SILICON-MODIFIED CARBOHYDRATE SURFACTANTS VII - IMPACT OF DIFFERENT SILICON SUBSTRUCTURES ON THE WETTING BEHAVIOR OF CARBOHYDRATE SURFACTANTS ON LOW-ENERGY SURFACES - DISTANCE DECAY OF DONOR-ACCEPTOR FORCES

The wetting behaviour of carbohydrate surfactants bearing siloxane, ca rbosilane, polysilane or silane moieties has been investigated. By sta tic surface tension (gamma(lv), sigma) and wetting tension (gamma(sv)- gamma(sl), alpha) measurements on a non-polar perfluorinated surface ( FEP(R)), the contact angles of aqueous surfactant solutions above the critical micelle formation concentration (cmc) were determined. Surfac e tension and wetting tension react independently on defined changes i n the chemical structure of the surfactant molecules. Siloxane surfact ants reduce the surface tension most effectively, whereas for a neopen tyl-substituted silane derivative the lowest solid/liquid interfacial tension was found. The data for isomeric siloxanes, carbosilanes and s ilanes suggest that donor-acceptor forces at solid interfaces have a m aximum range of about 4.5 Angstrom. (C) 1998 John Wiley & Sons, Ltd.