(181l) Solvent Responsive Polymer Brushes for Selective Separations – A Molecular Simulation Study

Biology offers several examples of extreme specificity and selectivity (such as ion- and trans-membrane channels) that if mimicked in engineering processes can be translated to high-throughput separation technologies. Such large-scale assemblies are not just passive sieves; their separation specificity is a result of built-in molecular functionality that dynamically responds to the changes in the environment of the pore. We utilize molecular simulations and a minimal model of a solvent-responsive functional sieve to investigate the relationship between the hierarchical internal structure of the sieve and mass transport across the sieve. The model sieve is made up of a polymer brush consisting of end-grafted polymer chains that respond to changes in solvent quality. We further assess the effects of both intra-molecular interactions of a constituent polymer chain and the inter-molecular interactions between the constituent chains of the brush, on the dynamics and the organization of the brush as functions of changes in solvent quality. Our simulations provide us insight could guide the development of artificial ultra-specific separation processes.