Preparation of ZrO2 Spherical Nanoparticles Used for Photonic Crystal

2011 ◽  
Vol 412 ◽  
pp. 57-60 ◽  
Author(s):  
Xiao Qiang Wang ◽  
Meng Wang ◽  
Xiao Yan Zhu ◽  
Ming Ya Li
Keyword(s):  
Photonic Crystal ◽  
Sol Gel ◽  
Three Dimensional ◽  
Phase Reaction ◽  
Size Distributions ◽  
Spherical Nanoparticles ◽  
X Ray Diffraction ◽  
X Ray ◽  
Pore Size Distributions ◽  
Structure Morphology

ZrO2 spherical nanoparticles were prepared by rheological phase reaction. The crystal structure, morphology and formation mechanism were characterized with X-ray diffraction (XRD), Fourier transform infrared spectrum (FTIR) and scanning electron microscopy (SEM), etc. Then three-dimensional photonic crystal was synthesized by sol-gel method and using surfactant as template. The study showed that well-controlled spherical particle is helpful to preparation of photonic crystal with adjustable apertures. Mesoporous ZrO2 was obtained with narrow pore size distributions.

Controlled Fabrication and Properties of Ce0.5Zr0.5O 2 Solid Solutions

2011 ◽  
Vol 295-297 ◽  
pp. 1414-1417
Author(s):  
Zhi Fang Zhang ◽  
Fang Yan Du ◽  
Xiang Rong Ma
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Solid Solutions ◽  
Sol Gel ◽  
Size Distributions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Calcination Temperatures ◽  
Transmission Electron ◽  
Pore Size Distributions

The nanocrystals Ce0.5Zr0.5O2 solid solutions with various morphologies and crystal structures have been synthesized via a modified sol-gel method assisted with a template. Aerosol OT and/or ionic liquids ([MMIM]Cl] and [BMIM]Cl]) was used as a template. The characterization results of the X-ray diffraction, transmission electron microscopy and N2 adsorption at 77 K indicate that the physical properties of the solid solutions were significantly affected by the templates used and the calcination temperatures. The Ce0.5Zr0.5O2 calcined at 773 K possessed bimodal mesopores, narrow pore size distributions, and tetragonal phase.

scholarly journals Preparation and morphology of porous SiO2 ceramics derived from fir flour templates

2010 ◽  
Vol 75 (3) ◽  
pp. 385-394 ◽  
Author(s):  
Li Zhong ◽  
Tiejun Shi ◽  
Liying Guo
Keyword(s):  
Amorphous Material ◽  
Sol Gel ◽  
Size Distributions ◽  
X Ray Diffraction ◽  
Ordered Structures ◽  
Porous Sio2 ◽  
Pore Size Distributions ◽  
Naoh Solution ◽  
Gel Processing ◽  
Highly Porous

The preparation of SiO2 ceramics with controllable porous structure from fir flour templates via sol-gel processing was investigated. The specific size the fir flour, which was treated with 20 % NaOH solution, was infiltrated with a low viscous silica sol and subsequently calcined in air, which resulted in the formation of highly porous SiO2 ceramics. X-Ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and field emission scanning electron microscopy (FESEM) were employed to investigate the microstructure and phase formation during processing as well as of the SiO2 ceramics. N2 adsorption measurements were used to analyze the pore size distributions (PSD) of the final ceramics. The results indicated that the surface topography was changed and the proportion of the amorphous material was increased in NaOH-treated fir flour. The final oxide products retained ordered structures of the pores and showed unique pore sizes and distributions with hierarchy on the nanoscale derived from the fir flour.

