Controlled alignment and assembly of dispersed cellulose nanofibers (CNFs) can result in materials with impressive mechanical properties and provide biobased alternatives for many advanced materials today. To improve such processes, it is crucial to understand the timescales of ion-induced assembly and how these are affected by process conditions. Additionally, it is essential to improve our understanding of ion transport through the assembled CNF hydrogel and to critically assess the hypothesis that the ion-induced assembly “locks” the oriented structure of CNFs. In this experiment, we use a shear-free flow-focusing mixing experiment combined with in-situ scanning SAXS to gain insights into the ion interactions with CNF dispersions and hydrogels. This understanding is the key to modeling and optimizing new material processes using nanocellulose including advanced filaments/hydrogels/membranes in biomedical/electrochemical applications.