Fig. 4From: From nano- to micrometer scale: the role of microwave-assisted acid and alkali pretreatments in the sugarcane biomass structureGlobular structures on the cell wall surface of the mw-acid-pretreated fibers. AFM amplitude (a) and phase (b) images of the mw-acid at the temperature of 160 °C for 30 min. Scan area of 2 × 2 µm. Lignin droplets are indicated by black arrowsBack to article page