Browsing by Author "Dinakaran, K"

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Synthesis and characterization of an efficiently fluorescent poly(phenylenevinylene) possessing pendant dendritic phenyl groups
(2005-12-13)
Dinakaran, K
;
Hsiao, SM
;
Chou, CH
;
Shu, SL
;
Wei, KH
We have synthesized a thermally stable and high molecular weight fluorescent poly(phenylenevinylene) (PPV) incorporating side-chain-tethered dendritic phenyl groups (DENPPV) through Gilch route; this DENPPV has a low abundance of tolane-bisbenzyl defects. Intramolecular energy transfer from the dendritic phenyl side group to the PPV backbone was evidenced from UV-vis and photoluminescence spectra of the DENPPV polymer and its model compound. Copolymers of DENPPV with 2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene (MEHPPV) display excellent photoluminescence both in solution and in the solid state; the highest quantum yield we observed was 82%. The electroluminescence of the copolymer MEHPPV/DENPPV (molar ratio: 25/75) was 70% higher than that of MEHPPV (0.12 lm/W vs 0.07).
Synthesis and characterization of fluorescent poly [fluorene-co-phenylene-1-(di-2-pyridylamine)] copolymer and its Ru(II) complex
(2004-10-01)
Dinakaran, K
;
Chou, CH
;
Hsu, SL
;
Wei, KH
;
材料科學與工程學系
2,2'-dipyridylamine substituted poly(fluorene-co-phenylene) copolymers with different concentrations of dipyridylamine have been synthesized by Suzuki polycondensation. These polymers were found to be soluble in organic solvents such as tetrahydrofuran, chloroform, and dimethylformamide. The photoluminescence of the copolymer was slightly blueshifted as the concentration of dipridylamine was increased. The introduction of dipyridylamine and the ruthenium complex into the polymer significantly improved the photoluminescence efficiency. (C) 2004 Wiley Periodicals, Inc.
Synthesis and characterization of luminescent polyfluorenes incorporating side-chain-tethered polyhedral oligomeric silsesquioxane units
(2005-02-08)
Chou, CH
;
Hsu, SL
;
Dinakaran, K
;
Chiu, MY
;
Wei, KH
Using Suzuki polycondensation, we have synthesized polyhedral silsesquioxane-tethered polyfluorene copolymers, poly(9,9'-dioctylfluorene-co-9,9'-bis[4-(N,N-dipolysilsesquioxane)aminophenyl]fluorene) (PFO-POSS), that have well-defined architectures. This particular PFO-POSS molecular architecture increases the quantum yield of polyfluorene significantly by reducing the degree of interchain aggregation; in addition, these copolymers exhibit a purer and stronger blue light by preventing the formation of keto defects.