Impact of double cryogelation process on a macroporous dye-affinity hydrogel

Cryogels with interconnected channels allow high flow-through properties and mass transfer when dealing with complex mixtures such as non-clarified crude extracts. However, their mechanical strength can be challenged due to a large void volume inside the polymeric network. We have addressed this problem by forming a double-layer cryogel applied as a dye-affinity chromatography gel. In this study, poly(acrylamide-co-allyl glycidyl ether) cryogel was prepared at sub-zero temperature. The second layer was then prepared inside the primary cryogel under the same conditions to form a double-layer network. Cibacron Blue F3GA, a dye molecule, was immobilized on the surface of the cryogels. Bovine serum albumin was used as a model molecule to study the adsorption/elution procedure in batch and continuous modes. The maximum batch binding capacity and the dynamic binding capacity for the single-layer cryogel were 18 and 0.11, and for the double-layer cryogel were 7.5 and 0.9 mg/g of gel, respectively. However, the mechanical stability of the double-layer cryogel increased 7-fold (144 kPa). It was found that the kinetic and adsorption isotherms follow pseudo-second-order and Freundlich models, respectively. The regeneration of the columns after adsorption/elution cycles was evaluated, and no significant loss of capacity was observed after 10 cycles.