Characterization of Fe3O4@CS@NMDP magnetic nanoparticles with core–shell structure prepared by chemical cross-linking method

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.

2016 ◽  
Vol 45 (28) ◽  
pp. 11522-11527 ◽  
Author(s):  
Junqi Li ◽  
Shuang Yao ◽  
Shuyan Song ◽  
Xiao Wang ◽  
Yinghui Wang ◽  
...  

We produce the core@shell structure of PEGylated Yb2O3:Gd@SiO2@CeO2 islands, which exhibit a high-performance dual-modal contrast agent in MRI and CT and excellent catalase mimetic activity.


e-Polymers ◽  
2020 ◽  
Vol 20 (1) ◽  
pp. 254-261
Author(s):  
Mina Ishihara ◽  
Tomofumi Kaeda ◽  
Takashi Sasaki

AbstractIn this study, core–shell particles were prepared as a hybrid material, in which a thin polymer shell was formed on the surface of the SiO2 sphere particles. The core–shell structure was successfully achieved without adding a surfactant via simple free-radical polymerization (soap-free emulsion polymerization) for various monomers of styrene, methyl methacrylate (MMA), and their derivatives. MMA formed thin homogeneous shells of polymer (PMMA) less than 100 nm in thickness with complete surface coverage and a very smooth shell surface. The obtained shell morphology strongly depended on the monomers, which suggests different shell formation mechanisms with respect to the monomers. It was found that the cross-linking monomer 1,4-divinylbenzene tends to promote shell formation, and the cross-linking reaction may stabilize the core–shell structure throughout radical polymerization. It should also be noted that the present method produced a considerable amount of pure polymer besides the core–shell particles. The glass transition temperatures of the obtained polymer shells were higher than those of the corresponding bulk materials. This result suggests strong interactions at the core–shell interface.


2014 ◽  
Vol 602-603 ◽  
pp. 590-593
Author(s):  
Chen Yang Wang ◽  
Bing Bing Fan ◽  
Bing Sun ◽  
Bin Bin Wang ◽  
Wen Li ◽  
...  

SiCp/Cu composites were prepared by vacuum hot-pressing at 770°C for 1.5 h under the pressure of 30MPa. The composites were enhanced by CNTs with different volume fractions from 0 vol. % to 4 vol. %. Three-step approach wrapping process was introduced to prepare composite powders. XRD and SEM techniques were used to characterize the samples. It is found that the core-shell structure composed of SiC core and Cu shell was formed in the composite particles. Optimized volume fraction of CNTs is 1 vol. %. Minimum Porosity and maximum Hardness is about 0.84% and 2.31GPa, respectively. But maximum Flexural strength was measured as 248MPa for samples containing 2 vol. % CNTs. Flexural strength was improved by the bridge effect caused by the increased CNTs.


2010 ◽  
Vol 2010 ◽  
pp. 1-6 ◽  
Author(s):  
O. Hudak ◽  
M. Hudak

There exists nonhomogeneous structure in mechanosynthesized nanoparticles consisting of an ordered core surrounded by the shell. The shell may be structurally and magnetically disordered, or it may be ordered. These nanoparticles are found to be roughly spherical. We formulate the macroscopic model for the description of magnetic properties of nanoparticles with core-shell structure. The case of spheroids oriented in the same direction of polar axes is considered. There exits two coercive fields:HcγandHcψ. They are depending on quantitiesoandx, wherex=V2/(V1−2V2), ando=IF/IS, hereV1is the volume of the nanoparticle, andV2is the volume of the core.IFis the magnetization of the core, andISis the magnetization of the shell. There exists a transition from one type of the coercive field to another, changingxando. We have found qualitative explanation of observed enhancement of coercive field and of itsd-dependence inNiFe2O4nanoparticles.


2015 ◽  
Vol 51 (37) ◽  
pp. 7855-7858 ◽  
Author(s):  
Jiangtao Hu ◽  
Jiaxin Zheng ◽  
Leilei Tian ◽  
Yandong Duan ◽  
Lingpiao Lin ◽  
...  

We synthesized a core–shell structure with graphene as the shell and nano-hollow γ-Fe2O3 as the core through a Kirkendall process at room temperature.


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.


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