Determination of particle density using water and gas pycnometry

Particle density is often measured to allow assessment of the volume of voids in a material. Density is generally assessed using water displacement in capillary flasks. However, full saturation of microporous materials can be difficult and time consuming (Morris & Williams, 1996). Semi-automated gas pycnometers are becoming more prevalent, and enable the density of dry materials to be assessed in under an hour. This paper presents a comparison of the two testing methods carried out on a range of materials. It shows that cation exchange capacity (and related water of hydration) can significantly affect values of particle density...