Cellulose filaments (CFs) are recently-developed materials derived from wood pulp, consisting of very long, thin cellulosic strands. These filaments can be incorporated into a number of high-value non-traditional products, such as thermoset and thermoplastic composites, and can be used as rheology modifiers in fluids such as paints and various industrial fluids. However, the ‘raw’ filaments require upgrading before they can be used for these non-traditional applications.