Abstract
The mechanisms of speciation of aluminate and silicate phases during dissolution and condensation stages of alumino-silicate geopolymer reactions characterised by Si/Al ≥ 3, have been investigated and the results compared to predictions of the partial charge model. Solid-state nuclear magnetic resonance (NMR) traces indicate that free [Al(OH)4]− species, present in lower silicate formulations such as Si/Al ≤ 1, do not occur in the present systems, suggesting that the condensation reaction between [Al(OH)4]− and silicate species is fairly quick and is consumed as soon as it is formed. This observation is also consistent with both calorimetric measurements and model predictions, as the condensation time increased exponentially with increased Si/Al ratio in the geopolymeric phase, indicating again that the high content of Al species in the gel phase greatly enhanced the condensation rate. The experimental observations suggest that the condensation process in these systems occurs in two stages: (a) quick condensation between aluminate and silicate species; followed by (b) a slow condensation stage solely involving silicate species.
Similar content being viewed by others
References
Davidovits J (1982) US Patent 4349386
Davidovits J, Davidovics M, Davidovits N (1994) US Patent 5342595
Davidovits J, Davidovits R, James C (eds) (1999) Proceedings of geopolymer international conference, Saint-Quentin, France. ISBN 2-902933-14-2J
Lukey G (ed) (2002) In: Proceedings of geopolymer international conference, Melbourne, Australia. ISBN 0-97502242-0-5
van Jaarsveld J, van Deventer JSJ (1999) Cem Concr Res 29: 1189
Phair J, van Deventer JSJ (2001) J Minerals Eng 14:289
Palomo A, Glasser F (1992) Br Ceram Trans J 91:107
Rahier H, van Mele B, Biesemans M, Wastiels J, Wu X (1996) J Mater Sci 31:71
Rahier H, Simons W, van Mele B, Wastiels J (1997) J Mater Sci 32:2237
Palomo A, Blanco-Varela M, Granizo M, Puertas F, Vazquez T, Grutzeck M (1999) Cem Concr Res 29:997
Barbosa V, Mackenzie K, Thaumaturgo C (2000) Int J Inorg Mater 2:309
Weng L, Sagoe-Crentsil K (2005) Dissolution processes, hydrolysis and condensation reactions during geopolymer synthesis: Part I—High Si/Al ratio systems. J Mater Sci (submitted to)
Weng L, Sagoe-Crentsil K, Brown T, Song S (2005) Mater Sci Eng B Solid-State Mater Adv Technol 117(2):163
Henry M, Jolivet J, Livage J (1992) J Struct Bonding 77:153
Swaddle T (2001) Coordination Chem Rev 219–221:665
Provis JL, Duxson P, Lukey GC, van Deventer JSJ (2005) Chem Mater 17(11):2976
Glasser L, Harvey G (1984) J Chem Soc Chem Commun 16:1250
Glasser L, Lachowski E (1980) J Chem Soc Dalton Trans 3:393
Weng L, Sagoe-Crentsil K, Brown T (2002) In: Lukey G (ed) Proceedings of geopolymer international conference, Melbourne, Australia
Duxson P, Provis JL, Lukey GC, Separovic F, van Deventer JSJ (2005) Langmuir 21(7):3028
Engelhardt G, Michel D (1987) High-resolution solid-state NMR of silicates and zeolites. Wiley, Chichester, p 485
Palomo A, Grutzeck M, Blanco M (1999) Cem Concr Res 29:1323
Harris R, Newman R (1977) J Chem Soc Faraday II 73:153
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Sagoe-Crentsil, K., Weng, L. Dissolution processes, hydrolysis and condensation reactions during geopolymer synthesis: Part II. High Si/Al ratio systems. J Mater Sci 42, 3007–3014 (2007). https://doi.org/10.1007/s10853-006-0818-9
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10853-006-0818-9