scholarly journals Ga-Substituted Cobalt-Chromium Spinels as Ceramic Pigments Produced by Sol–Gel Synthesis

Crystals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1078
Author(s):  
Egle Grazenaite ◽  
Edita Garskaite ◽  
Zivile Stankeviciute ◽  
Eva Raudonyte-Svirbutaviciene ◽  
Aleksej Zarkov ◽  
...  
Keyword(s):  
Phase Composition ◽  
Crystallite Size ◽  
Single Phase ◽  
Sol Gel ◽  
Ceramic Pigments ◽  
Blue Color ◽  
Cobalt Chromium ◽  
Light Blue ◽  
Sol Gel Synthesis ◽  
First Time

For the first time to the best of our knowledge, cobalt-chromium spinels CoCr2−xGaxO4 with different amounts of gallium (x = 0–2 with a step of 0.5) were synthesized via the aqueous sol–gel route as ceramic pigments. The phase composition, crystallite size, morphological features, and color parameters of new compositions and their corresponding ceramic glazes were investigated using XRD, CIELab, SEM, and optical microscopy. It was demonstrated that the formation of single-phase CoCr2−xGaxO4 samples was problematic. Full substitution of Cr3+ by Ga3+ ion in the spinel resulted in the formation of light blue powders, which yielded violetish blue color for the corresponding ceramic glaze.

Sol–gel synthesis of 2-dimensional TiO2: self-assembly of Ti–oxoalkoxy–acetate complexes by carboxylate ligand directed condensation

2021 ◽  
Author(s):  
Ruohong Sui ◽  
Connor E. Deering ◽  
Rohen Prinsloo ◽  
Christopher B. Lavery ◽  
Nancy Chou ◽  
...  
Keyword(s):  
Self Assembly ◽  
Sol Gel ◽  
Carboxylate Ligand ◽  
Sol Gel Synthesis ◽  
First Time

2-Dimensional TiO2 is synthesized for the first time by a sol–gel self-assembly of Ti–oxoalkoxy–acetate complexes.

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.

AN INVESTIGATION INTO MECHANOCHEMICAL SYNTHESIS OF NANOCRYSTALLINE HEXAFERRITE POWDER

2011 ◽  
Vol 25 (07) ◽  
pp. 987-993
Author(s):  
S. SADEGHI-NIARAKI ◽  
S. A. SEYYED EBRAHIMI ◽  
SH. RAYGAN
Keyword(s):  
Crystallite Size ◽  
Single Phase ◽  
Sol Gel ◽  
Milled Powder ◽  
Particle Morphology ◽  
Average Crystallite Size ◽  
Phase Evolution ◽  
High Energy ◽  
Strontium Hexaferrite ◽  
Electron Microscopes

Nanocrystalline strontium hexaferrite powder has been prepared by a new mechanochemical method in which the single phase hexaferrite was obtained via a sol–gel autocombustion process followed by an intermediate high energy milling step and subsequent annealing. The effects of the intermediate milling on the phase evolution, crystallite size and annealing behavior of the final products were investigated using the X-ray diffraction (XRD) technique. The single phase strontium hexaferrite was obtained at an annealing temperature of 800°C, while this temperature was 1,000°C for the powder synthesized without milling. It could be seen that an intermediate milling accelerates the formation of strontium hexaferrite during the calcination process. The results showed that in the milled powder, the average crystallite size of the ferrite was about 40 nm and much smaller than that of the nonmilled powder. Magnetic properties were also measured by a vibrating sample magnetometer (VSM). The particle morphology was then studied by scanning and transmission electron microscopes (SEM and TEM).

Sol-gel synthesis, solid sintering, and thermal stability of single-phase YCoO3

2012 ◽  
Vol 209 (7) ◽  
pp. 1219-1224 ◽  
Author(s):  
Guanlin Feng ◽  
Yanfeng Xue ◽  
Hongzhi Shen ◽  
Shuo Feng ◽  
Liang Li ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Single Phase ◽  
Sol Gel ◽  
Sol Gel Synthesis ◽  
Thermal Stability Of

Sol–gel synthesis, structural and electrical properties of Li2CoSiO4 cathode material

2014 ◽  
Vol 07 (06) ◽  
pp. 1440001 ◽  
Author(s):  
Michał Świętosławski ◽  
Marcin Molenda ◽  
Piotr Natkański ◽  
Piotr Kuśtrowski ◽  
Roman Dziembaj ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Sol Gel ◽  
Lithium Ion ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Structural And Electrical Properties ◽  
Potential Alternative ◽  
Sol Gel Synthesis ◽  
First Time

Polyanionic cathode materials for lithium-ion batteries start to be considered as potential alternative for layered oxide materials. Among them, Li 2 CoSiO 4, characterized by outstanding capacity and working voltage, seems to be an interesting substitute for LiFePO 4 and related systems. In this work, structural and electrical investigations of Li 2 CoSiO 4 obtained by sol–gel synthesis were presented. Thermal decomposition of gel precursor was studied using EGA (FTIR)-TGA method. Chemical composition of the obtained material was confirmed using X-ray diffraction and energy-dispersive X-ray spectroscopy. The morphology of β- Li 2 CoSiO 4 was studied using transmission electron microscopy. High temperature electrical conductivity of Li 2 CoSiO 4 was measured for the first time. Activation energies of the electrical conductivity of two Li 2 CoSiO 4 polymorphs (β and γ) were determined. The room temperature electrical conductivity of those materials was estimated as well.

