scholarly journals Ceria/silicon carbide core–shell materials prepared by miniemulsion technique

2011 ◽  
Vol 2 ◽  
pp. 638-644 ◽  
Author(s):  
Lars Borchardt ◽  
Martin Oschatz ◽  
Robert Frind ◽  
Emanuel Kockrick ◽  
Martin R Lohe ◽  
...  
Keyword(s):  
Cross Correlation ◽  
Methane Combustion ◽  
Correlation Spectroscopy ◽  
Core Shell ◽  
Particle Sizes ◽  
Temperature Programmed Oxidation ◽  
Preparation Conditions ◽  
Temperature Programmed ◽  
Shell Particles ◽  
First Time

For the first time we present the synthesis of CeO2/Si(O)C core–shell particles prepared by the miniemulsion technique. The Si(O)C core was obtained by means of a polycarbosilane precursor (SMP10), which was subsequently functionalized with ceria and pyrolyzed to the ceramic. The size of these particles could easily be adjusted by varying the surfactants and the surfactant concentration, or by the addition of comonomers. Hence particle sizes ranged from 100 to 1000 nm, tunable by the preparation conditions. All materials were characterized by photon cross correlation spectroscopy, scanning electron microscopy and elemental mapping investigations. Furthermore, first catalytic tests were carried out by temperature programmed oxidation (TPO) of methane, and the activity of this material in lowering the onset temperature of methane combustion by 262 K was documented.

Novel conductive core–shell particles of elastomeric nanoparticles coated with polypyrrole

RSC Advances ◽  
2015 ◽  
Vol 5 (120) ◽  
pp. 98904-98909 ◽  
Author(s):  
Jiangru Zhang ◽  
Guicun Qi ◽  
Xiang Wang ◽  
Binghai Li ◽  
Zhihai Song ◽  
...  
Keyword(s):  
Shell Structure ◽  
Oxidative Polymerization ◽  
Core Shell ◽  
Conductive Particle ◽  
Core Shell Structure ◽  
Shell Particles ◽  
First Time

For the first time, an ultrafine conductive particle with core–shell structure, acrylonitrile-butadiene elastomeric nanoparticle (NBR-ENP) coated with polypyrrole (PPy), was prepared by in situ oxidative polymerization.

scholarly journals Catalytic Performance of a Magnetic Core-Shell Iron(II) C-Scorpionate under Unconventional Oxidation Conditions

Nanomaterials ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 2111
Author(s):  
Inês A. S. Matias ◽  
Ana P. C. Ribeiro ◽  
Ana M. Ferraria ◽  
Ana M. Botelho do Rego ◽  
Luísa M. D. R. S. Martins
Keyword(s):  
Alternative Energy ◽  
Alcohol Oxidation ◽  
Catalytic Performance ◽  
Magnetic Core ◽  
Core Shell ◽  
Secondary Alcohols ◽  
Alternative Energy Sources ◽  
Metallic Complex ◽  
Shell Particles ◽  
First Time

For the first time, herein is reported the use of a magnetic core-shell support for a C-scorpionate metallic complex. The prepared hybrid material, that consists on the C-scorpionate iron(II) complex [FeCl2{κ3-HC(pz)3}] (pz, pyrazolyl) immobilized at magnetic core-shell particles (Fe3O4/TiO2), was tested as catalyst for the oxidation of secondary alcohols using the model substrate 1-phenylethanol. Moreover, the application of alternative energy sources (e.g., ultrasounds, microwaves, mechanical or thermal) for the peroxidative alcohol oxidation using the magnetic heterogenized iron(II) scorpionate led to different/unusual outcomes that are presented and discussed.

