• 한국응용과학기술학회지
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• 제27권1호
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• pp.56-60
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• 2010

Titanium dioxide particles are used as photocatalysts, sensors, adsorbents and catalyst. Core-shell polymers of inorganic/organic pair, which have both core and shell component, were synthesized by sequential emulsion polymerization using Acrylate as a shell monomer and potassium persulfate (KPS) as an initiator. We found that when Acrylate core prepared by adding 0.5~2.0 wt% EU-S133D, Titanium dioxide / Acrylate core-shell polymerization was carried out on the surface of Titanium dioxide particle without forming the new Titanium dioxide particle during acrylate shell polymerized in the inorganic/organic core-shell polymer preparation. The structure of core-shell polymer were investigated by measuring to the thermal decomposition of polymer composite using thermogravimetric analyzer(TGA) and morphology of latex by scanning electron microscope(SEM).

• 공업화학
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• 제34권1호
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• pp.57-63
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• 2023

본 연구에서는 Abaca 나노 셀룰로오스와 이산화 티타늄(TiO₂)의 유-무기 하이브리드 복합체를 제조하였다. Abaca 나노 셀룰로오스는 Abaca 셀룰로오스를 산화시키는 방법으로 제조하였으며, 촉매로서 TEMPO (2,2,6,6-tetramethyl-piperidine-1-oxyl)를 이용하였다. TiO₂ 나노입자는 sol-gel법으로 제조하였으며 이를 나노 셀룰로오스와 하이브리드(hybrid) 시켜 복합체를 제조하였다. 제조 pH 변화에 따른 복합체의 특성과 그의 물성을 비교해 본 결과, 나노 셀룰로오스와 이산화 티타늄 결합 시 pH의 영향이 매우 컸으며, 본 실험 조건에서 pH 8에서 최적의 결합성능을 나타냈다. 또한, 제조된 복합체는 광촉매 특성을 보였으며, 이산화 티타늄의 함량이 높을수록 UV광 조사에 따라 복합체의 친수성이 증가하였다.

• 자원리싸이클링
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• 제29권2호
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• pp.55-61
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• 2020

선택적 촉매 환원법(SCR)은 여러 산업에서 질소산화물 (NOx)에 의한 대기오염을 줄일 수 있는 매우 유망한 기술이다. SCR 촉매의 소비는 기술이 발전함에 따라 매년 증가하고 있지만, 촉매의 수명은 제한되어 있으며, 일반적으로 수명이 다해 활성이 떨어진 폐촉매는 재활용 되지 않고 매립되어 처리되고 있다. 현재 가장 널리 사용되는 촉매는 V₂O₅-WO₃/TiO₂로 구성되어 있으며, 약 5%_wt의 V₂O₅와 7-10%_wt의 WO₃를 함유하고 있다. 본 연구는 2차 공급원으로부터 유용 금속을 회수할 수 있는 기술개발에 대한 전세계적인 관심과, 다양한 분야에서의 바나듐 및 텅스텐의 수요에 대한 안정적인 공급을 대비하기 위한 기술개발을 바탕으로 한다. 추출 시간, pH 의존도 및 추출 농도에 대한 연구는 희석제 exxol D80에 추출제로 Aliquat 336을 사용하여 수행되었다. 두 금속의 최적 추출을 위한 조건은 약산성(~5.0) 영역에서 0.5mol/L의 Aliquat 336을 함유한 유기상과 30분 동안 추출 반응을 수행해야 하는 것으로 확인되었다. 또한 counter-McCabe-Thiele 분석으로부터 99%의 바나듐을 제거하기 위해 1단의 단수가 필요하고, 텅스텐의 추출을 위해 2단의 단수가 필요하였으며, 향류추출공정(counter-current simulations) 방식을 통한 이론적 접근의 적합성을 증명하였다.

• 상하수도학회지
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• 제26권2호
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• pp.313-319
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• 2012

This study investigated the relative degradation of commonly known endocrine-disrupting compounds such as bisphenol A (BPA) and 17${\beta}$-estradiol (E2) using ultrasound (US) and pulsed ultraviolet (PUV) in water. The removal efficiency of BPA and E2 was determined as a function of generating power and $H_{2}O_{2}$ production. The ultrasound and PUV irradiation of the aqueous solution was performed in 3 L and 90 L stainless reactor at a constant temperature of $20^{\circ}C$ with an applied power of 200 W and 2000 W, respectively. The removal of BPA and E2 by US and PUV varied with catalysts. The experiments were conducted under the following conditions: total operating time, 30 min; initial concentration, 1 uM. In the case of E2 (10 min), % removal was 92.5/95.8/87.6/82.4, while % removal of BPA (10 min) was 62.3/82.3/91.1/67.0/64.3 in various conditions (PUV, $PUV+H_2O_2$, PUV+wire mesh, $PUV+TiO_2$ coated wire mesh), respectively.

