• 제목/요약/키워드: chemical preparation method

검색결과 934건 처리시간 0.024초

Surface Modification Studies by Atomic Force Microscopy for Ar-Plasma Treated Polyethylene

  • Seo, Eun-Deock
    • Macromolecular Research
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    • 제10권5호
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    • pp.291-295
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    • 2002
  • Atomic force microscopy(AFM) was used to study the polyethylene(PE) surfaces grafted and immobilized with acrylic acid by Ar plasma treatment. The topographical images and parameters including RMS roughness and Rp-v value provided an appropriate means to characterize the surfaces. The plasma grafting and immobilization method were a useful tool for the preparation of surfaces with carboxyl group. However, the plasma immobilization method turned out to have a limitation to use as a means of preparation of PE surface with specific functionalities, due to ablation effect during the Ar plasma treatment process.

온도조절 화학기상증착법을 활용한 대용량 허니컴 구조촉매 제조 연구 (Study on the Simple Preparation Method of Honeycomb-structured Catalysts by Temperature-regulated Chemical Vapor Deposition)

  • 서민혜;김숭연;김영독;엄성현
    • 공업화학
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    • 제29권1호
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    • pp.18-21
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    • 2018
  • 본 연구에서는 대용량 구조 촉매의 제조 및 활용 가능성을 확인하고자 셀 밀도가 높은 세라믹 허니컴 구조체와 온도조절 화학기상증착법을 활용하여 촉매를 제조하고 건식 개질 반응에 대한 촉매 활성을 평가하였다. 셀 밀도 600 cpsi 코디어라이트 허니컴(CDR)을 대상으로 니켈을 코팅한 NiO/CDR 촉매는 코팅 조건과 시간을 조절함으로써 허니컴 구조체 셀 내부까지 충분한 균일 증착이 가능하였다, $800^{\circ}C$, 공간속도 $10,000h^{-1}$$CH_4$$CO_2$를 1 : 1로 주입한 조건에서 $CH_4$는 약 83%, $CO_2$는 약 90% 이상의 우수한 전환율을 보여 건식 개질 반응에 효과적으로 적용이 가능하다는 것을 확인하였다. 이 결과를 토대로 대면적, 대용량 촉매 제조 시 온도조절 화학기상증착법이 매우 유용하게 활용될 수 있음을 확인하였다.

Preparation and Characterization of Reduced Graphene Nanosheets via Pre-exfoliation of Graphite Flakes

  • Meng, Long-Yue;Park, Soo-Jin
    • Bulletin of the Korean Chemical Society
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    • 제33권1호
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    • pp.209-214
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    • 2012
  • In this work, the reduced graphene nanosheets were synthesized from pre-exfoliated graphite flakes. The pristine graphite flakes were firstly pre-exfoliated to graphite nanoplatelets in the presence of acetic acid. The obtained graphite nanoplatelets were treated by Hummer's method to produce graphite oxide sheets and were finally exfoliated to graphene nanosheets by ultrasonication and reduction processes. The prepared graphene nanosheets were studied by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), atomic force microscopy (AFM), and transmission electron microscopy (TEM). From the results, it was found that the preexfoliation process showed significant influence on preparation of graphite oxide sheets and graphene nanosheets. The prepared graphene nanosheets were applied to the preparation of conductive materials, which yielded a greatly improved electrical resistance of $200{\Omega}/sq$.

Preparation and characterization of prospective disulfide based electrode materials for lithium batteries

  • Ragupathy, Dhanusuraman;Gopalan, Anantha Iyengar;Lee, Kwang-Pill
    • 분석과학
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    • 제21권1호
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    • pp.25-33
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    • 2008
  • Organic disulfide compounds are having higher theoretical capacity than the conventional cathode material and are considered as the important storage material. Here, we are reporting the preparation of poly (2,2'-dithiodianiline) PDDA/multiwall carbon nanotubes, (MWCNTs) composites under different experimental conditions. Amine functionalized and unfunctionalized MWCNTs were independently used for the preparation of composites. Composites were prepared in the presence of cetyl trimethyl bromide (CTAB), a cationic surfactant, and also in the absence of CTAB. A physical mixture of PDTDA and MWCNTs was formed with unfunctionalized MWCNTs. Grafting of PDDA onto MWCNTs was performed by chemical oxidative polymerization of 2, 2'-dithiodianiline in the presence of amine functionalized MWCNTs. The composites of MWCNTs and PDTDA were characterized for structure, morphology and thermal properties through Fourier transform infrared spectroscopy, Fourier transform Raman spectroscopy, scanning electron microscopy and UV-visible spectroscopy. The composite materials prepared by this method are expected to find applications as electrode materials for lithium batteries.

An Efficient Synthesis of Substituted Quinolines via Indium(III) Chloride Catalyzed Reaction of Imines with Alkynes

  • Zhu, Mei;Fu, Weijun;Xun, Chen;Zou, Guanglong
    • Bulletin of the Korean Chemical Society
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    • 제33권1호
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    • pp.43-47
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    • 2012
  • An efficient synthetic method for the preparation of quinolines through indium(III) chloride-catalyzed tandem addition-cyclization-oxidation reactions of imines with alkynes was developed. The processes can provide a diverse range of quinoline derivatives in good yields from simple imines and alkynes.