Number: 2006-021-2-100
Title: Liquid intrusion and alternative methods
for the characterization of macroporous solids
Task Group
Chairman: Jean
Rouquerol
Members: Gino
Baron, Renaud Denoyel,
Herbert Giesche,
Johan Groen, Peter
Klobes, Pierre Levitz,
Alex Neimark, Sean
Rigby, Kenneth S.W.
Sing, Matthias Thommes,
and Klaus Unger
Objective:
To analyse the various liquid intrusion techniques available to-day
to assess the pore-size of materials (with special attention to the
pores above 50 nm width), together with other alternatives, in order
to provide (i) a critical and comparative appraisal and (ii) an appreciation
about the ways which should be favoured and developed to solve the
issue described hereafter.
Description:
The issue raised was made clear at the occasion of the 1st International
Workshop on Macro/Mesopore Analysis: Mercury Porosimetry and Alternative
Liquid Penetration Techniques organized by M. Thommes and R. Denoyel
in Aix-en-Provence (30-31 May 2005): it is all at once environmental
and technical.
The principal method used today to analyse the macropore
range (i.e. above 50 nm width) is indeed the mercury intrusion method,
where the handling of mercury, the inevitable spills and the need
to recycle the mercury polluted by the sample do raise a health and
environmental problem. Both the improvement of the mercury intrusion
approach and its replacement by other methods raise technical issues.
The aim of this project is to provide a first step towards
satisfactory answers, by listing, examining and evaluating all trials
already made in the field. These include the intrusion of safer liquids
(other molten metals, water, organics
) and also the extension
of the analysis of capillary condensation data up to the macropore
range where, for technical reasons it was, until recently, considered
inapplicable. In any case, the need of improvement and/or of alternative
methods is urgent. By clarifying the situation, this project should
help selecting and developing the most promising approaches. The issue
concerns most scientists and industrialists working with porous materials
(catalysts, pharmaceuticals, building materials, stones of ancient
monuments to be restored or protected, adsorbents for chromatography,
liquid purification or gas separation
) and it needs an evaluation
accepted and used by all persons involved all over the world.