• Title/Summary/Keyword: functionalized surface

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Preparation of Self-Assembled of $\alpha$-D-Mannosyl Fullerene[$C_{60}$]-Gold Nanoparticle Films (자기조립법에 의한 $\alpha$-D-만노실 풀러렌[$C_{60}$]-금 나노입자 필름 제조)

  • Yoon, Shin-Sook;Hwang, Sung-Ho;Ko, Weon-Bae
    • Elastomers and Composites
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    • v.43 no.4
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    • pp.264-270
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    • 2008
  • $\alpha$-D-mannosyl fullerene[$C_{60}$]-functionalized gold nanoparticle films were selfassembled using the layer-by-layer method on the reactive of glass slides functionlized with 3-aminopropyltrimethoxysilane. The functionalized glass slides were alternately soaked in the solutions containing $\alpha$-D-mannosyl fullerene[$C_{60}$] and 4-aminothiophenoxide/hexanethiolate-protected gold nanoparticles. $\alpha$-D-mannosyl fullerene[$C_{60}$]-functionalized gold nanoparticle films have grown up to 5 layers depending on the immersion time. The self-assembled nanoparticle films were characterized using UV-vis spectroscopy showed that the surface plasmon band of gold at 530 nm gradually became more evident as successive layers were added to the films.

Adsorption Characteristics of Functionalized Activated Carbon for High Temperature CO2 Capture (고온 이산화탄소 포집을 위한 기능성 활성탄의 흡착특성)

  • Choi, Sung-Woo;Lee, Cheol-Gyu
    • Journal of Korean Society of Environmental Engineers
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    • v.37 no.3
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    • pp.175-181
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    • 2015
  • Activated carbon impregnated with polyethyleneimine (PEI) was evaluated as a functionalized adsorbent for $CO_2$ capture. The $CO_2$ adsorption characteristics of the adsorbents was undertaken using GC/TCD, BET surface area and FT-IR. A series of adsorbents were synthesized by impregnating 10, 30, 50 wt% of PEI on activated carbons and were investigated $CO_2$ adsorption capacity at high and low adsorption temperature. The $CO_2$ adsorption capacity at $20^{\circ}C$ and $100^{\circ}C$ was as follow: AC > PEI(10)-AC > PEI(30)-AC > PEI(50)-AC at $20^{\circ}C$ and PEI(10)-AC > PEI(30)-AC > PEI(50)-AC > AC at $100^{\circ}C$. Adsorption capacities of amine functionalized AC was lager than virgin AC at high temperature due to chemisorption by amino-group content. From the results, the PEI(10)-AC showed one of the most promising adsorbents for $CO_2$ capture from flue gas at high temperature.

Influence of Alkylation on Interface and Thermal Conductivity of Multi-walled Carbon Nanotubes-reinforced Epoxy Resin (알킬화가 다중벽탄소나노튜브로 강인화된 에폭시수지의 계면 및 열전도도에 미치는 영향)

  • Heo, Gun-Young;Rhee, Kyong-Yop;Park, Soo-Jin
    • Polymer(Korea)
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    • v.35 no.6
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    • pp.548-552
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    • 2011
  • Two functionalization methods, i.e., acid treatment and chemical amidation were performed to prepare the functionalized multi-walled carbon nanotubes (MWCNT), and the properties of epoxy/functionalized MWCNT composites were investigated and compared. Fourier transform infrared spectroscopy (FTIR) was used to confirm the surface functionality of the MWCNT obtained by the functionalization methods. The effects of the MWCNT functionalization on the interface and thermal conductivity were studied by zeta potential analyzer, scanning electron microscope and thermal conductivity analyzer. From these results, it was confirmed that the thermal conductivity of the epoxy/MWCNT composites could be increased by grafting with dodecylamine. This could be interpreted by relatively strong dispersion forces of the grafting MWCNT with dodecylamine in DGEBF epoxy resin. These results were in good agreement with the results that the zeta potential value of the grafting MWCNT with dodecylamine has a higher negative value than that of MWCNT with acid treatment.

