Influence of sulfation pretreatment on the structure and properties of cellulose nanofibrils

In order to achieve the regulation preparation of sulfated cellulose nanofibrils, a series of sulfated conditions was carried out to investigate the features and the potential application in nanoparticles dispersion. The morphology and surface features of the sulfated cellulose nanofibrils were characterized by means of Fourier transform infrared spectroscopy , atomic force microscope, transmission electron microscope , X-ray diffraction, elemental analysis, thermo-gravimetric analysis, etc. The results showed that the yield of the obtained sulfated cellulose nanofibrils can be high up to 96.9%. Besides, the sulfated cellulose nanofibrils showed a width and length in range of 3–8 nm and 200–800 nm, respectively, exhibiting the aspect ratio of about 100. Moreover, the zeta potential, degree of substitution and degree of polymerization were in range of − 57.5–−79.1 mV, 0.11–0.48, and 131–570, respectively, and could be tailored by variation of reagent molar ratio, reaction temperature and time during sulfation pretreatment . Notably, the sulfated cellulose nanofibrils showed great potential to be served as good dispersions for nanoparticles, which could make the dispersion of carbon nanotubes and nano zinc oxide stable for more than half a month. • A high yield up to 96.9 % of nanofibrils sulfated by sulfamic acid was obtained. • The features of sulfated nanofibrils were regulated by the sulfation conditions. • The sulfated nanofibrils showed an excellent dispersity for CNTs and nano ZnO.