Analysis of hydration processes in porous materials using terahertz pulsed imaging

Solvent penetration in porous solids is a very important property that limits the performance of a range of materials in industrial applications. Here we show how terahertz pulsed imaging (TPI) can be used to investigate the uptake of water into materials relevant to the pharmaceutical sciences and catalysis by using depth resolved tracking of the water/solid interface over time upon exposure of the porous solid to water. TPI is an exciting characterisation technique to study such solvent transport processes due to its millisecond time resolution and the transparency of ceramics and polymers to terahertz radiation. These properties make TPI unique to investigate fast processes compared to other measurement modalities.