• 한국응용과학기술학회지
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• 제14권3호
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• pp.55-61
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• 1997

Maxwell displacement current(MDC) measuring technique has been applied on the study of monolayers of polyamic acid containing p-cyanoazobenzene. 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 $140{\AA}^2$ and $100{\AA}^2$. Maxwell displacement currents were investigated in connection with 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.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 하계학술대회 논문집
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• pp.503-506
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• 2000

Molecular switching in azobenzene mixed monolayers on a water surface was investigated by means of Maxwell displacement current(MDC) measurement. It was found that the change in the vertical component of the dipolemoment of the mixed monolayer during visible light irradiation was almost the same as that flowing during UV light irradiation. Also MDC was generated but it depended on the molar ratio. As a result. It's phtoisomerization progressed by 8A5H in mixed films.

• 한국응용과학기술학회지
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• 제28권2호
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• pp.213-218
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• 2011

Displacement current measuring technique has been applied on the study of polyamic acid monolayer containing p-nitroazobenzene. The displacement current was generated from monolayer on the water surface by monolayer compression and expansion. Maxwell displacement current(MDC) was generated when the area per molecule was about $200{\AA}^2$ and $70{\AA}^2$. Maxwell displacement currents were investigated in connection with 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. The monolayer surface morphology of the LB film have been measured by Atomic Force Microscope(AFM). As a result, we confirmed that the microscopic properties of LB film by AFM showed the good orientation of monolayer molecules and the thickness of monolayer was 3.5-4.1nm.

• 한국응용과학기술학회지
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• 제16권3호
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• pp.193-198
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• 1999

Maxwell displacement current(MDC) measuring technique has been applied on the study of monolayers of fatty acid. 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 $130{\AA}^2$. MDCs were investigated in connection with monolayer compression cycles. It was found that the current pulses were generated over the entire range of molecular area, and the maximum of MDC appeared at the molecular area just before the initial rise of surface pressure in compression cycles. We investigated the change in absorption spectra of the fatty acid(8A5H) monolayer LB film due to cis-trans photoisomerization. It was found that the absorption spectrum of the 8A5H LB film was induce to photoisomerization by alternate irradiation with UV and visible light irradiation.

• 한국응용과학기술학회지
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• 제14권2호
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• pp.35-40
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• 1997

The organization of phospholipid monolayers and their monolayers mixed with fatty acid containing azobenzene on the water surface was investigated by means of the displacement current measurement method. The phase transition from the gaseous phase to the gaseous-fluid phase which accompanies the polar ordering of phospholipid molecules was detected in the range of immeasurably low surface pressure. The molecular area which gives the onset of the transition was determined for phospholipid monolayers. The Maxwell displacement current(MDC) pulses were generated across mixed monolayers due to the photoisomerization of fatty acid containing azobenzene by alternating irradiation of ultraviolet and visible light, because the condensation of pure azobenzene monolayers was loosened by the introduction of phospholipids into the monolayers. The displacement currents generated during light irradiation were also investgated in connection with 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.

• 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.

• 한국응용과학기술학회지
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• 제32권3호
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• pp.522-527
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• 2015

변위전류 측정법을 L-${\alpha}$-dilauryl phosphatidylcholine(DLPC) 단분자 막의 연구에 적용하였다. 변위전류는 물 표면에서 DLPC 단분자 층에서 압축과 확장에 의해 발생되었다. 맥스웰 변위전류(MDC) 발생은 분자 당 점유면적 $200{\AA}^2$ 에서 $40{\AA}^2$에 대하여 관찰하였다. 맥스웰 변위전류는 단분자 층의 압축 사이클에 대해 조사하였으며, MDC의 최대 값은 압축 사이클의 표면 압력이 처음 상승하기 바로 직전의 분자당 점유면적에서 나타나는 것을 알 수 있었다. LB막의 단분자층 표면 형태는 원자힘 현미경(AFM)으로 측정하였다. 결과적으로, AFM 이미지에 나타난 LB막의 특성은 단분자 층의 배향이 좋았으며 단분자 층의 두께는 약 5~10 nm였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1996년도 춘계학술대회 논문집
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• pp.6.1-10
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• 1996

Starting from the Debye theory of rotational Brownian motion equation, we derive an expression for explaining the generation of Maxwell displacement current (MDC) across single monolayers on a material surface. The orientational order parameter and the dielectric relaxation the of monolayers are derived. Based on fille analyses developed here, we examine the MDC across phospholipid monolayers with thermal stimulation due to the change in the spontaneous polarization, and the generation of MDC from 4-cyano-4\`-5-alkayl-biphenyl(5CB) Langmuir-film at the onset of transition by monolayer compression

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 하계학술대회 논문집
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• pp.475-478
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• 2000

Maxwell displacement current(MDC) was generated when the area per molecule was about 140${\AA}$$^2$and 100${\AA}$$^2$. MDC were investigated in connection with monolayer compression cycles. It was found that the maximum of MDC appeared at the molecular area just before the initial rise of surface pressure in compression cycles. The absorption spectra of polyamic acid containing p-methoxyazobenzene in a mixture of N,N-dimethylacetamide(DMAc) and benzene(1:1 by volume) solution was induced photoisomerization by UV and visible light irradiation. The precursor LB film was heated in a vacuum dry oven at 120$^{\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.

• 한국응용과학기술학회지
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• 제26권2호
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• pp.224-231
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• 2009

Techniques measuring Maxwell displacement current (MDC) and LB films surface measuring technique have been applied to the study of monolayers of polyamic acid containing azobenzene. MDCs was generated from monolayers on the water surface by monolayer compression and expansion. It was generated when the area per molecule was about $103{\AA}^2\;and\;78{\AA}^2$ just before the initial rise of the surface pressure during the 1st and 2nd mixed monolayer compressions cycle, respectively. It was the maximum of MDCs appeared at the molecular area just before the initial rise of surface pressure in compression cycles, and we have found that the increase of aggregations causes the noticeable increase of the surface roughness.