• Journal of the Korean Applied Science and Technology
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• v.11 no.2
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• pp.151-155
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• 1994

Polyamic acid alkylamine (N, N-dimethylhexadecylamine)(PAAS)염을 합성하여 그 합성여부를 확인하였으며 PAAS염의 Langmuir막의 ${\pi}-A$ 등온선 및 표면 전위 특성 등을 조사 하였다. Langmuir-Blodgett법에 의하여 PAAS염의 LB막을 여러종류의 기관에 누적하였으며 누적여부를 자외선 흡수 스펙트럼 및 적외선 투과 스펙트럼을 이용하여 조사하였다. 그리고 PAAS LB막을 열처리에 의하여 이미드(imide)화시켜 폴리이미드 LB막을 제조하였으며 그 이미드화 여부를 자외선 및 적외선 스펙트럼을 이용하여 조사하였다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1996.05a
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• pp.38-42
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• 1996

The pressure-area isotherm of monolayer at the air-water interface were obtained and the LB films were fabricated onto a quartz slides and quartz crystal by conventional Langmuir-Blodggett(LB) method. The UV absorption spectra of Langmuir-Blodggett(LB) film on quartz slides and spectrum of monolayer formed on quartz crystal have been measured. The photoisomerization of the long-chain fatty avid containing azobenzene were obtained by the application of UV and visible light. The reversibility of photoisomerization were more clear difference when the number of C$\_$n/ increased. At the pressure-area isotherms, the value of surface pressure increment were decreased when the number of C$\_$n/ increased, A surface pressure of 20mN/m was obtained as a proper one for a film deposition. The photoisomerization at LB films were also obtained by application of UV and visible light. So the LB film of long-chain fatty acid containing azobenzene has possibility to being applies to functional molecular devices such as photomemory and light switching.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.40 no.5
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• pp.489-495
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• 1991

In this paper, we study the electrical conduction mechanism in Langmuir-Blodgett(LB) ultra thin films for which the LB device has a metal/LB films(TCNQ)/metal sandwich structure. Our experiments show that the current at the LB device does not depend on the temperature at below 0 C. This phenomena confirm that the electrical conduction current is a tunnel current inherent to ultra thin films. However, the current depends upon the temperature near the room temperature. This phenomena indicates the electeical conduction current is a Schottky current inherent to ultra thin films.

• Proceedings of the KIEE Conference
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• 2000.11c
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• pp.458-460
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• 2000

We attempted to fabricate polyurethane derivatives (PU-CN, PU-DCM) LB films by using LB method. Also, we investigated the monolayer behavior at the air-water interface by surface pressure-area ($\pi$-A) isotherms. And, the surface morphologies and the physicochemical properties of LB films were investigated by atomic force microscopy (AFM) and UV-vis spectroscopy, respectively. Also, the electrical properties of polyurethane derivatives LB films were investigated by using the conductivity, the dielectric constant and activation energy. In the surface morphologies, physicochemical, electrical properties of polyurethane derivatives LB films, the properties is different as to the Polyurethane derivatives, it is considered that this phenomena could be described by the difference of lumophore pendant which was adhered at PU main chain.

• Proceedings of the KIEE Conference
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• 1997.07d
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• pp.1333-1335
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• 1997

We have made disperse diazo black D(DBD) thin films using Langmuir-Blodgett(LB) and vacuum-evaporation technique. Physical and optical properties of the films were investigated. Solution was made with a concentration of $10^{-3}mol/{\ell}$ using chloroform. Moving wall apparatus, (NL-LB140S-MWC) was employed to make the LB films. X,Y and Z-type LB films were manufactured and studied UV/visible absorbance spectra and morphology of surface using atomic force microscopy(AFM). Vacuum-evaporated DB D thin films were made at a pressure of $10^{-5}$ torr. The absorption peaks were observed at 200 and 400 nm in the LB films and vacuum-deposited films. We have also studied photoluminescence spectrum of the DBD films.

• Proceedings of the KIEE Conference
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• 1997.07d
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• pp.1244-1246
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• 1997

In conducting systems based on Langmuir - Blodgett (LB) films, tetracyanoquinodimethane(TCNQ) derivatives have been extensively studied as electron acceptor molecules. We have fabricated N-docosyl N'-methyl viologen diTCNQ (DMVT) anion radical LB film and investigated the FT-IR, ESR, and AFM images as the optical, magnetic properties and morphology of the LB film. We have measured in-plane electrical conductivity with number of layers. The in-plane conductivities are approximately $10^{-7}{\sim}10^{-6}\;S/cm$.

• Proceedings of the KIEE Conference
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• 1997.07d
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• pp.1247-1249
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• 1997

Langmuir-Blodgett(LB) method is one of the ways of fabricating organic ultra thin films. It is well known that It has the advantage to control the alignment and orientation of the molecules in the films. Metallo-phthalocyanines (MPcs) are sensitive to electron affinitive toxic gaseous molecules, such as $NO_2$, NO, $SO_2$. In this study, thin films of octa-dodecyloxy copper-phthalocyanine were prepared by LB method and characterized by using UV/Vis absorption spectroscopy and ellipsometry. Optimal transfer condition of LB films was investigated and preliminary results of current-voltage (I-V) characteristics of these films exposed to $NO_2$ gas as a function of film thickness.

• YAKHAK HOEJI
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• v.40 no.3
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• pp.343-346
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• 1996

The influence of LB20304a, a new fluoroquinolone antibiotic agent, on microflora of caecum in mice was compared with those of ciprofloxacin and piperacillin after administration of drugs for 5 days. Selective medium (CCFMA) was used for the isolation of Clostridium difficile from the specimens of mouse caecum. The emergence of C. difficile in mouse caecum induced by LB20304a was lower than that by ciprofloxacin or piperacillin at day 1 and day 7 after completing administration of drugs.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.11a
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• pp.317-319
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• 2000

We fabricated the QCM with Langmuir-Blodgett(LB) film deposited at the different subphase pH and investigated the resonant frequency response by the injection of organic gas response. In the $\pi$-A isotherms, the monolayer on the air/water interface had different limiting area per molecule and showed more condensed status as increasing the subphase pH. When palmitic acid LB film was deposited on the QCM, the resonant frequency shift was proportional to the deposited layer and had more resonant frequency shift in the case of the higher pH range as expected. In the resonant frequency for the injection of organic gas, it has been improved in the case of LB film fabricated at the lower subphase pH range and dependant upon the molecular weight of organic gas.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1997.11a
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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.