Synthesis of nanostructured magnesium silicate with high surface area and mesoporous structure

Nanostructured magnesium silicate with high BET surface area and mesoporous structure was prepared by a hydrothermal method using polyethylene glycol (PEG) as surfactant and magnesium nitrate and sodium silicate aqueous solution as magnesium and silicate sources, respectively. The effects of different parameters such as hydrothermal treatment, reaction temperature, pH, ethanol/PEG ratio and etc. on the structural properties of the synthesized sample were examined. The prepared samples were characterized by X-ray diffraction (XRD), N2 adsorption (BET) and scanning electron microscopy (SEM) techniques. The results indicated that hydrothermal treatment increased BET surface area from 290 to 394.2 m2/g and transfer amorphous phase to crystalline. Also, increasing in aging temperature, aging time, pH value and ethanol/PEG ratio did not change surface area by specific procedure, whereas increasing calcination temperature decreased surface area. Furthermore, hydrothermal treatment and increasing in pH value will change hysteresis loop. The highest BET surface area obtained in this paper is 619.8 m2/g.