Nanostructural characterisitics and changes of cellulose aqueous hydroxide solutions

Purpose and goal

The main objective of the project was to generate methodology knowledge and experience required for scattering investigations (SAXS/WAXS) of nanostructural organization of aqueous cellulose solutions. By connecting nanostructural with the already existing information on molecular level an important step towards comprehensive understanding of stability (and thus processabilty) of these solutions would be taken. The studies pointed out a clear correlation between the base composition and chain conformation, with the quaternary ammonium bases dictating stiffer chains.

Expected results and effects

Methodology for sample preparation, instrumentation and post-processing of raw data (including work on interpretation models) was developed and became a part of the PhD-student´s and the group´s analytical tool box. The contact with the synchrotron facilities including the application process for beam time is an important experience that will promote future use of this infrastructure. A new knowledge on the structure of aqueous cellulose solutions has been gained (a manuscript in preparation, "Scattering studies of the cellulose structure in aq hydroxide base solutions").

Planned approach and implementation

Nanostructural organisation of aqueous cellulose solutions in hydroxide bases has been analyzed by SAXS/WAXS. Cellulose concentration, hydroxide base composition (quaternary ammonium hydroxides of varying size and hydrophobicity were combined with NaOH) and temperature have been varied and the solutions investigated in terms of geometry and aggregation of the chains (SAXS). WAXS studies were used to probe the organization/crystallinity of the aggregated and undissolved fractions. Access to synchrotron time was applied for (for complementary studies) without any success.