title: Influence of specific surface area of pyrogenic silicas on their heat of immersion in water and on their surface properties assessed using inverse gas chromatography.
abstract: The heat of immersion and the surface properties of pyrogenic silicas were examined using microcalorimetry and inverse gas chromatography at finite concentration (FC-IGC). The microcalorimetric measurements showed a regular decrease of the heat of immersion, in water, per area unit with an increase in the surface areas. The desorption isotherms were established using FC-IGC. It is observed that BET constant value goes through a minimum, whereas the shapes of distribution function of the adsorption energies of isopropanol are changing. All results could be interpreted using a model of formation of the pyrogenic silica in the flame, which explains the change of surface functionality and geometry occurring around 200 m2/g.
authors.affiliation: ENSCMu ENSISA-W, 11, rue Werner Mulhouse Cedex, France. JB.Donnet@univ-mulhouse.fr
authors.forename: Jean-Baptiste
authors.initials: JB
authors.lastname: Donnet
authors.forename: Henri
authors.initials: H
authors.lastname: Balard
authors.forename: Nabila
authors.initials: N
authors.lastname: Nedjari
authors.forename: Boualem
authors.initials: B
authors.lastname: Hamdi
authors.forename: Herbert
authors.initials: H
authors.lastname: Barthel
authors.forename: Torsten
authors.initials: T
authors.lastname: Gottschalk-Gaudig