Modeling the adsorption of copolymers on heterogeneous surfaces and the stability of polymer coatings for cosmetic applications

IRENE ADROHER-BENÍTEZ; TATIANA I. MOROZOVA; NICOLÁS A. GARCÍA; JEAN-LOUIS BARRAT; GUSTAVO S. LUENGO; FABIEN LÉONFORTE

Chania, Creta

Conferencia; ECIS 2022; 2022

ECIS

Polymers play a main role in most cosmetic products. In the case of hair care, their cosmetic performance is determined by the way polymers adsorb in the hair surface, which is highly conditioned by the physico-chemical properties of its external structure. For some years now, cosmetic industry has been making a great effort to develop new sustainable products that have better performance and at the same time are truly respectful with the environment. However, despite the large amount of experimental work already done in this direction, it remains to be known which physical quantities play a determining role in polymer adsorption onto hair-like substrates, as well as in the stability of these polymeric coatings.With this aim, we have analyzed the behavior of polymers of cosmetic interest in realistic surfaces, modeled from actual experimental images of human hair. In particular, in the work presented here we have prepared coarse-grained models for two different families of polymers. First, we have modeled semi-flexible linear chains in which each bead corresponds to a monomer. With this model we aim to study the performance of simple molecules of natural origin. Second, we have created a branched stiff polymer model with 17 beads per monomer. This more complex system is intended to mimic some of the macromolecules currently used in the cosmetic industry. For these two models we have performed implicit-solvent Molecular Dynamics simulations to study the quantities involved in the polymer adsorption onto a heterogeneous surface. We have analyzed the structure of the resulting coating and compared the results for the two types of polymers. Then, we have used Brownian dynamics simulations to apply a linear shear flow on the adsorbed polymer layer. This way we have tested the stability of the coating and we have analyzed the dynamics of the polymer desorption.