Study on the distribution of binary mixed counterions in surfactant adsorbed films by total reflection XAFS measurements
Study on the distribution of binary mixed counterions in surfactant adsorbed films by total reflection XAFS measurements
复制标题
全反射XAFS测量研究表面活性剂吸附膜中二元混合抗衡离子的分布
DOI：
10.1016/j.jcis.2012.08.044
复制
发表时间：
2012
影响因子：
9.9
通讯作者：
et al
中科院分区：
文献类型：
--
作者：
Yosuke Imai;et al
用全反射X射线吸收精细结构(TRXAFS)技术研究了十二烷基三甲基溴化铵(DTAB)和十二烷基三甲基四氟硼酸铵(DTABF4)组成的表面活性剂水溶液表面的吸附膜。所获得的XAFS光谱由完全水合的溴离子(FREE-BR)和部分脱水的溴离子吸附到表面活性离子的亲水基团(BIND-BR)对应的两个特定光谱的线性组合表示。确定了游离型和结合型溴离子的比例与表面张力和表面活性剂的表面组成的函数关系。同时考虑到我们以前对DTAB-十二烷基三甲基氯化铵(DTAC)和1-己基-3-甲基咪唑溴化物(HMIMBR)-1-己基-3-甲基咪唑四氟硼酸盐(HMIMBF4)混合体系的研究结果，推导了具有相同表面活性离子但不同反离子的表面活性剂混合物的反离子分布与反离子在溶液表面的混溶程度之间的关系。
The total reflection X-ray absorption fine structure (TR-XAFS) technique was applied to adsorbed films at the surface of aqueous solutions of surfactant mixtures composed of dodecyltrimethylammonium bromide (DTAB) and dodecyltrimethylammonium tetrafluoroborate (DTABF4). The obtained XAFS spectra were expressed as linear combinations of two specific spectra corresponding to fully hydrated bromide ions (free-Br) and partially dehydrated bromide ions adsorbed to the hydrophilic groups of surfactant ions (bound-Br) at the surface. The ratio of free- and bound-Br ions was determined as a function of surface tension and surface composition of the surfactants. Taking also the results in our previous studies on the DTAB – dodecyltrimethylammonium chloride (DTAC) and 1-hexyl-3-methylimidazolium bromide (HMIMBr) – 1-hexyl-3-methylimidazolium tetrafluoroborate (HMIMBF4) mixed systems into consideration, the relation between counterion distribution and miscibility of counterions at the solution surface was deduced for the surfactant mixtures having common surfactant ions but different counterions.