Novel cellulose nanofibers/barium titanate nanoparticles nanocomposites and their electrical properties

Abstract

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.

Synthesis and characterization high purity alumina nanorods by a novel and simple method using nanocellulose aerogel template

“…The thickness of the prepared NFC was in the range of 3–5 nm while the length was several microns. The obtained NFC thickness is in accordance with previously prepared NFC from other lignocellulosic materials such as palm, rice straw, and wood [19, 30, 32, 33].

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“…To prepare porous nanocellulose aerogel, nanofibrillatred cellulose (NFC) was first isolated from bagasse by chemical treatment of bagasse pulp with 2,2,6,6-tetramethyl-1-piperidinyloxy radical, sodium bromide, and sodium hypochlorite as previously described [30]: Bleached pulp (3 g) was dispersed in distilled water (400 mL) with TEMPO (0.048 g, 0.3 mmol) and sodium bromide (0.48 g, 4.8 mmol). Then, 30 mL of sodium hypochlorite solution was then added with stirring, and the pH was adjusted to 10.…”

Flexible high dielectric thin films based on cellulose nanofibrils and acid oxidized multi-walled carbon nanotubes

“…And this process can be accelerated by higher frequency. 12,53 Interestingly, the composite lm with 6.2 wt% of o-MWCNT exhibits lower s AC than that of pure CNF. At 1 kHz, the s AC decreases from 3.15 Â 10 À7 S cm À1 for CNF to 1.77 Â 10 À7 S cm À1 for CNF/MWCNT (6.2 wt%).…”

“…However, the P r of the composite lm is close to P s , suggesting a low efficiency of energy storage. 12 The polarization of the CNF/MWCNT lms saturates before the electric eld reaches its maximum value. It may be caused by the leakage current, which is the result of a heterogeneous structure and partial conductive network.…”

Addition of microcrystalline cellulose to an alkyd resin/titanium dioxide film: effect on dielectric properties

“…Until now, several polymer/ceramic composites have been obtained (e.g. epoxy resin-barium titanate [9], cellulose nanofibers/barium titanate [10], acrylonitrile-butadiene rubber/barium titanate [11]), but the most studied pairs are based on Polyvinylidene Fluoride (PVDF) and Barium Titanate and, in some cases, coupling agents [8,12,13,14,15]. However, these composites do not perform as expected.…”