Characterization of fibrillated celluloses. A short review and evaluation of characteristics with a combination of methods

The most important properties of fibrillated celluloses and the state-of-the-art methods for their characterization are discussed on the basis of literature review and our collective experience on the material. Five mechanically manufactured fibrillated celluloses were analysed with a combination of methods, revealing information on their morphology, rheological properties, average size and size distribution and amount of the true nano-sized material. The results showed that the studied samples differed greatly in their properties. The phenomena behind their behaviour proved to be complex, and any single characterization method cannot be used to describe their properties and behaviour. Instead, a combination of methods based on different measuring principles must be applied. Based on the results, a basic characterization package can now be recommended for chemically un-modified fibrillated celluloses, including shear viscosity and transmittance measurements, as well as evaluation of appearance, morphology and fibril size by optical and electron microscopy.