In order to evaluate the current theories employed to explain hysteresis in
mesoporous solids, scanning sorption behavior was determined for several d
ifferent MCM-41 silicates. Both nitrogen and argon sorption scans at 77 K w
ere studied. Several different scanning behaviors were observed. No single
current theory predicts the behavior observed. (C) 2001 Elsevier Science B.
V. All rights reserved.