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Poly (glycidyl methacrylate) - polystyrene diblocks copolymer grafted nanocomposite microspheres from surface - initiated atom transfer radical polymerization for lipase immobilization / Bunyamin Karagoz in Industrial & engineering chemistry research, Vol. 49 N° 20 (Octobre 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 20 (Octobre 2010) . - pp. 9655–9665 Titre : Poly (glycidyl methacrylate) - polystyrene diblocks copolymer grafted nanocomposite microspheres from surface - initiated atom transfer radical polymerization for lipase immobilization : Application in flavor ester synthesis Type de document : texte imprimé Auteurs : Bunyamin Karagoz, Auteur ; Gulay Bayramoglu, Auteur ; Begum Altintas, Auteur Année de publication : 2011 Article en page(s) : pp. 9655–9665 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Copolymer  Nanocomposite  Microspheres Résumé : Functional hairy poly(styrene-b-glycidylmethacrylate) (P(S-GMA)) brushes were generated by grafting from bromoacetylated poly(styrene-divinylbenzene) (P(S-DVB)) microspheres via surface-initiated atom transfer radical polymerization (SI-ATRP). Two different approaches for the covalent immobilization of lipase onto microspheres were studied for the first time: (1) direct immobilization of lipase to the polymer brushes via their epoxy groups, and (2) immobilization of lipase via glutaraldehyde coupling after attachment of a spacer arm (hexamethylendiamine (HMDA)) to the polymer brushes. The covalent immobilization of the lipase on microspheres after spacer-arm attachment and glutaraldeyhde coupling was found to be the more effective than the direct binding method. In this case, a maximum value of the immobilized enzyme activity 498.5 U g−1 was found with an enzyme loading of 27.6 mg per gram of support. Thermal and storage stabilities increase upon immobilization on the P(S-DVB)-g-P(S-GMA)-HMDA-GA microspheres. Finally, esterification reactions have been performed to produce ethyl acetate and isoamyl acetate in a solvent-free system and in n-hexane using lipase-immobilized P(S-DVB)-g-P(S-GMA)-HMDA-GA microspheres. The immobilized lipase was effectively reused in successive batch runs in a solvent-free system for isoamyl acetate synthesis, and only 21% activity was lost after 10 cycles. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie101351u [article] Poly (glycidyl methacrylate) - polystyrene diblocks copolymer grafted nanocomposite microspheres from surface - initiated atom transfer radical polymerization for lipase immobilization : Application in flavor ester synthesis [texte imprimé] / Bunyamin Karagoz, Auteur ; Gulay Bayramoglu, Auteur ; Begum Altintas, Auteur . - 2011 . - pp. 9655–9665. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 20 (Octobre 2010) . - pp. 9655–9665 Mots-clés : Copolymer  Nanocomposite  Microspheres Résumé : Functional hairy poly(styrene-b-glycidylmethacrylate) (P(S-GMA)) brushes were generated by grafting from bromoacetylated poly(styrene-divinylbenzene) (P(S-DVB)) microspheres via surface-initiated atom transfer radical polymerization (SI-ATRP). Two different approaches for the covalent immobilization of lipase onto microspheres were studied for the first time: (1) direct immobilization of lipase to the polymer brushes via their epoxy groups, and (2) immobilization of lipase via glutaraldehyde coupling after attachment of a spacer arm (hexamethylendiamine (HMDA)) to the polymer brushes. The covalent immobilization of the lipase on microspheres after spacer-arm attachment and glutaraldeyhde coupling was found to be the more effective than the direct binding method. In this case, a maximum value of the immobilized enzyme activity 498.5 U g−1 was found with an enzyme loading of 27.6 mg per gram of support. Thermal and storage stabilities increase upon immobilization on the P(S-DVB)-g-P(S-GMA)-HMDA-GA microspheres. Finally, esterification reactions have been performed to produce ethyl acetate and isoamyl acetate in a solvent-free system and in n-hexane using lipase-immobilized P(S-DVB)-g-P(S-GMA)-HMDA-GA microspheres. The immobilized lipase was effectively reused in successive batch runs in a solvent-free system for isoamyl acetate synthesis, and only 21% activity was lost after 10 cycles. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie101351u