Studies on SDLC (Sodium Dilauraminocystine) and SDMC (Sodium Dimyristaminocystine) Gemini Surfactants

Abstract

The present work reports the synthesis and evaluation of surface active properties of amino acid-based gemini surfactants, namely, sodium dilauraminocystine (SDLC) and sodium dimyristaminocystine (SDMC) derived from L-cystine and fatty acids. The effect of reaction variables like molar ratio of raw materials and temperature has been studied for the synthesis of these gemini surfactants. In preparation of these gemini surfactants, fatty acids (lauric/myristic) were reacted with thionyl chloride to obtain respective acid chlorides (lauroyl/myristoyl). These acid chlorides were further reacted with L-cystine at different reaction conditions to get amino acid based-gemini surfactants. The study revealed that 1:2.5 molar ratio of reactants, namely, L-cystine and lauroyl/ myristoyl chloride and 10-15 reaction temperature resulted in maximum yield of amino acid-based gemini surfactants (SDLC and SDMC). Surface active properties of synthesized gemini surfactants (SDLC and SDMC) were also compared with their corresponding monomeric units, namely, sodium lauroyl cysteine (SLC) and sodium myristoyl cysteine (SMC), respectively. The results demonstrated that gemini surfactants (SDLC and SDMC) had better surface active properties than their corresponding monomeric units. The structures of synthesized amino acid-based gemini surfactants were also confirmed by FTIR, 1 H NMR, 13 C NMR, and ESI-MS spectral data.

Colloidal Stabilization of Sodium Dilauraminocystine for Selective Nanoparticle–Nanoparticle Interactions: Their Screening and Extraction by Iron Oxide Magnetic Nanoparticles

“…In this study, we address this issue by taking an aqueous system comprising Au and Ag NPs stabilized by a series of Gemini surfactants of different functional groups, which can mimic amphipathic biological molecules to understand the NP–NP interactions. − Gemini surfactants are considered to be highly amphiphilic molecules, which demonstrate strong solid–liquid interfacial adsorption. , For this purpose, an amino acid-based Gemini surfactant (sodium dilauraminocystine (SDLC))-stabilized NP suspension is selected to study its interactions with other NPs stabilized with molecules of different functional groups to understand different modes of NP–NP interactions. Both titrands and titrants used in this work are Au and Ag NPs, i.e., when Au NP suspension acts as a titrand, then Ag NP suspension is a titrant and vice versa.…”