Preparation and characterization of cellulose nanofiber cryogels as oil absorbents and enzymatic lipolysis scaffolds.

Cellulose nanofiber (CNF) materials have received much attention as sustainable “green” materials with high mechanical properties. Their application in oil absorption and enzymatic lipolysis makes them further attractive from the perspective of environmental issues including marine pollution preservation. Herein, we prepared CNF cryogels with various surface properties, evaluated their capacities as oil absorbents and applied them as lipase-lipolysis scaffolds. Their obtained cryogels consisted of various modified CNFs and their structure and properties were investigated. Moreover, lipase-supported CNF cryogels were prepared for enzymatic lipolysis. The cryogels of protonated TEMPO-oxidized CNF showed the highest absorption capacity for olive oil, while all the CNF cryogels possessed similar absorption abilities towards water. In enzymatic lipolysis with lipase, the TEMPO-oxidized CNF (TOCN-Na+) cryogel showed the highest specific activity. The specific activities of lipase in TOCN-Na+ cryogels remained unchanged after being stored at 40 °C for 3 days.