Design of dialkyl surfactants from nitrilotriacetic acid as head group

• Published in: RSC advances 2014, Vol.4 (14), p.6869-6877
• Main Authors: Trillo, Juan V., Meijide, Francisco, Tato, José Vázquez, Jover, Aida, Soto, Victor H., de Frutos, Santiago, Galantini, Luciano
• Format: Article
• Language: English
• Subjects: Agglomeration
• ISSN: 2046-2069; 2046-2069
• DOI: 10.1039/c3ra45543b

New double-chain surfactants can be designed in which nitrilotriacetic acid plays the role of glycerol in phospholipids. The synthetic methodology is applied to the synthesis of (2-(bis(2-dodecylamino)-2-oxoethyl)amino)acetic acid. This is a symmetric dimeric surfactant but the methodology allows the synthesis of asymmetric double-chain surfactants as well. The Krafft temperature is 16-18 degree C. The critical aggregation concentration of the new surfactant (4.76 10 super(-5) mol dm super(-3) in NaOH 0.01 M and 25 degree C; surface tension measurements) is two hundred times lower than that for sodium 2-dodecanamidoacetate, which can be considered its monoalkyl surfactant analog, indicating the enhanced surfactant properties resulting from the presence of two hydrophobic alkyl chains. The shape of the aggregates was investigated by transmission electron microscopy. At 40 degree C, the main structure present in solution corresponds to vesicles and, from the size distribution of their radii, values of (0.34 plus or minus 0.06)kTand 56.7 plus or minus 2.6 nm were obtained for the effective bending elasticity constant and the spontaneous radius of curvature of vesicles, respectively.