• 한국분말재료학회지
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• 제27권1호
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• pp.58-62
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• 2020

Recently, electrochromic devices (ECDs) have gathered increasing attention owing to their high color contrast and memory effect, which make them highly applicable to smart windows, auto-dimming mirrors, sensors, etc. Traditional ECDs have a sandwich structure that contains an electrochromic layer between two ITO substrates. These sandwich-type devices are usually fabricated through the lamination of two electrodes and followed by the injection of a liquid electrolyte in the inner space. However, this process is sometimes complex and time consuming. In this study, we fabricated ECDs with a lateral electrode structure that uses only an ITO substrate and an all-in-one electrochromic gel, which is a mixture of electrolyte and electrochromic material. Furthermore, we investigated the EC properties of the lateral-type device by comparing it with a sandwich-type device. The lateral-type ECD shows strong blue absorption as the applied voltage increases and has a competitive coloration efficiency compared to the sandwich-type device.

• 한국세라믹학회지
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• 제22권5호
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• pp.47-53
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• 1985

In view of innovated utilization of Korean clay resources conventional techniques for pulverization are reviewed in comparison with fluid energy milling processes of fluidized-bed type. Throughout experiment indigenous halloysite ores (white grade) after usual pretreatment are employed as typical sample. It is evidenced that grinding by means of porcelain ball mills has limitation in reducing clay particles to less than 10${\mu}{\textrm}{m}$ in diameter regardless of whether it is processed in dry or wet. Upon use of tungsten carbide bull mill particulation to submicron sizes could be effected with relative ease but severe coloration in grey is attended indicating metallic contamination possibly from friction of the grinding apparatus itself. In contrast the modified fluid en ergy milling enables particulation to $\leq$10${\mu}{\textrm}{m}$ in diameter with simultaneous classification int olimited ranges of particle size distributions. Since this technique is in principle based on the interparticle collisions rather than on the frictions between particles and mill surfaces minimum impurity attendance would be an additional advantage. Evidence leads to the conclusion that the fluidized-bed type milling is regarded as highly effective in puverization as well as fractionation of the clay minerals under examination. This is especially so in contemplating high-value and/or high-purity clay products.

• Journal of Electrochemical Science and Technology
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• 제12권1호
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• pp.146-158
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• 2021

This paper reports the preparation of an ink-jet printed flexible electrochromic device based on a water-soluble viologen-functionalized dendrimer. Polyamidoamine (PAMAM) dendrimers were modified with different concentrations of 1-1 bis(propylamine)-4,4'-bipyridylium dibromides to obtain solution-processable electrochromic materials (K1/2 and K1). FTIR, NMR, and elemental analyses are used to characterize synthesized viologens. Moreover, their electrochemical properties were investigated using cyclic voltammetry in an electrolyte solution consisting of 0.1 M HCl to find the optimum viologens. The low-cost ink-jet printer was used to print the prepared water-soluble electrochromic inks onto the ITO coated PET substrate to form desired transparent patterns. The electrolyte was applied on the printed electrochromic ink to make a sandwich with another ITO coated PET to prepare the electrochromic devices (ECD). By applying an electrical potential (0 to -2 V), the transparent ECD's color changed from colorless to blue. The color changes for the optimum ECD (K1), which had more viologen units on the dendrimer, was accompanied by an optical contrast of 47% and 311.5 ㎠C-1 coloration efficiency at 600 nm.

• 한국전기전자재료학회논문지
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• 제36권1호
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• pp.1-9
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• 2023

According to the recent global warming, it is necessary to use energy efficiently together with eco-friendly energy. The development of alternative technologies is requisite for managing the current energy and climate crises. In this regard, "smart windows," which can control solar radiation, can be used to mitigate energy demands. Electrochromic devices (ECDs) effectively control the amount of solar energy reaching commercial and other living areas and maintain climate conditions via color modulation in response to small external stimuli, such as temperature and light irradiation. However, the performance and the stability of ECDs depend on the state of the electrolyte and sealing of the device. To resolve the aforementioned issues, an ECD was manufactured by using a poly (methyl methacrylate) (PMMA)-based gel polymer electrolyte (GPE), and a laminating method was used to adequately seal the ECD. The concentrations of PMMA, acetonitrile (ACN), and ferrocene (Fc) were controlled to optimize the composition of the GPE to achieve an enhanced electrochromic performance. The fabricated GPE-based ECD afforded high optical contrast (~81.92%), with high electrochromic stability up to 10,000 cycles. Moreover, the lamination method employing the GPE could be used to fabricate large-area ECDs.

