Surface properties of dimethylsilylated silicas, assessed using IGC at finite concentration

The specific surface area of silicas samples modified by controlled silylation with dimethyldichlorosilane were assessed by inverse gas chromatography at finite concentration, using isopropanol and water as probes. If isopropanol assesses the whole residual free silica surface, water addresses only the more hydrophilic sites, present at the silica surface. It was also established that the heat of immersion in water of these silylated samples, in water measured by microcalorimetry, is clearly related to the residual free silica surface, delivered by IGC measurement.