scholarly journals AMINO AND MERCAPTO-SILICA HYBRID FOR Cd(II) ADSORPTION IN AQUEOUS SOLUTION

2010 ◽  
Vol 9 (2) ◽  
pp. 170-176 ◽  
Author(s):  
Buhani Buhani ◽  
Narsito Narsito ◽  
Nuryono Nuryono ◽  
Eko Sri Kunarti
Keyword(s):  
Silica Gel ◽  
Sol Gel ◽  
Selectivity Coefficient ◽  
Energy Dispersion Spectroscopy ◽  
X Ray ◽  
Silica Source ◽  
Batch System ◽  
Adsorption Capacities ◽  
Gel Technique ◽  
Silica Hybrid

Modification of silica gel with 3-aminopropyltrimethoxysilane and 3-mercaptopropyltrimethoxysilane through sol-gel technique producing amino-silica hybrid (HAS) and mercapto-silica hybrid (HMS), respectively, has been carried out using tetraethylorthosilicate (TEOS) as silica source. The adsorbents were characterized using infrared spectroscopy (IR), and X-ray energy dispersion spectroscopy (EDX). Adsorption of Cd(II) individually as well as its binary mixture with Ni(II), Cu(II), and Zn(II) in solution was performed in a batch system. Adsorption capacities of Cd(II) ion on adsorbent of silica gel (SG), HAS, and HMS are 86.7, 256.4 and 319.5 μmol/g with the adsorption energies are 24.60, 22.61 and 23.15 kJ/mol, respectively. Selectivity coefficient (α) of Cd(II) ion toward combination of Cd(II)/Ni(II), Cd(II)/Cu(II), and Cd(II)/Zn(II) ions on HAS adsorbent is relatively smaller than those on HMS adsorbent which has α > 1.   Keywords: adsorption, amino-silica hybrid, mercapto-silica

Adsorption of gold(III) on ionic imprinted amino-silica hybrid prepared from rice hull ash

2012 ◽  
Vol 85 (1) ◽  
pp. 211-223 ◽  
Author(s):  
Satya Candra Wibawa Sakti ◽  
Dwi Siswanta ◽  
Keyword(s):  
Aqueous Solution ◽  
Contact Time ◽  
Sol Gel ◽  
Ion Concentration ◽  
Rice Hull ◽  
Rice Hull Ash ◽  
Batch System ◽  
Pseudo Second Order ◽  
Gel Technique ◽  
Silica Hybrid

In this research, the adsorption of Au(III) ion on ionic imprinted amino-silica hybrid (Im-ASH) in aqueous solution has been studied. Im-ASH was synthesized via sol-gel technique using a solution of sodium silicate (Na2SiO3) from rice hull ash (RHA) as the precursor and Au(III) ion as the template. Adsorption was carried out in a batch system with variation of pH, contact time, and Au(III) ion concentration. The selectivity of adsorbent toward Au(III) was examined in the presence of Cu(II) ion. The result of the kinetic study demonstrated that the adsorption of Au(III) ion followed pseudo-second order. The optimum adsorption of Au(III) on Im-ASH and non-Im-ASH was obtained at pH of 3.0. Im-ASH was twice as selective toward Au(III) ion than ASH was.

Preparation and Characterization of Nano-Calcium Titanate-Based Coated Silica Gel G and the Application in Adsorption of Heavy Metals

2010 ◽  
Vol 26-28 ◽  
pp. 835-838 ◽  
Author(s):  
Dong Zhang ◽  
Zhi Jiang Liu
Keyword(s):  
Heavy Metals ◽  
Silica Gel ◽  
Sol Gel ◽  
Calcium Titanate ◽  
X Ray Diffraction ◽  
Composite Adsorbent ◽  
Nickel Ions ◽  
X Ray ◽  
Adsorption Capacities

Nano-calcium titanate-based coated silica gel G (GCTO) was prepared by the citric acid sol–gel method and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared spectrophotometry (FTIR). Its lead, cadmium and nickel ions adsorption properties from water were studied. Adsorption and elution were investigated under different conditions. The results showed that the nanometer calcium titanate was immobilized on the silica gel G firmly, becoming a new composite adsorbent. The lead, cadmium and nickel ions were quantitatively retained at pH 5-9; their adsorption capacities of GCTO were 114 mg•g－1, 11.2 mg•g－1 and 20.1 mg•g－1, respectively. The adsorbent can be regenerated completely by elution with 1 mol•L－1 HNO3. The adsorbent has a promising prospect in removal or enriching and separation of heavy metals in water.

scholarly journals Calcination Effect on Structural Trasformation of Barium Titanite Ferroelectric Ceramic by Sol-Gel Method

2019 ◽  
Vol 9 (1) ◽  
pp. 5893-5896
Keyword(s):  
Glacial Acetic Acid ◽  
Sol Gel ◽  
Ferroelectric Ceramic ◽  
Tetrabutyl Titanate ◽  
Chemical Modifier ◽  
Barium Acetate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Gel Technique ◽  
Scanning Electron

High purity barium titanate BaTiO3 was successfully synthesized by using the sol-gel technique. Barium acetate Ba(CH3COO)2 and tetrabutyl titanate, Ti(C4H9O)4 was dissolved moderately in the solvent of glacial acetic acid and ethanol was added as the chemical modifier. The synthesized BaTiO3 nanoparticle was calcined at the temperature range of 700 ºC to 1100 ºC. The powders were further characterized by X-ray diffraction and scanning electron microscopy (SEM). Fined BaTiO3 powders result indicates the phase of tetragonal structures and high crystallites of BaTiO3. It was observed that the crystallinity and particle size of BaTiO3 is greatly influenced by the calcination temperature.

