A Molecular Dynamics Study on Polycaprolactone -Metal Oxide Interactions

Abstract In order to realize the macroscopic features of a number of chemically bonded multi-layer dielectric and composite materials, interactions of metal oxide surfaces, polymer surface atoms, and near-surface atoms are very beneficial. The simulation study of polymer-metal oxides interfaces is of great importance in investigating the adhesion and miscibility features of these systems that are inherently challenging to obtain experimentally or for which there is no experimental data, even if some low data exist, they are not reliable. Polycaprolactone (PCL) is biocompatible, biodegradable, non-toxic and hydrophobic polyester that has been used in tissue engineering, such as a bioactive implant. Hence, the molecular dynamics simulations of PCL are carried out to investigate its surface interaction with metal oxides as ZnO, CuO, Fe2O3, NiO and SiO2. The force field of COMPASS is applied to simulations in order to compute interfacial and solubility parameters. Molecular dynamics approach to investigate the interaction and adsorption manner of PCL with metal oxides. Whereas investigations are useful in exploring polymer composites. Much better adhesion is achieved by the calculations between the PCL oligomer and the metal oxides under investigation. The negative values of interaction energy have to be forecasted despite the presence of acid-base or hydrogen-bonding interactions.

摘要
为了揭示多种化学键合多层介电材料及复合材料的宏观特性，金属氧化物表面、聚合物表面原子与近表面原子之间的相互作用具有关键研究价值。针对聚合物-金属氧化物界面开展模拟研究，对于探究此类体系的黏附性与相容性特征具有重要意义——这类体系的实验表征往往存在固有难度，或缺乏相关实验数据；即便存在少量零散数据，其可靠性也较差。
聚己内酯（Polycaprolactone, PCL）是一种生物相容性优异、可生物降解、无毒且具有疏水性的聚酯材料，已被广泛应用于组织工程领域，例如用作生物活性植入物。因此，本研究通过分子动力学模拟，探究PCL与氧化锌（ZnO）、氧化铜（CuO）、三氧化二铁（Fe₂O₃）、氧化镍（NiO）以及二氧化硅（SiO₂）等金属氧化物的表面相互作用。
本研究采用COMPASS力场开展模拟计算，以获取界面参数与溶解度参数；本研究通过分子动力学方法探究PCL与金属氧化物的相互作用与吸附行为，此类研究对于聚合物复合材料的开发具有重要价值。计算结果表明，PCL低聚物与本研究考察的金属氧化物之间可实现更优异的黏附性能。尽管体系中存在酸碱相互作用与氢键相互作用，但模拟预测得到的相互作用能均为负值。