Position-Dependent Diffusion Dynamics of Entangled Polymer Melts Nanoconfined by Parallel Immiscible Polymer Films
: 159 : 2020.12.08 00:00
ACS MACRO LETTERS
Sung, Bong June & Oh, Younghoon 2020.10.20
Position-Dependent Diffusion Dynamics of Entangled Polymer Melts Nanoconfined by Parallel Immiscible Polymer Films [ 1 ]‎ Korea Atom Energy Res Inst KAERI, Neutron Sci Ctr, Daejeon 34057, South Korea [ 2 ]‎ Korea Univ, Dept Chem & Biol Engn, Seoul 02841, South Korea [ 3 ]‎ Sogang Univ, Dept Chem, Seoul 04107, South Korea [ 4 ]‎ Sogang Univ, Res Inst Basic Sci, Seoul 04107, South Korea [ 5 ]‎ Chungnam Natl Univ, Dept Organ Mat Engn, Daejeon 34134, South Korea [ 6 ]‎ NIST, NIST Ctr Neutron Res, Gaithersburg, MD 20899 USA The morphological structure and dynamics of confined polymers adjacent to the polymer-polymer interface have a profound effect on determining the overall physical properties of polymer blends. We measured the diffusion dynamics of poly(methyl methacrylate) (PMMA) melts confined between polystyrene (PS) layers using neutron reflectivity. Combinations of various thicknesses of PMMA and deuterated PMMA (dPMMA allowed us to experimentally reveal the nonmonotonic behavior of polymer mobility near the PS-PMMA interface. From the neutron reflectivity results, we found that the polymers adjacent to the immiscible polymer-polymer interface showed enhanced diffusion dynamics because of the repulsive interaction between PS and PMMA, whereas the polymer at local regions farther from the interface exhibited reduced dynamics. This is probably due to the nonspherical conformation of PMMA and spatial confinement near the PS-PMMA interface. https://pubs.acs.org/doi/abs/10.1021/acsmacrolett.0c00608

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