• 공업화학
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• 제7권1호
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• pp.118-128
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• 1996

양이온성 천연 고분자 전해질인 chitosan의 수용성 유도체를 제조하기 위해 chitosan에 먼저 Schiff's base를 형성시키고, 이를 다시 환원시키는 방법으로 chitosan에 N-methyl, N-butyl, N,N-dibutyl기를 각각 도입시킨 후, NMP중에서 methyl iodide를 이용하여 4차 ammonium 기가 도입된 chitosan 유도체를 합성하였다. 이 반응에서 선택적인 N-alkyl 유도체 뿐 아니라 O-alkyl 또한 진행됨을 확인하였다. 제조한 각 4 차 ammonium기가 도입된 chitosan 유도체의 응집성능을 검토하기 위해 제지공장 폐수를 대상으로 응집실험을 행한 결과, chitosan 에서와는 달리 거의 모든 pH 영역에서 일정하게 뛰어난 투과도와 COD 제거율을 보였으며, alkyl 기의 탄소수가 증가할수록 응집능은 증가되었고 그 중에서도 N-butyl dimethyl chitosan ammonium iodide가 가장 우수하였다. 그러나 N-dibutyl methyl chitosan ammonium iodide는 오히려 chitosan 자체보다 감소하는 경향을 나타내었다.

• 약학회지
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• 제24권2호
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• pp.135-141
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• 1980

The crystal and molecular structure of 2-methyl-3-(N-trimethyl ammonium)phenol iodide, $C_{10}H_{16}NOI, was determined by X-ray diffraction method. The compound crystallizes in the orthorhombic space group $P_{na2}_{1}$ with a=13.327(3), b=12.496(3), C=7.227(2)A and Z=4. A total of 489 independent observed reflections were collected by the automated Four-circle diffractometer and was solved by heavy atom method and refined by anisotropic block-diagonal least-squares method to the R value of 0.04. The benzene ring is slightly distorted from regular hexagon. The I atom and 2-methyl-3-(N-trimethyl ammonium)phenol group is held together by van der Waals forces in the crystal. Intermolecular hydrogen bond is of the type O-H....I with the length 3.35.angs.. Apart from the hydrogen bonding system the molecules are held together by van der Waals forces in the crystal.

• 대한화학회지
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• 제56권2호
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• pp.201-206
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• 2012

The anticorrosive effect of 3-Hydroxyflavone (3HF) in combination with quarternary ammonium bromide and iodide salts (QAB and QAI) for aluminium corrosion in NaOH medium was studied at the temperature range of 303K-323K using weight loss study, potentiodynamic polarization study and impedance spectroscopic measurements. The results revealed that the inhibition efficiency increases with the inhibitor concentration and it further increases on the addition of quarternary ammonium bromide and iodide salts. The enhanced inhibition efficiency of the inhibitor in the presence of quarternary ammonium salts may be due to synergistic effect. The adsorption process of 3HF on the aluminium surface obeys Langmuir's adsorption isotherm. The mechanism of adsorption is further supported by Scanning Electron Microscopic study (SEM).

• 통합자연과학논문집
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• 제10권4호
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• pp.175-191
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• 2017

In organic chemistry amide synthesis is performed through condensation of a carboxylic acid and an amine with releasing one equivalent of water via the corresponding ammonium carboxylate salt. This method is suffering from tedious processes and poor atom-economy due to the adverse thermodynamics of the equilibrium and the high activation barrier for direct coupling of a carboxylic acid and an amine. Most of the chemical approaches to amides formations have been therefore being developed, they are mainly focused on secondary amides. Direct carbonylations of tertiary amines to amides have been an exotic field unresolved, in particular direct carbonylation of trimethylamine in lack of commercial need has been attracted much interests due to the versatile product of N,N-dimethylacetamide in chemical industries and the activation of robust N-C($sp^3$) bond in tertiary amine academically. This review is focused mainly on carbonylation of trimethylamine as one of the typical tertiary amines by transition metals of cobalt, rhodium, platinum, and palladium including the role of methyl iodide as a promoter, the intermediate formation of acyl iodide, the coordination ability of trimethylamine to transition metal catalysts, and any possibility of CO insertion into the bond of Me-N in trimethylamine. In addition reactions of acyl halides as an activated form of acetic acid with amines are reviewed in brief since acyl iodide is suggested as a critical intermediate in those carbonylations of trimethylamine.

