The role of diffusion behavior on the formation and evolution of the core‐shell structure in BaTiO 3 ‐based ceramics

2019 ◽  
Vol 103 (1) ◽  
pp. 304-314 ◽  
Author(s):  
Cheng Chen ◽  
Hua Hao ◽  
Jingjing Cui ◽  
Cong Yu ◽  
Yingfei Tang ◽  
...  
2021 ◽  
Author(s):  
Dilip Sao ◽  
Probodh Kumar Kuiri ◽  
Rajib Nath

Abstract Metal-polymer nanocomposite materials have interesting physical, chemical, and optical properties which were highly utilized in electronic, optical,and biomedical applications. Here, we have experimentally and theoretically studied the crucial role of polymer Polyvinylpyrrolidone (PVP) on the localized surface plasmon resonance (LSPR) spectra of silver (Ag) nanoparticles (NPs). In this work, we have synthesized PVP stabilized Ag NPs in Ethelene Glycol (EG) medium and observed a large blueshift (20 nm)of LSPR peak and tunable plasmonic properties of PVP coated Ag NPs by only varying the concentration of PVP. A reduction of Ag NP size from 13 nm to 5 nm with the increase in PVP concentration from 0.125 mM to 3 mM is seen. We found that the observed large blueshift of the LSPR bands with the varying in PVP concentration is not just due to the reduced Ag NP size but due to the combined effect of thickness of the PVP shell and radius of the Ag NP core. The polymer PVP used in the synthesis process of Ag NPs plays role of a surface modifier and forms a protective shell/layer surrounding the (core) particle. This is supported by the theoretical optical absorption data obtained from a modified effective medium theory. To accommodate such a large blueshift of the LSPR bands we have considered the Ag-PVP core-shell structure. The LSPR peak shift in the core-shell nanostructure is well accommodated by varying the effective shell thickness of PVP while taking the core size of Ag NPs as measured experimentally for each case. This clearly indicates that the observed large blueshift of SPR band of Ag NPs cannot be justified by considering the decrease in Ag NP size alone. It is also confirmed that the shell thickness of PVP plays a crucial role in explaining the blueshift of the SPR band of Ag NPs. This study can help to understand the optical response especially plasmonic properties of other metal NPs coated with organic polymers.


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.


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

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.


Soft Matter ◽  
2015 ◽  
Vol 11 (19) ◽  
pp. 3936-3945 ◽  
Author(s):  
Sang Min Lee ◽  
Young Chan Bae

Schematic depiction of a core–shell structure composed of the PMMA core and the PHEMA shell, and the influence of three co-solvents on the volume transition temperature of the core–shell gels in 1-propanol solution.


2020 ◽  
Vol 90 ◽  
pp. 106767
Author(s):  
Tao Peng ◽  
Fei Lv ◽  
Zhou Gong ◽  
Liming Cao ◽  
Xuesong Yan ◽  
...  

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