Percolation Model for Renewable-Carbon Doped Functional Composites in Packaging Application: A Brief Review

This review summarizes the application of percolation theory for the behavior simulation of renewable-carbon in its doped packaging composites. Such dopant-reinforced materials have sparked considerable interest due to the significant improvement on the aesthetic and mechanical properties at considerable low filler content (<1% in some cases), which would further boost their potential use in the food and pharmaceutical packaging industries. We focused mainly on the percolation behavior, which is closely related to the distribution of renewable carbon particles in the presence of polymeric matrix. The effect of geometry, alignment and surface property is of particular relevance to the percolation threshold of composites containing carbon fillers. Validity, as well as limitations of the mostly used percolation models, is further discussed. Finally, despite its recent emergence as functional filler, carbon-based nanocellulose has been extensively developed for a wide range of applications. This inspired the concept to use nanocellulose as a secondary bio-additive for packaging purposes, such as functional nanocellulose-coated film where primarily synthetic polymers are used. The microstructure and functionality of rod-like nanocellulose in its use for film composite are specifically discussed.