Synthesis of nanometer enstatite from precursor gels prepared by the geopolymer technique

The geopolymer technique is one of the methods making inorganic polymers which can be prepared by polycondensation of silicic acids complexes containing foreign metal ions. Sodium silicate solutions prepared from Na₂O·SiO₂·9H₂O was applied as host solutions. Anhydrous silicate consisting of MgO and SiO₂ components were synthesized by heat treatment of gel precursors prepared by mixing sodium metasilicate solution with Mg–nitrate solution in various molar ratio. Amorphous and crystalline characters were discussed on the basics of DTA and XRD results. The XRD results showed that gels began to crystallize enstatite at about 900 °C.