• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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• pp.993-994
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• 2008

Electrochromic (EC) devices are capable of reversibly changing their optical properties upon charge injection and extraction induced by the external voltage. The characteristics of the EC device, such as low power consumption, high coloration efficiency, and memory effects under open circuit status, make them suitable for use in a variety of applications including smart windows and electronic papers. Coloration due to reduction or oxidation of redox chromophores can be used for EC devices (e-paper), but the switching time is slow (second level). Recently, with increasing demand for the low cost, lightweight flat panel display with paper-like readability (electronic paper), an EC display technology based on dye-modified $TiO_2$ nanoparticle electrode was developed. A well known organic dye molecule, viologen, was adsorbed on the surface of a mesoporous $TiO_2$ nanoparticle film to form the EC electrode. On the other hand, ZnO is a wide bandgap II-VI semiconductor which has been applied in many fields such as UV lasers, field effect transistors and transparent conductors. The bandgap of the bulk ZnO is about 3.37 eV, which is close to that of the $TiO_2$ (3.4 eV). As a traditional transparent conductor, ZnO has excellent electron transport properties, even in ZnO nanoparticle films. In the past few years, one-dimension (1D) nanostructures of ZnO have attracted extensive research interest. In particular, 1D ZnO nanowires renders much better electron transportation capability by providing a direct conduction path for electron transport and greatly reducing the number of grain boundaries. These unique advantages make ZnO nanowires a promising matrix electrode for EC dye molecule loading. ZnO nanowires grow vertically from the substrate and form a dense array (Fig. 1). The ZnO nanowires show regular hexagonal cross section and the average diameter of the ZnO nanowires is about 100 nm. The cross-section image of the ZnO nanowires array (Fig. 1) indicates that the length of the ZnO nanowires is about $6\;{\mu}m$. From one on/off cycle of the ZnO EC cell (Fig. 2). We can see that, the switching time of a ZnO nanowire electrode EC cell with an active area of $1\;{\times}\;1\;cm^2$ is 170 ms and 142 ms for coloration and bleaching, respectively. The coloration and bleaching time is faster compared to the $TiO_2$ mesoporous EC devices with both coloration and bleaching time of about 250 ms for a device with an active area of $2.5\;cm^2$. With further optimization, it is possible that the response time can reach ten(s) of millisecond, i.e. capable of displaying video. Fig. 3 shows a prototype with two different transmittance states. It can be seen that good contrast was obtained. The retention was at least a few hours for these prototypes. Being an oxide, ZnO is oxidation resistant, i.e. it is more durable for field emission cathode. ZnO nanotetropods were also applied to realize the first prototype triode field emission device, making use of scattered surface-conduction electrons for field emission (Fig. 4). The device has a high efficiency (field emitted electron to total electron ratio) of about 60%. With this high efficiency, we were able to fabricate some prototype displays (Fig. 5 showing some alphanumerical symbols). ZnO tetrapods have four legs, which guarantees that there is one leg always pointing upward, even using screen printing method to fabricate the cathode.

• 한국염색가공학회지
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• 제18권3호
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• pp.1-9
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• 2006

In order to dye polyester/cotton blend fabric by one-bath dyeing process with single disperse dye, a novel hetero-bifunctional bridge compound(DBDCBS) was synthesized and utilized. The DBDCBS was designed to contain two different reactive groups such as ${\alpha},{\beta}$-dibromopropionylamido and dichloro-s-triazinyl groups. The ${\alpha},{\beta}$-dibromopropionylamido group shows considerable reactivity towards amines or amino groups at acidic condition and high temperature. In contrast, the dichloro-s-triazinyl group has reactivity towards hydroxyl groups at alkaline condition and room temperature. In order to examine whether as a bridge the compound could combine dyes containing amino groups with cellulosic substrates, disperse dyes containing amino group were tried to dye the cotton fibers pretreated with the DBDCBS compound. By the results, polyester/cotton blends were dyed by one-bath dyeing process with single disperse dye,1,4-diaminoanthraquinone.

• 한국염색가공학회지
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• 제21권5호
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• pp.21-26
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• 2009

In order to analyze numerically the hydrophobicity of the new dyes synthesized for unmodified pure polypropylene fibers, the octanol-water partition coefficient (logP), which is one of molecular descriptors representing hydrophobicity of organic compounds, was obtained by a semi-empirical method using Chem3D software. For the dyes of higher logP than around 5, the affinity of the dyes towards unmodified polypropylene fiber was substantial. In contrast to the new dyes for polypropylene, conventional disperse dyes have logP values lower than 5 and exhibited poor affinity.

• 한국염색가공학회지
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• 제16권2호
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• pp.1-7
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• 2004

The dyeability of cotton fabrics treated with liquid ammonia was investigated using low-temperature and high-temperature reactive dyes. From the results of dyeing rates of direct dye, the inversion time was shown at 600 hours at $40^{\circ}C$, and however it was shown at 10 minutes at $80^{\circ}C$. This was applied to reactive dyeings. In the low-temperature reactive dyes, the color strength of the fabrics treated with liquid ammonia was lower than that of mercerized fabrics. By contrast, in the high-temperature reactive dyes, the color strength of the fabrics treated with liquid ammonia was higher than that of mercerized one.

