• 제목/요약/키워드: functionalized surface

검색결과 247건 처리시간 0.025초

Formation of Quantum Dot Fluorescent Monolayer Film using Peptide Bond

  • Inami, Watau;Nanbu, Koichi;Miyakawa, Atsuo;Kawata, Yoshimasa
    • 정보저장시스템학회논문집
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    • 제8권1호
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    • pp.1-5
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    • 2012
  • We present a method for preparing a quantum dot fluorescent monolayer film on a glass substrate. Since nanoparticles aggregate easily, it is difficult to prepare a nanoparticle monolayer film. We have used a covalent bond, the peptide bond, to fix quantum dots on the glass substrate. The surface of the quantum dot was functionalized with carboxyl groups, and the glass substrate was also functionalized with amino groups using a silane coupling agent. The carboxyl group can be strongly coupled to the amino group. We were able to successfully prepare a monolayer film of CdSe quantum dots on the glass substrate.

Effect of Nitrile-Functionalized Zwitterions on Electrochemical Properties of Electrolytes for Use in Lithium-ion Batteries

  • Lee, Bum-Jin;Kwak, Seung-Yeop
    • 한국재료학회:학술대회논문집
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    • 한국재료학회 2012년도 춘계학술발표대회
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    • pp.97.2-97.2
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    • 2012
  • This study examined the utility of two zwitterions, nitrile-functionalized zwitterions and a zwitterion without a nitrile group (MF-ZI), were used as additives along with 1 M $LiPF_6$ in ethylene carbonate (EC):diethylene carbonate (DEC) (3:7 V/V) (E-0) to form an electrolyte solution for use in lithium ion batteries comprising graphite and $LiCoO_2$ electrodes. The presence of NF-ZI (E-NF-ZI) in the electrolyte produced an ion conductivity comparable to that of E-0 and higher than that of an electrolyte containing MF-ZI (E-MF-ZI). Linear sweep voltammetry data revealed that the intensity of the E-NF-ZI reduction peak was lower than that of E-0. Furthermore, the successful formation of an SEI layer in the E-NF-ZI over graphite was confirmed by cyclic voltammetry data. These results were attributed to the adsorption of NF-ZI on the electrode surface, as verified by differential capacity measurements.

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NTAㆍNi2+-Functionalized Quantum Dots for VAMP2 Labeling in Live Cells

  • Yu, Mi-Kyung;Lee, Su-Ho;Chang, Sung-Hoe;Jon, Sang-Yong
    • Bulletin of the Korean Chemical Society
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    • 제31권6호
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    • pp.1474-1478
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    • 2010
  • An efficient method for labeling individual proteins in live cells is required for investigations into biological mechanisms and cellular processes. Here we describe the preparation of small quantum dots (QDs) that target membrane surface proteins bearing a hexahistidine-tag ($His_6$-tag) via specific binding to an nitrilotriacetic acid complex of nickel(II) ($NTA{\cdot}Ni^{2+}$) on the QD surfaces. We showed that the $NTA{\cdot}Ni^{2+}$-QDs bound to His-tag functionalized beads as a cellular mimic with high specificity and that QDs successfully targeted $His_6$-tagged vesicle-associated membrane proteins (VMAP) on cell surfaces. This strategy provides an efficient approach to monitoring synaptic protein dynamics in spatially restricted and confined biological environments.

Simultaneous reduction and functionalization of graphene oxide by polyallylamine for nanocomposite formation

  • Kim, Young-Kwan;Min, Dal-Hee
    • Carbon letters
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    • 제13권1호
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    • pp.29-33
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    • 2012
  • A novel strategy for the simultaneous reduction and functionalization of graphene oxide (G-O) was developed using polyallylamine hydrochloride (PAAH) as a multi-functional agent. The G-O functionalization by PAAH was carried out under basic conditions to catalyze the epoxide ring opening reaction of G-O with abundant amine groups of PAAH. We found that G-O was not only functionalized with PAAH but also reduced under the reaction condition. Moreover, the synthesized PAAH-functionalized G-O sheets were soluble in water and applicable to the synthesis of nanocomposites with gold nanoparticles.

Structural Analysis of Carboxylic Acid-Functionalized Multi-walled Carbon Nanotubes

  • 오원태;김정수;이건웅
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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    • pp.63-63
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    • 2007
  • Carboxylated multi-walled carbon nanotubes (MWNTs) were in detail characterized by XRD, XPS, FTIR, and thermogravimetric measurements. Carboxylic acid groups were functionalized to MWNTs using aqueous acid solutions. The change. of sonication and reflux conditions rarely influenced the degree of carboxylation on MWNTs, but reduced the thermal stability of the resulting carboxylated MWNTs. The characteristic Bragg peaks of pristine and carboxylated MWNTs were analyzed by XRD measurements. After acid treatment the diffraction peaks (100), (101), and (102) of pristine MWNTs disappeared, but the diffraction peak (002) was preserved in the carboxylated MWNTs. The introduction of carboxylic acid groups on MWNTs caused to improve the dispersibility of the resulting carboxylated MWNTs in water.

