title: New gas chromatographic instrumentation for studying the action of sulfur dioxide on marbles.
abstract: Reversed-flow gas chromatography, which is a sub-technique of inverse gas chromatography, is an experimental arrangement simulating a simple model for the action of air pollutants on buildings and monuments, in laboratory scale. By using a commercial gas chromatograph and an appropriate mathematical analysis, kinetic parameters such as rate constants for adsorption k1, adsorption/desorption kR and surface reaction k2, as well as surface diffusion coefficients Dgamma, deposition velocities Vd and reaction probabilities gamma of SO2 on marble surfaces at different temperatures (303.15-353.15 K) in the presence or in the absence of protective materials (an acrylic copolymer, Paraloid B-72 or a siloxane, CTS Silo 111) were calculated. From the above mentioned physicochemical quantities the ability of the examined materials to minimize the dry deposition of SO2 on marble is carrying out and a possible mechanism for the interaction between SO2 and Paraloid B-72 was suggested. Both materials (CTS SILO 111 and Paraloid B-72) are good enough for protecting marble against SO2 at low temperatures (303.15-323.15), while at high temperatures (333.15-353.15), siloxane seems to protect marble better than acrylic copolymer.
authors.affiliation: Department of Chemistry, University of Patras, GR-26504 Patras, Greece.
authors.forename: Nikolaos
authors.initials: N
authors.lastname: Bakaoukas
authors.forename: John
authors.initials: J
authors.lastname: Kapolos
authors.forename: Athanasia
authors.initials: A
authors.lastname: Koliadima
authors.forename: George
authors.initials: G
authors.lastname: Karaiskakis
mesh_terms: D002119:Calcium Carbonate / Q000737:chemistry*; D002849:Chromatography, Gas / Q000295:instrumentation*; D013458:Sulfur Dioxide / Q000737:chemistry*
chemical_list: D013458:Sulfur Dioxide; D002119:Calcium Carbonate