• 한국결정성장학회:학술대회논문집
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• 한국결정성장학회 1998년도 PROCEEDINGS OF THE 15TH KACG TECHNICAL MEETING-PACIFIC RIM 3 SATELLITE SYMPOSIUM SESSION 4, HOTEL HYUNDAI, KYONGJU, SEPTEMBER 20-23, 1998
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• pp.103-111
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• 1998

Au fine particle dispersed TiO2 film was prepared on silica glass substrate by sol-gel dip and firing process. The films were fabricated from the system of titanium tetraisoproxie-EtOh-HCl_H2O-hydrogen tetrachloroaurate(III) tetrahydrate. The conditions for the formation of the clear solution and dissolving high concentration of Au compound were examined. And a photoreduction process was adopted to control the size of gold metal particles. Phase evolution of matrix TiO2 and variation of Au particle with UV irradiation were investigated by XRDA, SEM, TEM and UV-visible spectrophotometer. And the effect of CPCl(Cetylpyridinium chloride monohydrate) as a dispersion agent was evaluated.

• 한국결정성장학회지
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• 제9권1호
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• pp.23-28
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• 1999

Au 미립자가 분산된 $TiO_{2}$ 박막을 졸겔담금법과 열처리공정으로 실리카 유리기판위에 제조하였다. $TiO_{2}$ 박막제조는 titanium tetraisopropoxide-EtOH-HCl-$H_{2}O$-hydrogen tetrachloroaurat (III) tetrahydrate계를 이용하였다. 고농도로 Au 화합물을 함유하면서 투명한 코팅용액을 형성하는 조건을 검토하였다. Au 금속미립자의 크기를 조절하기 위하여 광환원공정을 채택하였다. UV 조사에 따른 Au 입자의 변화와 $TiO_{2}$ 매트릭스의 상전이과정을 XRD, SEM, TEM and UV-visible spectrophotometer로 관찰하였다. 분산제로서 CPCl (Cetylpyridinium chloride monohydrate)의 효과를 평가하였다.

• 한국재료학회지
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• 제13권4호
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• pp.219-223
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• 2003

Zirconia gels dispersed with fine Au particles have been prepared by the sol-gel method. Starting solution with (OC$Zr_4$$H_{ 9}$)$_4$, $C_4$ $H_{9}$ OH, $H_2$O,$ HNO_3$, $HAuC1_4$ was used to prepare gels in several molar ratio. After hydrolysis, viscosity of solutions as 4∼5 cP and gelling time of sols were spent about 9 days. As the heat-treatment temperature was increased,$ ZrO_2$ had the phase transition from tetragonal to monoclinic at $750^{\circ}C$. Heat-treatments of the gel have performed at 500, 700, 750, 800, 1000 and $1100^{\circ}C$ for 3 hrs, respectively. We have investigated TG-DTA, X-ray diffraction patterns, SEM and EDS. The size of Au fine particles dispersed in the heat-treatmented gel was about 0.15∼0.23 $\mu\textrm{m}$ and the shape was most sphericity.

• 한국세라믹학회:학술대회논문집
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• 한국세라믹학회 2003년도 추계총회 및 연구발표회 초록집
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• pp.233.2-233
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• 2003

• 한국세라믹학회지
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• 제40권5호
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• pp.475-480
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• 2003

금 미립자를 ZrO$_2$중에 분산시켜 비선형광학재료, 선택흡수막 및 투과막 등 새로운 기능성 재료로 활용하기 위하여 Au/ZrO$_2$나노복합체 박막을 제조하였다. 딥-코팅법에 의해 제조한 박막을 열처리한 후 그 특성을 엑스선 회절분석,분광분석, 주사탐침현미경 및 전자현미경 등을 이용하여 조사하였다. Au/ZrO$_2$ 박막은 150 nm의 두께를 보였으며, 박막의 표면에 분산된 금 미립자의 크기는 15~35 nm였으며, 표면거칠기는 약 1.06 nm로 막질이 우수하였다. 그리고 가시광선 영역인 600~650 nm의 파장범위에서 금 미립자의 플라즈마 공명에 의한 흡수 피_크를 나타내어 비선형광학성을 확인할 수 있었다.

• 한국세라믹학회지
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• 제43권2호
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• pp.114-120
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• 2006

Nano-size Au particle doped $TiO_2$ films were prepared with $Ti(OC_3H_7^i)_4$, polyvinylpyrrolidone(PVP), $HAuCl_4$ and $C_3H_7OH$ etc. by sol-gel method. $TiO_2$ gel films were obtained by the dip-coating method on the $SiO_2$ glass substrates, and then heat-treated at $700^{\circ}C$ for 10 min. The thickness of $TiO_2$ films were $0.7\~1.8\;{\mu}m$. It was found that the thickness of films prepared from PVP containing solution was about $2\~8$ times higher values than that of thin films without PVP. The size of Au particles doped in the films were about $350\~750\;nm$. Nano-size Au particle dispersed $TiO_2$ films showed high absorption peak at visible region 450nm, which made them good candidates for non-linear optical materials and photo-catalytic materials. The contact angle of $TiO_2$ film for water was $12.5^{\circ}$, and therefore it is clear that $TiO_2$ films have very high hydrophilic properties and the self-cleaning effects.

