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.

Default user image.

Oleg Mirzov

Systemarkitekt

Default user image.

Single chain versus single aggregate spectroscopy of conjugated polymers. Where is the border?

Författare

  • Hongzhen Lin
  • Ralph Hania
  • Robert Bloem
  • Oleg Mirzov
  • Daniel Thomsson
  • Ivan Scheblykin

Summary, in English

Single chains of conjugated polymers e.g. MEH-PPV (poly(2-methoxy-5-(2'-ethylhexyloxy)-1,4-phenylenevinylene) have become interesting objects for single molecule spectroscopy (SMS) studies. However, most of the experiments so far were performed without full awareness of the isolation status of the polymer chains in host matrices. We used steady-state and time-resolved fluorescence methods and 2D polarization single molecule imaging technique to unravel the isolation/aggregation status of MEH-PPV in spin-coated films prepared at different conditions. It turned out that a sample showing isolated bright spots in fluorescence images could be obtained in a very broad concentration range of MEH-PPV when toluene was used as a solvent and PMMA as a matrix. If the MEH-PPV concentration was not sufficiently low, a substantial fraction of the fluorescence spots should be assigned to individual nano-aggregates rather than truly isolated chains of the polymer. Contrary to single aggregates, truly isolated MEH-PPV chains showed blue-shifted emission spectra, mono-exponential fluorescence decay dynamics with relatively long lifetimes (0.4-1.2 ns), and high polarization anisotropy. We argue that insufficient control of the concentration in the published SMS studies of MEH-PPV resulted in incorrect assigning of some spectroscopic properties of single aggregates to isolated MEH-PPV chains. We believe this to be the main origin of discrepancies among the published data in this field.

Avdelning/ar

  • Kemisk fysik
  • NanoLund: Centre for Nanoscience

Publiceringsår

2010

Språk

Engelska

Sidor

11770-11777

Publikation/Tidskrift/Serie

Physical chemistry chemical physics : PCCP

Volym

12

Dokumenttyp

Artikel i tidskrift

Förlag

Royal Society of Chemistry

Ämne

  • Atom and Molecular Physics and Optics

Status

Published

ISBN/ISSN/Övrigt

  • ISSN: 1463-9084