• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1996.11a
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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.

• Journal of the Korean Applied Science and Technology
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• v.32 no.4
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• pp.789-794
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• 2015

In this study, we investigated the stability with respect to the Langmuir-Blodgett(LB) monolayer films of stearic acid and phospholipid(L-${\alpha}$-dimyristoylphosphatidyl choline, DMPC) mixture. LB films of stearic acid and DMPC monolayer were deposited by the LB method on the indium tin oxide(ITO) glass. The electrochemical properties measured by cyclic voltammetry with three-electrode system in $0.05N\;NaClO_4$ solution, -0.3 V initial, 1650 mV switching potential and -1350 mV final potential. As a result, monolayer LB films of stearic acid and phospholipid mixture was appeared on irreversible process caused by the oxidation current from the cyclic voltammogram. Diffusion coefficient (D) of stearic acid and DMPC mixture(molar ratio 1:1, 1:2, 1:3) was calculated $1.4{\times}10^{-3}$, $1.7{\times}10^{-3}$ and $1.6{\times}10^{-3}(cm^2/s)$ in $0.05N\;NaClO_4$ solution, respectively.

• KIEE International Transactions on Electrophysics and Applications
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• v.3C no.6
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• pp.216-219
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• 2003

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.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.52 no.5
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• pp.201-205
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• 2003

We synthesized dendrimers containing light switchable units, azobenzene group. And the dendrimer containing 48 pyridinepropanol functional end group, which could form a complex structure with metal ions was synthesized. To apply to the molecular level devices or data storage system using Langmuir-Blodgett(LB) film, we firstly investigated the monolayer behavior using the surface pressure-area($\pi$-A) isotherms at air-water interface. And then the surface pressure shift of monolayer by light irradiation was also measured to the dendrimer with azobezene group. As a result, the monolayer of dendrimer with azobenzene group showed the reversible photo-switching behavior by the isomerization of azobenzene group in their periphery. The samples for electrical measurement were fabricated to two types which were pure dendrimer with pyridinepropanol group and its complexes with $Pt^4+$ ions by LB method. We have studied the electrical properties of the ultra thin dendrimer LB films investigated by the current-voltage(I-V) characteristics of Metal/Dendrimer LB films/Metal(MIM) structure. And we have investigated different results in the surface activity at the air-water interface as well as the electrical properties for the monolayers of pure dendrimer with pyridinevopanol group and its complex with $Pt^4+$ ions. In conclusion, it is demonstrated that the metal ion around dendrimer with pyri야nepropanol group can contribute to make formation of network structure among dendrimers and it result from the change of electrical properties. This results suggest that the dendrimers with azobenzene group and pvridinedropanol group can be applied to high efficient nano-device of molecular level.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.52 no.5
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• pp.201-201
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• 2003

We synthesized dendrimers containing light switchable units, azobenzene group. And the dendrimer containing 48 pyridinepropanol functional end group, which could form a complex structure with metal ions was synthesized. To apply to the molecular level devices or data storage system using Langmuir-Blodgett(LB) film, we firstly investigated the monolayer behavior using the surface pressure-area($\pi$-A) isotherms at air-water interface. And then the surface pressure shift of monolayer by light irradiation was also measured to the dendrimer with azobezene group. As a result, the monolayer of dendrimer with azobenzene group showed the reversible photo-switching behavior by the isomerization of azobenzene group in their periphery. The samples for electrical measurement were fabricated to two types which were pure dendrimer with pyridinepropanol group and its complexes with $Pt^4+$ ions by LB method. We have studied the electrical properties of the ultra thin dendrimer LB films investigated by the current-voltage(I-V) characteristics of Metal/Dendrimer LB films/Metal(MIM) structure. And we have investigated different results in the surface activity at the air-water interface as well as the electrical properties for the monolayers of pure dendrimer with pyridinevopanol group and its complex with $Pt^4+$ ions. In conclusion, it is demonstrated that the metal ion around dendrimer with pyri야nepropanol group can contribute to make formation of network structure among dendrimers and it result from the change of electrical properties. This results suggest that the dendrimers with azobenzene group and pvridinedropanol group can be applied to high efficient nano-device of molecular level.

