A transparent and waterproof cellulose composite film with carbon quantum dots: A greener agricultural film capable of light management

Biodegradable agriculture films with the function of light conversion to better match the spectrum of plant photosynthesis are critical for achieving sustainable development and boosting plant production. In this work, transparent light conversion cellulose composite films were prepared by incorporating blue and red emitting carbon dots (B&R-CDs) into a regenerated cellulose (RC) film, followed by covering with a silicone acrylic emulsion (SAE) layer to enhance water resistance. SEM observations showed that the surface of the cellulose composite film was smooth. The fabricated SAE/B&R-CDs/RC film featured a high average transmittance (89.7 %) in the visible region. Its photosynthetic photon flux density (PPFD) was 4.7 % higher than that of the film without CDs. The cellulose composite film exhibited a tunable water vapor transmission rate (WVTR) by changing the thickness of the SAE layer. The cellulose composite film possessed a high tensile strength of 60 MPa and an elongation at break of 13.6 %. In particular, despite the presence of the SAE, the SAE/B&R-CDs/RC film fully degraded after 112 days of soil burial. This study opens up a novel avenue for the development of biodegradable and light-conversion functional agricultural films.