• 한국대기환경학회지
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• 제16권5호
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• pp.521-528
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• 2000

Photocatalyzed degradation of trace level trichloroethylene(TCE) and toluene in air was carried out over near UV illuminated titanium doxide(anatase) pellet in a flow reactor. The authors investigaed the effects of humidity and trace contaminant levels on the oxidation rates of toluene. Inlet concentrations of TCE and toluene were 10∼100ppm. TCE photooxidation was very rapid under what conditions, and almost 100% conversion was achieved for TCE(up to 70 ppm) as a single air contaminant. An important finding was that competitive adsorption between humidity and trace contaminants has a significant effect on the oxidation rate of what.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.1293-1296
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• 2007

An amenity requirement of the passenger using public traffic is rising continuously, and also The Ministry of Environment established "Indoor air quality management guidelines in public facilities(Dec. 2006)". To satisfy such requirement, the photoplasma device to decrease VOCs(Volatile Organic Compounds) and suspended bacillus is applied to the underframe mounted HVAC(Heating, Ventilating and Air-Conditioning) system for train. Air purifying method of photoplasma device is optical and chemical reaction that UV-light(wavelength less than 280nm) react with catalyst material(TiO2). To analyze the efficiency of photoplasma in this study, we measured the requirement time for toluene to decease down to 0.3ppm after contaminating the passenger cabin for train to toluene 1ppm.

• Bulletin of the Korean Chemical Society
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• 제31권10호
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• pp.2861-2866
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• 2010

We studied effects of the 11-Mercaptoundecylphosphoric-acid layer formation on gold surfaces that have the interactions with the titanium dioxide surface for design of gold- titanium dioxide distribution. The atomic force microscope (AFM) was used to measure forces between the surfaces as a function of the salt concentration and pH value. The forces were analyzed with the DLVO (Derjaguin-Landau-Verwey-Overbeek) theory, to evaluate the potential and charge density of the surfaces quantitatively for each salt concentration and each pH value. The interpretation for the evaluation was performed with the law of mass action and the ionizable groups on the surface.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2015년도 춘계학술대회 논문집
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• pp.50-50
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• 2015

양극산화를 통하여 타이타늄 산화물 나노튜뷰를 제조하고 전기화학적 촉매능을 향상시키기 위하여 다양한 방법의 촉매 도핑방법을 소개한다. 특히, 단일(single step) 양극산화법과 전기충격법(potential shock)를 통한 촉매도핑법을 비교하며 장횡비(high aspect ratio)가 높은 나노튜뷰에 균일하고 효율적인 촉매도핑법 및 도핑된 나노튜뷰를 활용한 물분해 실험결과를 소개한다.

• Bulletin of the Korean Chemical Society
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• 제12권1호
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• pp.80-85
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• 1991

Laser Raman spectroscopy has been used to study the tungsta catalyst supported on titania. The surface tungsten species which forms on titania after calcination appeared to possess a structure that is independent of the initial impregnation condition. The surface polytungstate seemed to be stable only at the interfacial region since the crystalline WO$_3$ phase was observed as long as the tungsta loading was in excess of monolayer coverage. The close intact and strong interaction between the polytungstate and the titania could be evidenced from the inhibition of the phase transition of TiO$_2$ from anatase to rutile.

• 한국재료학회지
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• 제20권5호
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• pp.235-240
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• 2010

We investigated the carbon monoxide (CO) gas-sensing properties of nanostructured Al-doped zinc oxide thin films deposited on self-assembled Au nanodots (ZnO/Au thin films). The Al-doped ZnO thin film was deposited onto the structure by rf sputtering, resulting in a gas-sensing element comprising a ZnO-based active layer with an embedded Pt/Ti electrode covered by the self-assembled Au nanodots. Prior to the growth of the active ZnO layer, the Au nanodots were formed via annealing a thin Au layer with a thickness of 2 nm at a moderate temperature of $500^{\circ}C$. It was found that the ZnO/Au nanostructured thin film gas sensors showed a high maximum sensitivity to CO gas at $250^{\circ}C$ and a low CO detection limit of 5 ppm in dry air. Furthermore, the ZnO/Au thin film CO gas sensors exhibited fast response and recovery behaviors. The observed excellent CO gas-sensing properties of the nanostructured ZnO/Au thin films can be ascribed to the Au nanodots, acting as both a nucleation layer for the formation of the ZnO nanostructure and a catalyst in the CO surface reaction. These results suggest that the ZnO thin films deposited on self-assembled Au nanodots are promising for practical high-performance CO gas sensors.