• 제목/요약/키워드: electrostatic self-assembly

검색결과 22건 처리시간 0.024초

Self-assembly Coloration Approach on Cotton Fibers using Porphyrin

  • Kim, Byung-Soon;Li, Xiachuan;Kim, Sung-Hoon;Bae, Jin-Seo;Son, Young-A
    • 한국염색가공학회지
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    • 제20권5호
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    • pp.23-27
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    • 2008
  • In this work, poly(diallyldimethylammoniumchloride) (PDDAC) and meso-tetrakis(4-carboxyphenyl)porphyrin were considered to produce the self-assembly fabrication films. This method is based on the layer-by-layer (LbL) deposition produced by the electrostatic attraction between positively charged PDDAC and negatively charged porphyrin ions. The result of multilayer fabrication was discussed with the level of color strength (K/S). K/S spectra of the fabricated multilayer films showed gradual increase behaviors. In addition, the color photo images of the fabricated multilayer films showed that PDDAC and porphyrin were successfully attracted by electrostatic self-assembly forces.

자기조립법을 이용한 고에너지물질의 표면개질 연구 (Surface Modification of High Energetic Materials by Molecular Self-assembly)

  • 김자영;정원복;신채호;김진석;이근득;이기봉
    • 한국추진공학회지
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    • 제20권2호
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    • pp.18-23
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    • 2016
  • 유기 분자의 자기조립 다분자막은 기질의 표면에서 전자기적인 상호작용을 통해 자발적으로 형성된다. 본 연구에서는 이 기술을 응용하여 고에너지물질의 안전성과 취급용이성이 향상됨을 입증하였다. 최근 다양한 연구에서 고에너지물질 결정 내부의 결함은 물질의 안전성을 저하시키는 요인이므로, 결정 입자의 크기를 감소시키는 연구가 중요시되고 있다. 이에 따라, 결정화 방법을 통해 제조된 나노 수준의 고에너지물질을 사용하였으며, 자기조립 다분자막 기술을 응용하여 물질의 안전성을 향상시켰다. 입도/표면전하/마찰감도/정전기 전하 등을 측정하여 표면개질 여부를 확인하였다.

Electrochemical Characterization of Multilayered CdTe/PSS Films Prepared by Electrostatic Self-assembly Method

  • Rabbani, Mohammad Mahbub;Yeum, Jeong Hyun;Kim, Jungsoo;Nam, Dae-Geun;Oh, Weontae
    • Transactions on Electrical and Electronic Materials
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    • 제15권5호
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    • pp.257-261
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    • 2014
  • Multilayered CdTe/PSS films were prepared by the electrostatic self-assembly method in an aqueous medium. Positively-charged cadmium telluride (CdTe) nanoparticles and anionic polyelectrolyte, poly (sodium 4-styrene sulfonate) (PSS) were assembled alternately in order to build up a multilayered film structure. A linear proportion of absorbance to the number of bilayers suggests that an equal amount of CdTe was adsorbed after each dipping cycle, which resulted in the buildup of a homogenous film. The binding energies of elements (Cd and Te) in multilayered CdTe/PSS film shifted from those of the CdTe nanoparticles in the pure state. This result indicates that the interfacial electron densities were redistributed by the strong electrostatic interaction between the oppositely-charged CdTe and PSS. Electrochemical properties of the multilayered CdTe/PSS films were studied in detail by cyclic voltammetry (CV).

