Redox-responsive polymeric membranes via supermolecular host–guest interactions

Redox-responsive materials have attracted much attention, and redox-responsive membrane is strongly desired since enormous numbers of redox reactions carry out in living systems. Herein, a novel polymeric membrane with redox-resposive hydraulic permeability is fabricated by introducing a reversible redox-responsive system based on the host–guest complex between ferrocene (Fc) and β-cyclodextrin (β-CD) into polyethersulfone (PES) membrane. As the result of reversible redox-responsive formation or deformation of the complex, the water flux for the membrane with 18.3   wt% redox-responsive materials was 270   mL/m 2   mmHg   h in original state, while increased to 1022   mL/m 2   mmHg   h in oxidation state and decreased to 538   mL/m 2   mmHg   h in reduction state. In addition, the results of water contact angle, surface zeta potential and the gas flow/liquid displacement confirmed that the origin of the redox-responsive hydraulic permeability were the change of the pore size and porosity for the modified membranes. The redox-responsive membranes have great potential to be utilized in the fields of chemical detection, drug delivery, biological treatments and so on.