Physical properties of silver-containing pitch-based activated carbon fibers

Silver-containing pitch-based carbon fibers were prepared and activated in steam. SEM and TEM were used to investigate the surface morphology and the behavior of the silver particles in fibers. Physical properties such as density, tensile strength, and electrical resistivity were measured. The SEM photos of fibers containing silver (at initial concentrations of 1000 and 10 000 ppm) were similar to those of non-activated carbon fibers at high level burn-off. Silver particles accelerate the activation rate. However, the specific surface areas of silver-containing activated carbon fibers were similar to those of non-silver containing activated carbon fibers. The apparent density and the tensile strength of the 10 000 ppm silver-containing carbon fibers were 1.677g/cm³ and 24 kg_f/mm², and these decreased to 0.795 g/cm³ and 6 kg_f/mm², respectively, at 69% burn-off. The electrical resistivity of isotropic pitch-based carbon fiber was 97 μΩ m. By comparison, as the initial silver content of the fiber was increased to 1000 and 10 000 ppm, the resistivity decreased to 69 and 57 μΩ m, respectively. These resistivities depended on the total pore volume and increased exponentially with increasing specific surface area of fibers.