(322b) Viscoelastic Behavior of Grafted-Nanoparticle/Polymer Composites | AIChE

(322b) Viscoelastic Behavior of Grafted-Nanoparticle/Polymer Composites

Authors 

Hattemer, G. - Presenter, University of California, San Diego
Arya, G., University of California San Diego
Arman, B., University of California, San Diego



Polymer-grafted nanoparticles are frequently used to enhance the physical properties of polymers, where the nanoparticle core serves to enhance the mechanical properties of the host polymer and the grafted polymer serves to integrate the nanoparticles with the matrix and to prevent nanoparticle aggregation. Despite significant advances, a fundamental understanding of how and why grafted-nanoparticles modulate the viscoelastic properties of polymers is still lacking. Here we employ coarse-grained models of polymer-nanoparticle composites and exhaustive molecular dynamics simulations to dissect the role of various nanoparticle-related parameters on the frequency-dependent storage G’ and loss modulus G” of polymer nanocomposites. Specifically, we examine the effects of: size, shape, and loading of nanoparticles; surface density and length of grafted polymer, and chemical compatibility of the grafted polymer with host polymer. We provide molecular-level explanations for all observed trends and our results largely agree with the trends obtained experimentally from dynamic mechanical tests.