Effects of physico-chemical interfacial equilibrium on pore shape in solid

The shape of a pore, resulting from a bubble entrapped by a solidification front, for different Henry's law constants at the cap is predicted in this work. Henry's law, indicating an interfacial physico-chemical equilibrium, is essentially required to relate solute concentration in liquid at the cap by solute gas pressure in the pore. Pore formation and its shape in solid influence contemporary issues of biology, engineering, foods, geophysics and climate change, etc. This work applies a previous model accounting for mass and momentum transport of solute across a self-consistently determined shape of the bubble cap subject to different cases characterized by different directions and magnitude of solute transport across the cap. Case 1 is referred to solute transport from the pore across cap to surrounding liquid in the early stage. Cases 2a and 2b, corresponding to low and high Henry's law constants, respectively, indicate opposite directions of species transport across the cap. An increase in Henry's law constant decreases pore radius and time for entrapment in Case 1. The pore cannot be entrapped as a pore in solid in Cases 2. The predicted pore shape in solid agrees with experimental data. Understanding, prediction and control of the growth of the pore shape have therefore been obtained. (C) 2017 Elsevier Ltd. All rights reserved.