Structure and Entanglement Factors on Dynamics of Polymer-Grafted Nanoparticles

Journal Article · Fri Apr 15 00:00:00 EDT 2016 · ACS Macro Letters

DOI:https://doi.org/10.1021/acsmacrolett.6b00089· OSTI ID:1339949

Liu, Siqi ^[1]; Senses, Erkan ^[1]; Jiao, Yang ^[1]; Narayanan, Suresh ^[2]; Akcora, Pinar ^[1]

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1. Stevens Inst. of Technology, Hoboken, NJ (United States). Dept. of Chemical Engineering and Materials Science
2. Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source

Nanoparticles functionalized with long polymer chains at low graft density are interesting systems to study structure–dynamic relationships in polymer nanocomposites since they are shown to aggregate into strings in both solution and melts and also into spheres and branched aggregates in the presence of free polymer chains. Our work investigates structure and entanglement effects in composites of polystyrene-grafted iron oxide nanoparticles by measuring particle relaxations using X-ray photon correlation spectroscopy. And for particles within highly ordered strings and aggregated systems, they experience a dynamically heterogeneous environment displaying hyperdiffusive relaxation commonly observed in jammed soft glassy systems. Furthermore, particle dynamics is diffusive for branched aggregated structures which could be caused by less penetration of long matrix chains into brushes. These results suggest that particle motion is dictated by the strong interactions of chains grafted at low density with the host matrix polymer.

• Research Organization: Argonne National Lab. (ANL), Argonne, IL (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES); National Science Foundation (NSF)
• Grant/Contract Number: AC02-06CH11357
• OSTI ID: 1339949
• Journal Information: ACS Macro Letters, Vol. 5, Issue 5; ISSN 2161-1653
• Publisher: American Chemical Society
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE