Nanocomposite particles for the preparation of advanced nanomaterials

1997 ◽  
Vol 501 ◽  
Author(s):  
P. Somasundaran ◽  
T. Chen
Keyword(s):  
Shell Structure ◽  
Advanced Technology ◽  
Core Shell ◽  
Nanocomposite Particles ◽  
The Core ◽  
Micron Size ◽  
Core Shell Structure ◽  
Shell Particles ◽  
Nano Size ◽  
Core Particles

ABSTRACTNew composites based on nano-size particles provide a promising route to the fabrication of novel materials for advanced technology applications. To produce desired materials, it is important to control the composition and distribution of nanoclusters within the bulk or surface coating of nanostructured materials. Towards this purpose, we have developed a novel method of processing nanocomposite materials utilizing colloidal chemistry techniques to tailor their microstructure. Unique composite aggregates of nanoparticles with a core-shell structure were prepared using a special scheme ofcontrolledpolymer adsorption. Polymers which specifically adsorb on both nano- and micron- size particles are used as tethers to enable desired coating of the later particles with the former and to enhance the cluster integrity. Nanocomposite particles consisting of micron-size alumina or silicon nitride as cores and nano-size alumina, titania, or iron oxide as shell particles have been successfully prepared using this process. The surface charge of the core particles is reversed after the adsorption of polyacrylic acid polymers. This promotes the interaction between the core and the shell particles and therefore nanoparticles added subsequently to the core particle suspension coat on core particles by electrostatic as well as possibly hydrogen bonding bridging mechanisms. Success of the process depends to a large extent on the absence of homoflocculation of nanoparticles and this is achieved by removing all the unadsorbed free polymers from the bulk solution before introducing them to coat on the polymer coated core particles. Coating itself is estimated by monitoring change in the zeta potential of core-shell structure. The coating scheme as well as the characterization of these nanocomposite particles are discussed in detail. This processing scheme provides a simple way for the preparation of both bulk and surface coatings with these engineered nanostructured particles as building blocks.

scholarly journals Effect of Core-Shell Morphology on the Mechanical Properties and Crystallization Behavior of HDPE/HDPE-g-MA/PA6 Ternary Blends

Polymers ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 1040 ◽  
Author(s):  
Lien Zhu ◽  
Haoming Wang ◽  
Meihua Liu ◽  
Zheng Jin ◽  
Kai Zhao
Keyword(s):  
Mechanical Properties ◽  
Shell Structure ◽  
High Density Polyethylene ◽  
Crystallization Behavior ◽  
High Density ◽  
Core Shell ◽  
Ternary Blends ◽  
The Core ◽  
Core Shell Structure ◽  
Shell Particles

In this paper, the high-density polyethylene/maleic anhydride grafted high-density polyethylene/polyamide 6 (HDPE/HDPE-g-MA/PA6) ternary blends were prepared by blend melting. The binary dispersed phase (HDPE-g-MA/PA6) is of a core-shell structure, which is confirmed by the SEM observation and theoretical calculation. The crystallization behavior and mechanical properties of PA6, HDPE-g-MA, HDPE, and their blends were investigated. The crystallization process, crystallization temperature, melting temperature, and crystallinity were studied by differential scanning calorimetry (DSC) testing. The results show that PA6 and HDPE-g-MA interact with each other during crystallizing, and their crystallization behaviors are different when the composition is different. At the same time, the addition of core-shell particles (HDPE-g-MA/PA6) can affect the crystallization behavior of the HDPE matrix. With the addition of the core-shell particles, the comprehensive mechanical properties of HDPE were enhanced, including tensile strength, elastic modulus, and the impact strength. Combined with previous studies, the toughening mechanism of core-shell structure is discussed in detail. The mechanism of the core-shell structure toughening is not only one, but the result of a variety of mechanisms together.

scholarly journals Silica/polymer core–shell particles prepared via soap-free emulsion polymerization

e-Polymers ◽  
2020 ◽  
Vol 20 (1) ◽  
pp. 254-261
Author(s):  
Mina Ishihara ◽  
Tomofumi Kaeda ◽  
Takashi Sasaki
Keyword(s):  
Emulsion Polymerization ◽  
Radical Polymerization ◽  
Shell Structure ◽  
Cross Linking ◽  
Core Shell ◽  
Shell Formation ◽  
The Core ◽  
Core Shell Structure ◽  
Soap Free Emulsion Polymerization ◽  
Shell Particles

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.

