Antimicrobial bionanocomposites of poly(lactic acid)/ZnO deposited halloysite nanotubes for potential food packaging applications

Abstract

In this study, nanocomposites of polylactic acid (PLA) with ZnO deposited halloysite nanotubes (HNT) (ZnO@HNT) were synthesized by using ultrasound assisted solvent casting method. The synthesized PLA/ZnO@HNT films were characterized for physical, thermal, mechanical, UV-shielding, barrier properties and antimicrobial activity for food packaging applications. The nanocomposite film PZH2 (consisting 2 wt% ZnO@HNT) showed the best properties with percentage increments over PLA as: surface hydrophobicity (16.5%), water vapor barrier (51.1%), flexibility (79.3%), tensile strength (38.9%), elastic modulus (507.1%), UV barrier property (95.3%), antimicrobial activity (R> 99%). Moreover, a packaging test was performed on cut apples for 6 days storage period to evaluate the potential efficacy of nanocomposite films for food packaging applications. The PZH2 films showed considerably improved results as follows: weight loss = 4.17%; total soluble solids = 10.9°Brix; firmness = 2.4 N; and pH = 4.0. The results have demonstrated efficiency of PLA/ZnO@HNT nanocomposite films as potential food packaging material. • Synthesis of PLA/ZnO@HNT composite films using ultrasound-assisted solvent casting • ZnO@HNT improves mechanical, UV-shielding, barrier properties of PLA films • Excellent antimicrobial properties of PLA/ZnO@HNT films for food packaging • Practical packaging test performed on cut apples stored at room temperature for 6 days • Best properties of PZH2 films: weight loss = 4.17%; TSS = 10.9°Brix; firmness = 2.4 N