Layer-by-layer (LBL) assembly technique, based on sequential adsorption of oppositely charged compounds, continues to be one of the most popular and well-established methods for formation of multilayered thin films. Wide variety of species available has led to a number of potential research and industrial applications in semiconductors, catalysts, optics, magnetic devices, and sensors. In addition, we have also shown that LBL technique allows for preparation of architecturally and mechanically unique composites from carbon nanotubes and clay nanosheets with record high strengths.

Having at hand the versatility of the technique and large library of available assembly components we continue to develop new materials with unique properties. We present here our results from two distinct materials: clay nanosheets and cellulose nanocrystals. Given the results of exceptional mechanical properties in the clay/polymer films, we have investigated improvement of the strength further through different approaches: replacement of the polymeric matrix with macroscopically stronger material, heat-treatment of the composite, chemical crosslinking and increasing interaction between the two components. The results show that novel composites with improved mechanical properties can be developed with this method. For the cellulose nanocrystals, we show that LBL technique affords preparation of novel, cheap and high strength thin film composites with improved mechanical properties when compared to other preparation methods.