Phase-formation kinetics of xerogel and electrical properties of sol-gel-derived BaxSr1−xTiO3 thin films

1997 ◽  
Vol 12 (5) ◽  
pp. 1327-1334 ◽  
Author(s):  
Soo-Ik Jang ◽  
Byung-Cheul Choi ◽  
Hyun M. Jang
Keyword(s):  
Perovskite Phase ◽  
Sol Gel ◽  
Chelating Agent ◽  
Life Time ◽  
Titanium Isopropoxide ◽  
Hydrolysis Rate ◽  
Relative Dielectric Permittivity ◽  
Strontium Chloride ◽  
Heating Rates ◽  
Enolic Form

Chemically homogeneous BaxSr1−xTiO3 (BST with x = 0.6) multicomponent sol was synthesized using barium oxide, strontium chloride, and Ti-alkoxide (titanium isopropoxide) as starting materials. Acetylacetone (AcAc) was introduced as a chelating agent to reduce a rapid hydrolysis rate of Ti-alkoxide. Analysis of Fourier transform infrared spectroscopy (FTIR) spectra indicated that the stabilization of BST sols was achieved by the chelation of Ti-alkoxide with the enolic form of AcAc. The effective activation energy associated with the formation of perovskite phase from the xerogel was estimated by the differential thermal analysis (DTA) experiment using various heating rates. It is approximately 400 kJ/mol with the Avrami exponent (reaction order) of n = 1, suggesting that the growth of perovskite BST is diffusion-controlled. The calculated half-life time suggests that the minimum temperature for the crystallization which is practically accessible to a real processing is approximately 600 °C. The BST thin film fabricated on the “Pt(150 nm)/Ti(100 nm)/SiO2(100 nm)/Si” substrate exhibited the relative dielectric permittivity of 310 and can be represented by an equivalent circuit consisting of a resistive component originated from the bulk perovskite grain and a parallel RC component resulting from the presence of the grain boundary.

scholarly journals Influence of the synthesis route on the properties of BNBT ceramics

2009 ◽  
Vol 3 (1-2) ◽  
pp. 73-78 ◽  
Author(s):  
Elisa Mercadelli ◽  
Alessandra Sanson ◽  
Claudio Capiani ◽  
Luisa Costa ◽  
Carmen Galassi
Keyword(s):  
Piezoelectric Properties ◽  
Perovskite Phase ◽  
Sol Gel ◽  
Titanium Isopropoxide ◽  
Microstructural Properties ◽  
Barium Acetate ◽  
Mechanical Mixing ◽  
Chemical Route ◽  
Critical Comparison ◽  
Gel Combustion

BNBT (0.94[(Bi0.5Na0.5)TiO3]-0.06BaTiO3) nanopowders were prepared starting from an aqueous solution of inorganic salts (barium acetate, bismuth nitrate, sodium nitrate and titanium isopropoxide) either by the citrate- nitrate sol-gel combustion (SGC) or by spray drying (SD). Their chemical and microstructural properties were compared with the ones of the same system obtained by mechanical mixing of oxides (SSCO). The SD and SGC powders require temperatures 150 and 300?C lower than SSCO powder to form the perovskite phase. The chemical and physical properties of the obtained powders strongly depend on the considered chemical route. Therefore the subsequent sintering step and consequently the microstructure of the obtained ceramics differ significantly. The microstructures as well the piezoelectric properties of the sintered SGC, SD, SSCO samples are investigated and a critical comparison is presented. .

Sol-Gel Synthesis of Solid Solution Based on Cerate-Zirconate Ceramics

2019 ◽  
Vol 290 ◽  
pp. 29-34
Author(s):  
Osman Nafisah ◽  
Abdul Samat Abdullah ◽  
Wan Zuliana Wan Zulkifli ◽  
Mahendra Rao Somalu ◽  
Andanastuti Muchtar ◽  
...  
Keyword(s):  
Perovskite Phase ◽  
Sol Gel ◽  
Chelating Agent ◽  
Reactor System ◽  
Critical Parameters ◽  
Processing Temperature ◽  
Barium Cerate ◽  
Phase Purity ◽  
Calcination Temperatures ◽  
Single Perovskite Phase

