Chen Xinxiang, Qi Shuanhu, Zhang Xinghua, Yan Dadong
Department of Physics, Beijing Normal University, Beijing 100875, China.
School of Chemistry, Beihang University, Beijing 100191, China.
ACS Omega. 2020 Mar 27;5(13):7593-7600. doi: 10.1021/acsomega.0c00421. eCollection 2020 Apr 7.
Within the framework of a dynamic self-consistent field theory, we study the effect of the correlations in a small scale on polymer dynamics, adopting the semiflexible homopolymer blends as the model system. This is accomplished by taking the pair correlation function of ideal semiflexible chains as the Onsager coefficient and the Debye function as an approximation to the Onsager coefficient. Relying on the difference of the two pair correlation functions in the small-scale region, we can identify the effect of small-scale correlations. In the equilibrium state, with the chain length growing, the interface width has a continuous transition from the contour length to radius of gyration. The investigation of interfacial evolution and chain orientation reveals that strong small-scale correlations would accelerate the small-scale dynamic process. We also expect that such a small-scale effect should be highlighted in the process where microscopic phase separation happens.
在动态自洽场理论的框架内,我们以半柔性均聚物共混物为模型体系,研究小尺度关联对聚合物动力学的影响。这是通过将理想半柔性链的对关联函数作为昂萨格系数,并将德拜函数作为昂萨格系数的近似来实现的。依靠小尺度区域中两个对关联函数的差异,我们可以确定小尺度关联的影响。在平衡状态下,随着链长的增加,界面宽度从轮廓长度到回转半径有一个连续的转变。对界面演化和链取向的研究表明,强小尺度关联会加速小尺度动态过程。我们还预期,在微观相分离发生的过程中,这种小尺度效应应该会凸显出来。