Spin-coated ultrathin multilayers and their micropatterning using microfluidic channels

  • Hongseok Jang;Kim, Sangcheol;Jinhan Cho;Kookheon Char
    • Korea-Australia Rheology Journal
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    • 제15권1호
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    • pp.1-7
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    • 2003
  • A new method is introduced to build up organic/organic multilayer films composed of cationic poly(allylamine hydrochloride) (PAH) and negatively charged poly (sodium 4-styrenesulfonate) (PSS) using the spinning process. The adsorption process is governed by both the viscous force induced by fast solvent elimination and the electrostatic interaction between oppositely charged species. On the other hand, the centrifugal and air shear forces applied by the spinning process significantly enhances desorption of weakly bound polyelectrolyte chains and also induce the planarization of the adsorbed polyelectrolyte layer. The film thickness per bilayer adsorbed by the conventional dipping process and the spinning process was found to be about 4 ${\AA}$ and 24 ${\AA}$, respectively. The surface of the multilayer films prepared with the spinning process is quite homogeneous and smooth. Also, a new approach to create multilayer ultrathin films with well-defined micropatterns in a short process time is Introduced. To achieve such micropatterns with high line resolution in organic multilayer films, microfluidic channels were combined with the convective self-assembly process employing both hydrogen bonding and electrostatic intermolecular interactions. The channels were initially filled with polymer solution by capillary pressure and the residual solution was then removed by the .spinning process.

Packing Density Parameters of Palladium Nanoparticle Monolayers Fabricated via Spin-Coating Electrostatic Self-Assembly

  • An, Minshi;Hong, Jong-Dal;Cho, Kyung-Sang;Lee, Eun-Sung;Choi, Jae-Young
    • Bulletin of the Korean Chemical Society
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    • 제29권3호
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    • pp.623-626
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    • 2008
  • Spin-coating electrostatic self-assembly (SCESA) is utilized to fabricate a single layer of carboxylic-acid-coated Pd nanoparticles (NPs) (D??5 nm) on an oppositely charged surface. The packing density of a NP monolayer formed on a rotating solid substrate (3000 rpm) was examined with regards to various parameters, including the particle concentration, the pH, and the ionic strength of the solution. Initially, the packing density grew exponentially with increases in the particle concentration, up to a maximum value (of 8.4 ´ 1011/cm2) at 1.2 wt%. The packing density was also found to increase drastically as the pH decreased and the ionic strength of the solution increased; these trends can be attributed to a reduction in the interparticle repulsions among the NPs in the solution and on the substrate. The best result of this study was achieved in a 1.2 wt% solution at pH 8; under these conditions, an NP monolayer with the highest density (namely, 1.6 ´ 1012/cm2) was obtained.

베르베린 천연색소화합물과 음이온고분자전해질을 이용한 layer-by-layer self-assembly 색소다층박막 제조 (Layer-by-layer self-assembly colorant multi-layer preparation using natural colorant Berberine and anionic polyelectrolyte)

  • 손영아;박영민;이승구
    • 한국염색가공학회지
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    • 제18권1호
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    • pp.28-32
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    • 2006
  • A multi-layer of the dye, natural colorant Berberine, was successfully developed by the self-assembly deposition from water-soluble cationic dye(Berberine chloride) and anionic polyelectrolyte PSS(Polysodium 4-styrenesulfonate) in aqueous solution via electrostatic attraction. The corresponding results on multi-layer were characterized by UV-Vis absorbance measurements. The growth of multi-layer formed by the sequential interaction was also determined. The findings measured by UV-Vis spectrophotometer showed that the bilayer deposition characteristic was linear and highly reproducible from layer to layer.

Direct Coloration using Self-assembly Fabrication Method on PET Fibers - Surface diazo coupling reaction -

  • Kim, Byung-Soon;Son, Young-A
    • 한국염색가공학회지
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    • 제19권5호
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    • pp.37-40
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    • 2007
  • The electrostatic layer-by-layer technique provides a convenient way to control the construction of ultrathin films at nano-scale ranges and can be easily obtained. It can be also applicable to fiber substrate with dye compounds. We have fabricated multilayer dye films using diazonium resin and three couplers, which are prepared by self-assembly approach. This method is based on layer-by-layer deposition using electrostatic attraction between oppositely charged ions. Beside, the diazo coupling reaction proceeded to form azo dye layer on the PET fibers the same time. The corresponding results of the multilayer films have been discussed on the level of color strength (K/S).