Electrical conductivity and dielectric properties of nanofibrillated cellulose thin films from bagasse

Abstract

AbstractNanocelluloses are potential candidates for applications in flexible electronic due to their unique physical and mechanical properties. However, electrical properties of these materials have not investigated thoroughly to study their electrical properties. In the current work, electrical properties of nanocellulose films prepared from bagasse pulp were studied and compared with those of bagasse pulp fibers. Two kinds of nanocelluloses were used in the current study: microfibrillated cellulose (MFC) and TEMPO‐oxidized nanofibrillated cellulose (NFC). The crystallinity, grain size, and morphology of the different nanocelluloses were studied using X‐ray diffraction and transmission electron microscopy techniques. The dc‐, ac‐ electrical conductivity, dielectric constant ɛ′, and dielectric loss ɛ″ of non‐plasticized and glycerol‐plasticized nanocellulose films were studied in the temperature range from 298 to 373 K and in the frequency range from 0.1 KHz to 5 MHz. The results showed that the dc‐ electrical conductivity verifies Arrhenius equation and the activation energies varied in the range of 0.9 to 0.42 eV. Ac‐electrical conductivity increased with frequency and fitted with power law equation, which ensures that the conduction goes through hopping mechanism. The dielectric constant decreased with increasing frequency and increased with increasing temperature, probably due to the free movement of dipole molecular chains within the cellulose fiber. Glycerol‐plasticized NFC (NFC‐G) film had the highest dielectric constant and ac‐electrical conductivity values of 79 800 and 2.80× 10−3ohm−1 cm−1, respectively. The high values of dielectric constant and conductivity of the prepared films support their use in electronic components.