Synthesis of novel ion-imprinted polymers by two different RAFT polymerization strategies for the removal of Cs(I) from aqueous solutions

In this work, two novel Cs(I) ion-imprinted polymers (Cs(I)-IIP1 and Cs(I)-IIP2) have been prepared by surface imprinting technique based on support matrix of SBA-15. The strategy was carried out by introducing two different reversible addition–fragmentation chain transfer (RAFT) polymerization including using the free RAFT agent in solution and surface-anchored RAFT agent with appropriate initiation method, which is expected to generate a well-defined surface ion-imprinted polymer with excellent adsorption capacity. The materials were verified by FT-IR, SEM, TEM, nitrogen adsorption–desorption and TGA. Owing to the intrinsic advantages of surface-anchored RAFT polymerization, the resultant surface ion-imprinted polymer (Cs(I)-IIP2) exhibited more homogeneous and thinner polymer layer (15 nm) with excellent macrostructure in comparison to Cs(I)-IIP1 (75 nm) prepared by using the free RAFT agent in solution. Furthermore, the adsorption capacity of both polymers are compared, indicating that Cs(I)-IIP2 displays higher adsorption property and excellent selectivity for Cs(I).