Photophysical study of fluorene phenylene-vinylene copolymer (PFO-MEHPV) blended with poly(vinylcarbazole)

Author(s)

Bruna Médici Amorim Bonon

• Document type: Master's Dissertation
• Press: Campinas, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Instituto de Química
• Defense date: 2012-03-28

Examining board members

Teresa Dib Zambon Atvars; René Alfonso Nome Silva; Roberto Mendonça Faria

• Advisor: Teresa Dib Zambon Atvars

Abstract

The energy transfer processes were studied for mixtures of PVK and PFO-MEHPV, which are two polymers that have a strong overlap between the donor emission spectrum and the acceptor absorption spectrum, in both solutions and films and with several relative proportions of the two components. The emission decay of neat PVK is much slower than that of PFO-MEHPV, which may favor the non-radiative energy transfer process. The steady-state PL spectra of PVK exhibited an intensity decrease in the presence of PFO-MEHPV, but the decrease in the the PVK lifetime does not follow the same trend upon increasing the donor concentration. Thus, it has been assumed that the intensity decrease was more strongly correlated with the trivial energy transfer than with FRET process by the Föster mechanism. The low FRET efficiency may be attributed to the presence of several types of the others PVK photophysical processes that quench the excited state via FRET process. Nevertheless, the solid-state polymer blends undergo Förster-type energy transfer more efficiently in addition to the trivial process, as demonstrated by the relative increase in the emission intensity of the acceptor following the donor excitation and the decrease in the donor PL lifetime. Moreover, in films, there are two concentration ranges in which the donor lifetime exhibited an additional decrease, and these concentration ranges are coincident with those at which changes in the morphology were observed using SEM (AU)

• FAPESP's process: 10/02486-0 - Photophysical and electroluminescence of polyfluorene and poly(vinyl carbazol) blends
• Grantee: Bruna Médici Amorim Bonon
• Support Opportunities: Scholarships in Brazil - Master