Synthesis, aggregation behavior of polyether based carbosilane surfactants in aqueous solution

Abstract

Novel polyether based carbosilane surfactants with different hydrophobic groups (Me-Si2C-EO8, Et-Si2C-EO8, and Ph-Si2C-EO8) were successfully synthesized and confirmed by 1H NMR, 13C NMR, 29Si NMR, and FT-IR. Aggregation behavior of the polyether based carbosilane surfactants in aqueous solution was investigated by surface tension, dynamic light scattering (DLS), transmission electron microscopy (TEM). The additional CH2 group between silicon atoms can increase the Lifshitz-van der Waals forces for carbosilane hydrophobic groups and directly increases the γcmc and Amin values. The γcmc and Amin values follow the order, Me-Si2C-EO8 < Et-Si2C-EO8 < Ph-Si2C-EO8, owing to the introduction of ethyl, phenyl group to carbosilane hydrophobic groups which can obviously increase their molecular volumes and hydrophobicities. All the investigated carbosilane surfactants can self-assemble into spherical aggregates with size distribution ranges from 50 to 400 nm in aqueous solution.