Application of Sol-Gel Method to Investigate the Influence of P2O5 on the Course of Reactions in CaO-SiO2 System

The effect of P2O5 addition on the calcium silicate phase equilibrium during the sol-gel synthesis of dicalcium silicate was investigated using Scanning electron microscope and X-ray diffraction. It is established that phosphorous oxide can form solid solution with dicalcium silicate, but its causes the formation of phosphatic calcium silicate phases such as Ca14.92 (PO4)2.35(SiO4)5.65 and 5CaO.SiO2.P2O5 also. Local analysis has demonstrated the presence of calcium phosphate epicenters containing silicon oxide and calcium silicate zones with minimum content of phosphorous oxide and intermediary areas of various phosphatic calcium silicates. The formation of two distinct islets of calcium silicate and calcium phosphate is due to the affinity between acid oxides (SiO2, P2O5) and basic one (CaO) during sol-gel process. Then, the formation of various phosphatic calcium silicates result from the diffusion of P2O5 towards calcium silicate and that of SiO2 towards calcium phosphate.

Download Full-text

Study of Pseudoboehmite Synthesis by Sol-Gel Process

Advances in Science and Technology ◽

10.4028/www.scientific.net/ast.45.260 ◽

2006 ◽

Vol 45 ◽

pp. 260-265 ◽

Cited By ~ 19

Author(s):

Antônio Hortêncio Munhoz Jr. ◽

Leila Figueiredo de Miranda ◽

G.N. Uehara

Keyword(s):

Sol Gel ◽

Thermo Gravimetric Analysis ◽

Ammonium Hydroxide ◽

Gravimetric Analysis ◽

X Ray Diffraction ◽

Scanning Calorimetry ◽

X Ray ◽

Sol Gel Process ◽

Different Temperatures ◽

Sol Gel Synthesis

A pseudoboehmite was obtained by sol-gel synthesis using aluminum nitrate as precursor. It was used a 2n full factorial design for studying the effect of the temperature of synthesis, the concentration of ammonium hydroxide, and the radiation dose in the product of sol-gel synthesis. The product of the synthesis was analyzed by scanning electron microscopy, x-ray diffraction of the product (after firing the pseudoboehmite at different temperatures), and it was also analyzed the temperature of endothermic and exothermic transformations using the thermo gravimetric analysis (TG) and differential scanning calorimetry (DSC). The X-ray diffraction data show that α-alumina was obtained at 1100o C.

Download Full-text

Sol-gel synthesis and study of neodymium substitution effects in Co-Al-Nd-O system with possible applications as novel inorganic pigments

Open Chemistry ◽

10.2478/s11532-012-0072-8 ◽

2012 ◽

Vol 10 (5) ◽

pp. 1574-1583 ◽

Cited By ~ 1

Author(s):

Dalia Jonynaite ◽

Darius Jasaitis ◽

Rimantas Raudonis ◽

Algirdas Selskis ◽

Remigijus Juskenas ◽

...

Keyword(s):

Sol Gel ◽

Substitution Effects ◽

X Ray Diffraction ◽

X Ray ◽

Force Microscopy ◽

Atomic Force ◽

Sol Gel Process ◽

New Compounds ◽

Sol Gel Synthesis

AbstractIn the present work, the formation of cobalt aluminium spinel (CoAl2O4) as well as novel cobalt neodymium-aluminates with nominal compositions of CoAl1.75Nd0.25O4, CoAl1.5Nd0.5O4 and CoAlNdO4 by an aqueous sol-gel process and the sinterability of the products are investigated. The metal ions, generated by dissolving starting materials of metals in the diluted acetic acid were complexed by 1,2-ethanediol to obtain the precursors for the mixed metal ceramics. The phase purity of the synthesized compounds was characterized by powder X-ray diffraction analysis and infrared spectroscopy. The microstructural evolution and morphological features of the products were studied by scanning electron microscopy and atomic force microscopy, which together with the optical characterization of these new compounds showed that the sol-gel-derived materials could be successfully used as effective cobalt-based ceramic pigments.

Download Full-text

Synthesis of Core–Double Shell Nylon-ZnO/Polypyrrole Electrospun Nanofibers

Nanomaterials ◽

10.3390/nano10112241 ◽

2020 ◽

Vol 10 (11) ◽

pp. 2241

Author(s):

Mihaela Beregoi ◽

Nicoleta Preda ◽

Andreea Costas ◽

Monica Enculescu ◽

Raluca Negrea ◽

...

