Fig. 2: Fiber diffraction patterns collected from cellulose I nanocrystals after mercerization to cellulose II.

The figure is a composite of quadrants from 4 patterns. Top left quadrant: using X-rays. Top right quadrant (CD): using neutrons with H in all nanocrystals replaced by D. Bottom right quadrant (CH): using neutrons with no D present. Bottom left quadrant (CDH): using neutrons with H in half of the nanocrystals replaced by D (CDH). The black circle in the center of the image represents the position of the direct beam as it passes straight through the sample. The vertical, meridional, direction corresponds to the direction of the fiber axis and the cellulose chains. The equator of the diffraction pattern passes horizontally through the beam center and corresponds to the packing direction of neighboring cellulose chains. The position of the (002) meridional and (1−10) equatorial diffraction intensities is indicated by arrows. The relative differences between the diffracted neutron intensities in (CD), (CH), and (CDH) are due to different distributions of H and D within the samples. The pattern of white lines in these neutron diffraction patterns is due to the way the data are folded together from several different detector positions, as described previously¹³.