President's Showcase
Semhare Tekle she/her/herself
Supervising Professor: Oliver Steinbock
Semhare Tekle is a senior student at Florida State University majoring in Biochemistry, originally from Jacksonville, Florida. As the middle child of four in an immigrant household, Semhare has a deep connection to her hometown, especially the St. John's River. For the past, year, she has worked in a physical chemistry laboratory under the guidance of Dr. Oliver Steinbock, focusing on understanding bubble formation in chemical gardens. She looks forward to pursuing a PhD abroad.
Abstract
Chemical gardens are fascinating self-organized structures that emerge when a metal salt reacts with a silica-based alkaline solution. Although the process is straightforward, the details of how these structures form and the principles behind their shape selection are not fully understood. These centimeter-scale formations resemble hydrothermal or volcanic vents, which are important in studying the origins of life on Earth.
During the chemical garden formation, not only do tube-like structures develop, but small gas bubbles are also produced. These bubbles, which may contain CO₂, form as the dissolution of salt decreases the local pH, reducing CO₂ solubility. This research investigates the chemical composition of these bubbles and the mechanisms driving their formation. The study involves capturing and analyzing videos of the chemical garden growth and using MATLAB to quantify the bubbles' number and volume. To test the hypothesis that CO₂ is a major component, varying concentrations of sodium carbonate are added to degassed silicate solutions, shedding light on the gas composition and its implications for early Earth conditions.
Presentation Materials