Quantitative Evaluation of the Influence of Densification Process on Bamboo Cell Walls

The densification process, namely, a combination of compression and thermal modification is an effective way to enhance the mechanical and physical properties of bamboo in the field of construction. In the work, surface morphology, wet chemistry method, and micro-mechanical properties were analyzed after the densification process, which showed that the densification process resulted in a decline in the porosity of bamboo cell wall. The content of hemicellulose and cellulose decreased, while the relative content of lignin increased. XPS was used to carry out the quantitative analysis of the change of C/O ratio. The results of nanoindentation showed that the elastic modulus and hardness increased from 13.5 GPa and 0.7 GPa for the control to 17.7 GPa and 0.9 GPa for the densified bamboo. These findings confirmed that the densification process makes a positive contribution to micro-mechanical properties of bamboo cell walls. In addition, densification may also be related to the development of bamboo-based materials.