요오드화칼륨 수용액의 양극산화 (제1보)

남종우,김학준,Nam, Chong-Woo,Kim, Hark-Joon 대한화학회 1973 대한화학회지 Vol.17 No.5

To investigate the mechanism of the reaction of electrolytic oxidation of iodide to iodate ions, polarization curves are determined in various kinds of solution using electrodeposited lead peroxide and platinum anodes. It was observed from the polarization curves that the limiting current is exists at concentration 1.5 M of potassium iodide, and these limiting current disappeared as potassium hydroxide was added up to concentration of 0.1 M. while in case of platinum anode, limiting current did not appear in dilute potassium iodide solution. These results are owing to the chemical reaction, $PbO_2+2I^{-}+2H^+{\to}PbO+I_2+H_{2}O$ ocurring at the surface of lead peroxide anode. Also, we studied to obtain the optimum conditions of electrolytic preparation of iodate from iodide solution using a cell without the diaphragm. The results are that; (a) addition of potassium dichromate at the anti-reducing agent is proper in concentration of 0.1 g/l, (b) electrolytic temperature is not so much effective in raising the current efficiency, (c) current efficiency is increased with current density, and (d) electrolysis is the most effective in weak alkaline solutions. 요오드화칼륨으로부터 요오드산칼륨까지의 양극산화시 그 반응의 내용을 검토키 위하여 전착과산화납 및 백금양극을 사용하여 각종 농도의 요오드화칼륨 수용액중에서 분극곡선을 측정한 결과 요오드화칼륨의 1.5M이하에서 한계전류가 존재하며 0.1M의 수산화칼륨을 가하였을때는 한계전류는 나타나지 않음을 알았다. 한편 백금양극의 경우에는 과산화납양극에서와 같이 희박한 요오드화 칼륨수용액중에서 한계전류가 나타나지 않으며 이는 과산화납양극표면에서 $PbO_2+2I^{-}+2H^+{\to}PbO+I_2+H_{2}O$와 같은 화학반응에 기인함을 알았다. 무격막전해조를 사용하여 요오드화염으로부터 요오드산염까지의 전해제조시 가장 효율적인 전해조건에 관하여서도 검토한 결과, (a)환원방지제인 중크롬산칼륨의 첨가는 0.1g/l의 농도가 적당하였으며, (b)전해온도는 전류효율에 큰 영향을 미치지 않았으며, (c)전류밀도가 증가함에 따라 전류효율은 상승하였고, (d)전해중 전해액의 액성은 약알카리성이 가장 효율적이었다.

아자크라운에테르포스피닉산에 의한 알카리 금속이온의 경쟁용매추출

남종우,정영진,양일우 ( Chong Woo Nam,Yeong Jin Chung,Il Woo Yang ) 한국공업화학회 1992 공업화학 Vol.3 No.2

아자크라운에테르가 부착된 알킬 페닐포스피닉산을 합성하여 수용액층으로부터 클로로포름층으로 알카리금속이온의 경쟁용매추출 특성을 조사하였다. 연구된 포스피닉산들은 phenylphosphinate, aldehyde 그리고 monoazacrown ether의 한 단계 반응에서 생성되는 포스피네이트 에스테르를 알카리성 가수분해시켜 좋은 수율로 합성할 수 있었다. 합성된 포스피닉산 시약을 착물화제로 사용하여 pH에 따라 수용액층으로부터 클로로포름층으로 알카리 금속이온의 경쟁용매추출 특성을 조사한 결과 이 시약들은 넓은 pH 영역에서 금속 이온을 유기용매층으로 추출해냄을 확인하였으며, pH 11인 알카리성 용액에서의 총금속이온부하는 약 75%였다. 이온의 선택성은 아자크라운에테르의 공동크기에 주로 의존하여, monoaza-15-crown-5 기를 갖는 알킬페닐포스피닉산, 2, 에서는 Na^+>>K^+>Rb^+>Li^+>Cs^+ 순이며 monoaza-18-crown-6 작용기가 있는 알킬페닐포스퍼닉산, 3, 에서는 K^+>>Rb^+>Na^+>Cs^+>Li^+ 이온의 순으로 나타났다. 아자크라운에테르포스피닉산들은 유사한 이온선택성을 지닌 크라운에테르카르복실산에 비해 보다 넓은 영역의 pH에서 알카리금속이온의 용매추출이 가능하여, 약한 산성이나 중성 수용액에서도 상당한 정도의 금속이온부하를 나타내었다. Azacrownoalkyl phenylphosphinic acids were synthesized and their competitive solvent extraction characteristics from water to chloroform layer were investigated. Phosphinic acids were synthesized in good yields by one step reaction of phenylphosphinate, aldehyde, and monoazacrown ether and then basic hydrolysis of the resulting phosphinate esters. These complexing agents revealed a wide effective pH range in extraction of alkali metal ions from water to the organic phase and total metal ion loading at pH 11 was about 75%. The selectivity of the cation extraction was determined mainly by the cavity size of the azacrown ethers, showing Na^+>>K^+>Rb^+>Li^+>Cs^+ for the alkyl phenylphosphinic acid, 2, containing monoaza-15-crown-5 and K^+>>Rb^+>Na^+>Cs^+>Li^+ for the alkyl phenylphosphinic acid, 3, containing monoaza-18-crown-6 moiety. Applicable pH range of these azacrown ether phosphinic acids in solvent extraction of alkali metal cations was wider than a crownether carboxylic acid with similar selectivity, showing considerable amount of metal ion loading in slightly acidic or neutral media.

