scholarly journals L-Arginine-Modified Silica for Adsorption of Gold(III)

2015 ◽  
Vol 15 (2) ◽  
pp. 108-115 ◽  
Author(s):  
Sri Hastuti ◽  
Nuryono Nuryono ◽  
Agus Kuncaka

In this research, L-arginine-modified silica (SiO2-Arg) with 3-glycidoxypropyl-trimethoxysilane (GPTMS) as the linking agent has been synthesized through sol gel process for adsorption of Au(III) in aqueous solution. Tetraethyl orthosilicate (TEOS) as the silica source precursor, L-arginine solution 0.9 M with various volume ratios and the linking agent were mixed together to form a gel. SiO2-Arg was characterized using Fourier transform infrared (FTIR) spectrophotometer, thermogravimetric analysis (TGA), and an elemental analysis. Adsorption was carried out in a batch system under various experimental conditions including contact time and initial concentration of metal Au(III). The selectivity of adsorbent toward Au(III) was examined in the presence of Cu(II), Fe(III), and Zn(II) ion at various pHs. Results of characterization showed that silica has been successfully modified with L-arginine. The optimum adsorption of Au(III) on SiO2-Arg was obtained at pH of 3.0 and the adsorption isotherm of Au(III) on SiO2-Arg gives the adsorption capacity of 52.79 mg/g. The kinetic study demonstrates that the adsorption of Au(III) ion follows pseudo-second order with the rate constant of 53197 g mol–1 min–1. The selectivity order of Au-Zn = Au-Cu > Au-Fe. This sol-gel preparation is simple and provides prospective application of SiO2-Arg material as an effective adsorbent for metal ions particularly gold(III).

2019 ◽  
Vol 19 (2) ◽  
pp. 395
Author(s):  
Nuryono Nuryono ◽  
Nur Mutia Rosiati ◽  
Abraham L Rettob ◽  
Suyanta Suyanta ◽  
Yateman Arryanto

Two novel materials of 2-aminobenzimidiazole (AB) and 1-(o-tolyl)biguanide (TB) modified silicas coated on the iron sand magnetic material (MM@SiO2/AB and MM@SiO2/TB) have been synthesized and were used to adsorb Au(III) from Au/Cu/Ni solution. Silica layering MM was modified with polyamino compounds via a sol-gel process using a sodium silicate solution, 3-chloropropyltrimethoxysilane (CPTS) and modifier compounds. Adsorption of Au(III) on MM@SiO2/AB and MM@SiO2/TB was investigated in a batch system by varying pH, initial concentration, contact time and the presence of other metal ions (Cu(II) and Ni(II)). The results showed that MM@SiO2/AB and MM@SiO2/TB were successfully synthesized through the sol-gel process using cross-linking agent CPTS. Adsorption of Au(III) on MM@SiO2/AB and MM@SiO2/TB decreased with the increase of pH and followed the Langmuir isotherm models with adsorption capacity of 17.15 and 9.44 mg/g, respectively. The adsorption kinetics fit to pseudo-second-order model with the rate constants of 1.16 × 10-2 and 1.46 × 10-2 g mg-1 min-1, respectively. MM@SiO2/AB and MM@SiO2/TB gave a high selectivity towards Au(III) in a mixture of Cu(II) and Ni(II). The desorption using thiourea 1 M solution in 1 M HCl of metal ions showed that percentage of Au(III) desorbed was higher than that of Cu(II) and Ni(II).


2019 ◽  
Vol 19 (2) ◽  
pp. 337 ◽  
Author(s):  
Ngatijo Ngatijo ◽  
Rahmat Basuki ◽  
Nuryono Nuryono ◽  
Bambang Rusdiarso

Amine-Modified Silica (AMS) and Quaternary Amine-Modified Silica (QAMS) has been synthesized through the sol-gel process for adsorption Au(III) in aqueous solution. The aim of this work was to compare the effect of addition three methyl group of AMS to form QAMS on its character, thermodynamics and kinetics parameter of sorption of Au(III) in aqueous solution. Characterizations performed by FT-IR, XRD, SEM and BET analyzer. Sorption study was carried out in a batch system under the various experimental conditions including the effect of medium acidity, a variation of Au(III) concentration (thermodynamics study), and variation of contact time (kinetics study). Optimum pH of sorption Au(III) on AMS was 3 and shift into 5 on QAMS. Thermodynamics sorption study by Langmuir isotherm models indicates that there was an increase of sorption capacity from 37.94 mg/g (AMS) to 74.47 mg/g (QAMS). Kinetics sorption studies by Lagergren, Ho, and RBS models indicate that the sorption Au(III) in this research fitted well with the RBS models. The addition of 3 methyl group also increased the sorption rate of Au(III) on QAMS (ka = 77.29 min-1 (mole/L)-1) over AMS (ka = 69.22 min-1 (mole/L)-1) and reinforce the electrostatic interaction between active site of QAMS.


2015 ◽  
Vol 47 (1) ◽  
pp. 1-12 ◽  
Author(s):  
M. Mazúr ◽  
L. Husáriková ◽  
M. Valko ◽  
C. J. Rhodes

2010 ◽  
Vol 113-116 ◽  
pp. 2266-2270
Author(s):  
Jing Li ◽  
Wei Xue ◽  
Yong Zhao ◽  
Zhi Miao Wang

A novel method of microemulsion coupling with sol–gel process was used for preparation of porous silica using tetraethyl orthosilicate as silicon source. Effect of solvent and catalyst on the surface texture properties was investigated respectively. The results showed that porous silica with large specific surface area (738.65 m2/g) and high pore volume (2.01 cm3/g) was obtained. However, the mesopores in silica were arranged in disorder and showed great ununiformity in shape and arrangement. To obtain porous silica with desired texture properties, an appropriate dosage of ethanol and higher HCl concentration were needed.


