Binary and ternary poly (L-lactide) (PLLA) based nanocomposites, containing nanolignin (1% wt.) and different metal oxide nanoparticles (0.5% wt., Ag2O, TiO2, WO3, Fe2O3 and ZnFe2O4) were realized by solvent casting and their morphological, thermal, surface, optical, antioxidant and antimicrobial characterization was performed. The presence of metal oxide nanoparticles at the selected weight concentration affects the surface microstructure of the PLLA polymer and this outcome is particle-type dependent, accordingly to the shape, morphology and chemical properties of the selected NPs. Analogously, wettability of PLLA based nanocomposites was slightly modified by the presence of hydrophobic lignin nanoparticles and different shaped metal oxides. Results of DSC and XRD tests confirmed that nanoparticles addition confined the mobility of the amorphous phase, increasing at the same time the formation of more numerous but less perfect PLLA crystals. Interestingly, antioxidant activity was also obtained in ternary based nanocomposites, where a synergic effect of lignin and metal oxide nanoparticles was obtained. Antibacterial tests showed manifest activity of TiO2 and Ag2O nanoparticles containing PLLA films, and the time dependence was more evident for S.aureus than for E.coli. Lignin nanoparticles are able to provide protection against UV light while still allowing visible light to pass and even surpassing the UV-protection capacity provided by many inorganic nanoparticles. This make them an attractive renewable additive for the realization of PLLA/metal oxides nanocomposites for the fields of food, drug packaging and biomedical industry, where antibacterial and antioxidant properties are required.
Synergic Effect of Nanolignin and Metal Oxide Nanoparticles into Poly (L-lactide) Bionanocomposites: Material Properties, Antioxidant Activity and Antibacterial Performance
Armentano, Ilaria;Torre, Luigi;Puglia, Debora
2020
Abstract
Binary and ternary poly (L-lactide) (PLLA) based nanocomposites, containing nanolignin (1% wt.) and different metal oxide nanoparticles (0.5% wt., Ag2O, TiO2, WO3, Fe2O3 and ZnFe2O4) were realized by solvent casting and their morphological, thermal, surface, optical, antioxidant and antimicrobial characterization was performed. The presence of metal oxide nanoparticles at the selected weight concentration affects the surface microstructure of the PLLA polymer and this outcome is particle-type dependent, accordingly to the shape, morphology and chemical properties of the selected NPs. Analogously, wettability of PLLA based nanocomposites was slightly modified by the presence of hydrophobic lignin nanoparticles and different shaped metal oxides. Results of DSC and XRD tests confirmed that nanoparticles addition confined the mobility of the amorphous phase, increasing at the same time the formation of more numerous but less perfect PLLA crystals. Interestingly, antioxidant activity was also obtained in ternary based nanocomposites, where a synergic effect of lignin and metal oxide nanoparticles was obtained. Antibacterial tests showed manifest activity of TiO2 and Ag2O nanoparticles containing PLLA films, and the time dependence was more evident for S.aureus than for E.coli. Lignin nanoparticles are able to provide protection against UV light while still allowing visible light to pass and even surpassing the UV-protection capacity provided by many inorganic nanoparticles. This make them an attractive renewable additive for the realization of PLLA/metal oxides nanocomposites for the fields of food, drug packaging and biomedical industry, where antibacterial and antioxidant properties are required.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
