(168d) Composite CNT-Biopolymer Capacitive Porous Fibers

To address the need for multifunctional textile fibers that serve as both electrochemically functional and mechanically durable fibers for energy storage and sensing, carbon nanotube (CNT)-biopolymer solutions were syringe needle extruded into a chemical crosslinking solution of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) and ethylenediamine to facilitate covalent amide bond linkages between the biopolymers and oxidized CNTs.¹ Different ratios of cellulose nanofibers, alginate, and DNA relative to CNTs were used to tune fiber porosity, conductivity, tensile strength, stiffness, and elasticity. After extrusion, covalent crosslinking, rinsing, and ethanol solvent exchange, fibers were either ambiently or supercritically dried to compare material and electrochemical properties. To further increase specific capacitance via pseudocapacitance, nickel oxide nanoparticles were electrolessly deposited on the CNT-biopolymer composite fibers before rinsing and drying.² Resulting composite fibers were characterized with Fourier transform-infrared spectroscopy (FTIR), scanning electron and optical microscopy, nitrogen gas adsorption-desorption, electrochemical impedance spectroscopy, and cyclic voltammetry. The ability to synthesize fiber materials as three-dimensional porous nanostructures with mechanical durability enables control of surface area, pore size and mass transfer properties, electronic conductivity, and ultimately device integration. The covalently crosslinked CNT-biopolymer composite fibers with tunable porosity via ambient or supercritical drying techniques and metal/metal oxide functionalization provides a common material platform for a broad range of noble and transition metals for catalytic, energy storage, and sensing applications.

*Corresponding: F. John Burpo, Email: john.burpo@westpoint.edu

References

1. Burpo, F.J., Mitropoulos, A.N., Nagelli, E.A., Palmer, J.L., Morris, L.A., Ryu, M.Y., Wickiser, J.K. Cellulose Nanofiber Biotemplated Palladium Aerogels. Molecules. 2018, 23, 1405-1418.

2. Ohmura, J., Burpo, F.J., Lescott, C., Ransil, A., Yoon, Y., Records, W., Belcher, A. Highly adjustable 3D nano-architectures and chemistries via assembled 1D biological templates. Nanoscale, 2019, 11, 1091-1102.