Sorption and pore condensation behavior of pure fluids in mesoporous MCM-48 silica, MCM-41 silica and controlled pore glass.

Beitrag in einer Fachzeitschrift
(Originalarbeit)


Details zur Publikation

Autorinnen und Autoren: Thommes M
Zeitschrift: Studies in Surface Science and Catalysis
Verlag: Elsevier Science B.V.
Jahr der Veröffentlichung: 2001
Band: 135
Heftnummer: Zeolites and Mesoporous Materials at the Dawn of the 21st Century
Seitenbereich: 2893-2901-2901
ISSN: 0167-2991


Abstract

The authors present a systematic study on the sorption and pore condensation behavior of nitrogen and argon in various silica materials (MCM-48, MCM-41 and Controlled Pore Glass (CPG)) at 87 and 77 K. A detailed characterization with respect to surface area, pore vol. and pore size distribution together with a detailed comparison of sorption isotherms in MCM-48 and MCM-41 silica materials of nearly equal pore size was performed. The results show clearly that the shape of sorption isotherms (in particular the shape and the width of sorption hysteresis loops) depend both on temp. and pore diam., i.e. the thermodn. states of pore fluid and bulk fluid, but also strongly on the texture of the porous material. Pore condensation of argon can still be obsd. at 77 K, i.e. ∼6.5 K below the bulk triple point in MCM-48/-41 silica materials with pore diams. < 5 nm, but vanishes at this temp., when the pore diam. exceeds ∼12 nm (CPG). These observations indicate that the triple point of a fluid confined to silica pores is shifted to lower temp. compared to the bulk triple point. [on SciFinder(R)]


FAU-Autorinnen und Autoren / FAU-Herausgeberinnen und Herausgeber

Thommes, Matthias Prof. Dr.
Lehrstuhl für Thermische Verfahrenstechnik

Zuletzt aktualisiert 2019-28-02 um 20:53