KLK Oleo, SDN BHD, Menara KLK, Mutiara Damansara, 47810 Petaling Jaya, Selangor, Malaysia.
Physical and Theoretical Chemistry Laboratory, Oxford University, South Parks Road, Oxford, UK.
J Colloid Interface Sci. 2018 Feb 15;512:231-238. doi: 10.1016/j.jcis.2017.10.064. Epub 2017 Oct 18.
The methyl ester sulfonates represent a promising group of anionic surfactants which have the potential for improved performance and biocompatibility in a range of applications. Their solution properties, in particular their tolerance to hard water, suggests that surface ordering may occur in the presence of multi-valent counterion. Understanding their adsorption properties in a range of different circumstances is key to the exploitation of their potential. Neutron reflectivity and surface tension have been used to characterise the adsorption at the air-aqueous solution interface of the anionic surfactant sodium tetradecanoic 2-sulfo 1-methyl ester, CMES, in the absence of electrolyte and in the presence of mono, di, and tri-valent counterions, Na, Ca, and Al. In particular the emphasis has been on exploring the tendency to form layered structures at the interface. In the absence of electrolyte and in the presence of NaCl and CaCl and AlCl at low concentrations monolayer adsorption is observed, and the addition of electrolyte results in enhanced adsorption. In the presence of NaCl and CaCl only monolayer adsorption is observed. However at higher AlCl concentrations surface multilayer formation is observed, in which the number of bilayers at the surface depends upon the surfactant and AlCl concentrations.
甲酯磺酸盐是一类很有前途的阴离子表面活性剂，它们在一系列应用中具有提高性能和生物相容性的潜力。它们的溶液性质，特别是对硬水的耐受性，表明在多价抗衡离子存在下可能会发生表面有序排列。了解它们在各种不同情况下的吸附性质是开发其潜力的关键。中子反射率和表面张力已被用于表征在不存在电解质以及存在单价、二价和三价抗衡离子（Na、Ca 和 Al）的情况下，十二烷酸 2-磺基 1-甲酯钠盐（CMES）在空气-水溶液界面处的吸附。特别强调的是探索在界面处形成层状结构的趋势。在不存在电解质以及存在 NaCl 和 CaCl 和 AlCl 的低浓度下观察到单层吸附，而电解质的加入导致吸附增强。在存在 NaCl 和 CaCl 的情况下，仅观察到单层吸附。然而，在更高的 AlCl 浓度下，观察到表面多层形成，其中表面的双层数量取决于表面活性剂和 AlCl 的浓度。
