• 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.

• 한국전기전자재료학회논문지
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• 제17권2호
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• pp.196-200
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• 2004

Using polyimide Langmuir-Blodgett(LB) films as a tunneling harrier, we fabricated Au/Polyimide/1-layer arachidic acid/Pb structure in order to investigate electron transport properties through a junction. It was found that 9-layer polyimide LB films function as a good tunneling harrier in a study of current-voltage(I-V) chararteristics. And several peaks originating in the vibrational modes of the constituent molecules of 1-layer arachidic acid LB films were clearly observed in d$^2$V/dI$^2$- V corves.

• 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.

• 한국재료학회지
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• 제9권6호
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• pp.595-598
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• 1999

Ultra-thin films of amphiphilic Squarylium dye were prepared on the hydrophilic glass substrate by Langumuir-Blodgett(LB) technique. From the measurement of the surface pressure-area($\pi$-A) isotherm at air-water interface, it was found that amphiphilic Squarylium dye can form the stable monolayers. Using the LB technique, the Z-type monolayer assembly can be obtained. The amphiphilic Squarylium dye LB films exhibit λ\ulcorner at 684nm. The absorption is significantly red-shifted from solution of amphiphilic Squarylium dye(637nm in chloroform), suggesting that the Squarylim chromophores form J-aggregate in the LB film.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 하계학술대회 논문집 C
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• pp.1196-1198
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• 1995

In this paper, stability improvement of fragile LB films was attempted by monolayers at the air-water interface and crosslinking of the resulting LB films. The spreading polymers were synthesized by radical copolymerization of monoalkyl with oligoethyleneglycol methyl ether, and poly(allylamine) was employed as the subphase polymer. The monolayer properties have been studied by the surface pressure-area($\pi$-A) isotherms. Interaction between polymers and metal ions at the air-water interface and in their LB films were investigated. From the FT-IR(Reflection and Transmission) spectra, the formation of carboxylate ions and the relative orientation of the side chains could be confined. The monolayers were transferable on various substrates, and the resulting LB films were characterized by SEM and VIS-UV absorbance.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1989년도 추계학술대회 논문집 학회본부
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• pp.102-104
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• 1989

The characteristics of stearic acid and PDA (pentacosaDiyonicAcid) LB films were studied using the XRD spectra for regularity of layers and ellipsometer for the total thickness of multilayer films. From the experiments of varying the PH and temperature, it was found that the stability of monolayer on the water subphase was very sensitive to its PH and temperature. The optimum condition of PH for the stable stearic acid LB film was 6$\sim$6.5. The PDA LB films were stable at the lower temperature than room temperature: we obtained very uniform PDA LB films at 12$^{\circ}C$.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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• pp.352-353
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• 2007

The spectrum for $0_{\circ}$, $90_{\circ}$-polarized light coincides with the spectrum for non-polarized light and also with the spectrum was observed in the LB film deposited using a fresh solution. And, the formation and dissociation of J-aggregates, anisotropic behavior was no longer observed in the heat treated merocyanine dyes LB films. But, in the optical absorption spectra of same LB films by UV irradiation at room temperature, their were observed only dissociation of J-aggregates, that is decrease of absorbance peak without change spectral shape. On the other hand, in the case of optical absorption spectra of the LB films by the heat treatment at $70^{\circ}C$ in the air, both of the shifted absorption bands decay and a monomer absorption peak of about 530 nm appears instead.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1994년도 추계학술대회 논문집 학회본부
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• pp.225-227
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• 1994

The second-order nonlinear optical effect, especially the second harmonic generation, in Langmuir-Blodgett(LB) films have get much attention over the past few years. For second harmonic generation(SHG) of the ultrathin organic films, the multilayer structure of the film should have the noncentrosymmetric arrangements of molecules. The Langmuir-Blodgett technique can result in the production of thin films of precisely controlled dimensions and structure. In this paper, n-octadecyl 4-(4'-nitrophenylazo)-1-naphthyl ether, ONNE(azohenzene derivative), was synthesized and the optical properties of ONNE was studied. Nonccntrosymmctric Z-type LB films of ONNE were prepared and SHG intensity of the film were measured. The structural characteristics of floating monolayer(L film) and LB film of ONNE were discussed with $\pi$-A isotherm. UV-visible absorption spectroscopy and spectroscopic ellipsometry. The polarized UV-visible absorption spectroscopy and SHO intensity suggest the molecular orientation in LB film.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.1371-1372
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• 2007

In this study, in order to confirm the application possibility to the molecular electronic device, morphlogical property of the Arachidic acid was investigated. We have investigated morphology by BAM image and AFM. ${\pi}$-A curves investigated surface pressure of this LB film from liquid to solid state ranged between 40 to 45 mN/m. BAM images investigated the different states of Arachidic Acid LB film. When the surface pressure reaches at 40 mN/m, the monolayer was deposited onto the hydrophilic glass substrates by Y-type deposition. We also investigated the frequency characteristics of LB modified glass by QCM. We investigated morphology of arachidic acid by AFM. As a result, we obtained the frequency characteristic and morphology of LB films from controlling the deposited layers.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.2
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• pp.943-946
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• 2004

We have investigated to observe the photoisomerization using the mixture solutions in chloroform and LB monolayers mixed with DPPA and BASH containing azobenzene group which has reversible to cis-trans by light irradiation.. Spreading solutions for the LB films were Prepared in chloroform($5.0{\times}10^{-5}mol/L$). We investigated the photoisomerization and property of the organic ultra thin film of fatty acid containing azobenzene was Prepared on the glass plate by LB method. As a result, the absorption spectra of 8A5H and DPPA mixture of LB films was induced to photoisomerization by alternating irradiation of ultraviolet and visible light, because the condensation of pure azobenzene monolayers was loosened by the introduction of phospholipid into the monolayers, and the molecular high aggregation in pure azobenzene monolayers is also weakened by the introduction of phospholipid. We found that it was reversibly induced to cis-trans photoisomerization in a various mixture molar ratio.