ZEOLITIC BEHAVIOR IN STUFFED SILICA POLYMORPHS

Alkali-metal aluminosilicates with the quartz, cristobalite and tridym ite structures possess zeolitic behaviour when imperfectly crystallise d. In aqueous solution these novel materials display a level of cation exchange which is comparable with synthetic zeolites. In contrast, wh en they are well crystallised these stuffed silica polymorphs, as they are also known, do not possess this cation exchange behaviour. They c an be prepared simply from clay minerals and have potential as inexpen sive inorganic cation exchangers.