온도변화에 따른 Rare Earth Oxaltes Hydrate의 구조변화에 관한 연구

정오진,정학진 조선대학교 원자력연구소 1983 原子力硏究 Vol.3 No.-

희토류 옥살산 수화물의 구조는 시차열분석, 열중량분석법, X선회절법 및 전자현미경법으로 연구하였다. 각 전이점까지 가열한 옥살산 시료들의 구조변화는 X선회절 및 전자현미경 분석법에 의해 검토하였다. 이들 시료들은 공기중에서 200~346℃ 사이에서 완전탈수 되었으며 단사정계 결정이 무정형의 무수염으로 구조변화 한다. 이들 무수물은 380~600℃ 사이에서 R_2O_2CO_3로 상변화가 생기며 600~885.5℃에서 R_2O_2CO_3 및 RO_2CO_3는 희토류 산화물로 분해되며 무수염 착물은 2단계 분해 반응한다. 각 전이온도와 희토류원소의 원자번호는 일치하지 않을 것으로 생각되며 이런 사실은 각 전이 온도에서 희토류-옥살산 착물의 구조변화는 수화수정도와 희토류원소들의 고유특서에 의존할 것으로 보인다. The complexes of the rare earth oxalate hydrate were synthesized by coprecipitation method at room temperature. These complexes have the general formula, R)2(C)2O_d)_3XH_2), whilst cerium salt is Ce (C_2O_4)_2 10H_2O at 80℃. The structures of lanthanide oxalate hydrates have been investigated by differential thermal analysis (DTA), thermogravimetric analysis (TGA) and X-ray diffraction method. The TGA results were similar in all of the lanthanides, DTA results were almost entirely different according to the heating conditions. Changes of the structure of these oxalate complexes ignited at each transition temperature, have been discussed by X-ray diffractometry and the analytical method of electron microscope. The lanthanide complexes lost water in air at the range of 98.6~267.0℃, and the anhydrous salt was stable at the range of 200.3~346.7℃. These complexes decomposed and stable residues are formed at the following temperatures : lanthanium : 428.57℃, cerium : 380℃, praseodymium : 573.3℃. Neodymium : 536℃, samarium : 600℃, curopium : 524℃, dysprosium : 559.4℃ and holmumiu : 400.7℃, respectively. These residues were R)2O)2CO_3 or RO_3CO_3 in air, at 600~885.5℃, the rate earth oxycarbonates have begun to decompose into the rare earth oxides and the anhydrous complexes are broken down into two steps. The rare earth oxalate hydrate complexes are monoclinic and anhydrous complexes belong to the amorphous system. We have been thought that atomic numbers of rare earth elements were no accord with each transitional teperatures.

D.L-Mandelato Zirconium(Ⅳ) Complex의 物理的 特性과 加熱條件에 따른 構造變化

丁梧鎭,조경호,문경찬 조선대학교 기초과학연구소 1983 自然科學硏究 Vol.6 No.1

The dl-monomandelate zirconium(Ⅳ) and dl-tetramandelato zirconium(Ⅳ) complexes were synthesized from ZrOCl_2, 8H_2O and it was identified by UV-spectrum, IR-spectrum and element analysis, respectively. These transitional state and determination of structures according to heating curves were identified by aalytical methods of electron microphotograp and X-ray diffractiometry. The results obtained are as follows: 1) The dl-monomandelato zirconium(Ⅳ) complex obtained from the result of elements analysis for complexes synthesized was analyzed; H=3.60%, C=37.66% and Zr=31.03%. respectively and the dl-tetramandelato zirconium(Ⅳ) complex; H=4.153% C=55.23% and Zr=13.09%, respectively. 2) The dl-tetramandelato zirconium(Ⅳ) complexes were appeared with symmetric carbonyl streching mode from 1500 to 1700㎝^-1 and this symmetric carbonyl streching mode means the presense of coordinate bonding between Zr and carboxylic radical. 3) The mode of dl-monomandelato zirconium(Ⅳ) complex has asymmetrical peak, and this means the state for coordinate bonding of Zr-coo-but dl-tetramandelato zirconium(Ⅳ) complexes have symmetric peak in the range of 1000 to 1500㎝^-1 and this peak means the presence of more than one kind of zirconium carboxyl bond. 4) The dl-mono and tetramandelato zirconium(Ⅳ) complexes are formed in rtrong absorption band at 1360㎝^-1, and this values are shifted with respect to 1385㎝^-1 of the dl-mandelic acid, and complex compound synthesized from state of acetonitrile solution, is formed with strong carboxyl(vsy) band of absorption at 1360㎝^-1 and 1650㎝^-1, respectively. 5) The vcoo(sy) band of absorption at 1360~1385㎝^-1 range means to be eight coordinate complex and frequency of this range have vcoo characterics of structure. The weak band of absorption of the 2700㎝^-1 show the structure of coordinate bonding and this band have the typical harmonic vibration structure of O-H-O bonding. 6) The dl-mandelato zirconium(Ⅳ) complex in NH_4OH solution exhibits the maximum absorbany at 255mm. The maximum molar absorptivity of^-4 M dl-mono and tetramandelato zirconium(Ⅳ) complex have 0.54×10^4 and 1.2×10^4, respectively. 7) The white products (synthetic complex) precipitated from aqueous solution is polymeric with hydrogen bonding and this complexes are also insoluble in organic solvent as C_6H_6, C_2H_5OH, DMSO, and CH_3OHㆍㆍㆍetc. but is soluble in NH_4OH 8) The dl-mono and tetramandelato zirconium(Ⅳ) complex exhibit the endothermic peak of dehydration at 218.75℃ and 209.4℃, respectively. and exhibit the exothermic peak of decomposition for H_2O and CO at below 600℃ and 1050℃ in air calcination, respectively. 9) The synthetic complexes are formed with exothermic peaks transed from ZrO_2-monoclinic system to ZrO_2-tetragonal system at 1250℃ in air calcination. 10) The synthetic complexes have amorphous at below 110℃, and are appeared with ZrO_2-monoclinic systems in air calcination, respectively. If synthetic complexes are heated at 970℃ and 110℃ in air calcination, respectively. The clear crystalline structures of ZrO_2-monoclinic system are identified by X-ray diffractiometry and analytical method of electron microscope. and intensities of X-ray diffraction patterns are increased more trikis complex compound than mono complex.

