A novel lithium ion-imprinted membrane with robust adsorption capacity and anti-fouling property based on the uniform multilayered interlayer

Effective modification strategies contribute to high adsorption capacity , separation efficiency and anti-fouling properties of ion-imprinted membranes. The design of a homogeneous and hydrophilic interlayer between the substrate membrane and ion-imprinted layer is crucial factor for the excellent performance of ion-imprinted membranes. In this study, a novel multilayered interlayer (SiO 2 @SP-PDA) was developed and uniformly coated on the substrate surface (PVDF membrane). The polydopamine (PDA) prepared via oxidation of sodium periodate (SP-PDA) increases the uniformity of SiO 2 @SP-PDA modification, which reduces the agglomeration of the ion-imprinted layer, and thereby boosts the adsorption capacity to 231.77 mg·g −1 . The prepared ion-imprinted membrane (SiO 2 @SP-PDA-IIM) exhibits a favorable anti-fouling property due to the incremental hydrophilicity and the presence of SiO 2 nano interlayer. Based on the XDLVO theory, it can be deduced that the SiO 2 modification increases the membrane surface electron donor tension (γ − ), which plays an essential role in enhancing the anti-fouling property of SiO 2 @SP-PDA-IIM. In this paper, the design of multilayered structure is of great significance to make the ion-imprinted membrane be a potential candidate for Li + efficient separation in natural water.