• Journal of Integrative Natural Science
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• v.5 no.4
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• pp.237-240
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• 2012

In this study, PEDOT thin films polymerized with Iron(III)tosylate ($Fe(PTS)_3$) and grown on atomically smooth and highly dense 3-aminopropyltriethoxysilane self-assembled monolayer (APS-SAM) surfaces by VPP method have been investigated. PEDOT thin films were synthesized on APS self-assembled $SiO_2$ wafer surface at two different concentrations (20 wt% and 40 wt%) and growth time (3 and 30 minutes), and then their sheet resistance were measured and compared. PEDOT thin films grown with 20 wt% $Fe(PTS)_3$ oxidant are highly conductive when compared with the film grown with 40 wt% $Fe(PTS)_3$, as ascertained by the measured sheet resistance values down to 0.06 ${\Omega}/cm$. It clearly suggests that 20 wt% is more effective oxidant concentration for VPP than 40 wt% even though the film grown with 40 wt% oxidant has better quality than the film with 20 wt% $Fe(PTS)_3$ does.

• Journal of the Korean Applied Science and Technology
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• v.26 no.4
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• pp.400-406
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• 2009

We investigated the electrochemical properties for Langmuir-Blodgett (LB) films of functionalized polyimide. LB films of polyimide monolayer were deposited by the Langmuir-Blodgett method on the indium tin oxide(ITO) glass. The electrochemical properties measured by cyclic voltammetry with a three-electrode system(an Ag/AgCl reference electrode, a platinum wire counter electrode and LB film-coated ITO working electrode) at various concentrations(0.5, 1.0, and 1.5 N) of $NaClO_4$ solution. The current of reduction and oxidation range was measured from 1650 mV to -1350 mV, continuously. The scan rates were 50, 100 and 150 mV/s, respectively. As a result, monolayer and multilayer LB films of polyimide are appeared on irreversible process caused by the oxidation current from the cyclic voltammogram.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.11a
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• pp.166-167
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• 2006

Dendrimers represent a new class of synthetic macromolecules characterized by a regularly branched treelike structure. Multiple branching yields a large number of chain ends that distinguish dendrimers from conventional star-like polymers and microgels. The azobenzene dendrimer is one of the dendrimeric macromolecules that include the azo-group exhibiting a photochromic character. Due to the presence of the charge transfer element of the azo-group and its rod-shaped structure, these compounds are expected to have potential interest in electronics and photoelectronics, especially in nonlinear optics. In the present paper, we give pressure stimulation to organic thin films and detect the induced displacement current. Functional photoisometrization organic molecular the photo-stimulus to organic monomolecular L-films and LB films of dendrimer and 8A5H were performed. The 8A5H organic monolayer in case of pressure stimulus occurred that positive course but in case of the photo-stimulus compared positive and negative. It is assumed that generation forms of displacement current were measured when photo-stimulus for Impression.

• Journal of the Microelectronics and Packaging Society
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• v.12 no.2 s.35
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• pp.181-186
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• 2005

We fabricated thin films of polystyrene-block-poly(methyl methacrylate)(PS -b-PMMA) on the self-assembled monolayers(SAM) of 3-(p-methoxyphenyl)propyltrichlorosilane(MPTS) on silicon wafers. Cylindrical nanodomains of PMMA or PS were oriented perpendicular to the surface of silicon wafers due to the neutral affinity of the SAM to PS and PMMA blocks. By selective removal of the PMMA block with UV irradiation and washing, nanoporous films and nanorod assemblies were produced. The nanoporous film can be used for a nanolithographical mask.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.55 no.12
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• pp.586-590
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• 2006

Dendrimers represent a new class of synthetic macromoleculcs characterized by a regularly branched treelike structure. Multiple branching yields a large number of chain ends that distinguish dendrimers from conventional star-like polymers and microgels. The azobenzene dendrimer is one of the dendrimeric macromolecules that include the azo-group exhibiting a photochromic character. Due to the presence of the charge transfer element of the azo-group and its rod-shaped structure, these compounds are expected to have potential interest in electronics and photoelectronics, especially in nonlinear optics. In the present paper, we give pressure stimulation to organic thin films and detect the induced displacement current. Functional photoisometrization organic molecular the photo-stimulus to organic monomolecular L films and LB films of dendrimer and 8A5H were performed. The 8A5H organic monolayer in case of pressure stimulus occurred that positive course but in case of the photo-stimulus compared positive and negative. It is assumed that generation forms of displacement current were measured when photo-stimulus for impression.