Effects of Chain Length on the Structure and Dynamics of Polymer Composites

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Live Poster Session: Zoom Link
Thursday, July 30th 1:15-2:30pm EDT

Ari Liu
Ari Liu

Ari Liu (they/them/their) just graduated as a physics, psychology, and Russian studies triple major, and is going to be a BA/MA student in physics. They plan to pursue a PhD afterwards. Born and raised in Guangdong, China, they graduated from the Affiliated High School of South China Normal University. Ari is passionate about food (exploring different cuisines and food culture but not cooking), reading books (especially Russian literature), and (most importantly) music. They play the piano both as a soloist and with the concert choir, orchestra, and in several music theater productions; they also write music occasionally. 

Abstract: We use molecular dynamics simulations to study the effect of chain length on the properties of polymer-nanoparticle (NP) composites. We show that polymers slightly elongate near the NP interface and chains tend to align their longest axis with the NP interface. The effect of NP on chain structure is chain length independent, whereas the effect on chain alignment extends farther from the NP surface as chain length increases. When we distinguish chains that bridge between NP, we find that they are significantly elongated when the NP separation is large compared to chain dimensions. Dynamically, these bridging chains have a longer relaxation time than non-bridging chains, but they do not have a substantial effect on the overall relaxation of the composites. Accordingly, the variation of glass transition temperature Tg with chain length essentially mirrors that observed for pure polymer systems, where Tg increases with chain length and then saturates approaching the entanglement length.

Poster-Ari-Liu-2020-Ari-Liu

Live Poster Session: Zoom Link
Thursday, July 30th 1:15-2:30pm EDT

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