Preparation of Cellulose Nanofibers from Bagasse by Phosphoric Acid and Hydrogen Peroxide Enables Fibrillation via a Swelling, Hydrolysis, and Oxidation Cooperative Mechanism

Abstract

Due to the natural cellulose encapsulated in both lignin and hemicellulose matrices, as well as in plant cell walls with a compact and complex hierarchy, extracting cellulose nanofibers (CNFs) from lignocellulosic biomass is challenging. In this study, a sustainable high yield strategy with respect to other CNF preparations was developed. The cellulose was liberated from plant cell walls and fibrillated to a 7–22 nm thickness in one bath treatment with H3PO4 and H2O2 under mild conditions. The cellulose underwent swelling, the lignin underwent oxidative degradation, and the hemicellulose and a small amount of cellulose underwent acid hydrolysis. The CNFs’ width was about 12 nm, with high yields (93% and 50% based on cellulose and biomass, respectively), and a 64% crystallinity and good thermal stability were obtained from bagasse. The current work suggests a strategy with simplicity, mild conditions, and cost-effectiveness, which means that this method can contribute to sustainable development for the preparation of CNFs.

Fabrication and Characterization of Degradable Crop-Straw-Fiber Composite Film Using In Situ Polymerization with Melamine–Urea–Formaldehyde Prepolymer for Agricultural Film Mulching

“…The degradation process of the straw fiber film included the following stages: (1) the appearance of tiny pores, (2) the appearance of huge pores and large-area rupture, and (3) breaking into small pieces [ 47 , 48 , 49 ]. The process, which led to thinning, brittleness, and loss of mechanical properties, is shown in Figure 8 .…”

Extraction and Characterization of Cellulose Nanofibers From Yellow Thatching Grass (Hyparrhenia filipendula) Straws via Acid Hydrolysis

“…Nonetheless, there are notable differences in the FTIR spectra between the samples. The absence of the characteristic absorption peak at 1730 cm −1 ( C= O stretching of the acetyl and urate groups of hemicellulose, or the ester bond of carboxyl groups in lignin to fragrant acid and ferulic acid) in the CNFs shows that lignin and hemicellulose were significantly removed in the CNFs [38]. Additionally a shift in the peak at 1629 cm -1 in the raw sample to 1642 cm -1 for CNF1, CNF3 and CNF 5.6 indicates a conversion cellulose I to cellulose II during treatment, as reported by other authors [38].…”

“…The absence of the characteristic absorption peak at 1730 cm −1 ( C= O stretching of the acetyl and urate groups of hemicellulose, or the ester bond of carboxyl groups in lignin to fragrant acid and ferulic acid) in the CNFs shows that lignin and hemicellulose were significantly removed in the CNFs [38]. Additionally a shift in the peak at 1629 cm -1 in the raw sample to 1642 cm -1 for CNF1, CNF3 and CNF 5.6 indicates a conversion cellulose I to cellulose II during treatment, as reported by other authors [38]. The FTIR spectra also showed a peak at 1510 cm −1 , characteristic of lignin, only for the raw and pulped sample, confirming significant delignification of the CNFs [37].…”

Production of cellulose nanofibrils and films from elephant grass using deep eutectic solvents and a solid acid catalyst

“… 2 The production of CNFs from wood or plant biomass is challenging because cellulose is encapsulated in a matrix of lignin and hemicellulose with a compact and complex hierarchy structure in plant cell walls. 3 The most common approach to produce CNFs usually requires first removing the non-cellulose components and bleaching the residues through alkaline and acid-chlorite treatments. 4 Then, the extracted cellulose is mainly degraded by mineral acid hydrolysis pretreatment combined with mechanical disintegration to provide CNFs.…”