고분자 이미다졸-금속 착제 LB막의 선책적 기체 투과성

김병주,이범종 인제대학교기초과학연구소 1999 자연과학 Vol.3 No.-

이미다졸-금속 이온구조를 갖는 고분자 Langmuir-Blodgett(LB)막을 다공성 막 필터 위에 제조하여 산소와 질소의 투과성을 이들의 캐스트 막과 비교하여 검토하였다. 양친매성 고분자 폴리(N-(2-(4-이미다졸일)에틸)말레이미드·alt-1-옥타데센)(IM-O)는 폴리(무수말레산-alt-1-옥타데센)과 히스타민의 반응으로 합성되었다. IM-O는 순수한 물 또는 금속 이온 (철(Ⅲ)과 코발트(Ⅱ)이온)하층액 위에서의 40 mN/m의 표면압력에서도 안정한 일분자막을 유지하였다. 이 일분자막은 30 mN/m의 표면 압력에서 FP-010 막 필터 위에 Y형태로 누적되었다. 이 다중막의 구조는 FT-IR을 통하여 확인하였다. LB막의 균일성과 안정성은 SEM 관찰을 통하여 간접적으로 평가하였고, 산소와 질소의 투과도는 감압법을 이용하여 측정하였다. 본 LB막들의 기체 선택성은 산소보다 질소가 약간 높게 나타났으며, 두 기체에 대하여 모두 고투과성을 나타냈다. 이들 고분자-금속 착체의 캐스트 막을 제조하여 기체 투과도를 측정한 결과 질소에 대한 선택성은 변함이 없었다. The permeability of oxygen and nitrogen was investigated from the polymeric LB films containing imidazole-metal ion complexes and compared with its corresponding cast films on porous membrane filters. The amphiphilic polymer, poly(N-(2-(4-imidazolyl)ethyl)-maleimide-alt-1-octadecene)(IM-O), was synthesized by reaction of poly(maleic anhydride-alt-1-octadecene)with histamine. Chloroform solutions of IM-O were spread on pure water and aqueous metal ions(iron(Ⅲ) and cobalt(Ⅱ)ions) and the monolayers showed high stability up to 40 mN/m against surface pressure. The monolyers of polyion-complexed polymers at the air-water interface can be transferred onto solid substrates such as a porous fluorocarbon membrane filter(FP-010) and a CaF2 plate. The Y-type deposition was found at a surface pressure of 30 mN/m. The molecular structures of LB films were investigated by means of FT-IR spectroscopy. The mechanical stability and uniformity of the LB films on FP-010 membranes were indirectly evidenced by SEM observation of the surface morphology of FP-010 membranes were indirectly evidenced by SEM observation of the surface morphology of FP-010 covered with the LB films. The permeability of oxygen and nitrogen was measured with the pressure method. The LB films showed more or less higher selectivity toward nitrogen, and high permeability was found to both the oxygen and nitrogen. The cast films of the corresponding polymer-metal complexes also showed preference to nitrogen in selectivity.

