Adsorption of nitrogen and water vapour by activated Kevlar® chars

Mechanism of Adsorption of Water in Carbon Micropores As Revealed by a Study of Activated Carbon Fibers

“…Hence, the starting relative pressure and shape of the isotherm are functions of both micropore size and surface chemical properties (in this case, oxygenated groups). Similar results are found by other researchers, 32,36,42,46,86 who also suggested that micropore size distribution is important in determining the shape of water isotherms. The major or minor influence that oxygenated groups exercise depends principally on the micropore size.…”

Activated carbon fibers with a high content of surface functional groups by phosphoric acid activation of PPTA

“…Detailed examination of the isotherm corresponding to the sample prepared at the lowest impregnation ratio (KP5 750) shows that it exhibits low pressure hysteresis (LPH). The LPH is attributed to two types of phenomena: swelling of non-rigid walls in pores with trapping of adsorbate molecules [22], and/or retention of molecules in pores similar in size to them [37]. In this case, the retention of molecules can be the appropriate explanation of the LPH, because this sample has a great proportion of ultramicropores as can be concluded from the fact that V lp (DR, CO 2 ) > V lp (DR, N 2 ).…”

Porous Texture Evolution in Nomex-Derived Activated Carbon Fibers

“…Thus, Freeman et al (3,4) first reported on the outstanding homogeneity in pore size of ACFs prepared from highly ordered polymers, such as aramid fibers. Indeed, ACFs prepared from aramid show a narrower pore size distribution than those reported in the literature (5) for ACFs derived from more disordered precursors.…”