Nanocellulose/polymer multilayered thin films: tunable architectures towards tailored physical properties

This article reviews the recent development of nanocellulose/polymer multilayered films. The layer-by-layer assembly technique has been used for about a decade to build thin films composed of alternating layers of either cellulose nanocrystals (CNCs) or cellulose nanofibrils (CNFs) with different polymers (e. g. synthetic polycations or neutral biopolymers). We show that the resulting architectures, which have been probed using various surface-sensitive techniques, are highly tunable and depend on the individual properties of the constituents, the interaction forces between the nanocellulose and the polymer and the deposition method parameters. The composition and morphology of these fully biobased or hybrid fossil/natural nanocomposite films can be precisely tailored to achieve different physical properties that have been investigated. We describe how high performance thin films and coatings with advanced functionalities can be designed and potentially used in the fields of permeation membranes, bioenergy production, drug delivery, flexible electronics, controlled adhesion or optical protective coatings.