Spatio-temporally Resolved Investigation of Surface Charges, N2(A3∑u+) Metastables and Discharge Development in Barrier Discharges

2012 ◽  
Vol 15 (2) ◽  
Author(s):  
Marc Bogaczyk ◽  
Sebastian Nemschokmichal ◽  
Anton Zagoskin ◽  
Goran B. Sretenović ◽  
Jürgen Meichsner ◽  
...  
Keyword(s):  
Cross Correlation ◽  
Ccd Camera ◽  
Diagnostic Techniques ◽  
Correlation Spectroscopy ◽  
Pockels Effect ◽  
Surface Charges ◽  
Discharge Cell ◽  
Barrier Discharges ◽  
First Time

AbstractTo study the interaction of an insulated surface with the volume of a barrier discharge, a discharge cell was developed to combine for the first time three diagnostic techniques in ONE discharge cell configuration. The discharge development was investigated by the cross-correlation-spectroscopy (CCS), the surface charge measurement on the dielectrics by the application of the optoelectronic Pockels effect in combination with a CCD camera, and the determination of the metastable N

scholarly journals Dynamics of soft nanoparticle suspensions at hard X-ray FEL sources below the radiation-damage threshold

IUCrJ ◽  
2018 ◽  
Vol 5 (6) ◽  
pp. 801-807 ◽  
Author(s):  
Felix Lehmkühler ◽  
Joana Valerio ◽  
Dina Sheyfer ◽  
Wojciech Roseker ◽  
Martin A. Schroer ◽  
...  
Keyword(s):  
Radiation Damage ◽  
Soft Matter ◽  
Damage Threshold ◽  
Correlation Spectroscopy ◽  
Time Range ◽  
Single Shot ◽  
X Ray ◽  
Nanoparticle Suspensions ◽  
Shell Particles ◽  
First Time

The application of X-ray photon correlation spectroscopy (XPCS) at free-electron laser (FEL) facilities enables, for the first time, the study of dynamics on a (sub-)nanometre scale in an unreached time range between femtoseconds and seconds. For soft-matter materials, radiation damage is a major limitation when going beyond single-shot applications. Here, an XPCS study is presented at a hard X-ray FEL on radiation-sensitive polymeric poly(N-isopropylacrylamide) (PNIPAM) nanoparticles. The dynamics of aqueous suspensions of densely packed silica-PNIPAM core-shell particles and a PNIPAM nanogel below the radiation-damage threshold are determined. The XPCS data indicate non-diffusive behaviour, suggesting ballistic and stress-dominated heterogeneous particle motions. These results demonstrate the feasibility of XPCS experiments on radiation-sensitive soft-matter materials at FEL sources and pave the way for future applications at MHz repetition rates as well as ultrafast modes using split-pulse devices.

scholarly journals Influence of Mie scattering on nanoparticles with different particle sizes and shapes: Photometry and analytical ultracentrifugation with absorption optics

2005 ◽  
Vol 70 (3) ◽  
pp. 361-369 ◽  
Author(s):  
M.D. Lechner
Keyword(s):  
Analytical Ultracentrifugation ◽  
Mie Scattering ◽  
Precise Determination ◽  
Core Shell ◽  
Particle Sizes ◽  
Wide Range ◽  
Photometric Measurements ◽  
Shell Particles ◽  
Reliable Methods

Nanoparticles are used in large quantities for very different applications. A precise determination of the diameter and the particle size distribution which is responsible for the application properties is therefore essential. Reliable methods for measuring the above mentioned quantities are photometric measurements and analytical ultracentrifugation with an UV optics detector. Both methods are ruled by the Mie effect, that is scattering and absorption of the particles as function of the diameter, the wavelength, and the shape of the particles. The extinction coefficients ?=?/c for spheres, rods, and core shell particles have been calculated and plotted over a wide range of the size parameter ?d/?. Two examples for multimodal latex particles and core shell particles have been given and demonstrate the applicability of the method.

Fabrication of a core–shell–shell particle with a quarter-wave thick shell and its optical properties

RSC Advances ◽  
2014 ◽  
Vol 4 (61) ◽  
pp. 32293-32297 ◽  
Author(s):  
Hiroki Shibata ◽  
Kenji Imakita ◽  
Minoru Fujii
Keyword(s):  
Optical Properties ◽  
Core Shell ◽  
Thick Shell ◽  
Chemical Solution ◽  
Shell Particle ◽  
Solution Processes ◽  
Quarter Wave ◽  
Shell Particles ◽  
Thick Shells ◽  
First Time

In the present work, core–shell–shell particles with quarter-wave thick shells have been synthesized using chemical solution processes for the first time and the optical properties are discussed both theoretically and experimentally.

