Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : sol


Gas Sensitivity of ITO Composite Prepared by Sol-Gel Method

R. J . Halbos; S. AL-Algawi; R.T. Rasheed

Engineering and Technology Journal, 2017, Volume 35, Issue 10, Pages 981-986
DOI: 10.30684/etj.35.10A.3

Indium oxide and indium tin oxide composite (ITO) were prepared by sol-gel dip-coating (SGDC) technique. The particles annealed at (200 ◦C, 400 ◦C). The structure and surface morphology of particles were characterized by X-ray diffraction (XRD), Atomic Force Microscope (AFM), FT-IR and UV/visible measurements. The XRD and AFM indicate decreasing in the particle size and improve of optical and electrical properties of composite with increasing of tin oxide addition. The hall measurement were used to obtain information about the type of conductivity of indium oxide and indium tin oxide thin films and carrier concentration and mobility and resistivity, the results of Hall measurements show that the In2O3 and ITO composite have n-type. The thin film of composite ITO at composition (80:20) mole ratio has high sensitivity toward CO gas compared with pure indium oxide.

Synthesis of Dopant Zno Thin Films with Al Using Dip Coating for Gas Sensors

S.H. Sabeeh; R.H. Jassam

Engineering and Technology Journal, 2017, Volume 35, Issue 8, Pages 842-844
DOI: 10.30684/etj.35.8A.9

The sol-gel technique (dip coating method) used to synthesize pure Zinc Oxide and Aluminum doped Zinc Oxide thin films on glass substrate for gas sensing application. Zinc acetate dehydrate was used as source of Zinc ions. The influence of annealing temperature of pure ZnO thin films with three different temperatures (300,400,and 500 ) °C, Aluminum dopant concentration with two different concentration (3wt% and 5wt% ) and annealing temperature for AZO thin films with three different temperatures (300,400,and 500 ) °C on gas sensing properties was studied. The results show that ZnO was to be sensitive toward CO gas and its sensitivity decrease with increase in annealing temperature of pure ZnO and (5wt.%) AZO thin films. It is found that the sensitivity of pure ZnO thin films decrease from 67% at 300 °C to 54% and 38% at 400 and 500 °C respectively. Likewise, for 5wt. % AZO thin film the sensitivity improved by increase the Aluminum dopant concentration with fixed annealing temperature 500 °C. It is found that the sensitivity increase form 49% to 57% when doped with Al at (3 wt. %) and (5 wt. %) respectively.

Synthesis of Magnetic MWCNTs Nanohybrids and Application in Remediation of Chromium Ions in Refinery Wastewater

A. M. ALI

Engineering and Technology Journal, 2017, Volume 35, Issue 8, Pages 838-841
DOI: 10.30684/etj.35.8A.8

This study presents the preparation of Magnetic - Multiwall Carbon Nanotubes (M-MWCNTs) as adsorbents, MWCNTs/Fe3O4 nanocomposite, in which multiwall carbon nanotubes were coated to magnetic Fe3O4 particles by simplistic sol-gel techniques. The synthesized MWCNTs/Fe3O4 nano-composites were measured via Fourier Transform Infrared spectroscopy (FTIR), X -Ray Diffraction spectrometry (XRD), and Scanning -electron microscopy (SEM). The adsorption behaviors of the MWCNTs/Fe3O4 nanocomposites will be evaluated intended for the elimination of chromium ions in diluted refinery wastewater.

Synthesis of Mullite Powder from Aluminum Nitrate and Precipitated Silica using Sol-Gel Process

Hussein Alaa Jaber

Engineering and Technology Journal, 2016, Volume 34, Issue 8, Pages 1491-1498
DOI: 10.30684/etj.34.8A.2

In this work, a new route for possibility synthesizing high purity submicron size mullite (3A12O3.2SiO2) powder at relatively low temperature. Mullite precursor has been prepared from mixing precipitated silica powder with solution of aluminum nitrate nonahydrate (Al(NO3)3.9H2O) through sol-gel process, in order to obtain composite powder. The formed precursor gel was calcined at temperatures of (1100, 1150, 1200 and 1250)°C for 1 hour. The influence of calcination temperatures of the mullite synthesis was discussed. The microstructure tests of calcined materials were investigated by x-ray diffractometer (XRD), scanning electron microscopy (SEM), and energy dispersive x-ray spectroscopy (EDX). X-ray analysis results identified the mullitization initiated at 1200°C, and the mullite phase was completely formed at 1250°C. The SEM micrographs show the microstructure of mullite powder had been aggregated in the regular and nearly spherical-like appearances with diameters in the range of (100-200) nm.

