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 Research Overview |
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Rotaxane & Polymeric Rotaxane: Self-assemlied Supramolecules The purpose of this study is to provide novel supramolecular complexes formed from organic colorants and cyclodextrins. For this purpose, we intend to synthesize various azo dyes and conductive polymers and then form their rotaxane and pseudo-rotaxane in the presence of cyclodextrins. Numerous characterization techniques will be involved in order to identify the final sturcture of the inclusion complexes. We also demonstrate to generate nanofibers and nanowebs with different morphologies by electrospinning, adsorption/attachment, and inkjet printing method. Another goal of this study is to present new promising applications which will include chemical sensor, dye sensitized solar cells, and electronic polymers and fibers.
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Conjugated Polymers and their Organic-Inorganic Hybrids We have synthesized various conjugated polymers based on poly(p-phenyleneethynylene)s (PPEs hereafter). One examples includes polyester grafted poly(p-phenyleneethynylene)s (PET-g-PPEs), which was prepared utilizing acetylene gas in a Pd-catalyzed process. Their optical properties have been examined with the length of grafted side-chain. Nanostructured fiber can be fabricated by electrospinning, and large surface area are uniformly covered by this method. It has been noticed that side chain length, concentration, and solvent polarity determined the resulting morphology. When, especially, electrospun into liquid nitrogen, unique nanoporous structure emerged. Furthermore, we encapsulate PET side- chain in the presence of various macrocycles by forming inclusion complexes, and estimate the morphological changes by the encapsulation. The purpose of this study is to investigate the optical property, and melting and crystallization behaviors of grafted PPEs by numerous characterization techniques, including photoluminescence, differential scanning colorimeter, polarized optical microscope, and laser scanning confocal microscope. We also intend to explore possible applications of fascinating conjugated polymers of such kind. Recently, we are under the preparation of new graft & block copolymers of PPEs and their hybrids, which will find interesting applications for molecular sensing, metal/bio-sensing, phototransistors, organic electrocnics, etc. Details will be updated in the future.
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Display Materials and their Micro-patternings The fabrication of flat panel displays (FPDs), such as thin film transistor liquid crystal displays (TFT LCDs), have mostly involved expensive photolithographic (PL) process. With the continuing drive to reduce their manufacturing cost, alternative methods have been suggested, among which various printing techniques were introduced, including inkjet printing, gravure offset , and microcontact printing. In this study, we analyze the factors affecting optical property of FPDs as a measure to understand the conditions under which more desirable properties can be achieved. We also synthesize new polymeric materials which helps develop uniform and desirable surface characteristics. We also utilize and apply more sophisticated analytical tools such as secondary ion mass spectrometry (SIMS) technique to provide optimum condition for solution processing. |
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Solution-Processable Organic Electronics In this study we intend to fabricate OTFTs by inkjet printing. For this, optimum material properties and their jetting conditions have been examined. We estimate TFT performance and compare with one fabticated by conventional lithography.
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Selected Publications |
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Patents |
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