PhD defence: Ivan S. Pasarin

Title: "Chalk and calcite characterization with X-ray methods: Submicrometer morphology and interaction with simple organic molecules"

Abstract
Chalk is a versatile material. Its uses range from teaching tool to cement production,from controlling the acidity of soils and industrial gas emissions to plastic and paper whitening. Chalk also forms aquifers that supply drinking water to southern England and Sweden, northern France and most of Denmark. This porous rock is present all around the world. In some places, such as the North Sea and Texas, chalk forms oil reservoirs. As part of the Nano-Chalk Venture, this Ph. D. thesis contributes in the development of new techniques to enhance oil recovery from chalk reservoirs, in particular, by focusing on the capabilities
of several X-ray techniques. First, wide and small angle X-ray scattering allowed characterisation of the submicrometer morphology of chalk, which is critical for understanding oil and water ows. Second, X-ray reectivity and X-ray photoelectron spectroscopy provided new insight on the calcite- ethanol interface. Calcite is the main component of chalk, and ethanol, the simplest chain molecule containing a hydroxy group, which makes the calcite-ethanol interface an excellent model to start understanding the chalk-hydrocarbon interaction.The versatility of X-rays and the fundamental nature of the questions addressed in this thesis opened the scope of the developed methods and gained insight well beyond their initial focus on enhancing oil recovery, for example, the method developed for characterising chalk submicrometer morphology is applicable on many other porous materials, while a better understanding of the basic interaction between organic molecules and minerals at the molecular level can unveil the mechanisms driving biomineralisation processes.