• 한국군사과학기술학회지
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• 제17권5호
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• pp.672-679
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• 2014

To improve sensing capability of infrared, heat-resistance and mechanical properties, the $SiO_2$ and $TiO_2$ anti-reflective layers were coated on sapphire substrate by MOCVD. The standard wavelength was 4,600nm, and the thickness of anti-reflective layers were 379 and 758nm in case of ${\lambda}/4$ and ${\lambda}/2$ of incident angle($65^{\circ}$), respectively. The $SiO_2$ and $TiO_2$ anti-reflective layers were coated 12.6 and 9.7nm/min of deposition rates by increasing oxygen pressure to set the ideal refractive index of 1.283. In case of $SiO_2({\lambda}/2)$ coating, the transmittance increased from 55.0 to 62.7%. The transmittance of $TiO_2({\lambda}/2)$ anti-reflective layer also increased from 55.0 to 64.8%. The flexural strength of $SiO_2({\lambda}/2)$ and $TiO_2({\lambda}/2)$ layer coated sapphire increased from 337.8 to 362.9 and 371.8MPa, respectively. The flexural strength at $500^{\circ}C$ of these materials also increased respectively to 304.5, 358.2MPa from 265.9MPa. From these results, we confirmed these materials can be used as transmission window of infrared light.

• Journal of the Optical Society of Korea
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• 제17권2호
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• pp.142-147
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• 2013

In order to deduce the difficulty of fixing the Ritchey-Chretien (R-C) dual reflective optical system and enhance the stability of the secondary mirror, a compact integral structure is presented here composed of two transmitting and two reflective aspheric surfaces. The four surfaces were manufactured from a single germanium lens and integrated together. The two reflective surfaces formed by coating the inner reflecting films were assembled in one lens. It makes the installation of the two mirrors easier and the structure of the secondary mirror more stable. A design of mid-wave infrared (MWIR) compact imaging system is presented with a spectral range chosen as $3.7-4.8{\mu}m$. The effective focal length is f=90 mm. The field of view (FOV) for the lens is $4.88^{\circ}$. It has good imaging capability with Modulation Transfer Function (MTF) of all field of view more than 0.55 close to the diffraction limitation. Outdoor experiments were carried out and it is shown that the integral catadioptric optical system performs well on imaging.

• 한국재료학회지
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• 제23권12호
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• pp.672-679
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• 2013

$Fe_4[Fe(CN)_6]_3$ coated on a mica or $TiO_2$/mica surface as infrared reflective blue pigment was prepared by a hydrothermal method. $Fe_4[Fe(CN)_6]_3$, used as coloring agent, was uniformly coated on mica or $TiO_2$/mica under the optimized condition of a 1.2 : 1 weight ratio between iron(III) chloride hexahydrate and potassium ferrocyanidetrihydrate at the initial pH level of 4.5 at $70^{\circ}C$. The infrared (IR)-reflective pigments were characterized by SEM, Zeta-potenial, FT-IR, and UV-VIS NIR spectrophotometry. Especially the CIE color coordinate and total solar reflectance(TSR) properties of the pigments were investigated in relation to variation of the coating and coated substrate thicknesses. Isolation-heat paint was prepared with 20 wt% blue pigments fully dispersed in acryl-urethane resin and several additives to coat the film uniformly. The films were also measured with CIE color coordinate, TSR, and the surface temperature was recorded by an isolation-heat measuring system. The pigments and films of $Fe_4[Fe(CN)_6]_3$ coated on mica and $TiO_2$/mica showed high TSR values compared with the TSR value of $Fe_4[Fe(CN)_6]_3$ itself. According to the increase of TSR value, the property of isolation-heat is effective. To realize the optimal blue color, we applied the the pigment to $TiO_2$ coated mica(TM(b)) which has blueish interference color. The pigment of $Fe_4[Fe(CN)_6]_3$ coated on TM(b) shows a strong blue color compared with that of $Fe_4[Fe(CN)_6]_3$ coated on $TiO_2$/Mmca(TM(w)), which has a whitish interference color.

