Gas Sorption: Isotherm Type V >Highly uncommon > Exhibited by mesoporous solids P//PO >Exhibited by nonporous solids ype with an almost completely uniform surface PIPO S. Lowell J. E. Shields, Powder Surface Area and Porosity, 3rd Ed. Chapman Hall, New York, 1991 http://nano.materials.drexel.edu Gas Sorption: Hysteresis Hysteresis P/PO > Hysteresis indicates the presence of mesopores >Hysteresis gives information regarding pore shapes Types l, ll and ll isotherms are generally reversible but type an have a hysteresis Types IV and V exhibit hysteresis S Lowell J. E. Shields, Powder Surface Area and Porosity, 3rd Ed Chapman Hall, New York, 199112 http://nano.materials.drexel.edu Gas Sorption: Isotherm Va P/Po 1 Type V P/Po 1 Type VI ¾Highly uncommon ¾Exhibited by mesoporous solids ¾Exhibited by nonporous solids with an almost completely uniform surface S. Lowell & J. E. Shields, Powder Surface Area and Porosity, 3rd Ed. Chapman & Hall, New York, 1991 Va http://nano.materials.drexel.edu Gas Sorption: Gas Sorption: Hysteresis Hysteresis ¾Hysteresis indicates the presence of mesopores. ¾Hysteresis gives information regarding pore shapes . ¾Types I, II and III isotherms are generally reversible but type I can have a hysteresis. Types IV and V exhibit hysteresis. P/Po 1 Hysteresis Va S. Lowell & J. E. Shields, Powder Surface Area and Porosity, 3rd Ed. Chapman & Hall, New York, 1991