Fabrication and Properties of Core-Shell Type SiC/SiO2 Nanowires Through Low-Cost Production Technique

2010 ◽  
pp. 51-62 ◽  
Author(s):  
Wasana Khongwong ◽  
Katsumi Yoshida ◽  
Toyohiko Yano
Keyword(s):  
Low Cost ◽  
Core Shell ◽  
Production Technique ◽  
Shell Type ◽  
Sio2 Nanowires

scholarly journals Facile Synthesis of Carboxymethyl Cellulose Coated Core/Shell SiO2@Cu Nanoparticles and Their Antifungal Activity against Phytophthora capsici

Polymers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 888
Author(s):  
Nguyen Thi Thanh Hai ◽  
Nguyen Duc Cuong ◽  
Nguyen Tran Quyen ◽  
Nguyen Quoc Hien ◽  
Tran Thi Dieu Hien ◽  
...  
Keyword(s):  
Antifungal Activity ◽  
Carboxymethyl Cellulose ◽  
Chemical Reduction ◽  
Low Cost ◽  
Phytophthora Capsici ◽  
Reduction Process ◽  
Spherical Shape ◽  
Core Shell ◽  
Cu Nanoparticles ◽  
Average Size

Cu nanoparticles are a potential material for creating novel alternative antimicrobial products due to their unique antibacterial/antifungal properties, stability, dispersion, low cost and abundance as well as being economical and ecofriendly. In this work, carboxymethyl cellulose coated core/shell SiO2@Cu nanoparticles (NPs) were synthesized by a simple and effective chemical reduction process. The initial SiO2 NPs, which were prepared from rice husk ash, were coated by a copper ultrathin film using hydrazine and carboxymethyl cellulose (CMC) as reducing agent and stable agent, respectively. The core/shell SiO2@Cu nanoparticles with an average size of ~19 nm were surrounded by CMC. The results indicated that the SiO2@Cu@CMC suspension was a homogenous morphology with a spherical shape, regular dispersion and good stability. Furthermore, the multicomponent SiO2@Cu@CMC NPs showed good antifungal activity against Phytophthora capsici (P. capsici). The novel Cu NPs-based multicomponent suspension is a key compound in the development of new fungicides for the control of the Phytophthora disease.

scholarly journals Fabrication of Hollow Core-Shell Type Si/C Nanocomposites by a Simple Process

2017 ◽  
Vol 15 (0) ◽  
pp. 69-73 ◽  
Author(s):  
Kei Wakabayashi ◽  
Daichi Yamaura ◽  
Kazuki Ito ◽  
Naoya Kameda ◽  
Toshio Ogino
Keyword(s):  
Core Shell ◽  
Hollow Core ◽  
Simple Process ◽  
Shell Type

scholarly journals CdSe/ZnS Core-Shell-Type Quantum Dot Nanoparticles Disrupt the Cellular Homeostasis in Cellular Blood–Brain Barrier Models

2021 ◽  
Vol 22 (3) ◽  
pp. 1068
Author(s):  
Katarzyna Dominika Kania ◽  
Waldemar Wagner ◽  
Łukasz Pułaski
Keyword(s):  
Gene Expression ◽  
Quantum Dot ◽  
Blood Brain Barrier ◽  
Protein Gene ◽  
Brain Barrier ◽  
Core Shell ◽  
Cellular Homeostasis ◽  
Blood Brain ◽  
Shell Type ◽  
The Impact

Two immortalized brain microvascular endothelial cell lines (hCMEC/D3 and RBE4, of human and rat origin, respectively) were applied as an in vitro model of cellular elements of the blood–brain barrier in a nanotoxicological study. We evaluated the impact of CdSe/ZnS core-shell-type quantum dot nanoparticles on cellular homeostasis, using gold nanoparticles as a largely bioorthogonal control. While the investigated nanoparticles had surprisingly negligible acute cytotoxicity in the evaluated models, a multi-faceted study of barrier-related phenotypes and cell condition revealed a complex pattern of homeostasis disruption. Interestingly, some features of the paracellular barrier phenotype (transendothelial electrical resistance, tight junction protein gene expression) were improved by exposure to nanoparticles in a potential hormetic mechanism. However, mitochondrial potential and antioxidant defences largely collapsed under these conditions, paralleled by a strong pro-apoptotic shift in a significant proportion of cells (evidenced by apoptotic protein gene expression, chromosomal DNA fragmentation, and membrane phosphatidylserine exposure). Taken together, our results suggest a reactive oxygen species-mediated cellular mechanism of blood–brain barrier damage by quantum dots, which may be toxicologically significant in the face of increasing human exposure to this type of nanoparticles, both intended (in medical applications) and more often unintended (from consumer goods-derived environmental pollution).

scholarly journals Bimetallic Core–Shell Nanoparticles of Gold and Silver via Bioinspired Polydopamine Layer as Surface-Enhanced Raman Spectroscopy (SERS) Platform

