Nanostructural characterisitics and changes of cellulose aqueous hydroxide solutions

Research Project, 2019 – 2020

Purpose and goal: The goal of the project is to develop knowledge and methodology necessary to probe the nanostructure of cellulose solutions in aqueous hydroxide bases by small-&wide angle X-ray scattering, aiming at understanding interactions determining their structure and stability. Our findings indicate a moderate hydrophobicity and spacer action of the cation as important stabilizing factors. However, a comprehensive understanding calls for elucidation of the accompanying nanostructural features: geometry of the chains, their aggregates and alterations upon changed conditions. Expected results and effects: The results will decisively complement our molecular level findings and open up for tailoring of cellulose aggregation behavior, important for large scale implementation. Methodology and theoretical knowledge, applicable to cellulose and polysaccharides solution in general will be incorporated in the PhD student´s tool box. Close collaboration will, apart from developing a hybrid competence required for the intended studies, promote a broader knowledge exchange important for utilization of scattering methods in biomass research in general (e.g. sample preparation). Approach and implementation: The project is structured around following activities: 1) Conformation/aggregation of dissolved cellulose will be probed as functions of dissolution conditions through temperature sweep measurements on solutions of varying composition. 2) Aggregation behaviour will be monitored in time on selected solutions. 3) Complementary in situ experiments will be performed employing the microfluidics approach: the solutes are brought together through a so called T-channel mixing, the spatial resolution on the channel will provide a time-resolved structural information