Effect of silver nanoparticles and cellulose nanocrystals on electrospun poly(lactic) acid mats: morphology, thermal properties and mechanical behavior.

The fabrication of ternary fibrous mats based on poly(lactic) acid (PLA), cellulose nanocrystals (CNCs, both pristine (p-CNCs) and modified with a commercial surfactant (s-CNCs)) and silver (Ag) nanoparticles by electrospinning is reported. Amounts of 1 and 5 wt.% were selected for Ag and CNCs, respectively. Neat PLA and binary PLA/Ag, PLA/p-CNCs and PLA/s-CNCs were produced as references. The CNCs and Ag influence on the microstructural, thermal and mechanical properties was investigated. The Ag and/or p-CNCs addition did not remarkably affect fiber morphology and average size dimension (between (468 ± 111) and (551 ± 122)nm), whereas the s-CNCs presence led to the deposition of a honeycomb-like network on a underneath layer of randomly oriented fibers. The efficiency of the surfactant use in promoting the CNC dispersion was demonstrated. A slight enhancement (e.g. around 25%, in terms of strength) of the mechanical properties of p-CNCs loaded fibers, particularly for PLA/Ag/p-CNCs, was revealed, whereas mats with s-CNCs showed a decrement (e.g. around 35-45%, in terms of strength), mainly imputable to the delamination between the upper honeycomb-like layer and the lower conventional fibrous mat.