Hydration-driven structural evolution in cross-linked cellulose-based xerogels probed by 2DCOS and PCMW2D correlation...

Area of Science:

• Materials Science
• Polymer Chemistry
• Spectroscopy

Background:

• Cellulose nanofiber (CNF) based materials offer unique properties for various applications.
• Understanding the structural dynamics of CNF composites is crucial for optimizing their performance.
• Branched polyethyleneimine (bPEI)/cellulose nano-sponges (CNSs) are novel composite materials with tunable properties.

Purpose of the Study:

• To investigate the sequence of structural changes in bPEI/TOUS-CNF xerogels upon hydration.
• To analyze cross-correlations between structural moieties at different length scales.
• To reveal subtle structural transitions not evident from conventional analysis.

Main Methods:

• Small-angle neutron scattering (SANS) data analysis.
• Generalized two-dimensional correlation spectroscopy (2DCOS).
• Perturbation-correlation moving window 2D correlation spectroscopy (PCMW2D).

Main Results:

• The study identified structural transitions in CNSs at different hydration levels and cross-linker amounts.
• 2DCOS and PCMW2D revealed cross-correlations between structural changes at various length scales.
• The combined spectroscopic approach demonstrated higher sensitivity in detecting polymer arrangement dynamics compared to conventional SANS.

Conclusions:

• The application of 2DCOS and PCMW2D on SANS data provides novel insights into the structural dynamics of CNSs.
• This method is effective in detecting subtle structural changes and transitions in polymer-based materials.
• The findings enhance the understanding of CNS structure-property relationships, aiding in material design.