Synthesis and Properties of a Cationic Gemini Surfactant with the Hydrophenanthrene Structure

A novel cationic gemini surfactant with the hydrophenanthrene structure has been synthesized from dehydroabietylamine. Its structure was confirmed by IR, 1 H NMR, and elemental analysis. The critical micelle concentration (CMC) of the surfactant and its surface tension at the CMC ( γ CMC ) in aqueous solution were about 1.58 × 10 −5 mol L −1 and 36.6 mN m −1 at 25 °C, respectively. The emulsion composed of equal amounts of benzene and an aqueous solution with 0.1 % gemini surfactant as emulsifier maintained its stability for 8.5 h. Meanwhile, the antimicrobial activities of the gemini surfactant against Pseudomonas aeruginosa , Escherichia aerogenes , and Staphylococcus epidermidis were much better than those of bromogeramine and ampicillin sodium against the same bacteria, and its minimum inhibitory concentrations (MIC) were 16, 32, and 4 μg mL −1 , respectively.