The hydrophobisation of activated carbon surfaces by organic functional groups

A technique of hydrophobic surface design with a high degree of structural homogeneity has been developed for catalytic materials. Mesoporous activated carbons and silica gel were modified by (A) treatment with vinyltrimethoxysilane (vtms) or (B) chlorination with carbon tetrachloride followed by reaction with a Grignard reagent. Evidence for silica gel modification was obtained from FT-IR and C-13 NMR spectroscopy and from elemental analysis. Carbons chemically modified with alkanes and olefins were studied using thermogravimetry (TG) and the results compared with those for the modified silica gel. TG and differential scanning calorimetry (DSC) revealed that the polymerisation of vinyl groups occurred on the carbon surface. The participation of the carrier surface in the initiation of radical processes has been discussed.