전착과산화납양극에 의한 옥소산염 전해산화

남종우,김학준,Chong Woo Nam,Hak Joon Kim 대한화학회 1971 대한화학회지 Vol.15 No.6

In order to evaluate the mechanism of electrolytic oxidation of iodate and to determine the optimum conditions for the electrolysis, studies were made using the cells without diaphragm and the lead peroxide anode. Results are summarized as followings: 1) Current density vs. anode potential curve by lead peroxide electrode had the different limiting current densities from platinum electrode and was more positive than platinum electrode. 2) Additions of potassium bichromate in the electrolyte contribute to maintain high current efficiency. 3) In the acid and alkaline regions, the current efficiencies decreased by reduction of iodate and discharge of hydroxyl ion, so maximum current efficiency was shown at pH 7. 4) Higher current density lowered the current efficiency in the region of 60-80% conversion of iodate. 5) Influence of the conversion on current efficiency in the region of 60-80% conversion of iodate.

電着過酸化鉛陽極製造에 關한 硏究

남종우,김학준,Nam, Chong-Woo,Kim, Hark-Joon 대한화학회 1970 대한화학회지 Vol.14 No.3

Electrodeposition of lead peroxide on the graphite core was studied. The results are following; 1) At more noble potential than 1.6V vs. S.C.E. and lower temperature than $40^{\circ}C$, $PbO_2$ deposited current efficiency is increased but deposited layer falls off easily from graphite core. 2) Oxygen overvoltage of $PbO_2$ deposited layer on the graphite core is largely with increasing $PbO_2$ depositing anodic potential and with lowlying electrolytic temperature. 3) To obtain the $PbO_2$ deposited layer without falling off from the graphite core, it is necessary to change the electrolytic conditions, anodic potential and electrolytic temperature, in four stages successively.

二酸化鉛 陽極에 의한 鹽素酸나트륨 電解製造에 있어서 電解條件 및 電流效率에 관한 硏究

남종우,Nam Chong Woo 대한화학회 1969 대한화학회지 Vol.13 No.2

On the electrolytic preparation of sodium chlorate, lead dioxide anode, instead of graphite was tested to find out the characteristics for current efficiency and life in various conditions. The results obtained are summerized as follows; 1. The current efficiency is slightly increased with the anode current density, until 25A/$dm^2$ 2. The higher the current concentrations. the lower current efficiencies are observed, particularly in case of both not-adding the potassium dichromate and large current concentration of more than 50A/l 3. The current efficiency may be improved linearly as the both temperature is raised.

요오드화칼륨 수용액의 양극산화 (제2보)

남종우,김학준,Nam Chong Woo,Kim Hark Joon 대한화학회 1974 대한화학회지 Vol.18 No.5

저자들에 의해서 이미 보고되어 있는 요오드화염으로부터 요오드산염$(I^-{\to}{IO_3}^-)$ 및 요오드산염으로 부터 과요오드산염$({IO_3}^-{\to}{IO_4}^-)$까지의 전해결과를 참작하여 무격막 전해조와 이산화납양극을 사용하여 요오드화염으로부터 과요오드산염$(I^-{\to}{IO_4}^-)$을 직접 전해제조하기 위한 최적 전해조건에 관하여 검토하였다. 0.5g/l의 환원방지제인 중크롬산칼륨을 함유함 1몰의 요오드화칼륨 수용액을 15A/$dm^2$의 양극전류밀도와 $60^{\circ}C$</TECX>의 전해온도에서 전해한 결과, 요오드화칼륨으로 부터 과요오드산칼륨까지의 변화율 98%에서 전류효율이 84%이었다. 또한 각종 전해액중에서 이산화납 양극에 의한 분극곡선으로 부터 전극반응의 내용도 설명하였다. Direct electrochemical preparation of periodate from iodide $(I^-{\to}{IO_4}^-)$ was investigated using a none-diaphragm cell and lead dioxide anode. The direct electrolytic conditions were combinations of the respectively results on the processes of iodate from iodide$(I^-{\to}{IO_3}^-)$, and periodate from iodate$({IO_3}^-{\to}{IO_4}^-)$ which were reported by the author, previously. The optimum condition was achieved when 1.0 M potassium iodide solution containing 0.5 g/l potassium dichromate as an anti-reducing agent was electrolyzed at anodic current density of $15{\AA}/dm^2$ and electrolytic temperature of $60^{\circ}C$</TECX>. Under such a condition, the current efficiency was found to be 84 % at 98 % conversion of iodide to periodate. The explanation of electrode reaction was also given a consideration based on the polarization curves at lead dioxide anode in various electrolyte solutions.

