2021 Virtual Undergraduate Research Symposium
2021 Virtual Undergraduate Research Symposium
Cold Sintering-Teaching Old Rocks New Tricks
Cold Sintering-Teaching Old Rocks New Tricks
PROJECT NUMBER: 69 | AUTHORS: Alexander Hopkins, Metallurgical and Materials Engineering and Annaliese Dunn, Geology and Geological Engineering
MENTORS: Geoff Brennecka, Metallurgical and Materials Engineering and Alexis Sitchler, Geology and Geological Engineering
ABSTRACT
Understanding the ability of calcium carbonate to precipitate into either calcite or aragonite has important implications for geological processes and ceramic science. The aim of this project is to use materials science and geochemical techniques to predict the structure and shape of calcium carbonate precipitates. This could be applied as a technique in the novel field of cold sintering. Calcium carbonate was dissolved in water and then left to precipitate with three substrates: Al2O3, TiO2, SiO2, and with differing pH to see what effect those factors had on the crystallization process. These were chosen given the importance of pH on the solubility of calcium carbonate [1], and because the substrates have varying surface chemistries and isoelectric points. The results of our research were the identification of calcite rhombs in the titania substrate trial, and to a lesser extent in the alumina substrate trial. Also, increasing the pH led to finer average grain size.
PRESENTATION
AUTHOR BIOGRAPHY
Alex is a sophomore in the Metallurgy and Materials Engineering department. His research combines the fields of geology and materials engineering to understand calcium carbonate nucleation. He would like to continue this research in the future by improving the ability to control crystal size.
Annaliese Dunn is a senior in the Geological Engineering Department. Her research combines the fields of geology and materials engineering to understand calcium carbonate nucleation. She is excited to graduate and take the experience she gained from research into the tunneling industry.
Does increasing or decreasing the pH of the solution affect the geometry of the substrates? What is the main control that forms the rhomb geometries? Have you tested calcium carbonates such as dolomites?
We haven’t tested with any other carbonates, although that is something we are considering looking into in the future. pH did have some impact on the substrate pellets. Calcite is a hexagonal crystal, so it is likely to form rhombs. Thank you for your interest in the project.
Very interesting project, good job! I like the name of your project as well, very clever!
Great presentation and research project! I really appreciate the depth that you went into on each of your trials and your results. What do you hope that this research can add in the greater scheme of materials science and research?
We are hoping to gain a better understanding of how to precipitate ceramics, so that we can try to use it as a novel method of sintering
Great job!
Out of curiosity, what are the size of these crystals (for all subtracts and pH tested).
the larger crystals we identified were on the order of 0.1 mm in size.