Effect of End-Grafted Polymer Conformation on Protein Resistance

Monte Carlo simulation combined with an experimental method was used to investigate the effect of the conformational structure of polymer brushes on their protein resistance. The end-grafted polymers with two conformational structures, i.e., linear and looped, were considered. Protein adsorption behaviors on the surfaces grafted with either linear or looped polymers were investigated. Different chain lengths and grafting numbers of end-grafted polymers were employed in this simulation. The simulation results indicated that for long polymer brushes the conformational change from linear to looped generally improved their protein-resistant property for all of the grafting numbers investigated here, and a remarkable improvement in protein resistance can be achieved at a certain grafting number. Moreover, the simulations revealed that the smoothness of the surface and the formation of a dense impenetrable layer are the two significant characteristics of the looped polymer brush in resisting protein adsorption. Meanwhile, experiment results also showed that for a given chain length and grafting number the protein-resistant property of the looped polymer brush was superior to that of the surface grafted with linear polymers, which is quite consistent with the simulation results. These results further elucidated the difference in the protein resistant property between the linear and looped polymer brushes, which provided useful information for preparing excellent antifouling materials in future experiments.