caa a22 4500 463225449 CHVBK 20180405153225.0 cr unu---uuuuu 170326e20070601xx s 000 0 eng 10.1007/s10853-006-0173-x doi (NATIONALLICENCE)springer-10.1007/s10853-006-0173-x Formation of aluminosilicate geopolymers from 1:1 layer-lattice minerals pre-treated by various methods: a comparative study [Elektronische Daten] [Kenneth MacKenzie, Dan Brew, Ross Fletcher, R. Vagana] Materials resembling aluminosilicate geopolymers have been prepared from the kaolinitic 1:1 layer lattice aluminosilicate clay mineral halloysite by reaction with sodium silicate solution under alkaline conditions. The effect on geopolymer formation of pretreating the clay mineral reactant by heating, high-energy grinding or exposure to acid or alkali was monitored by the ability of the samples to cure and harden, and by XRD, 27Al and 29Si solid-state MAS NMR spectroscopy. Only samples prepared from the fully thermally dehydroxylated clay showed the typical XRD and NMR geopolymer characteristics. Less complete reaction was found in samples pretreated by highly energetic grinding, whereas samples exposed to chemical pretreatment with dilute acid did not react to form viable geopolymers. Pretreatment with dilute alkali produced a zeolite which reacted with sodium silicate, but the hardened sample was not X-ray amorphous and showed subtle differences in its NMR spectra. These results are discussed in terms of the vital role played in the early stages of the reaction sequence by the presence of labile aluminium. The efficacy of the various pretreatment methods is related to their ability to render the aluminium source (the solid aluminosilicate clay) sufficiently soluble in alkali. Springer Science+Business Media, LLC, 2007 MacKenzie Kenneth School of Chemical and Physical Sciences, Victoria University of Wellington, Laby Building, Kelburn Parade, P.O. Box 600, Wellington, New Zealand aut Brew Dan Department of Chemistry, School of Engineering and Physical Sciences, University of Aberdeen, AB24 3UE, Aberdeen, Scotland aut Fletcher Ross New Zealand Institute for Industrial Research and Development, P.O. Box 31-310, Lower Hutt, New Zealand aut Vagana R. School of Chemical and Physical Sciences, Victoria University of Wellington, Laby Building, Kelburn Parade, P.O. Box 600, Wellington, New Zealand aut Journal of Materials Science Kluwer Academic Publishers-Plenum Publishers; http://www.springer-ny.com 42/12(2007-06-01), 4667-4674 0022-2461 42:12<4667 2007 42 10853 https://doi.org/10.1007/s10853-006-0173-x text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10853-006-0173-x text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- MacKenzie Kenneth School of Chemical and Physical Sciences, Victoria University of Wellington, Laby Building, Kelburn Parade, P.O. Box 600, Wellington, New Zealand aut NATIONALLICENCE 700 1- Brew Dan Department of Chemistry, School of Engineering and Physical Sciences, University of Aberdeen, AB24 3UE, Aberdeen, Scotland aut NATIONALLICENCE 700 1- Fletcher Ross New Zealand Institute for Industrial Research and Development, P.O. Box 31-310, Lower Hutt, New Zealand aut NATIONALLICENCE 700 1- Vagana R. School of Chemical and Physical Sciences, Victoria University of Wellington, Laby Building, Kelburn Parade, P.O. Box 600, Wellington, New Zealand aut NATIONALLICENCE 773 0- Journal of Materials Science Kluwer Academic Publishers-Plenum Publishers; http://www.springer-ny.com 42/12(2007-06-01), 4667-4674 0022-2461 42:12<4667 2007 42 10853 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer