• Fibers and Polymers
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• 제2권1호
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• pp.135-139
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• 2001

Poly(hydroxamic acid) resin beads were prepared and complexed with various metal ions. We used IR spectroscopy to investigate the structure of metal complex. It proved that the products formed by introduction of metal ions gave stable and colored complex. It was found that the resin bead as synthesized would be a good column packing material for continuous extraction. Energy dispersive spectroscopy was use to study the distribution of metal ions in the resin matrix. It could be tentatively concluded that adsorption and diffusion of metal ions in the chelating resins mainly depended on the loading of the resin matrix which indicated interacting sites with metal ions.

• 대한지하수환경학회지
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• 제5권1호
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• pp.30-36
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• 1998

저분자량 유기산을 이용한 in-situ flushing 토양세척기법의 실제 현장 적용성 검토를 위해 실험실에서 회분식 실험을 통하여 적당한 세척제를 선정하고 이에 따른 여러 가지 운전변수를 찾아보았다. 대상 중금속으로는 Cu를 택했고, 세척제로는 실제 토양환경에 영향이 비교적 적은 저분자량 유기산인 acetic, citric, oxalic, succinic acid를 이용했다. 유기산을 이용하여 처리한 결과 실험에 사용된 유기산들 모두 1 mM의 저농도에서는 효과를 나타내지 못했고 50 mM 이상의 고농도에서 보다 좋은 제거율을 보였는데, 50 mM과 100mM의 경우 제거율이 큰 차이를 보이지 못했다. citric arid와 oxalic acid의 경우 중성 및 약산성 상태에서 최대의 제거율이 나타났고 특히 citric arid의 경우 87.1%의 높은 제거율을 보였다. 유기산이 없을때는 강산성 상태에서 Cu의 최고제거율이 70% 정도였다. 그러나 각 경우에서의 speciation을 살펴보면 유기산이 없을 경우에는 추출된 Cu의 대부분이 유해한 free ion상태로 존재하게 되고 유기산이 있을 경우에는 추출된 Cu의 대부분이 유기산과 complex를 이룬다는 것을 알 수 있었다.

• 한국막학회:학술대회논문집
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• 한국막학회 1994년도 춘계 총회 및 학술발표회
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• pp.55-56
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• 1994

There has been many attempts to improve the membrane performance using pervaporation processes[l-3]. They are 1) blending polymer with the high flux and one with high selectivity, 2) an incorporation of functional groups interacting with permeants into a membrane through copolymerization or modification, 3) composite membrane or asymmetric membrane structure with a thin skin layer which acts as a selective layer. Among them, a polymeric membrane containing ion complex group receives an extensive attention recently because ionic complex is known to activate the water transport through ion-dipole interaction. It is especially advantageous in the separation of organic-water system. We applied the ideas of the activation of water transport through ion-dipole. We have reported on the in-sire complex membrane to separate water from aqueous aceiic acid and pyridme solution[4-5] based on the simple acid-base theory. Water transport was enhanced through in-situ complex between pyridine moiety in the membrane and the incoming acetic acid in the feed. In this case, catalytic transport mechanism was proposed. In the present study we used pyridine solution as a feed and the sulfonic acid group in the membrane.

• Bulletin of the Korean Chemical Society
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• 제34권8호
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• pp.2375-2380
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• 2013

Two metal-organic frameworks based on the connectivity co-effect between rigid benzenedicarboxylic acid and bridging ligand have been synthesized $[Zn_2(3-NO_2-bdc)_2(4,4'-bpy)_2H_2O]_n$ (1), $[Co(3-NO_2-bdc)(4,4'-bpy)H_2O]_n$ (2) (where $3-NO_2-bdcH_2$ = 3-nitro-1,2-benzenedicarboxylic acid, 4,4'-bpy = 4,4'-bipyridine). The two novel complexes were characterized by IR spectrum, elemental analysis, fluorescent properties, thermogravimetric analysis, single-crystal X-ray diffraction and powder X-ray diffraction (PXRD). X-ray structure analysis reveals that 1 and 2 are two-dimensional (2D) network structures. Complex 1 and complex 2 belong to triclinic crystal with P-1 space group. The luminescence measurements reveal that two complexes exhibit good fluorescent emissions in the solid state at room temperature. Also, thermal decomposition process and powder X-ray diffraction of complexes were investigated.

• 한국지하수토양환경학회지:지하수토양환경
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• 제27권5호
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• pp.10-17
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• 2022

Inorganic acids such as HCl, HNO₃, and H₂SO₄ have been commonly applied to soil washing of heavy metals-contaminated soil due to their cost-effectiveness. However, implementing the 'Chemical Substance Control Act' requires off-site risk assessment of the chemicals used in the soil washing. Therefore, in this study, organic acids or Fe(III)-based washing agents were evaluated to replace commonly used inorganic acids. Ferric removed heavy metals via H⁺ generated by hydrolysis, which is similar to the HCl used in the control group. Oxalic acid and citric acid were effective to remove Cu, Zn, and Cd from soil. Organic acids could not remove Pb because they could form Pb-organic acid complexes with low solubility. Furthermore, Pb could be adsorbed onto the iron-organic acid complex on the soil surface. Ferric could remove exchangeable-carbonate, Fe-Mn hydroxide, and organic matter and sulfides bound heavy metals (F1, F2, and F3). Organic acids could remove the exchangeable-carbonate and Fe-Mn hydroxide bound metals (F1&F2). Therefore, this research shows that the fractionation of heavy metals in the soil and the properties of washing agents should be considered in the selection of agents in the process design.

