• Title/Summary/Keyword: nano complex

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Nano Carbon Material Based Electrochemical Actuators (탄소 나노 재료 기반의 전기-화학적 구동기)

  • Cha, Ju-Young;Kang, In-Pil
    • Journal of the Korean Society for Precision Engineering
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    • v.28 no.11
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    • pp.1251-1258
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    • 2011
  • With the help of nanoscale materials like carbon nanotube (CNT), there is the potential to develop new actuators that will provide higher work per cycle than previous actuator technologies, and generate much higher mechanical strength. In this study, the electrochemical actuation characteristics of nano carbon materials were experimentally studied to develop electrochemical actuators. The electrochemical actuators were composed of aqueous NaCl electrolyte and their actuating electrodes were made of multi-walled carbon nanotube (MWCNT)/polystyrene composite and graphene respectably. Actuation is proportional to charging transfer rate, and the electrolysis with an AC voltage input has very complex characteristics. To quantify the actuation property, the strain responses and output model were studied based on electrochemical effects between the nano carbon films and the electrolyte.

Structural Heal th Monitoring Based On Carbon Nanotube Composite Sensors (나노 센서를 이용한 구조물 건전성 감시 기법)

  • Kang, In-Pil;Lee, Jong-Won;Choi, Yeon-Sun;Schu1z Mark J.
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2006.03a
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    • pp.613-619
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    • 2006
  • This paper introduces a new structural health monitoring using a nano sensor. The sensor is made of nano smart composite material based on carbon nanotubes. The nano sensor is fabricated as a thin and narrow polymer film sensor that is bonded or deposited onto a structure. The electrochemical impedance and dynamic strain response of the neuron change due to deterioration of the structure where the sensor is located. A network of the long nano sensorcan form a structural neural system to provide large area coverage and an assurance of the operational health of a structure without the need for actuators and complex wave propagation analyses that are used with other methods.

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Mechanical properties of top neck mollusks shell nano composite in different environmental conditions

  • Masir, Amin Nouroozi;Darvizeh, Abolfazl;Zajkani, Asghar
    • Advances in materials Research
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    • v.7 no.3
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    • pp.185-194
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    • 2018
  • The mechanism of biological materials structure is very complex and has optimal properties compared to engineering materials. Top Neck mollusks shells, as an example of biological materials, have hierarchical structure, which 95 percent of its structure is Aragonite and 5 percent organic materials. This article detected mechanical properties of the Top Neck mollusks shell as a Nano composite using Nano-indentation method in different situations. Research findings indicate that mechanical properties of the Top Neck mollusks shell including elastic modulus and hardness are higher than a fresh one preserved in -50 centigrade and also a Top Neck mollusks shell preserved in environmental conditions. Nano-indentation test results are so close in range, overall, that hardness degree is 3900 to 5200 MPa and elastic modulus is 70 to 85 GPa.

Tetrameric Self-Assembly of a Cu(II) Complex Containing Schiff-Base Ligand and Its Unusually High Catecholase-like Activity

  • Sarkar, Shuranjan;Lee, Woo Ram;Hong, Chang Seop;Lee, Hong-In
    • Bulletin of the Korean Chemical Society
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    • v.34 no.9
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    • pp.2731-2736
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    • 2013
  • We report a new tetrameric supramolecular Cu(II) complex ($Cu_4L_4$ = tetrakis(N,N'-bis(salicylidene)-2,2'-ethylenedianiline)Copper(II)) with a Schiff-base ligand ($H_2L$ = N,N'-bis (salicylaldimine)-1,2-ethylenediamine) containing two N,O-bidentate chelate groups. Though the copper sites of $Cu_4L_4$ are non-coupled, the complex exhibits a unsually high catecholase-like activity ($k_{cat}=935h^{-1}$) when the $Cu_4L_4$ solution is treated with 3,5-di-tert-butylcatechol (3,5-DTBC) at basic condition in the presence of air. Combined information obtained from UV-VIS and EPR measurements could lead the suggestion of the reaction pathway in which the substrate may bind to Cu(II) ions by anti-anti didentate bridging mode.

