Controlled cross-linking and tailored affinity characteristic of Janus silica nanosheets hydrogel via pickering high internal phase emulsions (HIPEs) system for high-accuracy separation of naringin

Selective separation and purification of flavoniods from agricultural wastes has become a prominent topic due to the promising clinical application potential and green and sustainable development needs. Recently, various efforts have been devoted to the development of amphiphilic silica nanosheet sorbents. However, there are still challenges in promoting stable selectivity and rapid mass transfer. Therefore, we prepared a novel hydrogel by embedding Janus silica nanosheets as a stabilized particle into a porous carrier via Pickering HIPEs system. Janus silica nanosheets (J-SNS) with hydrophobic surface (end-capped with vinyl) and hydrophilic surface (end-capped with amino) were prepared by ultrasonication of Janus composite aerogels produced via interfacial sol–gel process. Then, the imprinted polymer was modified onto the hydrophobic surface of J-SNS by precipitation polymerization using naringin (NRG) as the template molecule and 3-acrylamidophenylboronic acid as the functional monomer. Subsequently, chitosan was attached to the hydrophilic surface of J-SNS-MIPs by amidation reaction between citric acid carboxyl group and amino group to enhance the emulsion interface crosslinking polymerization. The prepared PHs@J-SNS-MIPs not only showed fast adsorption (120 min) and excellent enrichment of NRG (40.88 μmol g⁻¹), but also showed good selectivity (imprinting factor 2.76) and regeneration performance (efficiency of 92.04 % after 6 cycles). Additionally, the extraction rate of coarse NRG via PHs@J-SNS-MIPs was 92.28 %. Remarkably, the purified NRG solutions displayed lasting antibacterial performance against Staphylococcus aureus (S. aureus) with inhibition zone of 13.25 mm and 11.06 mm, respectively. Therefore, the PHs@J-SNS-MIPs could be potentially developed as a feasible and efficient sorbent to achieve the goals of green sustainable chemistry for selective separation and purification of high-value natural flavoniods from agricultural wastes.