Application and Characterization of a Novel Biocomposite Derived from Invasive Didymosphenia geminata

Didymosphenia geminata is a species of diatom, a clade of algae so abundant that it is responsible for 20% of photosynthetic activity worldwide. D. geminata has also been classified as an invasive species on multiple continents due to their extracellular stalks creating thick mats, which can destroy benthic ecosystems in rivers, lakes, and streams. This research outlines methodology and preliminary applications of a biocomposite derived from the extracellular stalks of D. geminata. Biocomposite alternatives are becoming more necessary due to the rampant carbon emissions generated by materials in the construction industry. We specifically focus on creating an alternative to expanded polystyrene packing materials, as well as fiberglass and polystyrene insulators. We propose a fast, single-step chemical treatment process that allows the bulk composite to be molded depending on its application, and find results comparable to our target materials. Notably, the bulk material can be recycled between mechanical and thermal applications without loss of strength or insulating capabilities, provided the thermal breakdown point of 300°C is not reached. For another application of our composite, we investigate the use of powdered D. geminata material in the adsorption of small-scale oil spills. We find that the cleaned, unaltered material acts as an average adsorber, but has the ability to be enhanced through the binding of silica nanoparticles. Future avenues of work involve improving the mechanical strength of the material, or increasing its porosity to lower thermal conductivity. We also outline potential processes to make the nanoparticle binding process more environmentally friendly, with optimized chemical usage and less harmful byproducts.