모노아자크라운에테르 기능기를 가진 생리활성 포스피네이트 유도체의 합성

남종우,정영진,양일우,Nam Chong-Woo,Chung Yeong-Jin,Yang Il-Woo 대한화학회 1993 대한화학회지 Vol.37 No.1

모노아자크라운에테르 기능기를 분자내에 갖는 4종의 새로운 포스피네이트 유도체들을 합성하고 그들의 생리활성을 조사하였다. 생리활성 포스피네이트 유도체들의 합성은 페닐포스피네이트를 알데이드 및 모노아자크라운에테르와 한 단계로 반응시켜 61~72%의 비교적 높은 수율로 이루어질 수 있었다. 합성된 화합물들의 생리활성은 수컷의 생쥐에 대한 복강주사로 검사하였으며, $LD_{50}$ 값이 65~90mg/kg으로서 크라운에테르 기능기가 부착되면 단순한 페닐포스피네이트에서 보다 독성이 현저히 증가됨을 나타내었다. 모노아자-15-크라운-5를 부착한 화합물과 모노아자-18-크라운-6을 부착한 화합물의 고리 크기에 의한 독성차는 현저하지 않았으나, 에스테르기의 종류에는 다소 영향을 받아 올틸 또는 프로필 포스피네이트 유도체들이 에틸 포스피네이트 유도체에 비해 독성이 높게 나타났다. Four kinds of new phosphinate derivatives with a pendant monoazacrown ether were synthesized and their biological activities were tested. These biologically active phosphinates were synthesized in relatively good yields (61∼72%) by one step reactions of phenylphosphinate with aldehyde and monoazacrown ether. Toxicity of these compounds was tested by intraperitoneal injection of the compounds to male mouse and revealed $LD_{50}$ value of 65∼90 mg/kg, which showed enhanced toxicity by attachment of a pendant azacrown ether to a simple phenylphosphinate structure. Although the ring size effect of the pendant crown ethers, (monoaza-15-crown-5 and monoazo-18-crown-6), beening negligible, the identity of the ester functional group in the phosphinate structure exerted sizable influence on toxicity. Thus, phosphinate derivative with octyl or propyl ester group showed somewhat higher toxicity than that with ethyl ester group.

전착과산화납양극에 의한 황산염. 전해산화시의 전해온도의 영향

남종우,김학준,Chong Woo Nam,Hak Joon Kim 대한화학회 1971 대한화학회지 Vol.15 No.5

In the electrolytic preparation of persulphate from sulphate solution, the current efficiency decrease with temperature increase at the platinum anode. But in case of electrodeposited lead peroxide anode, the current efficiency increase with temperature of the solution. The reason seems to be that the ozone formation is faster in platinum anode than in lead peroxide as temperature increase.

전극재료의 개발 현황

남종우 ( Chong Woo Nam ) 한국공업화학회 1995 공업화학 Vol.6 No.3

Cyclitol 유도체 합성에 관한 연구 (제3보)-myo-Inositol의 전해 산화-

손주환,남종우,김유옥,Joo Hwan Sohn,Chong Woo Nam,Yu Ok Kim 대한화학회 1971 대한화학회지 Vol.15 No.3

To obtain the various kinds of inosose stereomers, the process of electrochemical oxidation is more effective than chemical oxidation of myo-inositol. So that myo-inositol aqueous solution was electrolyzed by platinum and lead peroxide anode to confirming the occurrence of electrochemical oxidation. The result is that myo-inosose-2 is producing with high yield comparatively by electrolytic oxidation of myo-inositol. Also we studied about the relation between the electrolytic current efficiency and electrolytic temperature and anodic current density. The current efficiency is rising with lowering of electrolytic temperature identically in both anode such as platinum and lead peroxide and also rising with increasing of anodic current density in platinum anode, but inversely in lead peroxide.