Adsorption and Desorption of Polymers on Bioinspired Chemically Structured Substrates

Natural biological surfaces exhibit interesting properties due to their inhomogeneous chemical and physical structure at the micro- and nanoscale. In the case of hair or skin, this also influences how waterborne macromolecules ingredients will adsorb and form cosmetically performing deposits (i.e., shampoos, cleansers, etc.). Here, we study the adsorption of hydrophilic flexible homopolymers on heterogeneous, chemically patterned substrates that represent the surface of the hair by employing coarse-grained molecular dynamics simulations. We develop a method in which the experimental images of the substrate are used to obtain information about the surface properties. We investigate the polymer adsorption as a function of polymer chain length and polymer concentration spanning both dilute and semidilute regimes. Adsorbed structures are quantified in terms of trains, loops, and tails. We show that upon increasing polymer concentration, the length of tails and loops increases at the cost of monomers belonging to trains. Furthermore, using an effective description, we probe the stability of the resulting adsorbed structures under a linear shear flow. Our work is a first step toward developing models of complex macromolecules interacting with realistic biological surfaces, as needed for the development of more ecofriendly industrial products.

Automated summary

This study investigates the adsorption of hydrophilic flexible homopolymers on a substrate representing the surface of the hair using coarse-grained molecular dynamics simulations. The research examines the impact of polymer chain length and concentration on adsorbed structures, as well as the stability of these structures under a linear shear flow. The work aims to develop models of complex macromolecules interacting with realistic biological surfaces for the development of more ecofriendly industrial products.