caa a22 4500 463223888 CHVBK 20180405153221.0 cr unu---uuuuu 170326e20070501xx s 000 0 eng 10.1007/s10853-006-0521-x doi (NATIONALLICENCE)springer-10.1007/s10853-006-0521-x Semi-empirical AM1 calculations on 6-memebered alumino-silicate rings model: implications for dissolution process of metakaoline in alkaline solutions [Elektronische Daten] [Zhang Yunsheng, Sun Wei] In order to investigate the dissolution process of metakaline in alkaline solutions, two 6-memebered rings models consisting of AlO4 tetrahedron and SiO4 tetrahedron, respectively are firstly proposed to represent the structure of metakaoline in this paper. Analysis of the dissolution mechanism of the two 6-memebered rings models in strongly solution reveals that the dissolution process of metakaoline is composed of ring breakage for releasing HOTO 3 ≡ anion, formation of HO-T(OM)3 by ion-pairing reaction between HOTO 3 ≡ anion and M+ cation, and further interaction between the remaining broken ring cluster and MOH solutions. A computational chemistry method: Semi-empirical AM1 calculation is then conducted on the two models to obtain the details of three steps involved in dissolution process. The calculated results showed that 6-member ring model consisting of AlO4 tetrahedron is more reactive than 6-member ring model consisting of SiO4 tetrahedron. Compared with local environment, strongly alkaline accelerated the dissolution of 6-member ring model consisting of SiO4 tetrahedron. Na+ has stronger ion-pairing interaction than K+. The further reaction between the remaining broken ring cluster and strongly alkaline solution depended on the types of the remaining broken ring cluster and alkaline solution. The above results enhanced our understanding of dissolution mechanisms of metakaoline in highly alkaline solutions, which is especially important to geopolymerization reaction. Springer Science+Business Media, LLC, 2007 Yunsheng Zhang Department of Materials Science and Engineering, Southeast University, 210096, Nanjing, P.R. China aut Wei Sun Department of Materials Science and Engineering, Southeast University, 210096, Nanjing, P.R. China aut Journal of Materials Science Kluwer Academic Publishers-Plenum Publishers; http://www.springer-ny.com 42/9(2007-05-01), 3015-3023 0022-2461 42:9<3015 2007 42 10853 https://doi.org/10.1007/s10853-006-0521-x text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10853-006-0521-x text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Yunsheng Zhang Department of Materials Science and Engineering, Southeast University, 210096, Nanjing, P.R. China aut NATIONALLICENCE 700 1- Wei Sun Department of Materials Science and Engineering, Southeast University, 210096, Nanjing, P.R. China aut NATIONALLICENCE 773 0- Journal of Materials Science Kluwer Academic Publishers-Plenum Publishers; http://www.springer-ny.com 42/9(2007-05-01), 3015-3023 0022-2461 42:9<3015 2007 42 10853 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer