Peak-force quantitative nanomechanical mapping of cellulose isolated from garlic and agave residues

The mechanical properties of the cellulose cell wall in garlic and agave were investigated through peak-force quantitative nanomechanics mapping (PFQNM) in atomic force microscopy. This study facilitates the mapping of elastic modulus (Young's modulus) with nanometer lateral resolution in lignocellulosic samples before and after cellulose isolation. For the calculation of elastic modulus, the Derjaguin–Muller–Toporov (DMT) model was used and values of DMT modulus (GPa) were obtained for garlic skin and agave fibers, as well as cellulose garlic and agave after isolation. PFQNM allows finding differences in height, adhesion, and DMT modulus between the raw and isolate samples; higher values of DMT modulus are associated with a hard material and lower values with a softer material, revealing that cell wall configuration in garlic skin (11.64 ± 0.37 GPa) is less rigid than cell wall agave fibers (19.88 ± 2.53 GPa). Comparable values of reliable stiffness in the materials after isolation (20–21 GPa) were found. This research involves relevant information about the characterization of cellulosic materials in plant-based samples with nanomechanics methods which are scarcely studied nowadays. Graphical abstract: [Figure not available: see fulltext.].