1D-Confinement Inhibits the Anomaly in Secondary Relaxation of a Fluorinated Polymer.
ACS Macro Lett
; 10(5): 649-653, 2021 May 18.
Article
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| MEDLINE
| ID: mdl-35570757
ABSTRACT
We present an experimental study of the dynamics of a well-pronounced secondary relaxation observed in bulk and ultrathin films of the fluorinated copolymer poly(vinylidene fluoride-co-hexafluoropropylene) (PVdF-HFP). In proximity to the glass transition, an anomalous phenomenon is observed the ß-relaxation slows down upon heating. Measurements as a function of the film thickness show that this exceptional behavior gradually vanishes upon confinement at the nanoscale level. Regardless of sample size, the relaxation dynamics could be described in terms of the Minimal Model via an asymmetric double well potential. Supported by a structural investigation of surfaces and interfaces, our results reveal that the presence of adsorbing walls induces an increase in glass transition temperature, which counterbalances the asymmetry in the double well potential responsible for molecular motion.
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Colección:
01-internacional
Base de datos:
MEDLINE
Idioma:
En
Revista:
ACS Macro Lett
Año:
2021
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Article
País de afiliación:
Bélgica
Pais de publicación:
EEUU
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ESTADOS UNIDOS
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ESTADOS UNIDOS DA AMERICA
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EUA
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UNITED STATES
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UNITED STATES OF AMERICA
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US
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USA