Fabrication of Porous LSCF-SDC Carbonates Composite Cathode for Solid Oxide Fuel Cell (SOFC) Applications

2011 ◽  
Vol 471-472 ◽  
pp. 179-184 ◽  
Author(s):  
Raharjo Jarot ◽  
Andanastuti Muchtar ◽  
Wan Ramli Wan Daud ◽  
Norhamidi Muhamad ◽  
Edy Herianto Majlan
Keyword(s):  
Thermal Expansion ◽  
Sol Gel ◽  
Composite Cathode ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structure Morphology ◽  
Composite Cathodes ◽  
Gel Technique ◽  
Optimum Porosity ◽  
Cold Pressed

Composite cathodes made of perovskite La0.6Sr0.4Co0.2Fe0.8O3 (LSCF) and SDC carbonates (SDC-(Li/Na)2CO3) were investigated in relation to their structure, morphology, thermal expansion coefficient and porosity. As a first step, the LSCF powder was prepared by sol-gel technique. This was followed by the preparation of the LSCF-SDC carbonates composite cathode by mixing the LSCF with SDC-(Li/Na)2CO3 electrolyte via solid state reaction in various compositions, i.e. 30, 40 and 50 wt.%, namely 70LSCF-30SDC7030, 60LSCF-40SDC7030 and 50LSCF-50SDC7030, respectively. The powder mixtures were then calcined at 680oC. The resultant powder was fine with surface area of about 3.39-7.42 m2/g and particle size of 0.56-0.66µm. The powder consists of two distinct phases, i.e. LSCF and SDC-(Li/Na)2CO3 as confirmed with x-ray diffraction. The microstructures were observed under scanning electron microscopy (SEM). Increasing the amount of the SDC-(Li/Na)2CO3 electrolyte in the composite cathode was found to bring the thermal expansion of the cathode closer to that of the electrolyte. The cathode pellets were later compacted at different pressures (27, 32 and 37 MPa) and sintered at 600oC. The optimum porosity (20.99-24.98%) was achieved for samples with SDC-(Li/Na)2CO3 content of 30-50% sintered at 600oC and cold pressed at 37 MPa.

Ferroelectric PTCR Films for Photonic Crystal Gas Sensor

2006 ◽  
Vol 952 ◽  
Author(s):  
J. RaviPrakash ◽  
Susan Trolier-McKinstry ◽  
Jing-Gong Cheng ◽  
Mark McNeal ◽  
Anton Greenwald ◽  
...  
Keyword(s):  
Photonic Crystal ◽  
Electric Fields ◽  
Remanent Polarization ◽  
Sol Gel ◽  
Mems Devices ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ptcr Effect ◽  
La Doped ◽  
Room Temperature Dielectric Constant

ABSTRACTWe examined lanthanum doped lead barium titanate films for temperature measurements of photonic crystal - MEMS devices. Films were deposited by sol-gel techniques and crystallized in air above 650°C. X-ray diffraction spectra consistent with the perovskite structure were detected. The room temperature dielectric constant was ∼570 at 10 kHz of La-doped (0.3 mol%) Pb0.3Ba0.7TiO3 films. These films had a remanent polarization of ∼20μC/cm2 and a coercive field of 145 kV/cm. The leakage current density was ∼ 2×10−7 amps/cm2 at 100 kV/cm field. The resistivity of the films extracted from the linear region of the I-V data (electric fields in excess of 100 kV/cm) measured as a function of temperature shows an increase in resistivity at temperatures above Tc (120°C for BaTiO3 and 240°C for Pb0.3Ba0.7TiO3) of the film consistent with positive coefficient of resistance (PTCR) effect. However, the change in resistance was small when compared to bulk samples of similar compositions.

Crystal Growth and Photoluminescence Properties of Truncated Cubic BaMgAl10O17:Eu2+ Phosphors for Three-Dimensional Plasma Display Panels

2016 ◽  
Vol 16 (4) ◽  
pp. 3869-3872 ◽  
Author(s):  
Bitao Liu ◽  
Yuan Chen ◽  
Lingling Peng ◽  
Tao Han ◽  
Hong Yu ◽  
...  
Keyword(s):  
Crystal Growth ◽  
Sinter Process ◽  
Sol Gel ◽  
Three Dimensional ◽  
Photoluminescence Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Plasma Display Panels ◽  
Sol Gel Process ◽  
Plasma Display

Monodispersed, truncated cube BaMgAl10O17:Eu2+ phosphors were synthesized by the sol–gel process. Scanning electron microscope (SEM), photoluminescence spectrum, powder X-ray diffraction and decay curves were used to evaluate the truncated cubic BaMgAl10O17:Eu2+ phosphors. The crystal growth process and photoluminescence properties were discussed in detail. The results showed that this truncated cubic morphology can be achieved via a simple sinter process. These truncated cubic BaMgAl10O17:Eu2+ phosphors showed acceptable emission intensity and better thermal properties. This result indicates truncated cubic BaMgAl10O17:Eu2+ phosphors would meet the requirements of plasma display panels (PDPs).

