Positive curvature effects and interparticle capillary condensation during nitrogen adsorption in particulate porous materials.
The adsorption of nitrogen in a collection of spheres that touch or merge in a sintering-like manner is modeled using a Derjaguin-Broeckhof-de Boer approach. The proposed model accounts for both positive curvature effects and for capillary condensation at the contact between two spheres. A methodology is proposed to fit the P/P(0)>0.4 adsorption region with the coordination number of the spheres as the only adjustable parameter. The use of the model is illustrated on a series of silica aerogels. The suitability of various standard isotherms needed for the modeling is also discussed.
Gommes
Cedric J
CJ
Department of Chemical Engineering, University of Liège, Allée du 6 Août 3, B-4000 Liège, Belgium. cedric.gommes@ulg.ac.be
Ravikovitch
Peter
P
Neimark
Alexander
A