Thin Films of Europium (III) Doped-TiO2 Prepared by Electrophoretic Deposition from Nanoparticulate Sols

2012 ◽  
Vol 507 ◽  
pp. 73-77 ◽  
Author(s):  
Mario Borlaf ◽  
Maria Teresa Colomer ◽  
Howard Titzel ◽  
James H. Dickerson ◽  
Rodrigo Moreno
Keyword(s):  
Thin Films ◽  
Zeta Potential ◽  
Electrophoretic Deposition ◽  
Colloidal Stability ◽  
Sol Gel ◽  
Complete Characterization ◽  
Constant Current ◽  
Molar Ratio ◽  
Versatile Technique ◽  
The Stability

Colloidal sol-gel is a common method used for the preparation of stable and homogeneous sols and thin films. The nanoparticulate sols can be easily deposited by EPD, which is a versatile technique for producing denser and thicker coatings than those produced by other techniques like dipping. A complete characterization of the sols, such as colloidal stability and electrophoretic mobility, which can be determined through zeta potential measurements, as well as the influence of deflocculants in the surface properties, is needed before using electrophoretic deposition. In this work, we have prepared sols of TiO2with an alkoxide:water molar ratio of 50:1 and Eu (III) doped-TiO2(2 mole % Eu (III)) using as precursors titanium (IV) isopropoxide and europium (III) acetate hydrate, respectively. The stability of the particulate sols was studied in terms of conductivity, zeta potential and viscosity evolution. Anatase stable sols, after peptization and without the use of any additive, were deposited on stainless steel substrates by electrophoretic deposition under both constant current and constant voltage conditions. Using different intensities and deposition times we have obtained thin films with different features (thicknesses and morphology) and different optical properties. The presence of europium (III) increases particle size, viscosity and peptization time and decreases the band gap of TiO2.

scholarly journals Effect of Tris and acetic acid on the stability of titania nanoparticles in different alcohols and their electrophoretic deposition process

2018 ◽  
Vol 12 (1) ◽  
pp. 56-65 ◽  
Author(s):  
Morteza Farrokhi-Rad
Keyword(s):  
Acetic Acid ◽  
Zeta Potential ◽  
Electrophoretic Deposition ◽  
Colloidal Stability ◽  
Optimum Concentration ◽  
Titania Nanoparticles ◽  
Potential Measurement ◽  
The Stability ◽  
Kinetics Of ◽  
Titania Coating

Tris (tris(hydroxymethyl)aminomethane) was used as the dispersant to enhance the colloidal stability of titania nanoparticles in different alcohols (methanol, ethanol, isopropanol and butanol). Acetic acid (AA) was also used to increase the ionization of Tris via acid-base reaction. The effect of Tris on the stability of suspensions in the absence as well as the presence of AA was investigated by different analysis, such as conductivity and zeta potential measurement as well as FTIR analysis. It was found that Tris is protonated and adsorbed on the titania nanoparticles. It enhances their zeta potential and thus colloidal stability. The optimum concentration of Tris increased with molecular weight of alcohol (0.1, 0.2, 0.3 and 0.6 g/l for methanolic, ethanolic, isopropanolic and butanolic suspensions, respectively). The optimum concentration of Tris decreased to 0.1 g/ l for all AA containing suspensions except the methanolic ones. Titania coating was obtained by electrophoretic deposition (EPD) performed at 60 V. The current density and in-situ kinetics of deposition were recorded during EPD. It was found that the kinetics of EPD is the fastest for the suspensions with the optimum concentration of Tris (the highest zeta potential). Calcium phosphate phases were formed on the surface of titania coating after its immersion for one week in SBF at 37.5?C.

Sol-gel synthesis and characterization of Ag nanoparticles in ZrO2 thin films

2009 ◽  
Vol 24 (8) ◽  
pp. 2541-2546 ◽  
Author(s):  
Eisuke Yokoyama ◽  
Hironobu Sakata ◽  
Moriaki Wakaki
Keyword(s):  
Thin Films ◽  
Sol Gel ◽  
Composite Films ◽  
Dip Coating ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Silver Surface ◽  
Molar Ratios ◽  
Sol Gel Synthesis

ZrO2 thin films containing silver nanoparticles were prepared using the sol-gel method with Ag to Zr molar ratios [Ag]/[Zr] = 0.11, 0.25, 0.43, 0.67, 1.00, 1.50, and 2.33. After dip coating on glass substrate, coated films were annealed at 200 and 300 °C in air. X-ray diffraction peaks corresponding to crystalline Ag were observed, but a specific peak corresponding to ZrO2 was not observed. At the molar ratio [Ag]/[Zr] = 0.25, the particle size of Ag distributed broadly centered at 17 nm for an annealing temperature of 200 °C and at 25 nm for 300 °C. The films annealed in air at 200 °C showed an absorption band centered at 450 nm because of the silver surface plasmon resonance, whereas films heated at 300 °C in air caused a red shift of the absorption to 500 nm. The absorption peak was analyzed using the effective dielectric function of Ag-ZrO2 composite films modeled with the Maxwell-Garnett expression.

