Fabrication of food-safe superhydrophobic cellulose paper with improved moisture and air barrier properties.

We presented a facile method for preparing a food-safe superhydrophobic packaging paper with improved moisture and air barrier properties in this study, which is combining construction of polymer-nanoclay hybrid multilayers with subsequent carnauba wax treatment. The polymer-nanoclay hybrid multilayers consisting of quadlayers of carrageenan (CR)/chitosan (CS)/montmorillonite (MMT)/CS were created using layer-by-layer (LbL) assembly. The surface chemical compositions, potentials and morphologies of the CR/CS/MMT/CS multilayer-modified paper samples were investigated. The paper sample modified with a wax-treated (CR/CS/MMT/CS)2 multilayer gave a water contact angle of 151.4°. Compared with original paper, this superhydrophobic paper sample showed comparable tensile strength and excellent barrier properties against water vapor and air. Moreover, the obtained paper was used for strawberries packaging at ambient temperature, and it was very effective at reducing the weight loss and maintaining titratable acidity compared with the unpackaged strawberries, which might has a great potential as food packaging materials.