Synthesis and physicochemical properties of silicon-based gemini surfactants

In this study, polydimethylsiloxane, polyethylene glycol, and various fatty alcohol (m = 0, 6, 12, 18) were employed to produce a series of functional silicon-based gemini surfactants (2CmPSi). Subsequently, surface properties such as surface tension, contact angle, fluorescence, foaming property, dispersion, and emulsion ability were tested. The surface excess concentration (ΓCMC) and the surface area occupied by the surfactant molecule (ACMC) were calculated. Furthermore, we used UV–vis spectroscopy to study the interactions of dye with the silicon-based Gemini surfactants in aqueous solution. The experimental results show that the series of products all possess good surface activity, and the product with 12 carbon chains is best one. In addition, products with long hydrophobic chains and dispersed dyes merge into a complex, shifting the maximum absorption (λmax) toward long wavelengths to produce a red shift effect.