Functionalized cellulose structures from aqueous alkaline systems

“Even though aqueous alkaline systems are among the most prominent and sustainable conversion media for cellulose (of particular importance for large scale processes) fundamental understanding of principal molecular interactions in these systems is still limited, especially of those stabilizing cellulose solutions in aqueous alkali. However, regardless of the nature of stabilizing interactions in these solutions, their combined effect is generally insufficient to overcome the extensive cellulose-cellulose interactions. As a consequence, aqueous alkaline cellulose solutions behave (unless highly diluted) as meta-stable systems of mutually associated chains prone to re-associate and gel. While this limited stability accompanied with gelling is problematic when regenerating cellulose solutions into spun textile fibers, self-aggregation to gel structures can be employed in material design in a broader sense. Either way, comprehensive understanding of cellulose-cellulose interaction leading to re-association is a prerequisite for development of well-controlled processes and a broader utilization of cellulose solutions in aqueous alkali. Particularly attractive is the possibility of utilizing cellulose reactivity (and thus its chemical conversions) in these solutions as a means of governing re-association of the chains and controlling material properties of the resulting hydrogels. The project is conducted within the Wallenberg Wood Science Center.”