【摘要】 本文研究了十二烷基硫酸钠（SDS）和辛基酚聚氧乙烯醚（C₈PhE₉）混合表面活性剂水溶液的电导行为,并用表面张力实验数据、非理想溶液理论对其电导行为进行了计算,得到与实验相一致的结果。实验和理论计算结果均表明,在SDS中添加高于其临界胶团浓度的非离子表面活性剂C₈PhE₉,会使混合溶液电导率增加,增加的幅度随C₈PhE₉浓度增大而增大;两种表面活性剂之间存在弱相互作用,混合胶团中较多的非离子表面活性剂降低了胶团对反离子的束缚度,相应地增加了溶液中的导电离子数,是电导率增加的主要原因,文章还讨论了电导与相互作用的相关性。更多还原

【Abstract】 The conductivity and surface tension of the mixed aqueous solution ofsodium lauryl sulfate （SDS） and n-octylphenol polyoxyethylene ether （C₂ PhE₉）have been investigated. The conductivity of mixed solutions is determined atconstant [C₅ PhE₉] and at constant [SDS], respectively. In either case,the conductivity increases as [C₈ PhE₉] increases. This is explained by thefollowing reasons: （1） As mixed micelles are formed, C₈ PhE₉ moleculesenter the micelles so that some SDS molecules which were previously inmicelles become monomer surfactant, and there are more conductive ions inthe solution. （2） Since the mole fraction of C₈ PhE₉ in the mixed micellesincreases as [C₈ PhE₉] increases, the degree of counterions binding to themicelles decreases. This contributes a lot to conductivity particularly athigh [C₈ PhE₉]. Thus, the total concentration C₁^K which determines the con-ductivity can be expressed by following equation: C₁^K= C₁^f+（C₁-C₁^f） （1-0.65x₁）where C₁^f is the monomer concentration for SDS, C₁ is the total concentra-tion for SDS, and x₁ is the mole fraction of SDS in mixed micelle. By applying the nonideal solution theory, C₁^f, x₁, and the interactionparameter of SDS and C₈ PhE₉ in the mixed micelle （β） can be calculated.Then we get the theoretical value of C₁^K. The trends of C₁^K are parrallel tothose of the conductive experimental observation.更多还原