Structural Modification Softwood Pulp Cell Wall Under Extreme Pressure Conditions 

The ability to modify the structure of the wood-pulp fibre cell wall structure is an attractive means to obtain increased accessibility to the fibre interior and enable functionalization such as controlled drug delivery, interpenetrated networks, and selective removal of metal ions from aqueous mixtures just to mention a few examples. By changing the physical state of water, it should be possible to significantly alter the structure of the wet fibre wall, providing the possibility to perform cell wall modifications under extreme conditions.

To address this challenge, we have focussed on investigating the structural development of the wet softwood kraft pulp fibre wall under high pressure High Temperature conditions (HPHT) (up to 2 GPa). The experiments aim to clarify the effect of the HPHT conditions on the porosity and the accessibility of the fibre wall for treated and untreated fibres.

The second goal is to observe the changes in the crystalline structure of cellulose due to HP conditions. Different characterization techniques including Electron microscopy, X-ray diffraction, Small and wide-angle X-ray scattering, Cross-polarized/magic angle spinning 13C-NMR are used to characterize material that have been exposed to HPHT. Key findings from the experiments relate to changes in crystallinity, specific surface area, bound water content and surface morphology.