Fabrication of tailored carboxymethyl-functionalized cellulose nanofibers via chemo-mechanical process from waste cotton textile

As an importance resource from domestic garbage, waste cotton textiles have great potential to be recycled for high value-added products. Herein, carboxymethyl cellulose nanofibers (CM-CNFs) were obtained from waste cotton fibers by carboxymethyl modification and followed mechanical nano-defibrillation. The high yield of 98% can be realized in our CM-CNFs. The morphology and properties of CM-CNFs were characterized by means of atomic force microscopy (AFM), Fourier infrared spectroscopy (FT-IR), X-ray diffraction (XRD) analysis, and UV−visible spectroscopy etc. The results showed CM-CNFs have the aspect ratio ranged from 32 to 340 and the degree of polymerization (DP) from 371 to 779, which could be tailored by the degree of substitution (DS, 0.13–0.70) during carboxymethyl modification process. The high zeta-potential (−78 – −95) endowed the CM-CNFs suspension with good chemical stability and it can be stored for several months. In addition, the CM-CNFs can be served as good dispersion for carbon nanotubes due to the highly charged groups on its surface.