Fig. 4

Two-dimensional X-ray diffraction analysis. a Diffraction pattern and intensity at 2θ = 22.9° of G-CNC, b unstretched CNC-E, and c stretched CNC-E (250% elongation). (The value in the plots is the calculated order parameter, S). d Schematic of idealized cross section of a single CNC nanocrystal, where the blue square represents a single cellulose polymer chain that is aligned with the CNC rod axis. X-ray diffraction of the (200) plane can be found at 2θ = 22.9°. e Plot of order parameter S and birefringence ∆n relative to elongation ratio. Error bars represent s.d. of two measurements. f Schematic illustration of reorientation of CNCs from chiral nematic to a pseudo-nematic structure as the sample is stretched