Binding affinity between small molecules in solvent and polymer film using molecular dynamics simulations

摘要

Quantifying the binding affinity of small molecules to a polymeric film is very important in understanding the adsorption phenomenon in food industry. Here we present a model based on molecular dynamics simulations in conjunction with the Metadynamics method to reconstruct the free energy barrier for desorption of small molecules from a polymer surface. We use this technique to find the binding affinity of five small binder molecules (C8, C9, C10, Eugenol and D-limonene) to a polymeric film in water solvent that is primarily due to the van der Waals, hydrogen bonding and electrostatic interactions. It is found that the small molecule binding is a spontaneous process, the binding affinity is affected by their molecular structure and polarity, the aldehydes (C8, C9, C10) have much higher affinity than the Eugenol and the D-limonene, the binding affinity increases with a rise in temperature, and the aldehydes show higher temperature sensitivity than the Eugenol and the D-limonene. These findings suggest the possibility of using the binding affinity, especially the binding free energy, to guide the design and selection of polymeric barrier materials. (C) 2017 Elsevier B.V. All rights reserved.