Nanomaterials ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 688 ◽  
Author(s):  
Asli Yilmaz ◽  
Mehmet Yilmaz
Keyword(s):  
Raman Spectroscopy ◽  
Low Cost ◽  
Silver Ions ◽  
Surface Enhanced Raman Spectroscopy ◽  
Core Shell ◽  
Silver Deposition ◽  
Shell Nanoparticles ◽  
Surface Enhanced ◽  
Surface Enhanced Raman ◽  
Core Shell Nanoparticles

Despite numerous attempts to fabricate the core–shell nanoparticles, novel, simple, and low-cost approaches are still required to produce these efficient nanosystems. In this study, we propose the synthesis of bimetallic core–shell nanoparticles of gold (AuNP) and silver (AgNP) nanostructures via a bioinspired polydopamine (PDOP) layer and their employment as a surface-enhanced Raman spectroscopy (SERS) platform. Herein, the PDOP layer was used as an interface between nanostructures as well as stabilizing and reducing agents for the deposition of silver ions onto the AuNPs. UV-vis absorption spectra and electron microscope images confirmed the deposition of the silver ions and the formation of core–shell nanoparticles. SERS activity tests indicated that both the PDOP thickness and silver deposition time are the dominant parameters that determine the SERS performances of the proposed core–shell system. In comparison to bare AuNPs, more than three times higher SERS signal intensity was obtained with an enhancement factor of 3.5 × 105.

scholarly journals Effect of Core-Shell Ag@TiO2Volume Ratio on Characteristics of TiO2-Based DSSCs

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Ho Chang ◽  
Chih-Hao Chen ◽  
Mu-Jung Kao ◽  
Hsin-Han Hsiao
Keyword(s):  
Conversion Efficiency ◽  
Short Circuit ◽  
Dye Sensitized Solar Cells ◽  
Open Circuit ◽  
Photoelectric Conversion Efficiency ◽  
Core Shell ◽  
Photoelectric Conversion ◽  
Shell Type ◽  
Degussa P25 ◽  
Triton X

This paper aims to develop photoanode material required by dye-sensitized solar cells. The material prepared is in the form of Ag@TiO2core-shell-type nanocomposites. This material is used to replace the titanium oxide powder commonly used in general DSSCs. The prepared Ag@TiO2core-shell-type nanocomposites are mixed with Degussa P25 TiO2in different proportions. Triton X-100 is added and polyethylene glycol (PEG) at 20 wt% is used as a polymer additive. This study tests the particle size and material properties of Ag@TiO2core-shell-type nanocomposites and measures the photoelectric conversion efficiency and IPCE of DSSCs. Experimental results show that the DSSC prepared by Ag@TiO2core-shell-type nanocomposites can achieve a photoelectric conversion efficiency of 3.67%. When Ag@TiO2core-shell-type nanocomposites are mixed with P25 nanoparticles in specific proportions, and when the thickness of the photoelectrode thin film is 28 μm, the photoelectric conversion efficiency can reach 6.06%, with a fill factor of 0.52, open-circuit voltage of 0.64V, and short-circuit density of 18.22 mAcm−2. Compared to the DSSC prepared by P25 TiO2only, the photoelectric conversion efficiency can be raised by 38% under the proposed approach.

Core–Shell Chain-Like Cu@Ni Composite with Dual Absorption Peaks to Improve Microwave Absorption Properties

NANO ◽  
2018 ◽  
Vol 13 (05) ◽  
pp. 1850052
Author(s):  
Yuanyuan Zhou ◽  
Jianying Deng ◽  
Shimei Li ◽  
Zefeng Li
Keyword(s):  
Hydrothermal Reaction ◽  
Low Cost ◽  
Electromagnetic Properties ◽  
Formation Mechanisms ◽  
Core Shell ◽  
The Novel ◽  
Redox Potentials ◽  
X Ray Diffraction ◽  
Ni Alloy ◽  
Absorbing Material

Core–shell Cu@Ni chains were successfully synthesized through a mild hydrothermal reaction. The morphology, structure and microwave electromagnetic properties of the composite were then characterized by X-ray diffraction, energy-dispersive spectroscopy, scanning electron microscopy and vector network analysis. The formation mechanisms of the core–shell structure and one-dimensional chains were ascribed to the varying redox potentials of Cu and Ni ions and the magnetic dipole–dipole attraction. Furthermore, a minimal reflection loss (RL) of [Formula: see text]20.7[Formula: see text]dB was observed at 9.6[Formula: see text]GHz with a thickness of 2.0[Formula: see text]mm and the effective absorption ([Formula: see text]10[Formula: see text]dB, 90% microwave attenuation) bandwidth can be adjusted between 5.2[Formula: see text]GHz and 16.6[Formula: see text]GHz for the thin absorber thickness of 2.0–4.0[Formula: see text]mm. The novel core–shell chain-like Cu@Ni alloy can be used as a promising absorbing material because it shows numerous features such as thin thickness, strong absorption, low cost and lightweight.

