Université de Neuchâtel

The comparison of experimental and calculated pore size distributions of activated carbons

Stoeckli, Fritz ; Guillot, André ; Slasli, Abdou ; Hugi-Cleary, Deirdre

In: Carbon, 2002, vol. 40, no. 3, p. 383-388

Activated carbons are disorganized materials with variable pore size distributions (PSD). If one assumes that the porosity consists mainly of locally slit-shaped micropores, model isotherms can be obtained by computer simulations and used to assess the PSD on the basis of experimental isotherms. In the present study, CO2 isotherms have been measured at 273 K on seven well-characterized...

Université de Neuchâtel

Microporosity in carbon blacks

Stoeckli, Fritz ; Guillot, André ; Slasli, Abdou ; Hugi-Cleary, Deirdre

In: Carbon, 2002, vol. 40, no. 2, p. 211-215

Microporous carbon blacks can be characterized by the same techniques as activated carbons, using the classical DR equation and comparison plots based on non-porous materials. The CO2 adsorption isotherm at 273 K, combined with computer modelling, also leads to an assessment of microporosity. The results agree with independent techniques such as immersion calorimetry into liquids of...

Université de Neuchâtel

Water adsorption by activated carbons in relation to their microporous structure

Slasli, Abdou ; Jorge, M. ; Stoeckli, Fritz ; Seaton, N. A.

In: Carbon, 2003, vol. 41, no. 3, p. 479-486

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...

Université de Neuchâtel

Specific and non-specific interactions between ammonia and activated carbons

Stoeckli, Fritz ; Guillot, André ; Slasli, Abdou

In: Carbon, 2004, vol. 42, no. 8-9, p. 1619-1624

It is shown that the adsorption of NH3 by activated carbons at different temperatures follows Dubinin's theory and, as in the case of water, for carbons with high oxygen contents one observes an upward deviation in the initial section of the DR plot. This indicates a strong primary adsorption, due to specific interactions. At higher relative pressures, this adsorption is followed by a...

Université de Neuchâtel

Modelling of water adsorption by activated carbons: effects of microporous structure and oxygen content

Slasli, Abdou ; Jorge, M. ; Stoeckli, Fritz ; Seaton, N. A.

In: Carbon, 2005, vol. 42, no. 10, p. 1947-1952

The present paper examines the adsorption of water by microporous carbons containing various amounts of surface oxygen and a smaller proportion of basic centres. The modelling of water adsorption for 293 and 310 K, using variable pore size distributions (PSD), confirms that the overall type IV isotherm is the sum of a type I isotherm associated with the specific interactions, and a type V...

Université de Neuchâtel

The characterization of microporosity in carbons with molecular sieve effects

Stoeckli, Fritz ; Slasli, Abdou ; Hugi-Cleary, Deirdre ; Guillot, André

In: Microporous and Mesoporous Materials, 2002, vol. 51, no. 3, p. 197-202

The apparent and the real micropore size distributions (PSDs) of molecular sieve carbons can be assessed by combining the adsorption of CO2 at 273 K with immersion calorimetry into liquids of increasing molecular dimensions. On the basis of model isotherms resulting from computer simulations, the adsorption of carbon dioxide, a relatively small probe, leads to the overall PSD of the...

Université de Neuchâtel

On the Adsorption, by Activated Carbons, of Some Sparingly Soluble Organics from Aqueous Solutions

Hugi-Cleary, Deirdre ; Slasli, Abdou ; Stoeckli, Fritz

In: Helvetica Chimica Acta, 2005, vol. 88, no. 3, p. 470 - 477

Activated carbons play an important role in the purification of air and of water. Whereas vapors are adsorbed by a micropore filling process, the removal of sparingly soluble species such as phenol and its derivatives is limited to the coating of the effective surface of the material. This reduces considerably the sorptive capacity of a given carbon, and a suitable description is needed to...