Webbläsaren som du använder stöds inte av denna webbplats. Alla versioner av Internet Explorer stöds inte längre, av oss eller Microsoft (läs mer här: * https://www.microsoft.com/en-us/microsoft-365/windows/end-of-ie-support).

Var god och använd en modern webbläsare för att ta del av denna webbplats, som t.ex. nyaste versioner av Edge, Chrome, Firefox eller Safari osv.

Characterization of free volume and density gradients of polystyrene surfaces by low-energy positron lifetime measurements

In English

Författare

  • John Algers
  • R Suzuki
  • T Ohdaira
  • Frans Maurer

Summary, in English

Free volume and density gradient widths of the free surface of high molecular mass polystyrene was characterized by use of a pulsed low-energy positron lifetime beam. A density gradient in terms of mass density (g/cm(3)) versus depth (nm) was obtained from the experimental beam data using a novel approach, yielding a width of the density gradient of approximately 3.5 nm. The procedure accounted for the broadening of the positron implantation probe as a function of energy as well as correcting for the increase in positron implantation depths due to the presence of a lower density at the surface region. Moreover, the spectra in the low implantation energy range were found to contain a long-lived lifetime that yielded very large estimates of the free volume effects at the surface. Accounting for this lifetime in the evaluation procedure, resulted in a much improved agreement with the results of other experimental and theoretical investigations in the literature. (C) 2004 Elsevier Ltd. All rights reserved.

Publiceringsår

2004

Språk

Engelska

Sidor

4533-4539

Publikation/Tidskrift/Serie

Polymer

Volym

45

Issue

13

Dokumenttyp

Artikel i tidskrift

Förlag

Elsevier

Ämne

  • Chemical Sciences

Status

Published

ISBN/ISSN/Övrigt

  • ISSN: 0032-3861