Adsorption hysteresis in self-ordered nanoporous alumina.
We performed systematic adsorption studies using self-ordered nanoporous anodic aluminum oxide (AAO) in an extended range of mean pore diameters and with different pore topologies. These matrices were characterized by straight cylindrical pores having a narrow pore size distribution and no interconnections. Pronounced hysteresis loops between adsorption and desorption cycles were observed even in the case of pores closed at one end. These results are in contrast with macroscopic theoretical models and detailed numerical simulations of the adsorption in a single pore. Extensive measurements involving adsorption isotherms, reversal curves, and subloops carried out in closed-bottom pores suggest that the pores do not desorb independently from one another.
Bruschi
Lorenzo
L
Dipartimento di Fisica G.Galilei, Universita di Padova, via Marzolo 8, 35131 Padova, Italy.
Fois
Giovanni
G
Mistura
Giampaolo
G
Sklarek
Kornelia
K
Hillebrand
Reinald
R
Steinhart
Martin
M
Gösele
Ulrich
U