Abstract for presentation at Chemeca 2007

17O MQMAS NMR characterisation of geopolymers

  • P Duxson, Univeristy of Melbourne, Australia
  • J D Gehman, University of Melbourne, Australia
  • Claire White, University of Melbourne, Australia
  • Dr John Provis, University of Melbourne, Australia
  • F Separovic, University of Melbourne, Australia
  • Z Gan, Center for Interdisciplinary Magnetic Resonance, United States
  • Jannie van Deventer, University of Melbourne, Australia

    • Geopolymers are a class of aluminosilicate materials with the potential to act as a replacement for traditional cements and ceramics in a number of applications. Selective enrichment of 17O in the geopolymeric binder phase provides the opportunity to analyse specifically the newly-formed binder, without interference from unreacted aluminosilicate source materials. Details of the coordination structure of the geopolymer gel network may, therefore, be determined by 17O MQMAS NMR at high field (19.6T): specifically, the presence and relative abundances of Si-O-Al, Si-O-Si and Al-O-Al linkages. Small quantities of non-bridging oxygen sites are observed in some samples, and the reasons for their presence are discussed in terms of the chemistry of the gel and solution phases present during geopolymer synthesis. The implications of the relative abundances of different types of T-O-T (T: tetrahedral Si and/or Al) linkages on the properties and performance of geopolymers are also analysed, and discussed in terms of their predicted effects on durability.

    Conference Organiser - ICMS Pty Ltd