• Title/Summary/Keyword: self-assembled

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Synthesis of $SiO_2$ nanoparticles self-assembled thin film by organic.inorganic hybrid method

  • Hu, Yi;Lyu, Jhong-Ming;Liu, Tung-Cheng;Liu, Jiun-Shing
    • 한국정보디스플레이학회:학술대회논문집
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    • 2009.10a
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    • pp.1538-1541
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    • 2009
  • Amphiphobic thin films for touched panel application was prepared by $SiO_2$ nanoparticles self-assembled nanostructure. Silicon dioxide nano spheres were prepared by sol-gel method and well dispersed in a solution with surfacants of low surface energy. Nanostrcture thin films were obtained by spin coating technologies.

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Random Walk Simulation for the Growth of Monolayer in Dip Pen Nanolithography

  • Kim, Hyojeong;Ha, Soojung;Jang, Joonkyung
    • Bulletin of the Korean Chemical Society
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    • v.34 no.1
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    • pp.164-166
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    • 2013
  • Using a simple random walk model, this study simulated the growth of a self-assembled monolayer (SAM) pattern generated by dip-pen nanolithography (DPN). In this model, the SAM pattern grew mainly via the serial pushing of molecules deposited from the tip. This study examined various SAM patterns, such as lines, crosses and letters, by changing the tip scan speed.

Synthesis ad Self-assembled Multilayer Film Fabrication via Layer-by-layer Deposition of Water-soluble Aromatic Polyimines

  • Lee, Taek-Seung;Kim, Jae-Hyeon;Kumar, Jayant;Tripathy, Sukant
    • Proceedings of the Korean Fiber Society Conference
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    • 1997.10a
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    • pp.71-75
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    • 1997
  • A new series of water-soluble conjugated aromatic polyimines containing sulfonate groups have been synthesized via polycondensation reaction between diamines and dialdehydes at room temperature. Self-assembled multilayer films consisting each polyimine as a polyanion and poly(diallyldimethylammonium hydrochloride) as a polycation were fabricated successfully by alternate deposition in corresponding aqueous solutions.

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Surface modification for block copolymer nanolithographyon gold surface

  • Hwang, In-Chan;Bang, Seong-Hwan;Lee, Byeong-Ju;LeeHan, Bo-Ram;Kim, Hyeong-Jun
    • Proceedings of the Materials Research Society of Korea Conference
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    • 2009.11a
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    • pp.33.2-33.2
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    • 2009
  • Block copolymer lithography has attracted great attention for emerging nanolithography since nanoscaleperiodic patterns can be easily obtained through self-assembly process without conventional top-down patterning process. Since the morphologies of self-assembled block copolymer patterns are strongly dependent on surface energy of a substrate, suitable surface modification is required. Until now, the surface modification has been studied by using random copolymer or self-assembled mono layers (SAMs). However, the research on surface modifications has been limited within several substrates such as Si-based materials. In present study, we investigated the formation of block copolymer on Au substrate by $O_2$ plasma treatment with the SAM of 3-(p-methoxy-phenyl)propyltrichloro-silane [MPTS, $CH_3OPh(CH_2)_3SiCl_3$]. After $O_2$ plasma treatment, the chemical bonding states of the surface were analyzed by X-ray photoelectron spectroscopy (XPS). The static contact angle measurement was performed to study the effects of $O_2$ plasma treatment on the formation of MPTS monolayer. The block copolymer nanotemplates formed on Au surface were analyzed by scanning electron microscopy. The results showed that the ordering of self-assembled block copolymer pattern and the formation of cylindrical nano hole arrays were enhanced dramatically by oxygen plasma treatment. Thus, the oxidation of gold surface by $O_2$ plasma treatment enables the MPTS to form the monolayer assembly leading to surface neutralization of gold substrates.

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Self-Assembled Chiral Structures of Discoid Organic Molecule on Au(111)

  • Kim, Ji-Hoon;Khang, Se-Jong;Kwon, Young-Kyun;Park, Yongsup
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.02a
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    • pp.280-280
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    • 2013
  • Using both experimentaland theoretical methods, we have investigated the structural and electronic properties of self-assembled two-dimensional organic molecule (hexaaza-triphenylene-hexacarbonitrile, HATCN), which is used as an efficient OLED hole injection material, on Au(111) surfaces. Low-temperature scanning tunneling microscope (STM) measurements revealed that self-assembled linear and hexagonal porous structures are formed at atomic steps and terraces of Au(111), respectively. We also found that the hexagonal porous structure have chirality and forms only small (<1,000 nm2) phase-separated chiral domains that can easily change their chiral phase in subsequence STM images at 80 K. To explain these observations, we calculated the molecular-molecular and molecule-surface interaction energies by using first-principles density functional theory method. We found that the change of their chiral phase resulted from the competition between the two energies. These results have not only verified our experimental observations, but also revealed the delicate balance between different interactions that caused the self-assembed structures at the surface.

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Fabrication of Au(111) substrate and tunneling current characteristics of self-assembled Viologen molecule (Au(111) 기판 제작과 자기조립된 Viologen 분자의 tunneling current 특성)

  • Lee, Nam-Suk;Choi, Won-Suk;Qian, Dong-Jin;Kwon, Young-Soo
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2006.11a
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    • pp.255-256
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    • 2006
  • The electrical properties of viologen ($VC_8SH$) were studied in terms of the tunneling current characteristics using self-assembling techniques and ultra high vacuum scanning tunneling microscopy (UHV-STM). We fabricated the Au substrate were deposited by thermal evaporation system($420^{\circ}C$). Self-assembled monolayers (SAMs) were prepared on Au(111), which had been thermally deposited onto freshly cleaved, heated mica. The Au substrate was exposed to a 1 mM/L solution of Octanethiol in ethanol for 24 h to form a monolayer. After through rinsing the sample, it was exposed to a 0.1 mM/L solution of $VC_8SH$ in ethanol for 30 min. We measurement of the morphology on the single viologen molecule. The current-voltage (I-V) properties were measured at arbitary configured points on the surface of the sample by using a STS.

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Nano-scale Probe Fabrication Using Self-assembly Technique and Application to Detection of Escherichia coli O157:H7

  • Oh, Byung-Keun;Lee, Woochang;Lee, Won-Hong;Park, Jeong-Woo
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.8 no.4
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    • pp.227-232
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    • 2003
  • A self-assembled monolayer of protein G was fabricated to develop an immunosensor based on surface plasmon resonance (SPR), thereby improving the performance of the antibodybased biosensor through immobilizing the antibody molecules (lgG). As such, 11-mercaptoundecanoic acid (11-MUA) was adsorbed on a gold (Au) support, while the non-reactive hydrophilic surface was changed through substituting the carboxylic acid group (-COOH) in the 11-MUA molecule using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrocholide (EDAC). The formation of the self-assembled protein G layer on the Au substrate and binding of the antibody and antigen were investigated using SPR spectroscopy, while the surface topographies of the fabricated thin films were analyzed using atomic force microscopy (AFM). A fabricated monoclonal antibody (Mab) layer was applied for detecting E. coli O157:H7. As a result, a linear relationship was achieved between the pathogen concentration and the SPR angle shift, plus the detection limit was enhanced up to 10$^2$ CFU/mL.

Sonochemical Synthesis of Closed [5,6]-bridged Aziridino[70]fullerene Derivative and Self-assembled Multilayer Films

  • Yoon, Shin-Sook;Hwang, Sung-Ho;Hong, Sung-Kyu;Lee, Jeong-Ho;Ko, Weon-Bae
    • Carbon letters
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    • v.10 no.4
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    • pp.325-328
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    • 2009
  • This cycloaddition of [70]fullerene with methyl azidoacetate in benzene under ultrasonic irradiated condition afforded the closed [5,6]-bridged aziridino[70]fullerene derivative, which was unusual product of cycloaddition to the 5,6-junction of fullerene. Its structure was determined by FAB-MS, UV-vis, $^1H-$ and $^{13}C$-NMR spectral data. The closed [5,6]-bridged aziridino[70]fullerene-functionalized gold nanoparticle films were self-assembled using the layer-by-layer method on the reactive of glass slides functionalized with 3-mercaptopropyl trimethoxysilane. The functionalized glass slides were alternately soaked in the solution containing closed the [5,6]-bridged aziridino[70]fullerene and 4-aminothiophenoxide/hexanethiolate-protected gold nanoparticles. The closed [5,6]-bridged aziridino[70]fullerene-functionalized gold nanoparticle films have grown up to 5 layers depending on the immersion time. The self-assembled nanoparticle multilayer films were characterized using UV-vis spectroscopy showed that the surface plasmon band of gold at 527 nm gradually became more evident as successive layers were added to the films.

Facile preparation of self-assembled wool-based graphene hydrogels by electron beam irradiation

  • Park, Mira;Pant, Bishweshwar;Choi, Jawun;Park, Yong Wan;Lee, Chohye;Shin, Hye Kyoung;Park, Soo-Jin;Kim, Hak-Yong
    • Carbon letters
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    • v.15 no.2
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    • pp.136-141
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    • 2014
  • Three dimensional self-assembled graphene hydrogels were easily fabricated by electron beam irradiation (EBI) using an aqueous solution of wool/poly(vinyl alcohol) and graphene oxide (GO). After exposure to various levels of EBI radiation, the highly porous, self-assembled, wool-based graphene hydrogels were characterized using scanning electron microscopy and Fourier-transform infrared spectroscopy; to determine the gel fraction, degree of swelling, gel strength, kinetics-of-swelling analyses and removal of hexavalent chromium (Cr(VI)) from the aqueous solution. X-ray diffraction results confirmed that EBI played a significantly important role in reducing GO to graphene. The adsorption equilibrium of Cr(VI) was reached within 80 min and the adsorption capacity was dramatically increased as the acidity of the initial solution was decreased from pH 5 to 2. Changes in ionic strength did not exert much effect on the adsorption behavior.

Electrochemical Properties of Self-Assembled Viologen Monolayers Using Quartz Crystal Analyzer (QCA를 이용한 자기조립된 Viologen 단분자막의 전기화학적 특성)

  • Lee, Dong-Yun;Park, Sang-Hyun;Shin, Hoon-Kyu;Park, Jae-Chul;Chang, Jeong-Soo;Kwon, Young-Soo
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2004.04b
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    • pp.141-144
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    • 2004
  • Molecular self-assembled of surfactant viologens are recently interesting because they can be from functional electrodes as well as micelle assemblies which can be profitably utilized for display devices, electrochemical studies and electrocatalysis as electron acceptor or electron mediator. The electrochemical behavior of self-assembled viologen monolayer on Au electrode surface has been investigated with QCM which has been known as nano-gram order mass detector. A monolayer of viologen is immobilized on the gold electrode surface and the normal potentials corresponding to the to the successive one-electron transfer processes of the viologen actives are two peaks in 0.1mol/l phosphate buffer solution respectively. These result suggest that the viologen SAMs are stable and well-behaved monolayers.

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