화상창상의 치유 및 반혼형성 과정에서 신경펩티드의 변화

장영철,범진식,이종욱,오석준 대한화상학회 2003 대한화상학회지 Vol.6 No.2

화상창상의 치유 및 반흔형성 과정에서 신경펩티드의 변화

장영철,범진식,이종욱,오석준 대한화상학회 2003 대한화상학회지 Vol.6 No.2

2-헵타데실-2-옥사졸린의 공기-물 계면에서의 일분자막 및 LB막 특성

황선경,이범종 인제대학교 기초과학 연구소 1999 자연과학 Vol.3 No.-

2-헵타데실-2-옥사졸린(C17-OXZ)양친매성 분자의 공기-물 계면에서의 개환 반응과 Langmuir-Blodgett(LB)막의 가교화에 대해 연구하였다. C17-OXZ는 스테아르산과 2-아미노에탄올의 탈수 및 고리화 반응에 의해 합성되었다. 일분자막의 특성은 표면압력-면적(π-A)등온선으로 확인하였다. 하층액이 산성일 때 또는 폴리알릴아민을 포함하고 있을 때 일분자막이 더욱 팽창하였다. 그러나, 알칼리 하층액에서는 순수인 경우에 비하여 π-A등온선상에 주목할 만한 변화가 관찰되지 않았다. 폴리아크릴산을 포함하는 경우에서는 더욱 팽창된 일분자막을 형성하였고 표면압력의 자발적인 증가가 발견되었다. 일분자막의 상변화는 Brewster 각 현미경(BAM)에 의하여 관찰되었다. 일분자막들은 플루오르화 칼슘기판에 누적되었고 FT-IR 분광법으로 분자구조를 결정하였다. 그 결과 옥사졸린의 개환 중합보다는 이미노 이중결합의 가수분해 반응이 우세함을 확인하였다. LB막의 안정성은 다공성 기판 위로의 누적형태를 주사 전자 현미경으로 관찰함으로써 간접적으로 평가하였다. 하층액에 폴리아크릴산을 포함하는 경우가 가장 안정된 LB막을 형성하였다. The network structures of monolayers are important for molecularly-thin films such as the LB film in order to improve the intrinsic fragility and to make their technological applications possible. In this study, we investigated the ring-opening reaction of 2-heptadecyl-2-ox-azoline(C17-OXZ) at the air-water interface and its formation of network LB films. The amphiphile C17-OXZ was synthesized via dehydration and cyclization of stearic acid with 2-am-inoethanol. Monolayer behaviors were studied at the air-water interface by measuring the surface pressure-area(π-A)isotherms. When the subphase became acidic or contained poly(allylamine), the monolayers showed more expanded phases. However, any noticeable change of the π-A isotherm was not observed in alkaline subphase compared with that of pure water subphase. When poly(acrylic acid)was dissolved in the subphase, the π-A isotherm revealed expanded monolayer and a spontaneous increase of surface presssure was found. Phase changes of the monolayers were observed by Brewster angle microscopy(BAM). The monolayers were transferred onto calcium fluoride substrates and the molecular structures were determined by the FT-IR spectroscopy. However, the competitive advantage was favored to hydrolytic reaction of imino double bond rather than the ring-opening polymerization expected from the imino nitrogn on oxazoline ring. The stability of the network film was indirectly evaluated by the SEM observation of the film morphology covered over the porous substrate. The most stable LB film was produced from the subphase containing poly(acrylic acid)

곁사슬형 Polyethylene Glycol을 가진 Adenosine Deaminase 결합체의 생화학적 특성

안치운,이범종,김동규 인제대학교 1996 仁濟論叢 Vol.12 No.2

Calf adenosine deaminase(ADA) was modified with pendant-type polyethylene glyco1(PEG) using cyanuric chloride as a coupler. Attachment of PEG to the enzyme alters the kinetic profile of the enzyme in that a decrease in the Km for adenosine. The Km value of the ADA and PEG-ADA10 were 30 μM, 25 μM against adenosine, respectively. But the PEG-ADA20 exhibited reasonable retention of catalytic activity with a increased Km, it was 50 μM against adenosine. Thermal inactivation at temperature above optima was essentially the same for the native and modified enzyme. PEG appears to have no effect on stabilizing to high temperature. This suggests that PEG attachment causes some destabilization of the adenosine deaminase structure. The electrophoretic mobility in polyacrylamide gels of PEG-ADA was severely reduced as compared to the native enzyme. Unmodified proteins show single band, whereas the modified enzyme forms a number of bands throughtout the gels. The decreased electrophoretic mobility of PEG-ADA may be due to a charge-shielding effect of the hydrophilic PEG shell surrounding the enzyme. In addition, the increased size of the adducts formed may serve to retard migration in the polyacrylamide gels. The present results show that the biochemical properties of adenosine deaminase were altered after chemical modification with PEG.

Reaction Environment Effect on Hydrolysis of Nitrophenyl Acetates by Cyclodextrins

