• 한국응용과학기술학회지
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• 제30권4호
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• pp.754-760
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• 2013

순환전압전류법에 의한 인지질(sphingomyelin, SP)과 polyamic acid(PAA) 혼합물의 농도(몰비 1:1, 2:1 및 3:1)를 변화시켜 혼합단분자 LB막에 대한 전기화학적 특성을 조사하였다. SP과 PAA 혼합물의 단분자 LB막은 ITO glass에 LB법을 사용하여 제막하였다. 전기화학적 특성은 $KClO_4$ 용액에서 3 전극 시스템으로 측정하였다. 측정 범위는 연속적으로 1650 mV로 산화시키고, 초기 전위인 -1350 mV로 환원시켰다. 주사속도는 각각 50~250 mV/s로 설정하였다. 그 결과 SP와 PAA 혼합물의 LB막은 순환전압전류도표로부터 환원전류로 인한 비가역공정으로 나타났다. 혼합물 LB막의 혼합(SP:PAA) 몰비가 1:1, 2:1 및 3:1에서 확산계수(D)는 각각 $2.670{\times}10^{-5}$, $3.562{\times}10^{-5}$ 및 $1.005{\times}10^{-5}cm^2s^{-1}$을 얻었다.

• 한국전기전자재료학회논문지
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• 제15권8호
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• pp.695-701
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• 2002

Maxwell displacement current (MDC) measuring technique has been applied on the study of monolayers of fatty acid and polyamic acid mixture. The displacement current was generated from monolayers on the water surface by monolayer compression and expansion. Displacement current was generated when the area per molecule was about 132 $^2$and 115 $^2$just before the initial rise of the surface pressure during the 1st and 2nd mixed monolayer compressions cycle, respectively. Maxwell displacement currents were investigated in connection with mixed monolayer compression cycles. It was found that the maximum of MDC appeared at the molecular area just before the initial rise of surface pressure in compression cycles. Ultra thin film of fatty acid and polyamic acid mixture was prepared on the hydrophilic quartz plate by Langmuir-Blodgett (LB) method. The precursor LB film was heated in a vacuum dry oven at 12$0^{\circ}C$ in order to convert it into the LB film of polyimide. The absorption spectra of LB films were also induced photoisomerization by UV and visible light irradiation.

• 한국인쇄학회지
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• 제15권2호
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• pp.117-130
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• 1997

Studies have been conducted to explore thermal imidization of polyamic acid. Aromatic polyimides are well recognized as high temperature linear polymers, and polyimide are used as structural materials, fibers, and adhesive. Two different kinds of polyimide were prepared by theimidization of polyamic acid which were synthesized from 2,2-bis[4-(4-aminophenoxy)phenyl]- hexafluoropropane, 2,2-bis [4-(4-aminophenxy)phenyl] - hexamethylpropane and caprolactam and pyromelliti dianhydride under N-Methly-pyrrolidinone solvent. Polyamic acids were converted to polyimides containing imide bond by thermal imidization. The weight 50% loss temperatures of polyimide by TGA thermogram were recorded in the range of 700 ~ 720$^{\circ}$C in nitrogen gas. According, as a results, we conclued polyamic acid were cycliation after H2O molecule separationed, and this polyimide film could be used for Printed Circuit Boand.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1997년도 추계학술대회 논문집
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• pp.298-301
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• 1997

This paper describes the thermally stimulated current(TSC) measurements arachidic acid(AA) and polyamic acid alkylamine salts(PAAS) LB film, which is a precursor of polyimide(PI). The measurements were performed from room temperature to about 250$^{\circ}C$ and the temperature was increased at a rate of 0.02 $^{\circ}C$/s linearly[4]. It shows that peaks of TSC are observed at about 80$^{\circ}C$ in the arachidic acid and about 80$^{\circ}C$, 160$^{\circ}C$ in the PAAS LB films. The DSC and TGA of PAAS, arachidic acid are measure. Monolayer phases on the water subphase such as Langmuir(L) films and the phase transitions from gas phase to solid phase via liquid phase are observed using Brewster angle microscopy(BAM). BAM is also used to observe the Langemuir-Blodgett(LB) films.

• 한국재료학회지
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• 제9권1호
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• pp.65-72
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• 1999

In order to minimize flexible printed circuit(FPC), which is used in computer, communication, medical facility, aviation space industry, it is required to improve the interfacial adhesion of polymide/epoxy or polyimide/polyimide consists of FPC. In this study, it was considered to improve the adhesion strength of polyimide/epoxy joint by introducing functional group on polyimide film and improving mechanical property of epoxy. Functional group on polyimide film was introduced by changing polyimide film surface to polyamic acid in KOH aqueous solution. The optimum conditions for surface modification were the concentration of 1M KOH and treatment time of 5min. Also, the optimum adhesion strength of polyimide/epoxy joint was obtained using rubber modified epoxy and polyamic acid as a base resin and curing agent of epoxy adhesive, respectively. The degree of surface modification of polyimide film examined with contact angle measurement of FTIR, thus modification of polyimide to polyamic acid was identified. Fracture surface of plymide/epoxy joint was analyzed by scanning electron microscopy, and modified polyamic acid reimidezed to polymide as increasing curing temperature.