• 한국염색가공학회지
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• 제22권2호
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• pp.173-179
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• 2010

In this study, we determine the stretch and shrinkage properties of conjugated yarns. The shrinkage(%) and elasticity(%) were determined by applying twist conditions of 0, 350, 800, 1000, 1200, 1400, 1600, 2000 T/M (twisting per meter). It is found that the shrinkage(%) and elasticity(%) gradually decreased with increasing T/M. Especially the elasticity(%) dramatically decreased over 1400 T/M condition. In contrast, it is showed that the handle and drapery properties decreased below 1000 T/M, which indicates that the optimal T/M condition could be 1000~1400. The effect of shrinkage(%) and elasticity(%) with different steam setting temperatures (60, 70, 80 and $90^{\circ}C$) was also determined. The shrinkage(%) decreased with increasing setting temperature, while the elasticity not changed. In this context, the optimal steam setting temperature could be $80^{\circ}C$ because it is not easy to weave with the yarns which was set below $80^{\circ}C$. The elasticity(%) decreased with increasing the density of warp and weft. To produce soft handle, excellent drapery and good stretch fabrics, the warp density needs to be reached by 90% of the ideal warp density. In the case of NaOH treatments to the fabrics, the elasticity(%) increased with increasing weight reduction. Therefore, this study have demonstrated that the conjugated yarns with core yarn and the SDY CD(cation dyeable spindraw yarn) as an effect yarn would be appropriate to produce excellent mixture-yarn, which displays clean appearance, good handle and excellent elasticity, The optimized conditions are as follows; 1000~1200 twist per meter, $80^{\circ}C$ steam setting temperature, 90% of ideal warp density and relaxation condition treated with 5g/l NaOH concentration.

• 한국의류산업학회지
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• 제13권6호
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• pp.838-847
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• 2011

The object of this study is as follows. First, according to the silhouette of clothes, I will search the relationship with the embroidery design. Second, I will investigate the relation of coloration about the clothes color and embroidery color. Third, I will search the relation with the image in clothes and embroidery design characteristic. The data acquisition is selected to the total 447 pictures of embroidery clothing design from the www.style.com, www.samsungdesign.net which are the related information site. The data are limited from S/S season in 2004 till F/W season in 2008 in the Paris, Milano, and New York collection. The analytical method was made through the analyze method and statistical method. First, on the relation with the clothes silhouette and embroidery design, if the satin stitch technique is utilized as the X-shaped or A-line silhouette in the one-piece and dress, the image which is elegant and feminine can be expressed. if the satin stitch technique is utilized as the H-line silhouette in jacket and court, the mannish image can be expressed. Second, the embroidery color showed up as the contrast combination of the monotone when the clothes color was the monochrome. And the embroidery color showed up as the tone in which is bright and sober when clothes color had 2 or 3 or 4. So, if the embroidery color is utilized as the similar color scheme, it will be effective. Third, if the embroidery technique of the one-piece and dress is utilized as the the satin stitch technique and the bloom and leaf motive being stylized pattern is used in the all-over and border pattern, It will be effective to express the romantic/feminine, ethnic/folklore, active, and classic image.

