Nanocelluloses 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. Glycerolplasticized NFC (NFC-G) film had the highest dielectric constant and acelectrical conductivity values of 79 800 and 2.80× 10 −3 ohm −1 cm −1 , respectively. The high values of dielectric constant and conductivity of the prepared films support their use in electronic components.

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Green nanocomposite films from cellulose nanofibers/barium titanate (CNF/BT) with high homogeneity were successfully prepared by doping different ratio of BT nanoparticles (2.5 to 25 wt%) into CNF. Scanning electron microscope images showed homogenous distribution of BT in the CNF matrix. Thermogravimetric analysis results showed good thermal stability of the prepared nanocomposites. X‐ray diffraction analysis showed that the tetragonality of BT grains was retained in the composite samples. Addition of BT nanoparticles to CNF resulted in decreasing the tensile strength properties of the films. The dielectric properties were analyzed in detail with respect to frequency ranged from 0.1 Hz to 5 MHz, temperature ranged from 289 to 373 K, and BT loading. The high k values of the CNF/BT films were attributed to spontaneous polarization of BT particles. The dielectric constant of the nanocomposites increased by addition of BT nanoparticles up to 5 wt% and decreased afterwards. Hopping ionic conduction was proved as a conduction mechanism of the prepared nanocomposites. The activation energy of the conduction ranged from 0.4 to 0.08 eV. Moreover, the values of activation energy decreased as the doping level of BT nanoparticles increased.

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The infrared spectra of xanthated cellulose and its blends with polyvinyl alcohol (PVA) in different ratios were investigated. The dielectric constant, loss tangent, and AC-conductivity of the prepared blends were measured at different temperatures (293-373K) in the frequency range (100 Hz-5 MHz). The decrease in the dielectric constant " 0 was observed with increasing frequency due to dielectric dispersion. On the other hand, the dielectric constant was increased by increasing both PVA percentage in the blend and temperature, which related to the polar nature of polyvinyl alcohol. A loss peak was observed in the power factor (tan d) spectra, which referred ORDER REPRINTS to the relaxation, arises from the orientation of polar groups. AC-conductivity was also studied. The results were interpreted in terms of electronic conduction via hopping processes.

Bulk superconductor samples of YBa 2 Cu 3 O 7−δ (YBCO) doped with nano metal oxides of Mn 3 O 4 , Co 3 O 4 , Cr 2 O 3 , CuO and SnO 2 respectively with 0.2 wt% are synthesized by a solid-state reaction route. The structural characterization of all samples has been carried out by x-ray diffraction (XRD) and scanning electron microscopy (SEM) and transmission electron microscopy (TEM) techniques. The XRD patterns indicate that the magnetic doping of nano metal oxides Mn O , Co O , Cr O 3 4 3 4 2 3( ) gives a high value of orthorhombicity of the YBCO samples which is the result of high oxygen content, and consequently could give better superconducting properties contrary to the non magnetic nano oxides (CuO, SnO 2 ). The critical temperature (T c ) of the studied samples was found to improve by nano magnetic doping and lower with nano nonmagnetic doping. The superconducting transition temperature Tc determined from electrical resistivity measurements was found to increase for Mn 3 O 4 (5.27 μB) doping and decrease for other metal oxides doping.

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