중성 운반체 선택성 막전극법에 의한 우라늄 금속의 연속정량

정오진,정경훈,김삼혁 조선대학교 환경연구소 1998 環境硏究 Vol.14 No.1

The equipments with which selective ions were able to determinated by ion selective membrane electrode method have been designed with the simole electronic circuits. Having made the selective neutral carrier membrance electrodes with PVC matrix, the response potentials of 〔UO^2+_2〕 were measured with the selective membrance electrode and all of equipments and treatment of data amalysis were operated, and obtained by using the personal computer programs. The neutral carrier membrane electrodes were made by mixing the neutral carriers (macrocyclic compounds and Cryptand), plasticizer(Aliquart 336, TOPO, and TBP) and matrix(PVC). These neutral carrier membrane electrodes showed a linear potential response to the activities of UO^2+_2)(10-2-10-6M). The neutral carrier selective membrane electrodes for UO^2+_2 and equipment for analysis of selective ions mentioned above were stable and reproducible for a long time use, and the selective coefficients for 〔UO^2+_2〕 were increased in proportion to the formation constants of metal complexes with neutral carrier ligands.

특집 EPR제도 시행 -EPR제도 도입 운영방안

정오진 (사)한국포장협회 2002 包裝界 Vol.106 No.-

Synergistic Effect on the Photocatalytic Degradation of 2-Chlorophenol Using $TiO_2$Thin Films Doped with Some Transition Metals in Water

정오진,Jeong, O Jin Korean Chemical Society 2001 Bulletin of the Korean Chemical Society Vol.22 No.11

The metallorganic chemical vapor deposition (MOCVD) method has been used to prepare TiO2 thin films for the degradation of hazardous organic compounds, such as 2-chlorophenol (2-CP). The effect of supporting materials and metal doping on the photocatalytic activity of TiO2 thin films also has been studied. TiO2 thin films were coated onto various supporting materials, including stainless steel cloth(SS), quartz glass tube (QGT), and silica gel (SG). Transition metals, such as Pd(II), Pt(IV), Nd(III) and Fe(III), were doped onto TiO2 thin film. The results indicate that Nd(Ⅲ) doping improves the photodegradation of 2-CP. Among all supporting materials studied, SS(37 ${\mu}m)$ appears to be the best support. An optimal amount of doping material at 1.0 percent (w/w) of TiO2-substrate thin film gives the best photodegration of 2-CP.

陰 Ion 交換樹脂에 依한 稀土類元素의 溶離行動에 關한 硏究

정오진,김일두,이계수,차기원,Oh Jin Jung,Il Doo Kim,Gyou Soo Lee,Ki-Won Cha 대한화학회 1984 대한화학회지 Vol.28 No.1

DTPA 용리액의 pH와 농도를 변화시키면서 음이온 교환수지관을 이용해서 희토류 원소들을 분리하는 연구를 하였다. 희토류 원소들의 가장 좋은 분리조건은 0.025M DTPA, pH 8.35이 있었으며 희토류 원소들의 용리순서는 Sm을 제외하고 희토류 원소들의 원자번호 순서와 일치하였다. 0.025M DTPA, pH 8.35에서 분리한 인접 희토류 원소들의 분리값은 3.03~1.25이었으며 그중 Ce/Pr이 3.03으로 최대값을,Eu/Gd은 최소값을 각각 갖는다. 0.025M DTPA 희토류 원소들을 용리하였을 때, pH 8.0~8.6의 넓은 범위에서 비교적 좋은 분리현상을 보였다. The separation of the rare earth elements with diethylene triamine N, N, N', N', N"-pentaacetic acid (DTPA) as eluent was carried out at different pH and concentrations by using anion exchange resin column. The rare earth elements were absorbed on the upper of the resin column and the best condition of the separation behavior was 0.025M of DTPA at pH 8.35. The elution order of the rare earths was in the order of the atomic number of the rare earth elements except samarium. The resolution of adjacent rare earth elements that have been separated with 0.025M-DTPA as eluent, was from 3.03 to 1.25 at pH 8.35. Resolution of Ce-Pr was maximum value in 3.03 and Eu-Gd was minimum in 1.25 at condition mentioned above, respectively. The resolution of rare earth elements separated with 0.025M DTPA eluent was very good at pH range of 8.0~8.6.

光州地方의 土壤과 水分의 有機鹽素劑 殘留 濃度에 關한 硏究

丁梧鎭 朝鮮大學校 1977 綜合論文集 Vol.1977 No.-

In this paper, gas chromatographic determination was made on the residual concentration of organochlorine pesticides of soils and water collected from Kwangju area from March 1976 to October 1976 Having the samples been absorbed with Florisil (60~100mesh) and Wakogel S-1 (60~80mash), then pretreated with n-hexane, dichloromethane and nitril acetate (5:2:1) and the concentration of the organochlorine pesticides was detected by gas chromatogram of Gas Chromatograph (Hitachi Model 063) equiped with ??Ni-E.C.D The results obtained are 1. The absorption ratio and the collection ratio of the residual organochlorine pesticides were above 90% respectively. 2. In the soil more organochloride was detected than in water. 3. The residaul concentration of pesticides was the maximum from July to November and the least from March to May. 4. α-BHC was the most abundant in the ratio of each BHC isomer to the total BHC. γ-BHC the next then β-BHC and δ-BHC.

중성 운반체 선택성 막전극법에 의한 우라늄 금속의 연속정량

정오진,정경훈,김삼혁 조선대학교 환경공해연구소 1998 環境公害硏究 Vol.14 No.-

The equipments with which selective ions were able to determinated by ion selective membrane electrode method have been designed with the simole electronic circuits. Having made the selective neutral carrier membrance electrodes with PVC matrix. the response potentials of ??O^(2+)_(2)??were measured with the selective membrance electrodes and all of equipments and treatment of data amalysis were operated, and obtained by using the personal computer programs. The neutral carrier membrane electrodes were made by mixing the neutral carriers (macrocyclic compounds and Cryptand), p1asticizer(A1iquart 336, TOPO, and TBP) and matrix(PVC). These neutral carrier membrane electrodes showed a linear potential response to the activities of UO^(2+)_(2)(10-2-10-6M). The neutral carrier selective membrane electrodes for UO^(2+)_(2) and equipment for analysis of selective ions mentioned above were stable and reproducible for a long time use, and the selective coefficients for ??O^(2+)_(2)??were increased in proportion to the formation constants of metal complexes with neutral carrier ligands.

DBC-희토류금속들의 거대고리 착물형성에 관한 연구

정오진,송기둥,김호두,이용두 조선대학교 기초과학연구소 1985 自然科學硏究 Vol.8 No.1

The macrocyclic ligands of the dibenzo-18-crown-S(DBC) was synthesized from pyrocatechol and bis 1.1-dibromo ethane. The determination of stability constant, mole ratio, melting point and structure of solid type land calculation of thermodynamic function (△S, △H) of DBC complexes were investigated. The compound of DBC ligands with nitrate salt of rare earth element was formed 1 : 1 complexes as mole ratio in N, N-dimethyformamide. From those results, it was found that stability constant of the complexes with affects on the kind of anions. The stability constant and melting point of these complexes formed were 4.95 and 298℃ respectively.

Destruction of 2-Chloriphenol from Wastewater and Investigation of By-products by Ozonation

정오진,Jeong, O Jin Korean Chemical Society 2001 Bulletin of the Korean Chemical Society Vol.22 No.8

This study investigates the ozonation kinetics of 2-chlorophenol in wastewater under acidic condition. Intermediates and by-products generated during the process were rigorously identified and quantified. The major by-products are four carboxylic acids: tartaric acid, oxalic acid, maleic acid, and hydroxymalonic acid. The generation of these organic acids is in agreement with theoretical predictions. But hydroxylated compounds are more favorable to produce than their corresponding non-hydroxylated ones. Based on the information concerning the generation of organic acids and other aromatic intermediates, the complete reaction pathways toward mineralization can be proposed and mathematically modeled. The fitted second-order rate constants are in the same order of magnitude with the results from other studies. Using these oxidation pathways and the corresponding kinetic model, by-products generated in ozonation process can be predicted. This can help in optimizing the design and operation of any subsequent treatment processes.