Cellulose regeneration from dope induced by water diffusion as monitored by simultaneous small- and wide angle X-ray scattering

Structure formation during the processing from highly concentrated solution dope is a crucial step in controlling the final material properties in solution processing, including fibre spinning, membrane generation or fabrication of other functional materials. The regeneration of cellulose by a nonsolvent is a complex process involving diffusion of non-solvent into the dope, diffusion of different solvent molecules into the coagulation bath and the structure formation and swelling or contraction of the regenerating gel. The combination of small- and wide angle X-ray scattering allows the monitoring of the diffusion process and the structure formation at different length-scale. The regeneration behaviour from solvents attaining high (~10%) cellulose concentration dope, namely NMMO monohydrate and [DBNH][OAc] will be discussed.