• 한국재료학회지
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• 제29권2호
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• pp.87-91
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• 2019

We report on stretchable electrochromic films of poly(3-hexylthiophene) (P3HT) fabricated on silver nanowire (AgNW) electrodes. AgNWs electrodes are prepared on polydimethylsiloxane (PDMS) substrates using a spray coater for stretchable electrochromic applications. On top of the AgNW electrode, poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) is introduced to ensure a stable resistance over the electrode under broad strain range by effectively suppressing the protrusion of AgNWs from PDMS. This bilayer electrode exhibits a high performance as a stretchable substrate in terms of sheet resistance increment by a factor of 1.6, tensile strain change to 40 %, and stretching cycles to 100 cycles. Furthermore, P3HT film spin-coated on the bilayer electrode shows a stable electrochromic coloration within an applied voltage, with a color contrast of 28.6 %, response time of 4-5 sec, and a coloration efficiency of $91.0cm^2/C$. These findings indicate that AgNWs/PEDOT:PSS bilayer on PDMS substrate electrode is highly suitable for transparent and stretchable electrochromic devices.

• 한국어류학회지
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• 제13권2호
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• pp.117-122
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• 2001

강원도 삼척시 호산리 호산천에서 채집된 꾹저구, 검정꾹저구, 무늬꾹저구 3종의 성적이형에 관하여 조사하였다. 3종은 산란기때 뚜렷한 혼인색을 나타낸다. 3종 모두 암컷에서는 두부복면, 배지느러미, 제 1 등지느러미 외연이 진한 흑색을 나타냈다. 그러나 검정꾹저구의 제 1 등지느러미 외연으로부터 1/3은 진한 흑색을 나타낸 반면 다른 2종은 짙은 황색을 나타내는 차이를 보였다. 3종의 암컷모두 복부가 짙은 황색이 되는 공통점을 나타내었다. 수컷인 경우, 꾹저구와 무늬꾹저구는 거의 같은 혼인색을 나타냈으나 뒷지느러미에 있어서 무늬꾹저구는 짙은 흑색을 나타내었고, 꾹저구는 옅은 흑색을 나타내었다. 검정꾹저구는 두부복면, 배지느러미 및 뒷지느러미가 황색을 나타낸 반면, 나머지 2종은 옅은 흑색을 나타내었다. 이들 3종의 수컷 생식공돌기는 좁고 긴 삼각형 모양이었고, 암컷은 굵고 짧은 하트모양이었다. 꾹저구는 7개의 형질 즉, 체고, 두장, 문장, 상악장, 두고, 가슴지느러미 길이, 안경 등에서 암수간에 유의한 차이가 인정되었다. 검정꾹저구는 11개의 형질 즉, 체고, 미병장, 미병고, 두고, 두장, 문장, 상악장, 두폭, 뒷지느러미 길이, 가슴지느러미 길이 및 꼬리지느러미 길이 등에서 유의한 차이가 인정되었다. 무늬꾹저구는 10개의 형질 즉, 체고, 두장, 미병고, 문장, 상악장, 두폭, 뒷지느러미 길이, 가슴지느러미 길이, 꼬리지느러미 길이 및 안경 등에서 유의한 차이가 인정되었다. 이들 형질중, 체고, 두장, 문장, 상악장 및 가슴지느러미 길이 등은 3종 모두 암수간에 유의한 차이가 인정된 형질이었는데 암컷은 체고에서만 수컷보다 높은 수치를 나타냈고, 나머지 형질에서는 수컷이 암컷보다 높은 수치를 나타냈다. 또한 암수간에 가장 큰 차이로 쉽게 구분이 가능했던 형질은 상악장으로써 수컷의 상악장은 암컷의 후연을 훨씬 넘었다 (p<0.001).

• 한국안광학회지
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• 제6권1호
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• pp.125-131
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• 2001

