Author(s)

Bilquis Ibrahim Adham¹, H. M. El-Khair^1,2

¹Department of Physics, Faculty of Science and Technology, Al Neelain University, Khartoum, Sudan.
²Comittee on Radiation and Environmental Pollution Protect (CREPP), Department of Physics, College of Science, Al Imam Mohammad Ibn Saud Islamic University (IMSIU), Riyadh, KSA.

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.

Graphite, Polymers, Composites, Temperature Dependence, Diffusion Mecha-nism

Adham, B. and El-Khair, H. (2018) Atomic Diffusion and Electric Conductivity of Gum Arabic/Graphite Composite. Journal of Materials Science and Chemical Engineering, 6, 91-96. doi: 10.4236/msce.2018.67010.