Food packaging, as a main process to maintain the quality of food products from the time of manufacture to consumption, plays an essential role in the modern food industry. New food packaging technologies are being developed with natural ingredients (such as polysaccharides) that are formulated to use synthetic/chemical UV protection agents, such as antioxidant and antioxidants, to meet consumer expectations for healthy food. In addition, biodegradable packaging materials are attracting a lot of attention in the face of growing environmental concerns about plastic pollution. The aim of this research is to prepare agar aerogel film containing nanoparticles of graphene quantum dots, which has anti-ultraviolet radiation and antioxidant properties, and at the same time, it is biodegradable and increases the shelf life of food and reduce plastic waste. Chlorine doped graphene quantum dots (Cl-GQDS) were synthesized by hydrothermal method and fructose precursors as carbon source and hydrochloric acid as chlorine source. High resolution transmission electron microscope (HR-TEM) images show that graphene quantum dots are spherical and single, their average diameter is 12.42±1.1 nm, and the lattice parameter in these nanoparticles is 0.24 nm. The XRD results showed that the distance between the graphene sheets was 0.402 nm. The presence of chlorine atom in the results of Raman and Fourier transform infrared spectroscopy (FTIR) analysis confirmed the effective doping of chlorine in the structure of synthesized graphene quantum dots. Then Agar aerogel films containing 0, 1, 5, 10, and 20 percent by volume of Cl-GQD solution were synthesized by freeze drying method. The results of FTIR and XRD analysis confirmed the presence of Cl-GQD solution in the structure of aerogel films. The morphology of the films was examined by scanning electron microscope (SEM). The eva‎luation of the holes inside the films was done with the BET test and it was determined that with the increase in the percentage of graphene solution in the film structure, the number of holes and porosities in the structure increases and the mechanical properties of the film decrease drastically. The anti-ultraviolet properties of agar aerogel films were measured with a spectrophotometer. eva‎luation of the antibacterial activity of graphene quantum dots doped with chlorine was done by MIC and MBC tests. It was found that because the graphene solution was not exposed to blue light, it has no phototoxicity and does not have the ability to increase intramolecular ROS. As a result, its antibacterial ability is very low compared to Ampicillin antibiotic (higher than 1000 micrograms/ml). Their antioxidant properties were eva‎luated by DPPH free radical scavenging method. The results showed that Cl-GQD in the structure of agar aerogel films increased the anti-ultraviolet radiation and antioxidant properties of the films. Finally, agar aerogel film containing 5% by volume of Cl-GQD solution was identified as the optimal film. This film had better mechanical properties. It also had antioxidant properties of nearly 20% and absorption of ultraviolet rays above 95%. Therefore, it is more suitable for use in food packaging.

هاجر شكرچي زاده

صبيحه سليمانيان زاد، مهرنوش جعفري