On the selectivity regulation of K2ZrSi3O9•H2O-type ion exchangers
On the selectivity regulation of K2ZrSi3O9•H2O-type ion exchangers
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DOI：
10.1016/s0022-2860(98)00482-7
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发表时间：
1998-10-13
影响因子：
3.8
通讯作者：
Khainakov, SA
中科院分区：
文献类型：
--
作者：
Clearfield, A;Bortun, AI;Khainakov, SA
一系列混合的钾锆钛硅酸盐，通式为K2MSi3O9。H2O（其中M = Zr、Ti），含有不同量的钛和锆（0至100%at.）水热合成。所有这些化合物具有包含两种类型的通道的骨架结构，其尺寸平滑地变化，即，随着化合物中钛含量的增加而减小。两个通道，具有22元环开口的小通道和具有16元环开口的大通道，沿c轴沿着延伸，并且它们在垂直方向上经由14元环开口彼此连接。这为整个通道系统创造了三维开口，使阳离子易于迁移。研究了K_2MSi_3O_9. H2O和质子形式的两个末端成员的家庭，K0.3H1.7TiSi3O9。2H（2）O和K_（0.5）H_（15）ZrSi_3O_9。2H（2）O对碱金属离子的选择性，发现交换剂组成（孔道尺寸）与对某些离子的选择性之间存在明显的相关性，具有大孔道的富锆硅酸盐对铷和铯离子表现出亲合性，而具有小得多的孔道的富钛硅酸盐对钾离子表现出亲合性。(C)1998 Elsevier Science B.V.保留所有权利。
A series of mixed potassium zirconium-titanium silicates of the general formula K2MSi3O9. H2O (where M = Zr, Ti), containing different amounts of titanium and zirconium (from 0 to 100% at.) were synthesized hydrothermally. All these compounds have a framework structure containing two types of channels the size of which smoothly changes, namely, decreases with the increase of titanium content in the compound. Both channels, small channels with a 22-membered ring opening and large ones with a 16-membered ring opening, run along the c-axis and they are connected to each other via a 14-membered ring opening in the perpendicular direction. This creates three-dimensional openings for the total channel system that enables easy cation migration. The ion exchange behavior of K2MSi3O9. H2O and protonic forms of two end members of the family, K0.3H1.7TiSi3O9. 2H(2)O and K0.5H15ZrSi3O9. 2H(2)O, towards alkali metal ions was studied and a distinct correlation between the exchanger composition (channels size) and selectivity to certain ions was found. Zirconium-rich silicates with large channels exhibit affinity for rubidium and cesium ions, whereas titanium-rich compounds with much smaller channels show a preference for potassium ion. (C) 1998 Elsevier Science B.V. All rights reserved.