Light Downshifting ZnO-EVA Nanocomposite Greenhouse Films and Their Influence on Photosynthetic Green Algae Growth

Greenhouses are self-contained ecosystems that can be optimized to create favorable microclimates for crop growth and productivity. Their productivity can be improved by introducing functionality to the polymer films using nanotechnology. In this work, ZnO quantum dots (QDs) were capped with vinyltrimethoxysilane (VTS) to help stabilize the QDs within the polymer matrix, improve material properties, and enhance light downshifting properties for enhanced plant photosynthesis. The VTS-ZnO QDs were solution-mixed with an ethylene vinyl acetate copolymer, resulting in a transparent nanocomposite that downshifted UV light into visible blue light and also improved the thermal and hydrophobic properties. Chlamydomonas reinhardtii was used as a model photosynthetic system to study how the QD-tuned light can enhance growth rates. Growth rates were increased up to 4.7% when cultured behind a ZnO nanocomposite film. Our results show that the VTS-ZnO nanocomposite films increase the available light within a greenhouse, demonstrating enhanced growth rates. Testing these effects on agricultural crops will be an important step for future work.