SYNTHESIS OF MESOPOROUS SILICA MATERIALS (MCM-41) USING SILICA FUME AS THE SILICA SOURCE IN A BINARY SURFACTANT SYSTEM ASSISTED BY POST-HYDROTHERMAL TREATMENT AND ITS PB2+ REMOVAL PROPERTIES

Mesoporous silica materials (MCM-41) were successfully prepared by substituting silica fume for silicate in different surfactant systems. The effects of binary surfactant systems and post-hydrothermal treatment on the morphology and structural properties of MCM-41 were investigated based on X-ray diffraction (XRD), N-2 sorption/desorption, and transmission electron microscopy analyses (TEM). The results confirmed that polyethylene glycol (PEG-6000) is an effective additive template in a binary surfactant system for the synthesis of mesoporous silica materials. Meanwhile, the hydrothermal stability of the mesoporous silica materials can be improved by post-hydrothermal treatment and the optimal experimental parameters are a temperature of 140 degrees C and a treatment time of 48 h. The formation of high-quality MCM-41 is based on the balance between the ordered assembly of the inorganic anionic species and cationic surfactant, in accordance with the electrostatic interactions and hydrogen bonds between PEG-6000 and the inorganic species. Meanwhile, Pb(II) removal from aqueous solution has also been examined using MCM-41 as an adsorbent. The results of adsorption showed that the as-synthesized MCM-41 demonstrated a high capacity of Pb2+.