Nanoscale Particle Motion Reveals Polymer Mobility Gradient in Nanocomposites

Journal Article · Wed May 01 00:00:00 EDT 2019 · ACS Macro Letters

DOI:https://doi.org/10.1021/acsmacrolett.9b00176· OSTI ID:1559454

Senses, Erkan ^[1]; Narayanan, Suresh ^[2]; Faraone, Antonio ^[3]

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1. Koç Univ., Istanbul (Turkey)
2. Argonne National Lab. (ANL), Argonne, IL (United States)
3. NIST Center for Neutron Research, Gaithersburg, MD (United States)

Polymer mobility near nanoparticle surfaces has been extensively discussed; however, direct experimental observation in the nanocomposite melts has been a difficult task. Here, by taking advantage of large dynamical asymmetry between the miscible matrix and surface-bound polymers, we highlighted their interphases and studied the resulting effect on the nanoparticle relaxation using X-ray photon correlation spectroscopy. Here, the local mobility gradient is signified by an unprecedented increase in the relaxation time at length scales on the order of polymer radius of gyration. The effect is accompanied by a transition from simple diffusive to subdiffusive behavior in accord with viscous and entangled dynamics of polymers in the matrix and in the interphase, respectively. Our results demonstrate that the nanoparticle-induced polymer mobility changes in the interphases of nanocomposite melts can be extracted from the length-scale-dependent slow particle motion.

• Research Organization: Argonne National Lab. (ANL), Argonne, IL (United States)
• Sponsoring Organization: National Science Foundation (NSF); USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
• Grant/Contract Number: AC02-06CH11357
• OSTI ID: 1559454
• Journal Information: ACS Macro Letters, Journal Name: ACS Macro Letters Journal Issue: 5 Vol. 8; ISSN 2161-1653
• Publisher: American Chemical Society (ACS)
• Country of Publication: United States
• Language: English

Related Subjects

77 NANOSCIENCE AND NANOTECHNOLOGY
bound polymer
interface
interphase
nanoparticle dynamics
polymer nanocomposites