Bio-inspired seaweed-based nanocomposite materials with excellent degradability and multifunctional barrier properties for green packaging

The widespread use of petroleum-based plastics brings potential hazards to the ecological environment. In order to solve this issue, the development of biodegradable materials with both high mechanical, barrier performances and food safety is imminent. In this work, a natural nacre-inspired seaweed-based nanocomposite material with the structure of “brick and mortar” is synthesized by rational assembling mica nanosheets in a mixture of glycerol and sodium alginate. The resultant SA/nano-mica film (1 wt% of phlogopite powder) shows high thermal stability (>180 °C) and exhibits great tensile strength of ∼ 16 MPa at ambient condition, surpassing some other reported nanocomposite materials (1.9–14.74 MPa). Meanwhile, the composite can be easily processed into different shapes for packaging applications, which could long-term preserve the freshness of foods owing to their strong ultraviolet (UV) shielding and gas barrier properties (UV transmittance of ∼ 4 % and oxygen transmission rates (100 µm) of ∼ 18.52 cc m−2 day−1 bar−1). Importantly, the material could completely degrade in soil within 15 days. These results indicate the great application prospect of seaweed-based nanocomposite materials in food packaging.