Compositional Tailored Sol-Gel SiO2–TiO2 Thin Films: Crystallization, Chemical Bonding Configuration, and Optical Properties

2005 ◽  
Vol 20 (11) ◽  
pp. 3141-3149 ◽  
Author(s):  
Li-Lan Yang ◽  
Yi-Sheng Lai ◽  
J.S. Chen ◽  
P.H. Tsai ◽  
C.L. Chen ◽  
...  
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Chemical Bonding ◽  
Rutherford Backscattering Spectrometry ◽  
Incident Angle ◽  
Sol Gel ◽  
Molar Ratio ◽  
Titanium Tetraisopropoxide ◽  
Tio2 Thin Films ◽  
Bonding Configuration

Thin films of SiO2–TiO2 composite oxides with various SiO2:TiO2 compositions were prepared by the sol-gel method, using tetraethylorthosilicate (TEOS) and titanium tetraisopropoxide (TTIP) as precursors. The composition, crystal structure, and chemical bonding configuration of the as-deposited and annealed SiO2–TiO2 thin films were analyzed using Rutherford backscattering spectrometry (RBS), glancing incident angle x-ray diffraction (GIAXRD) and Fourier transform infrared spectroscopy (FTIR), respectively. Optical properties of the films were characterized by spectroscopic ellipsometry and ultraviolet-visible spectrophotometry. The Si/Ti ratios in the SiO2–TiO2 films agree with the TEOS/TTIP molar ratio in the sol-gel precursor. When the TEOS/(TEOS + TTIP) ratio is greater than 40%, the SiO2–TiO2 thin films remain amorphous (without formation of TiO2 crystalline phase) after annealing at temperatures as high as 700 °C. FTIR spectra indicate that the quantity of Si–O–Ti bonding can be maximized when the TEOS:TTIP in the precursor is 80%:20%. The refractive index of the SiO2–TiO2 films increases approximately linearly to the mixing ratio of TTIP/(TEOS + TTIP). However, SiO2-rich films possess higher ultraviolet-visible transmittance than the TiO2-rich films. The modification of microstructure and chemical bonding configuration in the SiO2–TiO2 films by the composition and its influence on the optical properties are discussed.

scholarly journals Sol-gel prepared active ternary oxide coating on titanium in cathodic protection

2007 ◽  
Vol 72 (12) ◽  
pp. 1393-1402 ◽  
Author(s):  
Vladimir Panic ◽  
Branislav Nikolic
Keyword(s):  
Cathodic Protection ◽  
Sol Gel ◽  
Oxide Coating ◽  
Molar Ratio ◽  
Ternary Oxide ◽  
Electrochemical Characteristics ◽  
Accelerated Corrosion ◽  
Metal Chlorides ◽  
Corrosion Stability ◽  
The Stability

The characteristics of a ternary oxide coating, on titanium, which consisted of TiO2, RuO2 and IrO2 in the molar ratio 0.6:0.3:0.1, calculated on the metal atom, were investigated for potential application for cathodic protection in a seawater environment. The oxide coatings on titanium were prepared by the sol-gel procedure from a mixture of inorganic oxide sols, which were obtained by forced hydrolysis of metal chlorides. The morphology of the coating was examined by scanning electron microscopy. The electrochemical properties of activated titanium anodes were investigated by cyclic voltammetry and polarization measurements in a H2SO4- and NaCl-containing electrolyte, as well as in seawater sampled on the Adriatic coast in Tivat, Montenegro. The anode stability during operation in seawater was investigated by the galvanostatic accelerated corrosion stability test. The morphology and electrochemical characteristics of the ternary coating are compared to that of a sol-gel-prepared binary Ti0.6Ru0.4O2 coating. The activity of the ternary coating was similar to that of the binary Ti0.6Ru0.4O2 coating in the investigated solutions. However, the stability in seawater is found to be considerably greater for the ternary coating.

