Mechanical imaging of bamboo fiber cell walls and their composites by means of peakforce quantitative nanomechanics (PQNM) technique

Abstract The mechanical properties of cell wall layers of bamboo fibers (BFs) and the interphase between BFs and maleated polypropylene polymer (MAPP) were investigated by means of peakforce quantitative nanomechanics based on atomic force microscopy. This technique is well suited for simultaneous imaging of several important material indicators, such as elastic modulus, deformation at peak force, and adhesion force between probe tip and sample. Furthermore, quantitative local mechanical information could be extracted from the obtained images by means of profile analysis. In case of BFs, the elastic modulus of the secondary cell wall and the compound middle lamella was found to be 21.3±2.9 GPa and 14.4±3.6 GPa, respectively, which agrees well with data measured by the nanoindentation technique. Additionally, this technique was also applied for bamboo plastic composites, and data from the transitional zone (interphase) between BFs and the MAPP matrix, with a thickness of 102±18 nm, could be obtained.