Generating in-Plane Orientational Order in Multilayer Films Prepared by Spray-Assisted Layer-by-Layer Assembly.

We present a simple yet efficient method for orienting cellulose nanofibrils in layer-by-layer assembled films through spray-assisted alignment. While spraying at 90° against a receiving surface produces films with homogeneous in-plane orientation, spraying at smaller angles causes a macroscopic directional surface flow of liquid on the receiving surface and leads to films with substantial in-plane anisotropy when nanoscale objects with anisotropic shapes are used as components. First results with cellulose nanofibrils demonstrate that such fibrils are easily aligned by grazing incidence spraying to yield optically birefringent films over large surface areas.

Ionically interacting nanoclay and nanofibrillated cellulose lead to tough bulk nanocomposites in compression by forced self-assembly.

Several approaches have recently been shown for self-assembled biomimetic composite films, aiming at combinations of high toughness, strength, and stiffness. However, it remains challenging to achieve high toughness using simple processes especially for bulk materials. We demonstrate that ionically interacting cationic native nanofibrillated cellulose (C-NFC) and anionic nanoclay, i.

Adhesive layer-by-layer films of carboxymethylated cellulose nanofibril-dopamine covalent bioconjugates inspired by marine mussel threads.

The preparation of multifunctional films and coatings from sustainable, low-cost raw materials has attracted considerable interest during the past decade. In this respect, cellulose-based products possess great promise due not only to the availability of large amounts of cellulose in nature but also to the new classes of nanosized and well-characterized building blocks of cellulose being prepared from trees or annual plants. However, to fully utilize the inherent properties of these nanomaterials, facile and also sustainable preparation routes are needed.

Nanocelluloses: a new family of nature-based materials.

Cellulose fibrils with widths in the nanometer range are nature-based materials with unique and potentially useful features. Most importantly, these novel nanocelluloses open up the strongly expanding fields of sustainable materials and nanocomposites, as well as medical and life-science devices, to the natural polymer cellulose. The nanodimensions of the structural elements result in a high surface area and hence the powerful interaction of these celluloses with surrounding species, such as water, organic and polymeric compounds, nanoparticles, and living cells.

Colloidal ionic assembly between anionic native cellulose nanofibrils and cationic block copolymer micelles into biomimetic nanocomposites.

We present a facile ionic assembly between fibrillar and spherical colloidal objects toward biomimetic nanocomposites with majority hard and minority soft domains based on anionic reinforcing native cellulose nanofibrils and cationic amphiphilic block copolymer micelles with rubbery core. The concept is based on ionic complexation of carboxymethylated nanofibrillated cellulose (NFC, or also denoted as microfibrillated cellulose, MFC) and micelles formed by aqueous self-assembly of quaternized poly(1,2-butadiene)-block-poly(dimethylaminoethyl methacrylate) with high fraction of the NFC reinforcement. The adsorption of block copolymer micelles onto nanocellulose is shown by quartz crystal microbalance measurements, atomic force microscopy imaging, and fluorescent optical microscopy.