Effects of multiwalled carbon nanotubes and reduced graphene oxide of different proportions on the electrothermal properties of cationic cellulose nanofibril-based composites

Cationic cellulose nanofibril (CCNF)-based electrothermal composites were successfully fabricated using simple ultrasonic dispersion and vacuum filtration of cationic cellulose nanofibril mixtures with 40 wt% mixed carbon fillers of different proportions of multiwalled carbon nanotube (MWCNT) and reduced graphene oxide (RGO). The motivation of this study was to investigate the electrothermal synergetic effect of different proportions of nanocarbon filler on the CCNF matrix. The results showed that MWCNT and RGO were evenly dispersed within the CCNF matrix, forming a multidimensional conductive network. The composites were endowed with high electrical conductivity from 1.17 S/cm to 7.58 S/cm and demonstrated an advantageous correlation of voltage–current and electric power–voltage with increasing MWCNT in the mixed carbon fillers. The electrothermal composite exhibited a remarkable heating and cooling response and electrothermal stability, and the efficient heating temperature for a ratio of MWCNT to RGO of 35:5 reached 102.15 °C at an applied voltage of 18 V. Furthermore, the mixed use of MWCNT and RGO effectively improved the electrothermal performance, its average electrothermal response time was less than 43.32 s, and the electrical power consumed was 32.85 mW/°C. This electrothermal composite has promising applications in eco-friendly and flexible resistance heating electronics.