Processing and characterization of nanofibrillated cellulose/layered silicate systems

Recently, nanofibrillated cellulose with cationic functional groups was synthesized. This trimethylammonium-modified nanofibrillated cellulose (TMA-NFC) was applied in this study for the preparation of composites with various layered silicates. These belonged to the groups of montmorillonite, kaolin, talc, vermiculite, and mica. The respective composites were prepared by high-shear homogenization followed by filtration and hot-pressing. Data on crystal structures, chemical compositions, cation exchange capacity, specific surface area, density, and morphology of all clays and micas themselves as well as structure information of the corresponding composites have been collected. Possible microstructural features responsible for the composite appearances were tentatively identified. Principally, the interactions between TMA-NFC and the layered silicates were pronounced, due to electrostatic attraction of cationic cellulose fibrils and anionic silicate layers. This mutual interaction between TMA-NFC and layered silicate, however, was influenced not only by layered silicate properties but also by the composite preparation method, as discussed in this study.