• Bulletin of the Korean Chemical Society
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• 제32권8호
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• pp.2633-2636
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• 2011

A new type of ionic liquid based on N-(3-aminepropyl)imidazolium iodide, called IIQAI, which consists of imidazolium and quaternary ammonium salt, and APII-(hydroxyethyl, propyl, hexyl) were synthesized and used as ionic liquid in dye-sensitized solar cells. APII-hexyl is solid, whereas IIQAI, APII-(hydroxyethyl, propyl) are viscous liquids. The synthesized ionic liquid showed relative thermal stability compared to the commercial ionic liquid of DMII. Among them, IIQAI was more stable than the other ionic liquid because of the two salt groups. APII-hydroxyethyl, which contains two hydroxyl groups, showed low viscosity with good flow. New types of ionic liquids were examined by $^1H$-NMR spectroscopy, thermo gravimetric analysis (TGA). IIQAI enabled a solar energy conversion efficiency of 6.3%, which is slightly higher than that of the referenced (DMII, 6.2%).

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 1997년도 춘계학술발표회 논문집
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• pp.155-169
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• 1997

• 새물리
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• 제68권11호
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• pp.1208-1214
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• 2018

단일 스텝 스핀 코팅 (one-step spin coating) 공정은 $MAPbI_3$ 페로브스카이트 (Perovskite) 박막의 결정화가 우수하여 고효율 태양 전지 제작이 가능하다. 이 공정의 핵심은 솔벤트 증발 제어 공정을 사용하는 것인데, 이는 스핀 코팅 시 $MAPbI_3$ 의 용해도를 증가 시킬 수 있는 용매를 투입하는 (dripping) 방식이다. 본 연구에서 용매의 양, 투입속도 및 시간에 따라 생성되는 $MAPbI_3$의 특성을 분석하고, 이렇게 만들어진 박막을 이용한 태양 전지 특성을 조사하였다. $MAPbI_3$ 박막 형성을 위하여 lead iodide, methyl-ammonium iodide를 N,N-dimethylformamide에 녹이고, N,N-dimethyl sulfoxide를 첨가하여 용액을 만들었으며, 증발 제어 공정을 위한 용매로 diethyl ether (DE)를 사용하였다. DE의 투입 조건에 따라 $MAPbI_3$ 박막 형성 시 핵 생성에 차이가 생기고, 이는 $MAPbI_3$의 결정화, 밀도 및 표면 상태에 영향을 미치는 것으로 나타났으며, 이에 따라 태양 전지의 효율이 달라지는 것을 알 수 있었다. 0.7 mL의 DE의 양, 3.03 mL/sec 투입 속도, 7초(스핀 코팅 시작 후 투입시간)의 솔벤트 증발 제어 공정 결과 최대 13.74% 효율을 가지는 태양 전지 소자를 재현성 있게 관측할 수 있었다.

• 공업화학
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• 제7권5호
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• pp.1020-1026
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• 1996

천연고분자인 chitin의 탈아세틸화물인 chitosan의 유리아미노기에 알킬 길이가 다른 알데히드를 이용하여 N-alkyl chitosan 유도체를 각각 합성한 다음, 이들을 methyl iodide로 4차화시킴으로서 4차 암모늄기가 도입된 새로운 수용성 chitosan 유도체를 합성하여, 도입된 알킬기의 길이에 따른 항균성을 그람양성균인 S. aureus(ATCC 6538P)와 그람 음성균인 E. coli(ATCC 14339)에 대해서 shake flask법을 이용하여 검토하였다. 그 결과 소수성이 증대될수록 항균력은 증가하였고, 특히 그람음성균인 E. coli에 비해 그람양성균인 S. aureus에 대한 항균력이 더욱 증대됨을 확인할 수 있었다. 이는 cytoplasmic membrane의 구조상의 차이에서 기인한 것으로 생각된다.

• Bulletin of the Korean Chemical Society
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• 제33권8호
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• pp.2679-2682
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• 2012

A simple one-pot synthesis of two derivatives of 1,4-dihydropyridines has been described under reflux conditions using copper iodide nanoparticles (CuI NPs) as a catalyst in high yields. This method demonstrated four-component coupling reactions of aldehydes and ammonium acetate via two pathways. In one route, the reaction was performed using 2 eq ethyl acetoacetate while in the other one 1 eq ethyl acetoacetate and 1 eq malononitrile were used. The CuI NPs was reused and recycled without any loss of activity and product yield. It is noteworthy to state that wide range of the 1,4-dihydropyridines have attracted large interest due to pharmacological and biological activities.

• 약학회지
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• 제29권1호
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• pp.39-42
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• 1985

Betaines of bicyclic imidazo-thiazoles were synthesized by the reaction of clectrophiles such as methyl isocyanate, methyl isothiocyanate, allyl isothiocyanate and ketene with 3-methyl and 3-phenyl-5, 6-dihydroimidazo [2,1-b] thiazole. In this reaction, the methyl group which was substituted at 3-position increased the yields of the products in comparison with those from phenyl group substituted substrates. Also, the betaines reacted with methyl iodide to give imidazo-thiazolium salts which were unstable at high temperature and converted the quaternary ammonium salts of original biheterocycles.