Encapsulation of Magnetic Particles in Metallic Hollow Nanospheres

2001 ◽  
Vol 704 ◽  
Author(s):  
M. Toprak ◽  
D. K. Kim ◽  
M. Mikhailova ◽  
Y. Zhang ◽  
Y. K. Jeong ◽  
...  

AbstractNovel metallic capsules containing magnetite with given size in the sub-micron range have been produced. These nanocapsules are prepared in several steps through a colloidal templating approach. The first step is the synthesis of size-selected SiO2 nanospheres. The second step is coating the SiO2nanospheres by electroless deposition with gold, in order to form a porous gold shell around the silica. Electroless deposition is controlled by the concentration of gold in the coating solution. Subsequently, the core (SiO2) was removed to obtain gold capsules. The final step is the inclusion of magnetite nanoparticles inside these nanocapsules and recoating the capsules with gold in order to have continuous encapsulation. The nanocapsule and core-shell structure have been characterized by TEM and DSC

Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 867
Author(s):  
Lin Guo ◽  
Zhu Mao ◽  
Sila Jin ◽  
Lin Zhu ◽  
Junqi Zhao ◽  
...  

Surface-enhanced Raman scattering (SERS) is a powerful tool in charge transfer (CT) process research. By analyzing the relative intensity of the characteristic bands in the bridging molecules, one can obtain detailed information about the CT between two materials. Herein, we synthesized a series of Au nanorods (NRs) with different length-to-diameter ratios (L/Ds) and used these Au NRs to prepare a series of core–shell structures with the same Cu2O thicknesses to form Au NR–4-mercaptobenzoic acid (MBA)@Cu2O core–shell structures. Surface plasmon resonance (SPR) absorption bands were adjusted by tuning the L/Ds of Au NR cores in these assemblies. SERS spectra of the core-shell structure were obtained under 633 and 785 nm laser excitations, and on the basis of the differences in the relative band strengths of these SERS spectra detected with the as-synthesized assemblies, we calculated the CT degree of the core–shell structure. We explored whether the Cu2O conduction band and valence band position and the SPR absorption band position together affect the CT process in the core–shell structure. In this work, we found that the specific surface area of the Au NRs could influence the CT process in Au NR–MBA@Cu2O core–shell structures, which has rarely been discussed before.


2021 ◽  
Author(s):  
Yu Qiao ◽  
Na Lv ◽  
Dong Li ◽  
Hongji Li ◽  
Xiangxin Xue ◽  
...  

Metastable Cu2O is an attractive material for the architecture design of integrated nanomaterials. In this context, Cu2O was used as the sacrificial agent to form the core-shell structure of Cu2O@HKUST-1...


RSC Advances ◽  
2016 ◽  
Vol 6 (94) ◽  
pp. 91463-91467 ◽  
Author(s):  
Peng Zhang ◽  
Shixun Bai ◽  
Shilan Chen ◽  
Dandan Li ◽  
Zhenfu Jia ◽  
...  

Well defined core–shell microspheres were prepared by surface-initiated atom transfer radical polymerization with pre-crosslinked polyacrylamide as the core and non-crosslinked polyacrylamide as the shell.


2016 ◽  
Vol 4 (35) ◽  
pp. 5831-5841 ◽  
Author(s):  
Min Liu ◽  
Lei Wu ◽  
Xi Zhu ◽  
Wei Shan ◽  
Lian Li ◽  
...  

The stability of the core–shell structure plays an important role in the nanoparticles ability to overcome both the mucus and epithelium absorption barrier.


2018 ◽  
Vol 163 ◽  
pp. 02002 ◽  
Author(s):  
Elzbieta Horszczaruk ◽  
Roman Jedrzejewski ◽  
Jolanta Baranowska ◽  
Ewa Mijowska

The results of investigation of the cement composites modified with 5% of silica-magnetite nanostructures of the core-shell type are presented in the paper. The nanoindentation method employing three-sided pyramidal Berkovich indenter was used in the research. The mechanical properties and microstructure of the modified cement composites were evaluated on the basis of the values of hardness and indentation modulus measured inside the cement matrix and in the aggregate-paste interfacial zone. The results were compared with those obtained for the reference composites without nanostructures. The positive influence of the presence of silica-magnetite nanoparticles on the tested properties was found out.