Ceramics powders based on cerate-zirconate such as yttrium-doped barium cerate-zirconate, BaCe0.54Zr0.36Y0.1O3 (BCZY) have been used as electrolyte materials for proton-conducting fuel cell (PCFC) application. High purity of the ceramics powders are traditionally prepared by solid state reaction (SSR) method at a high processing temperature (> 1400 °C). Alternatively, sol-gel (SG) technique and high pressure – high temperature (HP-HT) batch wise reactor system using supercritical fluids (SCFs) method are introduced to synthesis the powders at a lower temperature. To achieve the goals in producing the ceramics powders with better properties than SSR method, few critical parameters for both SG and SG assisted SCFs methods are determined. This study reports the effects of different chemical agents (chelating agent and surfactant) in SG method and the effects of pressure and temperature of HP-HT batch wise reactor system using ethanol as solvent on the phase purity and microstructure of the BCZY powders. Chelating agent (triethylenetetramine, TETA) and surfactant (Brij-97) aided to produce a single perovskite phase of BCZY at calcination temperatures of 1100 °C and 950 °C, respectively. On the other hand, a single perovskite phase of BCZY was obtained via SCFs assisted with sol-gel (SG-SCFs) method. The optimum characteristics of BCZY powder was found in the one prepared at P = 2 MPa and T = 150 °C and 200 °C. Particles of the powders produced by SG and SG-SCFs methods are spherical in-shape. As proven, SG method is able to produce better phase purity and homogenize BCZY powder at lower processing temperature that meets criteria to be used as an electrolyte material.

scholarly journals Preparation of (Pb,Ba)TiO3 powders and highly oriented thin films by a sol-gel process

2004 ◽  
Vol 19 (5) ◽  
pp. 1492-1498 ◽  
Author(s):  
Stacey W. Boland ◽  
Suresh C. Pillai ◽  
Wein-Duo Yang ◽  
Sossina M. Haile
Keyword(s):  
Thin Films ◽  
Sol Gel ◽  
Chelating Agent ◽  
Titanium Isopropoxide ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Force Microscopy ◽  
Molar Ratios ◽  
Atomic Force ◽  
Sol Gel Process

Solid solution Pb1-xBaxTiO3, with particular emphasis on Pb0.5Ba0.5TiO3, was prepared using a sol-gel process incorporating lead acetate trihydrate, barium acetate, and titanium isopropoxide as precursors, acetylacetone (2,4 pentanedione) as a chelating agent, and ethylene glycol as a solvent. The synthesis procedure was optimized by systematically varying acetylacetone: Ti and H2O:Ti molar ratios and calcination temperature. The resulting effects on sol and powder properties were studied using thermogravimetric analysis/differential scanning calorimetry, Fourier transform infrared spectroscopy, Brunauer-Emmett-Teller analysis, and x-ray diffraction (XRD). Crystallization of the perovskite structure occurred at a temperature as low as 450 °C. Thin films were prepared by spin coating on (100) MgO. Pyrolysis temperature and heating rate were varied, and the resultant film properties investigated using field-emission scanning electron microscopy, atomic force microscopy, and XRD. Under optimized conditions, highly oriented films were obtained at a crystallization temperature of 600 °C.

scholarly journals Novel and facile synthesis of transparent-monolithic TiO2 gels by sol-gel method based on an esterification reaction

2016 ◽  
Vol 34 (3) ◽  
pp. 633-640 ◽  
Author(s):  
Kais Elghniji ◽  
Zohra Anna-Rabah ◽  
Elimame Elaloui
Keyword(s):  
Acetic Acid ◽  
Anatase Phase ◽  
Sol Gel ◽  
Gelation Time ◽  
Chelating Agent ◽  
Active Role ◽  
Titanium Isopropoxide ◽  
Esterification Reaction ◽  
X Ray Diffraction ◽  
External Water

AbstractTransparent TiO2 monoliths were obtained through a modified sol-gel route from titanium isopropoxide as a precursor. By controlling the hydrolysis of this precursor through the intermediate of esterification reaction between acetic acid and isopropanol at 40 °C, transparent TiO2 xerogel monoliths were obtained. The monoliths prepared by this method were transparent in the wavelengths between 400 nm and 700 nm. Fourier transform infrared (FT-IR) spectroscopy suggested that the acetic acid played also an active role as a chelating agent, forming Ti[(OH)y(OOCCH3)x] less reactive species. Powder X-ray diffraction confirmed the amorphous-to-anatase phase transformation with the formation of unknown Ti-containing complex at 90 °C. Only anatase TiO2 could be observed in the samples calcined at 250 °C and 450 °C. Optical aspects of the gel (transparent-transluscent transformation of monolithic gel) and gelation time were controlled by changing the amount of external water.

