Por favor, use este identificador para citar o enlazar a este item: http://hdl.handle.net/10261/101813
COMPARTIR / EXPORTAR:
logo share SHARE logo core CORE BASE
Visualizar otros formatos: MARC | Dublin Core | RDF | ORE | MODS | METS | DIDL | DATACITE

Invitar a revisión por pares abierta
Título

Enthalpy recovery in nanometer to micrometer thick polystyrene films

AutorBoucher, Virginie M. CSIC ORCID; Cangialosi, Daniele CSIC ORCID ; Alegría, Ángel CSIC ORCID ; Colmenero de León, Juan CSIC ORCID
Fecha de publicación2012
EditorAmerican Chemical Society
CitaciónMacromolecules 45(12): 5296-5306 (2012)
ResumenThe physical aging of polystyrene (PS) free-standing films has been investigated as a function of the films thickness, ranging from several micrometers to tens of nanometers. In this range of thicknesses, unchanged segmental dynamics in comparison to the bulk was previously reported. This study has been carried out through differential scanning calorimetry (DSC), by following the enthalpy recovery to monitor the physical aging process at different temperatures. The temperature marking the onset of nonequilibrium effects, that is the onset of the glass transtion temperature, T g on, was also assessed, at different cooling rates. An acceleration of the physical aging process, and consequently a depression of T g on, is found with decreasing the films thickness, already for thicknesses in the micrometer range. Moreover, the onset of nonequilibrium effects is shown to be cooling rate dependent, this being more pronounced when the PS films get thinner. The thickness effects on the typical signatures of the out-of-equilibrium dynamics of the films, namely their physical aging and T g on, can be well accounted for by assuming an equilibration mechanism based on volume holes diffusion toward the interfaces of the films. The temperature dependence of the diffusion coefficient obtained within this framework is found to crossover from Vogel-Fulcher-Tammann (VFT) to Arrhenius when decreasing the temperature. The implications of these results are discussed. © 2012 American Chemical Society.
URIhttp://hdl.handle.net/10261/101813
DOI10.1021/ma300622k
Identificadoresdoi: 10.1021/ma300622k
issn: 0024-9297
e-issn: 1520-5835
Aparece en las colecciones: (CFM) Artículos




Ficheros en este ítem:
Fichero Descripción Tamaño Formato
accesoRestringido.pdf15,38 kBAdobe PDFVista previa
Visualizar/Abrir
Mostrar el registro completo

CORE Recommender

SCOPUSTM   
Citations

75
checked on 19-mar-2024

WEB OF SCIENCETM
Citations

69
checked on 19-feb-2024

Page view(s)

387
checked on 26-mar-2024

Download(s)

103
checked on 26-mar-2024

Google ScholarTM

Check

Altmetric

Altmetric


NOTA: Los ítems de Digital.CSIC están protegidos por copyright, con todos los derechos reservados, a menos que se indique lo contrario.