Synthesis And Properties Of X-type Alkyl Sulfonate Gemini Surfactants

Surfactant，known as“Industrial Monosodium Glutamate”, has been widely applied inmany fields. It has made great contribution to China’s economic and social development.Nowadays, Gemini surfactant has been emerged. It has high performance, however, itssynthetic route is long, production rate is low and cost is high, so these shortcomings hinderedthe industrialization of Gemini surfactants.A series of X-type alkyl sulfonate Gemini surfactants were synthesized by a simplemethod. Four X-type Gemini surfactants were three kinds of surfactants with different lengthof carbon chain （XC_n，n=6, 8, 10, n is number of carbons） and one kind of surfactant withbranched carbon chains （IXC₈） respectively. The surface activity and thermodynamicproperties of micellization of the X-type alkyl sulfonate Gemini surfactants were comparedwith sodium dodecylsulfate by means of surface tension. The properties of XC_n are superiorto those of SDS such as theγCMCand CMC of XC₁0are 26.3 mN/m and 0.2 mmol/Lrespectively. The adsorption isotherms for XC_n were established by fitting the pre-CMCsurface tension data with a quadratic function. The ability of reducing of the surface tensionof IXC₈ is better, however, its ability of micellization is worse,γCMC= 26.8 mN/m, CMC =4.89 mmol/L. Thermodynamic parameters of micellization （ΔG_m^οΔH_m^ο-TΔS_m^ο） derived fromelectrical conductivity indicate that the micellization of XC_n is entropy-driven.The wetting ability and emulsification stability of these Gemini surfactants is excellent,but the lime soap dispersing power is worse apart from XC₁0. Moreover, the Geminisurfactant can be used in the low temperature through the determination of Krafft points.