Synthesis, photophysical properties and thermal relaxation processes of carbazolyl-labeled polysiloxanes

Domingues, Raquel Aparecida; Yoshida, Inez Valéria Pagotto; Atvars, Teresa Dib Zambon

doi:10.1016/j.jphotochem.2010.11.003

Cited by 11 publications

(14 citation statements)

References 29 publications

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“…PVK absorbs in the UV range and emits from 350 to 500 nm (λ exc = 290 nm) as a broader band. This emission is very characteristic of the PVK excimers (peak at 372 nm with a longer red‐edge tail; 27–35). The shoulder in the PL spectrum at approximately 340 nm may be ascribed to the isolated lumophores.…”

Section: Resultsmentioning

confidence: 97%

“…The steady-state emission of the isolated carbazolyl groups is observed as a shoulder in the blue-edge of the emission band centered at k em = 400 nm; thus, the component with s F1 = 1.83 ns may be attributed to the carbazolyl groups undergoing quenching due to their proximity to longer sequences of carbazolyl moieties. The slower component may be attributed to excimer emission (28)(29)(30)(31)(32)(33)(34)(35). Figure 2 also shows a strong overlap between the PL spectrum of the PVK and PFO-MEHPV electronic absorption spectra, suggesting that mixtures of these two materials may undergo either FRET or trivial energy transfer from PVK to the polyfluorene.…”

Section: Methodsmentioning

confidence: 97%

“…Poly(vinyl carbazole) has very complex intrinsic photophysical pathways after electronic photoexcitation that competes with the energy transfer process to an extrinsic acceptor (28)(29)(30)(31)(32)(33)(34)(35)(36). Some of these pathways are related to the presence of intrachain trapping centers, such as the excimer-forming traps (27)(28)(29)(30)(31)(32)(33)(34)(35). When the monomer-like emission (singlet excitons) is absent, as observed in the present system, the energy migration from the excited state monomer units toward the excimer-like trap is very efficient.…”

Section: Energy Transfer In Solutionsmentioning

confidence: 99%

See 2 more Smart Citations

Energy Transfer from Poly(Vinyl Carbazole) to a Fluorene‐Vinylene Copolymer in Solution and in the Solid State^†

Bonon¹,

Atvars²

2012

Photochem & Photobiology

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This article reports a comparative study of the energy transfer processes in solution and the solid state from poly(vinyl carbazole; the donor) to dimethylphenyl-terminated poly[(9,9-dioctylfluorenyl-2,7-divinylene-fluorene)-co-alt-{2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylene}] (the acceptor). The results in solutions suggest that a decrease of the donor emission intensity with an increasing acceptor concentration is more closely related to the trivial energy transfer process, indicating that the donor and acceptor chains are not in close contact during the lifetime of the donor excited state. This conclusion was reached using the amplitude-averaged lifetime of the donor, which is practically independent of the acceptor concentration. In the solid state, the polymer blends showed a decrease in the donor emission with an increasing acceptor concentration, and a decrease in the donor lifetime was also observed. Thus, in the solid state, changes in morphology interfere with the nonradiative resonant energy transfer process, but influence on the trivial process cannot be completely neglected. The lifetime does not follow a continuous decrease with the PFO-MEHPV concentration like the emission intensity does. The changes in the lifetime values occur over the same concentration range as do the changes of morphology, as shown by the scanning electron micrographs.

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Section: Resultsmentioning

confidence: 97%

Section: Methodsmentioning

confidence: 97%

Section: Energy Transfer In Solutionsmentioning

confidence: 99%

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Energy Transfer from Poly(Vinyl Carbazole) to a Fluorene‐Vinylene Copolymer in Solution and in the Solid State^†

Bonon¹,

Atvars²

2012

Photochem & Photobiology

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“…In addition, a weak emission band centered at 468 nm was also observed for all the elastomeric systems analyzed. Literature findings reveal that such band can be related to the phosphorescent emission of the carbazole units …”

Section: Resultsmentioning

confidence: 99%

Optical Mechanotransduction with Carbazole‐Based Luminescent Liquid Single‐Crystal Elastomers

García-Amorós

Velasco

2015

Macromol. Rapid Commun.

