Micro/nanostructured lignonanocellulose obtained from steam-exploded sugarcane bagasse

This work demonstrates the isolation of lignocellulose micro-nanofibrils, nanocrystals and nanospheres from steam-exploded sugarcane bagasse (SEB). First, steam-explosion was carried out in sugarcane bagasse at 195 °C for 7.5 and 15 min (SEB-7.5 and SEB-15). Untreated sugarcane bagasse was also pretreated by mechanical refining (MRB) in a PFI mill for comparison. Then, SEB and MRB fibers were subjected to alkaline delignification, hypochlorite bleaching for 60 or 180 min (HB60 and HB180), enzymatic hydrolysis (endoglucanase), and high-pressure homogenization. The resulting materials were characterized regarding chemical composition by high-performance liquid chromatography, width and morphology by transmission electron microscopy, crystallinity by X-ray powder diffraction and aspect ratio (length/diameter) by rheology. Levels of glucans (mostly cellulose), hemicelluloses and lignin were: 53.8%, 19.7% and 11.6% in MRB-HB180; 87.8%,