Geppert-Rybczyńska Monika, Mrozek-Wilczkiewicz Anna, Rawicka Patrycja, Bartczak Piotr
Institute of Chemistry, University of Silesia, Szkolna 9, 40-006 Katowice, Poland.
August Chełkowski Institute of Physics, University of Silesia, 75 Pułku Piechoty 1, 41-500 Chorzów, Poland.
Molecules. 2024 Apr 18;29(8):1844. doi: 10.3390/molecules29081844.
In this study, a series of four surface-active compounds--alkyl betaine ethyl ester chlorides, CBetCCl-were synthesized and characterized in aqueous solutions. As with other alkyl betaines, these amphiphiles can be practically used, for example, as co-surfactants and/or solubility enhancers acting according to hydrotropic or micellar mechanisms, depending on the alkyl chain length in the amine. We focused on the representatives of the medium alkyl chain length (C-C) to find the dependence between the alkyl chain length in -alkyl betaine ethyl ester chlorides and the surface, volumetric, acoustic, and viscometric properties of their solutions. Ethyl esters, the derivatives of amino acids, were chosen to increase functionality and take advantage of possible hydrolysis in solutions at higher pH, which is also a key parameter in biodegradability. The micellization parameters were calculated based on the physicochemical characteristics. We focused our interest on the ester with a dodecyl substituent since we can compare and discuss its properties with some other C representatives that are available in literature. Surprisingly, its micellization characteristic is almost temperature-independent in the investigated temperature range, = (15-45) °C. Particularly interesting are the results of dynamic light scattering (DLS), which show that the changes in physicochemical parameters of the C homolog around the CMC are caused by the two types of micelles of different sizes present in solutions.
在本研究中，合成了一系列四种表面活性化合物——烷基甜菜碱乙酯氯化物（CBetCCl），并在水溶液中对其进行了表征。与其他烷基甜菜碱一样，这些两亲物可实际应用，例如，根据胺中烷基链长度，作为辅助表面活性剂和/或根据水溶助长或胶束机制起作用的增溶剂。我们聚焦于中等烷基链长度（C-C）的代表物，以发现烷基甜菜碱乙酯氯化物中的烷基链长度与其溶液的表面、体积、声学和粘度性质之间的关系。选择氨基酸衍生物乙酯以增加功能性，并利用在较高pH值溶液中可能发生的水解，这也是生物降解性的关键参数。基于物理化学特性计算了胶束化参数。我们将兴趣集中在具有十二烷基取代基的酯上，因为我们可以将其性质与文献中可用的其他一些C代表物进行比较和讨论。令人惊讶的是，在研究温度范围 = (15 - 45) °C内，其胶束化特性几乎与温度无关。特别有趣的是动态光散射（DLS）的结果，其表明在临界胶束浓度（CMC）附近，C同系物的物理化学参数变化是由溶液中存在的两种不同大小的胶束引起的。
