The phase composition, morphology and compressibility of graphene–zirconia composite nanostructured powder

This work describes the production of nanocrystalline TiO2 and SnO2 oxides, as well as their nanocomposites (containing 26.9, 58.7 and 79.0wt.% of SnO2) with two-stage sol-gel method combined with high temperature treatment. The phase composition and medium size crystallites were determined using X-ray diffraction analysis (XRD) and revealed that the nanocomposites crystallize in tetragonal structures of TiO2 - anatase and SnO2 - cassiterite. Specific surface area of the nanopowders, measured using sorption method (BET), changed from 42.1 to 160.8m2/g. The morphology of the nanopowders was observed using transmission electron microscope (TEM). As indicated by TEM images, the manufactured nanopowders were well crystallized and consisted of small, spherical grains. The obtained nanopowders were also tested for NH3 gas detection application. The presented method of nanopowders synthesis enables to obtain nanocrystalline TiO2 and SnO2 oxides, as well as composites from TiO2-SnO2 of known and controlled chemical and phase composition. It also enables to obtain composites used for gas sensors. The sensor made of composite containing 58.7wt.% of SnO2 exhibited the best NH3 sensing features.

Download Full-text

Preparation and Microwave-Absorption Property of SiO2-SiC-Based Composites

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.434-435.231 ◽

2010 ◽

Vol 434-435 ◽

pp. 231-234

Author(s):

Li Guan ◽

Bing Bing Fan ◽

Ming Liang Li ◽

He Jing Wen ◽

Kai Li ◽

...

Keyword(s):

Solid State ◽

Microwave Absorption ◽

Solid State Reaction ◽

Sol Gel ◽

Composite Particles ◽

Network Analyzer ◽

Epoxide Resin ◽

Maximum Reflectivity ◽

Sol Gel Process ◽

Sic Composites

SiO2-SiC composite particles were prepared using a sol-gel process. BaTiO3 powders were synthesize through solid-state reaction. They were mixed as microwave absorbents with Fe3O4 powders to obtain the complex absorption. Epoxide resin (EP) was used as matrix and solidified with the mixtures. The techniques of DSC-TG, XRD were used to characterize the composite particles and the obtained compacts. A vector network analyzer was used to measure the reflectivity of the SiO2-SiC-based composites. The effects of the aborbents’ contents on the reflection of the microwave absorption materials were disscussed. It was found that SiO2-SiC composites could be prepared using sol-gel process and BaTiO3 powders could be synthesize through solid-state reaction. The results indicated that SiO2-SiC composite is contribute to absorb microwave, where SiO2-SiC: BaTiO3: Fe3O4 = 6:2:2 (vol %), the frequency region in which the maximum reflectivity is more than -10 dB is 5.4-7.6 GHz.

Download Full-text

Effect of MgCl2 addition on the preparation of ZrC–SiC composite particles by sol-gel

Ceramics International ◽

10.1016/j.ceramint.2021.10.034 ◽

2021 ◽

Author(s):

Lei Zheng ◽

Cunqian Fang ◽

Xiao Luo ◽

Ze Zhang ◽

Mingyu Zhang ◽

...

Keyword(s):

Sol Gel ◽

Composite Particles

Download Full-text

PHASE COMPOSITION STABILITY OF NANOSTRUCTURED COMPOSITE CERAMICS BASED ON CaO–ZrO2 UNDER HYDROTHERMAL IMPACT

Nanotechnologies in Russia ◽

10.1134/s1995078019020058 ◽

2019 ◽

Vol 14 (3-4) ◽

pp. 125-131

Author(s):

A. A. Dmitrievskiy ◽

D. G. Zhigacheva ◽

N. Yu. Efremova ◽

A. V. Umrikhin

Keyword(s):

Phase Composition ◽

Composite Ceramics ◽

Nanostructured Composite

Download Full-text

Phase composition, sinterability and bioactivity of amorphous nano-CaO-SiO2-CuO powder synthesized by sol-gel technique

Ceramics International ◽

10.1016/j.ceramint.2020.06.231 ◽

2020 ◽

Vol 46 (15) ◽

pp. 24462-24471

Author(s):

Mohammed A. Taha ◽

Rasha A. Youness ◽

M.F. Zawrah

Keyword(s):

Phase Composition ◽

Sol Gel ◽

Gel Technique

Download Full-text

Elaboration of Sol-Gel Derived Hydroxyapatite / Yttria Stabilized Zirconia Composite Coatings Obtained for Biomedical Application

Defect and Diffusion Forum ◽

10.4028/www.scientific.net/ddf.312-315.894 ◽

2011 ◽

Vol 312-315 ◽

pp. 894-899

Author(s):

