• Journal of the Korean Chemical Society
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• v.55 no.2
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• pp.279-282
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• 2011

Dye-sensitized solar cell (DSSC); an alternate energy source harvester has gained some attractive features such as high-energy conversion efficiency low production cost. Dye-sensitizer is a basic component of DSSC, which affecting the performance of the energy conversion efficiency. Current research has been focusing on development of high efficiency, metal-free dye-sensitizers, which would be more environmental friendly. We had successfully explored synthetic route to 6,6'-(1,2,5-oxadiazole-3,4-diyl)dipyridine-2,4-dicarboxylic acid (3A) which has been used as organic sensitizer. Investigation of light conversion efficiency (${\eta}$) of the compound uses standard measurement condition (one sun simulated irradiation, AM 1.5, 100 mW/$cm^2$) showed that it could reach 1.00% ($J_{SC}=2.63\;mAcm^{-2}$, $V_{OC}$=0.64 V and FF=0.59). Under the same conditions, the ruthenium complex (N719) gave the conversion efficiency as high as 4.02%($J_{SC}=10.50\;mAcm^{-2}$, $V_{OC}$=0.67V and FF=0.57).

• Textile Coloration and Finishing
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• v.23 no.2
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• pp.90-99
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• 2011

The aim of this study is to develope eco-printing method using natural pigments and chitosan as a natural binder. Three chitosans with different molecular weights were employed to find appropriate conditions including chitosan concentration and pigment/binder ratio. Dye uptake, color and fastnesses of the printed fabrics were evaluated to find optimum conditions within the range of experiments carried out in this study. The effectiveness of chitosan as a printing binder was examined in comparison with color, dye uptake, and fastnesses of conventional synthetic binder and guar gum. It was found that chitosans with low or medium molecular weight were appropriate. Using low molecular weight chitosan, optimum concentrations were 1.7% for charcoal, madder and chlorophyll, whereas 2.2% for ocher, yellow soil, indigo and cochineal. Regardless of molecular weight and concentration of chitosan, the color fastnesess of fabrics printed with mineral pigments were superior to those of the fabrics printed with plant and animal pigments. As pigment/chitosan ratio became higher, rubbing fastness was decreased by 1-3 grade. The colorfastness of printed fabric with chitosan binder was similar to that with synthetic binder, which was higher than that with guar gum.

• Textile Coloration and Finishing
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• v.21 no.6
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• pp.29-38
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• 2009

Natural dyes seem to be more profitable on human and environment, and recently they could be considered as a better alternative to synthesized dyes. The aim of the current work was to investigate the dyeing property and antimicrobial activity of commercial cotton fabrics dyed with kumazasa (usually called in japan) which is known as conventional japan bamboo leaves. Actually, the dyeability and antimicrobial property of dyed fabric with natural mordant/dyeing was compared with synthetic mordant/dye process. The results of this study obtained are as follows. The apparently colour of kumazasa leaves extract dyed fabrics showed with light green or slightly yellow-green. In colorfastness to washing, ${\Delta}E$ and K/S values of dyed fabrics with natural chitosan as mordant used was shown to be more excellent results, than was synthetic mordant used. However, the decrease rate was recorded nearly 50% when washing repeated 20 cycles. In result of antimicrobial effect for bacteria, the dyed fabrics didn't show the significant antimicrobial activity to the both dyed with and without mordant. Results of this investigation considered that low-cost, natural, bio-mordant are relatively effective in natural coloration.

• Membrane and Water Treatment
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• v.11 no.5
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• pp.333-344
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• 2020

Advances in industrial development and waste management over several decades have reduced many of the impacts that previously affected ecosystems, however, there are still processes which discharge hazardous materials into environments. Among industries that produce industrial wastewaters, textile manufacturing processes play a noticeable role. This study was conducted to test a novel continuous combined commercial membrane treatment using polyvinylidene fluoride (PVDF), ultrafiltration (UF), and polyamide (PA) nanofiltration (NF) membranes for textile wastewater treatment. The synthetic textile wastewater used in this study contained sodium silicate, wax, and five various reactive dyes. The results indicate that the removal efficiency for physical particles (wax and resin) was 95% through the UF membrane under optimum conditions. Applying UF and NF hybrid treatment resulted in total effective removal of dye from all synthetic samples. The efficiency of sodium silicate removal was measured to be between 2.5 to 4.5% and 13 to 16% for UF and NF, respectively. The chemical oxygen demand in all samples was reduced by more than 85% after treatment by NF.

• Textile Coloration and Finishing
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• v.19 no.3
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• pp.12-17
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• 2007

In this study, we have investigated properties and behaviors of the indigo vat dyeings on synthetic fibers, namely PET and PTT/Spandex. In addition, indigo vat dyeing conditions such as dyeing temperature, dye concentration and pH were optimized. The finding results show that higher color strengths of indigo dyeings on the two types of applied fibers were obtained at $110^{\circ}C$ and $90^{\circ}C$, respectively. Furthermore, acid leuco dyeings on the fiber substrates using acetic acid and formic acid show higher dye uptake with compared to alkali leuco counterparts.

