Adsorption of nitrogen and water vapour by activated Nomex® chars

Abstract

Fibrous activated carbons were prepared from Nomex® poly(m-phenylene isophthalamide), in the form of a commercially available woven textile. After carbonisation in nitrogen and activation in either carbon dioxide or steam to varying burn-offs at 1123 K, the resultant activated chars were characterised by nitrogen adsorption, water sorption, and elemental analysis. It appears that the carbonisation and activation of Nomex produced chars that were highly microporous, with little pore widening occurring even at high percentage burn-offs. Differences between the chars activated in the two gases were observed and particular attention was directed towards the study of differences between Nomex chars and the materials previously prepared from the related polymer, Kevlar®. It was found that Nomex and Kevlar chars had quite distinctive adsorptive properties, which appear to be related to their characteristic pore structures and to the presence of metal and nitrogen residues. © 1995.