Fig. 3.

a Cross-sectional SEM images of the whole bamboo treated with different delignification methods. b Longitudinal-sectional SEM images of parenchyma cells of the whole bamboo treated with different delignification methods. c Schematic diagram of the variation of bamboo fiber bundles and matrix cells treated with a mixture of hydrogen peroxide and acetic acid. d Variation of weight loss rate and relative lignin content of samples in acidic sodium chlorite solution. e Variation of weight loss rate and relative lignin content of samples in the mixed solution of hydrogen peroxide and acetic acid