scholarly journals Morphological Studies of Composite Spin Crossover@SiO2 Nanoparticles

Nanomaterials ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3169
Author(s):  
Yue Zan ◽  
Lionel Salmon ◽  
Azzedine Bousseksou
Keyword(s):  
Spin Crossover ◽  
Magnetic Measurements ◽  
Variable Temperature ◽  
Sio2 Nanoparticles ◽  
Silica Shell ◽  
Polar Phase ◽  
Shell Nanoparticles ◽  
Morphological Studies ◽  
Transmission Electron ◽  
Core Shell Nanoparticles

Spin crossover (SCO) iron (II) 1,2,4-triazole-based coordination compounds in the form of composite SCO@SiO2 nanoparticles were prepared using a reverse microemulsion technique. The thickness of the silica shell and the morphology of the as obtained core@shell nanoparticles were studied by modifying the polar phase/surfactant ratio (ω), as well as the quantity and the insertion phase (organic, aqueous and micellar phases) of the tetraethylorthosilicate (TEOS) precursor, the quantity of ammonia and the reaction temperature. The morphology of the nanoparticles was monitored by transmission electron microscopy (TEM/HRTEM) while their composition probed by combined elemental analyses, thermogravimetry and EDX analyses. We report that not only the particle size can be controlled but also the size of the silica shell, allowing for interesting perspectives in post-synthetic modification of the shell. The evolution of the spin crossover properties associated with the change in morphology was investigated by variable temperature optical and magnetic measurements.

Synthesis of Co@Au Core-Shell Nanoparticles in Non-Aqueous Solution and their Characterization

2004 ◽  
Vol 818 ◽  
Author(s):  
Zhihui Ban ◽  
C. J. O'Connor
Keyword(s):  
Aqueous Solution ◽  
Quantum Interference ◽  
Au Nanoparticles ◽  
Magnetic Measurements ◽  
Core Shell ◽  
X Ray Diffraction ◽  
Shell Nanoparticles ◽  
Transmission Electron ◽  
Average Size ◽  
Core Shell Nanoparticles

AbstractA homogeneous non-aqueous solution reactions method has been developed to prepare gold-coated cobalt (Co@Au) nanoparticles. After the sample was washed with 8% HCl, XRD (X-Ray Diffraction), TEM (transmission electron microscopy), and magnetic measurements SQUID (Superconducting Quantum Interference Device) are utilized to characterize the nanocomposites. XRD shows the pattern of sample, which is responding to gold and cobalt, no cobalt oxide was found. TEM results show that the average size of Co@Au nanoparticles is about 10 nm and we can find core-shell structure of the sample. SQUID results show that the particles are ferromagnetic materials at 300K. So the gold- coated cobalt nanoparticles (Co@Au) can be successfully prepared by the homogeneous nonaqueous approach. This kind of core-shell materials is stable in acid condition, which would give many opportunities for bio- application.

Monodisperse Fe3O4/Fe Core/Shell Nanoparticles with Enhanced Magnetic Property

2011 ◽  
Vol 306-307 ◽  
pp. 410-415
Author(s):  
Li Sun ◽  
Fu Tian Liu ◽  
Qi Hui Jiang ◽  
Xiu Xiu Chen ◽  
Ping Yang
Keyword(s):  
Average Diameter ◽  
Chemical Precipitation ◽  
Precipitation Method ◽  
Core Shell ◽  
X Ray Diffraction ◽  
Shell Nanoparticles ◽  
X Ray ◽  
Transmission Electron ◽  
Shell Particles ◽  
Core Shell Nanoparticles

Core/shell type nanoparticles with an average diameter of 20nm were synthesized by chemical precipitation method. Firstly, Monodisperse Fe3O4 nanoparticles were synthesized by solvethermal method. FeSO4ž7H2O and NaBH4 were respectively dissolved in distilled water, then moderated Fe3O4 particles and surfactant(PVP) were ultrasonic dispersed into the FeSO4ž7H2O solution. The resulting solution was stirred 2 h at room temperature. Fe could be deposited on the surface of monodispersed Fe3O4 nanoparticles to form core-shell particles. The particles were characterized by using various experimental techniques, such as transmission electron microscopy (TEM), X-ray diffraction (XRD), AGM and DTA. The results suggest that the saturation magnetization of the nanocomposites is 100 emu/g. The composition of the samples show monodisperse and the sides of the core/shell nanoparticles are 20-30nm. It is noted that the formation of Fe3O4/Fe nanocomposites magnetite nanoparticles possess superparamagnetic property.

