scholarly journals Low temperature superparamagnetic nanocomposites obtained by Fe(acac)3-SiO2-PVA hybrid xerogel thermolysis

2016 ◽  
Vol 10 (4) ◽  
pp. 265-275 ◽  
Author(s):  
Catalin Ianasi ◽  
Otilia Costisor ◽  
Ana-Maria Putz ◽  
Radu Lazau ◽  
Adina Negrea ◽  
...  
Keyword(s):  
Iron Oxide ◽  
Spinel Phase ◽  
Sol Gel ◽  
Average Crystallite Size ◽  
Weight Percent ◽  
Silica Xerogel ◽  
Nominal Composition ◽  
One Pot ◽  
Calcination Temperatures ◽  
Sol Gel Synthesis

Fe(acac)3/silica/PVA hybrid xerogel nanocomposite was obtained by one pot acid catalysed sol-gel synthesis using the homogeneous mixture of iron(III) acetylacetonate (Fe(acac)3), tetraethylorthosilicate (TEOS), and polyvinyl alcohol (PVA). Nominal composition ratio of iron oxide/silica was 15/85 (weight percent). Nitric acid was used as catalyst. Another sample of Fe(acac)3/silica xerogel without PVA addition was prepared in the similar processing conditions. Based on thermal analysis studies, the thermal behaviour of both xerogel samples was unveiled and it allowed choosing the optimal calcination temperatures in order to obtain iron oxide silica magnetic nanocomposite samples. The two xerogel (with and without PVA) samples were thermally treated, in air, at 220, 260 and 300?C and characterized by different techniques. XRD investigations revealed phase composition evolution with calcination temperature, from cubic spinel phase (maghemite) to hexagonal stable hematite containing nanocomposite of 10-20 nm average crystallite size. These findings were confirmed by M?ssbauer spectroscopy. Up to 300?C, the surface area and total pores volume increased with temperature for all samples. By calcination at the same temperature, the hybrid xerogel containing PVA resulted in significantly higher magnetization and free volume values in comparison with the sample without PVA.

scholarly journals Sol-Gel Synthesis, Structure, Morphology and Magnetic Properties of Ni0.6Mn0.4Fe2O4 Nanoparticles Embedded in SiO2 Matrix

Nanomaterials ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3455
Author(s):  
Thomas Dippong ◽  
Erika Andrea Levei ◽  
Iosif Grigore Deac ◽  
Ioan Petean ◽  
Gheorghe Borodi ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Sol Gel ◽  
Average Crystallite Size ◽  
Secondary Phase ◽  
Ferromagnetic Behavior ◽  
Sio2 Matrix ◽  
Calcination Temperatures ◽  
Structure Morphology ◽  
A Minor ◽  
Sol Gel Synthesis

The structure, morphology and magnetic properties of (Ni0.6Mn0.4Fe2O4)α(SiO2)100−α (α = 0–100%) nanocomposites (NCs) produced by sol-gel synthesis were investigated using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), atomic force microscopy (AFM) and vibrating sample magnetometry (VSM). At low calcination temperatures (300 °C), poorly crystallized Ni0.6Mn0.4Fe2O4, while at high calcination temperatures, well-crystallized Ni0.6Mn0.4Fe2O4 was obtained along with α-Fe2O3, quartz, cristobalite or iron silicate secondary phase, depending on the Ni0.6Mn0.4Fe2O4 content in the NCs. The average crystallite size increases from 2.6 to 74.5 nm with the increase of calcination temperature and ferrite content embedded in the SiO2 matrix. The saturation magnetization (Ms) enhances from 2.5 to 80.5 emu/g, the remanent magnetization (MR) from 0.68 to 12.6 emu/g and the coercive field (HC) from 126 to 260 Oe with increasing of Ni0.6Mn0.4Fe2O4 content in the NCs. The SiO2 matrix has a diamagnetic behavior with a minor ferromagnetic fraction, Ni0.6Mn0.4Fe2O4 embedded in SiO2 matrix displays superparamagnetic behavior, while unembedded Ni0.6Mn0.4Fe2O4 has a high-quality ferromagnetic behavior.

