Spin-labelling studies of benzene sorbed in carbon particles using muonium: a molecular view of sorption by environmental carbons

When benzene is sorbed into activated carbon powder, two distinct fractions are found using longitudinal field muon spin relaxation measurements, and are characterized by activation energies of 6 and 26 kJ mol(-1) in respect of molecular reorientation. This is due to location of benzene in large (me so and macro) pores and micropores, respectively; escape from the latter is accompanied by a large, positive activation entropy of +52 J mol(-1) K-1. Copyright (C) 2000 John Wiley & Sons, Ltd.