• 폴리머
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• 제26권5호
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• pp.634-643
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• 2002

고분자 주사슬에 벤젠과 sulfonyloxvimide moiety를 가지고 있는 polyamic acid 초박막을 LB 기법을 이용하여 제조한 다음 200 $^{\circ}C$에서 1시간 동안 열처리에 의해 감광성 폴리이미드 LB 필름을 얻었다. Polyamic acid는 THF-pyridine 공용매를 가지고 축중합에 의해 합성하였다. 모든 단량체와 고분자는 원소분석, FT-IR, $^1$H-NMR의 분광학적 측정을 통해 정량 정성분석을 행하였다. UV lithography 방법을 사용하여 금 기판 위에 제조한 감광성 폴리이미드 LB 필름의 마이크로 어레이 패턴을 제조하였다. 형성된 마이크로 어레이 패턴을 따라 두 가지의 자기조립 방법으로 단백질 cytochrome c 단분자 막을 고정화시켰다. 자기조립된 cytochrome c 단분자 막의 물리ㆍ전기 화학적 특성은 cyclic voltammetry와 AFM을 통해 조사하였으며 생물전자소자로의 응용 가능성에 대해서도 검토하였다.

• 폴리머
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• 제24권2호
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• pp.228-236
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• 2000

알킬암모늄 브로마이드로부터 몬모릴로나이트 ($Na^{+}$-MMT)를 개질하여 2종류의 polyamic acid (BPDA-PPD, BTDA-ODA/MPD)를 삽입 후, 열이미드화 반응으로부터 폴리이미드/clay 나노복합재료를 제조하였다. 제조된 나노복합재료를 XRD로 관찰한 결과, 층간에 유기물질로 치환 되어 있는 MMT에 polyamic acid를 삽입하였을 경우 치환되어 있는 알킬 암모늄 양이온의 사슬 길이에 따라 MMT의 실리케이트의 층간거리가 증가하였다. 그리고 polyamic acid (PAA)가 삽입된 MMT를 승온하여 폴리이미드 복합재료를 제조한 결과 알킬 암모늄 양이온의 사슬길이와 PAA 종류에 상관없이 실리케이트의 층간 간격이 약 13.2 $\AA$이었으며, XRD와 TEM을 통하여 폴리이미드 매트릭스 내에 몬모릴로나이트의 실리케이트층이 규칙적으로 분산되어 있는 삽입형 (intercalated ) 나노복합재료임을 확인하였다. 그리고 복합재료의 열안정성을 TGA로 관찰 결과 폴리이미드 복합재료는 순수한 폴리이미드보다 열안정성이 약간 향상됨을 확인하였다. 그리고 동적 기계적 특성을 조사한 결과 나노복합재료가 폴리이미드보다 1.2~l.8배 저장탄성율이 증가됨을 확인하였다.

• 한국재료학회지
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• 제26권9호
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• pp.478-485
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• 2016

An amide group was introduced to restrain the cohesion of silica nano-particles and copolymerized with polyamic acid. Amide block copolymers were prepared using silica and (3-mercaptopropyl) trimethoxysilane (MPTMS) with a siloxane group, using 2, 6-Lutidine as a catalyst. Amide block polymers and copolymers were synthesized via ATRP after brominating pyromellitic dianhydride (PMDA) and polyamic acid of methylene diphenyl diamine (MDA) using ${\alpha}$-bromo isobutyryl bromide. Characteristic peaks of copolymer with amide and imide groups and patterns of amorphous polymers were studied using FT-IR and XRD analyses; an analysis of the surface characteristic groups was conducted via XPS. Changes in the thermal properties were examined through DSC and TGA; solubility for solvents was also studied.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1996년도 추계학술대회 논문집
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• pp.147-151
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• 1996

Brewster angle microscopy(BAM) makes it possible to observe the monolayer states on the water subphase and the phase transitions from a gaseous phase via a expanded phase to a condensed phase. Also BAM can be used to observe the films on the solid substrate such as Langmuir-Blodgett(LB) films. In this Paper Polyamic Acid Alkylamine Salts(PAAS) was used for forming L films and LB films and $\pi$-A isotherm showed pressure of each phase. We obtained BAM images as surface pressure increased. Images of LB films were compared with data from ellipsometry which was used to measure the film thickness. Images of both L films and LB films were analyzed with computer in the point of brightness.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 추계학술대회 논문집
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• pp.53-56
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• 2000

Langmuir-Blodgett(LB) technique is the best candidate for the future molecular electronic devices. But, these molecular thin film devices require the bulk properties that are influenced by the molecular orientations. So, this is of current interest in molecular electronic device fabrications of new materials. In this study, quantitative evaluation of molecular orientation in LB films of PAAS was performed by comparing the absorption intensities of the FT-IR transmission and reflection-absorption spectra and the polarized UV/visible absorption spectra. It was found that the polar angle( $\theta$ ) of the dipole moment is about 68$^{\circ}$ and the tilting angle of the alkyl chain is about 11.5$^{\circ}$