Sustainability of Multiwall Carbon Nanotube Fibers and Their Cellulose Composite

Nowadays, the research community envisions smart materials composed of biodegradable, biocompatible, and sustainable natural polymers, such as cellulose. Most applications of cellulose electroactive materials are developed for energy storage and sensors, while only a few are reported for linear actuators. Therefore, we introduce here cellulose-multiwall carbon nanotube composite (Cell-CNT) fibers compared with pristine multiwall carbon nanotube (CNT) fibers made by dielectrophoresis (DEP) in their linear actuation in an organic electrolyte. Electrochemical measurements (cyclic voltammetry, square wave potential steps, and chronopotentiometry) were performed with electromechanical deformation (EMD) measurements. The linear actuation of Cell-CNT outperformed the main actuation at discharging, having 7.9 kPa stress and 0.062% strain, making this composite more sustainable in smart materials, textiles, or robotics. The CNT fiber depends on scan rates switching from mixed actuation to main expansion at negative charging. The CNT fiber-specific capacitance was much enhanced with 278 F g(-1), and had a capacity retention of 96% after 5000 cycles, making this fiber more sustainable in energy storage than the Cell-CNT fiber. The fiber samples were characterized by scanning electron microscopy (SEM), BET (Braunauer-Emmett-Teller) measurement, energy dispersive X-ray (EDX) spectroscopy, FTIR, and Raman spectroscopy.