title: Scanning of Adsorption Hysteresis In Situ with Small Angle X-Ray Scattering.
abstract: Everett's theorem-6 of the domain theory was examined by conducting adsorption in situ with small angle x-ray scattering (SAXS) supplemented by the contrast matching technique. The study focuses on the spectrum differences of a point to which the system arrives from different scanning paths. It is noted that according to this theorem at a common point the system has similar macroscopic properties. Furthermore it was examined the memory string of the system. We concluded that opposite to theorem-6: a) at a common point the system can reach in a finite (not an infinite) number of ways, b) a correction for the thickness of the adsorbed film prior to capillary condensation is necessary, and c) the scattering curves although at high-Q values coincide, at low-Q values are different indicating different microscopic states. That is, at a common point the system holds different metastable states sustained by hysteresis effects. These metastable states are the ones which highlight the way of a system back to a return point memory (RPM). Entering the hysteresis loop from different RPMs different histories are implanted to the paths toward the common point. Although in general the memory points refer to relaxation phenomena, they also constitute a characteristic feature of capillary condensation. Analogies of the no-passing rule and the adiabaticity assumption in the frame of adsorption hysteresis are discussed.
authors.affiliation: Hephaestus Laboratory, Department of Petroleum and Mechanical Engineering, Eastern Macedonia and Thrace Institute of Technology, Cavala, St. Lucas 654 04, Greece.
authors.forename: Athanasios Ch
authors.initials: AC
authors.lastname: Mitropoulos
authors.affiliation: Membranes and Materials for Environmental Separations Laboratory, Institute of Nanoscience and Nanotechnology, National Centre for Scientific Research "Demokritos", Ag. Paraskevi, 153 41, Athens, Greece.
authors.forename: Evangelos P
authors.initials: EP
authors.lastname: Favvas
authors.affiliation: Membranes and Materials for Environmental Separations Laboratory, Institute of Nanoscience and Nanotechnology, National Centre for Scientific Research "Demokritos", Ag. Paraskevi, 153 41, Athens, Greece.
authors.forename: Konstantinos L
authors.initials: KL
authors.lastname: Stefanopoulos
authors.affiliation: Hephaestus Laboratory, Department of Petroleum and Mechanical Engineering, Eastern Macedonia and Thrace Institute of Technology, Cavala, St. Lucas 654 04, Greece.|Department of Chemistry, Laboratory of Adsorption and Catalysis, University of Antwerp, Universiteitsplein 1, B2610 Wilrijk, Belgium.
authors.forename: Etienne F
authors.initials: EF
authors.lastname: Vansant
mesh_terms: D000327:Adsorption; D008962:Models, Theoretical; D053838:Scattering, Small Angle; D014961:X-Ray Diffraction