Silica/Polyurea Composite: Preparation, Characterization and Study of Dielectric Constant

2016 ◽  
Vol 13 (10) ◽  
pp. 7234-7237
Author(s):  
Botong Wang ◽  
Zebo Xu ◽  
Zhiqiang Wang
Keyword(s):  
Electron Microscopy ◽  
Dielectric Constant ◽  
Hydrogen Bonds ◽  
Ultraviolet Spectroscopy ◽  
Core Shell ◽  
X Ray Diffraction ◽  
Modified Silica ◽  
X Ray ◽  
Transmission Electron ◽  
Core Shell Structure

Silica/polyurea composite was prepared after surface modification of silica nanoparticles. Silica/polyurea composite was characterized by Fourier-transform infrared spectroscopy, ultraviolet spectroscopy, X-ray diffraction and transmission electron microscopy. The results indicate that the helical polyurea has been successfully grafted onto the surfaces of the modified silica. Silica/polyurea composite exhibits clearly core–shell structure. The ultraviolet absorption and crystallizability of silica/polyurea are changed due to the shell of helical polyurea, which possesses regular singlehanded conformation and interchain hydrogen bonds. The dielectric constant of silica/polyurea was also investigated. The result indicates that the interfacial interactions between organic shell and inorganic core increase the dielectric constant value being increased to 6.42 for silica/polyurea. The interchain hydrogen bonds of helical polyurea could also be the reason for the increasing of dielectric constant.

Enhancement of durability of NIR emission of Ag2S@ZnS QDs in water

2017 ◽  
Vol 31 (32) ◽  
pp. 1750297 ◽  
Author(s):  
M. Karimipour ◽  
M. Bagheri ◽  
M. Molaei
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Xrd Analysis ◽  
Core Shell ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Nir Emission ◽  
Core Shell Structure ◽  
Phase Transmission

Stability of Ag2S@ZnS QDs in water is a crucial concern for their application in biology. In this work, both physical sustainability and emission stability of Ag2S QDs were enhanced using parameter optimization of a pulsed microwave irradiation (MI) method up to 105 days after their preparation. UV–Vis and photoluminescence spectroscopies depicted an absorption and emission about 817 nm and 878 nm, respectively. X-ray diffraction (XRD) analysis showed a growth of Ag2S acanthite phase. Transmission Electron Microscopy (TEM) images revealed a clear formation of Ag2S@ZnS core–shell structure.

scholarly journals Crystallization of BaF2 from droplets of phase separated glass – evidence of a core–shell structure by ASAXS

CrystEngComm ◽  
2020 ◽  
Vol 22 (30) ◽  
pp. 5031-5039
Author(s):  
Armin Hoell ◽  
Vikram Singh Raghuwanshi ◽  
Christian Bocker ◽  
Andreas Herrmann ◽  
Christian Rüssel ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Small Angle ◽  
Shell Structure ◽  
Core Shell ◽  
X Ray Diffraction ◽  
X Ray ◽  
X Ray Scattering ◽  
Transmission Electron ◽  
Core Shell Structure

Glasses with the mol% compositions 1.88 Na2O·15.04 K2O·7.52 Al2O3·69.56 SiO2·6.00 BaF2 and 1.88 Na2O·15.03 K2O·7.52 Al2O3·69.52 SiO2·6.00 BaF2·0.05 SmF3 were studied using X-ray diffraction, transmission electron microscopy, and anomalous small-angle X-ray scattering.

Synthesis of Trilaminar Core–Shell Au/α-Fe2O3@SnO2Nanocomposites and their Application for Nonenzymatic Dopamine Electrochemical Sensing

NANO ◽  
2019 ◽  
Vol 14 (11) ◽  
pp. 1950138 ◽  
Author(s):  
Sai Zhang ◽  
Shijun Yue ◽  
Jiajia Li ◽  
Jianbin Zheng ◽  
Guojie Gao
Keyword(s):  
Electron Microscopy ◽  
High Sensitivity ◽  
Electrochemical Sensing ◽  
Synthesis Process ◽  
Core Shell ◽  
X Ray Diffraction ◽  
X Ray ◽  
Long Term Stability ◽  
Transmission Electron

