New light‐emitting poly{(9,9‐di‐n‐octylfluorenediyl vinylene)‐alt‐[1,5‐(2,6‐dioctyloxy)naphthalene vinylene]}

A new conjugated light‐emitting AB copolymer containing alternating fluorene and naphthalene units, poly{(9,9‐di‐n‐octylfluorenediyl vinylene)‐alt‐[1,5‐(2,6‐dioctyloxy)naphthalene vinylene]} (PFV‐alt‐PNV), was synthesized via Horner‐Emmons polymerization. The polymer is completely soluble in common organic solvents and exhibits good thermal stability up to 400 °C. UV‐visible, fluorescence and photoluminescence measurements of the copolymer show peak maxima at 427, 500 and 526 nm, respectively. A light‐emitting device containing the new polymer was fabricated using a simple indium tin oxide configuration: (ITO)/PEDOT:PSS/PFV‐alt‐PNV/Al. Measurements of current versus electric field were carried out, with an onset of light emission occurring at 2.5 V. The electroluminescence brightness was observed to reach a maximum of 5000 cd m^?2. Copyright © 2011 Society of Chemical Industry     

Defect-free Poly(9,9-bis(2-ethylhexyl)fluorene-2,7-vinylene) for Polymer Light-Emitting Diode (PLED) Devices

The π-conjugated light-emitting polymer poly(9,9-bis(2-ethylhexyl)fluorene-2,7-vinylene) (PEHFV), was synthesized in defect-free form via Horner-Emmons coupling. The structure and properties of the polymer were characterized by ¹H NMR, ¹³C NMR, UV-vis, photoluminescence (PL), and electroluminescence (EL) spectroscopies as well as gel permeation chromatography (GPC) and thermogravimetric analysis (TGA). The weight-average molecular weight (M_w) and polydispersity of the PEHFV were 34,000 g/mol and 2.3, respectively. The UV-vis spectra showed absorption maxima at 425 and 452 nm, and the PL emission spectra showed a maximum at 505 nm with a shoulder at 541 nm. The polymer was soluble in common organic solvents and easily spin-coated on indium-tin oxide (ITO)-coated glass substrates. A double-layer light-emitting device with an ITO/PEDOT:PSS/PFV/Al configuration was fabricated. The turn-on voltage for the PEHFV device was observed at 3.0 V.     

Characterization of Hydrothermally Synthesized PLZT for Pyroelectric Applications

PLZT fine powders have been synthesized by a hydrothermal process using lead acetate, lanthanum acetate, zirconium n-propoxide and titanium isopropoxide as starting materials. The synthesis was performed at 200°C for 8, 12 and 24 h. 4 M KOH was used as a mineralizer to adjust the pH to an optimum value for the mixed precursor solution. After hydrothermal treatment the solid portion was separated out, washed and dried at 100°C for 12 h, where PLZT fine powders were obtained. PLZT powders were characterized using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The PLZT powders were pressed and sintered to obtain high density ceramics, which then were investigated by XRD and SEM. The dielectric properties of the ceramics were investigated by measurements of dielectric constant and dielectric loss as a function of temperature at a fixed frequency.     

Synthesis and characterization of poly(2,5‐didecyl‐1,4‐phenylene vinylene), poly(2,5‐didecyloxy‐1,4‐phenylene vinylene), and their alternating copolymer

The preparation of dialkyl‐substituted poly(2,5‐didecyl‐1,4‐phenylene vinylene) ( PDDPV ) by the Horner‐Emmons polycondensation is described. Its performance in an organic light‐emitting diode (OLED) device architecture is compared with devices prepared from the analogous dialkoxy‐substituted poly(2,5‐didecyloxy‐1,4‐phenylene vinylene) ( PDOPV ) and the corresponding alkyl‐alkoxy‐substituted alternating copolymer. Additionally, the structure, stability, electrochemical, and optical properties of the PPVs were characterized by gel permeation chromatography, thermogravimetric analysis, NMR spectroscopy, cyclic voltammetry, UV‐Visible spectroscopy, and fluorescence spectroscopy. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 41162.