Versatile cellular foams derived from CNC-stabilized Pickering emulsions

Abstract

Lightweight cellular foams were prepared by freeze-drying oil-in-water emulsions stabilized with cellulose nanocrystals (CNCs). Oil and water were removed while preserving the cellular emulsion template without any shrinkage or deformation both at the internal cell and bulk foam scales. This versatile process proved to be relevant for controlling the pore size of the foam with respect to emulsion droplets. Moreover, the composite foams could easily be obtained as shown here by the addition of polyelectrolytes. Mechanical properties of the foam were investigated and they were found to be reinforced by chitosan addition. Thus, our finding opens new routes to a broad range of cellulose-based porous materials.