Colloids are promising materials for a wide range of applications such as selective separations, catalytic processing, and enhanced chemical activity. However, these applications are limited without proper knowledge of colloidal bulk properties. Therefore, the characterization of colloids is important for applications in industry. This work reports the use of the Nova 4200ee instrument to measure the surface area of calcium carbonate (CaCO3) nanoparticles using the Brunauer-Emmett-Teller (BET) method with nitrogen gas as the adsorbate. We investigate the effect of different drying techniques on the measured surface area of CaCO3 nanoparticles. Results reveal a higher surface area for samples that were either freeze-dried, heat-dried, or both, and a much lower surface area was observed for samples that were diluted before drying. We also characterize silica particles using Small Angle X-ray Scattering (SAXS) and employing Silver Behenate (AgBoH) as our scattering vector (q) calibrant. To probe short-ranged inter-particle interactions, we make use of the Ultra Small Angle X-ray Scattering (USAXS).. The information revealed by BET and X-ray scattering will be useful for manufacturing materials that will be of great use in the nanotechnology field.
Advisor: Michael Harris, Chemical Engineering, Purdue University, West Lafayette, IN
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