Effect of Macromolecular Architecture on Adhesion

The behavior of single linear chains on a substrate is a well-studied area of polymer science. Herein, one of the most essential issues is the interaction of the chains with the substrate, which determines both macromolecular conformations near the substrate and adhesive properties of polymer materials. However, very little is known about the effect of macromolecular architecture on adhesion. In particular, there was no assessment of the effect of chain branching on the adhesion force. On the other hand, an essential progress in macromolecular chemistry allows the synthesis of various macromolecular architectures, including star-, comb-like, etc., in a very precise way. They are widely used in numerous applications. In particular, synthetic peptides are currently an integral part of many systems for biomedical purposes including bioglues, for which the adhesion force is a fundamental property. In this study, we conducted force experiments on the desorption of star-like pentapeptide chains from a solid substrate using an atomistic model of computer simulations. The cases of a linear chain and four- and eight-armed stars were considered. We have shown that the presence of branching enhances the adsorption strength under a fixed mass of the macromolecules. The force needed for chain desorption was shown to be linearly dependent on the branching degree.