Preparation and Optical Properties of CuS Nanofilms by a Facile Two-Step Process

2017 ◽  
Vol 16 (01) ◽  
pp. 1650021 ◽  
Author(s):  
Zhankui Cui ◽  
Junqiang Zhou ◽  
Suxiang Ge ◽  
Hongxiao Zhao
Keyword(s):  
Optical Properties ◽  
Gas Phase ◽  
Phase Reaction ◽  
Spherical Nanoparticles ◽  
X Ray Diffraction ◽  
Step Process ◽  
X Ray ◽  
Gas Phase Reaction ◽  
Composition And Structure ◽  
Lower Temperature

CuS nanofilms were prepared by a facile two-step process including chemical bath deposition of Cu nanofilms first and the subsequent thermal sulfuration step. The composition and structure of the samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and Raman spectroscopy. The optical properties of CuS nanofilms were determined by Ultraviolet-visible (UV-Vis) technique. The results show that the nanofilms composed by Cu spherical nanoparticles were completely transformed to the nanofilms composed by CuS nanosheets when the sulfuration temperature was 350[Formula: see text]C. The light absorption edges of CuS nanofilms exhibit red shift when sulfuration occurred at lower temperature. A plausible growth mechanism related with gas phase reaction for formation of CuS nanofilms was also proposed.

Using X-Ray Micro-CT Imaging to Monitor Dissolution of Macroporous Bioactive Glass Scaffolds

2005 ◽  
Vol 284-286 ◽  
pp. 493-496 ◽  
Author(s):  
Julian R. Jones ◽  
Georgina E. Milroy ◽  
Ruth Cameron ◽  
William Bonfield ◽  
Larry L. Hench
Keyword(s):  
Bioactive Glass ◽  
Sol Gel ◽  
Size Distributions ◽  
Micro Ct ◽  
X Ray ◽  
Pore Size Distributions ◽  
Icp Analysis ◽  
Non Destructive ◽  
Interconnected Pore ◽  
Percentage Porosity

Bioactive glass scaffolds with interconnected macroporous networks have been developed by foaming sol-gel derived bioactive glass of the 70S30C (70 mol% SiO2, 30 mol% CaO) composition. The effect of sintering temperature on the dissolution of the scaffolds in simulated body fluid (SBF) was investigated in 3D using x-ray micro-computer tomography (micro CT) and inductive coupled plasma (ICP) analysis. Micro-CT is non-destructive and allows observation of specific parts of the scaffold at various stages of degradation. However, data analysis is complex at present. Percentage porosity data obtained by micro-CT was compared to physical data and pore size distributions obtained from mercury intrusion porosimetry were compared to the interconnected pore diameters observed from the micro CT images.

Synthesis and Characterization of Nickel-Based Monolithic Aerogel via Sol-Gel Method

2011 ◽  
Vol 335-336 ◽  
pp. 368-371 ◽  
Author(s):  
Yu Tie Bi ◽  
Hong Bo Ren ◽  
Bo Wei Chen ◽  
Lin Zhang
Keyword(s):  
Electron Microscopy ◽  
Polyacrylic Acid ◽  
Sol Gel ◽  
Three Dimensional ◽  
Synthesis And Characterization ◽  
X Ray Diffraction ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method

