Preparation of nanoporous cellulose foams from cellulose-ionic liquid solutions

Nanoporous cellulose foams have been successfully prepared by a procedure in three steps: (i) dissolving in a room temperature ionic liquid (1-butyl-3-methylimidazolium chloride): (ii) coagulation in water; (iii) rapid freeze drying using liquid N-2. The results show that the foam had a 3D open fibrillar network structure with the specific surface area as high as 186.0 m(2)/g and a porosity of 99%. Moreover, the cellulose foam shows cellulose II crystalline structure. Cellulose concentration in hydrogel as well as drying methods influences upon the structure and pore size of cellulose foams. (C) 2009 Elsevier B.V. All rights reserved.