Preparation and characterization of poly(l-lactic acid)/TiO2 nanoparticle nanocomposite films with high transparency and efficient photodegradability

Poly(l-lactic acid)-TiO2 nanoparticle nanocomposite films were prepared by incorporating surface modified TiO2 nanoparticles into polymer matrices. In the process of preparing the nanocomposite films, severe aggregation of TiO2 nanoparticles could be reduced by surface modification by using carboxylic acid and long-chain alkyl amine. As a result, the nanocomposite films with high transparency, similar to pure PLA films, were obtained without depending on the amount of added TiO2 nanoparticles. A TEM micrograph of the nanocomposite films suggests that the TiO2 nanoparticles of 3-6 nm in diameter were uniformly dispersed in polymer matrices. Photodegradation of PLA-TiO2 nanoparticle nanocomposite films was also investigated. The results showed that nanocomposite films could be efficiently photodegraded by UV irradiation in comparison with pure PLA.