Merged with duplicate record 10026.1/839 on 27.02.2017 by CS (TIS)The aim of this project was to enhance the current state of knowledge of the void structure
of paper, and pigments used to coat paper. The porosities and pore size distributions of
consolidated pigments were measured using mercury porosimetry. Prior to this work,
mercury porosimetry was rarely used in this field due to problems associated with the
conventional interpretation of mercury porosimetry data. These problems were examined
and two limitations of mercury porosimetry were addressed. Firstly, the shrinkage of
compressible samples causes an apparent increase in void volume and secondly, large void
spaces shielded by smaller ones are not intruded until anomalously high applied pressures of
mercury are reached. The first limitation was overcome by means of a new correction
procedure which, uniquely, also allows the measurement of the bulk modulus of the
continuous solid phase of a porous sample. Shielding effects have been taken into account by
means of a software package known as Pore-Cor, which generates a three dimensional
structure which has both a mercury intrusion curve and porosity in close agreement with
experiment. It has also been possible to calculate the permeabilities and tortuosity of the
simulated structure and this provides realistic and useful values, which may not be measured
experimentally.
Mercury porosimetry and a range of specialised absorption techniques, including liquid
porosimetry, were used to characterise the porous structures of a highly filled paper which
had been calendered using a range of different conditions. A unique feature of this work is
that for the first time it has been shown that two porosimetric techniques which measure
overlapping pore size distributions may be combined to give a better indication of the total
pore size distribution.ECC International plc