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Insights into the structural transformations of aluminosilicate inorganic polymers: a comprehensive solid-state NMR study
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SYSNO ASEP 0379050 Druh ASEP J - Článek v odborném periodiku Zařazení RIV J - Článek v odborném periodiku Poddruh J Článek ve WOS Název Insights into the structural transformations of aluminosilicate inorganic polymers: a comprehensive solid-state NMR study Tvůrce(i) Brus, Jiří (UMCH-V) RID, ORCID
Kobera, Libor (UMCH-V) RID, ORCID
Urbanová, Martina (UMCH-V) RID, ORCID
Koloušek, D. (CZ)
Kotek, Jiří (UMCH-V) RIDZdroj.dok. Journal of Physical Chemistry C. - : American Chemical Society - ISSN 1932-7447
Roč. 116, č. 27 (2012), s. 14627-14637Poč.str. 11 s. Jazyk dok. eng - angličtina Země vyd. US - Spojené státy americké Klíč. slova inorganic polymers ; phase transition ; water Vědní obor RIV CF - Fyzikální chemie a teoretická chemie CEP GAP108/10/1980 GA ČR - Grantová agentura ČR IAA400400904 GA AV ČR - Akademie věd Institucionální podpora UMCH-V - RVO:61389013 CEZ AV0Z40500505 - UMCH-V (2005-2011) UT WOS 000306303800050 DOI 10.1021/jp300181q Anotace To clarify the problem of undesired crystallization of amorphous aluminosilicate inorganic polymers (AIPs), we used 27Al MQ/MAS spectroscopy that revealed a two-component character of the prepared AIPs. The prevailing fraction of [AlO4]− species (amorphous phase) is charge-balanced by Na+counterions and exhibits considerable distribution of 27Al chemical shifts induced by the variation of Al−O−Si valence angles. In contrast, the minor fraction of [AlO4]− tetrahedra, which can be attributed to the partially ordered domains, shows a broad distribution of quadrupolar parameters that result from variability in the chemical nature of counterions. The partially ordered domains of the phase-unstable AIPs contained a considerably larger amount of [AlO4]− species charge-balanced by H+. Therefore, we assume that the destabilization of AIPs is associated with the presence of bridging hydroxyl groups (Si−OH+−Al, Brønsted-acid sites) that induce breaking of Si−O−Al bonds. Pracoviště Ústav makromolekulární chemie Kontakt Eva Čechová, cechova@imc.cas.cz ; Tel.: 296 809 358 Rok sběru 2013
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