Novel mesoporous silica spheres with ultra-large pore sizes and their application in protein separation

A series of novel mesoporous silica materials with ultra-large pores (20 to 40 nm in size), interconnected channel structure, thick walls (15 to 20 nm), high hydrothermal stability and selective protein adsorption were synthesized via a new synthetic strategy. We used Brij-56 and Brij-97 as templates and ethyl acetate (EA) and dimethyl o-phthalate (DOP) as additives in a neutral pH system to afford three novel spherical mesoporous silica materials (denoted as B-56-E-20, B-56-D-33 and B-97-D-40) having controllable, interconnected mesoscale channels with diameters of 20, 33 and 40 nm, respectively. The products have shown effective performance in size-selective adsorption of biomacromolecules, demonstrating great potentials in biomacromolecular separation. The molecular weight ranges of the proteins selectively adsorbed in B-56-E-20, B-56-D-33 and B-97-D-40 are 50-55, 60-65 and 70-100 KDa, respectively. Moreover, the products show good hydrothermal stability and can maintain the mesostructure in boiling water over 5 days. This work has bridged the gap in the synthesis of ultra-large pore between mesoporous and macroporous biomaterials and their application in biomacromolecular separation.