Lee, Burm-Jong,Cho, Sung-Dae 인제대학교 1995 仁濟論叢 Vol.11 No.2

시클로텍스트린에 의한 니트로페닐 아세테이트의 에스테르 분해시에 알코올 또는 금속 이온의 존재하에서 ortho-, meta-, para-이성질체의 선택성이 크게 달라짐을 발견하였다. 메탄올 및 에탄올은 기질중 가장 활성화된 에스테르인 ortho-이성질체에 대해 시클로텍스트린과 함께 협동적 친핵체로 작용하였다. t-부틸 알코올 및 이소아밀 알코올과 같은 소수성 벌키 그룹을 갖는 경우에는 α- 및 β-시클로텍스트린의 촉매 작용을 저해하였으나 γ-시클로텍스트린은 영향을 받지 않았다. γ-시클로덱스트린에서는 기질과 알코올이 동시에 세성분의 포접 착체를 형성하는 것으로 추정된다. 알칼리 금속 이온은 기질의 분해 속도를 증가시키는 반면 알칼리 토금속 이온들은 저해 효과를 나타내었다. 알칼리 금속의 존재하에서 이성질체에 대한 선택성은 α-시클로덱스트린의 경우 ortho-〉meta-〉para-이성질체의 순이었으며, β-시클로덱스트린의 경우는 para-〉meta-〉ortho-이성질체의 순으로 바뀌었고, γ-시클로덱스트린에서는 para-〉ortho-〉meta-이성질체의 순이었다. 시클로덱스트린의 수산기와 다중 정전기적 상호작용이 가능한 경우에는 기질의 포접 결합을 입체 저해하는 것으로 판단된다. The conversion of isomer selectivity by adding alcohols or metal ions was found in the hydrolysis of nitrophenyl acetates by cyclodextrins(CDs). Low-molecular weight alcohols such as methanol and ethanol acted as nucleophile cooperatively with CDs, particularly toward ortho-isomer. Bulky alcohols such as t-butyl alcohol and isoamyl alcohol inhibited the catalytic action of α- and β-CDs, but did not in the γ-CD. A ternary inclusion complex including the alcohol and the substate was estimated in the γ-CD system. While the alkali metal ions promote the hydrolysis of the substrates, the alkali earth metal ions reduced the hydrolytic rate by CDs. The isomer selectivity in presence of the alkali metal ions was the order of ortho-〉meta-〉para-isomers in the α-CD, para-〉meta-〉ortho-isomers in the β-CD, and para-〉ortho-〉meta-isomers in the γ-CD. The multivalent ions which can form electrostatic multidentate interaction ale supposed to inhibit sterically the inclusion complexation.

Interaction of a Pyridyl-Terminated Carbosiloxane Dendrimer with Metal Ions at the Air-Water Interface

Burm-Jong Lee,Seong-Hoon Kim,Chung-kyun Kim,Hoon-Kyu Shin,Young-Soo Kwon 대한전기학회 2003 KIEE International Transactions on Electrophysics Vol.3C No.6

Monolayer Stability of Amphiphilic Poly(itaconate-methacrylate)s According to the Copolymer Composition

Lee, Burm-Jong 인제대학교 1998 仁濟論叢 Vol.14 No.1

The stabilities of the monolayers and the Langmuir-Blodgett (LB) films of amphiphilic poly(itaconate-co-metacrylate)s were evaluated according to the copolymer composition. Monooctadecyl itaconate (C18ITA) was synthesized from reaction of itaconic anhydride with 1-octadecanol. C18ITA was copolymerized with poly(ethylene glycol) (400) monomethyl ether monomethacylate (ME9) through radical polymerization with various feed ratios, and the copolymers P1, P2, and P3 having 76, 59, and 28 mole % of ME9 component were obtained, respectively. The monolayer. and LB film stabilities were estimated by the surface pressure-area isotherm and scanning electron microscopy, the stability was the order of P3〉P2〉P1. The stability was enhanced by addition of poly(allylamine) into the subphase through the polyion-complexation between carboxyl and amino groups of different polymers. Keywords: monolayer, Langmuir-Blodgett film, stability, copolymer composition

Orientation Control of Polyoxometalate Nanoparticles in Organic-Inorganic Hybrid LB Films

Burm-Jong Lee,Hee Sang Kim,Dong Ho Park,Sang Hee Nam,Yunghee Oh 대한전기학회 2004 KIEE International Transactions on Electrophysics Vol.4C No.1

Interaction of a Pyridyl-Terminated Carbosiloxane Dendrimer with Metal Ions at the Air-Water Interface

Lee, Burm-Jong,Kim, Seong-Hoon,Kim, Chung-kyun,Shin, Hoon-Kyu,Kwon, Young-Soo The Korean Institute of Electrical Engineers 2003 KIEE International Transactions on Electrophysics Vol.3C No.6

A new class of carbosiloxane dendrimer (G4-48PyP) terminated with 4-pyridylpropano I was synthesized and its possible application to functional thin films was examined through metal complexation and Langmuir-Blodgett (LB) technique. The highly concentrated periphery pyridyl groups of G4-48PyP were exposed on aq. aluminum ions at the air-water interface. The monolayers showed stability up to ca. 50 mN/m of surface pressure. When the subphase became acidic or alkaline, the monolayers changed to condensed phase. The presence of aluminum ions also caused reduction of the molecular area. The macroscopic images of the monolayers were monitored by Brewster angle microscopy (BAM) and only the images of dendrimer aggregates could be observed after the monolayer collapse. The surface images of the monolayer LB film were scanned by atomic force microscopy (AFM). The convex structures of single and aggregate molecules were directly observed. The structures of Langmuir-Blodgett (LB) films were characterized by FT-IR, UV-Vis, and X-ray photoelectron spectroscopy (XPS). The UV-Vis spectrum of the aluminum ion-complexed LB film showed additional band around 670nm, which was not found in the spectra of dendrimer itself or aq. aluminum ions. XPS spectra also supported the incorporation of aluminum ions into the LB films.