Effect of Metal Gradient In Nano Wall of Stratified Type Photocatalyst

2009 ◽  
Vol 631-632 ◽  
pp. 339-344
Author(s):  
Tsugumi Hayashi ◽  
Yohei Baba ◽  
Toshiharu Taga ◽  
Shun Yokoyama ◽  
Hiroaki Suzuki ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Detailed Analysis ◽  
Crystalline Structure ◽  
Visible Light Irradiation ◽  
High Photocatalytic Activity ◽  
Core Shell ◽  
Shell Type ◽  
Metal Element ◽  
Egg Shell

Objective of study was the development of core-shell type ZnS-CdS photocatalyst with the stratified morphology. To form the stratified morphology, condition of the precursor is extremely important. For this purpose, three types of precursors, thus core-shell type, egg-shell type and uniform type, was tried to synthesize by utilizing the results of the calculation. The size of the synthesized precursor particles was about 40-100 nm. Main phase of the particle was gradually changed from ZnO (pH8.0) to Cd(OH)2 (pH9.5). Detailed analysis of the synthesized precursor was clearly demonstrated that these have the crystalline structure and each metal element was co-existed in one particle. Therefore, it could be concluded that core-shell type or uniform type precursor was successfully synthesized. Core-shell type ZnS-CdS stratified photocatalyst could be successfully synthesized by sulfurization for 1h, and it shows the high photocatalytic activity under visible light irradiation.

Statistical Modeling, Optimization and Kinetics of Mn2+ Adsorption in Aqueous Solution Using a Biosorbent

2019 ◽  
Vol 233 (8) ◽  
pp. 1201-1214 ◽  
Author(s):  
Elaheh Tajari ◽  
Narges Samadani Langeroodi ◽  
Mahnaz Khalafi
Keyword(s):  
Wheat Bran ◽  
Low Cost ◽  
Weight Ratio ◽  
P Value ◽  
Core Shell ◽  
Optimal Conditions ◽  
Solution Ph ◽  
Shell Weight ◽  
Removal Ratio ◽  
Kinetics Of

Abstract This paper describes the adsorption of Mn2+ ions from water with a mixture of wheat bran and Japanese medlar core shell (weight ratio of 30–70 wheat bran to Japanese medlar core shell) as low-cost adsorbent. Scanning Electron Microscope was used to characterize the adsorbent. The response surface methodology (RSM) that is usually approximated by a second-order regression model was employed to evaluate the effects of solution pH, initial Mn2+ concentration, adsorbent weight and contact time on the removal ratio of the Mn2+ ions. In this regard, the significant variables initial Mn2+ ions concentration, pH, adsorbent weight and square pH were found based on the small P-value for the model coefficients. The predicted optimal conditions were also performed. In the process optimization, maximal value of the removal ratio of Mn2+ was achieved as 96.91%. Additionally, this paper discusses the kinetic of adsorption in optimal conditions.

scholarly journals Improvement of Hydrogen Desorption Characteristics of MgH2 With Core-shell Ni@C Composites

Molecules ◽  
2018 ◽  
Vol 23 (12) ◽  
pp. 3113 ◽  
Author(s):  
Cuihua An ◽  
Qibo Deng
Keyword(s):  
Low Cost ◽  
Hydrogen Desorption ◽  
Core Shell ◽  
Desorption Kinetics ◽  
Hydrogen Storage Materials ◽  
High Hydrogen ◽  
Dehydrogenation Kinetics ◽  
Materials Research ◽  
High Theoretical Capacity ◽  
Kinetics Of

Magnesium hydride (MgH2) has become popular to study in hydrogen storage materials research due to its high theoretical capacity and low cost. However, the high hydrogen desorption temperature and enthalpy as well as the depressed kinetics, have severely blocked its actual utilizations. Hence, our work introduced Ni@C materials with a core-shell structure to synthesize MgH2-x wt.% Ni@C composites for improving the hydrogen desorption characteristics. The influences of the Ni@C addition on the hydrogen desorption performances and micro-structure of MgH2 have been well investigated. The addition of Ni@C can effectively improve the dehydrogenation kinetics. It is interesting found that: i) the hydrogen desorption kinetics of MgH2 were enhanced with the increased Ni@C additive amount; and ii) the dehydrogenation amount decreased with a rather larger Ni@C additive amount. The additive amount of 4 wt.% Ni@C has been chosen in this study for a balance of kinetics and amount. The MgH2-4 wt.% Ni@C composites release 5.9 wt.% of hydrogen in 5 min and 6.6 wt.% of hydrogen in 20 min. It reflects that the enhanced hydrogen desorption is much faster than the pure MgH2 materials (0.3 wt.% hydrogen in 20 min). More significantly, the activation energy (EA) of the MgH2-4 wt.% Ni@C composites is 112 kJ mol−1, implying excellent dehydrogenation kinetics.

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