scholarly journals Preparation, optical properties, and thermal stability of polyvinyl butyral composite films containing core (lanthanum hexaboride)–shell (titanium dioxide)-structured nanoparticles

2021 ◽  
Vol 28 (1) ◽  
pp. 605-612
Author(s):  
Hongbo Tang ◽  
Jian Zhou ◽  
Shengkui Zhong ◽  
Yuchang Su ◽  
Qunwei Shu ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Shell Structure ◽  
Near Infrared ◽  
Sol Gel ◽  
Visible Region ◽  
Polyvinyl Butyral ◽  
Lanthanum Hexaboride ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
Core Shell Structure

Abstract Nano-sized lanthanum hexaboride (LaB6)@ titanium dioxide (TiO2) particles with a core–shell structure has been successfully synthesized via a simple sol–gel method. LaB6@TiO2 particles were used as filler in polyvinyl butyral (PVB) matrix and performance of the TiO2 shell was evaluated. The core–shell nanoparticles were characterized for morphology and structure properties. X-ray diffraction and transmission electron microscope testing results confirm the formation of LaB6–TiO2 core–shell structure. In composite film, LaB6 improved the thermo-decomposing temperature of PVB matrix from 369.2 to 372.8°C, while the same amount of LaB6@TiO2 further increased the temperature to 381.0°C. In addition, TiO2 shell redshifted the maximum transmittance of the film from 605 to 669 nm in the visible region. In the near infrared region, its absorption peak shifted from 1,466 to 1,476 nm. This result will be helpful for the development of transparent and thermal insulating materials.

PREPARATION AND CHARACTERIZATION OF SURFACE-FUNCTIONALIZATION OF SILICA-COATED MAGNETITE NANOPARTICLES FOR DRUG DELIVERY

NANO ◽  
2014 ◽  
Vol 09 (04) ◽  
pp. 1450042 ◽  
Author(s):  
CONG-WANG ZHANG ◽  
CHANG-CHUN ZENG ◽  
YING XU
Keyword(s):  
Drug Delivery ◽  
Shell Structure ◽  
Drug Carrier ◽  
Point Of View ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
The Core ◽  
Application Potential ◽  
Core Shell Structure ◽  
Core Shell Nanoparticles

Fe 3 O 4– SiO 2 core–shell structure nanoparticles containing magnetic properties were investigated for their potential use in drug delivery. The Fe 3 O 4– SiO 2 core–shell structure nanoparticles were successfully synthesized by a simple and convenient way. The Fe 3 O 4– SiO 2 nanoparticles showed superparamagnetic behavior, indicating a great application potential in separation technologies. From the application point of view, the prepared nanoparticles were found to act as an efficient drug carrier. Specifically, the surface of the core–shell nanoparticles was modified with amino groups by use of silane coupling agent 3-aminopropyltriethoxysilane (APTS). Doxorubicin (DOX) was successfully grafted to the surface of the core–shell nanoparticles after the decoration with the carboxyl acid groups on the surface of amino-modified core–shell structure nanoparticles. Moreover, the nanocomposite showed a good drug delivery performance in the DOX-loading efficiency and drug release experiments, confirming that the materials had a great application potential in drug delivery. It is envisioned that the prepared materials are the ideal agent for application in medical diagnosis and therapy.

scholarly journals Synthesis and Comparative Biological Properties of Ag-PEG Nanoparticles with Tunable Morphologies from Janus to Multi-Core Shell Structure

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1787 ◽  
Author(s):  
Mengda Xu ◽  
Jie Liu ◽  
Xiankui Xu ◽  
Shanhu Liu ◽  
František Peterka ◽  
...  
Keyword(s):  
Polyethylene Glycol ◽  
Silver Nitrate ◽  
Shell Structure ◽  
Irradiation Time ◽  
Antibacterial Activities ◽  
Biological Properties ◽  
Hybrid Nanoparticles ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
Core Shell Structure

