Spongelike Functional Materials from TEMPO-Oxidized Cellulose Nanofibers

The cleavage of the hierarchical structure of plant cellulose provides nanocellulose (NC), an attractive renewable nanomaterial for advanced applications. The presence of carboxylic acid moieties renders 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)-oxidized cellulose nanofibers (TOCNF) particularly appealing for the synthesis of cellulose-based polymers with suitable cross-linkers. This chapter aims to provide an overview on the synthesis of bPEI-TOCNF sponges and their possible application fields. The high specific content of amino groups in bPEI-TOCNF makes them very suitable for environmental applications. The nanostructuring of cellulose nanofibers can also represent a useful synthetic tool for the preparation of different families of organic and inorganic aerogels. The cross-linking of TOCNF, in the presence of polyamines, provides a simple and cheap thermal procedure for the production of nanostructured aerogels from polysaccharide renewable sources. The ecofriendly nature of the engineered nanostructured materials opens the route for the development of sustainable and ecosafe nanoremediation, overcoming the issues related to the use of nanosized technologies.