Synthesis Of Bimodal Open-Porous Polystyrene Monoliths With Glycopolymer Surfaces For High-Speed Protein Chromatography

Conventional polystyrene (PS) monoliths are rarely used for separation of biomacromolecules due to their heterogeneous skeletons and hydrophobic surfaces. In this work, high-permeable and bimodal open-porous polystyrene monoliths (BOPMs) with homogeneous skeletons and glycopolymer surfaces were prepared by reversible addition-fragmentation chain transfer (RAFT) polymerization via an emulsion-templating method. The stable and bicontinuous medium-internal phase emulsion (MIPE) was stabilized by the cooperative assembly of two surfactants, that is, a self-made amphiphilic diblock glycopolymer (ADG) in the oil phase and Pluronic F127 (PF127) in the water phase. It was found that the higher hydrophilic-lipophilic balance (HLB) value of ADGs needs to match the higher concentration of PF127 to promise the homogeneous structure of the bicontinuous MIPE. A possible mechanism was proposed based on the hydrogen bonding interaction. Using the MIPE as a template, BOPMs were successfully synthesized by RAFT emulsion polymerization. The effects of the HLB value and adding amount of ADGs on the morphology of the BOPM were also studied. There are two sets of pores in the BOPM determined by mercury porosimetry, that is, gigapores (200-7000 nm) and mesopores (20-100 nm). Taking advantage of glycopolymer surfaces of the BOPM, glycoprotein can be directly separated at a mobile-phase velocity of up to 1806 cm/h in the hydrophilic interaction liquid chromatography mode. The BOPM as prepared shows good permeability, mechanical stability, and biocompatibility, which is an ideal support in high-speed protein chromatography, cell culture, and enzyme immobilization.