Characterization of the Structural and Electrical Properties of Transparent Conductive Oxides Prepared by Sol-Gel Method

Ali J Addie; Azhar I Hassan; Saleema S Saad

Engineering and Technology Journal, 2016, Volume 34, Issue 6, Pages 209-216

Nano crystalline powder of the System Cu-Al-O have been prepared by Sol-Gel technique, copper nitrate and aluminum nitrate have adopted as raw materials for the reaction, and subsequently solid state reactions have used to synthesize different compounds and phases at the calcination stage. Effects of calcination temperature and time in the range 800-1100oC and 1hr-6hr respectively have been investigated. XRD results show that the system have a multiphase and it depends on the calcination time and temperature, the higher the temperature and time the higher the percentage of the compound CuAlO2, whereas the SEM microscopy show that the Nano powder have particle size of 40nm, and Raman spectroscopy reveals the presence of Eg and A1g modes which belong to the structure CuAlO2. The work emphasize that the control of the technique parameters could provide high degree of control on the final required phases and structures.

The Effect of Annealing Temperature on Structural & Optical Properties of Nanocrystalline SnO2 Thin Films Prepared by Sol-Gel Technique

Selma M.H. AL-Jawad; Abdulhussain K. Elttayf; Amel S. Sabr

Engineering and Technology Journal, 2016, Volume 34, Issue 4, Pages 490-498
DOI: 10.30684/etj.34.4B.6

In this work, studying the structural and optical Nano crystalline SnO2 thin films grown on cleaned glass substrates by using sol- gel (dip coating) technique. It is worthy to say that the thickness of the deposited film was of the order of (300-400)nm . The films are annealed in air at , 300◦C, 400◦C and 500◦C temperatures for 60 minutes. The films that are analyses by X-ray diffraction (XRD), Scanning electron microscopy (SEM) , atomic force microscopy and optical absorption spectroscopy technique. The size of crystalline was observed, as well as, so as to increase with increasing annealing temperature . XRD analysis reveals that the whole films are polycrystalline with tetragonal structure with preferred orientation of (110),(101),(200) and (211) . The increase of annealing temperature leads to raise the diffraction peaks and decrease of FWHM. The atomic force microscopy (AFM) and Scanning electron microscopy (SEM) results showed that the average grain size was increase with the increase in annealing temperature. Spectra of transmittance and absorbance was recorded at wavelengths range (300-1000)nm .The optical properties showed high transmission at visible regions. The optical band gap energy was found to be (3.5 , 3.75 , 3,87) eV at annealing temperature (300,400,500 )°C respectively.

Experimental Stability and Thermal Characteristics Enhancement Analysis of Water Based Boehmite Nano fluid

Atia; Mohammed Hussein J. Al; Sarah A. Abed

Engineering and Technology Journal, 2015, Volume 33, Issue 7, Pages 1193-1210

In this work attempt was made to formulate water based boehmite (AlOOH) nanofluid in one and two steps methods. Boehmite is the first born alumina phase as prepared by sol gel route using aluminum isopropoxide precursor, exhibit a combination of excellent consistency and dispersibility in water. Plain nanofluids containing boehmite at different concentrations were investigated for colloidal, suspensions and/or dispersions stability and thermal conductivity enhancement. X-ray diffraction analysis, laser diffraction particle size analysis, viscosity, thermal conductivity measurements, TG/DSC thermal analysis and sedimentation balance were used as characterization tools. The results show promising long-term fluid stability and thermal conductivity enhancement relative to starting based fluid following non-linear dependence on particles concentration. The maximum 2.7 times enhancement in thermal conductivity occurred at narrow boehmite concentration range as a result of achieving optimum nanoparticles aggregation level where neither the case of nanoparticles homogenous dispersion nor the case of fully aggregated clusters could retain these enhancements values. This far beyond behavior from Maxwell's model was explained on the basis of the known mechanisms of thermal conductivity enhancement of nanofluids.

