2.6. Measurement of crystallinity
Crystallinity of wood particles was measured by an X-ray
diffractometer (Model MiniFlex II, Rigaku Americas Corp., The
Woodlands, TX, USA). The X-ray source was a ceramic X-ray tube
with Cu anode. Operating power was 30 kV and 15 mA (450 W).
X-ray diffraction patterns of samples were recorded at room temperature
with a scan range from 10_ to 45_. The step size of the
scan was 0.05_. CI was calculated using the Segal method (Segal
et al., 1959) as the height ratio between the intensity of the crystalline
peak (I002–IAM) and total intensity (I002) after subtracting
the background signal measured without any biomass sample.
For each size reduction condition, three particles were randomly
chosen for CI measurement.