Chemical Doping of Cellulose Nanocrystal

Abstract

Cellulose nanocrystal (CNC) has received great interest as sustainable green materials, owing to their intrinsic properties such as renewability, and abundance. It has attractive features, such as large specific surface area, low density, transparency, high tensile stiffness and strength, high thermal stability, and biocompatibility. CNC is extracted from forest and agro-biomass by mechanical or chemical treatments, which has rod-like shape with lengths varying between 100 and 600 nm, and diameters ranging between 2 and 20 nm. However, CNC is basically an insulator due to its high band gap, its applications to electronic devices are limited. We have investigated a doping method that can improve the electrical conductivity of CNC for electronic applications. Among carbon based materials, such as carbon nanotube or graphene, reduced sheet resistance and improved electrical conductivity by chemical doping have been reported. Based on the results of these studies, we designed chemical doping experiments to CNC. Generally, molecules with electron-withdrawing groups adsorbed on the surface of carbon materials serve as p-type dopants. The selected materials for p-type dopants were doped to CNC and the optical- and electrical properties were characterized. We believe this work is a valuable concept demonstrating that CNC plays a new material for future electronic applications. -This work was supported by Electronics and Telecommunications Research Institute(ETRI) grant funded by the Korean government (19ZB1510).