Synergistic effect of cell structure and surface engineering: High-Aspect-Ratio nanofiber production and applications from bamboo pulp waste

Bamboo pulp fines (BPF) are defined as bamboo pulp waste. BPF, including fine fibers and abundant non-fibrous cells, are detrimental to the performance of paper and are usually regarded as waste and discarded. In this work, inspired by the loose structure of non-fibrous cell walls in bamboo, a mild method for converting BPF into CNFs was developed. By leveraging the loose structure of BPF, high-density surface carboxyl groups were introduced via low-toxic (relatively less hazardous than nitro-based oxidants) maleic anhydride (MAH) esterification reactions, significantly enhancing dispersibility and interfacial compatibility. Combined with gentle mechanical disintegration, successfully resulting in CNFs (M−CNFs) with a diameter of approximately 2.6 nm, an aspect ratio exceeding 1000, a carboxyl content of 1.45 mmol/g, and a yield of approximately 98%. Furthermore, M−CNF−based nanofilms exhibited exceptional mechanical properties, achieving 107 MPa tensile strength with unique stress-dispersion mechanisms. The resulting M−CNFs serve as sustainable building blocks for multidimensional advanced cellulose materials and emulsion stabilizers. This method-produced M−CNFs offer advantages including ultrahigh aspect ratios, colloidal stability, high yield, and significant application potential, establishing a high-value valorization route for bamboo pulp waste.