High-resolution solid-state 13C NMR and NIR diffuse reflectance spectra were obtained on microcrystalline and "noncrystalline" celluloses. Particle sizes and relative crystallinity were confirmed by scanning electron microscopy and MIR transmission spectroscopy, respectively. The results showed that NMR is more sensitive to order changes and less sensitive to particle size. NIR reflectance, on the other hand, is very sensitive to particle size changes and essentially insensitive to differences in order.
D. S. Himmelsbach, F. E. Barton, and D. E. Akin, "Comparison of Responses of 13C NMR and NIR Diffuse Reflectance Spectroscopies to Changes in Particle Size and Order in Cellulose," Appl. Spectrosc. 40, 1054-1058 (1986)