Synthesis, Characterization and Liquid Phase Oxidation of Cyclohexane with Hydrogen Peroxide over Oxovanadium(IV) Schiff-base Tetradendate Complex Covalently Anchored to Multi-Wall Carbon Nanotubes (MWNTs)

  • Salavati-Niasari, Masoud;Bazarganipour, Mehdi
    • Bulletin of the Korean Chemical Society
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    • v.30 no.2
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    • pp.355-362
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    • 2009
  • The chemical modification of multi-wall carbon nanotubes (MWNTs) is an emerging area in material science. In the present study, hydroxyl functionalized oxovanadium(IV) Schiff-base; N,N'-bis(4-hydroxysalicylidene)-ethylene-1, 2-diamineoxovanadium(IV), [VO($(OH)_2$-salen)]; has been covalently anchored on modified MWNTs. The new modified MWNTs ([VO($(OH)_2$-salen)]-MWNTs]) have been characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron (XPS), UV-Vis, Diffuse reflectance (DRS), FT-IR spectroscopy and elemental analysis. The analytical data indicated a composition corresponding to the mononuclear complex of tetradentate Schiff-base ligand. The characterization of the data showed the absence of extraneous complex, retention of MWNTs and covalently anchored on modified MWNTs. Liquid-phase oxidation of cyclohexane with $H_2O_2$ to a mixture of cyclohexanone, cyclohexanol and cyclohexane-1,2-diol in $CH_3$CN have been reported using oxovanadium(IV) Schiff-base complex covalently anchored on modified MWNTs as catalysts. This catalyst is more selective toward cyclohexanol formation.

A New Approach to Surface Imaging by Nano Secondary Ion Mass Spectrometry

  • Hong, Tae-Eun;Byeon, Mi-Rang;Jang, Yu-Jin;Kim, Jong-Pil;Jeong, Ui-Deok
    • Proceedings of the Korean Vacuum Society Conference
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    • 2016.02a
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    • pp.105.1-105.1
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    • 2016
  • Many of the complex materials developed today derive their unique properties from the presence of multiple phases or from local variations in elemental concentration. Simply performing analysis of the bulk materials is not sufficient to achieve a true understanding of their physical and chemical natures. Secondary ion mass spectrometer (SIMS) has met with a great deal of success in material characterization. The basis of SIMS is the use of a focused ion beam to erode sample atoms from the selected region. The atoms undergo a charge exchange with their local environment, resulting in their conversion to positive and negative secondary ions. The mass spectrometric analysis of these secondary ions is a robust method capable of identifying elemental distribution from hydrogen to uranium with detectability of the parts per million (ppm) or parts per billion (ppb) in atomic range. Nano secondary ion mass spectrometer (Nano SIMS, Cameca Nano-SIMS 50) equipped with the reactive ion such as a cesium gun and duoplasmatron gun has a spatial resolution of 50 nm which is much smaller than other SIMS. Therefore, Nano SIMS is a very valuable tool to map the spatial distribution of elements on the surface of various materials In this talk, the surface imaging applications of Nano SIMS in KBSI will be presented.

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Preparation of ZnO@TiO2 nano coreshell structure by the polymerized complex and sol-gel method (착체중합법과 sol-gel법에 의한 ZnO@TiO2 나노 코아쉘 구조의 제조)

  • Lim, Chang Sung
    • Analytical Science and Technology
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    • v.21 no.3
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    • pp.237-243
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    • 2008
  • Nano core shell structures of $TiO_2$ particles coated on surface of ZnO nanoparticles were prepared by the polymerized complex and sol-gel method. The average particle size of ZnO by the polymerized complex method showed 100 nm and the average particle size of $TiO_2$ by the sol-gel method showed below 10 nm. The average particle size of $ZnO@TiO_2$ nano core shell struture represented about 150 nm. The agglomeration between the ZnO particles using the polymerized complex method was highly controlled by the uniform absorption of $TiO_2$ colloid on the spherical ZnO surfaces. The driving force of heterogeneous bonding between ZnO and $TiO_2$ was induced by the Coulomb force. The ZnO and $TiO_2$ particles electrified with + and - charges, respectively, resulted in strong bonding by the difference of iso-electric point (IEP) when they laid neutrality pH area, depending on the heterogeneous surface electron electrified by the different zeta potential on the pH values.

