Carboxylated nanocrystalline cellulose from Salix psammophila prepared by sulfuric acid hydrolysis combined with 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)-oxidation

Abstract

Salix psammophila (SP) is an important sand plant, and could be utilized to develop high-value products. In this work, SP was used as raw material and cellulose nanocrystals (CNC) were prepared by hydrolysis in 64 wt% sulfuric acid (H2SO4) solution, and then, TEMPO/NaBr/NaClO system was used to oxidize CNC to obtain TEMPO-oxidation-cellulose nanocrystals (TOCNC). Fourier transform infrared analysis (FTIR) revealed that after oxidation, there were obvious carboxyl functional groups. Scanning electron microscopy (SEM) showed that both CNC and TOCNC were agglomerated. Under atomic force microscope (AFM) and transmission electron microscopy (TEM), CNC and TOCNC presented short rod fibers, average diameters of 23 nm and 21 nm and average lengths of 213 nm and 165 nm, respectively. X-ray photoelectron spectroscopy analysis (XPS) showed that TOCNC generated a new energy spectrum peak at 289.06 eV, which was the peak of C=O in the carboxyl group. The crystallinity of the CNC and TOCNC were 70.8% and 26.9%, respectively.

Ultrasonic-assisted in situ synthesis of MOF-199 on the surface of carboxylated cellulose fibers for efficient adsorption of methylene blue

“…S1 † shows the infrared spectra of CCF versus untreated virgin cellulose fibers (CF), CCF shows a distinct infrared characteristic peak at 1600 cm −1 compared to CF, which is attributed to the asymmetric contraction vibration of –COO–, indicating successful oxidation of CF. 23 The peak around 3300 cm −1 is attributed to the O–H stretching vibration, this comes from physically adsorbed water. 24 The bands at 490 cm −1 in MOF-199 and MOF-199/CCF are attributed to the Cu–O metal–oxygen bond, and the peaks at 728 cm −1 and 761 cm −1 are attributed to C–H stretching.…”

Synthesis, characterization and application of nanocrystalline cellulose: A review

“…It can be used to determine the size, shape, and distribution of the particles. TEM results from several researchers showed that NCC are needle-like or rod like in shape [42,43].…”

Hydrothermal liquefaction of Salix psammophila in the presence of ionic liquid and water

“…As a lignocellulosic biomass, cellulose, hemicellulose, and lignin are the main components of S. psammophila. In recent years, the liquefaction of this plant under sulfuric acid, nitric acid, or hydrochloric acid catalysis have been studied (Zhong et al 2020(Zhong et al , 2022. However, it is well established that the highly hydrogen-bonded cellulose component cannot be easily dissolved in any conventional solvents (Maldas and Shiraishi 1997).…”