scholarly journals One pot transparent sol-gel synthesis of TiO2 nanospheres with pristine anatase phase and their physicochemical characteristics

2016 ◽  
Vol 2 (1) ◽  
pp. 23-30 ◽  
Author(s):  
O.S.N. Ghosh ◽  
◽  
S. Gayathri ◽  
D. Alagarasan ◽  
K.V.P. Kumar ◽  
...  
Keyword(s):  
Anatase Phase ◽  
Sol Gel ◽  
Physicochemical Characteristics ◽  
One Pot ◽  
Sol Gel Synthesis

scholarly journals A mesostructured hybrid CTA–silica carrier for curcumin delivery

2020 ◽  
Vol 96 (1) ◽  
pp. 236-246
Author(s):  
Marta Gallo ◽  
Fabio Giudice ◽  
Mauro Banchero ◽  
Silvia Ronchetti ◽  
Luigi Manna ◽  
...  
Keyword(s):  
Water Solubility ◽  
Uv Spectroscopy ◽  
Sol Gel ◽  
Topical Administration ◽  
Release Mechanism ◽  
Active Principle ◽  
One Pot ◽  
Drug Release Mechanism ◽  
Sol Gel Synthesis ◽  
First Time

Abstract Curcumin is a natural active principle with antioxidant, antibacterial and anti-inflammatory properties. Its use is limited by a low water solubility and fast degradation rate, which hinder its bioavailability. To overcome this problem, curcumin can be delivered through a carrier, which protects the drug molecule and enhances its pharmacological effects. The present work proposes a simple one-pot sol–gel synthesis to obtain a hybrid carrier for curcumin delivery. The hybrid consists of a mesostructured matrix of amorphous silica, which stabilizes the carrier, and hexadecyltrimethylammonium (CTA), a surfactant where curcumin is dissolved to increase its water solubility. The carrier was characterized in terms of morphology (FESEM), physicochemical properties (XRD, FTIR, UV spectroscopy) and release capability in pseudo-physiological solutions. Results show that curcumin molecules were entrapped, for the first time, in a silica-surfactant mesostructured hybrid carrier. The hybrid carrier successfully released curcumin in artificial sweat and in a phosphate buffer saline solution, so confirming its efficacy in increasing curcumin water solubility. The proposed drug release mechanism relies on the degradation of the carrier, which involves the concurrent release of silicon. This suggests strong potentialities for topical administration applications, since curcumin is effective against many dermal diseases while silicon is beneficial to the skin.

scholarly journals Self-assembly of iron oxide precursor micelles driven by magnetic stirring time in sol–gel coatings

RSC Advances ◽  
2019 ◽  
Vol 9 (31) ◽  
pp. 17571-17580 ◽  
Author(s):  
J. López-Sánchez ◽  
A. Serrano ◽  
A. del Campo ◽  
M. Abuín ◽  
E. Salas-Colera ◽  
...  
Keyword(s):  
Iron Oxide ◽  
Self Assembly ◽  
Sol Gel ◽  
Oxide Precursor ◽  
Magnetic Stirring ◽  
Stirring Time ◽  
Self Assembled ◽  
Sol Gel Synthesis

Sol–gel synthesis of self-assembled iron oxide precursor micelles.

Eu3+-doped CdS nanocrystals in SiO2matrices: one-pot sol–gel synthesis and optical characterization

2006 ◽  
Vol 16 (47) ◽  
pp. 4612-4618 ◽  
Author(s):  
Beatriz Julián ◽  
José Planelles ◽  
Eloisa Cordoncillo ◽  
Purificación Escribano ◽  
Patrick Aschehoug ◽  
...  
Keyword(s):  
Sol Gel ◽  
Optical Characterization ◽  
One Pot ◽  
Cds Nanocrystals ◽  
Sol Gel Synthesis

One-pot sol-gel synthesis of Si/C yolk-shell anodes for high performance lithium-ion batteries

2020 ◽  
Vol 835 ◽  
pp. 155135 ◽  
Author(s):  
Wei Zhang ◽  
Jianjiang Li ◽  
Peng Guan ◽  
Chunxiao Lv ◽  
Chao Yang ◽  
...  
Keyword(s):  
Lithium Ion Batteries ◽  
High Performance ◽  
Sol Gel ◽  
Lithium Ion ◽  
One Pot ◽  
Sol Gel Synthesis