• 한국산학기술학회논문지
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• 제13권8호
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• pp.3800-3805
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• 2012

본 논문에서는 도심 열섬현상 방지 및 에너지 효율을 높이기 위하여 적외선 반사율이 30%이상인 건물 내 외장재용 흑색 차열안료 및 도료에 대한 연구를 하였다. 안료는 $Fe_2O_3$과 $Cr_2O_3$의 혼합원료를 $900{\sim}1,200^{\circ}C$에서 소성하여 합성하였으며, 도료는 합성한 안료에 아크릴수지와 기타첨가제를 사용하여 제조하였다. 연구결과, Cr과 Fe을 1:0.9 몰비로 혼합하여 $1,000^{\circ}C$에서 소성한 안료의 발색도가 가장 우수하였고, 차열안료 20%에 분산제 1.5%를 첨가하여 제조한 차열도료로 $125{\mu}m$ 두께의 도막을 형성시켰을 때 적외선 반사가 가장 우수하였다. 차열도료와 일반도료의 표면온도 차이는 $36.5^{\circ}C$로 나타났으며 700~2,500nm 파장대의 적외선 반사율(TSR)은 39.3%로 측정되었다. 또한, 500시간의 내후성 평가에서 색상변화는 거의 나타나지 않았다.

• 한국표면공학회지
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• 제57권2호
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• pp.98-104
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• 2024

In order to overcome the urban heat island effect, highly functional paint is attracting attention as a promising means by shielding heat on the structure (building) surface. When a paint was prepared containing nano-sized silica particles, the heat-insulating performance was relatively higher than that of paints with other sizes. In addition, developed paints showed enhanced properties such as chemical resistance and abrasion resistance test because of the presence of nano-sized silica included in functional paint.

• 한국결정성장학회지
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• 제33권5호
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• pp.191-195
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• 2023

핸드폰 Backcover에 적용한 3층 나노코팅 필름을 롤투롤(roll-to-roll) 연속 공정을 통하여 제조하였다. 세라믹/금속/세라믹 3층 구조의 코팅층을 도입함으로써 금속 고유의 반사 특성을 유지하면서 전기적으로는 절연 특성을 유지하였다. 길이와 폭이 각각 1500 nm, 500 nm인 대면적 PET 필름 위에 도입된 복합 코팅층의 두께는 60 nm 이하를 보였고 모든 영역에서 균일한 두께를 유지하고 있음을 확인하였다. 나노코팅 필름의 파장대(240~1600 nm)에 따른 투과율은 파장이 증가함에 따라 투과율 역시 점차 증가하고 있으며, 적외선 영역인 1,000 nm에서 약 48 %, 가시광선 영역에 해당하는 550 nm에서는 약 35.5 %의 투과율을 보였다. 이는 코팅된 Backcover의 요구 수준(< 40 %)에 부합한다.

• 한국진공학회지
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• 제21권1호
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• pp.22-28
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• 2012

건물일체형 태양전지는 투명 연료감응형 태양전지 기술을 중심으로 연구개발이 진행되고 있다. 신뢰성-수율 개선 및 대면적화의 필요성 때문에 잘 정립된 박막 공정 기술에 기초하는 Si계 박막 태양전지가 건물일체형 태양전지를 구현할 기술로서 새롭게 조명 받고 있다. Si계 박막 태양전지에 선택적 투과막을 적용하면 가시광선은 태양전지를 투과하고 적외선은 광흡수층으로 반사되기 때문에 투명 태양전지의 변환효율이 향상된다. 본 연구에서는 선택적 투과막의 증착 기술로서 생산성 측면에서 유리한 스퍼터 증착을 이용하여 AlTiO 선택적 투과막을 형성하고 증착 조건을 조절하여 투과율을 향상시켰다.

• Journal of Ceramic Processing Research
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• 제20권spc1호
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• pp.86-91
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• 2019

A solid-state route was used to prepare sodium titanium oxide (NTO, Na2Ti3O7) as a solar heat protecting material with an impressive solar reflectance (TSR = 94.3%) using a high refractive index rutile TiO2. The solar reflectance of the synthesized NTO was measured using UV-Vis-NIR spectrophotometer. Solar reflectance property of the synthesized compound depends on the calcination temperature. The solar reflectance property of the synthesized NTO powder was compared with commercial rutile TiO2. The compound synthesized at 900 ℃ for 24 hrs had remarkable solar reflectance 94.3% than that calcined below 900 ℃. Crystalline nature, structural property, morphology and optical properties of NTO powders were characterized and analyzed using XRD, FE-SEM, EDS and UV-Vis-NIR spectrophotometer. From the results, we guessed that NTO would be a suitable "solar heat protecting candidate" for energy-saving applications in coating industries.