High-strength and low-crystallinity cellulose/agarose composite microspheres: Fabrication, characterization and protein adsorption

• A novel strategy is proposed to prepare cellulose-based adsorbents for protein. • The adsorbents show high specific surface area and improved mechanical property. • The modified adsorbents exhibit excellent performance for protein separation. Cellulose derived adsorbent has attracted increasing interest owing to its low production cost, easy modification and biocompatibility. However, the intrinsic deficiencies of cellulose, including weak mechanical property and high crystallinity, seriously compromise the separation efficiency. To overcome these issues, a pre-cross-linking method together with the hybridization of agarose is proposed for constructing high-strength and low-crystallinity cellulose-based microspheres. Through the pre-crosslinking method, the crosslinking reaction between polysaccharides and epichlorohydrin is homogeneous, which endows the microspheres with high mechanical strength for better recyclability. Meanwhile, the introduction of agarose disorders the ordered aggregation of cellulose, by which more amorphous regions are created for high specific surface area. Finally, after being modified with 2-diethylethylamine hydrochloride, the proposed anionic adsorbent showed both high maximum adsorption capacities (BSA: 307.6 mg g −1 ; BHb: 161.4 mg g −1 ). Together with excellent mechanical stability, the proposed cellulose/agarose composite microspheres have a great potential in protein separation.