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Synthesis and electro-optical properties of fluorene containing blue luminescent rod-coil homopolymers with pendant pyridine

Sahu D., Chakroborty S.

Materials Science Poland

2017

Vol. 35, No. 1

217--224

Two well defined, blue luminescent homopolymers containing 9,9-diethylfluorene core with electron withdrawing pendant pyridine, Suzuki-coupled with the corresponding borolane of decoxy phenyl (PFPA) and naphthalene (PFNA) have been designed and synthesized efficiently. The obtained rod-coil polymers have the average molecular weight of 15212 (PFPA) and 15130 (PFNA) with polydispersity indices (PDIs) 1.07 and 1.3, respectively. The polymers have good solubility and high thermal stability with the decomposition temperature of 362 °C (PFPA) and 367 °C (PFNA) correspondingly. Furthermore the optical and electrochemical properties of the polymers have been investigated. The polymers exhibited photoluminescence (PL) maxima at 410 nm (PFPA) and 414 nm (PFNA) excited at 340 nm, as stable blue luminescence polymers at low concentration of 10−6 M with a quantum yield of 0.64 and 0.62, respectively. In addition the annealed (150 °C) polymer films showed better stability of its photoluminescence spectra. Absorbance and fluorescence emission spectra of PFPA and PFNA were compared in order to evaluate the effects of substituent, phenyl and naphthalene in pyridine pendant fluorene moieties.

Active glasses as the luminescent sources of radiation for sensor applications

Żmojda J., Dorosz D., Kochanowicz M., Dorosz J.

Bulletin of the Polish Academy of Sciences. Technical Sciences

2014

Vol. 62, nr 2

393--397

The article presents physicochemical, thermal and spectroscopic properties of two different glass systems: TeO2-GeO2-PbO-PbF2- BaO-Nb2O5-LaF3 and SiO2-Al2O3-Sb2O3, co-doped with Yb3+/Tm3+ ions. Blue upconversion luminescence at a wavelength of 478 nm corresponding to the thulium 1G4 ⇥3H6 transition was observed under 976 nm pump radiation in both of the co-doped glasses. This indicated the existence of efficient Yb3+ ⇥ Tm3+ energy transfer via three-photon absorption mechanism. Thermal and optical results substantiate the claim for practical applicability of the manufactured glasses in design of optical fiber sources.