The micro/nanofibrillated celluloses present high intrinsic tensile properties and high aspect ratio, which result in good reinforcing potential when used in composite materials. 17,19 Furthermore, they have the ability to form dense films, with nanoporous structures, which can provide gas barrier effects similar to those of synthetic polymer films. In dry athmosphere, the oxygen permeability of neat MFC films is comparable to that of ethylene co-vynil alcohol (EVOH) copolymer, but it is subtantially lower than that of polyvinilidene chloride (PVDC) or polyethylene terephtalate (PET) films with the same thickness. 17,20 Therefore, further development in obtaining and application of nanocelluloses could offer alternatives to synthetic polymer films for barrier properties of packaging paper, along with mechanical strength improvement.