Advancing sustainable technologies: plasma-engineered bioplastics with silver nanoparticle integration

The advancement of sustainable packaging technologies is crucial for environmental conservation and enhancing food shelf life. We advance sustainable packaging by developing cassava starch sheets functionalized with silver nanoparticles (AgNPs) via plasma-deposited 2-methyl-2-oxazoline thin film. This innovative method requires less precursors and generates no liquid waste, presenting a significant leap in eco-friendly packaging solutions. Uniquely, it deviates from traditional nanoparticle incorporation methods by emphasising surface functionalization over bulk integration, leveraging plasma polymerization for environmentally friendly and efficient AgNP immobilisation. This surface-centric approach offers distinct advantages in active packaging by enhancing the initial antimicrobial interaction at the packaging's surface. Surface morphology, characterised by SEM–EDX, and chemical composition, verified by XPS, indicated successful AgNP immobilisation after 5 and 25 h, albeit with some aggregation at prolonged immobilisation time. UV–Vis spectroscopy results confirmed the successful immobilisation of AgNPs and suggested enhanced light barrier properties of the treated sheets. AFM measurements revealed alterations in surface roughness post-treatment, correlating with changes in hydrophilicity and potentially impacting the moisture barrier properties of the packaging. The treated bioplastics showed improved mechanical properties, indicated by tensile strength and elongation at break. Antimicrobial testing revealed substantial efficacy against Gram-positive and Gram-negative bacteria, but not against fungi. All bioplastic samples demonstrated non-toxicity to fibroblast cells, irrespective of the treatments applied. This work paves the way for future developments targeted at improving the efficacy and scalability of plasma-nanoengineered bioplastics.