Synthesis, surface and micellar properties of sodium N-oleoyl amino acids (original) (raw)
Related papers
The surface tension and fluorescence measurements have been carried out to study the interactions present between anionic surfactant, sodium dodecyl benzene sulfonate (SDBS) and cationic surfactant, dodecyltrimethylammonium bromide (DTAB), in aqueous solution, in presence and absence of additives (glutamine, histidine and methionine) at different composition and temperature. Critical micelle concentrations (CMCs) have been determined using surface tension measurement. In case of SDBS, the CMC value increases with rise in temperature while in case of DTAB, it shows a U-type behavior, meaning thereby, both hydrophobic and hydrophilic dehydration becomes prominent in case of DTAB while only hydrophilic dehydration plays decisive role for the micellization to take place in case of SDBS. From surface tension data, the surface excess concentration at air/water interface ( max), minimum area per surfactant molecule (Amin) and the surface pressure at CMC (CMC) have been evaluated. Thermodynamic parameters of transfer, adsorption and micellization have also been evaluated and discussed in detail. Fluorescence probe study has been carried out to outline the results stated above. The CMC values calculated using pyrene as a fluorescent probe at room temperature resembles well with the micellar values determined using surface tension measurement.
Chemistry, 2022
The micellar properties of the anionic surfactant, sodium dodecyl sulfate (SDS) are modified by the biologically active amino acids. Amino acids (AAs) have experienced a variety of interactions and are proposed to influence SDS micelles due to their nominated hydrophobic interactions. The present study determines the critical micellar concentration (CMC) of SDS in aqueous solutions as well as in amino aqueous solutions. Three amino acids (glutamic acid, histidine, and tryptophan) are considered here. The conductometric measurements were carried out using a wide range of SDS concentrations at different temperatures. Surface tension experiments have also been applied to estimate many surface parameters including surface excess concentration (Γmax), surface occupied area per surfactant molecule (Amin), surface tension at CMC (γcmc), surface pressure at CMC (Πcmc) and Gibbs free energy of adsorption (∆Gads°), enthalpy ∆Hm° and the critical packing parameter (CPP). Interestingly, CMC val...