• 한국염색가공학회지
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• 제30권3호
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• pp.168-179
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• 2018

The modified surface of specialty carbon black(SCB) is one of the main technical factors for producing a uniform color and stable dispersion. In this work, the carboxylation or sulfonation process of SCB was used to improve the dispersive properties of hydrophilic solvents such as 1,6-hexanediol and propylene glycol monomethyl ether acetate(PGMEA). The results showed that the color strength of SCB DC2500G changed little with a range of 0.128~0.941(${\Delta}E$) compared to other SCB DC2500G material. In contrast, in the case of SCB EG410, there was a uniform color value with a range of 0.144~0.252(${\Delta}E$). Also, in our experiments, a modified SCB was confirmed by printing ink material as a melt coating paper. It may be possible that the SCB EG410 material can be advantageous as a gravure ink product. Finally, the modified SCB obtained from this research will have a large impact on the industry as a potential material for toners, paint, rubber, fillers, and other carbon black additives.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.232.1-232.1
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• 2014

The green displays are the human friendly displays, the nature friendly displays, and the economical displays. Electrochromic displays are low cost and environmental devices because they do have more choice of colours and use much less power. The elements of the electrochromic devices consist of at least two conductors, an electrochromic material and an electrolyte. The optical properties were obtained using the optical contrast between the transparency of the substrate and the coloured state of the electrochromic materials. These devices can be fully flexible and printable. Due to the characteristics of the high coloration efficiency and memory effects, the electrochromic devices have been used in various applications such as information displays, smart windows, light shutters and electronic papers. Among these technical fields switchable mirrors have been received much attention in the applicative point of view of various electronic devices production. We have developed a novel silver (Ag) deposition-based electrochromic device for the reversible electrodeposition (RED) system. The electrochromic device can switch between transparent states and mirror states in response to a change in the applied voltage. The dynamic range of transmittance percent (%) for the fabricated device is about 90% at 550 nm wavelength. Also, we successfully fabricated the large area RED display system using the parted electrochromic cells of the honey comb structure.

• 한국염색가공학회지
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• 제25권4호
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• pp.254-261
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• 2013

In this study, we synthesized a new fluorescent polypyridyl dye 2 containing a 2,2'-bipyridine in the center and two 2,2':6',2"-terpyridines at both ends. When exposed to various metal ions, the dye 2 showed selective fluorescence responses. In the presence of $Cu^{2+}$ and $Ni^{2+}$, it exhibited a highly effective fluorescence quenching, leading to large $K_{sv}$ values of up to $10^5$. In response to most other metal ions including $Al^{3+}$, in contrast, its fluorescence changes little, showing a small Ksv value at $10^2$. Meanwhile, the compound 2 revealed a differentiated fluorescence response to $Zn^{2+}$, which is evidenced by a large red shift of > 100 nm. Such a red shift from the ion binding is attributed to the planarization of the bipyridyl unit extending the effective conjugation length in conjunction. A polypyridyl compound will find important usefulness in chemosensor application due to its selective binding to metal ions. Subsequent research concerned with modified derivatives is currently going on, as a way to provide high solubility even after metal-complexing.

• 한국수산과학회지
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• 제40권4호
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• pp.234-242
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• 2007

We examined the cause of albinism in a hatchery population of flounder in terms of environmental and nutritional factors, including the effects of light intensity (130-12,300 lux), photoperiod (12L/12D or 24L/0D), tank substrate (concrete or fiber-reinforced polymer), tank color (white or dark green) and supplement with enriched live food, and also compared the growth of normal and albino fry under both 12L/12D and 24L/0D. Further to, normalization of the skin pigmentation pattern on the ocular side has been juvestigated after rearing the albino fry for 2 years after their identification and classification and found that, light intensity did not play a critical role in the development of normal pigmentation or albinism in the flounder. By contrast, the photoperiod was a weak inducer of albinism in the flounder. Tank substrate and color also affected the hypomelanosis on the ocular side of the flounder fry. The choice and supplementation of enriched live foods could drastically reduce the incidence of albinos in hatcheries. On comparing the growth of normal and albino fry, while there was no difference between the groups under 24L/0D, the growth of the albino flounder was slower under 12L/12D. Although coloration resulting from xanthophore and melanophore, but not iridophores, occurred on the ocular side, evidence of albinism remained on the ocular side of flounders.