Thesis subject

Effects of chain architecture on the co-assembly of polymers and surfactants in bulk and at interfaces

Cosmetic formulations for hair are mixtures of cationic polyelectrolytes and anionic surfactants. Adsorption of either the pure polyelectrolyte (PE) or the polyelectrolyte-surfactant associative mixture on the hydrophobic keratin surface restores or improves the tribological properties of hair. Modelling of such multicomponent mixtures is a challenging topic. We investigate using the self-consistent field (SCF) theory the adsorption characteristics of binary mixtures of polymers (cationic or zwitterionic polyelectrolytes) and surfactants (anionic) from dilute solutions.

The key challenge is to understand how these mixtures and specifically these polymers adsorb onto pH tuneable electrified interfaces. A critical step in the analysis is to grasp, on a molecular level, how the self-assembly of the surfactant is affected by the oppositely charged polyelectrolytes in the bulk.

Our strategy is to study the two problems one after the other, that is, adsorption is studied after the bulk analysis. The investigations will be targeted to be relevant for shampoo applications.