The Application Of Molecular Simulation In The Calculation Of Interfacial Interaction

Interactions at interface play very important roles both in chemical research and in practical applications, however estimation of interactions between all kinds of molecules is so complex that traditional experimental methods sometimes can not treat them well, especially; such kinds of methods can not give detail information at atomic scale. Meanwhile, the developments of computer and molecular simulation arithmetic make it possible to apply simulation technology to investigate interactions between different molecules at interface. In this study, two interfacial models, double layers model and random molecules cluster model, were applied to investigate interfacial interactions by using Materials Studio software package. The foundemental principle of these two models and related parameters were also discussed in detail.Two applications of these two interaction models, calculations of cyclohexanone formaldehyde resins (CFR's)-related molecules interactions and calcite-inhibitors interactions, were presented in this study.Random molecules cluster model was applied to study the interactions of CFR .modified CFR's (acetylated CFR and complete oxime of CFR) with a variety of solvent molecules by the mean of Monte Carlo approach; the free energies of solution were estimated, which indicated results being consistent with the experimental fact. Independent cohesive energy densities (CED's) and solubility parameters of CFR and modified CFR's were computed by molecular dynamics (MD) simulation. Miscibility of CFR and modified CFR's with a dimmer acid-based polyamide (D1007E) was estimated from the CED's. In addition, the interactions between coating layers (pure D1007E, D1007E with CFR, D1007E with acetylated CFR and D1007E with complete oxime of CFR) and a polystyrene substrate layer were investigated using double layers model, in an effort to identify the effect of CFR and modified CFR's in plastic printing application.Before calcite-inhibitors interactions were studied, Gibbs-Wulff theory was firstly introduced to calculate the growth morphology of CaCO3 without inhibitors. The simulated morphology agreed well with the SEM photograph. Then double layers model was applied to investigate the interactions between calcite and polymer inhibitors, and two kinds of inhibitors, maleic anhydride (MA) class and acrylic acid...