Enhanced Dynamics of Confined Polymers near the Immiscible Polymer-Polymer Interface: Neutron Reflectivity Studies

Published

February 18, 2020

Author(s)

Kyoung-Il Jo, Younghoon Oh, Bong June Sung, Tae-Ho Kim, Min Seop Um, Woo Jin Choi, Joona Bang, Guangcui Yuan, Sushil K. Satija, Jaseung Koo

Abstract

For polymer-blend films, local dynamics in confined polymer domains tend to differ from the bulk due to significant contributions from the polymer-polymer interface. Herein, we investigated the diffusion dynamics of entangled polymer thin films confined between different polymers using neutron reflectivity. We found that a bilayer of polymethylmethacrylate (PMMA) and deuterated PMMA (dPMMA) sandwiched between polystyrene (PS) layers exhibited significant increase in mobility near the polymer-polymer interface with decreasing PMMA thickness. This indicates that the contribution of repulsive interactions at the immiscible polymer-polymer interface becomes more significant as the film thickness decreases. We also found that the interfacial roughness between PMMA and PS (28 angstrom} at equilibrium) and soft confinement of PS layers did not significantly affect the change in the diffusion dynamics of the adjacent PMMA. This was evidenced by comparing with the diffusion results of multilayers with a flat interface (8 angstrom} at equilibrium) between PMMA and hard PS by UV-crosslinking.

Citation

ACS Macro Letters

Volume

9

Issue

2

Pub Type

Journals

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Keywords

Dynamics, Confined Polymer, Neutron Reflectivity

Citation

Jo, K. , Oh, Y. , Sung, B. , Kim, T. , Um, M. , Choi, W. , Bang, J. , Yuan, G. , Satija, S. and Koo, J. (2020), Enhanced Dynamics of Confined Polymers near the Immiscible Polymer-Polymer Interface: Neutron Reflectivity Studies, ACS Macro Letters, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=929544 (Accessed October 18, 2025)