Cross-linking cellulose nanofibrils for potential elastic cryo-structured gels
1 Paper and Fibre Research Institute (PFI), Høgskolerringen 6b, Trondheim, NO-7491, Norway
2 Department of Biotechnology, Lund University, P.O. Box 124, Lund, SE-22100, Sweden
Nanoscale Research Letters 2011, 6:626 doi:10.1186/1556-276X-6-626Published: 12 December 2011
Cellulose nanofibrils were produced from P. radiata kraft pulp fibers. The nanofibrillation was facilitated by applying 2,2,6,6-tetramethylpiperidinyl-1-oxyl-mediated oxidation as pretreatment. The oxidized nanofibrils were cross-linked with polyethyleneimine and poly N-isopropylacrylamide-co-allylamine-co-methylenebisacrylamide particles and were frozen to form cryo-structured gels. Samples of the gels were critical-point dried, and the corresponding structures were assessed with scanning electron microscopy. It appears that the aldehyde groups in the oxidized nanofibrils are suitable reaction sites for cross-linking. The cryo-structured materials were spongy, elastic, and thus capable of regaining their shape after a given pressure was released, indicating a successful cross-linking. These novel types of gels are considered potential candidates in biomedical and biotechnological applications.