Szczegóły publikacji

Autor

• AGHMadej Dominika

Słowa kluczowe

Dane bibliometryczne

ID BaDAP	115524
Data dodania do BaDAP	2018-08-06
Tekst źródłowy	URL
DOI	10.1016/j.ica.2018.06.047
Rok publikacji	2018
Typ publikacji	artykuł w czasopiśmie
Otwarty dostęp
Czasopismo/seria	Inorganica Chimica Acta

Abstract

This paper summarizes a reinvestigation of the dehydration and dehydroxylation of synthetic layered (oxy)hydroxides through thermal analysis (TG-DSC-EGA-MS). As well a discussion to the second Pauling’s rule have been done. Simple metal-hydroxides i.e. Mg(OH)2 and Al(OH)3, closely related aluminium oxide hydroxide, AlO(OH) and (Mg-Al-OH) type layered double hydroxides (LDHs) were prepared by different synthesis procedures and evaluated by X-ray diffraction (XRD). According to this research, the thermal stability of hydroxyl groups in synthetic reference layered (oxy) hydroxides is (Al2)-OH-boehmite sites (534 °C) > (Mg2Al)-OH-hydrotalcite sites (432 °C) > (Mg3)-OH-brucite sites (401 °C) > (Mg3)-OH-hydrotalcite sites (330 °C) > (Al2)-OH-gibbsite sites (250 °C) at a heating rate of 10 °C min−1. The reorganization of the hydroxyl groups within the magnesia-alumina hydrating blended pastes was established and evaluated in three aspects. First, the results from EGA-MS reveal that the (Mg3)-OH sites in brucite lattice progressively reorganize and move continuously towards lower temperatures with curing time. Second, the optimized chemical composition of MgO-Al2O3 dry mixture designed as hydrotalcite precursor in corundum-spinel castables is given in mol% as follows 50%MgO-50%Al2O3. Third, the hydrothermal activation strongly accelerates the formation of hydrotalcite Mg6Al2CO3(OH)16·4H2O phase.