• Title/Summary/Keyword: chemistry-fiber

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Oxyfluorination of Pitch-based Activated Carbon Fibers for High Power Electric Double Layer Capacitor (고출력 전기이중층 캐패시터를 위한 핏치계 활성탄소섬유의 함산소불소화 처리)

  • Jung, Min-Jung;Ko, Yoonyoung;Kim, Kyung Hoon;Lee, Young-Seak
    • Applied Chemistry for Engineering
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    • v.28 no.6
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    • pp.638-644
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    • 2017
  • Pitch based activated carbon fibers for electric double layer capacitor (EDLC) electrodes were treated by oxyfluorination via varying the ratio of fluorine and oxygen gases to improve high power property. As the partial pressure of fluorine increased, the oxyfluorinated activated carbon fibers showed an increase of linear fluorine functional groups. While the oxygen functional groups increased, no changes was observed with respect to the partial gas pressure. The specific surface area and pore volume decreased due to the etching reaction on the activated carbon fiber surface through oxyfluorination, but the mesopore volume increased about 4.5 times. In the case of activated carbon fibers treated with 50% of the fluorine gas partial pressure, the specific capacitance increased to about 29% and 61% at scan rates of 5 and 50 mV/s, respectively. The improvement of the specific capacitance was believed to be due to the introduction of oxygen and fluorine functional groups on the activated carbon fiber surface and the increase of mesopores through oxyfluorination.

Synthesis of Reactive Dye for Polypropylene Fiber (폴리프로필렌 纖維用 反應性染料의 合成)

  • Yong-Jin Lim;Hak-ki Lee
    • Journal of the Korean Chemical Society
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    • v.23 no.6
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    • pp.412-416
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    • 1979
  • Although isotactic polypropylene gives an excellent fiber having high tenacity, abrasion resistance and chemical stability, it has not been widely used as a fabric for chlothing because of its poor dyeability. A number of methods for improvement of its dyeability have been proposed, but they were too complicated and/or gave damage its original excellent properties of polypropylene. We now wish to report the synthesis of a new reactive dye for polypropylene fiber by means of carbenic process. A reactive dye was synthesized from azo disperse dye having an aldehyde group and tosylhydrazine. By using this synthesized reactive dye, polypropylene fiber was dyed to thick and fast color.

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System Development of Removing Dust and Odor from Manufacturing Process of FRP Products (FRP제품 가공시 발생하는 분진 및 악취 제거 시스템 개발)

  • Yun, Huy Kwan;Kim, Jae Yong
    • Applied Chemistry for Engineering
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    • v.20 no.5
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    • pp.547-552
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    • 2009
  • When fiber reinforced plastics (FRP) products are manufactured, dust and odor materials are inevitably generated in a workplace. To improve the bad condition of the workshop, we developed the Hybrid Bag Filter attached activated carbon fiber (ACF) and installed the system at two companies producing FRP goods. In order to raise the efficiency of dust collection, we set the ducts both on the ceiling and at the bottom of the wall and according to the circumstances of the workshop's space, moving dust collector also adopted as a different type of flexible duct. Pulse Jet Type Bag Filter is also equipped to operate the system more effectively, for the improved fine environment because of high dust removal efficiency. Finally, we investigated the removal tendency of the dust and odor when operating the System of Hybrid Bag Filter.

Effect of Solvents on the Structure of Electrospun PVP Fiber (PVP의 전기방사 섬유 제조에서 용매에 따른 구조 변화)

  • Park, Ju-Young;Lee, In-Hwa
    • Applied Chemistry for Engineering
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    • v.19 no.5
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    • pp.484-490
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    • 2008
  • Electrospun of PVP (polyvinylpyrrolidone) ultra fine fibers were fabricated using various solvents including methanol, ethanol, 2-propanol, butanol, acetone, methylene chloride, and DMF, which possess different properties such as boiling point, dielectric constant, and dipole moment. Electrospun PVP fiber was influenced by viscosity, conductivity, and surface tension of spinning solution. Therefore, the electrospun PVP fiber was successfully prepared under critical conditions of viscosity > $0.114kg/m{\cdot}s$, conductivity > 1.02 mS/m, surface tension < 30.0 mN/m. In case of an ethanol solvent system, average diameter of PVP fiber increased from 1701 nm to 5454 nm as increased the applied voltage from 10 kV to 20 kV.

Effect of the Chemical Treatment and Fiber Length of Kenaf on Physical Properties of HDPE/Kenaf/Expandable Microcapsule (HDPE/케나프/열팽창성 마이크로 캡슐의 물성에 미치는 섬유 길이 및 화학처리 영향)

  • Ku, Sun Gyo;Lee, Jong Won;Kim, Youn Cheol
    • Applied Chemistry for Engineering
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    • v.27 no.3
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    • pp.270-275
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    • 2016
  • High density polyethylene (HDPE)/kenaf fiber (KF) composites included two types of KF with different lengths were fabricated by using a twin screw extruder. A thermally expandable microcapsule (EMC) was used to form HDPE/KF. The KF lengths were 0.3 mm and 3 mm. The contents of KF and EMC were fixed at 20 wt% and 5 wt%, respectively. From FT-IR data of KF, which underwent chemical treatment, peaks around 1700 and $1300cm^{-1}$ decreased. This might be caused by the reduction of lignin and hemicellulose due to the chemical treatment of KF. Based on the specific gravity, thermal stability and tensile property, physical properties of the composites with a 3 mm fiber were good. However, if the fiber is longer, poor appearance might be caused due to the thermal degradation during processing. Thus, the adequate length of KF should be chosen to maintain the appearance and physical properties for industrial applications of HDPE/KF/EMC composites. The tensile strength for 0.3 mm fiber treated with chemicals increased slightly.

Formation Mechanism of Pores in Ni-P Coated Carbon Fiber Prepared by Electroless Plating Upon Annealing (무전해 니켈-인 도금법을 이용하여 도금된 탄소 섬유의 열처리 과정에서 나타나는 다공성 구조 생성 메커니즘 분석)

  • Ham, Seung Woo;Sim, Jong Ki;Kim, Young Dok
    • Applied Chemistry for Engineering
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    • v.24 no.4
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    • pp.438-442
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    • 2013
  • In the present work, electroless plating was used for coating thin films consisting mainly of Ni and P on carbon fiber. Structural changes appeared upon the post-annealing at various temperatures of the Ni-P film on carbon fiber was studied using various analysis methods. Scanning, a flat surface structure of Ni-P film on carbon fiber was found after electroless plating of Ni-P film on carbon fiber without post-annealing, whereas annealing at $350^{\circ}C$ resulted the formation of porous structures. With increasing the annealing temperature to $650^{\circ}C$ with an interval of $50^{\circ}C$, the pore size increased, but the density decreased. X-ray diffraction (XRD) showed the existence of metallic Ni, and Ni-P compounds before post-annealing, whereas the post-annealing resulted in the appearance of NiO peaks, and the decrease in the intensity of the peak of metallic Ni. Using X-ray photoelectron spectroscopy (XPS), phosphorous oxides were detected on the surface upon annealing at $650^{\circ}C$, and $700^{\circ}C$, which can be attributed to the phosphorous compounds originally existing in the deeper layers of the Ni films, which undergo sublimation and escape from the film upon annealing. Escape of phosphorous species from the bulk of Ni-P film upon annealing could leave a porous structure in the Ni films. Porous materials can be of potential applications in diverse fields due to their interesting physical properties such as high surface area, and methods for fabricating porous Ni films introduced here could be easily applied to a large-scale production, and therefore applicable in diverse fields such as environmental filters.