Studies on the Gemini Type Amphipathic Surfactants(4);Surface Active Properties of Amphipathic Compound with Two Sulfate Groups and Two Lipophilic Alkyl Chains
Surface active properties of these aqueous Gemini surfactant solutions including surface tension, critical micelle concentration(cmc), foaming power, foam stability, emulsifying power and Krafft point were measured at given conditions. They showed excellent properties, being compared with conventional single-chain surfactants such as sodium dodecyl sulfonate(SDS). Their surface tensions in the aqueous solutions were decreased to 30~38 mN/m, which is lower than 39 mN/m of SDS, and their cmc values evaluated by surface tension method were 2.8×10-5~3.3×10-4 mol/L. These values were also much lower than that of SDS, 9.8×10-3 mol/L. The foaming power and foam stability, especially decyl and dodecyl compounds, were good and the emulsifying power in benzene or soybean oil was also excellent. All of the synthesized Gemini surfactants possessed good water solubility and their Krafft points were all below 0℃. As results, DDED and DDOD, Gemini surfactants which were synthesized are expected to be applied as foamers, emulsifiers and so on.