Silver nanoparticles synthesized with polymers as coating agents is an effective method to overcome their poor stability and aggregation in solution. Silver-polyethylene glycol (Ag-PEG) nanoparticles were synthesized with the thiol-functionalized polyethylene glycol (SH-PEA) as the coating, reducing and stabilizing agent. The UV irradiation time, polymer and silver nitrate concentration for the synthesis were investigated. The concentration of silver nitrate had significant effect on the morphology of Ag-PEG nanoparticles. When increasing the concentration of silver nitrate, SEM and TEM images showed that Ag-PEG nanoparticles changed from Janus to multi-core shell structure. Meanwhile, pure silver particles in the two hybrid nanoparticles presented spherical shape and had the similar size of 15 nm. The antibacterial activities and cytotoxicity of the two structural Ag-PEG nanoparticles were investigated to understand colloid morphology effect on the properties of AgNPs. The results of antibacterial activities showed that the two structural Ag-PEG nanoparticles exhibited strong antibacterial activities against Staphylococcus aureus, Escherichia coli and Bacillus subtilis. The Janus nanoparticles had larger minimal inhibitory concentration (MIC) and minimum bacterial concentration (MBC) values than the multi-core shell counterparts. The results of cytotoxicity showed the Janus Ag-PEG nanoparticles had lower toxicity than the multi-core shell nanoparticles.

The Preparation of Fluorescent Nano Dye-Silica Particles by Sol-Gel Process

2007 ◽  
Vol 124-126 ◽  
pp. 651-654 ◽  
Author(s):  
Young Joo Na ◽  
Sang Joon Park ◽  
Ji Hyeon Kim ◽  
Jong Sung Kim
Keyword(s):  
Shell Structure ◽  
Sol Gel ◽  
Silica Nanoparticle ◽  
Fluorescent Dye ◽  
Core Shell ◽  
Fluorescent Intensity ◽  
Sol Gel Process ◽  
Fluorescent Spectrum ◽  
Core Shell Structure ◽  
Trimethoxy Silane

The core-shell structure of dye-silica nanoparticle has been prepared. The dye-silica nanoparticle can be used as a substitute of fluorescent dye for bio analysis. The hybrid organicinorganic nanoparticle was prepared by sol-gel process using organic modified silane as the coupling agent for flourescent dye and silica. The size of the particle was about 50 nm, which was measured by DLS and confirmed by SEM photograph. The fluorescent dye (fluorescein-5-maleimide) was reacted with (3-mercaptopropyl) trimethoxy silane to produce dye-silane compound, followed by the sol-gel reaction with tetraethoxysilane(TEOS) and water to produce core-shell structure. The fluorescent spectrum showed that the fluorescent intensity of dye-silica nanoparticle was higher than that of fluorescent dye.

Preparation, Characterization and Visible-Light Catalytic Activity of Core-Shell Structure NiFe2O4@TiO2 Ferrite Nanoparticles

2016 ◽  
Vol 680 ◽  
pp. 272-277
Author(s):  
Zhou Li Lu ◽  
Peng Zhao Gao ◽  
Rui Xue Ma ◽  
Yu Kun Sun ◽  
Dong Yun Li
Keyword(s):  
Catalytic Activity ◽  
Visible Light ◽  
Shell Structure ◽  
Shell Thickness ◽  
Spinel Ferrite ◽  
Sol Gel ◽  
Magnetic Core ◽  
Core Shell ◽  
Calcination Temperatures ◽  
Core Shell Structure

The core-shell structure NiFe2O4@TiO2 nanoparticles was successfully prepared using a sol-gel method, the influence of shell thickness and calcination temperatures on the composition, microstructure, magnetic properties and visible-light catalytic activity of the nanoparticles was studied by XRD, TEM, Uv–vis, vibrating sample magnetometer, etc. Results showed the main composition of core in NiFe2O4@TiO2 was spinel ferrite, and the shell was anatase TiO2, and theshell thickness increased significantly with the increase of TiO2 content, ranging from 10nm to 50nm. The Ms and Mr of nanoparticles decreased with the increase of TiO2 content, and no obvious reaction between the magnetic core and shell occurred; visible-light degradation percent of NiFe2O4@TiO2 nanoparticles increased along with the increase of TiO2 content, whereas the recovery rate of it decreased. Degradation percent and the recovery percent of NiFe2O4@TiO2-50 still reached 93.7% and 90.5%, even after 10 cycle times, respectively, possessing the excellent long-term stability.

scholarly journals High Photocatalytic Activity of Fe3O4-SiO2-TiO2Functional Particles with Core-Shell Structure