시중에서 시판되고 있는 완성품 선글라스를 고가형 23개, 저가형 55개를 대상으로 비파괴식 검사를 통하여 선글라스의 품질에 대한 분석을 행하였다. 선글라스렌즈의 일반적 광학성질은 규격을 대체적으로 만족할 정도였으며, 재질면에서 HIGH-type은 glass의 비율이 그리고 LOW-type은 Acrylate의 비율이 높았다. HIGH-type의 투과색은 무채색에 근접하였으나 LOW-type은 570 nm와 485 nm를 잊는 선상에 넓게 분포되었다. 렌즈 투과색의 자극순도의 규정을 벗어난 경우는 HIGH-type에서 7%, LOW-type에서 18%였다. UV/VIS cut-off는 HIGH-type의 경우에 350 nm, 380 nm, 400 nm를 초과하는 그룹으로 대별되었으며 LOW-type에서는 350 nm 이하 영역에 있는 경우가 6%에 달하였다. erythemal UV의 투과특성에 있어서 HIGH-type의 경우에는 모두 규격을 만족시켰으나 LOW-type의 경우에는 DIN 규격에서 최대 5개의 fail을 보였다. 또한 Near UV의 투과특성은 HIGH-type의 선글라스에서 더 많은 fail을 보였다. IR 투과특성에서는 LOW-type이 HIGH-type보다 열등한 특성을 보였다. 신호등 인지도의 경우에 HIGH-type은 모두 규격을 만족시켰지만 LOW-type은 21.8%가 만족시키지 못하였다. 대비감도 시력은 L의 증가와 함께 증가하였으며, 측정 거리의 감소와 함께 높아졌다. a와 b의 변화에 따른 대비감도 시력은 a-b 교점에 근접하는 경우 높은 값을 보였다. 선글라스 렌즈의 특성은 투과색, UV, IR, 신호등 가시도, 재질, 대비감도 시력 등의 종합적인 평가에 의해서 이뤄져야 하며 한가지 규격의 획일적 적용을 지양해야 한다. 비파괴식 선글라스 렌즈의 분석에 있어서 HIGH-type의 경우가 LOW-type에 비하여 종합적인 특성이 우수하였다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.407.1-407.1
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• 2016

Electrochromism is defined as a phenomenon which involves persistently repeated change of optical properties between bleached state and colored state by simultaneous injection of electrons and ions, sufficient to induce an electrochemical redox process. Due to this feature, considerable progress has been made in the synthesis of electrochromic (EC) materials, improvements of EC properties in EC devices such as light shutter, smart window and variable reflectance mirrors etc. Among the variable EC materials, solid-state inorganics in particular, metal oxide semiconducting materials such as nickel oxide (NiO) have been investigated extensively. The NiO that is an anodic EC material is of special interest because of high color contrast ratio, large dynamic range and low material cost. The high performance EC devices should present the use of standard industrial production techniques to produce films with high coloration efficiency, rapid switching speed and robust reversibility. Generally, the color contrast and the optical switching speed increase drastically if high surface area is used. The structure of porous thin film provides a specific surface area and can facilitate a very short response time of the reaction between the surface and ions. The large variety of methods has been used to prepare the porous NiO thin films such as sol-gel process, chemical bath deposition and sputtering. Few studies have been reported on NiO thin films made by using sol-gel method. However, compared with dry process, wet processes that have the questions of the durability and the vestige of bleached state color limit the thin films practical use, especially when prepared by sol-gel method. In this study, we synthesis the porous NiO thin films on the fluorine doped tin oxide (FTO) glass by using sputtering and anodizing method. Also we compared electrical and optical properties of NiO thin films prepared by sol gel. The porous structure is promised to be helpful to the properties enhancement of the EC devices.

• 복식문화연구
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• 제25권4호
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• pp.509-518
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• 2017

As the international competitive landscape deepens, the need to understand foreign cultures and establish effective strategies is increasing. At the beginning of the 20th century, Cartier actively developed exotic designs to secure international competitiveness; theses designs have also been used as design prototypes for Cartier in modern times. The purpose of this study is to analyze the color characteristics and types of exotic designs in the early 20th century, which was a turning point in Cartier's design. After studying the literature, a total of 248 exotic designs were presented in Cartier catalogs. This study also selected overseas monographs from the early 20th century, and their design types were classified and color analysis was performed based on the Natural Color System(NCS). Cartier's exotic designs cover wide range of styles, such as Chinese, Japanese, Persian, Indian and Egyptian styles. Multicolor, primary colors, and contrast are all strongly expressed. 97% of designs contained multiple colors, with at least two colors and maximum of six colors. The most frequently used colors are red, green, and blue, which means that only 9% of the designs do not contain the three colors, showing a high preference for theses three colors. In addition, color combinations of red and green, red and blue, or all three colors are used to show high contrast and utilize complementary colors, or near complementary colors, for coloration. This study is meaningful in that it analyzes the color characteristics of Cartier's exotic designs and translates them into practical data for establishing the color strategies of companies in the global market.

• 한국재료학회지
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• 제31권3호
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• pp.132-138
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• 2021

Electrochromic devices (ECDs) have been drawing great attention due to their high color contrast, low power consumption, and memory effect, and can be used in smart windows, automatic dimming mirrors, and information display devices. As with other electronic devices such as LEDs (light emitting diodes), solar cells, and transistors, the mechanical flexibility of ECDs is one of the most important issue for their potential applications. In this paper, we report on flexible ECDs (f-ECDs) fabricated using an all-in-one EC gel, which is a mixture of electrolyte and EC material. The f-ECDs are compared with rigid ECDs (r-ECDs) on ITO glass substrate in terms of color contrast, coloration efficiency, and switching speed. It is confirmed that the f-ECDs embedding all-in-one gel show strong blue absorption and have competitive EC performance. Repetitive bending tests show a degradation of electrochromic performance, which must be improved using an optimized device fabrication process.