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Carbazole-based liquid single-crystal elastomers (LSCEs) are valuable fluorescent flexible materials to perform optical mechanotransduction under ambient conditions. Indeed, the covalent incorporation of carbazole derivatives into nematic LSCEs allows to tune their luminescence on demand under mechanical control in a quick and reversible fashion. Specifically, the fluorescence intensity for these materials can be switched back and forth in less than a second. Moreover, such a process can be performed several times without detecting any sign of fatigue in the system. In addition, these materials show excellent resistance to aging; 2 years after their preparation they exhibit the very same mechanofluorescent behavior as when freshly prepared. In fact, the here reported fluorescent systems are highly sensitive; the application of a force of 70 mN decreases the fluorescence in the elastomeric material by 7%. Thus, mechanical forces are attractive external stimuli to modulate the fluorescence of nematic elastomers rapidly and reversibly enabling thereby mechanotransduction.

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“…Macromolecules end-capped carbazole moieties were also used as luminescent films electrodeposited (ED) with good electropolymerization behaviors and properties [10]. Likewise, polymers bearing carbazole structure has been widely described [14][15][16][17][18][19], e.g., fluorescent carbazolyl-labeled polysiloxanes [14]. A green light-emitting phosphorescent and polymeric light-emitting diode (PLED), containing a layer of a carbazole-oxadiazole copolymer showed a high efficiency, current densities, and luminance levels [15].…”

Section: Introductionmentioning

confidence: 99%

Novel concept of polymers preparation with high photoluminescent quantum yield

et al. 2016

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A series carbazolyl-containing polymers were synthesized by anionic polymerization of various oxiranes and methyl methacrylate. The polymerization was carried out using as initiator carbazylpotassium activated 18-crown-6 in THF. The polymers were prepared and found using size exclusion chromatography to have a degree of polymerization (DP n ) about 20 relatively and low dispersity in the range of 1.07-1.66. Their optical properties were investigated by means of UV-vis and photoluminescence spectroscopies. The obtained polymers emitted light with maximum emission about 370 nm and high quantum yield ranging up to 79 %. Thus, it was confirmed that the utilization of fluorophore initiator for polymerization of non photoresponsive monomers is quite efficient for the preparation of photoluminescent polymers.

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Synthesis, photophysical properties and thermal relaxation processes of carbazolyl-labeled polysiloxanes

Cited by 11 publications

References 29 publications

Energy Transfer from Poly(Vinyl Carbazole) to a Fluorene‐Vinylene Copolymer in Solution and in the Solid State^†

Energy Transfer from Poly(Vinyl Carbazole) to a Fluorene‐Vinylene Copolymer in Solution and in the Solid State^†

Optical Mechanotransduction with Carbazole‐Based Luminescent Liquid Single‐Crystal Elastomers

Novel concept of polymers preparation with high photoluminescent quantum yield

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Synthesis, photophysical properties and thermal relaxation processes of carbazolyl-labeled polysiloxanes

Cited by 11 publications

References 29 publications

Energy Transfer from Poly(Vinyl Carbazole) to a Fluorene‐Vinylene Copolymer in Solution and in the Solid State†

Energy Transfer from Poly(Vinyl Carbazole) to a Fluorene‐Vinylene Copolymer in Solution and in the Solid State†

Optical Mechanotransduction with Carbazole‐Based Luminescent Liquid Single‐Crystal Elastomers

Novel concept of polymers preparation with high photoluminescent quantum yield

Contact Info

Product

Resources

About

Energy Transfer from Poly(Vinyl Carbazole) to a Fluorene‐Vinylene Copolymer in Solution and in the Solid State^†

Energy Transfer from Poly(Vinyl Carbazole) to a Fluorene‐Vinylene Copolymer in Solution and in the Solid State^†