Chitosan-Cu-salen/Carbon Nano-Composite Based Electrode for the Enzyme-less Electrochemical Sensing of Hydrogen Peroxide

  • Jirimali, Harishchandra Digambar;Saravanakumar, Duraisamy;Shin, Woonsup
    • Journal of Electrochemical Science and Technology
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    • v.9 no.3
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    • pp.169-175
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    • 2018
  • Cu-Salen complex was prepared and attached into chitosan (Cs) polymer backbone. Nanocomposite of the synthesized polymer was prepared with functionalized carbon nano-particles (Cs-Cu-sal/C) to modify the electrode surface. The surface morphology of (Cs-Cu-sal/C) nanocomposite film showed a homogeneous distribution of carbon nanoparticles within the polymeric matrix. The cyclic voltammogram of the modified electrode exhibited a redox behavior at -0.1 V vs. Ag/AgCl (3 M KCl) in 0.1 M PB (pH 7) and showed an excellent hydrogen peroxide reduction activity. The Cs-Cu-sal/C electrode displays a linear response from $5{\times}10^{-6}$ to $5{\times}10^{-4}M$, with a correlation coefficient of 0.993 and detection limit of $0.9{\mu}M$ (at S/N = 3). The sensitivity of the electrode was found to be $0.356{\mu}A\;{\mu}M^{-1}\;cm^{-2}$.

Synthesis of (Co,Mg)Al2O4 and (Ni,Mg)Al2O4 Blue Ceramic Nano Pigment by Polymerized Complex Method (착체중합법을 이용한 (Co,Mg)Al2O4 및 (Ni,Mg)Al2O4 청색 나노 무기안료 합성)

  • Son, Bo-Ram;Yoon, Dea-Ho;Kim, Jin-Ho;Han, Kyu-Sung;Cho, Woo-Suk;Hwang, Kwang-Taek
    • Journal of the Korean Ceramic Society
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    • v.50 no.6
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    • pp.510-517
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    • 2013
  • In this study, the properties of blue inorganic nano-pigments with a spinel structure were systematically investigated. We report the preparation of a blue ceramic nano-pigment and the Co and Ni substitutional effects on the blue color. $MgAl_2O_4$ was selected as the crystalline host network for the synthesis of cobalt and nickel-based blue ceramic nano-pigments. Various compositions of $Co_xMg_{1-x}Al_2O_4$ and $Ni_xMg_{1-x}Al_2O_4$ ($0{\leq}x{\leq}1$) powders were prepared using apolymerized complex method. The obtained powder was preheated at $400^{\circ}C$ for 5 h and then calcined at $1000^{\circ}C$ for 5 h. XRD patterns of the (Co,Mg)$Al_2O_4$ and (Ni,Mg)$Al_2O_4$ samples showed a single phase of the spinel structure in all compositions. TEM results indicated nano-sized pigments for (Co,Mg)$Al_2O_4$ and (Ni,Mg)$Al_2O_4$ with a particle size ranging from 20 to 50 nm. The characteristics of the color tones of (Co,Mg)$Al_2O_4$ and (Ni,Mg)$Al_2O_4$ were analyzed by CIE $L^*a^*b^*$ measurements. In addition, the thermal stability and the binding characteristics of (Co,Mg)$Al_2O_4$, (Ni,Mg)$Al_2O_4$ are discussed in terms of the TG-DSC and FT-IR results, respectively.