Magnetic Properties of Fe3O4/CoFe2O4 Composite Nanoparticles with Core/Shell Architecture

2020 ◽  
Vol 65 (10) ◽  
pp. 904
Author(s):  
V. O. Zamorskyi ◽  
Ya. M. Lytvynenko ◽  
A. M. Pogorily ◽  
A. I. Tovstolytkin ◽  
S. O. Solopan ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Spinel Ferrite ◽  
Composite Nanoparticles ◽  
Core Shell ◽  
Cofe2o4 Nanoparticles ◽  
Core Diameter ◽  
The Core ◽  
Shell Particles ◽  
Interface Parameters ◽  
Shell Composite

Magnetic properties of the sets of Fe3O4(core)/CoFe2O4(shell) composite nanoparticles with a core diameter of about 6.3 nm and various shell thicknesses (0, 1.0, and 2.5 nm), as well as the mixtures of Fe3O4 and CoFe2O4 nanoparticles taken in the ratios corresponding to the core/shell material contents in the former case, have been studied. The results of magnetic research showed that the coating of magnetic nanoparticles with a shell gives rise to the appearance of two simultaneous effects: the modification of the core/shell interface parameters and the parameter change in both the nanoparticle’s core and shell themselves. As a result, the core/shell particles acquire new characteristics that are inherent neither to Fe3O4 nor to CoFe2O4. The obtained results open the way to the optimization and adaptation of the parameters of the core/shell spinel-ferrite-based nanoparticles for their application in various technological and biomedical domains.

Non-Plasmonic SERS with Silicon: Is It Really Safe? New Insights into Opto-Thermics of Core/Shell Microbeads

2018 ◽  
Author(s):  
Nicolò Bontempi ◽  
Irene Vassalini ◽  
Stefano Danesi ◽  
Matteo Ferroni ◽  
Paolo Colombi ◽  
...  
Keyword(s):  
Critical Role ◽  
Raman Laser ◽  
Core Shell ◽  
Thermal Coupling ◽  
Melting Points ◽  
Experimental Proof ◽  
Weakly Coupled ◽  
Light Management ◽  
Laser Sources ◽  
First Time

<p>Here we investigate for the first time the opto-thermal behavior of SiO<sub>2</sub>/Si core/shell microbeads (Si-rex) irradiated with three common Raman laser sources (lambda=532, 633, 785 nm) under real working conditions. We obtained an experimental proof of the critical role played by bead size and aggregation in heat and light management, demonstrating that in the case of strong opto-thermal coupling the temperature can exceed that of the melting points of both core and shell components. In addition, we also show that weakly coupled beads can be utilized as stable substrates for plasmon-free SERS experiments.</p>

scholarly journals Variably Sized and Multi-Colored Silica-Nanoparticles Characterized by Fluorescence Correlation Methods for Cellular Dynamics

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 19
Author(s):  
Chan-Gi Pack ◽  
Bjorn Paulson ◽  
Yeonhee Shin ◽  
Min Kyo Jung ◽  
Jun Sung Kim ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Correlation Spectroscopy ◽  
Cell Uptake ◽  
Core Shell ◽  
Therapeutic Effects ◽  
Ferrite Core ◽  
Shell Nanoparticles ◽  
Fluorescence Correlation ◽  
Correlation Methods

Controlling the uptake of nanoparticles into cells so as to balance therapeutic effects with toxicity is an essential unsolved problem in the development of nanomedicine technologies. From this point of view, it is useful to use standard nanoparticles to quantitatively evaluate the physical properties of the nanoparticles in solution and in cells, and to analyze the intracellular dynamic motion and distribution of these nanoparticles at a single-particle level. In this study, standard nanoparticles are developed based on a variant silica-based nanoparticle incorporating fluorescein isothiocyanate (FITC) or/and rhodamine B isothiocyanate (RITC) with a variety of accessible diameters and a matching fluorescent cobalt ferrite core-shell structure (Fe2O4/SiO2). The physical and optical properties of the nanoparticles in vitro are fully evaluated with the complementary methods of dynamic light scattering, electron microscopy, and two fluorescence correlation methods. In addition, cell uptake of dual-colored and core/shell nanoparticles via endocytosis in live HeLa cells is detected by fluorescence correlation spectroscopy and electron microscopy, indicating the suitability of the nanoparticles as standards for further studies of intracellular dynamics with multi-modal methods.

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