- Strong Reduction in Amplitude of the Interfacial Segmental Dynamics in Polymer Nanocomposites doi link

Auteur(s): Popov Ivan, Carroll Bobby, Bocharova Vera, Genix A.-C., Cheng Shiwang, Khamzin Airat, Kisliuk Alexander, Sokolov Alexei p.

(Article) Publié: Macromolecules, vol. 53 p.4126-4135 (2020)

Ref HAL: hal-02880945_v1
DOI: 10.1021/acs.macromol.0c00496
WoS: WOS:000537677300050
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Despite the wide use of polymer nanocomposites (PNCs)in various applications, our understanding of the microscopic parameterscontrolling their macroscopic properties remains limited. In this study, weexamine the dielectric strength of segmental dynamics, ΔεIL(T) in theinterfacial polymer layer surrounding the nanoparticles in PNCs. Thepresented analysis reveals a significant drop in ΔεIL(T) and its anomaloustemperature dependence in the polymer layer adsorbed to nanoparticles.The drop in ΔεIL(T) was observed in all samples regardless of whethersegmental relaxation time in the interfacial layer was slower or faster thanin the bulk polymer, excluding interpretation of the “dead” layer. Weascribe the observed decrease in the dielectric strength to the restrictedamplitude of segmental relaxation in the interfacial/adsorbed layer. Ourresults provide a new perspective on discussion of dynamics in theinterfacial layer in PNCs and thin polymer films, demonstrating that notonly segmental relaxation time but also its amplitude can be strongly affected by the interface.