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 den sity, tensile strength, and electrical resistivity were measured. The SEM p hotos of fibers containing silver (at initial concentrations of 1000 and 10 000 ppm) were similar. to those of non-activated carbon fibers at high lev el burn-off. Silver particles accelerate the activation rate. However, the specific surface areas of silver-containing activated carbon fibers were si milar to those of non-silver containing activated carbon fibers. The appare nt density and the tensile strength of the 10 000 ppm silver-containing car bon fibers were 1.677g/cm(3) and 24 kg(f)/mm(2), and these decreased to 0.7 95 g/cm(3) and 6 kg(f)/mm(2) respectively, at 69% burn-off. The electrical resistivity of isotropic pitch-based carbon fiber was 97 mu Omega m. By com parison, as the initial silver content of the fiber was increased to 1000 a nd 10 000 ppm, the resistivity decreased to 69 and 57 mu Omega m, respectiv ely. These resistivities depended on the total pore volume and increased ex ponentially with increasing specific surface area of fibers. (C) 1999 Elsev ier Science Ltd. All rights reserved.