Date of Award
Master of Science
Dr. Sean R. Shieh
Carbon dioxide (CO2) is one of the greenhouse gases in the atmosphere and possibly it can be found the Earth in a solid state form. The strength and elasticity study of carbon dioxide (CO2) under high pressures is important to understand the rheological behavior of CO2 that may be relevant to the CO2 storage issue within the Earth and also explaining the evolution of terrestrial planets. Quantitative measurements of the strength of C02were achieved in a diamond anvil cell using angle dispersive x-ray diffraction (AXDX). The strength of CChis determined using three different methods. At first the shear stress is calculated using the pressure gradient of the CO2 under stress using a ruby florescence method. Secondly the peak shifts in radial direction using ADXD method is used to analyze calculate the differential stress and at last the peak broadening in axial direction in ADXD method is used to calculate the deviatoric strain. In addition the equation of state and the second order cubic elastic constant have been calculated. The shear stress of CO2 was measured by using pressure gradient and reaches a value of 1.13 GPa at pressure 48. The ratio of the main differential stress to the aggregate shear modules are 3.3-8% for pressures from 4-37 GPa. The differential stress has is less than 0.5 GPa at pressure below 12GPa and it rise quickly up to 2.4GP at ~37GPa. The deviatoric strain of the sample yielded a value of 0.106-0.521 GPa.
Kaci, Linda, "Strength and Elasticity Study of Carbon Dioxide (CO2) under High Pressure" (2011). Digitized Theses. 3529.