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Effects of magnesium and zirconium dopants on characteristics of titanium(IV) oxide fibers prepared by combined sol–gel and electrospinning techniques / Jerawut Kaewsaenee 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. 8042-8049 Titre : Effects of magnesium and zirconium dopants on characteristics of titanium(IV) oxide fibers prepared by combined sol–gel and electrospinning techniques Type de document : texte imprimé Auteurs : Jerawut Kaewsaenee, Auteur ; Pinpan Visal-athaphand, Auteur ; Pitt Supaphol, Auteur Année de publication : 2011 Article en page(s) : pp. 8042-8049 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Oxide  fibers  Electrospinning  Techniques Résumé : The sol–gel and electrospinning techniques were combined to produce poly(vinylpyrrolidone) (PVP)/titanium(IV) oxide composite fibers from solutions containing PVP and titanium tetraisopropoxide. Either magnesium nitrate hexahydrate or zirconyl(IV) nitrate hydrate was added to the solutions as a source of magnesium or zirconium dopant, respectively. Upon calcination of the as-spun fibers, metal-doped titania fibers were obtained. The presence of either magnesium or zirconium dopant affected both the physical and chemical properties of the as-synthesized titania fibers and even retarded the formation of the rutile phase. Various characterization techniques were employed to confirm the increased content of Ti3+ defects and oxygen vacancies within the titania structures resulting from the presence of the metal dopants. These defects were found to trap photoexcited charges (i.e., electrons and holes), thus retarding the recombination of electron–hole pairs. This led to an enhancement of the photocatalytic activity of the titania structures. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie102527p [article] Effects of magnesium and zirconium dopants on characteristics of titanium(IV) oxide fibers prepared by combined sol–gel and electrospinning techniques [texte imprimé] / Jerawut Kaewsaenee, Auteur ; Pinpan Visal-athaphand, Auteur ; Pitt Supaphol, Auteur . - 2011 . - pp. 8042-8049. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 13 (Juillet 2011) . - pp. 8042-8049 Mots-clés : Oxide  fibers  Electrospinning  Techniques Résumé : The sol–gel and electrospinning techniques were combined to produce poly(vinylpyrrolidone) (PVP)/titanium(IV) oxide composite fibers from solutions containing PVP and titanium tetraisopropoxide. Either magnesium nitrate hexahydrate or zirconyl(IV) nitrate hydrate was added to the solutions as a source of magnesium or zirconium dopant, respectively. Upon calcination of the as-spun fibers, metal-doped titania fibers were obtained. The presence of either magnesium or zirconium dopant affected both the physical and chemical properties of the as-synthesized titania fibers and even retarded the formation of the rutile phase. Various characterization techniques were employed to confirm the increased content of Ti3+ defects and oxygen vacancies within the titania structures resulting from the presence of the metal dopants. These defects were found to trap photoexcited charges (i.e., electrons and holes), thus retarding the recombination of electron–hole pairs. This led to an enhancement of the photocatalytic activity of the titania structures. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie102527p

Preparation of hydrolyzed electrospun polyacrylonitrile fiber mats as chelating substrates / Pimolpun Kampalanonwat in Industrial & engineering chemistry research, Vol. 50 N° 21 (Novembre 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 11912-11921 Titre : Preparation of hydrolyzed electrospun polyacrylonitrile fiber mats as chelating substrates : a case study on copper(II) ions Type de document : texte imprimé Auteurs : Pimolpun Kampalanonwat, Auteur ; Pitt Supaphol, Auteur Année de publication : 2011 Article en page(s) : pp. 11912-11921 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Hydrolyzed  Electrospun  Copper  Ions Résumé : Ultrafine polyacrylonitrile (PAN) fiber mats were prepared by electrospinning and subsequently hydrolytically treated with a sodium hydroxide ethanolic/aqueous solution to impart the ability to chelate metal ions. This was achieved through the conversion of the nitrile functional groups on the surface of the PAN fibers into imine conjugated sequences, which was confirmed by Fourier-transform infrared spectroscopy. The chelating property of the hydrolyzed electrospun PAN fiber mats (i.e., H-ePAN fiber mats) was evaluated against Cu(U) ions. The amounts ofthe Cu(II) ions adsorbed onto the H-ePAN fiber mats were influenced by the initial pH and the initial concentration of the metal ion solutions. At the optimal pH of 5.0, the amounts of the Cu(II) ions adsorbed onto the H-ePAN fiber mats increased with an initial increase in the time the materials were in contact with the metal ion solution to finally reach the maximal, plateau values after about 5 h of immersion. The maximal adsorption capacity of the H-ePAN fiber mats for the Cu(II) ions was determined to be 31.3 mg g-1, and the fully adsorbed materials could be regenerated upon submersion in 0.1 M hydrochloric acid aqueous solution for 30 min. Finally, X-ray photoelectron spectroscopy indicated specific interactions between the adsorbed Cu(II) ions and the N- and/or the O-atoms associated with the imine groups on the. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie200504c [article] Preparation of hydrolyzed electrospun polyacrylonitrile fiber mats as chelating substrates : a case study on copper(II) ions [texte imprimé] / Pimolpun Kampalanonwat, Auteur ; Pitt Supaphol, Auteur . - 2011 . - pp. 11912-11921. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 11912-11921 Mots-clés : Hydrolyzed  Electrospun  Copper  Ions Résumé : Ultrafine polyacrylonitrile (PAN) fiber mats were prepared by electrospinning and subsequently hydrolytically treated with a sodium hydroxide ethanolic/aqueous solution to impart the ability to chelate metal ions. This was achieved through the conversion of the nitrile functional groups on the surface of the PAN fibers into imine conjugated sequences, which was confirmed by Fourier-transform infrared spectroscopy. The chelating property of the hydrolyzed electrospun PAN fiber mats (i.e., H-ePAN fiber mats) was evaluated against Cu(U) ions. The amounts ofthe Cu(II) ions adsorbed onto the H-ePAN fiber mats were influenced by the initial pH and the initial concentration of the metal ion solutions. At the optimal pH of 5.0, the amounts of the Cu(II) ions adsorbed onto the H-ePAN fiber mats increased with an initial increase in the time the materials were in contact with the metal ion solution to finally reach the maximal, plateau values after about 5 h of immersion. The maximal adsorption capacity of the H-ePAN fiber mats for the Cu(II) ions was determined to be 31.3 mg g-1, and the fully adsorbed materials could be regenerated upon submersion in 0.1 M hydrochloric acid aqueous solution for 30 min. Finally, X-ray photoelectron spectroscopy indicated specific interactions between the adsorbed Cu(II) ions and the N- and/or the O-atoms associated with the imine groups on the. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie200504c