Au nanoparticles anchored on core–shell [Formula: see text]-Fe2O3@SnO2 nanospindles were successfully constructed through hydrothermal synthesis process and used for fabricating a novel nonenzymatic dopamine (DA) sensor. The structure and morphology of the Au/[Formula: see text]-Fe2O3@SnO2 trilaminar nanohybrid film were characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM) and X-ray diffraction (XRD). The electrochemical properties of the sensor were investigated by cyclic voltammetry and amperometry. The experimental results suggest that the composites have excellent catalytic property toward DA with a wide linear range from 0.5[Formula: see text][Formula: see text]M to 0.47[Formula: see text]mM, a low detection limit of 0.17[Formula: see text][Formula: see text]M (S/[Formula: see text]) and high sensitivity of 397.1[Formula: see text][Formula: see text]A[Formula: see text]mM[Formula: see text][Formula: see text]cm[Formula: see text]. In addition, the sensor exhibits long-term stability, good reproducibility and anti-interference.

One-pot microwave assisted approach for synthesis of CdSe/CdS core-shell quantum dots (QDs) and investigating optical properties

2016 ◽  
Vol 30 (07) ◽  
pp. 1650074 ◽  
Author(s):  
M. Molaei ◽  
F. Salari Bardsiri ◽  
A. R. Bahador ◽  
M. Karimipour
Keyword(s):  
Core Shell ◽  
Heat Sensitivity ◽  
X Ray Diffraction ◽  
Cdse Qds ◽  
One Pot ◽  
X Ray ◽  
Microwave Assisted ◽  
Transmission Electron ◽  
Core Shell Structure ◽  
Microwave Assisted Method

In this work, CdSe QDs were synthesized using a microwave assisted method and chemical reaction between NaHSe, CdSO4 at the presence of TGA as capping molecule. Thereafter without CdSe extraction, CdS shell was grown subsequently around CdSe cores by a reaction based on the heat sensitivity of Na2S2O3 dissociation. Synthesized QDs were characterized by means of X-ray diffraction spectroscopy (XRD), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), UV–Vis and photoluminescence (PL) spectroscopy. All of these analyzes confirmed formation of CdSe QDs and successfully growth of CdS shell on surface of CdSe to forming CdSe/CdS core-shell structure.

Study the Effect of HAp Content in PLA/HAp Microsphere on the Efficiency of Drug (Clindamycin) Loading Process

2013 ◽  
Vol 834-836 ◽  
pp. 559-562 ◽  
Author(s):  
Juntima Pradid ◽  
Wirunya Keawwattana ◽  
Siree Tangbunsuk
Keyword(s):  
Electron Microscopy ◽  
Thermal Process ◽  
High Performance ◽  
Core Shell ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ultrasound Field ◽  
Sample Characterization ◽  
Core Shell Structure ◽  
Scanning Electron

An ultrasound field was applied to obtain Polylactic acid (PLA)/Hydroxyapatite (HAp) biocomposite microspheres with the specific core-shell structure to be applied as a carrier of a drug. The hydroxyapatite was obtained from crocodile bone by thermal process. Sample characterization was achieved by powder X-ray diffraction (XRD), Energy-dispersive X-ray spectroscopy (EDX) Scanning electron microscopy (SEM) and High Performance Liquid Chromatography (HPLC). As the result, the PLA/HAp loading clindamycin with different polymer-to-ceramic part wt.% ratio (100:0, 90:10, 80:20, and 70:30) showed the agglomeration of sphere-like particles. In addition, the loading efficiency of clindamycin increased with increasing HAp content up to 20%.

Fast Synthesis of Rutile/Apatite Core/Shell Structured Photocatalyst in Simulated Body Fluid

2012 ◽  
Vol 465 ◽  
pp. 66-71 ◽  
Author(s):  
Fu Zhi Shi ◽  
Yao Gang Li ◽  
Hong Zhi Wang ◽  
Qing Hong Zhang
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Simulated Body Fluid ◽  
Body Fluid ◽  
Core Shell ◽  
X Ray Diffraction ◽  
Soaking Time ◽  
X Ray ◽  
Transmission Electron ◽  
Tio2 Microspheres

The core/shell structured rutile/apatite was prepared by soaking rutile TiO2 (R-TiO2) microspheres into a simulated body fluid (SBF) only for 1 day. The as-prepared samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), energy dispersive X-ray (EDX) and N2 adsorption measurements. XRD showed that the apatite content increased with prolonging the soaking time or increasing the SBF concentration. TEM and EDX demonstrated that apatite had been coated on the surface of R-TiO2 microspheres successfully. HRTEM indicated that the lattice spacings of 0.27 nm and 0.32 nm were assigned to (211) plane of apatite and (101) plane of R-TiO2, respectively.

