Showing papers on "Sol-gel published in 2016"
TL;DR: Powders Nb2 O5 were prepared by two different synthesis method, Sol-Gel and polymeric precursors (Pechini), in the Pechini method before adding the citric acid in the process, four different solutions were used to get the samples.
Abstract: Powders Nb2 O5 were prepared by two different synthesis method, Sol-Gel and polymeric precursors (Pechini). In the Pechini method before adding the citric acid in the process, four different solutions were used to get the samples. For Sol-gel method, two different processes were also used in obtaining powders. The precursor was completely solubilized in ethanol and then hydrolyzed with ammonia and water. The calcination of the samples was between 500 and 750°C. The resulting powders were characterized by Scanning Electron Microscopy (SEM), Brunauer, Emmett and Teller (BET) surface area measurements, UV-visible and Raman spectroscopy. The formation of T−Nb2 O5 orthorhombic took place upon calcination at 7500C. Crystallite sizes were determined using the Scherrer method which resulted in an uniformed size of about 25 − 65nm. Ultraviolet-Visible diffuse reflectance spectroscopy indicated a variation in the optical band gap values (3.32-3.40 eV) in crystal growth process. The Raman vibrational modes indicate the presence of the orthorhombic phase of the material.
98 citations
TL;DR: In this paper, the authors synthesize silica nanoparticles using sol-gel method using Tetraethyl orthosilicate as a precursor and use distilled water as catalyst and hydrolyzing agent.
Abstract: Sol-gel method is the simplest method and has the ability to control the particle size and morphology through
systematic monitoring of reaction parameters. The objective of this research is to synthesize silica nanostructures
by sol-gel method and to characterize the synthesized silica nanostructures. Silica nanoparticles were synthesized
via the sol-gel method using Tetraethyl orthosilicate as a precursor. The acetic acid and distilled water were used as
the catalyst and the hydrolyzing agent. Varied parameters of the study were the aging time in the range of 2 to 6 h
and the calcination temperature in the range of 600–700 ◦C. The obtained silica nanopowder was characterized
using FESEM, and Nano-Particle Size Analyzer. The results show that the silica nanospheres were successfully
synthesized by using sol-gel method with the optimum parameters of 700 ◦C of calcination temperature and 2 h of
aging time. The average size of silica nanoparticles was in the range of 79.68 nm to 87.35 nm.
73 citations
TL;DR: In this paper, the p-type thin film transistors with solution-processed channels using a sol-gel route, based on a copper (II) acetate precursor, were realized.
70 citations
TL;DR: In this paper, a highly efficient lithium orthosilicate (CSG-Li 4 SiO 4 ) was synthesized using a sol-gel method combined with carbon coating, and the presence of citric acid played dual roles, serving as a complexing agent that homogeneously mixed the precursors and as a carbon source.
69 citations
TL;DR: In this article, the authors have discussed the gas sensing characteristics of Zinc Oxide thin films prepared by dip coating method using Zinc nitrate hexahydrate (Zn (NO3)2)2 and organic polymer Na-CMC as a starting material.
69 citations
TL;DR: In this paper, the thermal properties of the synthesized gel-glass materials were studied as a function of the Ca/P molar ratio using thermogravimetric and differential thermal analysis (TG/DTA).
65 citations
TL;DR: In this paper, a modified colloidal sol-gel process using a mixture of Zr-inorganic salts and Ti-alkoxides was used to synthesize nanometer-sized TiO2-ZrO2 (TZ) sols with an average hydrodynamic diameter of 2.5 nm.
62 citations
TL;DR: Transparent conducting Tin doped Cadmium oxide thin films were prepared by sol-gel spin coating method with different Sn concentrations as discussed by the authors, and X-ray diffraction analysis revealed the polycrystalline natur...
58 citations
TL;DR: In this article, the structure and properties of the core-shell Fe3O4 and SiO2 nanoparticles were characterized and the results showed that these nanoparticles are a soft magnetic material.
Abstract: Using a sol–gel method, silica-coated magnetite (Fe3O4
@SiO2) core-shell nanoparticles were fabricated following a two-step process. In the first step, the Fe3O4 nanoparticles were prepared via a solvothermal method. In the second step, the Fe3O4 nanoparticles were coated with SiO2 formed through the hydrolyzation of tetraethyl orthosilicate. The structure and properties of the core-shell Fe3O4
@SiO2 nanoparticles were characterized and the results showed that Fe3O4
@SiO2 nanoparticles are a soft magnetic material. A magnetorheological (MR) suspension was prepared based on the synthesized Fe3O4
@SiO2 nanoparticles dispersed in silicone oil and measured using a rotational rheometer at various magnetic field strengths. Using a rotational rheometer, the MR properties of the Fe3O4
@SiO2 in silicone oil, including shear stress, shear viscosity, and yield stress were examined under an applied magnetic field.
