Diffusion potentials in porous mortar in a moisture state below saturation

作者：Angst Ueli^*; Elsener Bernhard; Myrdal Roar; Vennesland Oystein

来源：Electrochimica Acta, 2010, 55(28): 8545-8555.

DOI：10.1016/j.electacta.2010.07.085

• Diffusion potential
• Membrane potential
• Permselective behaviour
• Cement based material
• Ion selective electrode

Diffusion potentials (membrane potentials) were measured in mortar in a moisture state below saw ration for the first time In contrast to conventional diffusion cell setups the experimental approach was based on embedded ion selective electrodes A numerical model with coupled Nernst-Planck equations for the most abundant species in the pore solution allowed simulating ion transport processes and the correspondingly arising diffusion potentials It was found that Portland cement mortar with a water/cement ratio of 0 6 does not exhibit any significant permselective behaviour - even not in an unsaturated state determined by self-desiccation Apparently the stable radius of water-filled capillaries is still large enough to allow ionic transport through those fractions of pore solution that are unaffected by double layer effects In addition the relative importance of liquid junction potentials at the reference elect

• 出版日期2010-12-1