A New Nonsurfactant Pathway to Mesoporous Silica Materials Based on Tartaric Acid in Conjunction with Metallic Chloride

Mesoporous silica materials have been prepared via the sol−gel reactions of tetraethyl orthosilicate through a new nonsurfactant pathway based on organic compound tartaric acid in conjunction with metallic chloride such as magnesium chloride or aluminum chloride as templates or pore-forming agents. The mesoporous silica materials were obtained upon the removal of the pore-forming agents by extraction with ethanol from the sol−gel composites. The effect of the metallic chloride amount in the synthesis on the physicochemical properties of the porous silica materials is investigated. The results from nitrogen sorption isotherms, transmission electron microscopy, and powder X-ray diffraction indicate that the pore volumes and pore diameters of the extracted samples generally rise with the increase of the amount of the metallic chloride. The results also show that magnesium chloride and aluminum chloride are more effective than sodium chloride in the pore-forming for the preparation of mesoporous materials. The analyses from X-ray fluorescence and infrared spectrometry indicate that the magnesium and aluminum atoms coordinate with the carboxylate anions of tartaric acid and consequently the coordination complexes act as the pore-forming agents.