Increasing the separation efficiency of tanshinone homologs using a micro-chromatographic membrane prepared from poly(ionic liquid) nanoparticles

Membranes are widely used for separating bioactive molecules, and ionic-liquid-based membranes have new applications for separating structurally similar homologs. However, these applications are limited by low separation efficiencies and poor reusability. In this study, poly(ionic liquid) (PIL) nanoparticle were successfully prepared via emulsion polymerization and deposited onto a base membrane to prepare a microchromatographically supported membrane. The ability of the membrane to separate tanshinone homologs (tanshinone I and tanshinone IIA) was evaluated. A maximum tanshinone selectivity of 60.7 % was obtained under optimal conditions, with preferential filtration of tanshinone ⅡA and rejection of tanshinone I, which is significantly distinct from the small different of adsorption effect between PIL on the two types of tanshinones under static adsorption conditions. This membrane achieved rapid and effective separation of tanshinones and exhibited favorable water flux through its microchromatographic structure. This membrane based on PILs nanoparticle has the potential to separate other structurally similar homologs. • Poly(ionic liquids)-based nanospheres were prepared by emulsion polymerization. • Nanospheres-based membrane was used for tanshinone homologs separation. • A maximal selectivity of 60.7 % was obtained for tanshinone homologs. • This membrane possesses good physical and chemical properties.