Poly(ether imide) Alumina Nanocomposites: Interphase Properties Determined from Free Volume Element Radius Distributions

• DOI: 10.1021/acs.macromol.4c00868
• Publication Date: 2024-06-29T13:26:48Z
• Authors: Junkun Pan; Aaron P. Charnay; Michael D. Fayer
• Keywords: Interphase; Imide

Ultrafast infrared (IR) spectroscopy was used to characterize the free volume element (FVE) radius probability distributions (RPDs) of poly(ether imide) (PEI) alumina nanocomposites. The nanocomposites (0–2 wt %) were prepared with 20 nm diameter spherical Al2O3 nanofillers and a small amount phenyl selenocyanate (PhSeCN) as IR vibrational probes. Restricted orientation anisotropy method (ROAM), an ultrafast technique, measure FVE radii. results yield RPDs function nanoparticle concentration. decomposed into bulk PEI interphase region contributions. ROAM demonstrate that polymer chain packing in is significantly altered from pure PEI. average increases increasing nanofiller content. indicate subensembles smaller radii are disproportionately affected by presence nanofillers, causing width distribution narrow. for interface regions reveal ∼0.2 Å larger but narrower than distribution. Finally, fraction each nanocomposite sample determined differences RPD curves, effective interfacial layer thickness found be 19.2 ± 0.5 nm. demonstrated characteristics strongly proximity nanoparticles. nature FVEs provides information about microscopic origin material's properties.