Investigation of the radiation induced photoluminescence features in starch-based biodegradable polymers

The present work presents a study on the production and photoluminescent (PL) characterization of starch-based biodegradable polymer films, after exposure to ionizing radiation. Research in the area of biodegradable materials is increasing, which makes possible to meet the demand for new applications in the medical, agricultural and industrial areas. Through these biodegradable materials, it is possible to replace or reduce the consumption of petroleum derived materials from renewable sources, thus contributing to the environment and sustainable economy. Among the biodegradable materials, there are the biopolymer films made from potato starch, a low cost material. In this context, films made from potato starch, which initially show no photoluminescent properties, were exposed to a high energy radiation beam. After irradiation, the films were photo-stimulated with a 405 nm LED, revealing a photoluminescent emission peak centered at 535 nm. The structural characterization were performed by UV-Vis and FTIR spectrophotometry, Differential Scanning Calorimetry and X-ray Diffractometry. Radiation dosimetry features were investigated by PL emission spectroscopy. The irradiations were performed in the Gamma Irradiation Laboratory of the CDTN (Co-60 source, 60,000 Ci) for doses ranging from 1 to 2,000 kGy. The results indicated an increase of the PL intensity for increased gamma doses, revealing an unambiguous relationship between PL x Dose. The starch-based biodegradable films are good candidates for application in high gamma dosimetry and also in bio-imaging devices. (author). (author)