Nanocomposites of Bacterial Cellulose Nanofibrils and Zein Nanoparticles for Food Packaging

The pursuit of sustainable high-performance nanocomposite materials requires the development of nanoscale building blocks based on natural renewable resources and efficient facile production methods. Here, we show a simple, fast, and environmentally friendly route to construct a mechanically robust and multifunctional nanocomposite by using bacterial cellulose nanofibrils (BCNs) and protein zein nanoparticles (ZNs) as natural building blocks. The nanoparticles ZN are successfully incorporated into the BCN networks forming a homogeneous nanopaper composite by a well-established scalable papermaking process. The resulting BCN-ZN nanocomposites display markedly improved tensile mechanical properties and thermal stability, which mainly result from the strong interfacial adhesion and interactions between ZN nanoparticles and BCN matrix induced by hydrogen bonds. Moreover, after the incorporation of ZN, the biocompatibility of the nanocomposites is also enhanced due to the formation of rougher surface structure as well as the good biocompatibility of edible zein. More particularly, the multifunctional BCN-ZN nanocomposites with diverse activities such as antibacterial properties are fully achieved by encapsulating various hydrophobic active cargoes into the versatile nanocarrier ZN. Considering the facile and green preparation process, and the use of all-natural, sustainable ingredients, we expect these mechanically robust and multifunctional BCN-ZN nanocomposites to promote the development of cellulose nanofibril-based nanocomposite materials for sustainable applications in food packaging.