• Title/Summary/Keyword: molecular orientation

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Electrical Properties of Nanoscale LB Layers of Amphiphilic Conducting Material (전도성 양친매성의 Nanoscale LB 막의 전기적 특성)

  • 최인희;박수길;김재호;조병호;이주성
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1996.11a
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    • pp.221-224
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    • 1996
  • We synthesized amphiphilic material including dye skeleton, p-phenylenediamine(PD) by attaching norma-decyl group of two strands at a part of coordinating atom, for obtaining reasonable design of LB uniform films. The synthesis of this compounds was quantitatively carried out under ultra pure state. This product was identified with FT-lR spectroscopy, UV absortion spectroscopy, and $^1$H-NMR spectroscopy, respectively. When manufacturing monolayer, we confirmed molecular area from pressure-area($\pi$-A) cutie of thiscompound onto the surface of the water. The spectroscopic approach also has done by UV absortion spectroscopy. It was shown that PD-complex LBfilms were deposited well with monolayer thickness. The conductivity based on I-V characteristics of PD-complex LB films were in the range of 10$^{-10}$ S/cm at room temperture. The microscopic properties by AFM, showed the good orientation of various monolayer or multilayer molecules

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A Study on Electro-optical Characteristics of a-TN-LCD with Polarization of Orientation Film (배향막의 극성에 따른 a-TN-LCD의 전기광학특성에 관한 연구)

  • 서대식;이창훈
    • Electrical & Electronic Materials
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    • v.10 no.10
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    • pp.1011-1015
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    • 1997
  • In this paper we investigated the electro-optical characteristics of amorphous (a)- twisted nematic (TN)-liquid crystal display(LCD) on polymide (PI) surfaces with different molecular structure. It was found that the domaine size of a-TN-LCD on PI with high polarization is small compared to a-TN-LCD on PI with medium polarization. It is considered that the response time of a-TN-LCd contributes to surface effect between the substrate surfaces and the LC molecules. Finally we obtained that the viewing angle of a-TN-LCD on PI surfaces increases with decreasing the domain size.

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Photoinduced Charge-Transfer Association of Tetracyanoquinodimethane with Aminobiphenyls

  • Kim, Yong-Hee;Jung, Sang-Don;Chung, Myung-Ae;Song, Ki-Dong;Cho, Dae-Won
    • Bulletin of the Korean Chemical Society
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    • v.29 no.5
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    • pp.948-952
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    • 2008
  • The molecular association of acceptors with electron donors is studied in the highly-polar solvent $CH_3CN$. Tetracyanoquinodimethane (TCNQ) forms a stable charge-transfer complex with donor molecules such as 4- aminobiphenyl (4-AB), benzidine (BD) and 2-aminobiphenyl (2-AB) with high association constants. The complexes of TCNQ with 4-AB or BD show new absorption bands at around 800 and 500 nm, which can be identified as reduced $TCNQ^{{\bullet}-}$ and $TCNQ^{2-}$ species, respectively. These bands grow quickly upon photoirradiation, implying that the charge-transfer complexes are easily formed in an excited state. Conversely, a small spectral manifestation of the charge transfer was observed in the case of 2-AB complex. It is demonstrated that the structural orientation between the geminate ion pairs could play an important role in building a stable complex.

The Crystal Structure of 1,3-Alternate 25,27-Bis(1-propyloxy)calix[4]arene crown-6, $C_{44}H_{54}O_8$ (1,3-Alternate 25,27-Bis(1-propyloxy)calix[4]arene crown-6, $C_{44}H_{54}O_8$의 결정구조)

  • 김종승;이원구;추건홍;이창희;이진호;김문집;김진구;서일환
    • Korean Journal of Crystallography
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    • v.10 no.2
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    • pp.130-135
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    • 1999
  • The title compound consisting of a calix[4]arene molecule with four phenyl rings bridged by four methylene groups and arranged alternately in anti-orientation fashion, two 25,27-bis(1-pro-pyloxy) groups attached on the two lower rims of calix[4]arene, and crown-6 chain attached on the other set of lower rims of calix[4]arene offers a big cavity inside a molecule which might possess a potential for forming host-guest complexes. The molecular packing is accomplished by van der Waals forces.

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Computational Tridimensional Protein Modeling of Cry1Ab19 Toxin from Bacillus thuringiensis BtX-2

  • Kashyap, S.;Singh, B.D.;Amla, D.V.
    • Journal of Microbiology and Biotechnology
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    • v.22 no.6
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    • pp.788-792
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    • 2012
  • We report the computational structural simulation of the Cry1Ab19 toxin molecule from B. thuringiensis BtX-2 based on the structure of Cry1Aa1 deduced by x-ray diffraction. Validation results showed that 93.5% of modeled residues are folded in a favorable orientation with a total energy Z-score of -8.32, and the constructed model has an RMSD of only $1.13{\AA}$. The major differences in the presented model are longer loop lengths and shortened sheet components. The overall result supports the hierarchical three-domain structural hypothesis of Cry toxins and will help in better understanding the structural variation within the Cry toxin family along with facilitating the design of domain-swapping experiments aimed at improving the toxicity of native toxins.

A Study on the Langmuir-Blodgett Films of Polyamic Acid Monolayer Containing p-Nitroazobenzene (p-Nitroazobenzene을 함유한 Polyamic Acid 단분자층의 Langmuir-Blodgett 막에 관한 연구)

  • Park, Keun-Ho
    • Journal of the Korean Applied Science and Technology
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    • v.28 no.2
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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.

Surface Tension of Liquid Water (물의 표면장력)

  • Hyungsuk Pak;Seihun Chang
    • Journal of the Korean Chemical Society
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    • v.8 no.3
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    • pp.121-124
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    • 1964
  • Considering the molecular orientation on the first surface layer and applying the significant structure theory of liquid water proposed by the authors in the previous paper, the surface tension of liquid water is calculated for various temperatures which agree well with the observed values.

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Ferromagnetic resonance of Hensler $Ni_2$MnGa thin films

  • M. D. Huang;Lee, N. N.;Lee, Y. P.;J. Y. Rhee;J. Dubowik
    • Journal of the Korean Vacuum Society
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    • v.12 no.S1
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    • pp.116-119
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    • 2003
  • $Ni_2$MnGa films, deposited on mica and glass substrates, were studied by ferromagnetic resonance (FMR) technology. The temperature-dependent resonance field was measured and a martensitic phase transformation (MT) was found between 310 and 340 K, exhibiting an abnormality on the curve. The easy axis is found to be in the film plane. The line width increases as a whole with decreasing temperature, which is discussed in terms of the motional narrowing mechanism. The resonance field was also measured as a function of orientation and the results were fitted, exhibiting a good consistence.

A study on the growth and the molecular orientation and the surface Characterization of $\alpha$-Sexithiophene thin films by OMBD technique (유기빔성막법을 이용한 $\alpha$-Sexithiophene 박막의 제조 및 분자 배향과 표면 특성에 관한 연구)

  • 권오관;오세운;박미경;김영관;신동명;최종선;손병청
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1997.11a
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    • pp.328-330
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    • 1997
  • Organic semiconductors such as conjugated polymers and oligomers have been studied many research groups. The band structures of conjugated polymers and oligomers are similar to those of conventional inorganic semiconductors Thin films based on these materials show a promising potential for Field Effect Transistors(FETs) and Light Emitting Diodes(LED) because fabrication processes are simple and cheaper for large electronic devices and flexible devices are also possible.

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