Documents disponibles écrits par cet auteur

Wet cross-linking of cellulose fibers via a bioconjugation reaction / Alvaro Tejado in Industrial & engineering chemistry research, Vol. 50 N° 10 (Mai 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 5907-5913 Titre : Wet cross-linking of cellulose fibers via a bioconjugation reaction Type de document : texte imprimé Auteurs : Alvaro Tejado, Auteur ; Miro Antal, Auteur ; Xiaojun Liu, Auteur Année de publication : 2011 Article en page(s) : pp. 5907-5913 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Cellulose  Fiber Résumé : A well-known bioconjugation reaction, the EDC-assisted reaction of carboxyl and amine groups, is shown to be extremely well-adapted for cross-linking fibers under papermaking conditions. By using such chemistry we obtained increases as high as 500% and 100% in the wet-web strength (WWS) of papers made from, respectively, unbeaten and beaten hardwood kraft pulps, after pretreating the fibers with carboxymethyl cellulose and using adipic dihydrazide as the cross-linker. These increments exceed previous attempts in most cases by about 1 order of magnitude. Experiments show that the cross-linking reaction does not counteract the beating effect, as has usually occurred in the past for other cross-linking routes, but instead complements it. The ability ofEDC for promoting covalent bonding under very wet conditions appears to make it an excellent agent for the enhancement of the WWS of paper, the property that ultimately determines the runnability of a papermaking machine. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158886 [article] Wet cross-linking of cellulose fibers via a bioconjugation reaction [texte imprimé] / Alvaro Tejado, Auteur ; Miro Antal, Auteur ; Xiaojun Liu, Auteur . - 2011 . - pp. 5907-5913. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 5907-5913 Mots-clés : Cellulose  Fiber Résumé : A well-known bioconjugation reaction, the EDC-assisted reaction of carboxyl and amine groups, is shown to be extremely well-adapted for cross-linking fibers under papermaking conditions. By using such chemistry we obtained increases as high as 500% and 100% in the wet-web strength (WWS) of papers made from, respectively, unbeaten and beaten hardwood kraft pulps, after pretreating the fibers with carboxymethyl cellulose and using adipic dihydrazide as the cross-linker. These increments exceed previous attempts in most cases by about 1 order of magnitude. Experiments show that the cross-linking reaction does not counteract the beating effect, as has usually occurred in the past for other cross-linking routes, but instead complements it. The ability ofEDC for promoting covalent bonding under very wet conditions appears to make it an excellent agent for the enhancement of the WWS of paper, the property that ultimately determines the runnability of a papermaking machine. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158886

Why does paper get stronger as it dries? / Alvaro Tejado in Materials today, Vol. 13 N° 9 (Septembre 2010) 

Public ISBD [article]  in Materials today > Vol. 13 N° 9 (Septembre 2010) . - pp. 42–49 Titre : Why does paper get stronger as it dries? Type de document : texte imprimé Auteurs : Alvaro Tejado, Auteur ; Theo G.M. Van de Ven, Auteur Année de publication : 2011 Article en page(s) : pp. 42–49 Note générale : Ingénierie Langues : Anglais (eng) Mots-clés : Paper  Wet  paper  Fiber  Friction  Capillary  forces Index. décimale : 620 Essais des matériaux. Matériaux commerciaux. Station génératrice d'énergie. Economie de l'énergie Résumé : Surprisingly the strength of wet paper is still poorly understood. Here we show that the traditional explanation of the strength of wet paper is incorrect. Observations that the capillary force in fiber crossings in wet paper approaches zero as the water is evaporated show that they are not responsible for the strength of wet paper. Instead we present evidence that fiber entanglements and friction are the cause. Like paper, films made of nanotubes, nanorods, nanofibers or nanoribbons also consist of randomly oriented fibers, and this field may well benefit from an increased knowledge of paper properties. DEWEY : 620 ISSN : 1369-7021 En ligne : http://www.sciencedirect.com/science/article/pii/S1369702110701644 [article] Why does paper get stronger as it dries? [texte imprimé] / Alvaro Tejado, Auteur ; Theo G.M. Van de Ven, Auteur . - 2011 . - pp. 42–49. Ingénierie Langues : Anglais (eng) in Materials today > Vol. 13 N° 9 (Septembre 2010) . - pp. 42–49 Mots-clés : Paper  Wet  paper  Fiber  Friction  Capillary  forces Index. décimale : 620 Essais des matériaux. Matériaux commerciaux. Station génératrice d'énergie. Economie de l'énergie Résumé : Surprisingly the strength of wet paper is still poorly understood. Here we show that the traditional explanation of the strength of wet paper is incorrect. Observations that the capillary force in fiber crossings in wet paper approaches zero as the water is evaporated show that they are not responsible for the strength of wet paper. Instead we present evidence that fiber entanglements and friction are the cause. Like paper, films made of nanotubes, nanorods, nanofibers or nanoribbons also consist of randomly oriented fibers, and this field may well benefit from an increased knowledge of paper properties. DEWEY : 620 ISSN : 1369-7021 En ligne : http://www.sciencedirect.com/science/article/pii/S1369702110701644