• Bulletin of the Korean Chemical Society
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• 제26권2호
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• pp.292-296
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• 2005

Physical and chemical properties of thexylboronic acid and its derivatives such as thexylboroxine and ethylene glycol or diethanolamine thexylboronic ester have been studied. Thexylboronic acid can be extracted from an organic solution with an aqueous sodium hydroxide solution as an “te”complex. It is readily converted into thexylboroxine in the presence of anhydrous magnesium sulfate in pentane. It reacts with simple alcohols only slowly; however, it reacts readily with excess diethanolamine in the presence of anhydrous magnesium sulfate to give the corresponding ester.

• Bulletin of the Korean Chemical Society
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• 제17권4호
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• pp.342-347
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• 1996

Voltammetric determination of phenol derivatives, such as phenol, o-, m-, and p-cresols was studied with a β-Cyclodextrin (β-CD) modified-carbon paste electrode composing of the graphite powder and Nujol oil. Phenol derivatives were chemically deposited via the complex formation with β-CD by immersing the CME into a sample solution. The resulting surfaces were characterized with cyclic and differential pulse voltammetry. Treating the CME with 1 M nitric acid for five sec after a measurement could regenerate the electrode surface. Linear sweep and differential pulse voltammograms were recorded for the above system to optimize the experimental parameters for analysing the phenol derivatives. In this case, the detection limit for phenols was 5.0×10-7M for 25 min of the deposition time with differential pulse voltammetry. The relative standard deviation was ±5.2% of 3.0×10-6M (four repetitions). The interference effect of the following organic compounds was also investigated; Bezoic acid, hippuric acid, o-, m-, and p-methylhippuric acid. Adding the organic compounds into the sample solution reduces the peak current of the phenols to about 25%.

• Bulletin of the Korean Chemical Society
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• 제32권7호
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• pp.2253-2259
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• 2011

The self-assembly of one novel organic complex based on chlorogenic acid (HCA) and 2,2'-bipyridine (2,2'-bipy) has been synthesized and characterized. The complex achieved by hydrogen-bonding interactions, adopted a 1:1 stoichiometry in a solid state. The proton transfer occurred from the carboxyl oxygen to the aromatic nitrogen atom to form salts CA${\cdot}$(2,2'-Hbipy), the 2,2'-Hbipy molecule individually occupies the pseudo-tetragonum that is formed with CA. In this paper, the interactions of CA${\cdot}$(2,2'-Hbipy) with bovine serum albumin (BSA) were studied by fluorescence spectrometry. For CA${\cdot}$(2,2'-Hbipy), HCA and 2,2'-bipy, the average quenching constants for BSA were $2.4384{\times}10^4$, $4.653{\times}10^3$, and $3.059{\times}10^3\;L{\cdot}mol^{-1}$, respectively. The mechanism for protein fluorescence quenching is apparently governed by a static quenching process. The Stern-Volmer quenching constants and corresponding thermodynamic parameters ${\Delta}$H, ${\Delta}$G and ${\Delta}$S were calculated. The binding constants and the number of binding sites were also investigated. The conformational changes of BSA were observed from synchronous fluorescence spectra.

• 대한화학회지
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• 제7권3호
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• pp.216-224
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• 1963

有機含鹽素 에스테르, 알콜, 및 산과 金屬亞鉛 및 錫을 dimethyl formanmide 溶媒存在下에서 反應시킨 結果 有機金屬 콤프렉스를 좋은 收率로 生成하였다. 같은 反應을 混合紫外線照射下에서 進行시킨 結果 高溫 以外에서는 콤프렉스의 生成이 크지못하였다. D.M.F.에 依한 金屬 콤프렉스의 溶解效果는 토루엘이나 사이크로헥산보다 훨씬 컸었다. 鹽素를 含有한 酸에서는 酸의 金屬鹽의 金屬 콤프렉스가 生成됨을 觀察하였다. 카보닐 precursor와의 反應에 있어서는 少量의 雙合物과 함께 附加物을 生成하였으나 收率이 높지 못하였다(산 30∼40%, 에스테르 73%, 알콜 14.6%). 그러나 이 方法은 從來法에 比하여 簡便한 것임을 알았다. 硏究結果를 溶媒效果에 關聯시켜 論議하였으며 實驗方式을 報告하였다.

• 한국세라믹학회지
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• 제30권4호
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• pp.259-264
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• 1993

In this research, the organic tenside R11OSO3- with long alkyl-chain was synthesized, and the intercalationscomplexes fo montmorillonite were formed by the substitution of metallic cation in the montmorilonite by the synthesized organic tenside in following two methods, and the behaviors of the tenside R11OSO3- in the interlamellar space of montmorillonite were studied udner various conditions: 1) In order to protonize the sulfate group of R11OSO3-, the H3O-Montomorillonite, which acts as acid, was synthesized. And then, the organic tenside was intercalated in the interlamellar space of this H3O-Montomorillonite. And thus, the intercalations-complex of R11S-H3O-Montomorillonite was formed. The basal spacing obtained was about 33.84$\AA$. 2) The betaine compound R11OSO3- as a neutral molecule was direct intercalated in the interlamellar space of Na-Montmorillonite under water, and the intercalations-complexes of R11S-H2O-Montmorillonite was synthesized. In this case, the based spacing of bout 23.62$\AA$ was obtained.