The Microemulsion Method for Preparing TiO2 Coated SiO2 Core-Shell Particles

2014 ◽  
Vol 602-603 ◽  
pp. 59-62
Author(s):  
Jing Xie ◽  
Le Fu Mei ◽  
Li Bing Liao ◽  
Guo Cheng Lv ◽  
Zhi Guo Xia ◽  
...  
Keyword(s):  
Shell Structure ◽  
Sintering Temperature ◽  
Phase Changes ◽  
Core Shell ◽  
X Ray Diffraction ◽  
X Ray ◽  
The Core ◽  
Core Shell Structure ◽  
Shell Particles ◽  
Morphology Changes

In this paper, the monodisperse TiO2 particles and TiO2 coated SiO2 core-shell particles were prepared by the method of microemulsion, and the phase and morphology of TiO2 and TiO2 coated SiO2 core-shell structure particles were analyzed by using X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). At the same time, the phase changes and morphology changes of the two different kinds of structural particles as the changes of sintering temperature were compared. The results show that when the TiO2 particles were prepared by the method of microemulsion, the content of anatase TiO2 decreased gradually and the rutile TiO2 increased gradually as the sintering temperature increases from 550 °C to 650 °C; the core-shell particles of TiO2 coated SiO2 prepared were anatase when the sintering temperature increases from 600 °C to 800 °C; all of the particles size were about 1μm, the monodispersity of the particles were optimal and the particles were coated evenly, smoothly. Keywords: TiO2; SiO2; core-shell structure

scholarly journals A SERS Study of Charge Transfer Process in Au Nanorod–MBA@Cu2O Assemblies: Effect of Length to Diameter Ratio of Au Nanorods

Nanomaterials ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 867
Author(s):  
Lin Guo ◽  
Zhu Mao ◽  
Sila Jin ◽  
Lin Zhu ◽  
Junqi Zhao ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Shell Structure ◽  
Shell Structures ◽  
Core Shell ◽  
Absorption Bands ◽  
Au Nanorods ◽  
The Core ◽  
Band Position ◽  
Surface Enhanced Raman ◽  
Core Shell Structure

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.

Construction of MOFs-Shell Porous Materials and Performance Study in Selective Adsorption and Separation of Benzene Pollutants

2021 ◽  
Author(s):  
Yu Qiao ◽  
Na Lv ◽  
Dong Li ◽  
Hongji Li ◽  
Xiangxin Xue ◽  
...  
Keyword(s):  
Porous Materials ◽  
Shell Structure ◽  
Selective Adsorption ◽  
Core Shell ◽  
Architecture Design ◽  
Performance Study ◽  
The Core ◽  
Core Shell Structure ◽  
And Performance ◽  
Sacrificial Agent

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...

Preparation of polyacrylamide microspheres with core–shell structure via surface-initiated atom transfer radical polymerization

RSC Advances ◽  
2016 ◽  
Vol 6 (94) ◽  
pp. 91463-91467 ◽  
Author(s):  
Peng Zhang ◽  
Shixun Bai ◽  
Shilan Chen ◽  
Dandan Li ◽  
Zhenfu Jia ◽  
...  
Keyword(s):  
Atom Transfer Radical Polymerization ◽  
Radical Polymerization ◽  
Shell Structure ◽  
Core Shell ◽  
Atom Transfer ◽  
The Core ◽  
Core Shell Structure

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.

Core–shell stability of nanoparticles plays an important role for overcoming the intestinal mucus and epithelium barrier

2016 ◽  
Vol 4 (35) ◽  
pp. 5831-5841 ◽  
Author(s):  
Min Liu ◽  
Lei Wu ◽  
Xi Zhu ◽  
Wei Shan ◽  
Lian Li ◽  
...  
Keyword(s):  
Shell Structure ◽  
Core Shell ◽  
The Core ◽  
Shell Stability ◽  
Intestinal Mucus ◽  
Core Shell Structure ◽  
The Stability

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

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
Keyword(s):  
Magnetic Nanoparticles ◽  
Shell Structure ◽  
High Performance ◽  
Cross Linking ◽  
Composite Particles ◽  
Core Shell ◽  
The Core ◽  
Targeting Delivery ◽  
Core Shell Structure ◽  
Chemical Cross Linking

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.

The use of galvanic displacement in synthesizing Pt(Cu) catalysts with the core-shell structure

2010 ◽  
Vol 46 (10) ◽  
pp. 1189-1197 ◽  
Author(s):  
B. I. Podlovchenko ◽  
T. D. Gladysheva ◽  
A. Yu. Filatov ◽  
L. V. Yashina
Keyword(s):  
Shell Structure ◽  
Core Shell ◽  
Galvanic Displacement ◽  
The Core ◽  
Cu Catalysts ◽  
Core Shell Structure

Seed-mediated synthesis of bimetallic ruthenium–platinum nanoparticles efficient in cinnamaldehyde selective hydrogenation

2014 ◽  
Vol 43 (24) ◽  
pp. 9283-9295 ◽  
Author(s):  
Xueqiang Qi ◽  
M. Rosa Axet ◽  
Karine Philippot ◽  
Pierre Lecante ◽  
Philippe Serp
Keyword(s):  
Selective Hydrogenation ◽  
Platinum Nanoparticles ◽  
Shell Structure ◽  
Core Shell ◽  
The Core ◽  
Core Shell Structure ◽  
Seed Mediated

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.

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