Ultrasonic, Chemical Stability and Preparation of Self-Assembled Fullerene$[C_{70}]$-Gold Nanoparticle Films (자기조립 풀러렌$[C_{70}]$-금 나노입자 필름 제조와 초음파적, 화학적 안정성)

  • Ko, Weon-Bae;Shon, Young-Seok
    • Elastomers and Composites
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    • v.40 no.4
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    • pp.272-276
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    • 2005
  • [ $C_{70}$ ]-gold nanoparticle multilayer films were self-assembled using a 'dirt-ball' method on the reactive surface of glass slides functionalized with 3-aminopropyltrimethoxysilane. The functionalized glass slides were soaked in the solution containing both unmodified $C_{70}$ and ${\omega}$-amino-functionalized gold nanoparticles. Organic reaction (amination) facilitated the assembly of multilayer $C_{70}$-gold nanoparticle films, which have grown up to several layers. Chemical stability of $C_{70}$-gold nanoparticle films was studied by monitoring the changes in absorbance after the immersion of the films in acidic solution. In addition, ultrasonic stability of these nanoparticle films was studied by exposing them to ultrasonic irradiated surrounding, which resulted in partial desorption and a little aggregation of nanoparticles on solid surfaces.

Synthesis of Oligoquinoline Dendronized Fullerenes for Potential Use in Organic Photovoltaic Devices

  • Kwon, Tae-Woo;Jenekhe, Samson A.
    • Bulletin of the Korean Chemical Society
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    • v.33 no.8
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    • pp.2703-2706
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    • 2012
  • New C60 fullerenes derivatives [G1]-C60 (1) and [G2]-C60 (2) comprising of phenylenevinylene bridges and phenylquinoline peripheral surface groups were synthesized by 1,3-dipolar cycloaddition reaction of fullerene C60 with azomethine ylide in situ generated from [Gx]-CHO dendrons (x = 1 and 2) and sarcosine.

Characterization of partially functionalized diamond for detecting single mismatched DNA (부분적 기능화된 다이아몬드를 이용한 single mismatched DNA 검출 특성)

  • Yang, Jung-Hoon;Song, Kwang-Soup
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.12 no.4
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    • pp.29-33
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    • 2013
  • Here we report a partially aminated micropattern via direct functionalization and examine eleven different solution-phase probe DNAs hybridizing with the same target DNA on both hydrogen and oxygen terminated diamond. The hybridization intensities determined by epifluorescence microscopy were compared and are influenced strongly by the negatively charged surface and mismatched position of its sequence with immobilized probe DNA.

Hierarchically Structured, Functionalized Graphenes for a Highly Reversible Capacitive Charge Storage

  • Yu, Xu;Park, Ho Seok
    • Proceedings of the Korean Vacuum Society Conference
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    • 2014.02a
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    • pp.491.1-491.1
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    • 2014
  • Heteroatom phosphorous-doped graphene aerogel (PGA) with high surface area is successfully synthesized via hydrothermal method for high power and energy supercapacitors, including the advantage of three dimensional internetwork and constitutive graphene skeletons. The morphology of PGA was investigated by the scanning electron microscope, transmission electron microscope. The chemical structure and circumstances were confirmed by Raman and X-ray photoelectron spectroscopy, the phosphorus is successfully incorporated with the graphene sheets. As evidenced by electrochemical measurements, cyclic voltammetry and galvanostatic charge discharge, the hierarchically PGA has an unprecedented high capacitance, which contributes to the excellent high-rate performance of this material for supercapacitor application.

