Low hydrothermal temperature synthesis of porous calcium silicate hydrate with enhanced reactivity SiO2

This study presents a novel approach for the synthesis of porous calcium silicate hydrate (CSH) at a low hydrothermal temperature of 110 °C based on enhanced reactivity SiO2 (i.e. silica/polyethylene glycol (PEG2000) composites) as the source silica material. The as-prepared CSH materials exhibited a porous microstructure with a large number of small mesopores. The porosity formation mechanism of CSH was apparent that cavitation, resulting from sonication, enabled PEG2000 (via intercalation on silica) to break apart Si–O–Si structural units, thereby enhancing SiO2 reactivity at a low hydrothermal temperature. In addition, the presence of PEG2000 effectively prevented the aggregation of particles during the formation process of the porous CSH solid. The low temperature synthesis proposed herein represents a viable and effective method for the further development of porous CSH as a functional ceramic material.