A NOVEL ENZYMATIC PREPARATION TECHNOLOGY OF NANOCRYSTALLINE CELLULOSE FROM BAMBOO FIBERS

Nanocrystalline cellulose (NCC), also called cellulose nanocrystals, is typically a rigid rod-shaped monocrystalline cellulose domain (whisker) with 1-100 nm in diameter and tens to hundreds of nanometers in length. Traditionally, NCC is almost prepared by acid hydrolysis and mechanical treatment, and the raw materials mainly focus on wood cellulose, microcrystalline cellulose (MCC) and animal fibres. In this contribution, enzymatic hydrolysis was chosen to produce cellulose nanocrystals. After the homogenizer, a kind of commercial cellulase, viz. enzyme Cclast (endoglucanase) was used in the process of enzymatic hydrolysis. The effect of enzymatic treatment on the morphology of the ensuing particles is reported. The prepared cellulose nanocrystals were morphologically characterized by transmission electron microscopy (TEM) and the sugar analyses of hydrolysis residues were characterized by ionic chromatography. The degree of polymerization (DP) was characterized by automatic viscosimeter. All bamboo nanofibers presented a rod-like shape, an average diameter (D) of 5.3 nm and length (L) of 221 nm, with an aspect ratio (L/D) of around 42. The use of endoglucanases allows obtaining a mixture of microfibrillated cellulose (MFC) and rod-like nanoparticles.