*3.3. SEM Analysis*

Wheat bran morphology was investigated by scanning electron microscopy (SEM) with a FEI Quanta 450 FEG instrument (Thermo Fisher Scientific, Waltham, MA, USA). The bran powder was prior sputtered with a layer of platinum and then observed by SEM. The metallic layer makes the surface electrically conductive, allowing the electrons to generate the images. From the SEM images obtained, the dimensional distribution of the wheat bran powder was also evaluated. More than 200 particles were examined by using ImageJ® software (National Institutes of Health and the Laboratory for Optical and Computational Instrumentation, Madison, WI, USA).

In addition, the composites morphologies were investigated by SEM, on a cryogenic fractured cross-sections of tensile specimens, to evaluate the fiber-matrix adhesion and the fibers dispersion inside the matrix.
