The Synthesis Of Carboxylate Gemini Surfactant And Their Physic-chemical Properties

Gemini surfactant, as a good performance of the new surfactant, has been much attention of domestic and foreign scholars. It has a hydrophilic group and a lipophilic group than a traditional surfactant. In this paper, a series of carboxylate type gemini surfactants TDDS-n(n=8,10,12 ) were synthesized. Its surface properties and micellar thermodynamic properties in aqueous solution were studied. The main results were as follows:Diethylenetriamine?sodium chloroacetate?acyl chloride were being used as raw materials, three kinds of carboxylate Gemini surfactants were designed and synthesized. And the effects of reaction time, reaction temperature and molar ratio of reactants were investigated. The stuucture of the final products were characterized and confirmed by FT-IR?1H-NMR.By using the Wilhelmy method,surface tension of aqueous solutions was determined at 25?. And calculated the ?max?Amin and pC20 Compared with the traditional surfactants, the carboxylate-type gemini surfactants synthesized in this paper had excellent surface activity.The cmc of TDDS-8 TDDS-10 and TDDS-12 respectively are 1.93mmol/L?0.39 mmol/L and 0.17 mmol/L; The ?cmc of TDDS-8 TDDS-10 and TDDS-12 respectively are 31.1 OmN/m?28.40 mN/m and 24.82 mN/m. The surface tension different temperatures was determined.The results showed that the micellization of the surfactants in the aqueous solution was a spontaneous process, it follows the entropy driving mechanism, the micellization capacity increased firstly and then decreased with the increase of temperature, and the enthalpy and entropy compensation on the series of carboxylate-type Gemini surfactants TDDS-8, TDDS-10 and TDDS-12 phenomenon existed in the micellization process.The bubble properties of the TDDS-n were determined by oscillation method. With the increasing of the concentration, foaming performance and foam stability were enhanced. But The foam stability decreased with the increase of temperature.The emulsification properties of surfactants in organic hexane, liquid paraffin and kerosene were determined by water splitting method. The emulsification property of surfactant in liquid paraffin was the best, followed by kerosene. The emulsified particle size distribution of the aqueous solution of the surfactant and the crude oil emulsion was measured by a biological microscope. The results showed that, they had good emulsification ability and the particle size of the emulsion is below 1?m.The solubilization ability of TDDS-n was determined by spectrophotometry. The solubilization capacities of TDDS-8, TDDS-10 and TDDS-12 to n-hexane were 240 mL/mol,320 mL/mol and 320 mL/mol, respectively. The compatibility was also studied. The compatibility between TDDS-n and the conventional anionic surfactant SDBS?the nonionic surfactant OP-10 were all excellent.