Polyethyleneimine modified heterostructure porous polymer microspheres for efficient adsorption of acteoside

Abstract

Acteoside (ACT) is a bioactive component, which has potential applications in the fields of food, health care, medicine, etc. The development of adsorbents that can efficiently and selectively adsorb ACT is still challenging. Here, polyethyleneimine (PEI) modified heterostructure porous polymer microspheres (HPPM@PEI) were designed and synthesized via a double emulsion interfacial polymerization strategy for efficient adsorption of ACT. HPPM@PEI possessed porous structure with a large pore volume of 1.58 m3/g, and PEI moiety was identified on the interior pores and external surface of the microspheres. PEI played two significant roles in the adsorption performance of HPPM@PEI. First, the introduced PEI increased pore volume and specific surface area of HPPM@PEI to provide more adsorption sites. Second, the PEI on interior pores and external surface allowed pH to regulate adsorption capacity and selectivity for ACT on HPPM@PEI-1.0/600/2g. The experimental results indicated that HPPM@PEI-1.0/600/2g exhibited the highest adsorption capacity of 138.26 ± 8.7 mg/g and selectivity of 6.01 ± 0.16. The adsorption process of ACT can be fitted by pseudo-second-order kinetic and Langmuir isotherm models. The adsorption mechanisms proposed that electrostatic attraction, hydrogen bonding, π-π stacking, and van del Waals were the main interaction forces between HPPM@PEI-1.0/600/2g and ACT. This work proposes a novel strategy to synthesize polymer microspheres with large pore volume and high specific surface area for efficient adsorption of bioactive components from plants.