Synthesis of magnetic silica-based nanocomposites containing Fe₃O₄nanoparticles

Abstract

A new mesostructured hybrid organic-inorganic silica host with internal anchored acetylacetonate groups has been used as a matrix for the growing and organization of Fe 3 O 4 nanoparticles. The approach used consists in the impregnation and the subsequent organic solution-phase decomposition of the molecular precursor Fe[(OC(CH 3 )) 2 CH] 3 into the hybrid silica pores. The magnetic nanocomposite material obtained was fully characterized using transmission electron microscopy (TEM), infrared spectroscopy (IR), nitrogen physisorption, X-ray diffraction techniques and magnetic measurements. These measurements reveal the presence of uniformly sized pure magnetite nanoparticles with a narrow size distribution of 3-4.5 nm exclusively inside the silica matrix. The data demonstrate that the covalent anchoring of the molecular precursor in the silica plays a crucial role in the fabrication of nanocomposites presenting a homogeneous spatial distribution of nanoparticles.

A novel thermal decomposition approach for the synthesis of silica-iron oxide core–shell nanoparticles

“…This mode of bonding has been reported by various authors [53][54][55]. Anchoring of the iron complex is better in the case of activated silica, compared to unactivated silica, due to the removal of organic impurities and the removal of a few Si OH groups that were involved in H-bonding.…”

Synthesis and characterization of nanosized titanium dioxide and silicon dioxide for corrosion resistance applications

“…This is clearly shown in the figure by the black dense part followed by glassy gray colored crystalline SiO 2 particles. The Matsura et al 27 study of high resolution TEM reveals that the iron oxide present in the composite coating is passivating the nano-silica particle and this facet is developing stronger on the sandblasted surface. Figures 7 and 8 show the Bode plots of systems 2 and 4 on mild steel substrate and exposed in 3% sodium chloride solution for different durations.…”

A New Step Towards Solid Base Catalysis: Azidoproazaphosphatranes Immobilized in Nanopores of Mesoporous Silica

“…Anthrone, dimethyl fumarate and N-methylmaleimide were obtained from Alfa Aesar. 3-Hydroxy-2-pyrone was purchased from Tyger Scientific Inc. (3-Iodopropyl)triethoxysilane was prepared by reacting (3-chloropropyl)triethoxysilane with NaI in refluxing acetone for 72 h according to the method described by Matsura et al [41] (3-Azidopropyl)triethoxysilane was synthesized by reacting 3-iodopropyltriethoxysilane with an excess of sodium azide (5 equiv.) in dry DMF at 50 8C for 72 h by adapting a procedure described somewhere.…”