Synthesis and Characterization of Pd/Ag/SiO2 Nano-Composite Materials

2017 ◽  
Vol 726 ◽  
pp. 204-209 ◽  
Author(s):  
Jing Yang ◽  
Bao Song Li ◽  
Zhi Tong ◽  
Rui Hua Mu
Keyword(s):  
Zeta Potential ◽  
Size Distribution ◽  
Sol Gel ◽  
Linear Structure ◽  
Nitrogen Atmosphere ◽  
Molar Ratio ◽  
Powder Materials ◽  
X Ray Diffraction ◽  
Silica Network

Pd/Ag/SiO2 sols and powder materials were prepared by adding AgNO3 and Pd (NO3)2·2H2O into a methyl-modified silica sol. Tetraethylorthosilicate and methyltriethoxysilane were used as the silica precursor for the sol-gel reaction. The obtained SiO2 sols and powder materials were characterized by sol particle size distribution, zeta potential analysis, UV-Vis spectra, Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) measurement. It was found that most of the particle sizes of the prepared Pd/Ag/SiO2 sols are about 2~10 nm with narrow size distribution. The zeta potential of Pd/Ag/SiO2 sol with Pd/Ag molar ratio of 7.5/2.5 presents the highest value. The FTIR analysis substantiates that the Si-CH3 groups exist in the silica network and the formed Pd/Ag/SiO2 sol particles possess linear structure. XRD characterization indicates that the Pd2+ and Ag+ in the Pd/Ag/SiO2 materials had be reduced to Pd0 and Ag0, respectively, after annealed in a nitrogen atmosphere at 350°C.

Photocatalytic Properties of ZnO and Ag Doped ZnO Thin Films

2014 ◽  
Vol 685 ◽  
pp. 3-6
Author(s):  
Ying Lian Wang ◽  
Jun Yao Ye
Keyword(s):  
Thin Films ◽  
Annealing Temperature ◽  
Sol Gel ◽  
Structural Features ◽  
Photocatalytic Properties ◽  
Zno Thin Films ◽  
Molar Ratio ◽  
Zno Films ◽  
Doped Zno ◽  
Excellent Adhesion

Pure ZnO thin films and Ag doped ZnO thin films were prepared on quartz substrates by sol-gel process. Structural features and UV absorption spectrum have been studied by XRD and UV-Vis-Nir scanning spectrophotometer. Taking phenol as pollutants, further study of the effect of different annealing temperature and Ag dopant amount of ZnO films on photocatalytic properties was carried out. The results showed that, the optimal annealing temperature on photocatalytic degradation of phenol in this experiment was 300 °C, the best molar ratio of ZnO and Ag was 30:1, which was better than pure ZnO film greatly. Excellent adhesion, recyclable and efficient degradation Ag doped ZnO thin films were found in this experiment.

Effect of Water on the IR Properties of Mg2+ Intercalated Electrochromic Nb2O5 Thin Films

2006 ◽  
Vol 972 ◽  
Author(s):  
Gargi Agarwal ◽  
G B Reddy
Keyword(s):  
Thin Films ◽  
Aqueous Solution ◽  
Water Content ◽  
Current Density ◽  
Sol Gel ◽  
Constant Current ◽  
Cyclic Stability ◽  
Constant Current Density ◽  
Effect Of Water ◽  
Ftir Studies

AbstractSol-gel derived Nb2O5 thin films were intercalated with Mg2+,using the non-aqueous solution of Mg(ClO4)2 in propylene carbonate (pc) as the electrolyte. 2% and 4% ( volume %) water was added to the electrolyte to study the effect of water on the electrochromic properties of Nb2O5. This paper presents the changes in optical and structural properties of the intercalated films with and without water in the electrolyte. The ratio (x) of the Mg2+ and Nb atoms has been controlled by optimizing the intercalation duration under a constant current density. The fall in transmittance on intercalation (for x= 0.8) increased by 15% with 4% water in the electrolyte, compared to the film intercalated without water. FTIR studies show that water is incorporated in the films on intercalation and small quantities of Mg(OH)2 and Nb-OH are formed along with Mg-O-Nb bonds. The presence of water in electrolyte decreases water content in the films and enhances the formation of Mg(OH)2, Mg-O-Nb and Nb-OH bonds. The recovery of Mg2+ on deintercalation is slightly reduced in presence of water in the electrolyte. The cyclic stability of the films intercalated without water is more than that of the films intercalated in presence of water.

