SYNTHESIS OF A LARGE-PORE PHENYL-MODIFIED MESOPOROUS SILICA AND ITS CHARACTERIZATION BY NITROGEN AND BENZENE SORPTION

Phenyl-modified porous silicas have been synthesized at room temperatu re by the co-condensation of a siloxane and an organosiloxane in the p resence of a surfactant. Mesitylene was employed as a pore swelling ag ent to produce a mesostructured material. The product has been charact erized by powder XRD, nitrogen sorption at 77 K and benzene sorption a t 293 K. Powder XRD data yielded a d(100) spacing of 52.0 Angstrom for the as-synthesized material and 49.5 Angstrom after template removal. Nitrogen sorption is characterized by a type IV isotherm indicating m esoporosity with a BET specific surface area of 942 m(2) g(-1) and a G urvitsch pore volume of 0.67 cm(3) g(-1). Benzene sorption also produc ed a type IV isotherm with a BET specific surface area of 1051 +/- 50 m(2) g(-1) and a Gurvitsch pore volume of 0.75 cm(3) g(-1). The discre pancy in the total pore volume values may be due to the structure of t he adsorbed benzene. Samples produced in the presence of tetradecane o r in the absence of any pore swelling agent have pores in the micropor ous range.