Preparation of TiO2-g-Polystyrene Nanosphere and its Application in Toughening PS Matrix

2010 ◽  
Vol 97-101 ◽  
pp. 1677-1680 ◽  
Author(s):  
Xiao Ming Sang ◽  
Peng Wu ◽  
Gui Xiang Hou ◽  
Shou Wu Yu
Keyword(s):  
Impact Strength ◽  
Core Shell ◽  
Gravimetric Analysis ◽  
Nano Tio2 ◽  
Shell Nanoparticles ◽  
Maximum Value ◽  
Transmission Electron ◽  
Electron Microscopes ◽  
Core Shell Nanoparticles ◽  
The Impact

TiO2-g-Polystyrene(PS) nano-microspheres were prepared by grafted styrene monomer on the surface of nano-TiO2 particles via emulsion polymerization, and its surface and morphology were studied by Transmission electron microscopes(TEM), Fourier transform infrared spectroscopy(FTIR) and thermal gravimetric analysis(TGA). The results showed that the TiO2-g-PS nano-microsphere had a structure of sphericity composed of TiO2 and PS as core and shell respectively. The core-shell nanoparticles were subsequently used as filler in a PS matrix, and the impact strength of the TiO2-g-PS/PS composites were studied. The results showed that the impact strength of the composite material could be improved obviously, the maximum value of impacted strength of the TiO2-g-PS/PS was 1.75kJ/m2, which was 180% higher than that of pure PS. Drawing from the results, it could be confirmed that these core-shell TiO2-g-PS nanosphere fillers could toughen the PS matrix.

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.

Miscibility, morphology, mechanical, and thermodynamic properties of epoxy resins toughened with functionalized core-shell nanoparticles containing epoxy groups on the surface

2013 ◽  
Vol 43 (1) ◽  
pp. 8-18 ◽  
Author(s):  
Xugang Zhang ◽  
Bin Zhang ◽  
Mingming Sun ◽  
Jianhui Li ◽  
Lei Wang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Impact Strength ◽  
Thermodynamic Properties ◽  
Thermal Resistance ◽  
Epoxy Resins ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
Content Type ◽  
Core Shell Nanoparticles ◽  
Epoxy Groups

Purpose – In order to obtain functionalized core-shell nanoparticles (CSNPs) as excellent toughening agents for epoxy resins. The paper aims to discuss these issues. Design/methodology/approach – Functionalized CSNPs containing epoxy groups on the surface were synthesized by emulsion polymerization with butyl acrylate as the core and methyl methacrylate copolymerizing with glycidyl methacrylate (GMA) as the shell. CSNPs were used as toughening agents for epoxy resins and their chemical structure was characterized by FT-IR. The morphology of modified epoxy networks (MEPN) was analyzed by SEM and TEM. Both the mechanical properties and thermodynamic properties were studied. Findings – The results show that nearly spherical CSNPs with the particle size of 50-100 nm are obtained. A certain amount of CSNPs are uniformly dispersed in epoxy resins by the grinding method and the MEPN shows the ductile fracture feature. The miscibility between CSNPs and epoxy matrix increases with the increase of GMA concentration which makes more bonds form between them. Epoxy resins toughened with 10 wt% CSNPs containing 10 wt% GMA show the best mechanical properties and the increase in tensile strength and impact strength of the MEPN is 13.5 and 59.7 percent, respectively, over the unmodified epoxy networks. And the improvement in impact strength is not accompanied with loss of thermal resistance. Practical implications – The MEPN can be used as high-performance materials such as adhesives, sealants and matrixes of composites. Originality/value – The functionalized CSNPs are novel and it can greatly increase the toughness of epoxy resins without loss of thermal resistance.

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.

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.

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.

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.

scholarly journals Process Optimization for the Synthesis of Silver (AgNPs), Iron Oxide (α-Fe2O3NPs) and Core-Shell (Ag-Fe2O3CNPs) Nanoparticles Using the Aqueous Extract of Alstonia Scholaris: A Greener Approach

2018 ◽  
Vol 12 (1) ◽  
pp. 29-39 ◽  
Author(s):  
Navinchandra G. Shimpi ◽  
Mujahid Khan ◽  
Sharda Shirole ◽  
Shriram Sonawane
Keyword(s):  
Fourier Transform ◽  
Iron Oxide ◽  
Aqueous Extract ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
Alstonia Scholaris ◽  
Transmission Electron ◽  
Infra Red ◽  
High Level ◽  
Core Shell Nanoparticles

