Research Interests
Crystallisation in Confinement
Crystallisation in the real world often happens in a confined space rather than in a bulk solution. For instance, the crystallisation of biominerals, the development of nanomaterials and the formation of weathering products in porous media all occur under confinement. The thermodynamics and kinetics of the system are dramatically altered in these settings. Due to these differences I am interested in the effects of confinement for a variety of crystalline systems and for multiple topics: (i) crystallisation pathway, (ii) polymorph selection, (iii) crystal morphology, and (iv) surface chemistry. The aim is to be able to understand these effects in order to control crystallisation.
[1] Meldrum & O'Shaughnessy (2020);
The Structure of Glass
Amorphous materials are incredibly important in a range of geological environments ranging from carbonates and silicates produced through biologically activity to volcanic glasses. Their technological applications are also numerous; from bioactive glasses, nuclear waste containment, photovoltaic cells, etc. In order to understand and eventually design materials with given properties the characterisation of their microstructure is of fundamental importance. Due to these materials' lack of periodicity typical characterisation techniques, such as X-ray diffraction, are rendered useless. Thus, a variety of spectroscopic techniques must be used to attempt to quantify the chemical speciation and structure of these complex materials. My interests lie mainly in the characterisation of vitreous samples using a combination of Raman and X-ray spectroscopic techniques to elucidate these structures.
[1] Moulton et al. (2016); [2] Nesbitt et al. (2017); [3] O'Shaughnessy et al. (2017); [4] O'Shaughnessy et al. (2018a); [5] Bancroft et al. (2018); [6] O'Shaughnessy et al. (2018b); [7] Nesbitt et al. (2019); [8] O'Shaughnessy et al. (2020)
High-Temperature Foams
Volcanic eruptions are typically governed by the viscosity of the magma, which is a mixture of melt, crystals, and gas. At the top of the volcanic conduit magmas with very high proportions of gas can exist and this is the case in many open-conduit, basaltic volcanoes. Places such as, Kilauea on the Big Island of Hawaii or Stromboli in the Aeolian Islands of Italy commonly have very high gas fraction magmas which can be interpreted as foams. The physical properties, porosity and permeability, of these foams play an important role in determining the type of eruptive activity. I am interested in using X-ray tomographic microscopy to quantify these properties in-situ.
[1] Baker et al. (2012); [2] O'Shaughnessy et al. (2014); [3] Baker et al. (2019)