Figure 6: Spectral evolution of the cellulose absorptions in the fingerprint region for the gelling of SPS, shown for scans selected at different temperatures and different stages at 85°C. The background signal from NaOH/urea solvent without cellulose at the same experimental stage was subtracted. The spectra are offset by 0.001 absorbance units for clarity. Bands for relevant peaks are marked by vertical lines.