Fig. 8

FTIR analysis of crystalline, swollen, and gelatinized states of cotton linter cellulose. a Area-normalized averaged spectra of crystalline cellulose standard, and TFA-treated cellulose treated at − 20 °C for 15 h, with and without a subsequent treatment of 55 °C for 5 h. Each spectral line is the average of 25–30 technical replicates. b Principal Component Analysis of the individual spectra from each treatment. Each replicate is the sum of 128 co-added FT spectra that were area-normalized. c Subtraction spectra of the baseline-corrected and area-normalized averaged spectra shown in a. d Principal component loadings used in PC shown in b. Inset Percentage of correct classification of spectra with treatment with increasing PCs