CAJ | 학술논문

通过Monte Carlo模拟结合原始路径分析( PPA)的方法，阐述了缠结高分子薄膜的界面动力学与缠结程度的关系.研究发现，以吸附势能的临界值εwc≈-0.6 kB T附近为界，当墙壁-高分子作用势能从弱吸引到强排斥变化时，界面层中的链移动快于中心层，只有当墙壁的吸引作用增强到一定程度时，界面层中的链移动才会慢于中心层.界面动力学受到促进或阻碍可能与界面层和中心层的缠结程度直接相关：界面层的缠结程度保持在本体水平上基本不变；中心层的缠结程度在强吸引表面上低于界面层，而在弱吸引和排斥表面上高于界面层.此外，中心层和界面层中高分子链受限程度的变化对薄膜界面动力学行为的转变产生一定影响.对于薄膜中链密度分布情况随墙壁-高分子作用势能变化的分析为相关的物理化学机制提供了理论依据.
통과Monte Carlo모의결합원시로경분석( PPA)적방법，천술료전결고분자박막적계면동역학여전결정도적관계.연구발현，이흡부세능적림계치εwc≈-0.6 kB T부근위계，당장벽-고분자작용세능종약흡인도강배척변화시，계면층중적련이동쾌우중심층，지유당장벽적흡인작용증강도일정정도시，계면층중적련이동재회만우중심층.계면동역학수도촉진혹조애가능여계면층화중심층적전결정도직접상관：계면층적전결정도보지재본체수평상기본불변；중심층적전결정도재강흡인표면상저우계면층，이재약흡인화배척표면상고우계면층.차외，중심층화계면층중고분자련수한정도적변화대박막계면동역학행위적전변산생일정영향.대우박막중련밀도분포정황수장벽-고분자작용세능변화적분석위상관적물이화학궤제제공료이론의거.
We investigated the relationship between the interfacial dynamics and chain entanglement of polymer melts in confinement by means of the lattice Monte Carlo simulations using the bond-fluctuation model, combining the primitive path analysis. When the wall-polymer interaction varies from weakly attractive interaction to strongly repulsive interaction, chain mobility in the interfacial region is higher than that in the inner region. Only when the wall-polymer attraction is stronger than a critical adsorption strength will chain mobility in the interfacial region be lower than that in the inner region. The facilitation or retardation of interface dynamics may be directly related to the degree of entanglement in the interfacial and inner regions:the entanglement degree in the interfacial region retains the bulk level despite of the wall-polymer interaction;the entanglement degree in the inner region is lower than that in the interfacial region when the polymer film is confined between strongly attractive walls, but it is higher when the film is between weakly attractive or repul-sive walls. The variations of the confinement degree of polymer chains in both interfacial and inner regions also have an impact on the interface dynamics. Analysis on chain density distribution in the film as a function of the wall-polymer interaction provides a certain explanation for the related physical mechanisms.