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This content will become publicly available on September 17, 2025

Title: Nanoparticle Diffusion in Crowded Polymer Nanocomposite Melts
This study examines nanoparticle diffusion in crowded polymer nanocomposites by diffusing small Al2O3 nanoparticles (NPs) in SiO2-loaded P2VP matrices. Time-of-flight secondary ion mass spectroscopy (ToF-SIMS) measures Al2O3 NP diffusion coefficients within a homogeneous PNC background of larger, immobile SiO2 NPs. By developing a geometric model for the average interparticle distance in a system with two NP sizes, we quantify nanocomposite confinement relative to the Al2O3 NP size with a bound layer. At low SiO2 concentrations, Al2O3 NP diffusion aligns with the neat polymer results. In more crowded nanocomposites with higher SiO2 concentrations where the interparticle distance approaches the size of the mobile Al2O3 NP, the 6.5 nm Al2O3 NPs diffuse faster than predicted by both core–shell and vehicular diffusion models. Relative to our previous studies of NPs diffusing into polymers, these findings demonstrate that the local environment in crowded systems significantly complicates NP diffusion behavior and the bound layer lifetimes.  more » « less
Award ID(s):
2034122
PAR ID:
10550853
Author(s) / Creator(s):
;
Publisher / Repository:
American Chemical Society (ACS)
Date Published:
Journal Name:
ACS Macro Letters
Volume:
13
Issue:
9
ISSN:
2161-1653
Page Range / eLocation ID:
1192 to 1197
Subject(s) / Keyword(s):
Diffusion, layers, nanocomposites, nanoparticles, polymers
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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