Photo-degradation of electrospun composite mats based on poly(D,L-lactide) submicron fibers and zinc oxide nanoparticles

Electrospun polymeric mats constitute promising materials in the environmental area as filtering media. However, mats are typically subjected to UV irradiation throughout their use; therefore, investigation related to additives useful for mitigating their photo-degradation is necessary. In this regard, this paper addresses the long-term photo-degradation study of submicron poly (D,L-lactide) (PLA) fibers with embedded or sprayed ZnO nanoparticles which were engineered by means of electro-hydrodynamic techniques, namely electrospinning or electrospinning/electrospraying tandem processes. An extensive physico-chemical characterization of the corresponding PLA/ZnO composite fibers was performed before and after artificial UV aging by ATR-FTIR, SEC, and SEM. It was demonstrated that the ZnO concentration and the electro-hydrodynamic technique utilized had a significant effect on the UV shielding related to the nanoparticles distribution/dispersion achieved. Furthermore, a morphological development as a function of UV aging time was proposed, thus suggesting an optimal life cycle of the PLA/ZnO composite fibers, which could be extremely useful for future applications as UV-activated filtering media. (C) 2018 Elsevier Ltd. All rights reserved.