Three silicone surfactants, 3-tris(trimethylsiloxy)silylpropyl sulfonate with different alkaline counterions (lithium, sodium, and potassium), were synthesized for the first time. Their chemical structures were confirmed by FT-IR spectra, H NMR, and ESI-MS, and their behaviors in aqueous solutions were investigated by surface tensiometry, electrical conductivity, dynamic light scattering, and different transmission electron microscopy techniques. These anionic silicone surfactants exhibited remarkable surface activity and could reduce the surface tension of water to as low as 19.8 mN/m at the critical aggregate concentration (CAC). The adsorption and aggregation behaviors of these surfactants were assessed by determining the adsorption efficiency, minimum average area per surfactant molecule, and thermodynamic parameters. The cryo-TEM results verified that these molecules could form vesicles in water above the CAC. Moreover, the lowest surface tension, the smallest CAC value, and the largest aggregate size have been reached with potassium counterions. Thus, the different behavior of these surfactants in water can be explained by the different sizes of the hydrated ions.

Silicone surfactants consist of siloxane or carbosilane hydrophobic groups that possess better surface activity compared with alkane surfactants. The surfactants, containing Si atoms which bring excellent bond flexibility and low cohesive energy properties are a promising class of materials for unique surface working, but there are few studies to elaborate their surface activity mechanism with regard to the molecular architecture. Herein, two novel carboxylate surfactants with different silicone hydrophobic groups (Si–O–Si and Si–C–Si) were synthesized and their surface activities, aggregate behaviors, and solution stabilities were systematically investigated. Results showed that both surfactants had excellent surface activities which are attributed to the hydrophobic structure of silicone. The hydrolysis resistance of the carbosilane-based carboxylate surfactant was better than that of the siloxane-based carboxylate surfactant. The differences in hydrolysis processes for the surfactants were confirmed by the mass spectrum and kinetic analysis. Meanwhile, the aggregation number of Si–C–Si surfactants was also determined by the fluorescence quenching method for the first time.

The first recyclable sulfone-containing polysiloxanes were synthesized via an anionic ring-opening polymerization of macroheterocyclic siloxane monomers.

A series of sulfonate-based silicone surfactants with different hydrophobic groups were synthesized. Two synthetic strategies are introduced to permit exquisite control over the hydrophobic moieties. Solution behavior of these surfactants was investigated by surface tensiometry, electrical conductivity, transmission electron microscopy, and dynamic light scattering. The results indicate that the aqueous behavior of the surfactants was distinctly influenced by the hydrophobic groups. Subtle distinctions in surfactant-related properties, which can be attributed to the three-dimensional molecular structures of the surfactants, can be seen for compounds with different hydrophobic moieties. Contact angle results of these surfactants indicate that they have super dispersal ability with the potential value in agriculture.