Documents disponibles écrits par cet auteur

Study of ion cluster reorientation process of geopolymerisation reaction using semi-empirical AM1 calculations / Zhang Yunsheng in Cement and concrete research, Vol. 39 N° 12 (Décembre 2009) 

Public ISBD [article]  in Cement and concrete research > Vol. 39 N° 12 (Décembre 2009) . - pp. 1174-1175 Titre : Study of ion cluster reorientation process of geopolymerisation reaction using semi-empirical AM1 calculations Type de document : texte imprimé Auteurs : Zhang Yunsheng, Auteur ; Jia Yantao, Auteur ; Wei Sun, Auteur Année de publication : 2010 Article en page(s) : pp. 1174-1175 Note générale : Génie Civil Langues : Anglais (eng) Mots-clés : Geopolymeric  cement;  Ion  clusters  reorientation;  Semi-empirical  AM1  calculations Index. décimale : 691 Matériaux de construction. Pièces et parties composantes Résumé : In this paper all the possible reaction pathways involved in ion clusters reorientation process of metakaolin based Geopolymeric cement were systemically investigated according to thermodynamic theory. The reaction energy of every possible reorientation pathway was also calculated using computational chemistry method-semi-empirical AM1 calculation. The optimum reorientation pathway was analyzed based on the energy-minimized principle. The calculation results showed that Si–Al hybrid reorientation should be primary reorientation pathway of Geopolymeric cement made with NaOH or KOH activated metakaolin. This viewpoint was also verified by Nuclear Magnetic Resonance Spectroscopy equipped with Magic Angle Spinning technique (MAS-NMR). In addition, the semi-empirical AM1 calculations revealed that the reorientation reaction is easier and stronger in NaOH solution than in KOH solution. DEWEY : 620.13 ISSN : 0008-8846 En ligne : http://www.sciencedirect.com/science/article/pii/S0008884609001823 [article] Study of ion cluster reorientation process of geopolymerisation reaction using semi-empirical AM1 calculations [texte imprimé] / Zhang Yunsheng, Auteur ; Jia Yantao, Auteur ; Wei Sun, Auteur . - 2010 . - pp. 1174-1175. Génie Civil Langues : Anglais (eng) in Cement and concrete research > Vol. 39 N° 12 (Décembre 2009) . - pp. 1174-1175 Mots-clés : Geopolymeric  cement;  Ion  clusters  reorientation;  Semi-empirical  AM1  calculations Index. décimale : 691 Matériaux de construction. Pièces et parties composantes Résumé : In this paper all the possible reaction pathways involved in ion clusters reorientation process of metakaolin based Geopolymeric cement were systemically investigated according to thermodynamic theory. The reaction energy of every possible reorientation pathway was also calculated using computational chemistry method-semi-empirical AM1 calculation. The optimum reorientation pathway was analyzed based on the energy-minimized principle. The calculation results showed that Si–Al hybrid reorientation should be primary reorientation pathway of Geopolymeric cement made with NaOH or KOH activated metakaolin. This viewpoint was also verified by Nuclear Magnetic Resonance Spectroscopy equipped with Magic Angle Spinning technique (MAS-NMR). In addition, the semi-empirical AM1 calculations revealed that the reorientation reaction is easier and stronger in NaOH solution than in KOH solution. DEWEY : 620.13 ISSN : 0008-8846 En ligne : http://www.sciencedirect.com/science/article/pii/S0008884609001823