Objective:The present study is deals with the green synthesis of silver (AgNPs), iron oxide (α-Fe2O3NPs) and core-shell (Ag-α-Fe2O3CNPs) nanoparticles using the aqueous extract ofAlstonia scholariswithout any catalyst, template or surfactant or any intermediate under ultrasound cavitation technique. The purpose was to facilitate the high level of dispersion with increase in rate of reaction. Further AgNPs and α-Fe2O3NPs were used to synthesis Ag-Fe2O3CNPs in aqueous extract ofAlstonia scholarisunder controlled ultrasound cavitation technique.Methods:The size of AgNPs and Ag-Fe2O3CNPs can be tuned by optimizing various reaction parameters. UV-visible, X-ray diffraction spectroscopy (XRD), Transmission electron microscopy (TEM), Field emission scanning electron microscope (FE-SEM) and Fourier transform infra-red spectroscopy has been used for the characterization of silver and core shell Ag@Fe2O3nanoparticles. TEM images clearly show the formation of core shell nanoparticles with spherical morphology.Result:Fourier transform infra-red spectroscopy analysis revealed that carbohydrate, polyphenols, and protein molecules were involved in the synthesis and capping of silver, iron oxide and Ag@Fe2O3CNPs.

scholarly journals Conjugation of oligo-His peptides to magnetic γ-Fe2O3@SiO2 core-shell nanoparticles promotes their access to the cytosol

2021 ◽  
Author(s):  
Mathilde Le Jeune ◽  
Emilie Secret ◽  
Michaël Trichet ◽  
Aude Michel ◽  
Delphine Ravault ◽  
...  
Keyword(s):  
Cell Penetrating Peptides ◽  
Endosomal Escape ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
Heating Efficiency ◽  
Multiple Substrates ◽  
Transmission Electron ◽  
Cell Penetrating ◽  
Calcein Leakage ◽  
Core Shell Nanoparticles

The endosomal entrapment of functional nanoparticles is a severe limitation to their use for biomedical applications. In the case of magnetic nanoparticles (MNPs), this entrapment leads to poor heating efficiency for magnetic hyperthermia and suppresses the possibility to manipulate them in the cytosol. Current strategies to limit their entrapment are based on their functionalization with cell-penetrating peptides in order to promote their translocation directly across the cell membrane or their endosomal escape. However, these strategies suffer from potential release of free peptides in cell and to the best of our knowledge there is currently a lack of effective methods for the cytosolic delivery of MNPs after incubation with cells. Herein, we report the conjugation of fluorescently labelled cationic peptides to γ-Fe2O3@SiO2 core-shell nanoparticles by click chemistry to improve MNP access to the cytosol. We compare the effect of Arg9 and His4 peptides. On one hand, Arg9 is a classical cell-penetrating peptide, able to enter cells by direct translocation and on the other hand, it has been demonstrated that sequences rich in histidine residues promote endosomal escape, most probably by the proton sponge effect. The methodology developed allows to have a high co-localization of the peptides and core-shell nanoparticles in cells and to attest that the grafting onto nanoparticles of peptides rich in histidine promotes NP access to the cytosol. The endosomal escape was confirmed by a calcein leakage assay and by ultrastructural analysis in transmission electron microscopy. No toxicity of the nanoparticles functionalized with peptides was found. We show that our conjugation strategy is compatible with the addition of multiple substrates and can thus be used for the delivery of cytoplasm-targeted therapeutics.

Synthesis and Characterization of Fe/Nd2O3 Core–Shell Nanoparticles by Hydrogen Plasma-Metal Reaction

2006 ◽  
Vol 6 (3) ◽  
pp. 743-747 ◽  
Author(s):  
Tong Liu ◽  
Shicheng Zhang ◽  
Xingguo Li
Keyword(s):  
Hydrogen Plasma ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
X Ray ◽  
Nanoparticle Surface ◽  
Transmission Electron ◽  
Potential Applications ◽  
Catalytic Fields ◽  
Core Shell Nanoparticles

Fe/Nd2O3 core–shell nanoparticles (CSNs) with a mean diameter of 35 nm were produced successfully by using hydrogen plasma-metal reaction (HPMR) method. This core–shell structure was confirmed by high resolution transmission electron microscopy (HRTEM), energy dispersion X-ray spectroscopy (EDS), X-ray photoelectron spectral (XPS), and induction-coupled plasma (ICP) spectroscopy. The magnetic properties were measured by vibrating sample magnetometer (VSM). It was found that the mole ratio of Nd to Fe on the nanoparticle surface is 1.2:1, about 7 times of that of the whole nanoparticle. The saturation magnetization Ms and remanence Mr of Fe/Nd2O3 nanoparticles decrease prominently from Fe nanoparticles, whereas the coercivity HC drops only less than 5% of Fe nanoparticle. These CSNs have potential applications in magnetic and catalytic fields.

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