A multifunctional and sustainable poly(ionic liquid)-quaternized chitosan hydrogel with thermal-triggered reversible adhesion.

A quaternized chitosan (QCS)@poly(ionic liquid) (PIL) hydrogel adhesive was prepared by in-situ ultraviolet (UV)-induced copolymerization of 1-vinyl-3-butyl imidazolium bromide ([BVIm][Br]) and methacryloyloxyethyl trimethylammonium chloride (DMC) in QCS aqueous solution without using any crosslinkers, which was stably crosslinked by reversible hydrogen bonding together with ion association and exhibited excellent adhesion, plasticity, conductivity and recyclability properties. Moreover, its thermal/pH-responsive behaviors and intermolecular interaction mechanism of thermal-triggered reversible adhesion were discovered, meanwhile good biocompatibility, antibacterial properties, repeated stickiness and degradability were also proved. The results showed that the newly developed hydrogel could make various tissues, organic, inorganic or metal materials adhered tightly within 1 min; after 10 binding-peeling cycles, the adhesive strength to glass, plastic, aluminum and porcine skin still remained beyond 96 %, 98 %, 92 % and 71 % of the original, respectively.

Ionic liquid@β-cyclodextrin-gelatin composite membrane for effective separation of tea polyphenols from green tea.

A new kind of multi-component membrane was prepared by combining gelatin solution, porogen and an inclusion complex of ionic liquid (IL) and beta-cyclodextrin (β-CD) in a simple physical manner for selective separation of tea polyphenols (TPs) from green tea crude extracts. After screening, it was found that the resulting membrane containing the IL of dicationic N-vinylimidazole proline salt ([VIm]C[l-pro]) had the excellent performance for the enrichment of the target molecules. Then the newly-developed film was comprehensively characterized by scanning electron microscopy, conductivity, thermogravimetry and spectral analysis.