Longitudinal single-sided NMR study: Silica-to-alumina ratio changes the reaction mechanism of geopolymer

Characterizing and understanding the mechanisms underlying geopolymerization are critical in achieving use of sustainable construction material, geopolymer, for widespread commercial production. Non-destructive 1 H NMR relaxometry can provide novel information about as it allows simultaneous detection where water goes how pore structure changes. Coupled with development single-sided devices, measurements not limited by specimen size therefore able to observe in-situ conditions geopolymer synthesis. Here, curing process metakaolin-based geopolymers was monitored on a device. The silica-to-alumina ratio ( Si / Al ) found affect reaction stages geopolymerization. After dissolution aluminosilicate precursor, low generate three gelation/polymerization well water-binding stage, two gel phases appeared. When varied 1.5–2.5, only one phase observed.