Monolithic polymers are essentially a single piece of continuous porous material which represent a new generation of stationary phases for chromatography, offering significant benefits over currently used materials.In terms of the surface modification of these stationary phases, one of the most recent approaches to incorporate functionality is the incorporation of nanoparticles based on the favourable surface area-to-volume ratio of these materials. However, there is a lack of understanding of the effect the nanoparticles have on the morphology of the porous materials and about where the nanostructures are located within the polymer structure.Accurate characterisation of where these nanoparticles are incorporated into these materials is essential for future developments in this field.
STXM is a synchrotron-based microscopy technique which gives information about the spatial distribution of chemical components at sub-50 nm spatial resolution based on near edge X-ray absorption fine structure spectral (NEXAFS) contrast. Therefore, STXM would allow us to perform chemical mapping of the polymers containing nanostructures and identify the distribution of the nanoparticles within the polymeric scaffold, which is extremely difficult to achieve with other commonly used techniques for the characterisation of monolithic columns such as SEM and TEM.
In this work, we present the characterisation of methacrylate-based monoliths containing nanoparticles bearing different functionality by STXM. The results obtained show the potential use of this technique as a unique tool for the characterisation of stationary phases.