Modelling pore-level properties of porous materials
Pore-Cor is a 1.2 Mbyte Fortran 77 software package, which uses information from mercury porosimetry curves, supported by image-analysed electron micrographs, to generate a three-dimensional representational model of the pore-space within a porous material. As a result of this project, a much-improved version has been produced. The mercury intrusion curves for the simulated structures now converge automatically onto the experimental curves, so reducing the simulation time from several days to less than an hour. A further time economy has been provided by the incorporation of an improved permeability routine, reducing the calculation time from 10 minutes to 30 seconds. Modifications have allowed non-homogeneous structures to be modelled, in simulation of real samples of banded, vuggy and clay-included sandstones. Porosimetry measurements have been made for Fontainebleau sandstone into which small amounts of illite, a simulated clay deposit, had been introduced by hydrothermal crystallisation. Despite having no effect on porosity, the effects on simulated permeability could be successfully assessed. The causes of hysteresis, i.e. the trapping of a non-wetting fluid in a porous medium, were also investigated. The need for higher quality experimental data to feed into the Pore-Cor software has led to improved measurement and analysis methods for the porosimetry. A new spreadsheet-based iterative programme, named Pore-Comp. provides a unique method of measuring the compressibility (or bulk modulus) of the solid phase of a porous medium, and this has been used to examine the effects of silicate micro-crystallinity and latex binders on the compressibility of paper-coating formulations. Using the cryo-stage of the electron microscope, the retention of mercury in some paper coating formulations has been investigated further.