Zheng Ou, Zhao Jian-Xi, Chen Rui-Ting, Fu Xian-Ming
Department of Applied Chemistry, College of Chemistry and Chemical Engineering, Fuzhou University, Fuzhou 350002, People's Republic of China.
J Colloid Interface Sci. 2006 Aug 1;300(1):310-3. doi: 10.1016/j.jcis.2006.03.061. Epub 2006 Mar 30.
The critical reverse micelle concentrations of C(12)-s-C(12).2Br (s=2,3,4,5,6,8,12) in n-heptane/n-hexanol solutions, cmc(I)s, have been determined by absorption spectrum method using iodine as probe. The values of cmc(I)s are smaller than those of the critical micelle concentrations (cmc(aq)s) in aqueous solution and reach a maximum at s=4, which is similar to the variation of cmc(aq) with s. The variation of cmc(I) with s is attributed to the alteration in the spacer chain conformation, i.e. when the spacer is short enough, it may adopt stretch configuration and when the spacer is long, it tends to bend towards the continuous oil phase to achieve a more densely packing of the quaternary ammonium heads on the surface of the core.
通过以碘为探针的吸收光谱法测定了C(12)-s-C(12).2Br（s = 2、3、4、5、6、8、12）在正庚烷/正己醇溶液中的临界反胶束浓度cmc(I)s。cmc(I)s的值小于其在水溶液中的临界胶束浓度（cmc(aq)s），且在s = 4时达到最大值，这与cmc(aq)随s的变化情况相似。cmc(I)随s的变化归因于间隔链构象的改变，即当间隔足够短时，它可能采取伸展构型；而当间隔长时，它倾向于向连续油相弯曲，以使季铵头在核表面更紧密地堆积。