Keyword(s):

Sol Gel ◽

Electrospun Nanofibers ◽

Spectroscopic Techniques ◽

X Ray Diffraction ◽

Zno Film ◽

X Ray ◽

Wide Range ◽

Sol Gel Process ◽

Sol Gel Synthesis ◽

Inorganic Layers

Core–double shell nylon-ZnO/polypyrrole electrospun nanofibers were fabricated by combining three straightforward methods (electrospinning, sol–gel synthesis and electrodeposition). The hybrid fibrous organic–inorganic nanocomposite was obtained starting from freestanding nylon 6/6 nanofibers obtained through electrospinning. Nylon meshes were functionalized with a very thin, continuous ZnO film by a sol–gel process and thermally treated in order to increase its crystallinity. Further, the ZnO coated networks were used as a working electrode for the electrochemical deposition of a very thin, homogenous polypyrrole layer. X-ray diffraction measurements were employed for characterizing the ZnO structures while spectroscopic techniques such as FTIR and Raman were employed for describing the polypyrrole layer. An elemental analysis was performed through X-ray microanalysis, confirming the expected double shell structure. A detailed micromorphological characterization through FESEM and TEM assays evidenced the deposition of both organic and inorganic layers. Highly transparent, flexible due to the presence of the polymer core and embedding a semiconducting heterojunction, such materials can be easily tailored and integrated in functional platforms with a wide range of applications.

Download Full-text

DIP-COATING SENYAWA KALSIUM FOSFAT DARI BATU KAPUR BUKIT TUI MELALUI METODE SOL-GEL

Jurnal Riset Kimia ◽

10.25077/jrk.v5i1.179 ◽

2015 ◽

Vol 5 (1) ◽

pp. 46

Author(s):

Novesar Jamarun ◽

Lia Anggresani ◽

Syukri Arief

Keyword(s):

Calcium Phosphate ◽

Thin Layer ◽

Sol Gel ◽

Dip Coating ◽

X Ray Diffraction ◽

Sem Images ◽

X Ray ◽

Sol Gel Process ◽

Xrd Patterns ◽

Diammonium Hydrogen

ABSTRACT Preparation of Dip-Coating Calcium Phosphate via sol-gel method using natural limestone Bukit Tui as calcium precursors and diammonium hydrogen phosphate as phosphorus precursors with sol-gel process has been investigated. Ethanol was used as solvent and DEA (diethanolamine) was used stabilizing agent. The powder were prepared by calcinated the sol at 950 oC. The products were characterized by Fourier Transform Infra Red, X-Ray Diffraction and Scanning Electron Microscopy. FTIR results showed that the vibration form was PO43-, P2O74-, O-H and CO2. XRD patterns of powder with various Ca/P mol ratio showed that the product of calcium phosphate was Ca2P2O7 and also found the hydroxyapatite Ca10(PO4)6(OH)2 in Ca/P mol ratio 1,7. SEM images of powder calcium phosphate revealed that their morphology were spheric and homogen. The coating process was done at glass substrate with coating speed 20 cm/min by calcinations at 400 oC. XRD patterns of thin layer showed that the product was Ca2P2O7 and SEM images of thin layer revealed that their morphology were bulk. Keywords: Natural limestone, calcium phosphate, hydroxyapatite, sol-gel, dip-coating

Download Full-text

Sodium Solid Electrolytes: NaxAlOy Bilayer-System Based on Macroporous Bulk Material and Dense Thin-Film

Materials ◽

10.3390/ma14040854 ◽

2021 ◽

Vol 14 (4) ◽

pp. 854

Author(s):

Antonia Hoppe ◽

Cornelius Dirksen ◽

Karl Skadell ◽

Michael Stelter ◽

Matthias Schulz ◽

...

Keyword(s):

Pore Size ◽

Bulk Material ◽

Sol Gel ◽

Dense Layer ◽

X Ray Diffraction ◽

Bilayer System ◽

Step Procedure ◽

Short Circuits ◽

Α Al2o3 ◽

Sol Gel Synthesis

A new preparation concept of a partially porous solid-state bilayer electrolyte (BE) for high-temperature sodium-ion batteries has been developed. The porous layer provides mechanical strength and is infiltrated with liquid and highly conductive NaAlCl4 salt, while the dense layer prevents short circuits. Both layers consist, at least partially, of Na-β-alumina. The BEs are synthesized by a three-step procedure, including a sol-gel synthesis, the preparation of porous, calcined bulk material, and spin coating to deposit a dense layer. A detailed study is carried out to investigate the effect of polyethylene oxide (PEO) concentration on pore size and crystallization of the bulk material. The microstructure and crystallographic composition are verified for all steps via mercury intrusion, X-ray diffraction, and scanning electron microscopy. The porous bulk material exhibits an unprecedented open porosity for a NaxAlOy bilayer-system of ≤57% with a pore size of ≈200–300 nm and pore volume of ≤0.3 cm3∙g−1. It contains high shares of crystalline α-Al2O3 and Na-β-alumina. The BEs are characterized by impedance spectroscopy, which proved an increase of ionic conductivity with increasing porosity and increasing Na-β-alumina phase content in the bulk material. Ion conductivity of up to 0.10 S∙cm−1 at 300 °C is achieved.

