New liquid-free proton conductive nanocomposite based on imidazole-functionalized cellulose nanofibers

Abstract

The first successful attempt to synthesize a new proton conducting polymeric nanocomposite film based on pure cellulose nanofibers (CNF) as a polymer matrix functionalized on their surface with imidazole molecules (Im) as a dopant, was made. The 2CNF-Im nanomaterial contains on average one molecule of imidazole per 2 glucose units from cellulose chains. Water evaporation and thermal stability of 2CNF-Im were studied by thermogravimetric analysis (TGA and DTG) and differential scanning calorimetry (DSC). The temperature dependence of electrical conductivity was studied by the impedance spectroscopy. At 140 °C, the 2CNF-Im nanocomposite has a maximum conductivity of 7.0 × 10−3 S/m, i.e. four orders of magnitude higher than that of non-functionalized CNF matrix. The newly synthesized cellulose nanocomposite exhibits high electrical and thermal stability. In 2CNF-Im, the activation energy of the proton transport process is the lowest compared to the previously synthesized imidazole-functionalized composites based on other pure cellulose materials and equals 0.62 eV. The synthesized nanomaterial is liquid-free solid polymer electrolyte showing proton conductivity above the boiling point of water.

Effect of Sintering Temperature and Polarization on the Dielectric and Electrical Properties of La0.9Sr0.1MnO3 Manganite in Alternating Current

“…Thus, the charges carriers need lower energy to jump between sites, since the hops occur over shorter distances. In addition, the jumps become realized towards higher levels [ 46 , 47 , 48 , 49 , 50 , 51 ] for T S = 1200 °C (JRM), which is in contrast to the horizontal translational motion in the classic models for T S = 800 and 1000 °C. Such a result shows the sensitivity of the conduction mechanism to the sintering temperature.…”

“…For this reason, the jump relaxation model (JRM) was used to explain this evolution in perovskites and amorphous materials [ 43 , 44 , 45 ]. This model tries to describe andvisualize the dynamics of the jumping motion as a function of space and time, where two opposing relaxation processes occur, which are successful jumps and unsuccessful jumps [ 46 , 47 , 48 , 49 , 50 , 51 ]. The physical significance of the JRM originated from the jumping motion of the ions in the atomic scale (ionic conductivity) [ 46 , 47 , 48 , 49 , 50 , 51 ].…”

“…This model tries to describe andvisualize the dynamics of the jumping motion as a function of space and time, where two opposing relaxation processes occur, which are successful jumps and unsuccessful jumps [ 46 , 47 , 48 , 49 , 50 , 51 ]. The physical significance of the JRM originated from the jumping motion of the ions in the atomic scale (ionic conductivity) [ 46 , 47 , 48 , 49 , 50 , 51 ]. According to the JR model, the displacement of the mobilized ions is explained in terms of the frequency effect.…”

“…As the frequency increases, the ion is temporarily out of equilibrium with respect to the distribution of the neighbors. In this case, two concurrent relaxation processes can be visualized (successful and unsuccessful jumps) [ 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 ]. Indeed, for the successful jumps, when an ion jumps to a new site, its neighboring ions relax and redistribute to establish a new equilibrium condition around the new site.…”

Electric and Dielectric Properties in Low-Frequency Fields of Composites Consisting of Silicone Rubber and Al Particles for Flexible Electronic Devices

“…As seen in Figure 8 , in the first region of the low frequency range, the measured conductivity decreases slowly by the decrease of frequency, tending to a constant value, which will not depend on the frequency, representing the DC component of conductivity (σ DC ) according with the Jonscher universal law [ 35 ]. The numerical values of the DC conductivity were determined based on the Nyquist impedance diagrams, Z″(Z′) in Figure 5 b) and the fit parameters (see Table 1 ) corresponding to the equivalent electrical model for each sample [ 34 , 36 ]. As a result, the values thus obtained for σ DC are listed in Table 1 .…”