Resumo (PT):
Abstract (EN):
The adsorption isotherms of nitrogen, oxygen and argon in four VA-class hydrophobic dipeptides are
presented. Isotherms were determined at 5, 20 and 35 1C, for a pressure range of 0–6 bar. Under these
conditions, adsorption is still in the Henry region. For all materials and temperatures, the sequence
of preferential adsorption is Ar 4 O2 4 N2, a highly abnormal result. At 5 1C, the dipeptide with the
smallest pores, VI, has Ar/O2 adsorption equilibrium selectivities up to 1.30, the highest ever measured in
Ag-free adsorbents. Gas uptakes, at 1 bar and 20 1C, are B0.05 mol kg1
, very low relative values that
are partially explained by the low porosity of the solids (o10%). The significance of these results for the
development of new materials for the process of O2 generation by pressure swing adsorption (PSA) is
discussed. The results indicate some of the structural and chemical properties that prospective Ag-free
adsorbents should have in order to have Ar/O2 selectivity, hydrophobic pores, less than 0.5 nm-wide,
and porosity of, at least, 20%.
Idioma:
Inglês
Tipo (Avaliação Docente):
Científica
Notas:
Publicação abrangida pelo Journal Citation Reports 2015
Nº de páginas:
8