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Poly(butylene adipate-co-terephthalate) (PBAT) is a biodegradable aliphatic-aromatic copolyester. In this paper, we report the radio induction of photoluminescence (PL) properties in PBAT, after exposure to high doses of gamma radiation. After the previous high-energy irradiation, the material shows the highest photo-stimulated luminescence emission when excited with a light-emitting diode (LED) source at wavelengths ranging from 370 to 405 nm. The PL intensities obtained after excitation with an LED source of 385 nm are proportional to gamma doses ranging from 100 to 1000 kGy in the preirradiation process. FTIR data revealed that the gamma-induced aromatic amine groups may be responsible for the appearance of the postirradiation PL character in PBAT samples. The results indicate that PBAT has great potential for applications in in vitro imaging of human cancer, bioimaging devices, and radiation dosimetry. [ABSTRACT FROM AUTHOR]

In this paper we study the photo-oxidation phenomenon in the structure of a PPV derivative, the poly[(2-methoxy-5-hexyloxy)- p -phenylenevinylene] - (MH-PPV), using ellipsometry and infrared spectroscopy techniques. Ellipsometric measurements were carried out in MH-PPV films previously exposed to light irradiation in air. It was observed a variation of both real and imaginary components of the refractive index. These variations are related with the replacement of the vinyl C=C bounds by the carbonyl C=O bounds, as confirmed by the infrared absorption measurements. [ABSTRACT FROM AUTHOR]