The Effect of Temperature on Electric Conductivity of Polyacrylonitrile-Polyaniline Fibers

The article presents an analysis of the influence of temperature on the electrical conductivity of composite polyacrylonitrile-polyaniline fibers (PAN/PANI). The fibers are obtained by synthesizing polyaniline directly in the spinning solution of fiber-forming polyacrylonitrile and characterized by X-Ray Diffraction (XRD), Differential Scanning Calorimetry (DSC), Scanning Electron Microscopy (SEM) methods. Electrical characterization of fibers is performed by current-voltage characteristic. The polarizing voltage of the electrodes in the range from -1 V to 1 V with a speed of 100 mV/sec is changed cyclically and linearly while simultaneously the current is measured. The current-voltage characteristic of the fibers is recorded at various temperatures in the range from -15 °C to 100 °C for 30 min. Based on the measurements, temperature changes in the conductance are determined in constant relative humidity. The current-voltage characteristics of the fibers in the ambient atmosphere with a relative humidity of 38 % are linear and symmetrical, which indicates the electron nature of the conductivity and the ohmic contact of the electrode-fiber. The characteristic of temperature conductance changes is not of a typical shape, it is parabolic. The conductance of the developed PAN/PANI fibers at 22 °C is about 1.50·10
^-4
S (6.7 kΩ) and decreases below and above this temperature. The analysis of research results and literature data enables the determination of individual factors affecting changes in conductance of the tested composite fiber.