Laboratory of Physical Chemistry, Department of Chemistry, Aristotle University of Thessaloniki, 54124, Thessaloniki, Greece.
J Colloid Interface Sci. 2011 Feb 1;354(1):275-81. doi: 10.1016/j.jcis.2010.09.079. Epub 2010 Oct 8.
The adsorption of cetyltrimethylammonium bromide (CTAB) and cetyldimethylbenzylammonium chloride (CDBACl) on a hanging mercury electrode is studied using adsorptive transfer stripping voltammetry. The surfactants are adsorbed on mercury and are then transferred in KBr or KCl under various conditions, including temperatures from 1 to 40°C, open or closed circuits with different initial potentials, and repeated scans, etc. The results are compared with previously published results on the adsorption of CTAB or CDBACl on mercury, where condensed films were formed and are quite different than those obtained by adsorptive stripping voltammetry. In this case, an absence of condensed film is observed for CTAB. A condensed film with low capacitance value is formed in the case of CDBACl after transfer at low temperatures, or after repeated scans, resulting in reorientation of the molecules to more compact states. Capacity time curves at the potentials where the film is formed show in a few cases a nucleation and growth mechanism, with induction time and studied by the Avrami formulation, while an observed increase of the capacitance with time is attributed to the formation of hemimicelles. The results also indicate the importance of interactions between the hydrophobic chains.
十六烷基三甲基溴化铵（CTAB）和十六烷基二甲基苄基氯化铵（CDBACl）在悬汞电极上的吸附作用采用吸附传递溶出伏安法进行研究。在汞上吸附表面活性剂，然后在 KBr 或 KCl 中在不同条件下进行转移，包括 1 至 40°C 的温度、具有不同初始电势的开路或闭路以及重复扫描等。结果与先前发表的关于 CTAB 或 CDBACl 在汞上的吸附的结果进行了比较，其中形成了凝聚膜，与通过吸附溶出伏安法获得的结果有很大不同。在这种情况下，观察到 CTAB 不存在凝聚膜。在低温下或经过多次扫描后，CDBACl 在转移后形成具有低电容值的凝聚膜，导致分子重新定向到更紧凑的状态。在形成膜的电势下的电容时间曲线在少数情况下显示出成核和生长机制，通过阿弗拉米公式研究诱导时间，而观察到的电容随时间增加归因于形成半胶束。结果还表明疏水链之间相互作用的重要性。