Nanocomposite Dielectric Material: Au/SiO2-gel

1992 ◽  
Vol 286 ◽  
Author(s):  
G.C. Vezzoli ◽  
M.F. Chen
Keyword(s):  
Silica Gel ◽  
Microprobe Analysis ◽  
Dielectric Material ◽  
Sol Gel ◽  
Dielectric Strength ◽  
Optimal Topology ◽  
Gold Chloride ◽  
Gel Technique ◽  
High Dielectric ◽  
Nanocomposite Dielectric

ABSTRACTA nanocomposite of clusters of gold atoms in a silica gel matrix has been prepared by the sol-gel technique through reduction of gold chloride. This composite was fabricated to explore novel techniques for materialsengineering new high dielectric strength substances for capacitor applications. The gold islands amidst the silica gel sea are materials-designed to utilize the percolation threshhold phenomenon to create a peak in the dielectricconstant as a function of optimal topology. Experimental results indicate an average dielectric constant of the order of 5000 at 1 kHz, and a maximum versus temperature at ∼ −100°C. Electron microscope and microprobe analysis indicate ellipsoidal Au particles or clusters of a dimension ranging from a hundred angstroms to several thousand angstroms.

scholarly journals Synthesis Photocatalytic and Antibacterial Activities of Nickle Doped Tio2 Nanoparticles

2018 ◽  
Vol 34 (6) ◽  
pp. 3140-3144
Author(s):  
Ritu Vershney ◽  
Komal Chelaramani ◽  
Arpan Bhardwaj ◽  
Nayma Siddiqui ◽  
Suresh Kumar Verma
Keyword(s):  
Photocatalytic Degradation ◽  
Tio2 Nanoparticles ◽  
Sol Gel ◽  
Antibacterial Activities ◽  
X Ray Diffraction ◽  
Zone Of Inhibition ◽  
Time Duration ◽  
X Ray ◽  
Gel Technique ◽  
Doped Titania

The synthesis of Ni doped titania (TiO2) nanoparticles were achieved via simple novel sol gel technique, in which Titanium-n-butoxide and NiCl2 were taken as precursors. Effect of different wt% of dopant in TiO2 was studied on photocatalytic degradation of Aniline blue and Toluidine Blue. The study suggested the increased photocatalytic degradation with increased time duration. The synthesized samples were analyzed by surface electron microscopy (SEM) and X-ray diffraction studies. The antibacterial activity was investigated against Gram-positive Staphylococcus aureus bacteriae. Studies revealed that on increasing the dopant concentration, the diameter of zone of inhibition also increased upto 1.5 wt%.

Synthesis and Characterization of Immobilized Nanometer Calcium Titanate and the Application in Speciation Analysis for Chromium

2010 ◽  
Vol 129-131 ◽  
pp. 724-727
Author(s):  
Dong Zhang
Keyword(s):  
Silica Gel ◽  
Sol Gel ◽  
Speciation Analysis ◽  
Environmental Water ◽  
Complete Separation ◽  
Calcium Titanate ◽  
X Ray Diffraction ◽  
Ph Values ◽  
Adsorption Capacities

Nanometer calcium titanate immobilized on silica gel G (SGCTO) was prepared by the sol–gel method and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared spectrophotometry (FTIR). Its application in speciation of Cr(III) and Cr(VI) from water was studied. Adsorption and elution were investigated under different conditions. The results showed that the nanometer calcium titanate was immobilized on the silica gel G firmly, becoming a new adsorbent. At normal temperature, two forms of chromium show different adsorption capacities at different pH values, that is, Cr (III) selectively retained at pH 8–14, but Cr(Ⅵ) can’t be adsorbed. Whereas Cr (VI) retained at pH 1, but Cr(Ⅲ) can’t be adsorbed. Hence complete separation of the two forms of chromium is possible. Retained Cr(III) and Cr(VI) were eluted with 1 mol•L−1 HCl and 2 mol•L−1NaOH, respectively. The Cr(III) and Cr(VI) concentration was measured by atomic absorption spectroscopy. The method was successfully applied for the speciation of chromium in environmental water samples.

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.

Polyamide-6,6/in situ silica hybrid nanocomposites by sol–gel technique: synthesis, characterization and properties

Polymer ◽  
2005 ◽  
Vol 46 (10) ◽  
pp. 3343-3354 ◽  
Author(s):  
Rajatendu Sengupta ◽  
Abhijit Bandyopadhyay ◽  
Sunil Sabharwal ◽  
Tapan K. Chaki ◽  
Anil K. Bhowmick
Keyword(s):  
Sol Gel ◽  
Hybrid Nanocomposites ◽  
In Situ Silica ◽  
Gel Technique ◽  
Silica Hybrid

Crystalline Structure and Morphology of the Phases in MgO, TiO2 and ZrO2 Prepared by the Sol-Gel Technique

1995 ◽  
Vol 405 ◽  
Author(s):  
Bokhimi ◽  
J. L. Boldu ◽  
E. Muñoz ◽  
O. Novaro ◽  
T. Lopez ◽  
...  
Keyword(s):  
Crystalline Structure ◽  
Powder Diffraction ◽  
Sol Gel ◽  
Temperature Evolution ◽  
X Ray ◽  
Structure And Morphology ◽  
Gel Technique ◽  
Effect Of Doping

AbstractThe temperature evolution of the crystalline structure of the nanophases found in sol-gel MgO, TiO2 and ZrO2 systems was analyzed by performing x-ray powder diffraction. The structure and concentration of each phase was determined by using the Rietveld technique. The effect of doping MgO and TiO2 systems with platinum was also studied.

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