Preparation of large-sized analcime single crystals using the Geopolymer-Gels-Conversion (GGC) method

A novel and simple method to fabricate large-sized analcime (ANA) single crystals using the Geopolymer-Gels-Conversion (GGC) method without organic template agents is reported. The results indicate that the hydrothermal time plays an important role in determining the crystals size distribution. By controlling the hydrothermal time, the ANA single crystals with a diameter range of 50-1200 μm, and icositetrahedron architecture can be synthesised. Due to the influence of two silicon sources and the small surface area of the geopolymer bulk, in the hydrothermal crystallisation process, the amorphous three-dimensional network structures of the Na2O-Al2O3-4SiO2 geopolymers were converted into large-sized ANA single crystals.