Preparation of cesium ion sieve composite material and its adsorption properties of Cs+

Abstract

In the previous work, our research group adopted sol-gel technology to incorporate trace Zn²⁺ into the Ti–O lattice of Cs₂Ti₆O₁₃ to improve the cell structure and prepared zinc-doped titanate precursor material (CZnTO). This precursor is acid-treated to form a zinc-doped protonated titanate (HZnTO). Based on previous studies in our research group, this paper proposed a membrane support and creating technology for preparing powdered zinc-doped titanium-based cesium ion sieves. It made a batch adsorption test to explore the adsorption performance of Cs⁺. The main research contents are as follows: A phase transition synthesis method is used to composite PVDF material with powdered ion sieve HZnTO to form a microporous hydrophobic polymer membrane HZnTO@PVDF. The higher the pH in the solution, the greater its saturated adsorption capacity. The composite membrane maintains good stability in both acidic and alkaline solutions. Compared with the powdered ion sieves, HZnTO@PVDF the adsorption rate is significantly faster, reaching saturated adsorption capacity in about 2 h in 3000 mg/L Cs⁺ solution. HZnTO @ PVDF has good cyclic adsorption stability, maintaining 90.33 % of the initial adsorption capacity after five adsorption-desorption cycles. Moreover, after 5 cycles, the composite membrane still maintained the integrity of its original structure.