Preparation and surface activity of polyoxyethylene-carboxylated modified Gemini surfactants

In this study we prepared a series of polyoxyethylene-carboxylated modified Gemini surfactants. These surfactants possess two identical hydrophobic groups and multiple hydrophilic groups in their structures. The two hydrophobic alkyl chains were appended to maleic anhydride through condensation with polyoxyethylenated stearyl ether; multiply anionic hydrophilic moieties were obtained after modifying the polyoxyethylenated stearyl ether units with fumaric acid groups to form carboxylate group-containing addition products. The structures of these compounds were confirmed through infrared and nuclear magnetic resonance spectroscopic and elemental analyses. The surfactants exhibit excellent surface activities, low-foaming, wetting power, self-sequestering, and fluorescence properties.