ADSORPTION - DESORPTION PROPERTIES OF SORBENTS.
Abstract:
Adsorption and desorption isotherms of nitrogen at 77.7 K are reported for an activated viscose carbon fiber felt. The surface area is comparable to that of a previously studied activated carbon fiber made from Fortisan, but higher than that of a sample of coal base granular carbon, also previously studied See AD-430 569. Pore distribution analysis shows that the viscose felt has much less volume in pores in the 40-1000A radius range than the others. Adsorption and desorption isotherms of dimethyl methylphosphonate, DMMP, are reported for 25 C for all three sorbents mentioned and for 35 C for the viscose felt. Total micropore volumes determined from the nitrogen and DMMP isotherms are reported for the three sorbents discussed. Smaller values are obtained with DMMP in all cases suggesting that screening of DMMP from certain pores, accessible to the smaller nitrogen molecule, is taking place. Apparatus for the measurement of rates of adsorption and desorption at constant pressure is described. It is based on the Cahn electrobalance. Diffraction measurements on the Fortisan carbon fiber indicate that it is essentially amorphous to X-rays. An oxygen surface group determination is reported for the Fortisan carbon felt. Author