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Determination of nickel and cadmium in fish, canned tuna, black tea, and human urine samples after extraction by a novel quinoline thioacetamide functionalized magnetite/graphene oxide nanocomposite

  • Naghibzadeh, Leila;Manoochehri, Mahboobeh
    • Carbon letters
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    • v.26
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    • pp.43-50
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    • 2018
  • In this research, a novel and efficient quinoline thioacetamide functionalized magnetic graphene oxide composite ($GO@Fe_3O_4@QTA$) was synthesized and utilized for dispersive magnetic solid phase preconcentration of Cd(II) and Ni(II) ions in urine and various food samples. A number of diverse methods were employed for characterization of the new nanosorbent. The design of experiments approach and response surface methodology were applied to monitor and find the parameters that affect the extraction performance. After sorption and elution steps, the concentrations of target analytes were measured by employing FAAS. The highest extraction performance was achieved under the following experimental conditions: pH, 5.8; sorption time, 6.0 min; $GO@Fe_3O_4@QTA$ amount, 17 mg; 2.4 mL $1.1mol\;L^{-l}$ $HNO_3$ solution as the eluent and elution time, 13.0 min. The detection limit is 0.02 and $0.2ng\;mL^{-1}$ for Cd(II), and Ni(II) ions, respectively. The accuracy of the new method was investigated by analyzing two certified reference materials (sea food mix, Seronorm LOT NO 2525 urine powder). The interfering study revealed that there are no interferences from commonly occurring ions on the extractability of target ions. Finally, the new method was satisfactorily employed for rapid extraction and determination of target ions in urine and various food samples.

Enhanced Carbon Dioxide Adsorption on Post-Synthetically Modified Metal-Organic Frameworks

  • Ko, Na-Keun;Kim, Ja-Heon
    • Bulletin of the Korean Chemical Society
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    • v.32 no.8
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    • pp.2705-2710
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    • 2011
  • Four MOFs functionalized with 1-Me, 1-Pr, 1-Ph, and 1-$PhCF_3$ were prepared through post-synthetic modifications of a metal-organic framework (MOF), UMCM-1-$NH_2$ (1) with acetic, butyric, benzoic, and 4-(trifluoromethyl)benzoic anhydrides, respectively. Methane adsorption measurements between 253 and 298 K at pressures up to 1 bar indicated that both 1-Ph and 1-$PhCF_3$ adsorbed more $CH_4$ than the parent MOF, 1. All the functionalized MOFs adsorbed more $CO_2$ than 1 under conditions similar to the $CH_4$ test. The introduction of functional groups promoted adsorption of both $CH_4$ and $CO_2$ despite significantly reducing Brunauer-Emmet-Teller (BET) surface area: 4170 (1), 3550 (1-Me), 2900 (1-Pr), 3680 (1-Ph), and 3520 $m^2/g$ (1-$PhCF_3$). Electron-withdrawing aromatic groups (1-Ph, 1-$PhCF_3$) more effectively enhanced $CO_2$ adsorption than electron-donating alkyl groups (1-Me, 1-Pr). In particular, 1-Ph adsorbed 23% more $CO_2$ at 298 K and 50% more at 253 K than 1.

Lyophobized Ordered Mesoporous Silica Additives for Li-O2 Battery Cathode

  • Roev, Victor;Ma, Sang Bok;Lee, Dong Joon;Im, Dongmin
    • Journal of Electrochemical Science and Technology
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    • v.5 no.2
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    • pp.58-64
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    • 2014
  • The surface of an ordered mesoporous silica (OMS) was functionalized using 1H,1H,2H,2H-perfluorooctyltrimethoxysilane at $20^{\circ}C$ and $60^{\circ}C$. It was shown that only elevated temperature allows lyophobic properties on the walls of OMS, eventually preventing pore flooding with nonaqueous electrolytes. The functionalized OMSs (OMS-F) were characterized with various techniques: wettability test, $N_2$ sorption measurement, high-resolution transmission electron microscopy (HR-TEM). Cathodes of $10mg/cm^2$ loading were prepared with a commercial Pt/C catalyst and polyvinylidene fluoride (PVDF, 2.5 wt.%) binder using a typical doctor blade method on a commercial gas diffusion layer (GDL) in the presence or in the absence of OMS-F additives. Subsequent discharge-charge curves were taken in a 1M LiTFSI-TEGDME electrolyte at 60oC in pure oxygen atmosphere. It was found that the discharge capacity was significantly affected by OMS-F: 5 wt.% of additive extended discharge capacity by a factor 1.5. On the other hand, a similar OMS material but synthesized at $20^{\circ}C$ did not show lyophobic properties and deteriorated cathode capacity.