Fabrication and characterization of bio-nanocomposite films using κ-Carrageenan and Kappaphycus alvarezii seaweed for multiple industrial applications.

In the present study, the whole seaweed from Kappaphycus alvarezii (containing carrageenan) was used for preparation of bio-nanocomposite films by blending with metal oxide nanoparticles such as zinc oxide (ZnONPs), cupric oxide (CuONPs) and silicon dioxide (SiONPs) for multiple applications, and their properties were compared with standard refined κ-Carrageenan (commercial grade). Simultaneously, the antibacterial activity and biodegradation profile of the prepared bio-nanocomposite film were also studied. The incorporation of nanoparticles into the bioplastic film matrices altered the surface morphology, increased the roughness and significantly (p < 0.05) reduced the UV transmittance, water uptake ratio (WUR), moisture content and solubility in both standard carrageenan-based bio-nanocomposite films (CBF) and Kappaphycus- based bio-nanocomposite films (KBF) compared to control. The average roughness (Ra) of KBF increased compared to CBF; however, CBF showed better tensile strength compared to KBF. Both KBF and CBF loaded with nanoparticles exhibited strong antibacterial activity against Staphylococcus aureus and Escherichia coli. However, KBF performed better compared to CBF. Antimicrobial effect of nanoparticles delayed the degradation of the bio-nanocomposite films. The present study proposes that the whole seaweed (Kappaphycus alvarezii) can be used directly for multiple industrial applications.