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This study investigates the interplay between film thickness and the surface and internal morphologies in polymer nanocomposite (PNC) films. The PNC is 25 wt.% poly(methyl methacrylate)-grafted silica nanoparticles (NPs) in poly(styrene-ran-acrylonitrile) annealed in the two-phase region. At greatest confinement (120 nm), NP surface density remains constant and lateral phase separation is inhibited upon annealing. For thicker films (240 nm to 1400 nm), surface density increases with time before approaching ca. 740 NP/μm2, consistent with 2D random close packing. Moreover, lateral domain growth exhibits a dimensional crossover as thickness increases from 𝑡 to , consistent with domain coalescence. Water contact angles 1/2 𝑡1/3 decrease upon annealing in agreement with the lateral domain composition. For thickest films (1400 nm to 4000 nm), a morphology map summarizes the distinct internal arrangements of NPs: disordered aggregates, continuous vertical pillars, discrete vertical pillars, isolated domains, and random networks. This study of PNC films provides guidance for controlling surface and bulk structure which can lead to improved barrier, mechanical and transport properties.
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This content will become publicly available on May 30, 2026
Motion of islands of elastic thin films in the dewetting regime
This paper addresses a two-dimensional sharp interface variational model for solid-state dewetting of thin films with surface energies, introduced byWang, Jiang, Bao, and Srolovitz in Jiang et al. (Scr Mater 115:123–127, 2016). Using the H−1-gradient flow structure of the evolution law, short-time existence for a surface diffusion evolution equation with curvature regularization is established in the context of epitaxially strained two-dimensional films. The main novelty, as compared to the study of the wetting regime, is the presence of moving contact lines.
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- Award ID(s):
- 2108784
- PAR ID:
- 10633953
- Editor(s):
- Mondino, Andre; Neves, Andre; Szekelyhidi, Laszlo
- Publisher / Repository:
- Springer
- Date Published:
- Journal Name:
- Calc. Var. Partial Differential Equations
- Edition / Version:
- 1
- Volume:
- 64
- Issue:
- 110
- ISSN:
- 0944-2669
- Page Range / eLocation ID:
- 1-72
- Subject(s) / Keyword(s):
- 35K25 35B65 74K35
- Format(s):
- Medium: X Size: 1.2MB Other: pdf
- Size(s):
- 1.2MB
- Sponsoring Org:
- National Science Foundation
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