Department of Chemistry, Faculty of Sciences and Letters, Trakya University, 22030 Edirne, Turkey.
Spectrochim Acta A Mol Biomol Spectrosc. 2010 Feb;75(2):671-7. doi: 10.1016/j.saa.2009.11.038. Epub 2009 Dec 3.
This study investigates the effects of various cationic surfactants on the cloud point (CP) of the nonionic surfactant Triton X-100 (TX-100) in aqueous solutions. Instead of visual observation, a spectrophotometer was used for measurement of the cloud point temperatures. The values of CPs for Triton X-100 can be measured directly because TX-100 has an average number of oxyethylene units per molecule of p approximately 9.5 and a CP=66.0 degrees C. Quaternary ammonium dimeric surfactants (m-s-m, m=10, 12, and 16, and s=2, 6, and 10) were synthesized and used. The melting temperature T(M) and the Krafft temperature T(K) were measured for 1 wt% aqueous solutions of these synthesized surfactants. The melting temperature of the solid gemini surfactants increased with the carbon number of the alkyl chain. The results showed that additions of the gemini surfactants (which are infinitely miscible with water) to Triton X-100 increased the cloud point of the TX-100 solutions. All salts tested in these studies had a large effect on the CPs of nonionic surfactants due to their effect on water structure and their hydrophilicity. The effect of the alkyl chain length of the gemini surfactant on the CP of Triton X-100 is therefore more important than the spacer chain length.
本研究考察了各种阳离子表面活性剂对非离子表面活性剂 Triton X-100（TX-100）水溶液浊点（CP）的影响。与目视观察不同，本研究使用分光光度计测量浊点温度。Triton X-100 的 CP 值可以直接测量，因为 TX-100 每个分子的平均乙氧基单元数 p 约为 9.5，CP=66.0°C。合成并使用了季铵二聚表面活性剂（m-s-m，m=10、12 和 16，s=2、6 和 10）。测量了这些合成表面活性剂 1wt%水溶液的熔点 T(M)和克拉夫特点 T(K)。固体双子表面活性剂的熔点随烷基链碳数的增加而升高。结果表明，双子表面活性剂（与水无限混溶）的添加会增加 TX-100 溶液的浊点。由于这些盐对水结构和亲水性的影响，所有在这些研究中测试的盐都对非离子表面活性剂的 CP 有很大影响。因此，双子表面活性剂的烷基链长度对 Triton X-100 的 CP 的影响比间隔链长度更重要。
