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

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 H-1 NMR, C-13 NMR, Si-29 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 gamma(cmc) and A(min) values. The gamma(cmc) and A(min) 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. (C) 2019 Elsevier B.V. All rights reserved.