• 한국정보디스플레이학회:학술대회논문집
• /
• 2007.08b
• /
• pp.1470-1473
• /
• 2007

We have demonstrated the optimization of white organic light-emitting diodes with two separated emissive layers using a blue fluorescent and a red phosphorescent dopant. The maximum luminous efficiency of the devices showed 7.93, 9.70, 11.8, and 14.3 cd/A. The $CIE_{xy}$ coordinates also showed (x = 0.33, y = 0.36), (x = 0.33, y = 0.35), (x =0.31, y = 0.35), and (x = 0.29, y = 0.36) at 6V, respectively.

• Textile Coloration and Finishing
• /
• v.29 no.1
• /
• pp.11-17
• /
• 2017

In this study, ozone oxidation experiment was carried out for the removal of fluorescent whitening agent which is widely used in textile dyeing and paper industry. The stilbene fluorescent whitening agent has been industrialized since the earliest, and the amount of current production is the highest. Due to the characteristics of the fluorescent whitening agent that can not be removed by conventional wastewater treatment methods, the fluorescent whitening agent in wastewater treatment has difficulty in using as recycled water in the process. Pre-treatment ozone oxidation experiment was conducted prior to the introduction of Membrane Bio Reactor(MBR) treatment process by converting biodegradable materials into biodegradable materials. The removal efficiencies of fluorescent whitening agents, a diaminostilbenedisulfonic acid derivative by ozone oxidation were evaluated by $UV_{254}$ Scan, $COD_{Mn}$, T-N and color using a synthetic wastewater sample ($COD_{Mn}=433.0mg/{\ell}$) and paper and paper mill wastewater ($COD_{Mn}=157.2mg/{\ell}$).

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.46 no.1
• /
• pp.11-17
• /
• 2014

This study analyzed the effects of specific factors on the fluorescence index of the fluorescent whitening agent (FWA) that is used for internal addition. The specific factors were identified by the literature review, and a statistical survey was carried out to analyze the effects of those factors on the fluorescence index. Bulk, grammage, fillers and internal sizing agents were selected as the specific factors. The paper samples were prepared with internal FWA in a laboratory. The fluorescence indices of the model papers were measured, and p-values of the specific factors on the fluorescence index were calculated by the SPSS program. Most of p-values were greater than 0.05, so the specific factors do not have a significant impact on the internal FWA fluorescence index.

• Transactions on Electrical and Electronic Materials
• /
• v.11 no.4
• /
• pp.186-189
• /
• 2010

Nano-sized MgO single crystal powders have recently been reported to emit ultraviolet by stimulation of electrons in a vacuum. In this study, nanocrystalline MgO powders were applied to a xenon plasma flat fluorescent lamp (FFL) for a liquid crystal display backlight to improve its emission efficiency through the extra ultraviolet from the nano-MgO crystals. For comparison, a MgO nano-thin film was applied directly on the phosphors inside a lamp panel through e-beam evaporation. Adding MgO nano-crystal powders to the phosphors improved the luminance and efficiency of FFLs by around 20% and MgO nano-crystal coverage of 40% of the phosphor provided the best FFL emission characteristics; however, application of MgO thin film to the phosphors degraded the emission characteristics, even compared to FFLs without MgO. This was due to insufficient ultraviolet stimulation of the phosphors and the crystallinity and low secondary electron coefficient of the MgO.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2006.08a
• /
• pp.1386-1389
• /
• 2006

In this study, a plasma flat fluorescent lamp having a new structure was fabricated by screen printing technique. Coplanar types of silver electrodes with a dielectric layer were screen-printed on a rear glass plate, and then fired at $550^{\circ}C$ and $580^{\circ}C$, respectively. Phosphor was spin-coated on the dielectric layer with firing at $490^{\circ}C$. Several types of lamps were designed and its properties wee investigated with electrode shape, gas pressure, etc.

• Proceedings of the Polymer Society of Korea Conference
• /
• 2006.10a
• /
• pp.193-193
• /
• 2006

Fluorescent dyes were encapsulated in the nanometer-sized diblock copolymer micelles to control the fluorescence resonance energy transfer. Since acceptor molecules and donor molecules were effectively isolated in the independent micelles, the energy transfer between donors and acceptors was suppressed by the site isolation, leading to the simultaneous emission from both donor and acceptor molecules.

• Bulletin of the Korean Chemical Society
• /
• v.32 no.5
• /
• pp.1593-1598
• /
• 2011

Blue fluorescent materials based on 9,9'-diethyl-2-diphenylaminofluorene derivatives were synthesized and characterized. These materials were used as the blue dopant materials for the emitting layer of organic light-emitting diode devices with the following device structure: ITO/DNTPD (40 nm)/NPB (20 nm)/MADN: dopants (2%, 20 nm)/$Alq_3$ (40 nm)/Liq (1.0 nm)/Al. All devices exhibited highly efficient blue emission. One of these devices exhibited a maximum luminance, luminous efficiency, power efficiency and CIE x, y coordinates of 8400 $cd/m^2$, 8.10 cd/A at 20 $mA/cm^2$, 3.36 lm/W at 20 $mA/cm^2$ and (0.151, 0.159), respectively. A deep blue device with CIE coordinates of (0.152, 0.139) showed the maximum luminance, luminous efficiency and power efficiency of 8630 $cd/m^2$, 6.31 cd/A at 20$mA/cm^2$ and 2.62 lm/W at 20 $mA/cm^2$, respectively.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2009.10a
• /
• pp.687-690
• /
• 2009

It has been recently reported that nano-sized MgO single crystal powders emit ultraviolet by stimulation of electrons under vacuum condition. Therefore, in this study, nano-crystalline MgO powders were applied to a xenon plasma flat fluorescent lamp for LCD backlight to improve emission efficiency of the lamp by help of extra ultraviolet from nano-MgO. For comparison with nano-crystalline MgO powders, MgO nano-thin film was applied directly on phosphors inside a lamp panel through e-beam evaporation The luminance and efficiency of FFL with an addition of MgO nano-crystal powders on phosphors were improved by around 20%. Application of MgO thin film to phosphors worsened the emission characteristics of FFLs, even rather than FFL without MgO. The reason came from insufficient stimulation of phosphors by UV, crystallinity of MgO, and low secondary electron coefficient.

• Proceedings of the Materials Research Society of Korea Conference
• /
• 1998.11a
• /
• pp.130-130
• /
• 1998

• Proceedings of the Korean Fiber Society Conference
• /
• 2003.10a
• /
• pp.23-24
• /
• 2003

We synthesized a poly[2-(2'-hydroxyphenyl) benzoxazole] under the two step procedures of Suzuki coupling polymerization with corresponding monomers followed by the deprotection of benzyl group. The polymer in DMF solution is applicable to colorimetric sensing fluoride anion, which shows a color change from colorless to yellow. High sensitivity to fluoride anion compared to other anions such as phosphate, chloride, and sulfate is ascribed to the high coordination ability of the 2-(2'-hydroxy phenyl)benzoxazole moiety in the polymer chain. Emission shift by metal cations, which can be applied to fluorescent sensing w as also observed in the polymer solution.