Influence of the geological history, particle size and carbonate content on the surface properties of talc as determined by inverse gas chromatography at infinite dilution

Inverse gas chromatography at infinite dilution (IGC-ID) coupled with a controlled impregnation by polymer gives access to information about the surface of heterogeneous solids such as talcum powder. A limitation of IGC-ID is that it is mainly sensitive to the high-energy sites, in other words for the talc, to the lateral surfaces. Thus, a progressive impregnation of the surface of talc with a suitable polymer allows saturating the high-energy sites, making the chromatographic probes access less energetic free sites, specifically the basal surfaces. In this paper, impregnation has been made with polyethyleneglycol (PEG) 20000M and allows estimation of the ratio of basal to lateral surface of talc crystals which plays a very important role in many industrial applications for talc. We examine the influence of several parameters on the surface properties of different types of talc. These parameters are the particle morphology of talc (microcrystalline, lamellar or very lamellar structure), the carbonate content and the particle size.