Shape memory poly(ionic liquid) gels controlled by host–guest interaction with β-cyclodextrin

Shape memory poly(ionic liquid) (PIL) gels with controllable macroscopic swelling degrees were prepared via host–guest interaction in this work. PILs with bis(trifluoromethyl-sulfonyl)imide (TFSI−) anions were synthesized by the radical copolymerization and immersed in water and β-cyclodextrins (β-CD) aqueous solutions, respectively. Quick swelling and shape memory behavior of the PIL gel were observed in β-CD aqueous solution due to the hydrophobic-to-hydrophilic transition induced by β-CD/TFSI− inclusion complexes. However, the PIL gel undergone only a slight swelling in the presence of water. The swelling of inclusion-sensitive polymer networks with shape memory effect prepared in this work would have applications in advanced sensor and biomedicine.