Molecular mobility in supported thin films of polystyrene, poly(methyl methacrylate), and poly(2-vinyl pyridine) probed by dye reorientation

Keewook Paeng, Ranko Richert, M. D. Ediger

Research output: Contribution to journalArticlepeer-review

95 Scopus citations

Abstract

Temperature-ramping anisotropy measurements were used to probe the molecular mobility of fluorescent probes in polystyrene, poly(methyl methacrylate), and poly(2-vinyl pyridine) films supported upon silicon wafers with native oxide coatings. All polymer films showed evidence of high mobility at the free surface. The fraction of a film with high mobility was characterized as a mobile surface layer thickness, which increased with temperature. The mobile surface layer thickness for supported films of polystyrene and poly(methyl methacrylate) reasonably matched that previously deduced from freestanding films of these polymers; for poly(methyl methacrylate), enhanced mobility extends about 4 nm into the film from the free surface at T g. For supported polystyrene and poly(methyl methacrylate) films, the results are consistent with no decrease in mobility near the solid substrate but do not eliminate this possibility. On the other hand, the mobility of supported poly(2-vinyl pyridine) thin films provides some evidence for slower-than-bulk relaxation near the solid substrate.

Original languageEnglish (US)
Pages (from-to)819-826
Number of pages8
JournalSoft Matter
Volume8
Issue number3
DOIs
StatePublished - Jan 21 2012

ASJC Scopus subject areas

  • Chemistry(all)
  • Condensed Matter Physics

Fingerprint Dive into the research topics of 'Molecular mobility in supported thin films of polystyrene, poly(methyl methacrylate), and poly(2-vinyl pyridine) probed by dye reorientation'. Together they form a unique fingerprint.

Cite this