PhD Defence – 14:30 and following 

Friday, 1 June 2018

Auditorium 2, Universitetsparken 5, 2100 Copenhagen Ø

  Applications of high resolution X-ray techniques in studying chalk and calcite: Mineral-organic compound interface behaviour and microstructure evolution

 Sepideh Sadat Hakim, cand. scient. 

      NanoGeoScience Group, Nano-Science Center, Department of Chemistry, University of Copenhagen

Abstract

Chalk is a dominant rock type in Denmark. It is important  geologically and in industry, with many economic aspects, such as oil recovery, drinking water supply and CO₂ sequestration. The research presented in this thesis focuses on chalk and calcite, its primary component. Interactions of calcite surfaces with simple organic compounds were investigated as a model for chalk. X-ray reflectivity and surface modelling were used to explore the structure of adsorbed organic layers on calcite surfaces. In the second part of this research, the influence of CO₂ on the microstructure of chalk was investigated by using 3D imaging X-ray microtomography. The results from greyscale analysis of the tomography data from in situ experiments were used to study the dissolution patterns and microstructural evolution of porous media, i.e. porosity and surface area, in chalk.