scholarly journals Magnetite–Corrole Hybrid Nanoparticles

2018 ◽  
Vol 4 (3) ◽  
pp. 37
Author(s):  
Rute Pereira ◽  
Tito Trindade ◽  
Joana Barata
Keyword(s):  
Magnetite Nanoparticles ◽  
Silica Coating ◽  
Hybrid Nanoparticles ◽  
Hydrothermal Route ◽  
Shell Nanoparticles ◽  
Lower Efficiency ◽  
Oxygen Generation ◽  
Transmission Electron ◽  
Pyridine Complex ◽  
Core Shell Nanoparticles

This study describes the first example of a hybrid material comprising corrole- and silica-coated magnetite nanoparticles. Firstly, cuboid and spheroid magnetite nanoparticles were prepared using a simple hydrothermal route, followed by a silica coating. The hybrid nanoparticles were obtained by promoting a covalent link between a gallium (III)(pyridine) complex of 5,10,15-tris(pentafluorophenyl)corrole (GaPFC) and the surface of magnetite–silica core/shell nanoparticles (Fe3O4@SiO2), shaped both as cuboids and spheroids. The hybrids were characterized using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), ultraviolet-visible spectrophotometry (UV-Vis) and transmission electron microscopy (TEM). Preliminary studies on the capacity of singlet oxygen generation of the hybrid nanoparticles showed that these have lower efficiency values when compared to the pure corrole compound.

scholarly journals Development of NIPAAm-PEG acrylate polymeric nanoparticles for co-delivery of paclitaxel with ellagic acid for the treatment of breast cancer

2019 ◽  
Vol 39 (3) ◽  
pp. 271-278 ◽  
Author(s):  
Suruchi Suri ◽  
Mohd. Aamir Mirza ◽  
Md. Khalid Anwer ◽  
Abdullah S. Alshetaili ◽  
Saad M. Alshahrani ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Particle Size ◽  
Ellagic Acid ◽  
Oral Delivery ◽  
Polymeric Nanoparticles ◽  
Entrapment Efficiency ◽  
Shell Nanoparticles ◽  
Transmission Electron ◽  
Core Shell Nanoparticles

Abstract The aim of the current study was to develop a dual-loaded core shell nanoparticles encapsulating paclitaxel (PTX) and ellagic acid (EA) by membrane dialysis method. Based on particle size, polydispersity index (PDI), and entrapment efficiency, the dual drug-loaded nanoparticles (F2) was optimized. The optimized nanoparticles (F2) showed a particle size of 140±2 nm and a PDI of 0.23±3. The size and the morphology were confirmed by transmission electron microscopy (TEM) and found agreement with the results of dynamic light scattering. The entrapment efficiencies of total drug (PTX and EA), PTX, and EA in the nanoparticles (F2) were measured as 80%, 62.3%, and 37.7%, respectively. The in vitro release profile showed a controlled release pattern for 48 h. A higher cytotoxicity was observed with nanoparticles (F2) in comparison to free PTX. The results revealed that co-delivery of PTX and EA could be used for its oral delivery for the effective treatment of breast cancer.

The Preparation and Characteristic of Superparamagnetic Core/Shell Nanoparticles

2013 ◽  
Vol 274 ◽  
pp. 432-435
Author(s):  
Hong Xia Shen ◽  
Zheng Zhi Yin ◽  
Qiong Cheng
Keyword(s):  
Biomedical Applications ◽  
Superparamagnetic Nanoparticles ◽  
Bioactive Molecules ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
X Ray ◽  
Transmission Electron ◽  
Vibration Sample Magnetometer ◽  
Diffraction Patterns ◽  
Core Shell Nanoparticles

Superparamagnetic core/shell nanoparticles have been prepared successfully by the reduction of Au3+ onto the surface of superparamagnetic nanoparticles. The core/shell nanoparticles were characterized by Transmission electron microscopy (TEM), X-ray powder diffraction patterns (XRD), UV–vis spectrophotometer, Vibration Sample Magnetometer(VSM) and micro-confocal Raman system. The results revealed that the prepared core/shell nanoparticles were covered by Au shell. These superparamagnetic nanoparticles can be highly sensitively detected and afford new opportunities for biomedical applications through chemical bonding of bioactive molecules with the Au shell of nanoparticles.

