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Adsorption of Cu2+ on amino functionalized silica gel with different loading / Manu V. in Industrial & engineering chemistry research, Vol. 48 N° 19 (Octobre 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 19 (Octobre 2009) . - pp. 8954–8960 Titre : Adsorption of Cu2+ on amino functionalized silica gel with different loading Type de document : texte imprimé Auteurs : Manu V., Auteur ; Haresh M. Mody, Auteur ; Hari C. Bajaj, Auteur Année de publication : 2009 Article en page(s) : pp. 8954–8960 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Silica  gel  Amino  functionalized  silica  gel  Cu2+  Adsorption Résumé : Silica gel (G) and amino functionalized silica gel with three different loading of an aminopropyl group viz. 0.51, 1.01, and 1.45 mmol/g, (GN1, GN2, and GN3) were synthesized, characterized, and used as adsorbents for the adsorption of Cu2+ ions from aqueous solution. The specific surface area, pore volume, and BJH pore size of silica gel decreased with an increase in the loading of aminopropyl groups. Kinetic of adsorption of Cu2+ on GN2 followed pseudosecond order. Adsorption isotherms of Cu2+ on functionalized silica samples were best fit by the Sips model for all the three functionalized silica gels, among the four models used to describe the Cu2+ adsorption isotherms. The monolayer copper adsorption capacity for the gel GN1 (0.515 mmol Cu2+/g) and GN2 (0.55 mmol Cu2+/g) were found to be almost similar even when the loading of the amino group increased from 0.51 to 1.01 mmol/g. The NH2/Cu mole ratio was found to be around 1 and 2 for GN1 and GN2, respectively. In the case of GN3 (1.45 mmol NH2/g), the monolayer capacity was found to be 1.05 mmol Cu2+/g with a NH2/Cu mole ratio of 1.38. This study indicates that the population density of NH2 determines the NH2/Cu2+ ratio at saturation of Cu2+ on the functionalized silica gel and the affinity of the gel for the Cu2+. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900273v [article] Adsorption of Cu2+ on amino functionalized silica gel with different loading [texte imprimé] / Manu V., Auteur ; Haresh M. Mody, Auteur ; Hari C. Bajaj, Auteur . - 2009 . - pp. 8954–8960. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 19 (Octobre 2009) . - pp. 8954–8960 Mots-clés : Silica  gel  Amino  functionalized  silica  gel  Cu2+  Adsorption Résumé : Silica gel (G) and amino functionalized silica gel with three different loading of an aminopropyl group viz. 0.51, 1.01, and 1.45 mmol/g, (GN1, GN2, and GN3) were synthesized, characterized, and used as adsorbents for the adsorption of Cu2+ ions from aqueous solution. The specific surface area, pore volume, and BJH pore size of silica gel decreased with an increase in the loading of aminopropyl groups. Kinetic of adsorption of Cu2+ on GN2 followed pseudosecond order. Adsorption isotherms of Cu2+ on functionalized silica samples were best fit by the Sips model for all the three functionalized silica gels, among the four models used to describe the Cu2+ adsorption isotherms. The monolayer copper adsorption capacity for the gel GN1 (0.515 mmol Cu2+/g) and GN2 (0.55 mmol Cu2+/g) were found to be almost similar even when the loading of the amino group increased from 0.51 to 1.01 mmol/g. The NH2/Cu mole ratio was found to be around 1 and 2 for GN1 and GN2, respectively. In the case of GN3 (1.45 mmol NH2/g), the monolayer capacity was found to be 1.05 mmol Cu2+/g with a NH2/Cu mole ratio of 1.38. This study indicates that the population density of NH2 determines the NH2/Cu2+ ratio at saturation of Cu2+ on the functionalized silica gel and the affinity of the gel for the Cu2+. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900273v

Effect of thermal treatment of silica gels on their amino functionalization and subsequent adsorption properties for Cu2+ from aqueous solution of copper sulfate / Manu V. in Industrial & engineering chemistry research, Vol. 49 N° 17 (Septembre 1, 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 17 (Septembre 1, 2010) . - pp 8184–8191 Titre : Effect of thermal treatment of silica gels on their amino functionalization and subsequent adsorption properties for Cu2+ from aqueous solution of copper sulfate Type de document : texte imprimé Auteurs : Manu V., Auteur ; Haresh M. Mody, Auteur ; Hari C. Bajaj, Auteur Année de publication : 2010 Article en page(s) : pp 8184–8191 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Thermal  treatment  Aqueous  solution. Résumé : Hydrothermally prepared mesoporous silica gel (prepared under acidic condition) was calcined at different temperatures to control concentration of surface hydroxyl groups. These materials were functionalized with 3-aminopropyltrimethoxysilane (APTMS) and used for the adsorption of Cu2+ ions. Adsorption isotherm and adsorption capacity of the amine functionalized materials for Cu2+ were followed by inductively coupled plasma optical emission spectrometry (ICP-OES). The adsorption capacity for functionalized silica gel was correlated with population density of hydroxyl groups and hence amine content in the materials, which was determined by CHN analysis. Nitrogen adsorption/desorption measurements at liquid N2 temperature, Fourier transform infrared spectrometry (FTIR), and 29Si MAS NMR spectra were used to follow the changes in the textural parameters and surface properties of the mesoporous silica gel samples. This study indicates that thermal treatment of silica gel determines the population density of surface hydroxyl groups and hence the NH2 population density after functionalization of the gels, which in turn determines the NH2/Cu2+ ratio at saturation of Cu2+ on the functionalized silica gel. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1007773 [article] Effect of thermal treatment of silica gels on their amino functionalization and subsequent adsorption properties for Cu2+ from aqueous solution of copper sulfate [texte imprimé] / Manu V., Auteur ; Haresh M. Mody, Auteur ; Hari C. Bajaj, Auteur . - 2010 . - pp 8184–8191. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 17 (Septembre 1, 2010) . - pp 8184–8191 Mots-clés : Thermal  treatment  Aqueous  solution. Résumé : Hydrothermally prepared mesoporous silica gel (prepared under acidic condition) was calcined at different temperatures to control concentration of surface hydroxyl groups. These materials were functionalized with 3-aminopropyltrimethoxysilane (APTMS) and used for the adsorption of Cu2+ ions. Adsorption isotherm and adsorption capacity of the amine functionalized materials for Cu2+ were followed by inductively coupled plasma optical emission spectrometry (ICP-OES). The adsorption capacity for functionalized silica gel was correlated with population density of hydroxyl groups and hence amine content in the materials, which was determined by CHN analysis. Nitrogen adsorption/desorption measurements at liquid N2 temperature, Fourier transform infrared spectrometry (FTIR), and 29Si MAS NMR spectra were used to follow the changes in the textural parameters and surface properties of the mesoporous silica gel samples. This study indicates that thermal treatment of silica gel determines the population density of surface hydroxyl groups and hence the NH2 population density after functionalization of the gels, which in turn determines the NH2/Cu2+ ratio at saturation of Cu2+ on the functionalized silica gel. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1007773

Energy efficient UV-LED source and TiO2nNanotube array-based reactor for photocatalytic application / Thillai Sivakumar Natarajan in Industrial & engineering chemistry research, Vol. 50 N° 13 (Juillet 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 13 (Juillet 2011) . - pp. 7753-7762 Titre : Energy efficient UV-LED source and TiO2nNanotube array-based reactor for photocatalytic application Type de document : texte imprimé Auteurs : Thillai Sivakumar Natarajan, Auteur ; Kalithasan Natarajan, Auteur ; Hari C. Bajaj, Auteur Année de publication : 2011 Article en page(s) : pp. 7753-7762 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Photocatalysis  Reactor  Titanium  oxide  Ultraviolet  radiation Résumé : The present study focuses on the development and feasibility of ultraviolet light emitting diode (UV-LED) source and TiO2 nanotube array (TNA)-based photocatalytic reactor for Congo red (CR) dye degradation. Highly ordered TNA was synthesized by the anodization method. The synthesized highly ordered TNA was characterized by X- ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscope (AFM), and electronic impedance spectroscopy (EIS) techniques. The percentage degradation was determined using a UV-visible spectrophotometer, while the mineralization of CR dye was further confirmed by chemical oxygen demand (COD) and kinetic analysis. The effect of operational parameters such as initial concentration of dye and pH on the degradation of CR dye has been studied to determine the optimum conditions. A possible degradation mechanism based on the electrospray ionization mass spectrometry (ESI-MS) has been suggested. The results demonstrated that CR dye was completely degraded in 5 h using the designed photocatalytic reactor. The electrical energy per order (EEo) was calculated for estimating the electrical energy efficiency. The result demonstrated that highly adhered nanotube array can effectively be used for photocatalytic degradation of CR dye in the presence of UV-LED light irradiation. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24332097 [article] Energy efficient UV-LED source and TiO2nNanotube array-based reactor for photocatalytic application [texte imprimé] / Thillai Sivakumar Natarajan, Auteur ; Kalithasan Natarajan, Auteur ; Hari C. Bajaj, Auteur . - 2011 . - pp. 7753-7762. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 13 (Juillet 2011) . - pp. 7753-7762 Mots-clés : Photocatalysis  Reactor  Titanium  oxide  Ultraviolet  radiation Résumé : The present study focuses on the development and feasibility of ultraviolet light emitting diode (UV-LED) source and TiO2 nanotube array (TNA)-based photocatalytic reactor for Congo red (CR) dye degradation. Highly ordered TNA was synthesized by the anodization method. The synthesized highly ordered TNA was characterized by X- ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscope (AFM), and electronic impedance spectroscopy (EIS) techniques. The percentage degradation was determined using a UV-visible spectrophotometer, while the mineralization of CR dye was further confirmed by chemical oxygen demand (COD) and kinetic analysis. The effect of operational parameters such as initial concentration of dye and pH on the degradation of CR dye has been studied to determine the optimum conditions. A possible degradation mechanism based on the electrospray ionization mass spectrometry (ESI-MS) has been suggested. The results demonstrated that CR dye was completely degraded in 5 h using the designed photocatalytic reactor. The electrical energy per order (EEo) was calculated for estimating the electrical energy efficiency. The result demonstrated that highly adhered nanotube array can effectively be used for photocatalytic degradation of CR dye in the presence of UV-LED light irradiation. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24332097

Photocatalytic degradation of methylene blue dye using ultraviolet light emitting diodes / Rajesh J. Tayade in Industrial & engineering chemistry research, Vol. 48 N° 23 (Décembre 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10262–10267 Titre : Photocatalytic degradation of methylene blue dye using ultraviolet light emitting diodes Type de document : texte imprimé Auteurs : Rajesh J. Tayade, Auteur ; Thillai Sivakumar Natarajan, Auteur ; Hari C. Bajaj, Auteur Année de publication : 2010 Article en page(s) : pp. 10262–10267 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Photocatalytic--Degradation--Methylene--Blue  Dye--Using--Ultraviolet--Emitting  Diodes Résumé : This study was focused on the application of ultraviolet light emitting diodes (UV-LED) as an alternate source for the photocatalytic degradation of methylene blue (MB), which was used as a model compound. A simple reactor arrangement was made to carry out the photocatalytic degradation of methylene blue dye. The photocatalytic activity of P-25 Degussa TiO2 was evaluated using UV-LED reactor. The decomposition of MB dye in aqueous solution by TiO2 photocatalytic process with the UV-LED was found to be technically feasible. The effects of various parameters such as catalyst loading, initial dye concentration, pH, and addition of H2O2 on decolorization and degradation have been investigated to find the optimum conditions. The complete mineralization of MB dye (3.12 × 10−5 M) was confirmed by chemical oxygen demand analysis. Results demonstrated that the UV-LED/TiO2 process can effectively degrade methylene blue dye with optimum conditions. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9012437 [article] Photocatalytic degradation of methylene blue dye using ultraviolet light emitting diodes [texte imprimé] / Rajesh J. Tayade, Auteur ; Thillai Sivakumar Natarajan, Auteur ; Hari C. Bajaj, Auteur . - 2010 . - pp. 10262–10267. