From Biomass to Nanomaterials: A Green Procedure for Preparation of Holistic Bamboo Multifunctional Nanocomposites Based On Formic Acid Rapid Fractionation

To achieve full utilization of lignocellulosic biomass and easy integration of nanomaterials production, it is essential to develop an efficient fractionation to overcome the highly recalcitrant nature of lignocellulose and facilitate the subsequent valuable conversion. Herein, in a combined process based on the formic acid rapid fractionation of bamboo chips, pure cellulose, and lignin were first obtained as fractionated streams. Compared to wood kraft pulp, the bamboo-originated cellulose was easily converted into cellulose nanocrystals (CNCs) using TEMPO oxidation in a relatively short time, which holds greater potential to meet the commercial cost target. The dissolved lignin was processed into nanoparticles (lignin NPs), which exhibited spherical morphology and a uniform particle size distribution. Dispersions of CNCs and lignin NPs were prepared and further filtrated to form nanocomposite membranes. The nanocomposite membranes exhibited a very smooth surface and homogeneous structure. Most impressively, at the CNCs/lignin NPs ratio of 5, the tensile strength and Young's modulus were improved by 44 and 47%, respectively, compared to the pure CNCs film. Owning to the presence of lignin NPs, and the nanocomposites exhibited an effective antibacterial activity against E. coli.