Dissolution of Zeolite in Acidic and Alkaline Aqueous Solutions As Revealed by AFM Imaging
Dissolution of Zeolite in Acidic and Alkaline Aqueous Solutions As Revealed by AFM Imaging
复制标题
AFM 成像显示沸石在酸性和碱性水溶液中的溶解
DOI：
--
复制
发表时间：
1996
期刊：
影响因子：
--
通讯作者：
H. Nozoye
中科院分区：
文献类型：
--
作者：
Sadaaki Yamamoto;Shoko Sugiyama;O. Matsuoka;K. Kohmura;T. Honda;and Yasuyuki Banno;H. Nozoye
原子力显微镜 (AFM) 可以直接检测沸石表面的形态变化，这些变化是晶体在室温下浸入碱性 (0.1 N NaOH) 或酸性 (0.2 N H2SO4) 水溶液时因溶解而产生的。 AFM 图像首次揭示，对于片沸石（一种天然沸石晶体），（i）NaOH 攻击（100）表面的铝硅酸盐的最上层，留下孤立或聚集的岛，（ii）类似地，H2SO4 攻击（010）表面，形成凹坑，（iii）两种溶液都没有发生步退。这种独特的溶解模式，即片沸石的铝硅酸盐层从阶地逐层溶解，是由片沸石的特征性孔隙结构产生的。这种微观水平的分析对于进一步开发新的沸石结构至关重要，而新的沸石结构对于这一类重要材料的活性至关重要。
Atomic force microscopy (AFM) makes it possible to directly detect morphological changes on the surface of a zeolite that are due to dissolution when the crystal is immersed in either an alkaline (0.1 N NaOH) or acidic (0.2 N H2SO4) aqueous solution at room temperature. The AFM images revealed for the first time that for heulandite (a natural zeolite crystal) (i) NaOH attacked the uppermost layer of aluminosilicate of the (100) surface, leaving isolated or agglomerated islands, (ii) similarly, H2SO4 attacked the (010) surface, forming pits, and (iii) step retreat did not occur for either solution. This unique dissolution pattern, in which the aluminosilicate layers of heulandite dissolve from terraces layer-by-layer, results from the characteristic pore structure of heulandite. This microscopic-level analysis should prove vital in the further development of new zeolite structures, which are critical to the activity of this important class of materials.