Effect of Macromolecular\nArchitecture on Adhesion

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