共查询到20条相似文献,搜索用时 156 毫秒
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评述了液晶态分子在分析化学中的应用进展,包括其超分子的分子识别作用,液晶在色谱,光谱探针,核磁共振谱等分析化学领域中的应用。 相似文献
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强碱离子交换树脂催化剂在有机合成中的应用 总被引:1,自引:0,他引:1
本文综述了近年来强碱阴离子交换树脂及其支载的高分子催化剂在相转移反应,缩合,加成反应,氧化还原,酯交换,水解等反应中的应用应用。 相似文献
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Polarz S Orlov AV Schüth F Lu AH 《Chemistry (Weinheim an der Bergstrasse, Germany)》2007,13(2):592-597
Transition-metal-oxide materials possessing ordered mesoporosity have recently attracted significant research interest due to their numerous potential applications. Among them, ordered mesoporous zinc oxide (ZnO) is a very tempting material because of the importance of ZnO in heterogeneous catalysis. Here, first results of the preparation of ordered mesoporous ZnO materials by using different templates are reported. Porous materials with high surface area, different pore sizes, and nanocrystalline ZnO walls were obtained. Furthermore, we compare the two fundamental templating techniques, involving liquid crystals or ordered mesoporous carbon materials as templates. Regarding the formation of mesoporous ZnO, it was evident that the hard-matter carbon template is superior. 相似文献
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由沸石纳米粒子自组装制备具有高催化活性中心和水热稳定的新型介孔分子筛材料 总被引:18,自引:0,他引:18
人们合成了一系列介孔分子筛材料,并发现它们在催化、吸附与分离以及化学组装制备先进材料和分子器件等方面具有很大的潜在应用价值.但是,介孔分子筛材料相对于微孔沸石分子筛存在着两个致命弱点:较低的水热稳定性和较不活泼的催化活性中心.这两个弱点大大地影响了介孔分子筛在催化反应中的广泛应用.本文系统地综述了最近几年利用沸石纳米粒子自组装制备具有高催化活性中心和水热稳定的介孔分子筛材料的研究进展.这包括利用硅铝沸石纳米粒子自组装制备具有强酸性和水热稳定的新型介孔硅铝分子筛材料,利用钛硅沸石纳米粒子自组装制备具有高催化氧化活性中心和水热稳定的新型钛硅介孔分子筛材料,以及利用含有不同杂原子的沸石纳米粒子自组装制备一系列水热稳定的新型介孔分子筛催化材料. 相似文献
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有序介孔材料是指孔径在2~50 nm之间的多孔材料, 是一类具有均匀孔径、 高有序度纳米孔道和高比表面积的新材料. 在过去30年里, 有序介孔材料的研究取得了长足的进步, 在可控合成、 结构设计和调控及功能化等方面形成了系统的理论. 同时, 其应用领域也不断被拓展, 包括能源存储与转化、 催化、 生物医药和传感等方面. 本文首先回顾了有序介孔材料的发展历史, 简要介绍发展过程中“里程碑式”的研究工作; 然后根据构效关系总结了其在不同领域应用的最新进展; 最后讨论了有序介孔材料领域进一步发展所面临的挑战与机遇, 并对未来前景进行了展望. 相似文献
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采用两步法将不同尺寸的silicalite-1分子筛纳米晶种通过自组装合成了一系列有序介孔silicalite-1分子筛。首先将强碱性的silicalite-1前驱体分别加热不同时间得到纳米晶种,然后在类似合成SBA-15的强酸性条件下组装成有序的介孔材料。合成条件的剧烈变化阻止了分子筛晶种的继续长大,并在三嵌段共聚物模板的诱导下组装成有序介孔材料。这种“自下而上”的方法制备有序介孔分子筛同时包含微孔和介孔。氮气吸脱附结果表明所制备的介孔分子筛材料均表现了很大的比表面积(730 m2/g以上)。 相似文献
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Kim Hyun-Jin Yang Eun-Hyeok Noh Young Su Hong Gi Hoon Park Ji In Shin Seol A Lee Kwan-Young Moon Dong Ju 《Research on Chemical Intermediates》2018,44(2):1131-1148
Research on Chemical Intermediates - Ordered mesoporous materials have received much attention because of their high surface area and ordered pore structure. The Mg-promoted ordered mesoporous... 相似文献
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Highly ordered mesoporous SiC materials were prepared by infiltrating viscous liquid preceramic polymer, allylhydridopolycarbosilane, into two types of surface modified nanoporous silica templates: mesoporous silica SBA-15 and mesocellular siliceous foam. The silica templates were subsequently etched off after pyrolysis at 1000 degrees C under nitrogen atmosphere with the resultant formation of ordered mesoporous structures. The mesoporous SiC materials, synthesized from both types of templates possessed high Brunauer-Emmett-Teller (BET) surface areas in the range of 250-260 m(2)/g with pore sizes of 3.4-3.6 nm. The ordered structures of mesoporous SiC were exact inverse replicas of their respective silica templates, as characterized by small angle X-ray diffraction (XRD), transmission electron microscope (TEM) images, and the adsorption-desorption isotherm of nitrogen. 相似文献
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Ordered mesoporous metal oxides: synthesis and applications 总被引:2,自引:0,他引:2
Great progress has been made in the preparation and application of ordered mesoporous metal oxides during the past decade. However, the applications of these novel and interesting materials have not been reviewed comprehensively in the literature. In the current review we first describe different methods for the preparation of ordered mesoporous metal oxides; we then review their applications in energy conversion and storage, catalysis, sensing, adsorption and separation. The correlations between the textural properties of ordered mesoporous metal oxides and their specific performance are highlighted in different examples, including the rate of Li intercalation, sensing, and the magnetic properties. These results demonstrate that the mesoporosity has a direct impact on the properties and potential applications of such materials. Although the scope of the current review is limited to ordered mesoporous metal oxides, we believe that the information may be useful for those working in a number of fields. 相似文献
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Thermal stability on a mixture of triblock polymer (P123) and fluorocarbon surfactant (FC-4) in acidic media for synthesis of ordered mesoporous materials has been carefully investigated by NMR spectroscopy at various treated temperatures (RT-180 degrees C) and the templating mechanism of the mixture on high-temperature synthesis has been proposed. Accordingly, we have designed fluorocarbon-free templates for syntheses of ordered mesoporous silica materials at high temperatures. As expected, ordered mesoporous silica materials with high degree of silica condensation are synthesized at high temperatures from these designed templates. 相似文献