TEMPO oxidized cellulose nanofibers from electrospun regenerated cellulose: Processing feasibility and application potentials.

2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) oxidized cellulose nanofiber (TOCN) as an ecofriendly 1D nano-unit has been endowed with infinite possibilities to prepare a variety of functional materials. However, its wide applications have been significantly restricted due to complicated preparation processes from natural wood precursor with low production yield and severe contamination. Herein, we propose to mass produce regenerated TOCN (rTOCN) using electrospun cellulose acetate nanofiber (CANF) as precursor. It was illustrated that regenerated cellulose nanofibers (rCNF) obtained from deacetylated CANF could be readily converted to rTOCN with the width of ~300 nm by TEMPO when the oxidation time was shorter than 140 min. When further prolonging processing time, rCNF would be over-oxidized to cellouronic acid. The obtained rTOCN had equivalent capabilities with natural wood derived TOCN to improve the mechanical and thermal properties of the polymer matrix as the reinforcing filler, to improve the dispersion of the carbon nanotubes in hydrogel as the compatibilizer, as well as to prepare functional 1D nanomaterial as the template. Furthermore, rTOCN assisted carbon nanotubes incorporated hydrogel could be further utilized as conductive strain sensor and electromagnetic interference shielding material. This study can direct an alternative mean to prepare TOCN with large amount and long length.