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Electrochemical fluorescence switching of electroactive fluorescent anthracene polymer films was studied using an electro active quencher. The fluorescence of a methylene anthracene polymer (PMAn) was intact under redox reaction in the absence of an electroactive quencher. Interestingly the fluorescence of a methylene bridged anthracene polymer (PMAn) film could be modulated by adjusting the redox state of the PMAn and redox reaction of the quencher. The electrochemical fluorescence switching from the PMAn film with a quencher was reversible and the cyclability was longer than 1,000 cycles with an ON/OFF ratio of 3.86 under the applied potential step of +2 V for 4 second. A multi state fluorescent switch was fabricated with a double layered two electrode cell that was consisting of the PMAn layer doped with a quencher and a solid polymer electrolyte layer (SPE). [ABSTRACT FROM AUTHOR]

Multi-color electrochromic (EC) device was fabricated on a patterned ITO glass. Organic electrochromic dyes were encapsulated within nano-sized porous TiO2 nanoparticles, and their relative electrochromic (EC) properties were determined using spectroelectrochemical method. Blue, green, and red colored organic dye doped TiO2 nanoparticles were coated on a patterned ITO substrate to afford multi-colored EC electrode, which was coated with a photo-curable polymer electrolyte and then covered with a bare ITO glass as a counter electrode. Upon photocuring of the electrolyte layer under UV light, an all-solid state multi-colored electrochromic device (ECD) was obtained. The resultant ECD showed reversible multi-color change within 8 sec and high optical contrast. [ABSTRACT FROM AUTHOR]

Photopolymer films were prepared for holographic recording and fabrication of multi-dimensional holographic fluorescent patterns. The photopolymer consists of a methacrylate epoxy monomer, photoinitiator, sensitizer, binder polymer, and polyanthracene (PAnt) as a fluorophore. The high diffraction efficiency of fluorescent photopolymer film was determined through a holographic recording system as 60% for a film of 85 µm in thickness. The optimized photopolymer film was applied to fabricate 2 dimensional patterns by laser interference lithography technique and rotation method. A 2-dimensional pattern was confirmed from a fluorescent microscope, which showed crossed pattern having a line width of 0.7 μm. [ABSTRACT FROM AUTHOR]

A fluorescence switching property of a copolymer of piperidinyl s-triazine (PT) and p-(trimethylsilyl) phenylene vinylene (TPV) was investigated by utilizing redox reaction of electroactive iodides. A polymer having high fluorescence quantum yield was synthesized by Wittig polycondensation reaction with 4, 6-bis (4-formylphenoxy)-2-piperidinyl-s-triazine and 2, 5-bis (triphenylphosphonionmethyl)-1, 4-bis (trimethylsilyl) benzene dibromide, to make a copolymer of PT and TPV (PTTPV). The fluorescence of the polymer was easily modulated by external potential in a two electrode cell consisting fluorescent layer and polymer electrolyte layer. When the fluorescent polymer layer was doped with iodide ions, the cell showed reversible switching property by applied potentials within±3 V. [ABSTRACT FROM AUTHOR]

A highly fluorescent s-triazine (ST) bridged p-phenylene vinylene (PPV) polymer was synthesized by the Wittig polycondensation reaction of 4, 6-bis (4-formylphenoxy)-2-diphenylamino-s-triazine and 2, 5-bis (triphenylphosphonionmethyl)-1, 4-bis (trimethylsilyl) benzene dibromide, to afford ST bridged PPV polymer (DTTPV). The fluorescence of the polymer was dramatically changed by the application of the external potential from - 2 V to 2 V in a two electrode cell containing a solid polymer electrolyte layer. The fluorescence switching was reversible with a switching time of 4s. [ABSTRACT FROM AUTHOR]

An alkylsulfonated polyaniline, poly(aniline-N-butylsulfonate)s (PANBS), was assembled by the layer-by-layer (LBL) assembling technique as an electroactive anionic polymers for the layering. The counter ions for PANBS layer were polyaniline (H + doped) and vinylbenzyldimethyl-n-alkylammonium salts (VBAA) as the conductive and insulating polycation, respectively. High color contrast was observed when the electrochromic (EC) film was composed alternatively of the PANBS/PAN and PANBS/VBAA layer. Interlayer insulating gap controlled by the alkyl chain length of VBAA, was an important factor to increase EC response of the window assembled by the LBL method. [ABSTRACT FROM AUTHOR]

The combination of photochromism and electrical properties in diarylethene (DA) polymers were investigated. Photoswitching function could be introduced into a polymer by incorporating 2,3-bis(2-methylbenzo[b]thiophene-3-yl)hexafluorocyclopentene (BTF) unit plus p-phenylene vinylene (PPV) unit alternatively. The photochromic film of BTF-PPV polymer become dark colored upon exposure to a UV light because p-conjugation delocalizes between the p-conjugative groups and the new absorption band centered at 570 nm was observed from the colored film. In dark the photochromic electrode coated with BTF-PPV copolymer did not show current generation. Upon exposure to UV, large incident photon-to-current generation was observed with the quinone/hydroquinone carrier couple under a bias potential of 165 mV (vs. Ag/AgCl). By optical modulation, a reversible photocurrent generation was observed from the photochromic electrode. On the otherhands, DA polymers derived from 2,3-bis(2-methyl-3-thienyl)hexafluorocyclopentene (TF) and PPV showed no photocurrent generation, indicating photodecomposition of the closed isomer. [ABSTRACT FROM AUTHOR]

We synthesized 3′,3′-dimethyl-1′-octadecyl-6-nitrospiro-[2H-1-benzopyran-2,2′-indoline] (SP-18) and examined its photochromic behavior and fluorescence in the presence of acid. When strong acids such as HCl and dodecylbenzenesulfonic acid (DBSA) were present, the merocyanine (MC) form generated via heterolytic cleavage of oxygen-carbon bond of the spiropyran (SP) by the irradiation of UV light was protonated to produce the complex MCH + . The MCH + had a yellow color with the absorption maxima at between 410∼430 nm. Since ring-closing reaction of the MC form to produce the SP form was retarded by the protonation of the phenolate in the MC form, MCH + had better stability than the MC. Emission peak of the MCH + form was observed at 645 nm with HCl and 600 nm with DBSA, respectively. Polymethylmethacrylate (PMMA) films containing the MCH + retained about 75% of its original absorbance even after 48 h. [ABSTRACT FROM AUTHOR]