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10262–10267 Mots-clés : Photocatalytic--Degradation--Methylene--Blue  Dye--Using--Ultraviolet--Emitting  Diodes Résumé : This study was focused on the application of ultraviolet light emitting diodes (UV-LED) as an alternate source for the photocatalytic degradation of methylene blue (MB), which was used as a model compound. A simple reactor arrangement was made to carry out the photocatalytic degradation of methylene blue dye. The photocatalytic activity of P-25 Degussa TiO2 was evaluated using UV-LED reactor. The decomposition of MB dye in aqueous solution by TiO2 photocatalytic process with the UV-LED was found to be technically feasible. The effects of various parameters such as catalyst loading, initial dye concentration, pH, and addition of H2O2 on decolorization and degradation have been investigated to find the optimum conditions. The complete mineralization of MB dye (3.12 × 10−5 M) was confirmed by chemical oxygen demand analysis. Results demonstrated that the UV-LED/TiO2 process can effectively degrade methylene blue dye with optimum conditions. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9012437

Synthesis of organoclays with controlled particle size and whiteness from chemically treated indian bentonite / Patel, Hasmukh A. in Industrial & engineering chemistry research, Vol. 49 N° 4 (Fevrier 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1677–1683 Titre : Synthesis of organoclays with controlled particle size and whiteness from chemically treated indian bentonite Type de document : texte imprimé Auteurs : Patel, Hasmukh A., Auteur ; Somani, Rajesh S., Auteur ; Hari C. Bajaj, Auteur Année de publication : 2010 Article en page(s) : pp 1677–1683 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Organoclays  nanoclays  Chemically  treated  bentonites. Résumé : Organoclays or nanoclays have gained increased attention from industry as well as academia during the past 11/2 decades. These clays are prepared from natural clays which invariably have other minerals as impurities. It is of prime significance to remove impurities from organoclays which find applications in polymer nanocomposites, paints, cosmetics, and medicinal formulations. The Indian bentonites were treated with sulfuric acid, hydrochloric acid, hydrogen peroxide, oxalic acid, citric acid, and sodium dithionite to remove impurities invariably present in natural clays. Treatment with both minerals and organic acid could remove both interlayer and structural iron and improve the whiteness with breaking up layered structure. However, sodium dithionite treatment is observed to be more suited to remove iron impurities from bentonite and improve whiteness to 11% without any effect on the structure of the clay. Chemically treated bentonites were used for preparing organoclays in a single step to eliminate the filtration and washing steps. The organoclays were prepared under varied reaction parameters such as temperature, the amount and type of organic modifier, and the concentration of the clay. The optimization of these parameters was done to prepare orgnaoclays with controlled particle size and whiteness. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801368b [article] Synthesis of organoclays with controlled particle size and whiteness from chemically treated indian bentonite [texte imprimé] / Patel, Hasmukh A., Auteur ; Somani, Rajesh S., Auteur ; Hari C. Bajaj, Auteur . - 2010 . - pp 1677–1683. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1677–1683 Mots-clés : Organoclays  nanoclays  Chemically  treated  bentonites. Résumé : Organoclays or nanoclays have gained increased attention from industry as well as academia during the past 11/2 decades. These clays are prepared from natural clays which invariably have other minerals as impurities. It is of prime significance to remove impurities from organoclays which find applications in polymer nanocomposites, paints, cosmetics, and medicinal formulations. The Indian bentonites were treated with sulfuric acid, hydrochloric acid, hydrogen peroxide, oxalic acid, citric acid, and sodium dithionite to remove impurities invariably present in natural clays. Treatment with both minerals and organic acid could remove both interlayer and structural iron and improve the whiteness with breaking up layered structure. However, sodium dithionite treatment is observed to be more suited to remove iron impurities from bentonite and improve whiteness to 11% without any effect on the structure of the clay. Chemically treated bentonites were used for preparing organoclays in a single step to eliminate the filtration and washing steps. The organoclays were prepared under varied reaction parameters such as temperature, the amount and type of organic modifier, and the concentration of the clay. The optimization of these parameters was done to prepare orgnaoclays with controlled particle size and whiteness. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801368b