Morphology and Phase Composition of Sol-Gel Derived Aluminum Borate Nanowhiskers

2015 ◽  
Vol 659 ◽  
pp. 121-126 ◽  
Author(s):  
Pat Sooksaen
Keyword(s):  
Fourier Transform ◽  
Phase Composition ◽  
Sol Gel ◽  
Molar Ratio ◽  
Aluminum Borate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Higher Temperature ◽  
Sol Gel Synthesis ◽  
Scanning Electron

Aluminium borate nanowhiskers with varying aspect ratio were synthesized via sol–gel synthesis. The morphology of aluminum borate (Al4B2O9 and Al18B4O33) nanowhiskers could be controlled by varying the aluminum to boron (Al:B) molar ratio in the sol–gel derived precursors. Sintering temperatures (850 and 1100°C) and sintering times (4 and 32 hours) also affected the phase composition and size of the nanowhiskers. Citric acid was also added in the sol–gel derived precursors as a surface stabilizer for obtaining uniform finely dispersed nanostructures. Fine nanowhiskers were obtained by the calcination at 850°C, whereas higher temperature of 1100°C led to thicker and longer nanowhiskers and became rod-like crystals. The morphology and phase composition were investigated by field emission scanning electron microscope and X-ray diffraction. Chemical bond vibrations in the synthesized nanowhiskers were investigated by Fourier-transform infrared spectroscopy.

scholarly journals Formation of nanoscopic CaF2via a fluorolytic sol–gel process for antireflective coatings

2015 ◽  
Vol 3 (8) ◽  
pp. 1716-1723 ◽  
Author(s):  
Alexander Rehmer ◽  
Kerstin Scheurell ◽  
Erhard Kemnitz
Keyword(s):  
Sol Gel ◽  
Nano Particles ◽  
Antireflective Coatings ◽  
Sol Gel Process ◽  
Sol Gel Synthesis ◽  
First Time

For the first time transparent antireflective CaF2-coatings were prepared from clear CaF2-sols obtained via the fluorolytic sol–gel synthesis and containing homo-dispersed CaF2 nano-particles.

Sol–gel synthesis and characterization of Fe2O3 · CeO2 doped with Pr ceramic pigments

2008 ◽  
Vol 47 (1) ◽  
pp. 38-43 ◽  
Author(s):  
M. G. B. Nunes ◽  
L. S. Cavalcante ◽  
V. Santos ◽  
J. C. Sczancoski ◽  
M. R. M. C. Santos ◽  
...  
Keyword(s):  
Sol Gel ◽  
Synthesis And Characterization ◽  
Ceramic Pigments ◽  
Sol Gel Synthesis

Investigation in Optimization Process Parameter of CaCu3Mn4O12 via Sol-Gel Synthesis

2013 ◽  
Vol 465-466 ◽  
pp. 834-838
Author(s):  
A. Nurulhuda ◽  
Ali Rafidah ◽  
Arshad Azrina ◽  
Yacob Suhaila ◽  
I.S. Anwar ◽  
...  
Keyword(s):  
Low Temperature ◽  
Single Phase ◽  
Sol Gel ◽  
Magnetic Behavior ◽  
Molar Ratio ◽  
Processing Temperature ◽  
Sintering Process ◽  
Fine Size ◽  
Sol Gel Synthesis ◽  
Sintering Condition

Due to the disadvantageous of solid state in CaCu3Mn4O12 ceramic processing, the sol gel synthesis has been extensively studied to produce fine size of powder and better homogeneity at low processing temperature. This paper provides a summary to prove that the single phase of CaCu3Mn4O12 ceramic with high purity and characteristic is actually can be produced via sol gel synthesis at relative low temperature under pressureless sintering process. The stoichiometric CaCu3Mn4O12 powders were successfully prepared by the citric gel method with molar ratio of [citrates/metallic io; 1:2. The precursor gel formed was calcined and sintered at range 400 °C to 800 °C. A single-phase CaCu3Mn4O12 fairly well densified at relative low temperature under atmospheric sintering condition. Analysis has been done under XRD and FESEM. Result shown formation of CaCu3Mn4O12 started at 500 °C and was formed completely at 700 °C for 18h. FESEM results turned out that CaCu3Mn4O12 powder particle is submicron in size and highly agglomerates due to high calcinations temperature. Varying in sintering parameter is actually exhibit differences in phase formation, grain size and magnetic behavior.

scholarly journals Effect of Samarium Substitution on the Structural and Magnetic Properties of Nanocrystalline Cobalt Ferrite

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Sheena Xavier ◽  
Smitha Thankachan ◽  
Binu P. Jacob ◽  
E. M. Mohammed
Keyword(s):  
Crystallite Size ◽  
Single Phase ◽  
Sol Gel ◽  
Average Crystallite Size ◽  
Lattice Parameter ◽  
Magnetic Characteristics ◽  
Typical Sample ◽  
Cobalt Ferrites ◽  
Phase Spinel ◽  
Structural Characterizations

A series of samarium-substituted cobalt ferrites (CoFe2−xSmxO4 with x=0.00, 0.05, 0.10, 0.15, 0.20, 0.25) was synthesized by the sol-gel method. The structural characterizations of all the prepared samples were done using XRD and FTIR. These studies confirmed the formation of single-phase spinel structure in all the compositions. The increase in the value of lattice parameter with increase in samarium concentration suggests the expansion of unit cell. The Hall-Williamson analysis is used for estimating the average crystallite size and lattice strain induced due to the substitution of samarium in the prepared samples. Crystallinity and the crystallite size are observed to increase with the concentration of samarium. The surface morphology and particle size of a typical sample were determined using SEM and TEM respectively. The substitution of samarium strongly influences the magnetic characteristics, and this is confirmed from the magnetization measurements at room temperature.

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