• Title/Summary/Keyword: nano materials

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Synthesis of Gold Nanoparticles by Chemical Reduction Method for Direct Ink Writing

  • Cho, Young-Sang;Son, Soo-Jung;Kim, Young-Kuk;Chung, Kook-Chae;Choi, Chul-Jin
    • Journal of Powder Materials
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    • v.17 no.5
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    • pp.390-398
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    • 2010
  • Aqueous gold nanoparticle dispersion was synthesized by chemical reduction method using diethanolamine as reducing agent and polyethyleneimine as dispersion stabilizer. The synthesis conditions for the stable dispersion of the gold nanoparticle suspension were determined by changing the amount of the reducing agent and dispersant during the wet chemical synthesis procedures. The face centered cubic lattice structure of the gold nanoparticles was confirmed by using X-ray diffraction and the morphologies of the nanoparticles were observed by transmission electron microscope. The synthesized gold nanoparticle dispersion was concentrated by evaporating the dispersion medium at room temperature followed by the addition of ethyleneglycol as humectant for the increase of the elastic properties to obtain gold nanoparticle inks for direct ink writing process. The line patterns were obtained with the gold nanoparticle inks during the writing procedures and the morphologies of the fine patterns were observed by scanning electron microscope.

Characteristics of Indium Tin Oxide Films Grown on PET Substrate Grown by Using Roll-to-Roll (R2R) Sputtering System (롤투롤 스퍼터 시스템을 이용하여 PET 기판위에 성막 시킨 ITO 박막의 특성 연구)

  • Cho, Sung-Woo;Choi, Kwang-Hyuk;Bae, Jung-Hyeok;Moon, Jong-Min;Jeong, Jin-A;Jeong, Soon-Wook;Park, No-Jin;Kim, Han-Ki
    • Korean Journal of Materials Research
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    • v.18 no.1
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    • pp.32-37
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    • 2008
  • The electrical, optical, structural and surface properties of an indium tin oxide (ITO) film grown on a flexible PET substrate using a specially designed roll-to-roll (R2R) sputtering system as a function of the DC power, $Ar/O_2$ flow ratio, and rolling speed is reported. It was observed that both the electrical and optical properties of the ITO film on the PET substrate were critically dependent on the $Ar/O_2$ flow ratio. In addition, x-ray diffraction examination results showed that the structure of the ITO film on the PET substrate was an amorphous structure regardless of the DC power and the $Ar/O_2$ flow ratio due to a low substrate temperature, which was maintained constant by a main cooling drum. Under optimized conditions, ITO film with resistivity of $6.44{\times}10^{-4}{\Omega}-cm$ and transparency of 86% were obtained, even when prepared at room temperature. Furthermore, bending test results exhibited that R2R-grown ITO film had good flexibility which would be applicable to flexible displays and solar cells.

Current Research Trends in Water Treatment Membranes Based on Nano Materials and Nano Technologies (나노 기술을 이용한 수처리 분리막 소재의 최근 연구동향)

  • Lee, Hee Dae;Cho, Young Hoon;Park, Ho Bum
    • Membrane Journal
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    • v.23 no.2
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    • pp.101-111
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    • 2013
  • Nano materials having large surface area, uniform dimensions or pores can be utilized in various membrane applications. Recently, many studies have been focused on the application of nano materials and nano technologies in membrane applications by the help of the discovery and development of nano technologies. in terms of mass transport channels or functional modification. However, there have been several technological limitations for commercialization. Nano materials and nano technologies can improve 1) permeability, selectivity, 2) mechanical, chemical, thermal stability or fouling tolerance of conventional membranes and even 3) introduce new functionalities such as specific affinity and reactivity.

Preparation of Nano Wire by Anodic Oxidation II. Production of Nano Wire Using Anodic Alumina Template (양극산화법에 의한 나노와이어 제조 II. 알루미나 템플레이트를 이용한 나노와이어 제조)

  • Jo, Su-Haeng;O, Han-Jun;Park, Chi-Seon;Jang, Jae-Myeong;Jo, Nam-Don;Ji, Chung-Su
    • Korean Journal of Materials Research
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    • v.12 no.1
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    • pp.89-93
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    • 2002
  • To investigate the effect of properties of pores in anodic alumina template(AAT) on the formation and characteristics of metal nano wires, Cu and Ni nano wires were manufactured using anodic alumina template formed in various electrolytes. The characteristics of prepared metal nano wires using AAT could be replicated from those of pores in AAT. The diameters of nano wires could be controlled by the widening process of anodic porous film in $H_3PO_4$ solution. The shape ratio of the nano wire was shown to be $170{\pm}30$ for Ni nano wire formed by AAT made in sulfuric acid.

Electrical and Mechanical Properties of Cu/Carbon Nano-Particle Hybrids Composites by Cathodic Electrophoresis (음극 전기영동법에 의해 제조된 구리/탄소 나노입자 하이브리드 복합재료의 전기적/기계적 특성 평가)

  • Lee, Wonoh;Lee, Sang-Bok;Choi, Oyoung;Yi, Jin-Woo;Byun, Joon-Hyung
    • Korean Journal of Metals and Materials
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    • v.48 no.12
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    • pp.1130-1135
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    • 2010
  • Cu/carbon nano-particle hybrids were fabricated through the cathodic electrophoretic deposition (EPD) process. CNT and CNF nano-particles were modified to give positive charges by polyethyleneimine (PEI) treatment before depositing them on the substrate. Since a Cu plate was used as an anode in the EPD process, Cu particles were also deposited along with the carbon nano-particles. Experimental observation showed the nano-hybrids constructed a novel formicary-like nano-structure which is strong and highly conductive. Utilizing the hybrids, carbon fiber composites were manufactured, and their electrical conductivity and interlaminar shear strength were measured. In addition, the deposition morphology and failure surface were examined by SEM observations. Results demonstrated that the electrical conductivities in the through-the-thickness direction and the interlaminar shear strength significantly increased by 350~2100% and 14%, respectively.