当前位置: X-MOL 学术Macromolecules › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Effect of Chain Flexibility and Interlayer Interactions on the Local Dynamics of Layered Polymer Systems
Macromolecules ( IF 5.1 ) Pub Date : 2018-01-03 00:00:00 , DOI: 10.1021/acs.macromol.7b01519
Sriramvignesh Mani 1 , Rajesh Khare 1
Affiliation  

Layered polymeric systems are widely used in membrane separation applications; chain mobility in these layered systems is a key consideration in the design of the membranes. The transport properties of membrane polymers can be significantly altered by the perturbations in chain dynamics induced by the presence of an interface and also by the topological properties of the polymers constituting the layered systems. In this work, we use molecular dynamics (MD) simulations to determine the effects of polymer backbone flexibility and interlayer interactions on the glass transition and chain dynamics of polymer layers in the layered systems. We observed that the onset of glass transition of the entire layered system is governed by the stiffer polymer layer and is independent of the type of interactions between the layers. However, the interlayer interactions govern the strength of the glass transition of the entire layered system. Polymer mobility, on the other hand, exhibits a strong dependence on both the chain flexibility and the interlayer interactions. In systems with attractive interactions between the layers, the fully flexible polymer chains at the interface have a lower mobility than those in the bulk region of the layer; the behavior differs from that of rigid polymers, which have a higher mobility at the interface compared to that in the bulk. On the other hand, when the interactions between the layers are repulsive, each layer acts as a free-standing film with chains in both the layers exhibiting higher mobility at the interface.

中文翻译:

链柔性和层间相互作用对层状聚合物体系局部动力学的影响

层状聚合物体系广泛用于膜分离应用中。这些分层系统中的链迁移率是膜设计中的关键考虑因素。膜聚合物的传输特性可以通过界面的存在引起的链动力学扰动以及构成分层系统的聚合物的拓扑特性来显着改变。在这项工作中,我们使用分子动力学(MD)模拟来确定聚合物主链柔性和层间相互作用对分层系统中聚合物层的玻璃化转变和链动力学的影响。我们观察到整个层状体系的玻璃化转变的开始是由较硬的聚合物层控制的,并且与层之间相互作用的类型无关。然而,层间相互作用决定了整个层状体系的玻璃化转变强度。另一方面,聚合物的迁移率表现出对链柔性和层间相互作用的强烈依赖性。在层之间具有有吸引力的相互作用的系统中,界面处的完全柔性的聚合物链的迁移率低于层主体区域中的迁移率。这种行为不同于硬质聚合物,后者在界面上的迁移率要比在本体中高。另一方面,当各层之间的相互作用是排斥的时,各层充当独立的膜,两层中的链均在界面处表现出较高的迁移率。对链的柔韧性和层间相互作用都表现出强烈的依赖性​​。在层之间具有有吸引力的相互作用的系统中,界面处的完全柔性的聚合物链的迁移率低于层主体区域中的迁移率。这种行为不同于硬质聚合物,后者在界面上的迁移率要比在本体中高。另一方面,当各层之间的相互作用是排斥的时,各层充当独立的膜,两层中的链均在界面处表现出较高的迁移率。对链的柔韧性和层间相互作用都表现出强烈的依赖性​​。在层之间具有有吸引力的相互作用的系统中,界面处的完全柔性的聚合物链的迁移率低于层主体区域中的迁移率。这种行为不同于硬质聚合物,后者在界面上的迁移率要比在本体中高。另一方面,当各层之间的相互作用是排斥的时,各层充当独立的膜,两层中的链均在界面处表现出较高的迁移率。这种行为不同于硬质聚合物,后者在界面上的迁移率要比在本体中高。另一方面,当各层之间的相互作用是排斥的时,各层充当独立的膜,两层中的链均在界面处表现出较高的迁移率。这种行为不同于硬质聚合物,后者在界面上的迁移率要比在本体中高。另一方面,当各层之间的相互作用是排斥的时,各层充当独立的膜,两层中的链均在界面处表现出较高的迁移率。
更新日期:2018-01-03
down
wechat
bug