摘要

As reported in our previous work, crosslinked polymeric adsorbents with high microporous surface areas are proper for glabridin adsorption. In addition, adsorption capacity of the microporous and mesoporous self-crosslinked polystyrene resin XT2-10 was superior to that of the optimal commercial adsorbent BMKB-1 under the same conditions. However, there is still room for further improvement. Based on this, in the following study, a series of novel hypercrosslinked polymeric adsorbents modified with acetylaniline as the cross-linked bridge (labeled as XT8-0, XT8-4, XT8-6, XT8-8 and XT8-10) were synthesized from macroporous crosslinked chloromethylated polystyrene by adding different quantity of acetylaniline in the Friedel-Crafts reaction. The microporous surface areas of hypercrosslinked polymeric resins XT8 occupied more than 55% of the total BET surface areas and these resins were evaluated for adsorption of glabridin. Among the synthesized five resins, XT8-8 possessed the largest adsorption capacity toward glabridin, and it was superior to the previous synthesized self-crosslinked polystyrene resin XT2-10 and much better than the optimal commercial resin BMKB-1. The isotherms could be fitted by Freundlich model and the adsorption was shown to be an exothermic process. The kinetic curves could be characterized by pseudo-second-order rate equation and the adsorption rate of glabridin on XT8-8 was controlled by both intraparticle diffusion and external diffusion. The enthalpy Delta H, Gibb's free energy Delta G and entropy Delta S were calculated to be negative. The reusability of the modified resins was also assessed and the modified resins exhibited considerable reusability. The remarkable adsorption behaviors of XT8-8 were due to its suitable structural design and modification. The hypercrosslinked resins being developed were promising alternatives to commercial adsorbents for adsorbing glabridin and other flavones from herbal plants.