Gor, Gennady Y.Gennady Y.GorHuber, PatrickPatrickHuberWeissmüller, JörgJörgWeissmüller2019-03-112019-03-112018-08-31Physical Review Materials 8 (2): 086002 (2018-08-31)http://hdl.handle.net/11420/2090Adsorption-induced deformation of porous materials is the generation of strains in a solid due to its interaction with adsorbing fluids. The theoretical description of adsorption-induced deformation often relies on the so-called solvation pressure, the normal component of a pressure tensor in the liquid adsorbed in the pore. Recent measurements of adsorption-induced strains in two dimensions require a description that allows for the deformation to be anisotropic. Here, we present such a description. We refrain from using the solvation pressure concept and instead base the discussion on a phenomenological description of coupled mechanics and adsorption that has well-established links to continuum mechanics. We find that our approach captures all relevant features of anisotropic sorption strain; the approach thus provides a useful alternative to the solvation pressure concept. We derive analytical expressions for the stress-strain relations in a model porous material with an array of parallel channel-like pores of high aspect ratio (length/width). These relations include separate terms from the liquid pressure, from the surface stress at the liquid-solid interface, and from a spreading tension at the solid-liquid-vapor triple line. Surface stress and liquid pressure contribute to the strains along and normal to the pore axis in a qualitatively different manner. The underlying discussion of capillary forces sheds light on the variation of the surface stress during adsorption and capillary condensation.en2475-995320188Art.-Nr. 086002APShttp://rightsstatements.org/vocab/InC/1.0/PhysikTechnikIngenieurwissenschaftenJournal Articleurn:nbn:de:gbv:830-882.02766410.15480/882.208610.1103/PhysRevMaterials.2.08600210.15480/882.2086Journal Article