十二烷基硫酸钠与非离子表面活性剂AEO9/6501复配体系表面活性及动态表面张力研究

Study on surface active and dynamic surface tension of K_(12) and AEO_9/6501 complex systems

将十二烷基硫酸钠(K_(12))分别与脂肪醇聚氧乙烯醚9(AEO_9)和椰子油脂肪酸二乙醇酰胺(6501)这两种非离子表面活性剂按不同质量比复配,研究所得表面活性剂复配体系的临界胶束浓度(cmc)、表面张力(γ)和动态表面张力(DST).结果表明:当K12-AEO9和K12-6501复配体系质量比分别为1∶1和3∶7时,cmc值最小,分别为0.14 mmol·L^(-1)和0.30 mmol·L^(-1)),此时体系协同效应最好;当K12-AEO9复配体系质量比为1∶1时,平衡时间t*最小(1.42 s),表面张力降低速率R1/2最大(14.47 m N·m^(-1)·s^(-1)),此时体系动态表面活性最好;当K12-6501复配体系质量比为3∶7时,R1/2最大(14.25 m N·m^(-1)·s^(-1)),此时体系更易于达到介平衡态,动态表面活性最好.其规律是:随表面活性剂浓度的增加,两种复配体系在水表面达到吸附平衡的时间减小,表面张力降低速率增加.

The critical micelle concentration（ cmc）,equilibrium surface tension（ γ） and dynamic surface tension（ DST） of K12-AEO9 and K12-6501 formulations were investigated. The best synergistic effect and minimal cmc could be observed that is cmc was 0. 14 mmol·L^（-1）and 0. 30 mmol·L^（-1）when the mass ratio was 1∶1for K12-AEO9 and 3∶7 for K12-6501. When the mass ration of K12 and AEO9was 1∶1,the balance time（ t＊）was minium（ 1. 42 s）,the surface tension reducing rate（ R1/2） reached maximum（ 14. 47 m N·m^（-1）·s^（-1））and the binary system showed the best dynamic surface activity. As for K12-6501,the best results were observed when the mass ratio was 3 ∶7. The maximum R1/2（ 14. 25 m N·m^（-1）·s^（-1）） was obtained and the system was more easy to reach the equilibrium system of medium. The obtained experimental data showed that the two kinds of mixture adsorption equilibrium time on the water surface decreased and tension reducing rate of R1/2increased with the increasing of the surfactant concentration.