Morphological Analyses of Some Micro- and Nanofibrils from Birch and Wheat Straw Sources

The morphological properties of nano- and microcellulose depend on the source of the particles, the preparation methods, and the processing conditions. In this study, two different kinds of microfibrillated (MFC) and nanofibrillated (NFC) celluloses were produced from wood and non-wood cellulose pulps through mechanical methods without using any chemicals. The morphological properties of the samples and feasibility of different analysis methods were investigated using a novel chromatographic washer, a field emission scanning electron microscope (FESEM), a laser diffractometer (LS), a rotational viscometer, X-ray diffractometry (WAXD) and, additionally, the degree of polymerization (DP) was assessed. The analyses showed that the formed non-wood cellulose fibrils were shorter than the wood cellulose fibrils, but wheat straw pulp comminuted to nanofibrils more easily. The low hemicelluloses content of wheat straw pulp caused the flocculation of the nanofibrils formed in homogenization. All of the analytical methods reflect morphological differences between the micro- and nanocellulose materials.