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

Abstract

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.