• Title/Summary/Keyword: 메조포러스

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Preparation of Mesoporous Molecular Sieve by the Reaction of Na2SiO3 and H2SiF6 in the Presence of an Aqueous Nonionic Surfactant Solution (비이온성 계면활성제 수용액에서 Na2SiO3와 H2SiF6의 반응을 통한 메조포러스 실리카의 제조)

  • Kim, Jin-Yeong;Kwon, Oh-Yun
    • Applied Chemistry for Engineering
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    • v.29 no.1
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    • pp.122-126
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    • 2018
  • Mesoporous molecular sieves were prepared by the reaction of $Na_2SiO_3$ and $H_2SiF_6$ using nonionic micelle templates in an aqueous solution. Well-crystalline mesoporous molecular sieves were obtained after several seconds at atmospheric conditions. Powder samples exhibited d-spacing of 3.8-5.1 nm with the sharpness of the d00l peak, showing well-crystalline mesoporous molecular sieves, pore size distributions of 2.5-3.1 nm and large specific surface areas of $290-1,018m^2/g$, depending on types of surfactants. SEM images of samples showed well-divided spherical particles with an uniform size of ${\sim}0.5{\mu}m$ and TEM images demonstrated uniform pores with a worm hole shape.

Adsorption of Gaseous Benzene onto Mesoporous Silicates (메조포러스 실리케이트에 의한 기상 벤젠 흡착)

  • Lee, Chae Young;Moon, Nam Gu;Chung, Jin Suk;Shin, Eun Woo
    • Applied Chemistry for Engineering
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    • v.19 no.4
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    • pp.452-456
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    • 2008
  • Mesoporous silicate materials have been used as adsorbents due to the advantage of high specific surface area and regular mesopores. In this study, conventional mesoporous silicates (MCM-41, and SBA-15) were utilized as adsorbents for gaseous benzene, one of volatile organic compounds. In the results of the breakthrough curves of gaseous benzene, SBA-15 showed a higher benzene adsorption capacity in adsorption condition of this study. Especially, compared to benzene adsorption of zeolite X, that of SBA-15 was higher by a factor of 2.7. With increasing adsorption temperature, adsorption capacity for benzene of SBA-15 was decreased rapidly. This indicates that benzene adsorbed weakly on SBA-15.

P(VDF-HPF)-Based Polymer Electrolyte Filled with Mesoporous ZnS (메조포러스 ZnS가 충전된 P(VDF-HPF) 고분자 전해질)

  • Seo, Young-ju;Cha, Jong-Ho;Lee, Huen;Ha, Yong-Joon;Koh, Jeong Hwan;Lee, Chulhaeng
    • Korean Chemical Engineering Research
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    • v.46 no.1
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    • pp.170-174
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    • 2008
  • ZnS-polymer gel films were prepared with incorporating mesoporous ZnS synthesized by surfactant-assisted templating process and poly (vinylidene fluoride)-hexafluoropropylene copolymer (P(VDF-HFP)) in order to observe the variation of ionic conductivities according to the various weight ratios between ZnS and P(VDF-HFP). Ionic conductivities for each gel electrolyte were measured with increasing temperature. As a result, ionic conductivities increased with increasing the amount of ZnS and temperature. In particular, the films with 20 and 25 wt% ZnS were found that they possessed the high ionic conductivity of approximately $10^{-4}Scm^{-1}$ at room temperature. However, above 20 wt% of ZnS, the enhancement of ionic conductivity was not observed. For the characterization of ZnS and the gel electrolyte, XRD (x-ray diffractometer), DSC (differential scanning calorimetry), TGA (thermogravimetric analysis), FT-IR (fourier transform-infrared spectrometer), SEM (scanning electron microscopy) and TEM (transmission electron microscopy) were employed. Ionic conductivities were measured by a.c. impedance method.

Synthesis of Mesoporous Pt-Au Alloy Electrode by Electrodeposition Method for Direct Methanol Fuel Cell (전기화학적 증착법에 의한 직접 메탄올 연료전지(DMFC)용 메조포러스 백금-금 합금전극제조)

  • Park, Eun-Kyung;Ahn, Jae-Hoon;Kim, Young-Soo;Kim, Kyung-Hwa;Baeck, Sung-Hyeon
    • Korean Chemical Engineering Research
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    • v.46 no.4
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    • pp.727-731
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    • 2008
  • Mesoporous Pt-Au alloy films were successfully fabricated on ITO-coated glass by electrodeposition method using tri-blockcopolymer (P123) as a templating agent. The electrolyte consisted of 10 mM hydrogen hexachloroplatinate ($H_2PtCl_6$), 10 mM hydrogen tetrachloroaurate ($HAuCl_4$), and proper amount of P123. For comparison, control samples were electrodeposited without $HAuCl_4$ and P123. Film composition was determined by EDS(Energy Dispersive X-ray Spectroscopy), and the mesoporous structure was confirmed by TEM(Transmission Electron Microscopy). SEM(Scanning Electron Microscopy) was utilized to examine surface morphology, and it was observed that the addition of P123 affected the particle growth, resulting in the significant change of surface morphology. Methanol oxidation and CO oxidation were carried out to investigate electrocatalytic activities of synthesized samples. It was observed that the catalytic activity was strongly dependent on the film compositions. Compared with nonporous electrode prepared without P123 templating, mesoporous films prepared with P123 templating showed much higher catalytic activities and stability for both methanol oxidation and CO oxidation. These enhanced electrocatalytic activities were due to the high surface area and facilitated charge transfer of mesoporous films.

Soft-template Synthesis of Magnetically Separable Mesoporous Carbon (자성에 의해 분리 가능한 메조포러스 카본의 소프트 주형 합성)

  • Park, Sung Soo;Ha, Chang-Sik
    • Journal of Adhesion and Interface
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    • v.18 no.2
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    • pp.75-81
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    • 2017
  • In this study, we synthesized mesoporous carbon (Carbonized Ni-FDU-15) containing nanoporous structures and magnetic nanoparticles. Carbonized Ni-FDU-15 was synthesized via evaporation-induced self-assembly (EISA) and direct carbonization by using a triblock copolymer (F127) as a structure-directing agent, a resol precursor as a carbon-pore wall forming material, and nickel (II) nitrate as a metal ion source. The mesoporous carbon has a well-ordered two-dimensional hexagonal structure. Meanwhile, nickel (Ni) metal and nickel oxide (NiO) were produced in the magnetic nanoparticles in the pore wall. The size of the nanoparticles was about 37 nm. The surface area, pore size and pore volume of Carbonized Ni-FDU-15 were $558m^2g^{-1}$, $22.5{\AA}$ and $0.5cm^3g^{-1}$, respectively. Carbonized Ni-FDU-15 was found to move in the direction of magnetic force when magnetic force was externally applied. The magnetic nanoparticle-bearing mesoporous carbons are expected to have high applicability in a wide variety of applications such as adsorption/separation, magnetic storage media, ferrofluid, magnetic resonance imaging (MRI) and drug targeting, etc.