• 제목/요약/키워드: Polymer science

검색결과 5,809건 처리시간 0.032초

Small-Angle X-ray Scattering Station 4C2 BL of Pohang Accelerator Laboratory for Advance in Korean Polymer Science

  • Yoon, Jin-Hwan;Kim, Kwang-Woo;Kim, Je-Han;Heo, Kyu-Young;Jin, Kyeong-Sik;Jin, Sang-Woo;Shin, Tae-Joo;Lee, Byeong-Du;Rho, Ye-Cheol;Ahn, Byung-Cheol;Ree, Moon-Hor
    • Macromolecular Research
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    • 제16권7호
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    • pp.575-585
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    • 2008
  • There are two beamlines (BLs), 4C1 and 4C2, at the Pohang Accelerator Laboratory that are dedicated to small angle X-ray scattering (SAXS). The 4C1 BL was constructed in early 2000 and is open to public users, including both domestic and foreign researchers. In 2003, construction of the second SAXS BL, 4C2, was complete and commissioning and user support were started. The 4C2 BL uses the same bending magnet as its light source as the 4C1 BL. The 4C1 BL uses a synthetic double multilayer monochromator, whereas the 4C2 BL uses a Si(111) double crystal monochromator for both small angle and wide angle X-ray scattering. In the 4C2 BL, the collimating mirror is positioned behind the monochromator in order to enhance the beam flux and energy resolution. A toroidal focusing mirror is positioned in front of the monochromator to increase the beam flux and eliminate higher harmonics. The 4C2 BL also contains a digital cooled charge coupled detector, which has a wide dynamic range and good sensitivity to weak scattering, thereby making it suitable for a range of SAXS and wide angle X-ray scattering experiments. The general performance of the 4C2 BL was initially tested using standard samples and further confirmed by the experience of users during three years of operation. In addition, several grazing incidence X-ray scattering measurements were carried out at the 4C2 BL.

Interfacial Layers for High Efficiency Polymer Solar Cells

  • Kim, Youn-Su;Choi, Ha-Na;Son, Seon-Kyoung;Kim, Ta-Hee;Kim, Bong-Soo;Kim, Kyung-Kon
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2011년도 제41회 하계 정기 학술대회 초록집
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    • pp.74-74
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    • 2011
  • Polymer solar cells utilize bulk heterojunction (BHJ) type photo-active layer in which the electron donating polymer and electron accepting C60 derivatives are mixed together. In the BHJ system the electron donating polymer and electron accepting C60 derivatives are blended. The blended system causes charge recombination at the interface between the BHJ active layer and electrode. To reduce the charge recombination at the interface, it is needed to use an interlayer that can selectively transfer electrons or holes. We have developed solution processable wide band gap inorganic interfacial layers for polymer solar cells. The effect of interlayers on the performance of polymer solar cell was investigated for various types of conjugated polymers. We have found that inorganic interfacial layers enhanced the solar cell efficiency through the reduction of charge recombination at the interface between active layer and electrode. Furthermore, the stability of the polymer solar cell using the interlayer was significantly improved. The efficiency of 6.5% was obtained from the PTB7:PCBM70 based solar cells utilizing $TiO_2$nanoparticles as an interlayers.

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Substitutional boron doping of carbon materials

  • Ha, Sumin;Choi, Go Bong;Hong, Seungki;Kim, Doo Won;Kim, Yoong Ahm
    • Carbon letters
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    • 제27권
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    • pp.1-11
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    • 2018
  • A simple, but effective means of tailoring the physical and chemical properties of carbon materials should be secured. In this sense, chemical doping by incorporating boron or nitrogen into carbon materials has been examined as a powerful tool which provides distinctive advantages over exohedral doping. In this paper, we review recent results pertaining methods by which to introduce boron atoms into the $sp^2$ carbon lattice by means of high-temperature thermal diffusion, the properties induced by boron doping, and promising applications of this type of doping. We envisage that intrinsic boron doping will accelerate both scientific and industrial developments in the area of carbon science and technology in the future.

Synthesis of Platinum Nanoparticles Using Electrostatic Stabilization and Cluster Duplication of Perfluorinated Ionomer

  • Lee, Pyoung-Chan;Kim, Dong-Ouk;Han, Tai-Hoon;Kang, Soo-Jung;Pu, Lyong-Sun;Nam, Jae-Do;Kim, Byung-Woo;Lee, Jun-Ho
    • Macromolecular Research
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    • 제17권3호
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    • pp.187-191
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    • 2009
  • Platinum (Pt) nanoparticles were prepared by the liquid-phase reduction of tetraammineplatinum (II) chloride $([Pt(NH_3)_4]Cl_2)$ using Nafion as a stabilizer under various conditions of the Nation phase. This method is novel in its use of electrostatic interactions between the Pt complex ions and sulfonic groups in the hydrated Nation molecules. The synthesized Pt nanoparticles of the recast film system had a cubic shape. In the case of the Nation solution system, the Pt nanoparticles mainly had a spherical shape. The shapes and sizes of the Pt nanoparticles were strongly influenced by the Nation phase.