Adsorption of aspirin on the macropore resin with six functional group sites: Multiple functional group sites in macropore resin versus the micropore filling in hypercrosslinked resin

Abstract

Glucosamine modified macropore resin with six functional group sites (denoted as MG-6), 2-aminopyridine modified macropore resin with two functional groups sites (denoted as MG-2) and a hypercrosslinked resin with the micropore filling and zero functional group sites (denoted as HG-0) were synthesized. XAD-4 was chosen as the representative of macroporous resin with zero functional groups sites (denoted as MG-0). The effects of the multiple functional group sites in macropore resin versus the micropore filling in hypercrosslinked resin on the adsorption of aspirin were investigated. The adsorption capacities of aspirin followed the order: six functional group sites > micropore filling > two functional group sites > zero functional group sites. The adsorption rate constants k1 followed the order: zero functional group sites > six functional group sites ≈ two functional group sites > micropore filling. MG-6 with six functional group sites showed greater adsorption capacity and faster adsorption rate than those of HG-0 with the micropore filling. Corresponding to their functional groups, the four resins (HG-0, MG-0, MG-2 and MG-6) exhibited the different adsorption mechanism of aspirin. As compared qmax of aspirin in the literatures, the adsorption capacity of aspirin on MG-6 was much higher than that of the reported adsorbents.