(746b) Role of Interfacial Interactions and Chain Flexibility in Density and Concentration Fluctuations of Layered Polymer Systems

Recent simulations on layered polymer systems (Mani and Khare, Macromolecules, 51 (2), 576-588, 2018) have shown interesting links between chain dynamics, flexibility, and intermolecular interactions. Specifically, it was observed that the mobility of the chains in the bulk is not affected by the presence of an interface; however, the dynamics close to the interface depends on several factors such as chain flexibility and interlayer interactions. Further, it also important to study the effect of these factors on the compatibility of the layers as such complete understanding will lead to a better design of layered polymer systems for several applications. In this work, we probe the density and concentration fluctuations of unsupported and layered polymer systems with varied flexibilities and interlayer interactions. The density fluctuations in unsupported flexible polymer systems are higher when compared to the semi-flexible counterparts due to higher configurational entropy of flexible chains. The bulk of the layered systems exhibit a similar behavior to that of the respective unsupported systems with slight perturbations due to the interfacial interactions. On the other hand, interlayer interactions have a significant effect on the concentration fluctuations at the interface which are discussed in detail.