Investigation of the synergistic effect and the morphology of the binary compound systems with potassium N-lauroyl glycinate

Potassium N-lauroyl glycinate (PLG) is an amino acid surfactant widely used in detergents and has excellent chemical properties. In the present work, PLG was mixed in different molar ratios (α1) with the commonly used amphoteric surfactant lauryl amidopropyl betaine (LAB) or the non-ionic surfactant alkyl glycoside (APG). Subsequently, the surface tension, average hydrodynamic radius and number of micellar aggregates of the individual surfactants and the compound systems were measured using the hanging plate method, dynamic light scattering and fluorescence probe method, respectively, and the corresponding surface activity parameters were calculated. The results show that the binary PLG/LAB and PLG/APG systems exhibit non-ideal behaviour and that there was mutual attraction in the systems. The broad distribution of the micelle radius of the PLG/LAB compound system indicates that there are two types of micelles, namely spherical and rod-shaped in the systems. The distribution of the micelle radius of the PLG/APG compound system decreases to the minimum value at α 1 = 0.5. At α 1 = 0.7 and 0.9, double peaks and a broad distribution were also observed. The number of micelle aggregates in the PLG/LAB and PLG/APG compound systems is less than that of the individual surfactants at the respective mole fractions.

Study on the Synergism of Binary Surfactant Mixtures containing N-lauroyl-N-methyl Taurine Sodium

The surface tension of the two mixed systems had been investigated in 0.1 M NaCl solution at 298.15 K respectively, including the surface tension of the anionic surfactant N-lauroyl-N-methyl taurine sodium (SDMT) and of the cationic surfactant dodecyltrimethylammonium chloride (DTAC), and zwitterionic surfactant dodecyl betaine (BS-12). The chemical surface properties of the two mixed systems were studied and the regular solution theory was applied to the two mixed systems. The results showed that the binary surfactant mixtures of SDMT/DTAC and SDMT/BS-12 exhibited synergism in surface tension reduction effectiveness, surface tension reduction efficiency and the mixed micelle formation according to β values. It was also found that the results calculated by this theory agreed well with the experimental values.

Research of Binary Surfactant Mixtures Based on N-Lauroyl Sarcosinate

Surface properties of binary surfactant systems of N-lauroyl sarcosinate (LS) with fatty alcohol polyoxyethylene ether (AEO9), dodecyl trimethyl ammonium chloride (DTAC) and dodecyl dimethyl betaine (BS-12) have been investigated in aqueous NaCl (0.1 mol · L−1) solution at (298 ± 0.1) K, respectively. Synergistic parameters of the two components in both mixed micelles and mixed adsorption layers were obtained by calculations. Furthermore, we applied the regular solution theory on the mixed systems when synergism in mixed micelle formation, surface tension reduction efficiency and surface tension effectiveness was researched. The results show that there are synergistic effects in the mixed systems, the surface performances of the mixtures are significantly better than that of any single component in the mixed systems. The result coincides with the relevant theories of the ability of mixed micelle formation, surface tension reduction efficiency and surface tension reduction effectiveness.