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Preparation and Characterization of Flexible Optical Composite Films Based on Bragg-Structured Interferometer

  • Um, Sungyong;Sohn, Honglae
    • 통합자연과학논문집
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    • 제6권4호
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    • pp.244-250
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    • 2013
  • Three types of functionalized flexible optical composite films based on Bragg structure porous silicon interferometer have been successfully fabricated by casting a toluene solution of polystyrene onto the free-standing porous silicon. The optical properties of composite films are measured. Surface functionalization of porous silicon is determined by FT-IR measurement. Reflectance and transparence properties of composite films are measured for the possible application of tunable optical filter and indicate that the transmission peak occurred at the identical location where the reflection peak appeared.

다중벽 탄소나노튜브의 표면처리에 따른 전기이중층 커패시터의 특성 (Surface Treatment of Multi-walled Carbon Nanotubes for Increasing Electric Double-layer Capacitance)

  • 김지일;김익준;박수진
    • 대한화학회지
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    • 제54권1호
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    • pp.93-98
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    • 2010
  • 본 연구에서는 Urea와 산 처리로 질소 및 산소 관능기가 도입된 다중벽 탄소나노튜브를 각각 제조하였으며, 표면처리에 따른 전기이중층 커패시터 (EDLCs) 특성을 관찰하였다. XPS, zeta-potential, 및 BET 분석방법을 이용하여 구조특성을 확인하였으며, 전기화학적 특성은 1 M 황산용액의 전해질에서 각각 50 $mVs^{-1}$과 100 $mVs^{-1}$의 주사속도로 순환전류 전압곡선 특성 실험을 통해 고찰하였다. 실험 결과로부터 MWNTs의 질소 원소구성비가 늘어날수록 축전용량이 증가하는 것을 확인하였으며, Urea 처리된 MWNTs의 축전용량이 가장 높은 수치를 나타내었다. 이는 전극 표면과 전하 활성종 간의 젖음성이 증가하고, 표면 관능기의 밀도가 증가하기 때문인 것으로 사료된다.

Characterization and Surface-Derivatization of Porous Silicon

  • Lee, Bo-Yeon;Hwang, Min-Woo;Cho, Hyun;Kim, Hee-Chol;Jang, Seunghyun
    • 통합자연과학논문집
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    • 제4권3호
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    • pp.182-186
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    • 2011
  • Chemical modification of porous silicon surface has been investigated to have different physical surface properties. Porous silicon modified with dodecyl functionality exhibits hydrophobic feature, however the oxidation of porous silicon to modify with hydroxyl group displays hydrophilic properties. Surface characterization for both dodecyl and hydroxyl derivatized porous silicon was investigated by FT-IR spectroscopy. To determine the surface coverage, the amine functionalized surface was reduced by dithiothreitol (DTT) and the released 2-thiopyridone was quantified by UV/vis spectroscopy.

Surface Functionalization of a Fluoropolymer by Ion Beam-induced Graft Polymerization of 4-Vinyl Pyridine

  • Jung, Chan-Hee;Hwang, In-Tae;Choi, Jae-Hak;Nho, Young-Chang
    • 방사선산업학회지
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    • 제4권4호
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    • pp.341-345
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    • 2010
  • The surface functionalization of a fluoropolymer by ion beam-induced graft polymerization was described in this research. The surface of poly(tetrafluoroethylene) (PTFE) films were irradiated by a 150 keV $H^+$ ions, and 4-vinyl pyridine (4VP) as a functional monomer was then thermally graft polymerized on the irradiated surface. The surface properties of poly(4-vinyl pyridine) (P4VP)-grafted PTFE films were investigated in terms of grafting degree, wettability, chemical structure, and morphology. The results revealed that the surface of PTFE films was successfully functionalized by ion beam-induced graft polymerization of 4VP.

Characteristics of Ultrathin Film Prepared through Nano-Sized Langmuir Blodgett Monolayer of Functionalized Polyimide

  • Park, Keun-Ho;Lee, Soo
    • 한국응용과학기술학회지
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    • 제26권2호
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    • pp.224-231
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    • 2009
  • Techniques measuring Maxwell displacement current (MDC) and LB films surface measuring technique have been applied to the study of monolayers of polyamic acid containing azobenzene. MDCs was generated from monolayers on the water surface by monolayer compression and expansion. It was generated when the area per molecule was about $103{\AA}^2\;and\;78{\AA}^2$ just before the initial rise of the surface pressure during the 1st and 2nd mixed monolayer compressions cycle, respectively. It was the maximum of MDCs appeared at the molecular area just before the initial rise of surface pressure in compression cycles, and we have found that the increase of aggregations causes the noticeable increase of the surface roughness.