Wetting-Dewetting and Dispersion-Aggregation Transitions are Distinct for Polymer Grafted Nanoparticles in Chemically Dissimilar Polymer Matrix

Published

August 26, 2015

Author(s)

Tyler B. Martin, Katrina Irene S. Mongcopa, Rana N. Ashkar, Paul Butler, Ramanan Krishnamoorti, Arthi Jayaraman

Abstract

Simulations and experiments are conducted on polymer mixtures (or blends) containing polymer grafted nanoparticles in a chemically distinct polymer matrix, where the graft and matrix polymers exhibit attractive enthalpic interactions. Both coarse-grained molecular dynamics simulations, and x-ray scattering and neutron scattering experiments with deuterated polystyrene (dPS) grafted silica and poly(vinyl-methyl-ether) PVME matrix show that the sharp phase transition from dispersed to aggregated states due to increasingly repulsive effective interactions between the blend components is distinct from the continuous wetting-dewetting transition. Strikingly, this is unlike the extensively-studied chemically identical graft-matrix composites, where the two transitions have been considered to be synonymous, and is also unlike the free (ungrafted) blends of the same graft and matrix homopolymers, where the wetting-dewetting is a sharp transition coinciding with the macrophase separation.

Citation

Journal of American Chemical Society

Volume

137

Issue

33

Pub Type

Journals

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Keywords

wetting transition, particle aggregation, nanocomposites, chemically dissimilar brush/matrix

Citation

Martin, T. , Mongcopa, K. , Ashkar, R. , Butler, P. , Krishnamoorti, R. and Jayaraman, A. (2015), Wetting-Dewetting and Dispersion-Aggregation Transitions are Distinct for Polymer Grafted Nanoparticles in Chemically Dissimilar Polymer Matrix, Journal of American Chemical Society, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=918624 (Accessed October 14, 2025)