One-pot sol–gel synthesis of Ni/TiO2 catalysts for methane decomposition into COx free hydrogen and multiwalled carbon nanotubes

2017 ◽  
Vol 42 (26) ◽  
pp. 16495-16513 ◽  
Author(s):  
Manoj Pudukudy ◽  
Zahira Yaakob ◽  
Abudukeremu Kadier ◽  
Mohd Sobri Takriff ◽  
Nik Suhaimi Mat Hassan
Keyword(s):  
Carbon Nanotubes ◽  
Multiwalled Carbon Nanotubes ◽  
Sol Gel ◽  
Methane Decomposition ◽  
Multiwalled Carbon ◽  
One Pot ◽  
Free Hydrogen ◽  
Sol Gel Synthesis

Fabrication of transparent iron‐oxide films by means of sol‐gel synthesis (abstract)

1988 ◽  
Vol 64 (10) ◽  
pp. 5452-5452 ◽  
Author(s):  
K. Yamaguchi ◽  
T. Fujii ◽  
S. Kuranouchi ◽  
A. Kaneko
Keyword(s):  
Iron Oxide ◽  
Sol Gel ◽  
Oxide Films ◽  
Iron Oxide Films ◽  
Sol Gel Synthesis

Sol-Gel Synthesis and Preliminary Characterizations of Novel Silica Hybrid Xerogels

2013 ◽  
Vol 594-595 ◽  
pp. 1009-1014
Author(s):  
S.A. Syed Nuzul Fadzli ◽  
S. Roslinda ◽  
Z. Firuz
Keyword(s):  
Sodium Alginate ◽  
Calcium Oxide ◽  
Sol Gel ◽  
Silica Xerogel ◽  
Particle Sizes ◽  
Mesoporous Composite ◽  
Hybrid Silica ◽  
Hybrid Xerogels ◽  
Mild Temperature ◽  
Sol Gel Synthesis

Hybrid silica xerogel mesoporous composite was synthesized by a mild temperature acid catalysed sol-gel route where a natural copolymer; sodium alginate (Na-COOH) together with calcium oxide (CaO) powder were incorporated into silica sol precursor prior to gel formation. For this study, bulk xerogels samples were prepared with the amount of silica precursor and the natural copolymer was fixed meanwhile the loading of calcium oxide was varied at 10 and 20 wt%. The monolith silica was also synthesized as control parameter. The preliminary properties were investigated using XRD, FTIR and SEM together with EDS for elemental analysis. The calcium oxide powder used in this study was prepared from calcium hydroxide, CaOH compound, which was previously calcined at 1000°C for 3 hours in normal air. The component of calcium oxide and sodium alginate were found to be uniformly dispersed in matrixes without affecting the cross-linked silica formation. As the presence of the components in the silica matrixes, the synthesized hybrid xerogels were found to be crack-free, structurally amorphous and physically opaque. Furthermore, the hybrid xerogels samples were found to have denser bodies, smoother surface, and decreased in particle sizes and thus might produced less brittleness in nature compared to the monolith xerogels.

scholarly journals Non-aqueous sol–gel synthesis through a low-temperature solvothermal process of anatase showing visible-light photocatalytic activity

RSC Advances ◽  
2014 ◽  
Vol 4 (87) ◽  
pp. 46762-46770 ◽  
Author(s):  
Mohamed Karmaoui ◽  
David M. Tobaldi ◽  
Andrijana Sever Skapin Andrijana Sever Skapin ◽  
Robert C. Pullar ◽  
Maria P. Seabra ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Low Temperature ◽  
Visible Light ◽  
Sol Gel ◽  
Solvothermal Process ◽  
One Pot ◽  
Visible Light Photocatalytic Activity ◽  
Sol Gel Synthesis ◽  
Visible Light Photocatalytic

A novel, facile method based on a non-aqueous sol–gel solvothermal process has been developed to synthesise spherical TiO2 nanoparticles (NPs) in one pot.

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