NaBr对杂双子表面活性剂C_mOhpNC_8水溶液吸附和聚集的影响

以表面张力和荧光探针技术研究了NaBr对杂双子表面活性剂CmOhpNC8(m:10,14,16)水溶液性质的影响。结果表明,NaBr强烈促进了CmOhpNC8在气/液界面上的吸附和在水相中的聚集,其中c20在cNaBr≥10mmol/L时降到极低的微摩尔/升数量级,显示了相当高的降低水表面张力效率。在NaBr促进下,水溶液中CmOhpNC8表现出强烈的预胶团化行为。这些均是对应的2种单头基单烷烃链表面活性剂简单1:1混合所无法实现的,显示了在头基处引入短联接链形成杂双子结构的表面活性优势以及对盐效应的敏感性。

Effects of NaBr on Adsorption and Aggregation of Heterogemini Surfactant C_mOhpNC_8 in Aqueous Solution

The effects of NaBr on the properties of heterogemini surfactant C_mOhpNC_8(m:10,14,16) in aqueous solution were investigated by means of surface tension and fluorescence probe techniques. The results show that NaBr strongly promoted the adsorption and the aggregation of C_mOhpNC_8 at the air/water interface in aqueous bulk solution. The c_(20) was reduced to extremely low order of magnitude of micromole per liter at c(NaBr)≥10 mmol/L,showing quite a high efficiency in surface tension reduction. Upon NaBr addition,C_mOhpNC_8 exhibited strong premicellization in aqueous bulk solution. So low c_(20) and evident premicellization could not be observed in the equal-mole mixture of the corresponding conventional surfactants,exhibiting the surface-active advantage as well as the salt-sensitivity of heterogemini-type surfactant,in which a short spacer was introduced to link the two different headgroups.