Photo-Degradation of Acid Red 18 by Using TiO2/SO42- Nanoparticles under UV Light

2012 ◽  
Vol 189 ◽  
pp. 52-57 ◽  
Author(s):  
Jian Feng Wang ◽  
Jin Hai Zhao ◽  
Xue Xue Liu ◽  
Shou Heng Zhang ◽  
Dong Yan Wei ◽  
...  
Keyword(s):  
Uv Light ◽  
Irradiation Time ◽  
Sol Gel ◽  
Pure Titanium ◽  
Titanium Isopropoxide ◽  
Hydrolysis Rate ◽  
Bet Surface Area ◽  
Solution Ph ◽  
Photo Degradation ◽  
Degradation Temperature

Photocatalyst TiO2/SO42- nanoparticles were synthesized by sol-gel method via hydrolysis of pure titanium isopropoxide in n-propanol and acetylacetone solution. The hydrolysis rate and condensation rate of titanium isopropoxide were controlled by concentrated sulfuric acid. Its catalytic activities on the photo-degradation of acid red 18 which is acid azo dyes were studied experimentally and theoretically. The catalysts were characterized by XRD (X-ray diffraction), IR (infrared radiation), BET surface area and SEM (scanning electron microscope). The effects of various catalytic degradation factors of nanocrystalline TiO2/SO42- were discussed in the present paper, which included solution pH, initial concentration of acid red 18, UV irradiation time and the reaction temperature. The results showed that the photo-catalytic activity of this material was obvious significantly when pH is 7.0; degradation temperature is 25 °C and irradiation time is 90 minutes for different concentration acid red 18 solutions.

Comparison of Titanium Precursors in the Sol-Gel Synthesis of Pb0.5Ba0.5TiO3 Powders and Thin Films

2003 ◽  
Vol 784 ◽  
Author(s):  
Stacey W. Boland ◽  
Sossina M. Haile
Keyword(s):  
Thin Films ◽  
Pyrolysis Temperature ◽  
Sol Gel ◽  
Lead Nitrate ◽  
Chelating Agent ◽  
Precursor Chemistry ◽  
Titanium Isopropoxide ◽  
Ferroelectric Material ◽  
Titanium Butoxide ◽  
Sol Gel Synthesis

ABSTRACTTwo sol-gel processes for producing Pb1-xBaxTiO3 (PBT), a ferroelectric material of interest for sensor and actuator applications, are investigated. Each system incorporates lead nitrate and barium acetate as metal sources and ethylene glycol as a solvent. Diethanolamine is used as a chelating agent for titanium isopropoxide or titanium butoxide. Precursor chemistry was systematically varied and the resulting sols and powders were studied using TGA/DSC, FTIR, and XRD. Thin films were prepared using both precursor sources by spin coating onto single crystal (100) MgO. Spin speed and pyrolysis temperature were optimized to produce oriented thin films with thicknesses of up to approximately 500nm. Sols incorporating titanium isopropoxide and a large excess of diethanolamine were particularly stable against hydrolysis.

Parametric Optimization of a Sol-Gel Process for the Synthesis of Highly-Oriented (Pb, Ba)TiO3 Thin Films

2002 ◽  
Vol 748 ◽  
Author(s):  
Wein-Duo Yang ◽  
Suresh C. Pillai ◽  
Stacey W. Boland ◽  
Sossina M. Haile
Keyword(s):  
Thin Films ◽  
Sol Gel ◽  
Chelating Agent ◽  
Titanium Isopropoxide ◽  
X Ray Diffraction ◽  
Film Properties ◽  
Lead Acetate Trihydrate ◽  
Acetate Trihydrate ◽  
Sol Gel Process ◽  
Optimized Conditions

ABSTRACTA sol-gel process incorporating lead acetate trihydrate, barium acetate and titanium isopropoxide as precursors, acetylacetone as a chelating agent, and ethylene glycol as a solvent was used to prepare solid solution (Pb0.5,Ba0.5)TiO3. Water content, annealing temperature and heating rate were varied and the resulting effects on material properties were studied using TGA/DSC, FTIR, FESEM and X-ray diffraction. Crystallization of the perovskite structure occurred at a temperature as low as 450°C. Thin films were prepared by spin coating on (100) MgO using the optimized precursor sol. Pyrolysis and anneal temperatures were varied and the resultant film properties investigated. The pyrolysis temperature used to dry the film was found to strongly affect orientation. Under optimized conditions, highly oriented films were obtained at a crystallization temperature of 600°C.

Synthesis and Properties of Highly Oriented Lead Barium Titanate Thin Film on MgO(100) by a Nonaqueous Sol-Gel Process

2012 ◽  
Vol 581-582 ◽  
pp. 514-518
Author(s):  
Hong Zhu ◽  
Zhi Jun Guo ◽  
Wein Duo Yang ◽  
Wein Feng Chang
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Optical Properties ◽  
Barium Titanate ◽  
Spin Coating ◽  
Sol Gel ◽  
Chelating Agent ◽  
Titanium Isopropoxide ◽  
Ultraviolet Region ◽  
Sol Gel Process

