Influence of anionic surfactants on coacervation with cationic guar gum for hair care applications

To assess the impact of anionic surfactants on the formation of coacervates with cationic guar gum and their subsequent effects on hair care.

Coacervates were prepared using ionic precipitation techniques involving four anionic surfactants: sodium lauryl sulfate (SLS), sodium lauroyl sarcosinate (SNL), sodium lauryl sulfoacetate (SLSA), sodium cocoyl isethionate (SCI) and cationic guar gum. Viscosity, spreadability and stickiness sensory analysis were conducted with a panel of volunteers. The coacervates were freeze-dried, and their physicochemical properties were analysed using Raman and Fourier transform infrared spectroscopy, scanning electron microscopy and thermogravimetric analysis.

Coacervate formation and stability were dependent on the CGG-to-surfactant ratio, with 0.5% CGG/0.5% surfactant producing the most stable, uniform structures. Spectroscopic analyses confirmed stronger electrostatic and hydrogen bonding interactions at higher CGG concentrations, facilitating greater polymer-surfactant integration. Thermal analysis showed that balanced CGG/surfactant ratios enhanced coacervate stability, while excess surfactant led to lower thermal resistance and weaker deposition. SEM images revealed superior adhesion and homogeneous coverage on damaged hair fibres at 0.5% CGG/0.5% surfactant, suggesting better conditioning effects compared to lower polymer content.

The findings emphasize that coacervate stability, deposition efficiency and adhesion to hair fibres are optimized when CGG and surfactants are present in balanced ratios. The 0.5% CGG/0.5% surfactant formulation consistently exhibited superior stability, coverage and interaction with damaged hair, reinforcing its potential as an effective conditioning and protective system. These insights provide a foundation for improving coacervate-based hair care formulations, ensuring enhanced performance and long-term benefits.