scholarly journals Preparation and Characterization of Magnetite – Silica Core – Shell Nanoparticles

2021 ◽  
Vol 15 ◽  
pp. 1457-1463
Author(s):  
S. N. Vakhneev ◽  
Minggong Sha
Keyword(s):  
Magnetite Nanoparticles ◽  
Biomedical Applications ◽  
Core Shell ◽  
Amino Groups ◽  
Absorption Bands ◽  
Shell Nanoparticles ◽  
Oh Groups ◽  
Silica Core ◽  
Core Shell Nanoparticles

In this study, two types of ligands were introduced onto the surface of magnetite nanoparticles by hydrolysis and condensation of organosilicon reagents: organosilane-tetraethoxysilane (TEOS) and aminoorganosilane - aminopropyltriethoxysilane (APTES). It is shown that coatings based on SiO2 solve a double problem: first, they prevent the aggregation of nanoparticles and the oxidation of magnetite; secondly, they allow the surface to be modified with various specific ligands for biomedical applications due to terminal groups. It was shown, that after the modification of TEOS and APTES (in argon and in air), the Fe3O4 content decreases to 66, 42, and 36%, respectively. The formation of a silicon framework on the magnetite surface due to Fe-O-Si and Si-O-Si bonds was determined by IR spectroscopy. The identification of surface amino groups is complicated due to the superposition of absorption bands of NH2- and OH-groups. This opens new prospective for creation of tailored nanocomposites containing magnetite nanoparticles. These materials can be further used as sorbents for various applications.

scholarly journals Linear β-amino alcohol catalyst anchored on functionalized magnetite nanoparticles for enantioselective addition of dialkylzinc to aromatic aldehydes

RSC Advances ◽  
2020 ◽  
Vol 10 (50) ◽  
pp. 29688-29695
Author(s):  
Carla Sappino ◽  
Ludovica Primitivo ◽  
Martina De Angelis ◽  
Francesco Righi ◽  
Federica Di Pietro ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Magnetite Nanoparticles ◽  
Amino Alcohol ◽  
Aromatic Aldehydes ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
Silica Core ◽  
Enantioselective Addition ◽  
Core Shell Nanoparticles

The catalytic activity of a linear β-amino alcohol ligand anchored on functionalized magnetite/silica core–shell nanoparticles has been evaluated in the addition of dialkylzinc to aldehydes leading to promising results.

scholarly journals Structural and Spectroscopic Characterization of PM 597 Dye-Silica Core-Shell Nanoparticles

2015 ◽  
Vol 2015 ◽  
pp. 1-7
Author(s):  
Tahani R. Al-Biladi ◽  
A. S. Al Dwayyan ◽  
M. Naziruddin Khan ◽  
Saif M. H. Qaid ◽  
Khalid Al Zahrani
Keyword(s):  
Emission Spectra ◽  
Spectroscopic Characterization ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
Silica Core ◽  
Shell Particles ◽  
Average Size ◽  
Core Shell Nanoparticles ◽  
20 Nm

Nanostructured fluorescent pyrromethene (PM) doped-silica core-shell particles were successfully prepared by Stöber process. The average size of the particles was in the range of 10–20 nm measured by TEM micrograph. The atomic structure and morphology of PM 597/SiO2core/shell nanoparticles were studied by AFM and SEM, respectively. Absorption and emission spectra of the PM 597/SiO2core/shell nanoparticles under the UV irradiation were studied and not significantly influenced at the position of peaks. Finally, amplified spontaneous emission (ASE) and photobleaching of dye were examined and found no significant influence on the peaks of PM dye due to the formation of smaller sizes of PM 597/SiO2core/shell nanoparticles. The observed PM 597/SiO2core/shell nanoparticles were different in shapes with smaller size distribution and highly luminescent. Majority of nanoparticles were roughly spherical with many of them aggregated. The less photobleaching of dye core may be due to the protection of pumped energy by SiO2shell and restricts the leakage of dye.

β-Cyclodextrin conjugated magnetic, fluorescent silica core–shell nanoparticles for biomedical applications

2013 ◽  
Vol 95 (1) ◽  
pp. 449-457 ◽  
Author(s):  
Abu Zayed Md. Badruddoza ◽  
Md. Taifur Rahman ◽  
Sudipa Ghosh ◽  
Md. Zakir Hossain ◽  
Jizhong Shi ◽  
...  
Keyword(s):  
Biomedical Applications ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
Silica Core ◽  
Core Shell Nanoparticles

Preparation and characterization of cationic pH-sensitive SiO2/polymer core-shell nanoparticles with amino groups in the shell

2014 ◽  
Vol 292 (10) ◽  
pp. 2611-2620 ◽  
Author(s):  
Yang Hu ◽  
Guanzhi Cheng ◽  
Jishuai Wang ◽  
Guoqiang Jiang ◽  
Chengyou Kan
Keyword(s):  
Ph Sensitive ◽  
Core Shell ◽  
Amino Groups ◽  
Shell Nanoparticles ◽  
Core Shell Nanoparticles

Synthesis and Characterization of Silylated Kaolinite/Silica Core–Shell Nanoparticles

2011 ◽  
Vol 105-107 ◽  
pp. 1760-1763
Author(s):  
Qian Zhang ◽  
Bai Mei Zhang
Keyword(s):  
Sol Gel ◽  
Core Shell ◽  
Silane Treatment ◽  
Shell Nanoparticles ◽  
Ultrafine Silica ◽  
Gel Technique ◽  
Silica Core ◽  
Kaolinite Surface ◽  
Core Shell Nanoparticles

Studies were conducted on the production of silane modified kaolinite/silica core-shell nanoparticles (SMKS). The SMKS nanoparticles were prepared via the sol–gel technique using tetraethyl oxysilane (TEOS) as the precursor to form silica shells on the surface of kaolinite particles followed with silane treatment. TEM of the unmodified kaolin (ORK) and SMKS revealed that a layer of ultrafine silica particles were deposited on the kaolinite surface to form a new kind of core–shell structure particles.

scholarly journals Structural and chemical characterization of MoO2/MoS2 triple-hybrid materials using electron microscopy in up to three dimensions

2021 ◽  
Author(s):  
Anna Frank ◽  
Thomas Gänsler ◽  
Stefan Hieke ◽  
Simon Fleischmann ◽  
Samantha Husmann ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Chemical Characterization ◽  
Three Dimensions ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
Microscopy Investigation ◽  
Electron Microscopy Investigation ◽  
Carbon Nanotube Network ◽  
Core Shell Nanoparticles

This work presents the synthesis of MoO2/MoS2 core/shell nanoparticles within a carbon nanotube network and their detailed electron microscopy investigation in up to three dimensions. The triple-hybrid core/shell material was...

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