Molecular-scale study on polymer chains behavior in the vicinity of nano-reinforcements has been drawn into focus by researchers due to its influence on macroscopic properties. Such a study by experimental means requires much time and expensive equipment, besides having instrumental and operator errors. This has stimulated theoretical research using computational means based on simulation methods such as molecular dynamics (MD). In current work, the aim is to simulate poly (2-ethyl-2-oxazoline), which is an aliphatic semiflexible polyester using MD, near graphene nanosheet. Graphene nanosheet was of square geometry with 20 nm dimension, while poly (2-ethyl-2-oxazoline) was simulated in three different chain lengths (number of monomers), 10, 20, 30. All simulations were carried out for 10 ns under three different temperatures, 300, 350, 400 K. Graphene nanosheets were studied in pure and functionalized forms, where functionalization was performed using hydroxyl and carboxyl groups. Energy diagrams variation against time revealed equilibration of the simulated systems. MD snapshots showed conformational change of polymer chain upon interacting with graphene nanosheets. Van der Waals interactions were found to be the predominant interactions. Polymer chain was adsorbed onto graphene as a result of interactions, where folded polymer chain adopted a flat arrangement parallel with graphene plane, so that the polymer chain end-to-end vector remained parallel with graphene plane. An increase in temperature led to an increase in polymer chain mobility and conformational order. Such an order is also enhanced for the system with functionalized graphene. Gyration radius was also found to increase when the polymer chain approached the graphene nanosheet. Mean-square-displacement of polymer chain decreased as the polymer chain became near to graphene. Keywords : poly (2-ethyl-2-oxazoline); molecular dynamics simulation; graphene nanosheet
