• Proceedings of the Korean Society of Dyers and Finishers Conference
• /
• 2007.11a
• /
• pp.133-134
• /
• 2007

• Proceedings of the Korean Society of Dyers and Finishers Conference
• /
• 2007.11a
• /
• pp.83-84
• /
• 2007

• Clean Technology
• /
• v.27 no.3
• /
• pp.261-268
• /
• 2021

Equilibrium, kinetics, and thermodynamics of adsorption of acid black 1 (AB1) by coal-based granular activated carbon (CGAC) were investigated with the adsorption variables of initial concentration of dye, contact time, temperature, and pH. The adsorption reaction of AB1 by activated carbon was caused by electrostatic attraction between the surface (H⁺) of activated carbon and the sulfite ions (SO₃^-) and nitrite ions (NO₂^-) possessed by AB1, and the degree of reaction was highest at pH 3 (97.7%). The isothermal data of AB1 were best fitted with Freundlich isotherm model. From the calculated separation factor (1/n) of Freundlich, it was confirmed that adsorption of AB1 by activated carbon could be very effective. The heat of adsorption in the Temkin model suggested a physical adsorption process (< 20 J mol^-1). The kinetic experiment favored the pseudo second order model, and the equilibrium adsorption amount estimated from the model agreed to that given by the experiments (error < 9.73% ). Intraparticle diffusion was a rate controlling step in this adsorption process. From the activation energy and enthalpy change, it was confirmed that the adsorption reaction is an endothermic reaction proceeding with physical adsorption. The entropy change was positive because of an active reaction at the solid-liquid interface during adsorption of AB1 on the activated carbon surface. The free energy change indicated that the spontaneity of the adsorption reaction increased as the temperature increased.

• KSBB Journal
• /
• v.22 no.5
• /
• pp.271-277
• /
• 2007

Natural pigments have many applications like colouring agent, pigments, food additives, and antiseptics. At present, instead of synthetic pigments that have contributed to the development of industry, many kinds of natural pigments have been developed. The constituents of gardenia fruits, Gardenia jasminoides ELLIS, are traditionally known as herb medicine and natural dyes/pigments due to the customer is needs. The fruits produce yellow carotenoid pigments and iridoid compounds. The two main components in the yellow pigments are called crocin and crocetin. The extraction mode of yellow pigment from Gardenia is depended upon the extraction time, temperature, and volume of solvent. Red pigments or blue pigments formed from geniposide and amino acids have been reported a lot. Geniposide, the principal iridoid glucoside contained in gardenia fruit, was hydrolyzed to genipinic acid or genipin as a precursor for the pigment by enzymatic or chemical reaction. These red or blue pigments prepared with materials hydrolyzed of geniposide and amino acid and had properties governed by the electrostatic character of the amino acid. The pigments showed good stability to heat and pH but were gradually bleached by light while the other natural pigments are unstable in light, heat, acid, and base solution. The safety of the pigments was considered to be of little virulences in comparison to synthetic pigments.

• Clean Technology
• /
• v.10 no.3
• /
• pp.131-137
• /
• 2004

Due to the low biodegradability of dyes, conventional biological wastewater treatment systems are inefficient in treating textile wastewater. In this study, white rot fungus, Trametes versicolor KCTC 16781, were investigated for the decolorization of Reactive black 5 solutions. This fungus was able to degrade the dye solutions by the ligninolytic enzymes (laccase and MnP) produced. The enzyme activity remained constant until the end of reaction. The combined process of biological treatment and ceramic membrane showed better efficiency for decolorization and TOC removal than each single process.

• Textile Coloration and Finishing
• /
• v.6 no.2
• /
• pp.30-39
• /
• 1994

To study the printing behaviors of Polyester and cotton(P/C) fabrics printed with disperse and reactive dyes, the effects of alkalis on the fixation of reactive dyes and the alkali-stability of disperse dyes in various methods of fixation were examined. The anthraquinone disperse dyes which have diamino derivatives as substituents without hydroxy group, such as C.I. Disperse Violet 1(D.V.1), C.I. Disperse Violet 28(D.V.28) and C.I.Disperse Blue 60(D.B.60) showed good results of fixation without regard to the concentration of NaHCO$_3$. In case of high temperature steaming(HTS) and unsaturated steaming(US)/HTS, D.V. 1 was alkali-stable and effective for P/C printing. A good result was obtained with D.V.1 and C.I.Reactive Orange 13(R.O.13) paste of 4% $K_{2}CO_{3}$. It was found that the unfixed D.V.28 bearing chloro group can hinder the fixation of monochlorotriaxinyl reactive dyes, and D.B.60 made little stain on 100% cotton. In thermosol(Tm), the dye uptake of D.V.1 was not decreased so much, but those of D.V.28 and D.B.60 were greatly decreased.

