Grafted Nanoparticle Surface Wetting during Phase Separation in Polymer Nanocomposite Films - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue ACS Applied Materials & Interfaces Année : 2021

Grafted Nanoparticle Surface Wetting during Phase Separation in Polymer Nanocomposite Films

Résumé

Wetting of polymer-grafted nanoparticles (NPs) in a polymer nanocomposite (PNC) film is driven by a difference in surface energy between components as well as bulk thermodynamics, namely, the value of the interaction parameter, χ. The interplay between these contributions is investigated in a PNC containing 25 wt % polymethyl methacrylate (PMMA)-grafted silica NPs (PMMA-NPs) in poly(styrene-ran-acrylonitrile) (SAN) upon annealing above the lower critical solution temperature (LCST, 160 °C). Atomic force microscopy (AFM) studies show that the areal density of particles increases rapidly and then approaches 80% of that expected for random close-packed hard spheres. A slightly greater areal density is observed at 190 °C compared to 170 °C. The PMMA-NPs are also shown to prevent dewetting of PNC films under conditions where the analogous polymer blend is unstable. Transmission electron microscopy (TEM) imaging shows that PMMANPs symmetrically wet both interfaces and form columns that span the free surface and substrate interface. Using grazingincidence Rutherford backscattering spectrometry (GI-RBS), the PMMA-NP surface excess (Z*) initially increases rapidly with time and then approaches a constant value at longer times. Consistent with the areal density, Z* is slightly greater at deeper quench depths, which is attributed to the more unfavorable interactions between the PMMA brush and SAN segments. The Z* values at early times are used to determine the PMMA-NP diffusion coefficients, which are significantly larger than theoretical predictions. These studies provide insights into the interplay between wetting and phase separation in PNCs and can be utilized in nanotechnology applications where surface-dependent properties, such as wettability, durability, and friction, are important.
Fichier principal
Vignette du fichier
AcceptedManuscript-GraftedNanoparticleSurfaceWettingDuringPhaseSeparationinPolymerNanocompositeFilms.pdf (830.45 Ko) Télécharger le fichier
Origine : Fichiers produits par l'(les) auteur(s)

Dates et versions

hal-03418118 , version 1 (06-11-2021)

Identifiants

Citer

Shawn M Maguire, Michael J Boyle, Connor R Bilchak, John Derek Demaree, Austin W Keller, et al.. Grafted Nanoparticle Surface Wetting during Phase Separation in Polymer Nanocomposite Films. ACS Applied Materials & Interfaces, 2021, 13 (31), pp.37628-37637. ⟨10.1021/acsami.1c09233⟩. ⟨hal-03418118⟩
35 Consultations
118 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More