• Asian Journal of Atmospheric Environment
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• 제6권4호
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• pp.275-280
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• 2012

To understand the effect of aerosols on the growth and physiological conditions of trees in forests, it is important to know the state of aerosols that are deposited on the surface of the leaves or needles. In this study, we developed methods of visualization of submicron-sized aerosols that were artificially deposited from the gas-phase or liquid phase onto tree leaves or needles in trees. Firstly, we used field-emission scanning electron microscopy (FE-SEM) to observe black carbon (BC) particles that were artificially sprayed onto the leaves or needles. The distribution of BC particles deposited on the leaves and needles were distinguished based on the size and morphological features of the particles. The distribution and agglomerates size of BC particles differed between two spraying methods of BC particles employed. Secondly, we tried to visualize gold (Au) particles that were artificially sprayed onto the leaves using energy dispersive X-ray spectrometry (EDX) coupled to FE-SEM. We detected the Au particles based on the characteristic X-ray spectrum, which was secondarily generated from the Au particles. In contrast to the case of BC particles, the Au particles did not form agglomerates and were uniformly distributed on the leaf surfaces. The present results show that our methods provide useful information of adsorption and/or behavior of fine particles at the submicron level on the surface of the leaves.

• Advances in materials Research
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• 제3권3호
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• pp.139-149
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• 2014

Surface enhanced Raman Scattering (SERS) has attracted attention because the technique enables detection of various chemicals, even down to single molecular scale. Among the diverse candidates for SERS substrates, Au nanoparticles are considered promising due to their fine optical properties, chemical stability and ease of surface modification. Therefore, the fabrication and optical characterization of gold particles on solid supports is highly desirable. Such structures have potential as SERS substrates because the localized surface plasmon resonance of gold nanoparticles is very sensitive to combined molecules and environments. In addition, it is well-known that the properties of Au nanoparticles are strongly dependent on their shape. In this work, arrays of shape-controlled Au nanoparticles were fabricated to exploit their enhanced and reproducible optical properties. First, shape-controlled Au nanoparticles were prepared via seed mediated solution-phase synthesis, including spheres, octahedra, and rhombic dodecahedra. Then, these shape-controlled Au nanoparticles were arranged on a PDMS substrate, which was nanopatterned using soft lithography of poly styrene particles. The Au nanoparticles were selectively located in a pattern of hexagonal spheres. In addition, the shape-controlled Au nanoparticles were arranged in various sizes of PDMS nanopatterns, which can be easily controlled by manipulating the size of polystyrene particles. Finally, the optical properties of the fabricated Au nanoparticle arrays were characterized by measuring surface enhanced Raman spectra with 4-nitrobenezenethiol.

• 공업화학
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• 제5권2호
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• pp.285-294
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• 1994

몇 종류의 담지 금촉매를 통상의 함침법과 공침법에 의하여 제조하였다. 금입자의 크기, 산소의 흡착량, CO와 NO의 흡착특성 그리고 산화환원 특성 등의 조사를 통하여, 금의 첨가효과와 활성점의 생성에 관해 연구하였다. 함침법에 의한 촉매의 금입자들은 30~100nm 정도로 크고 균일하지 않았으나, 공침법에 의한 촉매는 약 4nm인 초미립자의 상태로 매우 균일하게 분산되어 있었다 $Au/Al_2O_3$촉매에 있어서, 불활성인 $Al_2O_3$에 금의 첨가로 $N_2O$의 분해가 일어났으며, CO의 비가역흡착은 일어나지 않았으나, $O_2$는 원자상으로 비가역흡착하였다. 산소의 흡착점은 활성점이 금입자 표면에 존재하는 원자 전부가 아니라 반구형인 금입자와 담체의 경계면 주위에 한정된 활성점이었다. 저온의 $Al_2O_3$에서는 CO의 가역흡착과 비가역흡착이 일어났지만, 소량의 금의 첨가에 의하여 어느 쪽의 흡착도 약해졌다. $Au/Co_3O_4$촉매에서 CO에 대한 친화성은 $Co_3O_4$에 비해 크게 감소하였다. 환원과정에서는 금의 첨가효과가 보이지 않고, 재산화과정에서 금의 첨가효과가 뚜렷하게 나타나, 첨가된 금은 환원상태의 코발트의 재산화를 촉진시켰다.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2006년도 총회 및 춘계학술발표회
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• pp.41-44
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• 2006

The objective of this study was to evaluate the stabilization of As and heavy metals in tailings from the Samkwang Au-Ag mine with $Ca(OH)_2$. In order to evaluate the stabilization ability of As and heavy metals in the tailings, column test was implemented with various conditions as 1) particle size of $Ca(OH)_2$, 2) mixing method and 3) flow rate of eluents during 60 days. The results showed that addition with 5% of $Ca(OH)_2$ in 1kg of the tailings had the most effective ability of stabilization up to 95%. In addition, stabilization ability of As and heavy metals in tailings was enhanced using a fine powder of $Ca(OH)_2$. Therefore, stabilization technology can be used as a remediation of As and heavy metals in mine wastes including tailings and a nearby soils from abandoned metal mines.