Fabrication of dual-functional poly(ionic liquid) adsorptive membranes for enhanced artemisinin separation and antibacterial activities

Artemisinin has garnered significant research interest due to its potent antimalarial properties. The selective isolation of artemisinin from Artemisia annua L. remains technically challenging due to its low natural abundance and the cumbersome separation from co-extracted waxy oil. In this study, a series of novel poly(ionic liquid) (PIL) adsorptive membranes featuring varying alkyl chain lengths were synthesized by polymerization at room temperature. The PIL membranes were applied to separate artemisinin from waxy oil and the results demonstrated that the membranes exhibited outstanding purification performance. The PIL − 12 achieved rapid adsorption of waxy oil with a capacity of 358.49 mg/g within 40 min and the purity of artemisinin exceeded 99 % after a single crystallization step under optimal conditions. Moreover, the PIL-12 still possessed excellent separation for artemisinin after six cycles. The purification mechanism was investigated through both experimental and theoretical simulation approaches, revealing that the PIL membrane simultaneously adsorbed multiple waxy oil components via electrostatic forces and hydrogen bonding interactions. Moreover, the PIL adsorptive membranes displayed strong antibacterial activity against E. coli and S. aureus . This study provides critical design strategies and novel insights for the separation of bioactive compounds from traditional Chinese medicines.