Elucidating the porous and chemical structures of ZnCl2-activated polyacrylonitrile on a fiberglass substrate

Abstract

ZnCl2-activated polyacrylonitrile (PAN) coated onto a fiberglass substrate was prepared in N2 at 450 °C. The porous and chemical structures were characterized by using N2 adsorption at 77 K, XPS, FTIR, competitive adsorption of CO2/CH4 and the adsorption of Cs+, Sr2+ and Ag+. The activated PAN displays a high BET surface area up to 1012 m2 g−1, a broad mesopore size distribution as well as a major micropore size distribution. Up to 19.3 wt% of nitrogen, which is probably in the form of pyridinic and pyrrolic structures, is incorporated in the chemically activated PAN. HCl uptake results show that such a material has a higher amount of weakly basic functional groups compared to a commercially available ACF15. The activated PAN also exhibits a higher selectivity coefficient for CO2/CH4 at STP and higher adsorption amounts for Cs+, Sr2+ and Ag+ than ACF15. It is proposed that nitrogen-containing, weakly basic functional groups positioned on the suitable-sized pore walls improve the adsorption ability of the activated PAN toward CO2, Cs+, Sr2+ and Ag+.