Cationic and nonionic surfactant adsorption on thiol surfaces with controlled wettability
Cationic and nonionic surfactant adsorption on thiol surfaces with controlled wettability
复制标题
DOI：
10.1021/la011774b
复制
发表时间：
2002-09-03
期刊：
影响因子：
3.9
通讯作者：
Stålgren, JJR
中科院分区：
文献类型：
--
作者：
Boschkova, K;Stålgren, JJR
我们已经证明，硫醇化表面在使用石英晶体微天平耗散的吸附测量中作为模型基材效果非常好。由疏水性SH-C-16和亲水性SH-C16OH、封端硫醇的混合物制备功能化自组装单层，这使得表面的界面能能够以系统的方式改变。制备的硫醇表面用作吸附阳离子（DTAB，十二烷基三甲基溴化铵）和非离子（C12EO8，八（环氧乙烷）单（正十二烷基醚））表面活性剂的底物。当表面甲基分数增加时，DTAB 和 C12EO8 的吸附量增加。特别是，在 SH-C16 基团表面覆盖率为 25-50% 时，存在从胶束表面活性剂层到表面活性剂单层的转变。此外，还讨论了带电表面活性剂吸附表面活性剂层中抗衡离子对石英晶体微天平确定的质量和粘弹性响应的贡献。
We have shown that thiolated surfaces work very well as model substrates in adsorption measurements using the quartz crystal microbalance-dissipation. Functionalized self-assembled monolayers were prepared from mixtures of hydrophobically, SH-C-16, and hydrophilically, SH-C16OH, terminated thiols, which allowed the interfacial energy of the surfaces to be changed in a systematic way. The prepared thiol surfaces were used as substrates for adsorption of a cationic (DTAB, dodecyltrimethylammonium bromide) and a nonionic (C12EO8, octa(ethylene oxide) mono(n-dodecyl ether)) surfactant. When the fraction of methyl groups at the surfaces was increased, the adsorption for both DTAB and C12EO8 was increased. In particular, there is a transition from a micellar surfactant layer to a surfactant monolayer at 25-50% surface coverage of SH-C16 groups. In addition, the role of the counterion in the adsorbed surfactant layer for the charged surfactant is discussed in terms of contribution to the mass and viscoelastic response determined by the quartz crystal microbalance.