Vignette d'image

Stoeckli, Fritz

Nom
Stoeckli, Fritz
Affiliation principale
Fonction
Professeur.e émérite
Email
fritz.stoeckli@unine.ch
Identifiants
https://libra.unine.ch/handle/123456789/471

Résultat de la recherche

Filtres

4
4
4
Réinitialiser les filtres

Paramètres

Voici les éléments 1 - 4 sur 4
  • Publication
    Accès libre
    Water adsorption by activated carbons in relation to their microporous structure
    (2003)
    Slasli, Abdou
    ;
    Jorge, M.
    ;
    Stoeckli, Fritz 
    ;
    Seaton, N. A.
    The present paper examines the adsorption of water by microporous carbons in the absence of specific interactions. The modelling of water adsorption for 293 and 310 K, using variable pore size distributions (PSD), shows that the type V isotherms follow the Dubinin–Astakhov (DA) equation and fulfill the requirement for temperature invariance. Furthermore, the parameters of the DA equation can be related in a simple way to structural properties of the model carbons. For a number of well-characterized carbons, the type V isotherms generated by combining model isotherms with the corresponding PSDs are in good agreement with the limiting isotherms at 293 and 310 K derived on the basis of a recent development of Dubinin’s theory. This approach will provide the basis for further studies including specific interactions.
  • Publication
    Accès libre
    On the use of standard DRK isotherms in Dubinin’s t/F method
    (2000)
    Hugi-Cleary, Deirdre
    ;
    Stoeckli, Fritz 
    It is shown that the adsorption of benzene, carbon tetrachloride, dichloromethane and nitrogen by a typical non-porous carbon black follows the Dubinin–Radushkevich–Kaganer equation. The requirement for temperature invariance is fulfilled, with an average characteristic energy Eo=10.8 kJ mol−1. This expression is compared with the standard isotherms for benzene and carbon tetrachloride at 293 K proposed by Dubinin and used as a reference in the so-called t/F method, which leads to the non-porous surface area of active carbons. It appears that Dubinin’s isotherm contains inconsistencies, which are compensated for internally. Alternative DRK expressions, applicable to different vapours, are therefore proposed. The present study also shows the limits of Dubinin’s method with respect to comparison plots at higher relative pressures.
  • Publication
    Accès libre
    Recent developments in Dubinin's theory
    (1998)
    Stoeckli, Fritz 
    Dubinin's theory, developed in successive stages between 1947 and 1971 and extended to immersion calorimetry in the 1980s, has recently found new applications. It has been shown that water adsorption by microporous carbons, corresponding to type IV and V isotherms, can be described by the Dubinin-Astakhov (D-A) equation. The extension to immersion calorimetry is also valid and provides information on the interaction between water and oxygen-containing surface groups. The D-A equation has also been combined successfully with the theory of Myers and Prausnitz, which leads to a satisfactory description of static and dynamic adsorption of binary mixtures by active carbon beds.
  • Publication
    Accès libre
    On the characterization of microporous carbons by immersion calorimetry alone
    (1997)
    Stoeckli, Fritz 
    ;
    Centeno, Teresa A.
    Immersion calorimetry is a useful tool for the characterization of solid surfaces in general, but in the case of microporous solids it usually requires complementary information, obtained from an adsorption isotherm. This article demonstrates the possibilities and the limitations of this technique when used alone. It appears that the use of a standard value for the enthalpy immersion does not always provide a reliable assessment of the total surface area.