57 citations
TL;DR: In this paper, a fluorinated polymeric sol-gel precursor (PFT) is synthesized by copolymerization of 2,3,4,5, 5,5-hexafluoro-2,4-bis(trifluorinated methyl)pentyl methacrylate (FMA) and 3-methacryloxypropyltrimethoxysilane (TSMA) to replace the expensive long chain fluorinated alkylsilanes.
57 citations
TL;DR: In this paper, high-purity Y2O3 nanopowder has been prepared by the Pechini sol-gel method using citric acid and ethylene glycol as the chelating agent and complexant of Y3+ cations.
Abstract: High-purity Y2O3 nanopowder has been prepared by the Pechini sol–gel method using citric acid and ethylene glycol as the chelating agent and complexant of Y3+ cations. The crystal structure of the powder has been studied by means of X-ray diffraction (XRD). In order to evaluate the bonding characteristics of the obtained gel, Fourier transform infrared spectroscopy (FTIR) was carried out. Morphological properties of the nanopowders were examined through field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM), respectively. Using spark plasma sintering (SPS) at 1100 °C for 5 min under the uniaxial pressure of 100 MPa,
the consolidation of the nanopowder was accomplished. Scanning electron microscopy (SEM) was used to investigate the microstructure of compacted pellets. The compacted specimen was made up of grains in the size range of approximately 40 µm. Furthermore, the optical properties of compacted powder were investigated by means of spectrophotometer. The final obtaining Y2O3 pellet exhibited the in-line transmittance of 60 % at the wavelength of 700 nm.
TL;DR: In this paper, the photocatalytic and self-cleaning properties of thin films were evaluated by measuring the contact angle of water droplet on the thin films with and without fluorescent irradiation.
TL;DR: In this article, the surface morphology and structural characteristics were determined through scanning electron microscopy, atomic force microscopy and X-ray diffraction, and the Fourier transform infrared spectroscopy validated the formation of Al-doped ZnO film on glass substrate.
Abstract: In this study, pure ZnO and Al-doped ZnO thin films were developed on glass by sol–gel process followed by drying and annealing in air at 170 and 400 °C, respectively. The surface morphology and structural characteristics were determined through scanning electron microscopy, atomic force microscopy and X-ray diffraction. The Fourier transform infrared spectroscopy validated the formation of Al-doped ZnO film on glass substrate. It was evaluated that 1 at% aluminum (Al) doping in ZnO film showed low electrical resistivity and higher charge carrier concentration due to uniformly dispersed regular shape crystallites as compared to pure ZnO and 2 at% ‘Al’-doped thin films.
TL;DR: In this article, powder X-ray Diffraction (XRD), Field Emission Scanning Electron Microscopes (FESEM) and Fourier Transform Infrared spectroscopy (FTIR) were used to identify rare earth (RE) substituted cobalt ferrite.
TL;DR: In this article, the optical and surface properties of spin coated Zn1−xMxO films (M=Na or La and x≤0.075) are reported.
TL;DR: In this paper, 10GDC powders (Gd 0.1 Ce 0.9 O 1.95 ) were synthesized by sol-gel combustion and solgel synthesis routes using the same complexing agents in both procedures.
TL;DR: In this paper, a ZrO2-SiO2 powder was prepared by the sol-gel method and subsequently sintered by Spark Plasma Sintering (SPS).
Abstract: Transparent ZrO2-SiO2 glass ceramics show potential for application in the dental industry. The application of this material prepared by a sol-gel method was hindered by the difficulties in obtaining large dimension samples. Spark plasma sintering (SPS) offers the possibility of achieving transparent ZrO2-SiO2 glass ceramics. In this study, a ZrO2-SiO2 powder was prepared by the sol-gel method and subsequently sintered by SPS. Varied sintering temperatures and pressures were explored to achieve better mechanical strength and transparency. TEM results showed single crystalline ZrO2 spherical nanocrystals (approximately 20 nm) homogenously embedded in the SiO2 matrix. Tetragonal ZrO2 was the only crystalline phase in all specimens. With sintering conditions of 1200° C and 30 MPa, a glass ceramic with fracture toughness of 4.13 MPa m was obtained. This value is similar to the commercial dental glass ceramic of IPS e.max® Press. The studied transparent glass ceramic with high transparency and moderate mechanical strength shows promise for dental application.
TL;DR: In this paper, the authors used differential thermal analysis (DTA), X-ray diffraction, transmission electron microscopy (TEM), selected area electron diffraction (SAED) and high resolution TEM (HRTEM) to study anatase transition to rutile TiO 2 from titanium dioxide precursor powders.
TL;DR: Graphene/titanium carbide composites were synthesized by means of sol-gel infiltration and spark plasma sintering (SPS) as mentioned in this paper, which allowed the formation of nanostructured ceramics inside the porous structure of graphene networks, thus forming composites.
TL;DR: In this article, the resistivity stability of al-doped zinc oxide (AZO) thin films was investigated in ambient or damp heat environment, where the degradation rate was influenced by annealing temperature.
TL;DR: In this paper, an extended aging of wet gels in aqueous solution containing precursor-derived species is found to be crucial in obtaining crack-free, monolithic xerogels with sufficiently low thermal conductivity.
