In this work, we had adopted solid states reaction kinetic model to calculate diffusion coefficient of graphite Gr in Gum Arabic (GA) as the function of temperatures and concentration? D(t, C). From the calculations w...In this work, we had adopted solid states reaction kinetic model to calculate diffusion coefficient of graphite Gr in Gum Arabic (GA) as the function of temperatures and concentration? D(t, C). From the calculations we have found that the diffusion coefficient D increases with increasing temperature. At higher temperature the Gr atoms might get enough thermal energy to overcome the activation energy (Ea) barrier and hence can easily be transported to a new atomic position. Diffusion coefficient of Gr at high concentrations had exceeded that at low concentrations by more than two to three orders of magnitude. Such increase can be attributed to the large number of jumps or jump frequency which found to be directly proportion to the Gr concentration. Electric conductivity, calculated by Nernst-Einstein equation, at high concentration Gr had exceeded that at lower concentration. The decrease in conductivity with decreasing Gr concentration might be attributed to the effective charges interactions, which lead to enhance the recombination of charge carriers.展开更多
In this study, Gum Arabic (GA)/Graphite (Gr) composite material was prepared using solid state reaction method. The FTIR peaks obtained were referred to the binding of Gr with the active groups in GA, such as NH2, COO...In this study, Gum Arabic (GA)/Graphite (Gr) composite material was prepared using solid state reaction method. The FTIR peaks obtained were referred to the binding of Gr with the active groups in GA, such as NH2, COOH, CHO, CNC (alkyl amine) and C=CH (aromatic monosubstitution). Atomic diffusivity of Gr in GA was calculated using simple model and was found to varied randomly. This randomness might be due to the attachment of Gr with different active groups of GA. The addition of Gr results in improvement of the conductivity of GA to a far extend as it reaches the semiconductor range. The random variation in conductivities of the samples can be attributed to the effect of high frequency range, where the effect of phonon-electron is dominant. The samples subjected to the impedance spectroscopy (IS) for second and third time were acquired different diffusivities as well as conductivities. Such variations might indicate that IS was a processing technique similar to thermal treatment since it boosted the Gr atomic diffusion.展开更多
文摘In this work, we had adopted solid states reaction kinetic model to calculate diffusion coefficient of graphite Gr in Gum Arabic (GA) as the function of temperatures and concentration? D(t, C). From the calculations we have found that the diffusion coefficient D increases with increasing temperature. At higher temperature the Gr atoms might get enough thermal energy to overcome the activation energy (Ea) barrier and hence can easily be transported to a new atomic position. Diffusion coefficient of Gr at high concentrations had exceeded that at low concentrations by more than two to three orders of magnitude. Such increase can be attributed to the large number of jumps or jump frequency which found to be directly proportion to the Gr concentration. Electric conductivity, calculated by Nernst-Einstein equation, at high concentration Gr had exceeded that at lower concentration. The decrease in conductivity with decreasing Gr concentration might be attributed to the effective charges interactions, which lead to enhance the recombination of charge carriers.
文摘In this study, Gum Arabic (GA)/Graphite (Gr) composite material was prepared using solid state reaction method. The FTIR peaks obtained were referred to the binding of Gr with the active groups in GA, such as NH2, COOH, CHO, CNC (alkyl amine) and C=CH (aromatic monosubstitution). Atomic diffusivity of Gr in GA was calculated using simple model and was found to varied randomly. This randomness might be due to the attachment of Gr with different active groups of GA. The addition of Gr results in improvement of the conductivity of GA to a far extend as it reaches the semiconductor range. The random variation in conductivities of the samples can be attributed to the effect of high frequency range, where the effect of phonon-electron is dominant. The samples subjected to the impedance spectroscopy (IS) for second and third time were acquired different diffusivities as well as conductivities. Such variations might indicate that IS was a processing technique similar to thermal treatment since it boosted the Gr atomic diffusion.