2017 ◽  
Vol 10 (05) ◽  
pp. 1750056 ◽  
Author(s):  
Huiping Shao ◽  
Jiangcong Qi ◽  
Tao Lin ◽  
Yuling Zhou ◽  
Fucheng Yu

The core–shell structure composite magnetic nanoparticles (NPs), Fe3O4@chitosan@nimodipine (Fe3O4@CS@NMDP), were successfully synthesized by a chemical cross-linking method in this paper. NMDP is widely used for cardiovascular and cerebrovascular disease prevention and treatment, while CS is of biocompatibility. The composite particles were characterized by an X-ray diffractometer (XRD), a Fourier transform infrared spectroscopy (FT-IR), a transmission electron microscopy (TEM), a vibrating sample magnetometers (VSM) and a high performance liquid chromatography (HPLC). The results show that the size of the core–shell structure composite particles is ranging from 12[Formula: see text]nm to 20[Formula: see text]nm and the coating thickness of NMDP is about 2[Formula: see text]nm. The saturation magnetization of core–shell composite NPs is 46.7[Formula: see text]emu/g, which indicates a good potential application for treating cancer by magnetic target delivery. The release percentage of the NMDP can reach 57.6% in a short time of 20[Formula: see text]min in the PBS, and to 100% in a time of 60[Formula: see text]min, which indicates the availability of Fe3O4@CS@NMDP composite NPs for targeting delivery treatment.


2010 ◽  
Vol 46 (10) ◽  
pp. 1189-1197 ◽  
Author(s):  
B. I. Podlovchenko ◽  
T. D. Gladysheva ◽  
A. Yu. Filatov ◽  
L. V. Yashina

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Su-Ryeon Yun ◽  
Gyeong-Ok Kim ◽  
Chan Woo Lee ◽  
Nam-Ju Jo ◽  
Yongku Kang ◽  
...  

Polyaniline (Pani) and polypyrrole (Ppy) half hollow spheres with different shell thicknesses were successfully synthesized by three steps process using polystyrene (PS) as the core. The PS core was synthesized by emulsion polymerization. Aniline and pyrrole monomers were polymerized on the surface of the PS core. The shells of Pani and Ppy were fabricated by adding different amounts of aniline and pyrrole monomers. PS cores were dissolved and removed from the core shell structure by solvent extraction. The thicknesses of the Pani and Ppy half hollow spheres were observed by FE-SEM and FE-TEM. The chemical structures of the Pani and Ppy half hollow spheres were characterized by FT-IR spectroscopy and UV-Vis spectroscopy. The shell thicknesses of the Pani half hollow spheres were 30.2, 38.0, 42.2, 48.2, and 52.4 nm, while the shell thicknesses of the Ppy half hollow spheres were 16.0, 22.0, 27.0, and 34.0 nm. The shell thicknesses of Pani and Ppy half hollow spheres linearly increased as the amount of the monomer increased. Therefore, the shell thickness of the Pani and Ppy half hollow spheres can be controlled in these ranges.


2014 ◽  
Vol 43 (24) ◽  
pp. 9283-9295 ◽  
Author(s):  
Xueqiang Qi ◽  
M. Rosa Axet ◽  
Karine Philippot ◽  
Pierre Lecante ◽  
Philippe Serp

The two-step synthesis of small ruthenium–platinum nanoparticles leads to the formation of a core–shell structure. The catalytic results provide supplementary evidence of the core–shell structure.


2017 ◽  
Vol 31 (33) ◽  
pp. 1750307 ◽  
Author(s):  
Ersin Kantar

In this study, we examine by comparing the dynamic magnetic and hysteretic properties of Ising-type endohedral fullerene (EF) with various dopant magnetic particles confined within a spherical cage. The model of EF X@C[Formula: see text] with X = spin-1/2, spin-1 and spin-3/2 is proposed to study the effect of the nature of core particle on the magnetic properties. The results were obtained by mean-field theory as well as Glauber-type stochastic dynamics, and focused on the response of thermal and hysteretic behaviors of systems. The system exhibits second- and first-order phase transitions. In three different core cases, the system also exhibits type-II superconductivity behavior with a dynamic hysteresis curves of the core. All results display magnetic properties of the EF which strongly depend on the nature of core particle. Moreover, core particle and core/shell (C–S) interaction are proposed as the basic factors affecting the magnetic properties of EF system.


Sign in / Sign up

Export Citation Format

Share Document