Nacre-Inspired Nanocomposite Films with Enhanced Mechanical and Barrier Properties by Self-Assembly of Poly(Lactic Acid) Coated Mica Nanosheets

Developing biodegradable materials such as poly(lactic acid) (PLA) is a promising strategy to reduce the reliance on non-degradable plastics and the accumulation of those wastes. However, the fabrication of high-performance biodegradable films which integrate excellent mechanical and barrier properties remains a major challenge. To address this problem, the "brick and mortar" structure, one of the most effective biomimetic models, is introduced to improve the comprehensive properties of materials. Here, a PLA-assisted exfoliation and dispersion method to prepare the PLA coated mica nanosheets (Nano-mica/PLA) from a natural mineral phlogopite is presented. By introducing the sheer force assembly, a kind of nacre-inspired nanocomposite film with the "brick and mortar" structure can be fabricated. Such a nacre-inspired nanocomposite film shows excellent mechanical properties, UV-shielding, and gas barrier properties. The overall performance of the nacre-inspired nanocomposite film is superior to commercial plastic films, which will allow it possible to break a path for practical applications of PLA in the field of packaging.