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    Please use this identifier to cite or link to this item: http://ir.lib.ncu.edu.tw/handle/987654321/4107


    Title: MFI奈米沸石粒子的再分散性;Dispersion of calcined MFI nanocrystals
    Authors: 周怡全;Yi-Chuan Chou
    Contributors: 化學工程與材料工程研究所
    Keywords: 奈米沸石;形貌;分散性;zeolite;nanocrystals;morphology;dispersion
    Date: 2009-07-24
    Issue Date: 2009-09-21 12:31:12 (UTC+8)
    Publisher: 國立中央大學圖書館
    Abstract: 本實驗室過去已經建立一套奈米沸石silicalite-1 的合成方法,可製作出大小50-60nm、粒徑分佈均一的沸石粒子。顯微鏡觀察後,發現此類沸石粒子是由許多微小結晶(10-20nm)所團聚而成,表面凹凸不平且輪廓並不規則。因此屬於團聚二次粒子。此類的奈米沸石,即使經過數次的離心清洗,煆燒後的再分散性仍然不佳。可能是表面有太多可縮合氫氧基的關係。本研究是以過去的合成方法為基礎 加以修改,製作出尺寸與過去相近,但形貌相異的沸石粒子。此類沸石粒子表面較為平滑,且輪廓較為明確,甚至出現類似單晶的菱角,與先前無序團聚粒子的形貌有明顯不同。然後將試圖從各種儀器的分析中,比較兩種不同形貌奈米粒子的差異,然後推敲產生不同結構的反應機制。此外,在新的合成方法中,調整反應條件可以合成出尺寸由次微米到數十奈米且都有類單晶形貌的沸石粒子,也對這些大小不同的類單晶沸石做一系列的分析,以界定其與真正單晶的異同。最後,我們發現類單晶粒子經過離心清洗及煆燒後,再分散性明顯優於先前之團聚粒子。因此,可以由此途徑製作出去模版後仍可分散於有機溶劑的沸石粒子,未來將可與高分子混成製作低折射率材料。 A rapid synthesis procedure for silicalite nanocrystals was developed in our laboratory in the past. Theses nanocrystals were agglomerates composed of many 10-20nm primary units that do not have any regular shape. The poor dispensability of these agglomerates after calcination may come from the excessive silanol groups on the surface of these agglomerates. In this study, the previous synthesis procedures were modified to produce silicalite nanocrystals with similar size but of different morphology. The new nanocrystals were rigid particles with well-defined crystal facets. The difference in morphology is believed to be originated from different growth mechanism. The well-shaped nanocrystals were much better dispersed after calcination than the agglomerated ones. The well-shaped template-free nanocrystals could be further functionalized by silanes and disperse in organic solvent such as IPA and MEK, aiming at forming a nanocomposite with organic polymers
    Appears in Collections:[化學工程與材料工程研究所] 博碩士論文

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