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Stoeckli, Fritz

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

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  • Publication
    Accès libre
    Adsorption of Phenol from Dilute and Concentrated Aqueous Solutions by Activated Carbons
    (2003)
    Fernandez, Elena
    ;
    Hugi-Cleary, Deirdre
    ;
    López-Ramón, M. Victoria
    ;
    Stoeckli, Fritz 
    Combined calorimetric and adsorption techniques show that in the case of phenol adsorption from either dilute or concentrated aqueous solutions, water is always adsorbed preferentially by the oxygen-containing surface groups of the carbon. This reduces the surface and/or the micropore volume accessible to the phenol molecule and quantitatively explains the decrease in the limiting adsorption of phenol on a given carbon after oxidation. In the case of dilute solutions, as established earlier, the mechanism corresponds to the coating of the total surface (external surface and micropore walls) by a monolayer of phenol. On the other hand, for concentrated solutions (15−25% of water), one observes a process of micropore filling by phenol. Both mechanisms can be described in the framework of Dubinin's theory, which allows predictions based on simple physical and structural parameters.
  • Publication
    Accès libre
    Phenol Adsorption from Dilute Aqueous Solutions by Carbons
    (2003)
    Fernandez, Elena
    ;
    Gotovac, Suzana
    ;
    Hugi-Cleary, Deirdre
    ;
    López-Ramón, M. V.
    ;
    Stoeckli, Fritz 
  • Publication
    Accès libre
    Chars and Activated Carbons Prepared from Asturian Apple Pulp
    (2001)
    Fernandez, Elena
    ;
    Centeno, Teresa A.
    ;
    Stoeckli, Fritz 
    Asturian apple pulp was carbonised under nitrogen at 400ºC and 750ºC and subsequently activated with CO2 at 750ºC. The resulting active carbon exhibited properties in line with those expected from precursors of vegetable origin, with the carbonisation stage appearing to have only a limited influence on the final porosity. In the case of carbonisation at 400ºC, the initial micropore system of the char was accessible to dichloromethane, CO2 and water, but presented a strong gate effect at ca. 0.35-0.40 nm. The pore volume, W0, was equal to 0.13 cm3/g and the average pore width 0.70 nm. The pore size distribution was obtained from CO2 adsorption at 0ºC, using isotherms derived from computer modelling. With the char prepared at 750ºC, the initial porosity was only accessible to water and its presence was confirmed by extrapolation of W0 for the activated carbons.