The synthesis and characterization of nickel-based aerogel prepared using nickel chloride as the precursor via sol-gel method is described. The addition of the polyacrylic acid as an template to the solution of NiCl2•6H2O can guide the gelation in the reaction to build a three dimensional open structure. The aerogel has been characterized using field emission scanning electron microscopy (FESEM), highresolution transmission electron microscopy (HRTEM), nitrogen adsorption desorption analysis and powder X-ray diffraction (XRD). The results indicate that the nickel-based aerogel has a typical three dimensional structure made up of spherical particles with an open porous network and has high surface area about 192 m2/g, average pore diameter about 40nm. The X-ray diffraction (XRD) patterns show that the aerogel prepared at room temperature belongs to amorphous material. The synthesis of nickel-based aerogel, using polyacrylic acid as an template, is especially unique in our experiment.

scholarly journals Effect of Eu3+ Concentration on the BaAl2O4/CaAl4O7: x% Eu3+ (0 ≤ x ≤ 5.5) Mixed-Phase Nanophosphors Synthesized Using Citrate Sol-Gel Method

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Bamba Mahman ◽  
Mpho Enoch Sithole
Keyword(s):  
Electron Microscopy ◽  
Sol Gel ◽  
Mixed Phase ◽  
Nanometer Scale ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Structure Morphology ◽  
Crystallite Sizes ◽  
Gel Technique

A series of undoped mixed-phase BaAl2O4/CaAl4O7 (hereafter called BC) and doped BC: x% Eu3+ (0 < x ≤ 5.5) nanophosphors were successfully prepared by the citrate sol-gel technique. Their structure, morphology, and optical properties were studied in detail by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and photoluminescence (PL) spectroscopy. XRD and SEM showed that all the BC:x% Eu3+ samples consisted of the crystalline structure of the mixed phases of both the BaAl2O4 and CaAl4O7 materials. The structure resembles more that of the BaAl2O4 than the CaAl4O7 phase. The TEM results suggest that the crystallite sizes are in the nanometer scale with rod-like particles. PL results showed multiple emission peaks located at 436, 590, 616, 656, and 703 nm, which were assigned to the intrinsic defects within the BC matrix, 5D0 ⟶ 7F1, 5D0 ⟶ 7F2, 5D0 ⟶ 7F3, and 5D0 ⟶ 7F4 transitions of Eu3+, respectively. The decay curves evidently showed that the nanophosphors have persistent luminescence. The Commission Internationale de l’Eclairage (CIE) analysis revealed that doping has tuned the emission colour from blue to orange-red. The results indicate that the Eu3+-doped samples can potentially be used in the orange/red-emitting phosphors.

scholarly journals Catalytic Activity of Srilankite Nanoparticles in the Esterification of Oleic Acid

2020 ◽  
Author(s):  
Roberto Berrones-Hernández ◽  
Gerardo Trejo-Hernández ◽  
Yolanda del Carmen Pérez-Luna ◽  
Yazmin Sánchez-Roque ◽  
Lizeth Rojas-Blanco ◽  
...  
Keyword(s):  
Oleic Acid ◽  
Sol Gel ◽  
Esterification Reaction ◽  
Impregnation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Tio2 Anatase ◽  
Structure Morphology ◽  
Sol Gel Process ◽  
Maximum Conversion

This work shows the results obtained in the synthesis of srilankite nanoparticles, (Zr, Ti)O2, and TiO2 anatase, both catalysts presented an admix of phases, anatase/rutile, and srilankite/rutile, respectively. Their performance in the production of biodiesel through the esterification of oleic acid was evaluated. The catalysts were obtained using the sol-gel process and sulfated via the impregnation method. The samples were characterized using X-ray diffraction (XRD), scan electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS) and Fourier-Transform Infrared Spectroscopy (FTIR) to analyze the properties in its crystalline structure, morphology, and chemical composition. Its efficiency during the esterification reaction was measured based on the decrease in free fatty acids (FFA). FFA, oleic acid was added at different weight percentages (1%, 3%, and 5% w/w). The time of reaction was 6 hours at 55 &deg;C and the catalyst with better performance was the sulfated Srilankite/rutile, reaching a maximum conversion of up to 90%.

Sign in / Sign up

Export Citation Format

Share Document