• Carbon letters
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• v.5 no.3
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• pp.103-107
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• 2004

The atmospheric pressure plasma treatments ($Ar/O_2$ and $Ar/N_2$) of activated carbon fibers (ACFs) were carried out to introduce hydrophilic functional groups on carbon surfaces in order to enhance the hydrogen chloride gas (HCl) adsorption. Surface properties of the ACFs were determined by XPS and SEM. $N_2$/77 K adsorption isotherms were investigated by BET and D-R (Dubinin-Radushkevich) plot methods. The HCl removal efficiency was confirmed by HCl detecting tubes (range:1~40 or 40~1000 ppm). As experimental results, it was found that all plasma-treated ACFs showed the decrease in the pore volume, but the HCl removal efficiency showed higher level than that of the untreated ACFs. This result indicated that the plasma treatments led to the conformation of hydrophilic functional groups on the carbon surfaces, resulting in the increase of the interaction between the ACFs and HCl gas.

• Resources Recycling
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• v.29 no.6
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• pp.79-87
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• 2020

The extraction and stripping of HCl from aqueous solutions by commercial extractants like LIX 63 and its mixture with TEHA/ Cyanex 923/ Aliquat 336 and ionic liquids like ALi-SCN, ALi-PC in kerosene was investigated. Among these extractants, ALi-PC showed the best extraction effectivity (above 80%), but it was difficult to strip HCl from the loaded phase. Although the extraction percentage of HCl by LIX 63 was not high, the stripping performance was above 81%. The addition of octanol to the organic phase led to negative effect on the extraction performance of HCl. The addition of C2H5OH into aqueous solutions significantly increased the extraction and stripping percentage of HCl by LIX 63, ALi-PC and ALi-SCN.

• Journal of the Korean Society of Tobacco Science
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• v.18 no.1
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• pp.85-91
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• 1996

Commercially available activated carbon was treated with 0.2N NaOH/0.1N HCl to decrease the ash contents and to analyze the effect of demineralization. We have studied their properties and adsorptivity to solvents such as benzene, acetone, toluene and carbon tetrachloride, ammonia and also aldehydes of cigarette smoke. By demineralization with NaOH/HCl, surface area and pore volume were increased up to 10 - 20% according to developement of micro-pore and pH of activated carbon was also changed from 10.2 to 6.3. Surface acidity of the activated carbon treated with chemicals increased slightly. The chemical treatment led to small increase in adsorptioil properties of solvents, ammonia and aldehydes of cigarette smoke, but content of chlorine and sulfur in activated carbon were reduced. As the results of smoking test, charcoal taste caused by the activated carbon was reduced significantly by the treatment with NaOH/HCl.

• Applied Chemistry for Engineering
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• v.25 no.4
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• pp.414-417
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• 2014

LED scraps consisting of highly crystalline GaN and their leaching behavior are comprehensively investigated for hydro-metallurgical recovery of rare metals. Highly stable GaN renders the leaching of the LED scraps extremely difficult in ordinary acidic and basic media. More favorable state can be obtained by way of high temperature solid-gas reaction of GaN-$Na_2CO_3$ powder mixture, ball-milled thoroughly at room temperature and subsequently oxidized under ambient air environment at $1000-1200^{\circ}C$ in a horizontal tube furnace, where GaN was effectively oxidized into gallium oxides. Stoichiometry analysis reveals that GaN is completely transformed into gallium oxides with Ga contents of ~73 wt%. Accordingly, the oxidized powder can be suitably leached to ~96% efficiency in a boiling 4 M HCl solution, experimentally confirming the feasibility of Ga recycling system development.

• Journal of the Korean Ceramic Society
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• v.33 no.12
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• pp.1365-1372
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• 1996

In order to obtain a transparent and dimer-free Ormosil embedded with orgainc dye variations of gel struc-ture and optical properties were studied as a functiion of the change of gel composition. The Ormosils which have good optical property were produced in the 90/10 ratio of TEOS/PDMS and the structural variations of the gel were achived by the change of ratio of HCl/TEOS. As the ratio of HCl/TEOS was increased pore size of the Ormosil enlarged and porosity increased. Increasing HCl concentration led to gradually lower trans-mittance values. In the xerogel doped with the organic dye Rhodamine 6G perchlorate a dimer peak near 500nm was observed with the increase of the ratio of HCl/TEOS

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.103-104
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• 2006

Transparent conductive oxide (TCO) are necessary as front electrode for increased efficiency of LED. In our paper, transparent conducting alminum-doped Zinc oxide films (AZO) were prepared by rf magnetron sputtering on glass (corning 1737) substrate, were then annealed at temperature $400^{\circ}C$ for 2hr. The smooth AZO films were etched in diluted HCL (0.5%) to examine the surface morphology properties as a variation of the time. The surface morphology of AZO films increased as a time. We observed texture structure of AZO thin film etched for 1min.

