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The dynamic and structural properties of the water molecules in 3-(1-piperazinyl)-1,2-propanediol-containing polyvinyl alcohol membranes were analyzed by molecular dynamics simulations. The resulting curve of the coordination number with diffusivity yielded important insights into the changes in the state of the water molecules with the water content, clarifying a key factor in determining the membrane performance for CO₂ separation.

Irrespective of the degree of polymerization, the molecular mobilities of the 2-hydroxyethyl methacrylate (HEMA) moieties are smaller than those of the 2-methoxyethyl acrylate (MEA) moieties. Preventing the polar functional groups of the foulants and materials from forming a hydrogen-bonding network is important to enhance the mobilities of the molecular chains of non-ionic polymeric materials. We speculate that enhancing the mobilities of the molecular chains is key to improving blood compatibility.

Suppression of protein adsorption on polymeric interfaces is one of the significant challenges in developing novel biomedical polymers. In this study, the computational design of an antifouling polymer repeat unit is conducted based on a simple approach, whereby the intermolecular affinities between a probe molecule and a polymer repeat unit are evaluated to generate free energy profiles using molecular dynamics simulations. The simplified method affords convenient and theoretical screening of highly antifouling polymer repeat units.

The folding behavior of a 2-dimethylaminoethyl methacrylate oligomer with alternately protonated side chains surrounded by water molecules was evaluated using molecular dynamics simulations in the temperature range of 280–360 K. Radial distribution functions (RDFs) around the geometric center of the oligomer were evaluated; they indicated that protonated amine groups surrounded the aggregating deprotonated amine groups in the globule state. The calculation of RDFs around the geometric center is a highly reliable strategy to evaluate the folding behavior of stimuli-responsive polymer gels during the coil-to-globule transition.

Microscopic behaviors of explicit water molecules on biocompatible zwitterionic self-assembled monolayer (SAM) surfaces were investigated by molecular dynamics simulations. The orientational distribution of water molecules near the surfaces was evaluated to analyze its structural properties. Consequently, water molecules on the zwitterionic SAMs are randomly oriented. In contrast, those near the surface of poly(vinyl alcohol) are highly oriented, resulting from the structured hydrogen bonding network. Microscopic properties of water molecules on the interfaces would have a key role in the suppression of protein adsorption for zwitterionic biomaterials.