Preparation of ZnO@void@SiO2 Rattle Type Core–Shell Nanoparticles via Layer-by-Layer Method

NANO ◽  
2016 ◽  
Vol 11 (09) ◽  
pp. 1650103 ◽  
Author(s):  
Xiaoman Wang ◽  
Junda Song ◽  
Hongling Chen
Keyword(s):  
Sol Gel ◽  
Carbon Layer ◽  
Layer By Layer ◽  
X Ray Diffraction ◽  
Shell Nanoparticles ◽  
Hexagonal Wurtzite Crystal Structure ◽  
Transmission Electron ◽  
Measurement Results ◽  
Average Size ◽  
Core Shell Nanoparticles

In this paper, we prepared the rattle type nanoparticles ZnO@void@SiO2 by two successive coating processes, followed by heat treatment. The carbon layer was formed over ZnO surface with the aid of the hydrothermal treatment of glucose. Then the resulting composite was used to fabricate a silica shell on the surface by sol–gel method. Finally, ZnO particles were released but still trapped inside the silica hollow after calcination, that is, ZnO@void@SiO2. The composites were characterized by scanning and transmission electron microscope, N2 adsorption experiment, X-ray diffraction, Fourier transform infrared spectroscopy and UV-Vis absorption spectra. The rattle type structure was conformed and the sphere-like structure with the average size of 70 nm and hexagonal wurtzite crystal structure were also observed. The measurement results of optical properties showed even though ZnO@C@SiO2 presented no photocatalysis, ZnO@void@SiO2 showed high activity even the ZnO core was encapsulated with the SiO2 hollow.

Iron/Graphite Core-Shell Structured Nanoparticles Prepared by Annealing of Nanopowder

2005 ◽  
Vol 480-481 ◽  
pp. 469-476 ◽  
Author(s):  
B. David ◽  
N. Pizúrová ◽  
O. Schneeweiss ◽  
Petr Bezdička ◽  
I. Morjan ◽  
...  
Keyword(s):  
Magnetic Measurements ◽  
Iron Carbide ◽  
Iron Pentacarbonyl ◽  
Morphological Characterization ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
Annealed Material ◽  
Prepared Material ◽  
Core Shell Nanoparticles

We present magnetic and morphological characterization of iron- and iron-carbide- based nanopowder obtained by the laser synthesis from sensitized gas phase mixture containing acetylene and iron pentacarbonyl vapors. The analysis was performed on the as-prepared material and the annealed material. The results of TEM, XRD, Mössbauer and magnetic measurements are reported. Phase transformations taking place during annealing of the nanopowder when core-shell nanoparticles appear are discussed.

Characterization of a Porous Carbon Material Functionalized with Cobalt-Oxide/Cobalt Core-Shell Nanoparticles for Lithium Ion Battery Electrodes

MRS Advances ◽  
2016 ◽  
Vol 1 (15) ◽  
pp. 1061-1066
Author(s):  
Dalaver H. Anjum ◽  
Shahid Rasul ◽  
Manuel A. Roldan-Gutierrez ◽  
Pedro M. F. J. Costa
Keyword(s):  
Lithium Ion Battery ◽  
Cobalt Oxide ◽  
Lithium Ion ◽  
Oxide Shell ◽  
Porous Carbon Material ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
Transmission Electron ◽  
Core Shell Nanoparticles ◽  
Type Lattice

ABSTRACTA nanoporous carbon (C) material, functionalized with Cobalt-Oxide/Cobalt (CoO/Co) core-shell nanoparticles (NPs), was structurally and chemically characterized with transmission electron microcopy (TEM) while its electrochemical response for Lithium ion battery (LIB) applications was evaluated as well. The results herein show that the nanoporous C material was uniformly functionalized with the CoO/Co core-shell NPs. Further the NPs were crystalline with fcc-type lattice on the Co2+ oxide shell and hcp-type core of metallic Co0. The electrochemical study was carried out by using galvanostatic charge/discharge cycling at a current density of 1000 mA g−1. The potential of this hybrid material for LIB applications was confirmed and it is attributed to the successful dispersion of the Co2+/ Co0 NPs in the C support.

Silica-Polypyrrole Core–Shell Nanocomposites as Active Materials for Dielectrophoretic Displays

2008 ◽  
Vol 8 (9) ◽  
pp. 4353-4359 ◽  
Author(s):  
F. Miomandre ◽  
P. Audebert ◽  
J. P. Bonnet ◽  
A. Brosseau ◽  
P. Perriat ◽  
...  
Keyword(s):  
Conjugated Polymer ◽  
Light Transmission ◽  
Silica Shell ◽  
Core Shell ◽  
Gravimetric Analysis ◽  
Thermal Gravimetric ◽  
Active Materials ◽  
Shell Nanoparticles ◽  
Core Shell Nanoparticles ◽  
Electrorheological Properties

A direct route to silica-polypyrrole core–shell nanoparticles has been used to design new nanocomposites, in which the conducting part is then wrapped by an external silica shell in order to have finally neutral nanoparticles. The nanocomposites are characterized by TEM, spectroscopy, electrochemistry and thermal gravimetric analysis, demonstrating that the external silica shell actually insulates the conjugated polymer from the outer medium. Finally the electrorheological properties of these nanocomposites are checked in a dielectrophoretic device in which the motion of the particles induced by an external electric field can be used to monitor a switch of the light transmission properties.

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