e hydrogen-bonded species are eliminated at elevated temperatures under vacuum whereas the isolated ones remain. Loading C60 in the MCM-41 materials greatly changes their dehydroxylation behavior. When the MCM-41:C60 weight ratio is 10:1, at about 400℃ under vacuum, the isolated silanols are reduced to a certain degree whereas the hydrogen-bonded hydroxyls become more resistant to thermal treatment by comparison with those in the parent C60-free samples. Increasing the loading amount of C60 to a MCM-41:C60 weight ratio of 10:3 results in complete removal of both isolated and hydrogen-bonded silanols, at about 350℃. However, the two MCM-41 samples exhibit different infrared spectra at lower evacuation temperatures in the presence of C60, indicative of a discrepancy in the dehydroxylation process between them. It is postulated that during the dehydroxylation, C60 captures hydroxyls from the silanol groups of MCM-41 to form C-H and C-OH species, followed by condensation of the C-OH groups and/or combination of C-OH with C-H.