검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 31

        25.
        2016.05 구독 인증기관·개인회원 무료
        There have been continuous research activities towards the designing of various separation technologies for the sequestration of CO2. Organic polymer membranes pay a great attention for its eco-friendliness, simple operation and energy-saving. Polymer membranes such as polyimides, polyethers, TRs and PIMs are well known for their high permeability and excellent mechanical, chemical, and thermal properties. However, the foremost challenge for these polymeric membrane materials is their enhanced selectivity to CO2 without sacrificing permeability. The selectivity problems would be overcome by ionic liquids (ILs), which lead to a considerable attention on RTILs-based sequestrations for CO2/N2 and CO2/CH4 separations. The current research trends based on RTIL polymer membranes, together with our original concept of applying RTIL to various polymeric structures will be presented.
        26.
        2016.05 구독 인증기관·개인회원 무료
        Cu nanoparticles generated by redox reduction with Fe2+ ions and porous KIT-6 were utilized for high selectivity and permeance. When positively polarized Cu nanoparticles were generated and porous KIT-6 materials were incorporated into ionic liquid 1-butyl-3-methyl imidazolium tetrafluoroborate (BMIM BF4), these membranes showed the selectivity for CO2/N2 and CO2/CH4 was largely enhanced to 16.4 and 23.4, respectively while neat BMIMBF4 was 5.0 and 4.8, respectively. Furthermore, the CO2 permeance was also enhanced to 50.7 GPU. It was thought that these enhancements of separation performance was attributed to both the facilitated transport by polarized CuNPs and the increase of diffusivity by porous materials. Therefore, highly selective and permeable membrane for CO2 separation was successfully prepared.
        27.
        2016.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Nitrogen (N)-doped ordered mesoporous carbons (OMCs) with a dual transition metal system were synthesized as non-Pt catalysts for the ORR. The highly nitrogen doped OMCs were prepared by the precursor of ionic liquid (3-methyl-1-butylpyridine dicyanamide) for N/C species and a mesoporous silica template for the physical structure. Mostly, N-doped carbons are promoted by a single transition metal to improve catalytic activity for ORR in PEMFCs. In this study, our N-doped mesoporous carbons were promoted by the dual transition metals of iron and cobalt (Fe, Co), which were incorporated into the N-doped carbons lattice by subsequently heat treatments. All the prepared carbons were characterized by via transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). To evaluate the activities of synthesized doped carbons, linear sweep was recorded in an acidic solution to compare the ORR catalytic activities values for the use in the PEMFC system. The dual transition metal promotion improved the ORR activity compared with the single transition metal promotion, due to the increase in the quaternary nitrogen species from the structural change by the dual metals. The effect of different ratio of the dual metals into the N doped carbon were examined to evaluate the activities of the oxygen reduction reaction.
        4,300원
        28.
        2015.11 구독 인증기관·개인회원 무료
        A simple method for generating pores in a cellulose acetate (CA) polymer matrix was developed using a combination of an ionic liquid and water pressure treatment. A porous CA membrane was successfully prepared using the ionic liquid (BMIM-BF4) and subsequent water pressure treatment. Pores were generated in the CA polymer matrix when the CA/ionic liquid composite was subjected to water pressure. The characteristics of the thus-generated porous membrane were evaluated using porosimetry. FT-IR and Thermogravimetric analysis (TGA) showed that when the CA polymer was subjected to water pressure, most of the BMIM-BF4 incorporated in the polymer during its preparation was removed, thereby generating the observed pores. In addition, it was observed that the flux varied with water pressure, indicating that the pore size was controllable.
        29.
        2014.07 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study reports on the influenceof N-butyl-N-methylpyrrolidinium tetrafluoroborat (PYR14BF4) ionic liquid additive on the conducting and interfacial properties of organic solvent based electrolytes against a carbon electrode. We used the mixture of ethylene carbonate/dimethoxyethane (1:1) as an organic solvent electrolyte and tetraethylammo-nium tetrafluoroborate(TEABF4) as a common salt. Using the PYR14BF ionic liquid as additive produced higher ionic conductivity in the electrolyte and lower interface resis-tance between carbon and electrolyte, resulting in improved capacitance. The chemical and electrochemical stability of the electrolyte was measured by ionic conductivity me-ter and linear sweep voltammetry. The electrochemical analysis between electrolyte and carbon electrode was examined by cyclic voltammetry and electrochemical impedance spectroscopy.
        4,000원
        30.
        2012.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 이산화탄소를 효율적으로 분리하기 위한 이온성액체 지지분리막 제조를 목적으로 한다. 공칭크기 0.1 mum PVDF 정밀여과막에 이온성액체인 [bmim][PF6] (1-butyl-3-methylimidazolium hexafluorophosphate)를 분리막 세공내로 흡입시켜 고정화하였다. 제조된 이온성액체 지지막에 대한 N2, H2, CO2 기체의 투과도는 0.075, 0.203, 1.380 GPU로 측정되었으며 CO2/N2, H2/N2의 선택도는 각각 14.2와 2.69이었다. 또한 이온성액체 지지분리막은 이온성 액체가 운전압력 2.0 bar까지 세공 내에 고정되어 안정적으로 운전 가능하였다.
        3,000원
        31.
        2012.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Herein, macroporous carbon foams were successfully prepared with phenol and formaldehyde as carbon precursors and an ionic liquid, 1-butyl-3-methylimidazolium hexafluorophosphate (BMIPF6), as a pore generator by employing a polymerization-induced phase separation method. During the polycondensation reaction of phenol and formaldehyde, BMIPF6 forms a clustered structure which in turn yields macropores upon carbonization. The morphology, pore structure, electrical conductivity of carbon foams were investigated in terms of the amount of the ionic liquid. The as-prepared macroporous carbon foams had around 100-150 μm-sized pores. More importantly, the electrical conductivity of the carbon foams was linearly improved by the addition of BMIPF6. To the best of the author's knowledge, this is the first result reporting the possibility of the use of an ionic liquid to prepare porous carbon materials.
        4,000원
        1 2