This study investigated the structure, microstructure and optical properties of the highly-oriented lead barium titanate (Pb1-xBaxTiO3, PBT) thin films prepared on MgO (100) substrate by a nonaqueous sol-gel process. The film precursor was synthesized by the modified sol-gel processing from lead acetate, barium acetate, and titanium isopropoxide, acetylacetone as chelating agent, and ethylene glycol as solvent. This stable precursor was formed by acetylacetone chelating with titanium isopropoxide and then mixing the solution of the acetates. The spin-coating technique was used to deposit the PBT films on MgO (100) substrate with different barium contents and various spin-coating numbers, respectively. X-ray diffraction was employed to study the crystal structure of the thin film and field emission scanning electron microscopy was used to characterize the microstructure of the films. Optical properties of the thin films were investigated by Ultraviolet-visible spectrophotometer. All films exhibited a (100) preferred orientation, especially the PB0.5T (3-coating layers) thin film. In the optical properties, the adsorption wavelength shifted to the ultraviolet region with increasing barium.

A Matrix Acidizing System for Controlled Carbonate Well Stimulation using a Carboxylic Acid Salt with a Chelating Agent

2021 ◽  
Author(s):  
Albert Bokkers ◽  
Piter Brandenburg ◽  
Coert Van Lare ◽  
Cees Kooijman ◽  
Arjan Schutte
Keyword(s):  
Chelating Agent ◽  
Life Time ◽  
Nitrogen Atmosphere ◽  
Injection Rate ◽  
Sodium Gluconate ◽  
Matrix Acidizing ◽  
Well Stimulation ◽  
Stirred Reactor ◽  
Core Flood ◽  
Optimum Injection Rate

Abstract This work presents a matrix acidizing formulation which comprises a salt of monochloroacetic acid giving a delayed acidification and a chelating agent to prevent precipitation of a calcium salt. Results of dissolution capacity, core flood test and corrosion inhibition are presented and are compared to performance of 15 wt% emulsified HCl. Dissolution capacity tests were performed in a stirred reactor at atmospheric pressure using equimolar amounts of the crushed limestone and dolomites. Four different chelating agents were added to test the calcium ion sequestering power. Corrosion tests were executed using an autoclave reactor under nitrogen atmosphere at 10 barg. Core flood tests were performed to simulate carbonate matrix stimulation using limestone cores. It was found that the half-life time of the hydrolysis reaction is 77 min at a temperature of 100 °C. Sodium gluconate and the sodium salt of D-glucoheptonic acid were identified to successfully prevent the precipitation of the reaction product calcium glycolate at a temperature of 40 °C. Computed Tomography (CT) scans of the treated cores at optimum injection rate showed a single wormhole formed. At 150 °C an optimum injection rate of 1 ml/min was found which corresponds to a minimum PVBT of 6. In addition, no face dissolution was observed after coreflooding. Furthermore, the corrosion rates of different metallurgies (L80 and J55) were measured which are significantly less than data reported in literature for 15wt% emulsified HCl. The novelty of this formulation is that it slowly releases an organic acid in the well allowing deeper penetration in the formation and sodium gluconate prevents precipitation of the reaction product. The corrosivity of this formulation is relatively low saving maintenance costs to installations and pipe work. The active ingredient in the formulation is a solid, allowing onsite preparation of the acidizing fluid.

Degradation of pharmaceutical antibiotic (ciprofloxacin) by photocatalysis process using sol-gel based titanium dioxide nanoparticles

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Nitesh Parmar ◽  
Jitendra Kumar Srivastava
Keyword(s):  
Aqueous Solution ◽  
Titanium Dioxide Nanoparticles ◽  
Sol Gel ◽  
Operating Cost ◽  
Titanium Isopropoxide ◽  
Photocatalytic Process ◽  
Photocatalytic Reactor ◽  
Prepared Material ◽  
Maximum Removal

Abstract This study is an attempt to the removal of Ciprofloxacin (CIP) antibiotic from simulated wastewater using a photocatalytic process. The photocatalytic process was carried out in a photocatalytic reactor in the presence of TiO2 nanoparticles. TiO2 nanoparticles were successfully prepared in a laboratory scale using sol-gel method with titanium-isopropoxide (TTIP) as titanium precursor. Prepared material was found very effective to the removal of CIP antibiotic. The maximum removal efficiency of 87.95% of ciprofloxacin from aqueous solution was achieved at the pH 5, catalyst doze of 40 mg L−1 with initial concentration of ciprofloxacin 5 mg L−1, and the reaction time of 100 min additionally; material characterization of TiO2 was presented in detail in terms of XRD, SEM, UV, and FTIR. It has been found that at the optimum condition the total operating cost indicated for the removal of ciprofloxacin from aqueous solution is 786.56 (INR/kg of CIP removal). This technique demonstrated that photocatalytic reaction in presence of TiO2 nanoparticles is well applicable to treat pharmaceutical wastewater.

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