• Resources Recycling
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• v.26 no.3
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• pp.26-31
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• 2017

LIX 63 showed a selectivity for the extraction of Pd(II) over other PGMs, such as Pt(IV), Ir(IV) and Rh(III) from 6 M HCl solution. Moreover, HCl solution has significant effect on the oxidation-reduction reaction between Ir(IV) and LIX 63. Therefore, the applicability of employing LIX 63 for the separation of the 4 PGMs was investigated from 3 M HCl solution. From 3 M HCl solution, only Pd(II) was selectively extracted by LIX 63 and its extraction percentage was higher than from 6 M HCl solution. Extraction of the Pd(II) free raffinate with TBP led to the selective extraction of Pt(IV). After oxidation of Ir(III) with $NaClO_3$ to Ir(IV), extraction of the Pt(IV) free raffinate with Aliquat 336 selectively extracted Ir(IV). For each extraction step, optimum stripping conditions were obtained. By this process, it was possible to separate the 4 PGMs by solvent extraction from 3 M HCl solution.

• Journal of Korean Society for Atmospheric Environment
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• v.23 no.6
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• pp.744-751
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• 2007

Wet scrubber is widely used to remove toxic gaseous contaminants in various industries such as semi-conductor industry, display manufacturing industry and so on. In this study, to optimize a packed bed scrubber as one of typical wet scrubber size while keeping its performance, four different packing materials were investigated at different air flow rates, liquid-gas ratios and pH values. Ammonia, hydrochloric acid and hydrofluoric acid were used as test gases to characterize the scrubber performance. Gas removal efficiency increased as the packing size decreased, which resulted in the increase of specific surface area. The increase of air flow rate led to the decrease of gas removal efficiency, while the increase of liquid-gas ratio led to the increase of gas removal efficiency. For the case of $NH_3$ gas, lower pH, and for the cases of HCl and HF, higher pH contributed to higher gas removal efficiency. Gas removal efficiency of a wet scrubber increased in the order of HCl < $NH_3$ < HF according to its water solubility.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.19 no.10
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• pp.901-906
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• 2006

The transparent conductive oxide(TCO) has been used in necessity as front electrode for increasing efficiency of LED. In our paper, aluminium-doped zinc oxide films(AZO), which has transparent conducting were prepared with RF magnetron sputtering system on glass substrate(corning 1737) and annealed at $400^{\circ}C$ for 2 hr in vacuum ambient and $600^{\circ}C$ for 2hr with $O_2$ ambient respectively. The smooth AZO films were etched in diluted HCL(0.5 %) to examine the surface properties, which in ambient post-annealing process. We confirmed that the electric, structural and optical properties of textured AZO thin films, which implemented using the methods of XRD, FWHM, AFM and Hall measurement. The properties of textured AZO thin films especially depended on the ambient post-annealing process. We presumed that the change of transmittances as R G B LED and the ambient post-annealing process will be increasing the efficiency of LED.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.593-593
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• 2013

나노패턴 제작은 차세대 초고밀도 반도체 메모리기술과 바이오칩 등 나노기술의 핵심 분야로, 나노패턴 구조를 나노-바이오 전자소자 및 반도체 산업분야에 적용할 경우 시장 선점 및 막대한 부가가치 창출 등을 통해 국가경쟁력 강화에 크게 기여할 것으로 기대된다. 하지만 대면적 패턴형성이 어려워 뿐만 아니라 $300^{\circ}$ 이상의 열처리 과정에 의한 생산성이 떨어진다. 또한 나노구조가 잘 이루어진 차원, 표면상태, 결정성, 화학적 조성을 갖도록 하는 합성 및 제조상의 어려움 때문이다. 이에 반해 자기정렬 ITO Dot 형성은 상기 기술한 1차원 나노구조형성을 하는 것에 비하여, 나노구조를 제작하기 위하여 공정이 단순하며, 비용 및 생산성 측면에서 유리 할 것으로 생각된다. 이에 본 연구는 E-beam을 이용하여 형성된 ITO 박막에 HCl solution을 이용하여 자기정렬 ITO Dot 형성 후 n-AlGaInP Vertical LED[VLED] 표면에 nano pillar의 두께에 각기 다르게 형성하였으며, 최종적으로 제작된 VLED의 전기적, 광학적 특성을 조사하였다.