Fabrication and Stability of CoAl2O4 Ceramic Pigment for 3D Printing

2017 ◽  
Vol 898 ◽  
pp. 1935-1939 ◽  
Author(s):  
Yuan Song ◽  
Yuan Lin Zheng ◽  
Yu Fei Tang ◽  
Hai Bing Yang
Keyword(s):  
Solid Solution ◽  
Aqueous Solution ◽  
3D Printing ◽  
Zeta Potential ◽  
Spinel Structure ◽  
Sol Gel ◽  
Ceramic Pigment ◽  
Ceramic Pigments ◽  
Oxide Solid Solution ◽  
The Stability

Ceramic pigment is the key component of the ink color in the 3D printing process of ceramic products. The color performance and stability of ceramic pigments after calcination still need to be improved. In the present study the cobalt aluminate (CoAl2O4) ceramic pigment powders were fabricated by sol-gel method. The effects of fabrication processes on color properties of CoAl2O4 ceramic pigments were investigated. The compositions and morphologies of CoAl2O4 ceramic pigment powders were characterized. The stability of CoAl2O4 ceramic pigments was discussed. The results showed that the CoAl2O4 ceramic pigment with high chroma was obtained at calcination temperature of 1200°C and the Co/Al ratio is 1:3. The Zeta potential of the fabricated CoAl2O4 ceramic pigment powders in aqueous solution was-66.2 mV, which represented good dispersion stability. The chroma and saturation of the CoAl2O4 ceramic pigment increased owing to that the oxide solid solution in the spinel structure increased after being sintered at 1300 oC.

STUDY ON STABILITY AND RHEOLOGY OF PEG6000/NANO-Ni(OH)2 SOL

2006 ◽  
Vol 05 (06) ◽  
pp. 943-949
Author(s):  
QINGYI PAN ◽  
YAN HUANG ◽  
YAN LI ◽  
ZHIXUAN CHENG ◽  
XIAOWEN DONG
Keyword(s):  
Thin Films ◽  
Spin Coating ◽  
Colloidal Particles ◽  
Colloidal Stability ◽  
Theoretical Foundation ◽  
Sol Gel ◽  
Stable Region ◽  
Interaction Forces ◽  
Spin Coating Method ◽  
Coating Method

The PEG6000/nano- Ni ( OH )2 sol was prepared by modified sol–gel method. The effect of Ac - on Ni ( OH )2 colloidal particles and the structure of PEG6000/nano- Ni ( OH )2 was investigated. The results show that hydrogen bonds or other weak interaction forces between PEG6000 and Ni ( OH )2 can change the zeta potential of the Ni ( OH )2 surface and enhance the colloidal stability of Ni ( OH )2. The stable region of the PEG6000/ Ni ( OH )2 sol was determined by measuring the viscosity. The ratio of PEG6000 to Ni ( OH )2 is the principal factor that influences the flow patterns of the sol. Surfaces of the thin films prepared from Newtonian sol by sol–gel spin-coating method are smooth while those from pseudoplastic sol are rough. The results establish the theoretical foundation for preparing the nano- NiO thin films by spin-coating method.

Preparation and Electrophoretic Deposition of an Yttrium Silicate Precursor Sol

2009 ◽  
Vol 412 ◽  
pp. 267-272 ◽  
Author(s):  
Jana Grosse-Brauckmann ◽  
Günter Borchardt ◽  
Christos Argirusis
Keyword(s):  
Electrophoretic Deposition ◽  
Sol Gel ◽  
Constant Current ◽  
Particle Charge ◽  
Yttrium Silicate ◽  
Micro Cracks ◽  
Sol Gel Process ◽  
Hydrolysis Of ◽  
Controlled Hydrolysis

. In the present work we used the sol-gel process to prepare Y2SiO5 precursor sols suitable for electrophoretic deposition (EPD). The sol synthesis was performed through the controlled hydrolysis of alkoxide solutions of tetraethoxysilane and yttriumoxoisopropoxide. During sol development emphasis was put on characterization of particles size and zeta potential of the formed aggregates. We succeeded in synthesizing a clear sol containing polymeric aggregates with acceptable particle charge. The electrophoretic deposition on glassy carbon or C/C-SiC slabs led to homogenous layers. At low sol concentrations micro cracks in the deposited layers were observed whereas higher concentrations led to thin and dense layers. During constant current EPD a constant voltage was recorded indicating that the deposited layer does not lead to an increase in resistivity in this kind of EPD system.

Sign in / Sign up

Export Citation Format

Share Document