Goo Hwan Shim - Academia.edu (original) (raw)
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Papers by Goo Hwan Shim
Chemistry of Materials, 2006
In situ electrochemical methods involving both oxidative and reductive mediators were employed to... more In situ electrochemical methods involving both oxidative and reductive mediators were employed to modify the oxidation system (doping level) of PEDOT-coated silica core-shell particles that were prepared as a dispersion encapsulated in a hydrogel matrix.
Advanced Materials, 2005
NEXAFS measurements indicate complete conversion and optimal order. The highest mobilities (for t... more NEXAFS measurements indicate complete conversion and optimal order. The highest mobilities (for this work) are ob-served up to 250 C, even though the film is only slightly more than a monolayer thick by our quantification of surface cover-age. The large decrease in mobility at 300 C ...
Fibers and Polymers, 2004
Hydrolyzable organic esters were compared with ammonium sulphate as an acid donor for the pH cont... more Hydrolyzable organic esters were compared with ammonium sulphate as an acid donor for the pH control in dyebath-reuse system of acid dyes mixtures. The ability of pH control, levelness, dyeing properties and reproducibility in dyebath-reuse system were investigated comparatively. Hydrolyzable organic esters showed higher exhaustion and color yield than ammonium sulphate. In addition, hydrolyzable organic ester exhibited very low conductivity less than 0.5 mS, while ammonium sulphate give high conductivity. However, we could not observe any difference in levelness of dyed samples between two kinds of acid donors in laboratory scale dyeing. Over 10 cycles of reuse, hydrolyzable organic esters showed higher reproducibility than ammonium sulphate. No deterioration of the color fastness and levelness occurs over 10 cycles of reuse.
Journal of Materials Chemistry, 2008
Polyanline (PANI)-silica and poly(3,4-ethylenedioxythiophene) (PEDOT)-silica colloidal composite ... more Polyanline (PANI)-silica and poly(3,4-ethylenedioxythiophene) (PEDOT)-silica colloidal composite particles having a diameter of 200-300 nm were synthesized, then converted to intrinsically conducting polymer (ICP)-inks via solvent exchange. These inks could be inkjet-printed on indium tin oxide-coated poly(ethylene terephthalate) films (ITO-PET film) using a commercial desktop inkjet printer. These PANI-silica or PEDOT-silica/ITO-PET assemblies were utilized as the active layer in electrochromic devices (ECDs). A number of devices were fabricated that exhibited 500 mm size patterning and utilized spatially controlled printing of the particles to allow for a dual image display. In addition, the PANI and PEDOT-based particles were blended into a single ICP ink that allowed for a wider absorption tuning range of the final ECD.
Photonics and Nanostructures - Fundamentals and Applications
The attenuation of the reflected light from a polystyrene (PS) polymerized crystalline colloidal ... more The attenuation of the reflected light from a polystyrene (PS) polymerized crystalline colloidal array (PCCA) is achieved through the electrochemical switching of the electrochromic material polyaniline-poly(2-acrylamido-2-methyl-1-propanesulfonicacid) (PANI-PAMPS). For this purpose, layered electrochromic devices (ECDs) were fabricated that employed a PS PCCA film, acting as both a reflecting substrate and polymeric electrolyte, and the conducting polymer PANI-PAMPS, which served as the electrochromic layer. The resulting ECDs exhibited the attenuation of reflectance peak at the stop band position of the PCCA with a 3% of reflectance contrast ratio.
Chemistry of Materials, 2006
In situ electrochemical methods involving both oxidative and reductive mediators were employed to... more In situ electrochemical methods involving both oxidative and reductive mediators were employed to modify the oxidation system (doping level) of PEDOT-coated silica core-shell particles that were prepared as a dispersion encapsulated in a hydrogel matrix.
Advanced Materials, 2005
NEXAFS measurements indicate complete conversion and optimal order. The highest mobilities (for t... more NEXAFS measurements indicate complete conversion and optimal order. The highest mobilities (for this work) are ob-served up to 250 C, even though the film is only slightly more than a monolayer thick by our quantification of surface cover-age. The large decrease in mobility at 300 C ...
Fibers and Polymers, 2004
Hydrolyzable organic esters were compared with ammonium sulphate as an acid donor for the pH cont... more Hydrolyzable organic esters were compared with ammonium sulphate as an acid donor for the pH control in dyebath-reuse system of acid dyes mixtures. The ability of pH control, levelness, dyeing properties and reproducibility in dyebath-reuse system were investigated comparatively. Hydrolyzable organic esters showed higher exhaustion and color yield than ammonium sulphate. In addition, hydrolyzable organic ester exhibited very low conductivity less than 0.5 mS, while ammonium sulphate give high conductivity. However, we could not observe any difference in levelness of dyed samples between two kinds of acid donors in laboratory scale dyeing. Over 10 cycles of reuse, hydrolyzable organic esters showed higher reproducibility than ammonium sulphate. No deterioration of the color fastness and levelness occurs over 10 cycles of reuse.
Journal of Materials Chemistry, 2008
Polyanline (PANI)-silica and poly(3,4-ethylenedioxythiophene) (PEDOT)-silica colloidal composite ... more Polyanline (PANI)-silica and poly(3,4-ethylenedioxythiophene) (PEDOT)-silica colloidal composite particles having a diameter of 200-300 nm were synthesized, then converted to intrinsically conducting polymer (ICP)-inks via solvent exchange. These inks could be inkjet-printed on indium tin oxide-coated poly(ethylene terephthalate) films (ITO-PET film) using a commercial desktop inkjet printer. These PANI-silica or PEDOT-silica/ITO-PET assemblies were utilized as the active layer in electrochromic devices (ECDs). A number of devices were fabricated that exhibited 500 mm size patterning and utilized spatially controlled printing of the particles to allow for a dual image display. In addition, the PANI and PEDOT-based particles were blended into a single ICP ink that allowed for a wider absorption tuning range of the final ECD.
Photonics and Nanostructures - Fundamentals and Applications
The attenuation of the reflected light from a polystyrene (PS) polymerized crystalline colloidal ... more The attenuation of the reflected light from a polystyrene (PS) polymerized crystalline colloidal array (PCCA) is achieved through the electrochemical switching of the electrochromic material polyaniline-poly(2-acrylamido-2-methyl-1-propanesulfonicacid) (PANI-PAMPS). For this purpose, layered electrochromic devices (ECDs) were fabricated that employed a PS PCCA film, acting as both a reflecting substrate and polymeric electrolyte, and the conducting polymer PANI-PAMPS, which served as the electrochromic layer. The resulting ECDs exhibited the attenuation of reflectance peak at the stop band position of the PCCA with a 3% of reflectance contrast ratio.