无机盐对辛基酚聚氧乙烯醚乙基磺酸钠临界胶束浓度的影响研究

Investigation of Influence of Inorganic Salt on the Critical Micelle Concentration of Sodium Octylphenol Polyoxyethylenated Ethylsulfonate

在(25±0.2)℃的实验温度下,通过用表面张力法确定了辛基酚聚氧乙烯醚(10)乙基磺酸钠(OPS)在无机盐氯化物(LiCl,NaCl,KCl,MgCl2,CaCl2,BaCl2,AlCl3,FeCl3和SmCl3)水溶液中的临界胶束浓度(cmc)值,根据cmc值的变化得出无机盐反离子对非离子-阴离子型表面活性剂OPS的cmc值影响规律.实验数据分析表明,虽然非离子-阴离子型表面活性剂OPS分子中增加了一个非离子氧乙烯单元的亲水性基团,但其cmc值和无机盐反离子浓度[M]之间具有与离子型表面活性剂相似的线性关系:lgcmc=-4.242-(0.2980-0.0102Z/r)lg[M]([M]<1mol/L),其中Z和r分别为反离子的价态和范德华原子半径的平均值.无机盐对OPS的cmc的影响具有离子型表面活性剂的性质,不具有非离子型或两性表面活性剂的性质.该关系式亦说明了水溶液中非离子-阴离子型表面活性剂OPS的cmc值与无机盐反离子的浓度、价态和范德华原子半径的平均值有关,反离子对胶束的结合度的大小取决于反离子的价态与范德华原子半径平均值的比值.最后就无机盐反离子对OPS的cmc影响机理进行了简要分析.

At （25±0.2） ℃,the cmc values of nonionic-anionic surfactant sodium octylphenol poly-oxyethylenated ethylsulfonate （OPS） in the aqueous solution in the presence of inorganic salt,LiCl,NaCl,KCl,MgCl2,CaCl2,BaCl2,AlCl3,FeCl3 and SmCl3,were measured by the method of surface tension. An influence on the cmc of nonionic-anionic surfactant OPS with inorganic salt counter ion was generalized from the variation of the cmc. It is indicated from the mathematic analysis of experimental data that although an additional hydrophilic group of nonionic oxyethylene unit was introduced in the molecular chain of nonionic-anionic surfactant OPS,the relationship between its cmc and the concentration of inorganic salt counter ion [M] is similar to that of ionic surfactant as the followed linear formula：lg cmc=-4.242-（0.2980-0.0102 Z/r）lg[M] （[M]1 mol/L）,where Z and r are the valence number and the average Van der Waals radius of atom of counter ion,respectively,then is characteristic of ionic surfactants and not of nonionic or amphoteric surfactants. It is obviously showed from the above formula that the cmc of nonionic-anionic surfactant OPS is related to the concentration,the valence number and the average Van der Waals radius of atom of counter ion,and the degree of binding to micelle of counter ion depends on the ratio of the valence number to the average Van der Waals radius of atom of counter ion. And the mechanism of the inorganic salt counter ion effect on the cmc of OPS is briefly analyzed.