University of Vienna, Sensengasse 8, 1090, Vienna, Austria.
Soft Matter. 2019 Jan 2;15(2):175-189. doi: 10.1039/c8sm01850b.
The structure of a thin magnetoactive elastomeric (MAE) film adsorbed on a solid substrate is studied by molecular dynamics simulations. Within the adopted coarse-grained approach, a MAE film consists of magnetic particles modeled as soft-core spheres, carrying point dipoles, connected by elastic springs representing a polymer matrix. MAE films containing 20, 25 and 30 vol% of randomly distributed magnetic particles are simulated. Once a magnetic field is applied, the competition between dipolar, elastic and Zeeman forces leads to the restructuring of the layer. The distribution of the magnetic particles as well as elastic strains within the MAE films are calculated for various magnetic fields applied perpendicular to the film surface. It is shown that the surface roughness increases strongly with growing magnetic field. For a given magnetic field, the roughness is larger for the softer polymeric matrix and exhibits a nonmonotonic dependence on the magnetic particle concentration. The obtained results provide a better understanding of the MAE surface structuring as well as possible guidelines for fabrication of MAE films with a tunable surface topology.
通过分子动力学模拟研究了吸附在固体基底上的薄磁敏弹性体（MAE）薄膜的结构。在所采用的粗粒化方法中，MAE 薄膜由磁性粒子组成，这些粒子建模为带有点偶极子的软核球体，并通过代表聚合物基质的弹性弹簧连接。模拟了含有 20%、25%和 30%体积分数的随机分布磁性粒子的 MAE 薄膜。一旦施加磁场，偶极子、弹性和塞曼力之间的竞争导致层的重构。计算了垂直于薄膜表面施加的各种磁场下 MAE 薄膜内磁性粒子的分布以及弹性应变。结果表明，随着磁场的增大，表面粗糙度强烈增加。对于给定的磁场，较软的聚合物基质的粗糙度更大，并且表现出对磁性粒子浓度的非单调依赖性。所得到的结果提供了对 MAE 表面结构化的更好理解，以及对具有可调表面拓扑的 MAE 薄膜制造的可能指导。