Sahar Salehi ◽

Mohammad Hosseien Fathi

Keyword(s):

Grain Size ◽

Crystallite Size ◽

Grain Growth ◽

Biomedical Application ◽

Composite Coatings ◽

Sol Gel ◽

Yttria Stabilized Zirconia ◽

Stabilized Zirconia ◽

Nanostructured Composite

In this study, nanostructured composite coatings of hydroxyapatite (HA)/ 30wt% yttria stabilized zirconia (YSZ) coatings containing 0, 3, 5, and 8 mol% Y2O3 (namely; HA-0YSZ, HA-3YSZ, HA-5YSZ, and HA-8YSZ) were successfully synthesized using the sol-gel method. The crystallite size of the coating was about ~44-58 nm for tetragonal and cubic zirconia grain size and 75-87 nm for hydroxyapatite grain size. Crack-free and homogeneous HA-YSZ composite coatings were obtained with no observable defects. The uniform distribution of zirconia particles in a composite would be highly beneficial for obtaining homogeneous coatings of HA-YSZ film and would hinder grain growth of HA phase during calcinations. In vitro evaluation in 0.9% NaCl showed that Ca2+ dissolution rate of composite coatings was lower than pure HA coatings.

Download Full-text

Dielectric and Sintering Properties of the Doping CaO-B2O3-SiO2 System Low Temperature Co-Fired Ceramics

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.434-435.371 ◽

2010 ◽

Vol 434-435 ◽

pp. 371-375

Author(s):

Ming He ◽

Shu Ren Zhang ◽

Xiao Hua Zhou ◽

Jian Geng Hu ◽

Ting Zhang ◽

...

Keyword(s):

Dielectric Constant ◽

Phase Composition ◽

Low Temperature ◽

Sintered Density ◽

Sol Gel ◽

Calcium Borate ◽

Sio2 System ◽

Sintering Properties ◽

Calcium Silicates ◽

Temperature Melting

. A doping CaO-B2O3-SiO2 system low temperature co-fired ceramics (LTCC) was prepared with a mixture of high temperature melting glass and sol-gel glass for different ratio. The effects of sol-gel glass content on the microstructure, crystalline phases, sintering properties and dielectric properties of CaO-B2O3-SiO2 system were investigated at 850°C. The results show that the samples with sol-gel glass doping had little change in phase composition, but contained more calcium silicates, and less calcium borate. As the amount of sol-gel glass increased, the shrinkage improved, the sintered density slightly decreased, the dielectric constant (εr) reduced, and the dielectric loss (tgδ) decreased. When the amount of sol-gel glass was 14.5wt%, εr and tgδ of the doping sample were 5.80, 4.6×10-5 (at 1 MHz), respectively. Moreover, the doping system had a good matching ability with gold slurry and Au-Pt-Pd slurry.

Download Full-text

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

Crystals ◽

10.3390/cryst10121078 ◽

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.

Download Full-text

Synthesis and characterization of some nanostructured composite oxides for low temperature catalytic combustion of dilute propane

RSC Advances ◽

10.1039/c7ra03916f ◽

2017 ◽

Vol 7 (45) ◽

pp. 27863-27871 ◽

Cited By ~ 15

Author(s):

C. Doroftei ◽

L. Leontie

Keyword(s):

Low Temperatures ◽

Catalytic Combustion ◽

Sol Gel ◽

Catalytic Performance ◽

Synthesis And Characterization ◽

Propane Combustion ◽

Nanostructured Composite ◽

Composite Oxides ◽

Combustion Technique

Five nanosized perovskite and four ferrospinel powders were prepared by sol–gel self-combustion technique. The La0.6Pb0.2Mg0.2MnO3 perovskite was found to exhibit the best catalytic performance with respect to propane combustion at low temperatures.

Download Full-text

Biomorphic SiC Prepared from Carbonized Millet by Sol-Gel and Carbothermal Reduction Processing

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.152-153.1683 ◽

2010 ◽

Vol 152-153 ◽

pp. 1683-1686

Author(s):

Qing Wang ◽

Ya Hui Zhang

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Silicon Carbide ◽

Phase Composition ◽

Carbothermal Reduction ◽

Sol Gel ◽

X Ray Diffraction ◽

X Ray ◽

Carbon Template ◽

Scanning Electron

Biomorphic silicon carbide (bioSiC) was prepared by high temperature pyrolysis and sol-gel and carbothermal reduction processing at 1600 oC. The morphology and microstructure of carbon-silica composites and purified bioSiC samples were characterized by scanning electron microscopy. The phase composition of the resulting sample was analyzed by X-ray diffraction. The results suggest that the bioSiC mainly consists of cubic ß-SiC, and principally replicates the shape and microstructure of the carbon template.

Download Full-text