Effect of L-tyrosine on the micellar characteristics of various surfactants: a comparative study of the amino acid–surfactant interactions

In the present study, the aggregation process of three surfactants i.e., sodium dodecyl sulfate (SDS), Triton X-100 (TX-100), and cetyltrimethylammonium bromide (CTAB) with and without L-tyrosine (L-Tyr) has been investigated using viscosity, fluorescence, surface tension, UV–vis spectroscopy, dynamic light scattering (DLS), and FTIR methods at a temperature of 298 K. Different physio-chemical parameters, such as, critical micelles concentration (CMC), Γ_max, γ_CMC, π_CMC, pC₂₀ and A_min are computed and discussed thoroughly. Using a surface tensiometer, the surface characteristics and interfacial parameters of the surfactant systems in presence and absence of the L-Tyr amino acid (AA) are investigated. Measurements of the CMC using stalagmometric, fluorescence, and UV–visible spectrophotometry reveal the same pattern with differences in the following order: SDS > TX-100 > CTAB. Relative viscosity-based rheological behavior was calculated for three surfactant-L-Tyr systems. FTIR spectral analysis was done to reveal the micellization behavior of CTAB, SDS, TX-100, and L-Tyr systems. The FTIR data showed that the CTAB-L-Tyr and SDS- L-Tyr systems have significantly influenced the stretching frequency as compared to the TX-100-L-Tyr system. Pure surfactants average radius has demonstrated a bimodal distribution were observed and adding on 0.02 M of L-Tyr following the size shift, a polymodal distribution was observed in all surfactant systems. The effect of AA additions on the colloidal size and stability of surfactant aggregates was also examined. The aggregation process of anionic sodium dodecyl sulfate (SDS), nonionic Triton X-100 (TX-100), and cationic cetyltrimethylammonium bromide (CTAB) surfactants with and without L-tyrosine (L-Tyr) have investigated using viscosity, fluorescence, surface tension, UV–vis spectroscopy, dynamic light scattering (DLS), and FTIR methods, along with its detailed interfacial properties at a temperature of 298 K.