Development of NO2 gas sensor using Sn-doped ITO nanoparticles prepared by Sol-Gel method

Saryia D. Al-ALgawi; Rashed T. Rasheed; Sahar Zeyad Tareq

Engineering and Technology Journal, 2015, Volume 33, Issue 6, Pages 984-993

In this work In2O3 and Sn-doped ITO nanoparticles were prepared by sol-gel method and deposited on quartz substrate by dip coating technique at different doping concentration of (5, 10 and 15%). The samples were annealed at 550 oC at constant time (60 min). X-ray analysis confirmed the formation of polycrystalline cubic phase that decreases in crystalline size with increasing doping concentration. The optical properties of Sn-ITO nanostructure thin film were studied. The transmittance was measured in the wavelength range of (300nm to 1100 nm) for all thin films. The sensitivity towards NO2 gas was measured, when In2O3 was doped with Sn at different concentrations.

Judd–Ofelt analysis of Spectroscopic properties of Nd+3:SiO2 Prepared via Sol-Gel

Mohammed. A. Hamza; Majeda A. Ameen; Hanaa M. Yaseen

Engineering and Technology Journal, 2015, Volume 33, Issue 5, Pages 848-855

Doped and undoped nano particular silicate dioxide was prepared via sol–gel method under varying conditions. The optical properties of prepared samples were investigated by a variety of techniques, including X-ray diffraction, UV- Visible spectroscopy, FTIR spectroscopy and fluorescence spectroscopy. The peak of the fluorescence spectrum was recorded at the wavelength around to 1048nm, which it is close to known fluorescence peaks of Nd:YAG crystal in NIR region. A Judd-Ofelt analysis is performed to calculate the spectroscopic properties of Nd3+ions embedded in SiO2 and compare it with spectroscopic properties of Nd:YAG crystal.The conclusions behind this study show that the doped silicate samples have a high peak emission cross-section σp , which gives an acceptable indication in the direction of using Sol-Gel technique to prepare Nd:SiO2 as a solid state laser active medium.

Synthesis and Characterization of TiO2 Nanoparticles via Sol-Gel Method by Pulse Laser Ablation

Adawiya J. Haider; Zainab N. Jameel; Samar Y. Taha

Engineering and Technology Journal, 2015, Volume 33, Issue 5, Pages 761-771

Nanocrystalline titania powder was prepared at room temperature via sol-gel method; using TiCl4 as precursor and absolute ethanol solution. After mixing, the gel solution was formed. Then the sol-gel dried and calcined at different temperatures. The size of the prepared nanoparticles was reduced by Nd-YAG Pulse Laser Ablation (PLA). The characterization of the TiO2 Nanoparticles in two phases was carried out by X-ray Diffraction (XRD) to investigate the phase structure. The Transmission Electron Microscope (TEM) result shows the particle size of nanoparticles after laser ablation less than 10 nm. Scanning Electron Microscopy (SEM) to obtain the surface morphological studies Results showed that anatase was the only phase in titanium oxide powders up to 500 °C, when the calcination increased in the region of 900 °C the phase transformation from anatase to rutile occurred in the TiO2 nanopowders. This paper shows a comparison between two phases of TiO2 Nanoparticles (anatase and rutile). Fourier Transform Infra-Red (FTIR) to study the vibrational frequencies between the bonds of atoms for synthesized TiO2 Nanoparticles. The Crystalline size of TiO2 Nanoparticles obtained was between (15 -70) nm for anatase at 500 °C and rutile at 900 °C. In FTIR analysis, all the peaks observed were around (400-700) cm-1 due to stretching and bending vibrations.

Synthesis of B4C/YTZP Composite Powder and Studying Effect of its Addition on Mechanical Properties of B4C

Fadhil A. Chyad; Mohammed H. AL-Taie; Hussein AlaaJaber

Engineering and Technology Journal, 2014, Volume 32, Issue 5, Pages 1158-1170
DOI: 10.30684/etj.32.5A.7

In this research B4C powder have been coated with yttria stabilized tetragonal zirconia polycrystalline (YTZP) (ZrO2 – 6wt% Y2O3) by using sol-gel method in order to obtain on composite powder (B4C core/ YTZP shell, 1/1 wt%). Zirconium oxychloride (ZrOCl2.8H2O) and yttrium nitrate (Y(NO3)3.6H2O) were used as the precursors for synthesis of the YTZP compound. The coated B4C powder was then used as additive powder to B4C. It was mixed with different percentages for making ceramic–ceramic composite samples. The YTZP weight percentages added to the B4C were in the range (0–12.5) wt%. The samples sintered by using spark plasma sintering technique at 1800 and 1900°C for 5 min. Density and mechanical properties (Vickers microhardness, fracturetoughness and fracturestrength) for the sintered samples were measured. The results show that the best YTZP additions to the B4C that have good mechanical properties were ranged 5 – 7.5 wt%.

