Segmental dynamics in lamellar phases of tapered copolymers.
Segmental dynamics in lamellar phases of tapered copolymers.
复制标题
递变共聚物层状相的链段动力学。
作者：
Vaidyanathan Sethuraman;V. Ganesan
最近的实验报道了盐掺杂锥形共聚物的片层相比类似形态的二嵌段共聚物表现出更高的离子电导率。通过调用分离共聚物的相应玻璃化转变温度，反过来使这些观察结果合理化。在这项工作中，我们报告了粗粒度分子动力学模拟的结果，以确定这些特征背后的机制。明确地，我们探讨了偏析程度和两个块段的迁移率差异对在层状相中偏析的锥形共聚物的局部弛豫动力学的综合影响。我们的研究结果表明，锥形共聚物的局部动力学取决于两个独立的因素，即，这种共聚物的偏析程度相对于它们的有序-无序转变温度，以及两个嵌段的相对迁移率（玻璃化转变温度）。通过与实验的定性对应，我们发现，对于迁移率和偏析程度的适当组合，锥形共聚物的片层相比二嵌段共聚物表现出更快的局部段动力学。
Recent experiments have reported that the lamellar phase of salt-doped tapered copolymers exhibit higher ionic conductivity compared to those seen in similar morphologies of diblock copolymers. Such observations were in turn rationalized by invoking the corresponding glass transition temperature of the segregated copolymers. In this work we report the results of coarse-grained molecular dynamics simulations to identify the mechanisms underlying such characteristics. Explicitly, we probe the combined influences of the degree of segregation and the disparity in mobilities of the segments of the two blocks, upon the local relaxation dynamics of tapered copolymers segregated in lamellar phases. Our results show that the local dynamics of tapered copolymers depend on two independent factors, viz., the degree of segregation of such copolymers relative to their order-disorder transition temperature, and the relative mobilities (glass transition temperatures) of the two blocks. In qualitative correspondence with experiments, we find that for appropriate combinations of mobility ratios and degree of segregation, the lamellar phases of tapered copolymers can exhibit faster local segmental dynamics compared to diblock copolymers.
影响因子：
3.4
作者：
Glaser, Jens;Qin, Jian;Morse, David C.
通讯作者：
Morse, David C.