• Textile Coloration and Finishing
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• v.30 no.1
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• pp.20-28
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• 2018

The near infrared ray camouflage fabric has a near infrared ray reluctance similar to the surrounding environment and has a camouflage effect on the surrounding environment. Synthetic fibers used in military uniforms are difficult to have gastrointestinal function as general commercial dyes, unlike cellulose fibers, which use some commercial vat dyes to impart infrared gastrointestinal function. In this study, we optimized the adsorption pH, temperature and time for NIR dye application for polyester fabrics, and established the optimum concentration for the evaluation of adsorption build-up characteristics. In addition, it is difficult to adsorb it since the polyester material has a dense crystal structure and the NIR dye is bulky. Therefore, a swelling agent used for dyeing meta-aramid fibers with high Tg and high crystallinity was introduced as a separate preparation to increase the affinity to polyester, which is a hydrophobic fiber, to thereby obtain an excellent adsorption rate. As a result of comparing before and after using swelling agent, the adsorption rate difference was 10 times or more when compared with before.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.29 no.1
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• pp.35-39
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• 2016

In this research, we focused on the improvement of cy3 dye's characteristics for LCD color filter. Solubility and thermal stability are main characteristics of dyes for LCD color filter. We performed experiment to change counter cation of cy3 dyes with alkoxy substituent for these purposes. These cy3 dyes (1b~5b) were prepared through the synthetic procedure of three steps. The synthesized new cy3 dyes were charaterized by using NMR, FT-IR, UV/Vis spectroscopy, and TGA. These cy3 dyes showed purple color and maximum absorption wavelength (${\lambda}_{max}$) in the range of 578~590 nm in UV/Vis spectrum. We confirmed that solubility and thermal stability of cy3 dyes were dependent on the structure of counter cation. Cy3 dyes with alkoxy substituent have good solubility in organic solvents such as dichloromethane, methanol, and acetone. Especially, Cy3 dye with 4-nitrobenzyl counter cation (5b) gave excellent solubility characteristics.

• Asian Journal of Business Environment
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• v.14 no.1
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• pp.15-22
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• 2024

Purpose: The development of natural batik dyes based on a combination of coconut fiber waste and avocado leaves using the extraction method is important to support the green economy and reduce chemical waste in Indonesia. Research design, data and methodology: The research explores the use of coconut fiber and avocado leaf waste extraction as a natural batik dye and conducts market testing to assess consumer satisfaction. Results: Indonesian batik exports are growing, but synthetic dye practices are causing a decline in demand. To address this, natural dyes are being explored, including coconut fiber waste and avocado leaf waste. Conclusion: Test results from washing at 40 degrees Celsius in terms of color changes and color staining, from sweat in terms of changes in acid color and changes in base color, to sunlight in terms of color fastness value, to heat to iron in terms of color change and color staining shows a value of 3-4 (quite good) and 4-5 (good), meaning that coconut fiber and avocado leaves waste can be used as natural batik dye.

• Proceedings of the Korean Environmental Health Society Conference
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• 2005.12a
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• pp.95-102
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• 2005

For decolorization of synthetic dyes, Isolate fungi were investigated for the decolorization of 8 industrial dyes. One fungus isolated from textile wastewater collected from Banweol industrial complex, Korea showed excellent ability for removing synthetic dyes. Internal Transcribed Spacers (ITS) sequencing result was confirmed as the new Basidomycetes species. HUE05-1 The optimal decolorizaton conditions were pH5, 30$^{\circ}C$ and aerobic condition. HUE05-1 was completely decolorized all dyes in both solid and liquid condition. The result is decolorization effect at Reactive Orange 16; 97.12%, Reactive Blue 19; 92.09%, Reactive Blue 49; 97.04%, Reactive Yellow 145; 95.53%, Acid Orange 10; 99.18%, Acid Violet 43; 98.73%, Acid Blue 350; 94.71%, Disperse Blue 106; 90.07%.

• Textile Coloration and Finishing
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• v.33 no.4
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• pp.202-209
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• 2021

Natural dyes are more expensive than synthetic dyes and the dyeing process, which is mainly immersion of dye, is complicated. For this reason, relatively small-scale production methods were predominant. However, awareness and interest in environmental sustainability is rising globally, and the use of synthetic dyes causes various environmental problems such as wastewater and CO₂ emission, so the consumption of natural dyes is increasing. In addition, interest in digital textile printing, an eco-friendly dyeing method that can produce products of various designs and uses less water, is growing. In this study, natural indigo dye (Indigofera tinctoria) was used as a raw material for Digital Textile Printing ink, and ¹⁴C (Biocarbon) present in it was measured to confirm whether it was derived from natural ingredients. The performance was confirmed by testing the pH, viscosity, electrical conductivity, surface tension, and particle size analysis of natural indigo ink. In addition, the performance of natural indigo DTP ink and printing fabric was evaluated by inspecting the change in color fastness and corresponding index substances before and after digital printing with natural indigo DTP ink on textiles. Through this, the possibility of commercialization of DTP ink and printing fabric using natural indigo was confirmed.