A Molecular Dynamics Study of Polyethylene

We have performed molecular dynamics simulation to demonstrate the conformational changes of a linear homopolymer chain, in the presence of solvent molecules. We examine the folding and unfolding of a single chain of polyethylene using implicit and explicit solvent models. In the implicit model, the solvent effect is incorporated by means of the truncated Lennard-Jones potential. The explicit solvent model was simulated by immersing the polymer chain in four different solvents. In addition to the random initial configuration, we have also probed the impact of a collapsed initial configuration to understand the physics involved in unfolding of a collapsed structure. These findings will have great significance in understanding the release of drug molecules loaded in polymers which can act as drug delivery vehicles. The structural changes are quantified by estimating the radius of gyration which gives a statistical measure of the size of the polymer chain. In the end, we establish a protocol to relate implicit and explicit solvent models