2019 ◽  
Vol 8 (1) ◽  
pp. 39 ◽  
Author(s):  
Susanto Susanto ◽  
Ricka Prasdiantika

Synthesis of Fe3O4@SiO2 modified with propyldiethylenetriamine (Fe3O4@SiO2@PDETA) with variation of synthesis routes have been investigated. Research was begun with synthesis of Fe3O4 using dispersion agent of trisodium citrate at coprecipitation system through stirring using ultrasonic wave. Coating magnetite with propyldiethylenetriamine modified silica was carried out through sol-gel process with two different mixing sequences of raw materials (two synthesis routes) with main materials of Fe3O4 synthesized, N-[3-(Trimethoxysilyl)propyl]-diethylenetriamine (TMSPDETA) and Na2SiO3. The products were characterized by fourier transform infrared (FTIR) spectrophotometer and scanning electron microscope-energy dispersive X-ray (SEM-EDX). Results indicate that Fe3O4@SiO2@PDETA has been synthesized succesfully. Fe3O4@SiO2@PDETA synthesized through route 1 (magnetite mixed with a mixture TMSPDETA and Na2SiO3) contains more propyldiethylenetriamine group than that of through route 2 (magnetite mixed with Na2SiO3 solution, then mixed with TMSPDETA)


2019 ◽  
Vol 280 ◽  
pp. 03010 ◽  
Author(s):  
Dwi Rasy Mujiyanti ◽  
Muthia Elma ◽  
Mufidah Amalia

Interlayer-free glucose carbonized template silica membranesbased on tetraethyl orthosilicate (TEOS) and glucose were successfullyprepared using an acid-base catalysed sol-gel method for artificial brinewater desalination (7.5% wt NaCl solution %) at temperatures range from25, 40 and 60 °C. These membranes calcined at 250 and 400 °C. Themembranes were fabricated through sol-gel process by using TEOS(tetraethyl orthosilicate); ethanol; nitric acid; ammonia; aquadest andglucose as a template. By molar ratio is 1: 38: 0.0007: 0.0003: 5 and0.25%; 0.5%, 1% w/v glucose as template. The results show the highestwater fluxes of 1.8, 2.2 and 4.8 kg m−2 h−1 for 25, 40 and 60 °Cdesalination process with excellent salt rejections of 99.5, 99.5 and 99.7%, respectively. It was found that the higher the NaCl solution temperature asfeed solution as well as glucose concentration (0.25% to 1% wt) astemplate attached in the silica matrixes, the higher water fluxes eventhough the salt rejection remain the same. This study demonstrates that theorganosilica membranes offered the carbonized silica mesostructuremembranes with excellent separation of water from the hydrated salt ions, particularly for processing brine salt solutions.


2012 ◽  
Vol 529-530 ◽  
pp. 637-640
Author(s):  
Jie Li ◽  
Yuki Shirosaki ◽  
Satoshi Hayakawa ◽  
Artemis Stamboulis ◽  
Akiyoshi Osaka

Silica gel macrospheres of 2~4 mm in size, and wrapped with Ca-alginate chelate film were prepared as the substrate for hydroxyapatite coating layer, using water glass as the silica source. Those Ca-SiO2 macrospheres were soaked in a 1:1 (volume) mixture of ethanol and 0.1 M Na2HPO4 to deposit hydroxyapatite layer (HAp-SiO2 macrospheres). Adsorption of bovine serum albumin and egg lysozyme on those Ca-SiO2 and HAp-SiO2 macrospheres under physiological pH (7.2) was well correlated to the Langmuir-type adsorption equation. The electrostatic interactions between the protein molecules and those macrospheres well interpret the adsorption isotherms, while the mesopores in the Ca-SiO2 contributed to some extent. A multi-layer adsorption model was proposed.


2011 ◽  
Vol 399-401 ◽  
pp. 390-393
Author(s):  
Ai Huan Gao ◽  
Pi Hui Pi ◽  
Jiang Cheng ◽  
Zhuo Ru Yang

Aluminum sheet was encapsulated by inorganic-organic hybrid film through a base catalyzed sol-gel method using organic acrylate silane resin PMBV and TEOS as precursors. FTIR and AFM characterizations prove that PMBV and TEOS have hydrolyzed and co-condensed with each other in the sol-gel process to form an uniform film on the surface of aluminum sheet. XPS result shows hydroxyl groups on aluminum surface have taken part in the co-condensation reaction.


2012 ◽  
Vol 535-537 ◽  
pp. 2563-2566 ◽  
Author(s):  
Yu Ma ◽  
Hye Ryeon Lee ◽  
Toshinori Tsuru

The synthesis of hydrophobic sol by one-step sol-gel process ammonia catalyzed was investigated. The water molar ratio and catalyst molar ratio were discussed to prevent phase segregation during the hydrolysis and co-condensation of the organic and inorganic precursors. The reactant system with water molar ratio 70 could make the reaction rate of MTES slightly less than that of TEOS, so that the hydrolysis - condensation – gelling reaction with MTES and TEOS as co-precursors could be synchronously. With the increase of the MTES/TEOS molar ratio, the reaction rate of the silica sol preparation decreased, the hydrophobicity of the sol and gel increased as the molar ratio MTES/TEOS change from 0.5~4. But the hydrophobicity of the methyl-modified silica sol and gel prepared with pure MTES in the sol-gel process were slightly lower than that of the methyl-modified silica sol and gel prepared with MTES and TEOS as co-precursors.


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