• Bulletin of the Korean Chemical Society
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• v.33 no.11
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• pp.3593-3596
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• 2012

The water-soluble conjugated polymer with fluorescence quenching as a result of electrostatic interaction and aggregation was synthesized through Suzuki polymerization. The absorption and emission of anionic polymer (a-PFP) is blue shifted as compared with cationic polymer (c-PFP) although getting same backbone, and the absolute PL quantum efficiency of a-PFP in water is over 90% due to good solubility in aqueous solution. We anticipate that the fluorescence quenching of anionic and cationic polymers, with same conjugated backbone, could be shown in aqueous solution.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.103.1-103.1
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• 2014

Due to their excellent optical and electrochemical properties, conjugated polymers have attracted much attention over the last two decades and employed to opto-electrical devices. In particular, conjugated polymers possess many attractive features that make them suitable for a variety of sensing task. For example, their delocalized electronic structures can be strongly modified by varying the surrounding environment, which significantly affected molecular energy level. In other word, conjugated polymers can detect and transduce the environmental information into a fluorescence signal. Conjugated polymers also display amplified quenching compared to small molecule counterparts. This amplified fluorescence quenching is attributed to the delocalization and migration of the excitons along the conjugated polymer backbones. Long backbones of conjugated polymer provide the transporting path for electron as a conduit, allowing that excitons migrate rapidly into quencher site along the backbone. This is often referred to as the molecular wire effect or antenna effect. Moreover, structures of conjugated polymers can be easily tailored to adjust solubility, absorption/emission properties, and regulation of electron/energy transfer. Based on this versatility, conjugated polymers have been utilized to many novel sensory platforms as a promising material. In this tutorial, I will highlight a variety of fluorescence sensors base on conjugated polymer and explain their sensory mechanism together with selected examples from reference literatures.

• Bulletin of the Korean Chemical Society
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• v.34 no.11
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• pp.3340-3344
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• 2013

The fabrication of polymer field-effect transistors with good electrical properties requires the minimization of molecular defects caused by low molecular weight (MW) fractions of a conjugated polymer. Here we report that the electrical properties of a narrow bandgap conjugated polymer could be dramatically improved as a result of dipping a thin film into a poor solvent. The dipping time in hexanes was controlled to efficiently eliminate the low molecular weight fractions and concomitantly improve the molecular ordering of the conjugated polymer. The correlation between the structural order and the electrical properties was used to optimize the dipping time and investigate the effects of the low MW fraction on the electrical properties of the resulting thin film.

• Macromolecular Research
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• v.13 no.6
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• pp.491-498
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• 2005

Fluorene-containing, spiro-type, conjugated polymers were synthesized via the cyclopolymerization of dipropargylfluorenes (2-substituted, X=H, Br, Ac, $ NO_{2}$) with various transition metal catalysts. The polymerization of dipropargylfluorenes proceeded well using Mo-based catalysts to give a high polymer yield. The catalytic activities of the Mo-based catalysts were found to be more effective than those of W-based catalysts. The palladium (II) chloride also increased the polymer yield of the polymerization. The polymer structure of poly(dipropargylfluorene)s was characterized by such instrumental methods as NMR ($^{1}H_{-}$, $^{13}C_{-}$), IR, UV-visible spectroscopies, and elemental analysis as having the conjugated polymer backbone bearing fluorene moieties. The $^{13}C_{-}$NMR spectral data on the quaternary carbon atoms in polymers indicated that the conjugated cyclopolymers have the six-membered rings majorly. The poly(dipropargylfluorene) derivatives were completely soluble in halogenated and aromatic hydrocarbons such as methylene chloride, chloroform, benzene, toluene, and chlorobenzene. The poly(dipropargylfluorene) derivatives were thermally more stable than poly(dipropargylfluorene) itself, and X-ray diffraction analyses revealed that the polymers are mostly amorphous. The photoluminescence peaks of the polymers were observed at about 457-491 nm, depending on the substituents of fluorene moieties.

• Applied Chemistry for Engineering
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• v.31 no.5
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• pp.467-474
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• 2020

Polymer solar cells have attracted extensive attention over the past decade due to their benefits, such as good solution-process-ability, light weight, low-cost, mechanically flexibility, and high efficiency. Conjugated (CPE) and non-conjugated (NPE) polyelectrolyte materials have been employed to avoid the typical weaknesses associated with conventional metal oxide interlayers. However, the application of CPEs is more complicated than that of NPEs because the synthesis procedures are complicated. NPEs containing charged ion groups can provide numerous benefits for renewable energy applications. Especially when implemented in polymer solar cells.

• Journal of Adhesion and Interface
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• v.24 no.1
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• pp.1-8
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• 2023

A conjugated polymer is the next-generation emerging semiconductor material that can be applied in various fields, from organic electronics to biomedical applications. However, its low solubility in an aqueous medium has made the use of toxic organic solvents inevitable, thereby leading to formulation of conjugated polymers in the form of waterborne nanoparticles. This review paper discusses two principles of nanoparticle formation and representative methods for synthesizing conjugated polymer nanoparticles.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.19-20
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• 2006

We report the design of electroluminescent conjugated polymers for high efficiency, turn-on voltage, color Tuning, and easy processing. Three approaches for the design are reported, being: (1) single chain consideration, (2) supramolecular structure consideration, and (3) conformation manipulation. Two polymer systems are to be reported, being fluorene-based and carbazole-based conjugated polymers.

• Bulletin of the Korean Chemical Society
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• v.30 no.12
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• pp.3025-3030
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• 2009

Novel poly(aspartic acid) derivatives conjugated with $\gamma$-amino butyric acid, GABA, moieties, and their amphiphilic analogs were synthesized and characterized. The chemical structures of these polymers were confirmed by FT-IR and $^1H$ NMR spectroscopy. Their physicochemical properties in aqueous media were characterized by electrophonetic light scattering spectrophotometry (ELS), acid-base titration, and UV-spectroscopy. In addition, the in vitro cell activity of the GABA-conjugated polymer was examined. These results indicated that GABA-conjugated poly(aspartic acid) derivatives showed cell-growth activity and nanoparticle formation of a suitable size within aqueous media. These polymers have potential application in the cosmetic and pharmaceutical fields.

• Bulletin of the Korean Chemical Society
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• v.25 no.6
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• pp.777-778
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• 2004

• Journal of Information Display
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• v.2 no.2
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• pp.45-51
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• 2001

Four types of conjugated polymers, poly(MEHPV-PV), poly(MEHPV-BPV), poly(MEHPV-AV) and poly(PZV-AV) were synthesized by Homer-Emmons reaction using potassium tert-butoxide. The Homer-Emmons reaction gave electroluminescent(EL) copolymers in good yield. Of the EL copolymers synthesized, poly(PZV-AV) containing phenothiazinylene vinylene and anthrylene vinylene as repeat unit exhibited red color in the light emitting diode(LED) which was very close to the NTSC standard red. Besides, double layer LED made with $Alq_3$ electron transport layer exhibited both enhanced emission intensity and efficiency compared to the single layer LED.