Morphological study of cationic polymer-anionic surfactant complex precipitated in solution during the dilution...

Area of Science:

• Colloid and Surface Science
• Polymer Chemistry
• Materials Science

Background:

• Cationic polymers and anionic surfactants form complexes with applications in personal care products.
• Understanding the relationship between complex formation, morphology, and performance is crucial for product development.

Purpose of the Study:

• To investigate the phase diagrams and morphology of complexes formed by cationic cellulose (CC) and cationic dextran (CD) with anionic surfactant sodium poly(oxyethylene) lauryl ether sulfate (LES).
• To explore how modifying surfactant charge with amphoteric (LPB) or nonionic (C18EO25) surfactants influences complex aggregation and hair conditioning.
• To correlate complex morphology and rheological properties with the tactile feel of hair after rinsing.

Main Methods:

• Formation and characterization of complexes between CC/CD and LES, with/without LPB or C18EO25.
• Observation of complex morphologies (membranous, mesh-like) under varying charge densities.
• Evaluation of hair touch and rheological properties during the rinsing process in a model shampoo solution.

Main Results:

• CC complex aggregates transitioned from membranous to mesh-like forms with decreased charge, altering hair feel from sticky to smooth/velvety.
• CD complex aggregates maintained a membranous form and smooth touch regardless of charge modifications.
• Rheological properties correlated with the observed tactile changes on hair.

Conclusions:

• The charge density of both cationic polymers and surfactants significantly impacts the morphology and conditioning performance of CC-based complexes.
• Polymer structure (CC vs. CD) plays a role in complex stability and tactile properties.
• Tailoring charge interactions is key to achieving desirable conditioning effects in hair care formulations.