Université de Neuchâtel

Adsorption of Phenol from Dilute and Concentrated Aqueous Solutions by Activated Carbons

Fernandez, Elena ; Hugi-Cleary, Deirdre ; López-Ramón, M. Victoria ; Stoeckli, Fritz

In: Langmuir, 2003, vol. 19, no. 3, p. 9719–9723

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...

Université de Neuchâtel

On the use of standard DRK isotherms in Dubinin’s t/F method

Hugi-Cleary, Deirdre ; Stoeckli, Fritz

In: Carbon, 2000, vol. 38, no. 9, p. 1309-1313

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...

Université de Neuchâtel

Prediction of Filter Performances against Organic Vapours: Statistical Analysis of Breakthrough Times as a Basis for a Simple Prediction Model

Lavanchy, André ; Liebi, R. ; Hugi-Cleary, Deirdre ; Stoeckli, Fritz

In: Journal of the International Society for Respiratory Protection, 2005, vol. 22, p. 71-78

The prediction of the protection efficiency of NBC-respiratory filters against organic vapours is often very difficult, especially when strong physical interactions or chemisorption processes are invoved. The presented statistical analysis is an attempt to develop a simple, but reliable, prediction model for breakthrough times. In over 70 experiments run under conditions of the EN 141 guidelines...

Université de Neuchâtel

Dubinin’s Theory: A Versatile Tool in Adsorption Science

Stoeckli, Fritz ; Lavanchy, A. ; Hugi-Cleary, Deirdre

In: Fundamentals of Adsorption, 1998, vol. 6, p. 75-80

The paper presents the main features of Dubinin's theory for the volume-filling of micropores, its direct consequences in the field of immersion calorimelry and recent developments such as the possibility to describe type V isotherms (water on active carbons) with the Dubinin-Astakhov equation, and to deal with multiple adsorption under static and dynamic conditions. It also confirmed that in...

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...