Spectroscopic studies of different poly3hexylthiophene chain environments in a polyfluorene matrix

Abstract

Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-pro t purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. AbstractOptical properties of blends made of Poly(9,9-dioctyl-fluorene-2,7-diyl) (PFO) and Poly(3-hexylthiophene-2,5-diyl) (P3HT) were investigated and compared to those of Poly(9,9-dioctylfluorene-alt-bithiophene) (F8T2) by steady state optical spectroscopy. In addition to the individual emissions of PFO and P3HT chromophores, the blends composed by these two polymers show a new peak emission around 590 nm. The new peak is attributed to well dissolved, "isolated", P3HT chains dispersed into the PFO matrix. It was observed that the well dissolved P3HT chains are activated by Förster energy transfer, where PFO and P3HT molecules act as donor and acceptor, respectively. Further, emission from ordered aggregates of P3HT are clearly observed and the interplay between aggregate and isolate P3HT chains was studied. In contrast to the PFO:P3HT blends, the emission spectra from F8T2 co-polymer shows clear interaction in the ground state between the dioctylfluorene and bithiophene monomer-units, giving rise to a wholly new chromophore conformation on the backbone.

Magnetic properties of a polyfluorene derivative containing complexed neodymium ions

“…The red shift is so pronounced that the first peak at 370 nm completely disappears in concentrated conditions, whereas the one in the region centered at 390 nm attributed to the stacked chains is prominent in the whole spectra. This behavior is well documented in the literature . Additionally, the slow solvent evaporation during the sample preparation, together with the fact that the most favorable configuration of the terpyridine moiety in solution is the trans–trans, the closest to coplanar, are favorable conditions for the interchain stacking.…”

“…However, some drawbacks of those approaches still have to be overcome, mainly the poor solubility in common organic solvents, making it difficult the necessary film formation for the processing. To the best of our knowledge, the use of fluorene‐ derived copolymers was not yet explored as magnetic materials, especially when combined with appropriated sites for complexation with metallic ions, such as terpyridine. Additionally, these materials present important solubility properties in organic solvents, with ability of film formation by usual techniques, such as casting and jet printing and advantageous mechanical properties, turning them especially attractive for technological applications.…”

Effect of External Electric Field on Poly[(9,9-dioctylfluorenyl-2,7-diyl)-alt-co-(bithiophene)] Chain Orderness, Morphology, and Carrier Mobility in Different Condensation Processes

“…For the annealing and EEF treatment process, the changes in PL spectra were more sensitive than the absorption spectra, as shown in Figure . In Figure a, the as-cast film exhibited three emission peaks at 508, 538, and 576 nm, corresponding to the 0–0, 0–1, and 0–2 electronic transitions of F8T2, respectively. , According to the theory of Spano and co-workers, ,, in common polymer assembly, 0–0 transition in the PL spectrum is weakened because of its forbidden nature, but its abnormal dominant emission spectrum could be ascribed to the disorder of amorphous chains that reduce the total intrachain order (planarity) in the aggregate, which lead to the more allowed 0–0 transition. Therefore, the 0–0 intensity increase could indicate the increase of chain disorder; inversely, the 0–0 intensity reduction could indicate the increase of chain orderness.…”

What Is the Assembly Pathway of a Conjugated Polymer From Solution to Thin Films?

“…When dissolved in a good solvent mutual to both the conjugated backbone and the side chain, conjugated polymers are present in the form of dispersed polymer chains (McCulloch et al, 2013;Newbloom et al, 2015;Santos et al, 2016). Early works on poly(3hexylthiophene) (P3HT) have shown that the aggregation and crystallization of dispersed polymer chains can be commonly induced by lowering T (Samitsu et al, 2008;Koppe et al, 2009), decreasing the solvent quality (Park et al, 2009;Sun et al, 2011;Keum et al, 2013;Baghgar et al, 2014).…”