Activated carbon materials of uniform porosity from polyaramid fibers

Activated carbon fibers derived from polyaramids exhibit an outstandingly homogeneous pore size distribution. Here, we review the work carried out on the porosity characteristics of carbons prepared from these polymers, specifically Kevlar [poly(p-phenylene terephthalamide)] and Nomex [poly(m-phenylene isophthalamide)]. First, studies on the thermal decomposition of both polyaramid fibers and the reactivity of the resulting chars are reviewed in connection with the properties of the resulting products. Then, the porous texture of activated carbon fibers (ACFs) prepared by different methods (physical and chemical activation) is examined, with particular emphasis on the use of some novel methods to investigate microporosity in solids. Finally, the relationship between porosity and behavior of polyaramid-based carbons in several different types of application is analyzed.