A novel method to prepare lignocellulose nanofibrils directly from bamboo chips

Nanocelluloses, including cellulose nanocrystals (CNCs), bacterial nanocellulose (BNC), and cellulose nanofibrils (CNFs), have attracted much attention in recent years all over the world. However, commercial applications of nanocelluloses are still limited due to the high cost of nanocelluloses. In this study, we developed a novel method to prepare lignocellulose nanofibrils (LCNF) directly from bamboo chips (BC), which can readily be scaled up. The method developed consists of three primary steps, which are as follows: glycerol pretreatment, screw extrusion, and mechanical refining/milling in a colloid mill. Glycerol can readily penetrate into bamboo chips and it is used as an effective reaction medium for fibrillation and delignification. The LCNF yield is about 77.2% based on bone dry bamboo chips. The morphology of the LCNF was investigated by transmission electron microscopy (TEM), which shows that the LCNFs have a diameter of 20-80nm and a length of several thousand nanometers. X-ray diffraction (XRD) analysis shows that the crystallinity of the LCNF was 52.7%, which was slightly lower than that of the bamboo raw material. This process can be easily scaled up for commercial production of LCNF.