Coating of Carbon Fibers With Calcium Phosphate by Sol- Gel Method

Sewench N. Rafeeq; Wafaa A. Husaien; Russel Rushdi Ghanim

Engineering and Technology Journal, 2014, Volume 32, Issue 5, Pages 1117-1128
DOI: 10.30684/etj.32.5A.3

Sol-gel technique has been used to coat carbon fibers with calcium phosphate to improve the esthetic of black carbon fibers as it's biocompatible. To improve bonding between carbon fibers and prepared calcium phosphate powders, the surface of carbon fibers has been treated with para-aminobenzoic acid. The structural tests include: (SEM, XRD, AFM and FTIR). The morphology of the coating layers has been examined by scanning electron microscope (SEM). The crystallized phase composition of coatings has been identified by x-ray diffractometry (XRD). The grain size of dried and heat treated calcium phosphate coat has been estimated by atomic force microscope (AFM) and fourier transform ــ infrared spectroscopy (FTIR) analysis which support and verify the x-ray diffraction findings.

Synthesis and Characterization of Magnesium Ferrite Materials

Sabah Mohammed Ali Ridha; Ghead Khalaf Salman

Engineering and Technology Journal, 2014, Volume 32, Issue 5, Pages 980-989
DOI: 10.30684/etj.32.5B.14

NiZnMg-Ferrite Nano ceramics were prepared by using sol-gel auto combustion method, these ferrites then pelletized and sintered at different temperatures (1000, 1100 and 1200 0C). Ferrite samples showed spinel structure and inherent ‎properties of high electrical resistivity, low electrical losses and high theoretical ‎densities. Therefore, these ferrites have a potential candidate for high frequency applications. The electrical and structural ‎properties of Ni0.7-yZn0.3MgyFe2O4 (where; y= 0, 0.1, 0.2 and 0.3) were studied and that shows an effect of chemical composition ‎on the electrical, structural, and physical properties depending on Mg content in the Ferrite. Chemical phase analysis carried out by x-ray diffraction spectrum ‎confirms the formation of ferrite Nanopowders with size (22.6 nm), and found that the lattice parameters and particle sizes increase, while theoretical density and porosity ‎decreases with increasing of Mg content in the NiZnMg Ferrites. Resistivity of all samples has been measured at temperatures in the range of ‎‎ (300-540 K), which decreases with increasing of temperatures like ‎a semiconductor behavior.

Developing the Alumina Hybrid Sol-Gel Coating for Steel Oxidation Protection at High Temperatures

Atia; Mohammed Hussein J. Al

Engineering and Technology Journal, 2014, Volume 32, Issue 4, Pages 744-758

The use of nano alumina thin film by hybrid sol-gel route to protect steel from high-temperature oxidation is limited due to the low thermal stability of this coat. In this work, study has been conducted to minimize this effect. The chemical compositions of solid gel (xerogel) obtained from normal alumina hybrid sol-gel were thermally varied, and then recombining with water to form the modified coating solutions at constant concentration of 0.25mol/l alumina. Laser diffraction technique has been used to measure the growth of clusters sizes in different modified solutions. X-ray diffraction analysis to characterize the alumina phase's changes as a function of temperatures. Also gravimetric weight change method to determine the oxidation rate of steel before and after coating. The results showed five changes in alumina phase during heating to 9500C, which are similar to that recorded for the natural ore of boehmite, and the partial removal of non stable by-products constituents associated with xerogel has considerable effect on the degree of particles aggregation and agglomeration in solutions. This worked to improve the thermal stability of the coating layer, and show considerable resistance to cracks formation. At 40-50% removal, the oxidation rate of HSLA steel specimens was enhanced by 88 % at 9500C compared to the steel before coating.