Abstract: Ambient pressure drying of polymethylsilsesquioxane gels via dynamic shrinkage-reexpansion has been investigated for preparation of aerogel-like xerogels and their application to thermal superinsulators. An extended aging of wet gels in aqueous solution containing precursor-derived species is found to be crucial in obtaining crack-free, monolithic xerogels with sufficiently low thermal conductivity (13.7 mW m − 1 K − 1 ) at bulk density of 0.140 g cm − 3 (porosity ~ 90%).
TL;DR: In this paper, complex oxide Y 2.5 Nd 0.5 Al 5 O 12 and NdPO 4 were processed by Spark Plasma Sintering (SPS), relative density more 98%, sintering time did not exceed 8min, sinter temperature 1330-1390 ǫ c.
TL;DR: In this article, a spin-coating technique was used to obtain calcium hydroxyapatite (Ca 10 (PO 4 ) 6 (OH) 2, CHAp) films on silicon substrates.
TL;DR: In this paper, the effects of chromium on the structural, morphological and optical properties of the zinc oxide films were investigated by using atomic force microscopy (AFM), X-ray diffraction (XRD), and UV-vis-NIR spectrophotometer.
TL;DR: In this paper, the particle size distribution and morphology of silica nanoparticles were determined using dynamic light scattering (DLS) analysis and field emission scanning electron microscopy (FE-SEM).
Abstract: Silica nanoparticles were synthesized using the sol-gel method in an acidic environment containing tetraethyl orthosilicate (TEOS) and hydrochloric acid (HCl), and the particle size distribution and morphology of silica nanoparticles were determined using dynamic light scattering (DLS) analysis and field emission scanning electron microscopy (FE-SEM). The results show that the product is highly monodisperse and composed of amorphous SiO2 nanoparticles. Afterwards, a facile route for dispersion of nanoparticles in bentonite suspensions, low-salinity and high-salinity muds, was explained and the stability of the dispersions at different experimental conditions was investigated. Finally, the effect of silica nanoparticles on rheological properties and fluid filtration behavior was investigated using the API filter press test. The presented dispersion method in this study showed superior performance to previous dispersion methods.
TL;DR: Low temperature sol-gel glass coatings to modify the substrate surface and to evaluate their bioactivity and biocompatibility were developed and the potential applications of the coatings in the biomedical field were evaluated.
TL;DR: In this paper, the effect of preparation conditions on the microstructure and some magnetic properties of Co 0.8 Fe 2.2 O 4 was investigated via X-ray diffraction and vibrating sample magnetometry.
TL;DR: In this article, the impact of the solgel precursor treatment with preheating temperature on the properties of the CZTS thin films and its photovoltaic solar cell has been investigated.
TL;DR: The promising results obtained in this study suggest that the CHAR film was considered as an essential component of the solar module and were expected to provide additional solar energy harvest under extreme outdoor climates.
Abstract: Making use of a facile and low-cost way for the preparation of a hierarchically organized novel hollow closed-pore silica antireflective coating (CHAR) with tailored optical properties and a mechanical reliability is of great interest in the field of solar photovoltaic technology. The process mainly contains two aspects: (1) a styrene–acrylate emulsion @ organic–inorganic silica precursor (SA@OISP) core/shell hierarchical nanostructure, consisting of a sacrificial styrene–acrylate (SA) primary template, was fabricated using a sol–gel method; (2) the self-assembly of the nanostructures leads to SA@OISP nanospheres forming the high-quality hollow closed-pore silica antireflection coating (CHAR) by a dip-coating process and a subsequent calcination treatment. The resulting SA@OISP nanospheres have a mean diameter of 65.2 nm and contained a SA soft core with a mean diameter of approximately 54.8 nm and an organic–inorganic silica precursor (OISP) shell with a thickness of approximately 6–10 nm. Furthermore, t...
TL;DR: The results obtained in this work show that the use of Cu as a dopant in ZnO films processed by sol-gel produces excellent catalysts for sensing C3H8 gas.
Abstract: A study on the propane gas-sensing properties of Cu-doped ZnO thin films is presented in this work. The films were deposited on glass substrates by sol-gel and dip coating methods, using zinc acetate as a zinc precursor, copper acetate and copper chloride as precursors for doping. For higher sensitivity values, two film thickness values are controlled by the six and eight dippings, whereas for doping, three dippings were used, irrespective of the Cu precursor. The film structure was analyzed by X-ray diffractometry, and the analysis of the surface morphology and film composition was made through scanning electron microscopy (SEM) and secondary ion mass spectroscopy (SIMS), respectively. The sensing properties of Cu-doped ZnO thin films were then characterized in a propane atmosphere, C3H8, at different concentration levels and different operation temperatures of 100, 200 and 300 °C. Cu-doped ZnO films doped with copper chloride presented the highest sensitivity of approximately 6 × 104, confirming a strong dependence on the dopant precursor type. The results obtained in this work show that the use of Cu as a dopant in ZnO films processed by sol-gel produces excellent catalysts for sensing C3H8 gas.