ISSN 1017-2548(Print)
ISSN 2234-8530(Online)
Volume 48, Number 2
JKCSEZ 48(2)
April 20, 2004 

Titanium and [titanium+Na(K)] substituted 11Å tobermorites solids synthesized under hydrothermal conditions at 180℃ exhibit cation exchange properties toward heavy transition metal cations, such as Fe²⁺, Zn²⁺, Cd²⁺ and/or Pb²⁺. The amount of heavy metal cations taken up by these solids was found in the order: Fe²⁺>Zn²⁺>Cd²⁺>Pb²⁺, and reached maximum at 10% [Ti+K]-substituted tobermorite. The total cation exchange capacity of the 10% Ti+Na (K) - substituted tobermorites synthesized here range from 71 to 89 meq/100 g, and 50-56 meq/100g for Ti-substituted only. Results indicated that 10% [Ti+K] substitution exhibit cation exchange capacity more 2.4 times than the unsubstituted-tobermorite. This is due to the increase of the number of active sites on the exchangers. The incorporation of Ti and/or [Ti+Na(K)] in the lattice structure of synthesized tobermorites is due to exchange of Ti⁴⁺⇔2Ca²⁺ and/or Ti⁴⁺+2Na⁺ (K⁺)⇔3Ca²⁺, respectively. The mechanism of Ti and [Ti+Na(K)] incorporations in the crystal lattice of the solids during synthesis and the heavy metal cations uptaken by these solids is studied.