Study of the formation of acid‐based geopolymer networks and their resistance to water by time/temperature treatments

Acid-based geopolymers are known for their high temperature resistance and good mechanical performances. Some compositions also exhibit water resistance, which make them suitable outdoor applications. This work aims to understand accurately the steps occurring during geopolymerization process focuses on type of networks forming at early stages reaction. The sample, prepared from metakaolin phosphoric acid, has been analyzed different durations temperatures its solidification, in order identify compounds would crystallize. structural characterizations have performed using Fourier transform infrared spectroscopy X-ray diffraction. Several Al–O–P especially AlPO4 polymorphs crystallize these conditions. They belong three families aluminophosphates a reliable indication amorphous organization original sample. first one is similar phases that appear phase transition sequences silica, second composed AlPO4-based zeolites, last characterized by presence aluminum an octahedral network. transitions between discussed. Finally, calcined samples improved, release acidic species limited even after calcination low temperature.