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Chenyang Xue ◽  
Qiang Zhang ◽  
Junyang Li ◽  
Xiujian Chou ◽  
Wendong Zhang ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Photocatalytic Activity ◽  
Shell Structure ◽  
Sol Gel ◽  
High Photocatalytic Activity ◽  
Core Shell ◽  
Large Area ◽  
Uniform Size ◽  
Functional Nanoparticles ◽  
Core Shell Structure

This paper describes a novel method of synthesizing Fe3O4-SiO2-TiO2functional nanoparticles with the core-shell structure. The Fe3O4cores which were mainly superparamagnetic were synthesized through a novel carbon reduction method. The Fe3O4cores were then modified with SiO2and finally encapsulated with TiO2by the sol-gel method. The results of characterizations showed that the encapsulated 700 nm Fe3O4-SiO2-TiO2particles have a relatively uniform size distribution, an anatase TiO2shell, and suitable magnetic properties for allowing collection in a magnetic field. These magnetic properties, large area, relative high saturation intensity, and low retentive magnetism make the particles have high dispersibility in suspension and yet enable them to be recovered well using magnetic fields. The functionality of these particles was tested by measuring the photocatalytic activity of the decolouring of methyl orange (MO) and methylene blue (MB) under ultraviolet light and sunlight. The results showed that the introduction of the Fe3O4-SiO2-TiO2functional nanoparticles significantly increased the decoloration rate so that an MO solution at a concentration of 10 mg/L could be decoloured completely within 180 minutes. The particles were recovered after utilization, washing, and drying and the primary recovery ratio was 87.5%.

A BIO-INSPIRED POLYDOPAMINE APPROACH TO PREPARATION OF GOLD-COATED Fe3O4 CORE–SHELL NANOPARTICLES: SYNTHESIS, CHARACTERIZATION AND MECHANISM

NANO ◽  
2013 ◽  
Vol 08 (06) ◽  
pp. 1350061 ◽  
Author(s):  
PENG AN ◽  
FANG ZUO ◽  
XINHUA LI ◽  
YUANPENG WU ◽  
JUNHUA ZHANG ◽  
...  
Keyword(s):  
Shell Structure ◽  
Room Temperature ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
Stabilizing Agent ◽  
X Ray ◽  
Transmission Electron ◽  
Core Shell Structure ◽  
Core Shell Nanoparticles

A biomimetic and facile approach for integrating Fe 3 O 4 and Au with polydopamine (PDA) was proposed to construct gold-coated Fe 3 O 4 nanoparticles ( Fe 3 O 4@ Au – PDA ) with a core–shell structure by coupling in situ reduction with a seed-mediated method in aqueous solution at room temperature. The morphology, structure and composition of the core–shell structured Fe 3 O 4@ Au – PDA nanoparticles were characterized by transmission electron microscopy (TEM), X-ray powder diffraction (XRD) and X-ray photoelectron spectrometry (XPS). The formation process of Au shell was assessed using a UV-Vis spectrophotometer. More importantly, according to investigating changes in PDA molecules by Fourier transform infrared spectroscopy (FTIR) and in preparation process of the zeta-potential data of nanoparticles, the mechanism of core–shell structure formation was proposed. Firstly, PDA-coated Fe 3 O 4 are obtained using dopamine (DA) self-polymerization to form thin and surface-adherent PDA films onto the surface of a Fe 3 O 4 "core". Then, Au seeds are attached on the surface of PDA-coated Fe 3 O 4 via electrostatic interaction in order to serve as nucleation centers catalyzing the reduction of Au 3+ to Au 0 by the catechol groups in PDA. Accompanied by the deposition of Au , PDA films transfer from the surface of Fe 3 O 4 to that of Au as stabilizing agent. In order to confirm the reasonableness of this mechanism, two verification experiments were conducted. The presence of PDA on the surface of Fe 3 O 4@ Au – PDA nanoparticles was confirmed by the finding that glycine or ethylenediamine could be grafted onto Fe 3 O 4@ Au – PDA nanoparticles through Schiff base reaction. In addition, Fe 3 O 4@ Au – DA nanoparticles, in which DA was substituted for PDA, were prepared using the same method as that for Fe 3 O 4@ Au – PDA nanoparticles and characterized by UV-Vis, TEM and FTIR. The results validated that DA possesses multiple functions of attaching Au seeds as well as acting as both reductant and stabilizing agent, the same functions as those of PDA.

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