title: On the role of organic adlayers in the anomalous water sorptivity of Lépine limestone.
abstract: Sorptivity data are reported for the capillary absorption of water, ethanol, propan-2-ol, and n-heptane by the calcitic limestone Lépine (Lavoux à grain). The data confirm that the water sorptivity is anomalously low, an indication of partial wetting by water. Results are expressed in terms of a wetting index. The water sorptivity increases after heat treatment and chemical oxidation by hydrogen peroxide bleaching, while the sorptivity with organic liquids is unchanged. These treatments, therefore, increase the water wetting index. The results provide strong evidence that the presence of a natural organic adlayer is responsible for the anomalously low water sorptivity of this particular limestone. This natural water repellency effect may be exploited in developing chemical treatments to modify the water transport properties of stone.
authors.affiliation: School of Mechanical, Aerospace and Civil Engineering, The University of Manchester, PO Box 88, M60 1QD, UK. ioannis@ucy.ac.cy
authors.forename: Ioannis
authors.initials: I
authors.lastname: Ioannou
authors.forename: William D
authors.initials: WD
authors.lastname: Hoff
authors.forename: Christopher
authors.initials: C
authors.lastname: Hall
mesh_terms: D000327:Adsorption; D000438:Alcohols / Q000737:chemistry*; D002119:Calcium Carbonate / Q000737:chemistry*; D006536:Heptanes / Q000737:chemistry*; D006358:Hot Temperature; D006861:Hydrogen Peroxide / Q000737:chemistry; D010084:Oxidation-Reduction; D013499:Surface Properties; D014867:Water / Q000737:chemistry*
chemical_list: D000438:Alcohols; D006536:Heptanes; D014867:Water; C028618:n-heptane; D006861:Hydrogen Peroxide; D002119:Calcium Carbonate