Synthesis of TiO2 Nan particles by Using Sol-Gel Method and Its Applications as Antibacterial Agents

Zainab N. Jameel; Adawiya J. Haider; Samar Y. Taha

Engineering and Technology Journal, 2014, Volume 32, Issue 3, Pages 418-426
DOI: 10.30684/etj.32.3B.4

TiO2 nanoparticles were prepared from TiCl4 as a precursor with ethanol solution with 1:10 ratio in ambient atmosphere, without additive. Sol-gel synthesized has been dried and calcined at (550-600)C. The structure, morphology and the particle size of the nanoparticles were investigated by X-ray Diffraction and Scanning Electron Microscopy (SEM). The optical properties were studied by UV-Visible Spectrophotometer. Results showed that the anatase phase was only in titanium dioxide powder up to 500. The average grain size of TiO2 nanoparticles was obtained in the range of (3- 30) nm. The synthesized TiO2 nanoparticles in 10-5 and 10-3 concentrations exhibited superior antibacterial activity with two types of bacteria, Escherichia coli (E-coli) and Staphylococcus aurous respectively. TiO2 nanoparticles are more efficient as antibacterial agents with Staphylococcus aurous as compared with E-coli.

Properties of Nano Thin Film Composed of Nan Crystalline Zro2 Prepared by (SOL - GEL) Method

Kassim Mohammed Sahan; Aqel Mashot Jafar

Engineering and Technology Journal, 2014, Volume 32, Issue 1, Pages 23-32
DOI: 10.30684/etj.32.1B.4

Nano-crystalline ZrO2 was prepared by sol-gel method and deposited on glass substrate by dip-coating technique method in the room temperature. ZrOCl2 was dissolved in a solvent mixture composed of H2O2 and ammonia. The dissolving reaction produced a colorless, transparent peroxozirconium complex solution. The mean nanocrystalline size was about 7.55 nm. The zirconium film thus obtained was transparent 90% with 5.03 eV band gap. Atomic force microscopy (AFM), X-ray diffraction and (UV-Vis) used to determine the properties of the thin film. The as-deposited thin film was of high purity of ZrO2 and good adhesion to the substrate. The annealing was caused crystallization of tetragonal and monoclinic phase present in the zirconia at 550°C in air. The film showed very flat surfaces consisting of nanoparticles with particle size of ranging (2-10 nm).

Synthesis and Studying SomeMechanical Properties of Nanocomposite

Fadhil A. Chyad; Abdul-Raheem K.Abid Ali; Auday A. Mehatlaf

Engineering and Technology Journal, 2013, Volume 31, Issue 7, Pages 1221-1228
DOI: 10.30684/etj.31.7A1

This study aims to synthesis a nanocomposite from Al2O3 – Cr2O3 and studying some of its mechanical properties like microhardness and fracture strength.
X-Ray diffraction patterns shows a good crystallinity of the composite with very sharp and neat peaks. TEM photographs shows the good distribution of the particles which have an average particle size of (3-6 nm). The microhardness is increased with the increasing of sintering temperatures having the height value at 15% chromia while the fracture strength behaves as a bell shape having again the height value at 15% chromia.

Comprehensive Electrochemical Evaluation of Protective Coatings Properties by Sol-Gel Route for Stainless Steel Corrosion

Atia; Mohammed Hussein J. Al

Engineering and Technology Journal, 2013, Volume 31, Issue 4, Pages 71-86
DOI: 10.30684/etj.31.4A.15

Sol gel nano ceramic coatings have been applied on stainless steel to develop their biological characteristics and increase resistance to corrosion and wear. In this work nine electrochemical parameters were calculated, adopted to set a comprehensive evaluation map for protective properties of the coatings obtained based on occurrence degree of cracks, porosity, general and localized corrosion by using d.c. Potentiostate utilized for measuring the polarization curve in 3.5% NaCl solution at 250C for a single alumina layer deposited on stainless steel specimens by the dipping technique from four solutions containing different alumina concentration 0.25, 0.26, 0.61 and 0.93 mole/liter prepared by dissolving aluminum isopropoxide in water, the coats were then heat treated to 6000C. The results showed the possibility of obtaining clear protective properties that facilitate the comparison between the types of thin coatings deposited on the surfaces of the stainless steel by sol gel method.