• Proceedings of the KIEE Conference
• /
• 2011.07a
• /
• pp.1509-1510
• /
• 2011

염료 감응형 태양전지 동작에 있어 상대전극 표면에서 전해질의 산화, 환원 반응이 일어나기 위한 촉매의 역할이 중요하며 그 중 Pt는 촉매로써 널리 쓰이는 물질이다. Pt 도포 방식은 sputtering, Pt paste를 이용한 doctor blade, Pt solution을 이용한 spin coating 등 여러 가지가 있으며 제작 조건에 따라 그 특성도 다르게 된다. 따라서 본 연구에서는 Pt solution의 열처리에서 온도를 달리하여 그에 따른 특성을 알아보자 하였다. 그 결과 Pt solution 소성온도가 $400^{\circ}C$일 때, 가장 적절한 Pt층이 형성되기 때문에 산화, 환원반응이 활발하게 되어 높은 효율(6.8%)의 DSC 특성을 얻을 수 있었다.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2013.02a
• /
• pp.676-676
• /
• 2013

무기물 양자점을 광감응 염료로 사용하는 경우 양자점의 사이즈 조절만으로 밴드갭을 조절할 수 있어 광학적 특성 조절이 용이하며, 유기 염료보다 광흡수 능력이 뛰어난 장점을 가진다. 특히 카드뮴 계열의 CdS, CdSe 양자점을 순차적으로 증착하여 사용하는 경우 가시광 전 영역을 효율적으로 흡수, 이용할 수 있어 광전기화학 셀의 광전극으로 사용 시 높은 성능을 기대할 수 있다. 하지만, 카드뮴 계열 양자점의 경우 광전기화학 셀로의 구동에 있어 안정성이 낮은 문제점이 있으며, 이는 양자점에 남아있는 정공이 관여하는 양자점 부식 반응으로 인한 것이다. 본 연구에서는 보다 안정적이면서도 고효율의 광전기화학적 수소생산 시스템을 위해, CdSe/CdS 양자점 감응형 ZnO 나노선 광전극에 IrO2 촉매물질을 증착하였다. CdSe/CdS 양자점이 가시광 전 영역을 흡수하며, ZnO 나노선 구조를 통해 생성된 광전자를 효율적으로 포집하여 높은 광전류 특성을 기대할 수 있다. 나아가 산소생산용 조촉매로 많이 사용하는 $IrO_2$ 촉매 물질의 추가증착을 통해 양자점에서 생긴 정공을 빼 줌으로서 정공이 관여하는 양자점 부식 반응을 방지할 수 있다. 실험결과 촉매물질의 증착 이후 광전류 생성 특성 및 수소생산량이 증가하였으며, 안정성 또한 상당히 향상된 것을 확인할 수 있었다.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2013.08a
• /
• pp.189.2-189.2
• /
• 2013

1차원 산화아연 나노구조물은 광대역 에너지 밴드갭(~3.3 eV)과 독특한 물리적 특성을 갖고 있어, 전계효과 트랜지스터(field effect transistor), 발광다이오드(light emitting diode), 자외선 광검출기 (ultraviolet photodetector) 및 태양전지(photovoltaic cell)에 널리 이용되고 있다. 특히, 1차원 산화아연 나노구조물은 직접천이형 에너지 밴드갭(direct bandgap)을 갖고 있으며, 빛으로부터 여기된 전자가 1차원 나노구조물을 통해 향상된 이동경로를 제공할 수 있어서 차세대 자외선 광검출기 응용에 대한 연구가 활발히 진행되고 있다. 한편, 수열합성법(hydrothermal method)을 통해서 1차원 산화아연 나노구조물을 비교적 간단하고 저온공정을 통해서 합성할 수 있는데, 이를 광검출기 소자구조에 응용에서 양전극에 연결하기 위해서는 복잡하고 정교한 공정이 필요하다. 이에 본 연구에서는 수열합성법을 통해 합성된 산화아연 나노로드가 포함된 에탄올 용액을 금(Au) 패턴에 drop-casting을 통해서 간단한 방법으로 metal-semiconductor-metal (MSM) 광검출기를 제작하여 광반응 특성을 분석하였다. 또한 염료를 통해 가시광을 흡수하여 광전류(photocurrent)를 발생시킬 수 있도록 염료를 흡착한 산화아연 나노로드를 이용하여 같은 구조의 MSM 광검출기를 제작하여 가시광에 대한 광반응 특성을 관찰하였다.

• Applied Chemistry for Engineering
• /
• v.18 no.6
• /
• pp.650-653
• /
• 2007

$SnO_2$-doped $TiO_2$ powder was obtained from tin (IV) bis(acetylacetonate) dichloride and titanium diisopropoxide bis(acetylacetonate) with quinacridone as the dye sensitizer molecule. The structural changes of the reaction mixture were monitored by fourier transform infrared (FT-IR) spectroscopy. The morphology and microstructure of gel powder were studied by field-emission scanning electron microscopy (FE-SEM) and X-ray diffractometry (XRD). The photocatalytic activity of these powders with the anatase structure was investigated by using indigo carmine solution as a test dye