Beamtime at the Small Angle X-ray Scattering Beamline (I22) at Diamond Light Source funded through Diamond Light Source.
Abstract of research proposal:
Calcium carbonate phases (CaCO3) are common biominerals formed by oceanic
organisms. They are key components of the modern and ancient global carbon cycle, and a major sink for atmospheric CO2. Crystalline CaCO3 biominerals often form via metastable precursors and their reaction pathways are controlled by saturation state, temperature and pH. However, common seawater ions (i.e., Mg2+, SO42- and PO43-) also play a crucial role in these reactions but their effects have so far not been quantified. This is primarily because the crystallization reactions are rapid (seconds) and until recently in situ and fast monitoring techniques were lacking. The capabilities of station I22 have now changed that landscape, and we aim to use the second to sub-second data acquisition capabilities on I22 to follow in situ the formation of CaCO3 polymorphs via ACC as a function of Mg2+, SO42- and PO43- content.