A new emulsion method to synthesize well-defined mesoporous particles
A new emulsion method to synthesize well-defined mesoporous particles
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DOI：
10.1016/j.jcis.2003.08.056
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发表时间：
2004-03-15
影响因子：
9.9
通讯作者：
Wang, YJ
中科院分区：
文献类型：
--
作者：
Guo, W;Luo, GS;Wang, YJ
本工作探索了一种以聚合物PEG为溶胀剂制备有序介孔材料的新乳液方法。讨论了合成条件，包括链长和PEG浓度、老化时间、乳液种类以及溶胀剂添加到反应体系中的时间。结果表明，利用乳液法的优点，可以很好地控制成核和生长。与水热法生产的颗粒相比，乳液法生产的颗粒更加均匀且不易团聚。添加不同分子量的PEG作为溶胀剂时，孔径变化不大：以4 nm左右为中心，分布较窄。当使用不同浓度的 PEG 时，BET 表面积、孔径和孔体积发生变化。综上所述，在介孔材料的形成过程中，PEG等聚合物不仅可以通过改变浓度来控制3~70 nm的孔径，还可以通过聚合物的链长来调节颗粒的结构、改善颗粒的形貌。通过调节溶胀剂的添加时间，制备出孔壳介孔材料。该方法对于那些严格要求颗粒均匀性的应用尤其重要，例如色谱分离。 (C) 2003 Elsevier Inc. 保留所有权利。
A new emulsion method for preparing ordered mesoporous materials with polymer PEG as the swelling agent has been explored in the present work. The synthesis conditions including the chain length and the PEG concentration, the duration of aging, the kind of emulsion, and the time when the swelling agents were added to the reaction system are discussed. The results show that with the advantage of the emulsion method, the nucleation and growth were controlled very well. The nicely spherical particles produced by the emulsion method were more uniform and less prone to agglomerate than those produced through the hydrothermal method. When different MW PEG were added as swelling agents, the pore size changed little: it was centered around 4 nm and had a narrow distribution. When different concentrations of PEG were applied, BET surface area, pore size, and pore volume changed. To summarize, in the formation of mesoporous materials, polymers such as PEG can not only control the pore size from 3 to 70 nm through variation of concentration, but also regulate the structures and improve the morphology of particles by the chain length of polymers. By adjusting the time of addition of the swelling agents, a poroshell mesoporous material was prepared. This method is particularly important for those applications that strictly require particle uniformity, such as chromatography separation. (C) 2003 Elsevier Inc. All rights reserved.