Carnitine alkyl ester bromides as novel biosourced ionic liquids, cationic hydrotropes and surfactants

作     者：Haeckl, Katharina Muhlbauer, Andrea Ontiveros, Jesus F. Marinkovic, Sinisa Estrine, Boris Kunz, Werner Nardello-Rataj, Veronique 

作者机构：Univ Artois Univ Lille Cent LilleUMR 8181 ENSCLUCCS Unite Catalyse & Chim SolideCNRS F-59000 Lille France ARD AgroInd Rech & Dev Route Bazancourt F-51110 Pomacle France Univ Regensburg Inst Phys & Theoret Chem Univ Str 31 D-93053 Regensburg Germany 

出 版 物：《JOURNAL OF COLLOID AND INTERFACE SCIENCE》 (胶体与界面科学杂志)

年 卷 期：2018年第511卷

页      面：165-173页

核心收录：

学科分类：081704[工学-应用化学] 07[理学] 070304[理学-物理化学(含∶化学物理)] 08[工学] 0817[工学-化学工程与技术] 0703[理学-化学] 

主　　题：Carnitine alkyl esters Cationic Ionic liquids Hydrotropes, surfactants 

摘      要：Hypothesis: In contrast to anionic and nonionic amphiphilic substances, bio-based cationic ones are very rare. Cationic amphiphiles are mostly based on quaternary ammonium, pyridinium or imidazolium groups that are either badly biodegradable or have toxic residues even after degradation. In the search for green alternatives to cationic hydrotropes and amphiphiles, natural L-carnitine could be a promising candidate for a cationic headgroup. Experiments: By esterification of carnitine in one step and with low cost, cationic molecules with alkyl chain length of n = 2-14 could be obtained. Their thermal properties, aggregation behaviour and cytotoxicity were determined. Hydrophobic compounds were solubilized in their aqueous solutions and the PIT slope method was applied to determine a relative hydrophilicity. Findings: It was found that some pure carnitine ester bromides were liquid at room temperature and thus can be classified as ionic liquids. They are highly water-soluble, and in aqueous solutions, they showed hydrotrope or surfactant behaviour depending on their alkyl chain length. Their high hydrotropic efficiency was demonstrated by solubilizing Disperse Red 13, while also biomolecules, like vanillin, could be dissolved in reasonable amounts. In all tests, they performed at least as good as the tested reference substances, while showing similar cytotoxicity towards human skin keratinocytes, thus demonstrating their potential as green functional amphiphilic molecules of positive charge. (C) 2017 Elsevier Inc. All rights reserved.