表面活性剂与金属离子的相互作用

INTERACTIONS OF SURFACTANTS WITH METALLIC CATIONS

烷基硫酸盐(CnS)的抗盐能力很差,在其中引进氧乙烯基(Eo)以后,形成的烷基聚氧乙烯基醚硫酸盐(CnEnS)的抗盐能力明显增强。把CnEnS加到CnS中,形成混合表面活性剂的低温抗盐能力也将明显改善。Doscher、Schott等人认为,CnEnS中的Eo与高价金属阳离子形成了一种“复合物”,这使得CnEnS具有很强的抗盐能力。Chiu则没有发现这种“复合物”。显然,了解CnEmS的抗盐机理,对于该类表面活性剂的理论研究和实际应用,都有重要的意义。

The concentration (c)-voltage (V) relations of K^+ and Ca^(2+) in surfactant solutions have been measured by ionic selective electrodes. The results show that it is very easy to form ion-pair, for alkyl sulfate(RS)and metallic cations which is the reason why the eletrolyte tolerance of RS is very low; The situation between the polyoxyethylene group in alkylpolyox yethylene ether sulfate salts (RE_nS) and multivalent metallic cations (Mn^(n+)) may be considered as the interaction performed by complexation, which prevents RE_nS and M^(n+) to form ion-pair, and this is one of the reasons why RE_nS have a higher eletrolyte tolerance.