Download Full-text

V2O3/C composite fabricated by carboxylic acid-assisted sol–gel synthesis as anode material for lithium-ion batteries

Journal of Sol-Gel Science and Technology ◽

10.1007/s10971-021-05523-z ◽

2021 ◽

Author(s):

G. S. Zakharova ◽

E. Thauer ◽

A. N. Enyashin ◽

L. F. Deeg ◽

Q. Zhu ◽

...

Keyword(s):

Electrochemical Performance ◽

Lithium Ion Batteries ◽

Sol Gel ◽

Carbon Sources ◽

Lithium Ion ◽

X Ray Diffraction ◽

Electron Microscopies ◽

Transmission Electron ◽

Battery Electrode ◽

Sol Gel Synthesis

AbstractThe potential battery electrode material V2O3/C has been prepared using a sol–gel thermolysis technique, employing vanadyl hydroxide as precursor and different organic acids as both chelating agents and carbon sources. Composition and morphology of resultant materials were characterized by X-ray diffraction, Raman spectroscopy, scanning and transmission electron microscopies, physical sorption, and elemental analysis. Stability and electronic properties of model composites with chemically and physically integrated carbon were studied by means of quantum-chemical calculations. All fabricated composites are hierarchically structured and consist of carbon-covered microparticles assembled of polyhedral V2O3 nanograins with intrusions of amorphous carbon at the grain boundaries. Such V2O3/C phase separation is thermodynamically favored while formation of vanadium (oxy)carbides or heavily doped V2O3 is highly unlikely. When used as anode for lithium-ion batteries, the nanocomposite V2O3/C fabricated with citric acid exhibits superior electrochemical performance with an excellent cycle stability and a specific charge capacity of 335 mAh g−1 in cycle 95 at 100 mA g−1. We also find that the used carbon source has only minor effects on the materials’ electrochemical performance.

Download Full-text

Luminescent Properties of Zn2SiO4:Eu3+,Dy3+ Phosphors via Sol-Gel Process

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.217-219.733 ◽

2012 ◽

Vol 217-219 ◽

pp. 733-736

Author(s):

Xiu Mei Han ◽

Shu Ai Hao ◽

Ying Ling Wang ◽

Gui Fang Sun ◽

Xi Wei Qi

Keyword(s):

Thermal Analysis ◽

Ir Spectra ◽

Sol Gel ◽

Luminescent Properties ◽

Photoluminescence Spectra ◽

X Ray Diffraction ◽

X Ray ◽

Sol Gel Process ◽

Ft Ir

Zn2SiO4:Eu3+, Dy3+ phosphors have been prepared through the sol-gel process. X-ray diffraction (XRD), thermogravimetric and ddifferential thermal analysis (TG-DTA), FT-IR spectra and photoluminescence spectra were used to characterize the resulting phosphors. The results of XRD indicated that the phosphors crystallized completely at 1000oC. In Zn2SiO4:Eu3+,Dy3+ phosphors, the Eu3+ and Dy3+ show their characteristic red(613nm, 5D0-7F2), blue (481nm, 4F9/2–6H15/2) and yellow (577nm, 4F9/2–6H13/2) emissions.

Download Full-text

The Preparation and Photocatalytic Activity of SWNTs Doped ZnO/TiO2 Compound Films

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.97-101.1611 ◽

2010 ◽

Vol 97-101 ◽

pp. 1611-1615 ◽

Cited By ~ 1

Author(s):

Qing Wang ◽

Xin Li Li ◽

Wei Nie ◽

Yong Mei Xia ◽

Jian Feng Dai

Keyword(s):

Photocatalytic Activity ◽

Absorption Spectra ◽

Sol Gel ◽

Composite Films ◽

Wavelength Region ◽

Tio2 Films ◽

X Ray Diffraction ◽

Sol Gel Process ◽

Doped Zno ◽

Walled Carbon Nanotubes

The ZnO/TiO2 composite films were deposited over glass using spin coating technique by sol-gel process. Single-walled carbon nanotubes (SWNTs) were used to modify the ZnO/TiO2 films successfully in this paper. The structure and composition of the ZnO/TiO2 composite and SWNTs doped ZnO/TiO2 composite were characterized by X-ray diffraction (XRD). The morphology of samples was characterized by scanning electron microscopy (SEM). The photocatalytic activity was investigated by photocatalytic degradation of aqueous methyl orange under ultraviolet (UV) radiation. The UV-vis absorption spectra of the ZnO/TiO2 films and SWNTs doped ZnO/TiO2 films in the wavelength region 200~800 nm were obtained. The results indicate that the SWNTs addition can decrease the grain size of ZnO/TiO2, which can enhance the photocatalytic activity. UV-vis absorption spectra of SWNTs-ZnO/TiO2 showed obvious blue shifts compared with ZnO/TiO2. The optimal amount of doping SWNTs is 1% according to this research. The enhanced mechanism of the SWNTs for the photocatalytic activity in ZnO/TiO2 films was analyzed in this article.

Download Full-text