Gyeong-Ok Kim ◽  
Chan Woo Lee ◽  
Nam-Ju Jo ◽  
Yongku Kang ◽  
...  
Keyword(s):  
Shell Thickness ◽  
Hollow Spheres ◽  
Core Shell ◽  
Chemical Structures ◽  
The Core ◽  
Vis Spectroscopy ◽  
Ft Ir ◽  
Core Shell Structure ◽  
And Control ◽  
Ft Ir Spectroscopy

Polyaniline (Pani) and polypyrrole (Ppy) half hollow spheres with different shell thicknesses were successfully synthesized by three steps process using polystyrene (PS) as the core. The PS core was synthesized by emulsion polymerization. Aniline and pyrrole monomers were polymerized on the surface of the PS core. The shells of Pani and Ppy were fabricated by adding different amounts of aniline and pyrrole monomers. PS cores were dissolved and removed from the core shell structure by solvent extraction. The thicknesses of the Pani and Ppy half hollow spheres were observed by FE-SEM and FE-TEM. The chemical structures of the Pani and Ppy half hollow spheres were characterized by FT-IR spectroscopy and UV-Vis spectroscopy. The shell thicknesses of the Pani half hollow spheres were 30.2, 38.0, 42.2, 48.2, and 52.4 nm, while the shell thicknesses of the Ppy half hollow spheres were 16.0, 22.0, 27.0, and 34.0 nm. The shell thicknesses of Pani and Ppy half hollow spheres linearly increased as the amount of the monomer increased. Therefore, the shell thickness of the Pani and Ppy half hollow spheres can be controlled in these ranges.

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