Effects of Amino Acids on Iron-Silicate Chemical Garden Precipitation

Understanding the structure and behavior of chemical gardens is of interest for materials science, for understanding organic-mineral interactions, and for simulating geological mineral structures in hydrothermal systems on Earth and other worlds. Herein, we explored the effects of amino acids on inorganic chemical garden precipitate systems of iron chloride and sodium silicate to determine if/how the addition of organics can affect self-assembling morphologies or crystal growth. Amino acids affect chemical garden growth and morphology at the macro-scale and at the nanoscale. In this reaction system, the concentration of amino acid had a greater impact than the amino acid side chain, and increasing concentrations of organics caused structures to have smoother exteriors as amino acids accumulated on the outside surface. These results provide an example of how organic compounds can become incorporated into and influence the growth of inorganic self-organizing precipitates in far-from-equilibrium systems. Additionally, sample handing methods were developed to successfully image these delicate structures.