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DTSTAMP:20260413T101608
DTSTART:20160323T140000
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DTEND:20160323T153000
URL:https://murmitoyen.com/events/vanille/udem/detail/682614
LOCATION:Université de Montréal - Pavillon Claire-McNicoll\, 2900\, chemi
 n de la Tour\, Montréal\, QC\, Canada\, H3T 1J6
SUMMARY:Conférence du Professeur Shinjiro Machida (KIT)
DESCRIPTION:Titre : Fluorescence Behavior of Single Polyfluorene Nanopartic
 les.Endroit : Pavillon Claire-McNicoll\, salle Z-330 à 14 h.Hôte : Profe
 sseure Julian Zhu.
\nCette conférence sera prononcée par le professeur 
 Shinjiro Machida du Département des sciences macromoléculaires et de gé
 nie au Kyoto Institute of Technology.
\nRésumé :Conjugated polymers are 
 expected to be applied to optoelectronic devices\, such as light-emitting 
 device and solar cell. The nanoparticles of the conjugated polymers are al
 so studied as probes for bioimaging with lower toxicity compared to semico
 nductor quantum dots. Poly(9\,9-di-n-octylfuluorenyl-2\,7-diyl) (PFO) is o
 ne of the well-studied conjugated polymer showing bright fluorescence in t
 he aggregated state. In particular\, the PFO nanoparticles containing a cr
 ystalline phase (called β-phase) are reported to exhibit higher fluoresce
 nce quantum yield (0.40) than the nanoparticles of other conjugated polyme
 rs. For the imaging applications\, it is important to reveal the photolumi
 nescent characteristics of the conjugated polymer nanoparticles at the sin
 gle particle level. In this study\, we measured the time traces of the flu
 orescence intensity and the polarization degree of single PFO nanoparticle
 s with different particle size and the degree of cristallinity. The prepar
 ed PFO nanoparticles containing β-phase showed stronger and red-shifted f
 luorescence compared to those in amorphous phase. According to Hambury-Bro
 wn and Twiss type photon correlation measurements\, no photon antibunching
  was observed for the nanoparticles with sizes of 5-60nm\, indicating that
  there are more than several emissive sites in a single PFO nanoparticle. 
 In addition\, discontinuous fluctuations were observed in both the emissio
 n intensity and the polarization degree of single nanoparticles. The ampli
 tudes of such fluctuations werelarger for the nanoparticles with smaller s
 ize and higher crystallinity. These results indicated that these fluctuati
 ons were induced by the change in the emission quantum yield in each cryst
 alline phase.
\nRéférences bibliographiques : Wu\, C.\; Bull\, B. Szyma
 nski\, C.\; Christensen\, K.\; McNeill\, J. ACS Nano\, 2008\, 2\, 2415.
\n
 Information supplémentaireAnnonce PDF de la conférence
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