Growth and characterization of type II ZnO/ZnSe core/shell nanowire arrays

2010 ◽  
Vol 25 (7) ◽  
pp. 1272-1277 ◽  
Author(s):  
Jinjian Zheng ◽  
Zhiming Wu ◽  
Weihuang Yang ◽  
Shuping Li ◽  
Junyong Kang
Keyword(s):  
Electron Microscopy ◽  
Chemical Vapor ◽  
Band Alignment ◽  
Nanowire Arrays ◽  
Core Shell ◽  
Type Ii ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Potential Applications

Type II ZnO/ZnSe core/shell nanowire arrays were grown by a two-step chemical vapor deposition. The nanowire arrays with dense nanoislands on the surface are well aligned and normal to the substrate imaged by scanning electron microscopy. The core/shell structure of nanowires was identified by a high-resolution transmission electron microscopy. The structure and composition of the shell were confirmed to be wurtzite ZnSe by x-ray diffraction, Raman scattering and energy-dispersive x-ray spectroscopy. Moreover, an intense emission was observed at 1.89 eV smaller than the band gaps of core and shell materials by photoluminescence, indicating the achievement of the type II band alignment at the interface. This study is expected to contribute to the potential applications in novel photovoltaic devices.

Effect of protamine on Fe3O4@CS@GFTN composite magnetic nanoparticles

2019 ◽  
Vol 13 (02) ◽  
pp. 2050001 ◽  
Author(s):  
Huiping Shao ◽  
Luhui Wang ◽  
Tao Lin ◽  
Yumeng Zhang ◽  
Zhinan Zhang
Keyword(s):  
Magnetic Nanoparticles ◽  
Shell Structure ◽  
Lung Diseases ◽  
Core Shell ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Core Shell Structure ◽  
Average Size ◽  
Chemical Coprecipitation Method

Fe3O4@chitosan (CS)@Gefitinib (GFTN) core-shell structure composite magnetic nanoparticles (NPs) were prepared by chemical coprecipitation method in this study. In addition, protamine was doped in Fe3O4 cores to prepare Fe3O4@protamine@CS@GFTN core-shell structure composite NPs, in order to increase the loading of GFTN in composite NPs. They were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), vibrating sample magnetometer (VSM) and spectrophotometer. The results show that the average size of Fe3O4@CS@GFTN and Fe3O4@protamine@CS@GFTN composite NPs is approximately 19 and 21[Formula: see text]nm, respectively. The saturation magnetizations of composite magnetic NPs and corresponding magnetic fluids are 57.20, 20.79, 59.58 and 19.75[Formula: see text]emu/g, respectively. The loading of GFTN in composite NPs was measured by a spectrophotometer to be about 13.5% and 27.6%, respectively. The addition of protamine increased the loading of GFTN two times, indicating that it will play an important role in the management of lung diseases.

Preparation and Properties of ZnO@ZnS Nano-Array Core-Shell Structure with Different Concentration of TAA

2013 ◽  
Vol 652-654 ◽  
pp. 683-686
Author(s):  
An Dong Yuan ◽  
Yue Lu Zhang ◽  
Wei Guang Yang ◽  
Ji Rong Li ◽  
Yang Liao ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Shell Structure ◽  
Solution Method ◽  
Deionized Water ◽  
Shell Structures ◽  
Core Shell ◽  
X Ray Diffraction ◽  
X Ray ◽  
Core Shell Structure ◽  
Scanning Electron

ZnO@ZnS nano-array core-shell structure was synthesized through a solution method using a thioacetamide (TAA) solution in deionized water. The as-synthesized ZnO nano-array and TAA solution were employed to supply zinc and sulfur ions to form the ZnO@ZnS core-shell structures. The properties of the structure were characterized by X-ray diffraction (XRD), Raman spectrum, scanning electron microscopy (SEM) and UV-Vis spectra. The results indicate that ZnO nano-array was coated with ZnS particles. The concentration of TAA solution can affect the diameter, surface roughness and optical properties of the ZnO@ZnS nano-array core-shell structures.

Sign in / Sign up

Export Citation Format

Share Document