二元表面活性剂混合体系表面活性及胶束形成热力学

摘要

通过平衡表面张力的测定,研究了聚氧乙烯（10）油基醚（Brij97）/硬脂酸蔗糖酯、聚氧乙烯（20）油基醚（AEO20）/硬脂酸蔗糖酯及Brij97/卵磷脂混合体系的表面活性及胶束形成的热力学性质（ΔGom、ΔHom、ΔSom）,并探讨了温度对各混合体系的影响.研究表明,三个混合体系均为非理想混合.对比分析得如下结果：（1）与AEO20相比,Brij97能显著提高硬脂酸蔗糖酯的表面活性.Brij97/硬脂酸蔗糖酯体系胶束形成及表面吸附能力均随Brij97的摩尔分数α1的增大而减小.（2）硬脂酸蔗糖酯、卵磷脂均不同程度的降低了Brij97的表面活性及形成胶束的能力.其中卵磷脂的影响更加明显,随卵磷脂摩尔分数α1的增大,CMC及ΔGom均大幅度增大.（3）在25℃-45℃范围内,温度升高,促进了各混合体系胶束的形成.%The surface properties and thermodynamic parameters of micellization for binary systems of oleylpolyoxyethylene（10）（Brij97）/sucrose stearate,oleylpolyoxyethylene（20）（AEO20）/sucrose stearate and Brij97/Lecithin were calculated from surface tension data.The effect of temperature on mixed systems which molar fraction is 0.5were discussed.The results reveal that the three investigated systems show non-ideality in the micelle formation.The three systems have been showed（1）Compared with AEO20,Brij97can enhance the surface properties of sucrose stearate obviously.the larger the mole fraction of Brij97,the decreasinger the CMC,γCMC and free energy（ΔGom）of micellization in Brij97/su-crose steatite mixed surfactants.（2）The surface properties and the capacity of forming micelle are de-creased by Lecithin and sucrose steatite,and the effect of Lecithin on Brij97is obvious.（3）in the range of 25℃to 45℃,the three mixed systems form micelle easily as the temperature increase.