Photodegradation of LDPE/modified starch blends 80/20 m/m has been examined by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and X ray diffraction (DRX) before and after exposure to ultraviolet radiation (UV). Samples were exposed to UV in the laboratory for periods of 6, 24, 48 and 60 hours. The main alteration in the polymeric material after exposure to the radiation was a decrease in the mechanical properties, tensile strength and elongation. There were also changes in the chemical structure of the blend with an increase in the carbonyl and vinyl indices, 65.58 and 53.29%, respectively. The analysis of the blend crystallinity pointed to the formation of a new crystalline symmetry that did not exist before the irradiation.

The TiO2/UV photocatalytic reactor was investigated as an alternative system to inactivate airborne microorganisms. The experiments performed in the absence of the catalyst showed that direct photolysis was not efficient to destruct microorganisms, with only 30% of inactivation. Similar inactivation percentage was obtained using TiO2 in absence of UV radiation. The destruction of microorganisms present in a contaminated indoor atmosphere, using the combination of TiO2/UV was very efficient, reaching more than 98% of destruction.