Direct Structural Evidence for Interfacial Gradients in Asymmetric Polymer Nanocomposite Blends - Laboratoire Charles Coulomb (L2C) Accéder directement au contenu
Article Dans Une Revue ACS Applied Materials & Interfaces Année : 2021

Direct Structural Evidence for Interfacial Gradients in Asymmetric Polymer Nanocomposite Blends

Résumé

Understanding the complex structure of polymer blends filled with nanoparticles (NPs) is the key to designing their macroscopic properties. Here, the spatial distribution of hydrogenated (H) and deuterated (D) polymer chains asymmetric in mass is studied by small-angle neutron scattering. Depending on the chain mass, a qualitatively new large-scale organization of poly(vinyl acetate) chains beyond the random-phase approximation is evidenced in nanocomposites with attractive polymersilica interactions. The silica is found to systematically induce bulk segregation. Only with long H-chains, a strong scattering signature is observed in the q-range of the NP size: it is the sign of interfacial isotopic enrichment, i.e., of contrasted polymer shells close to the NP surface. A quantitative model describing both the bulk segregation and the interfacial gradient (over ca. 10-20 nm depending on the NP size) is developed, showing that both are of comparable strength. In all cases, NP surfaces trap the polymer blend in a non-equilibrium state, with preferential adsorption around NPs only if chain length and isotopic preference towards the surface combine their entropic and enthalpic driving forces. This structural evidence for interfacial polymer gradients will open the road to quantitative understanding of the dynamics of many-chain nanocomposite systems.
Fichier principal
Vignette du fichier
DirectEvidence_AMI_2021.pdf (1.45 Mo) Télécharger le fichier
Origine : Fichiers produits par l'(les) auteur(s)

Dates et versions

hal-03384179 , version 1 (18-10-2021)

Identifiants

Citer

Anne-Caroline Genix, Vera Bocharova, Bobby Carroll, Philippe Dieudonné-George, Michael Sztucki, et al.. Direct Structural Evidence for Interfacial Gradients in Asymmetric Polymer Nanocomposite Blends. ACS Applied Materials & Interfaces, 2021, 13 (30), pp.36262-36274. ⟨10.1021/acsami.1c06971⟩. ⟨hal-03384179⟩
58 Consultations
74 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More