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

Abstract

A variety of lignocellulosic raw materials have been previously reported for the production of cellulose and cellulose derivatives, but little research effort has been dedicated to producing cellulose from Hyparrhenia filipendula. In this study, cellulose nanofibers (CNFs) were extracted from Hyparrhenia filipendula waste straws via sulphuric acid hydrolysis. MethodsThe straws were pretreated with a combination of physiochemical processes and hydrolyzed using sulphuric acid at three different concentrations (1 M, 3 M and 5.6 M) for 2 hours at 80 °C. The properties of the CNFs was checked by Fourier Transform Infrared spectroscopy (FTIR) for surface chemistry, X-ray diffraction (XRD) for crystallinity, Scanning Electron microscopy and Transmission electron microscopy (TEM) for morphology. A high-performance liquid chromatograph (HPLC) was used to quantify the amount of biopolymers in the CNFs. ResultsThe results show that CNFs, denoted as CNF 1, CNF 3, and CNF 5.6 for 1 M, 3 M, and 5.6 M sulphuric acid, respectively, were successfully extracted at the various concentrations of sulphuric acid. The cellulose content of CNF1, CNF3, and CNF5.6 determined by HPLC analysis were 85%, 77 % and 78 % respectively. Also, the hemicellulose content in CNF 1, CNF 3, and CNF 5.6 was 10 %, 15 %, and 12 % respectively, showing a high carbohydrate content of the CNFs. The FTIR spectra confirm the absence of characteristic peaks for lignin in the CNFs. The XRD analysis reveals presence of characteristic cellulose Iβ peaks at 2θ of 18°, 26°, and 40° with the crystallinity of 78%, 74 % and 73% for CNF1, CNF3 and CNF5.6, respectively. Moreover, SEM analysis shows the deposition of lignin polycondensate on the surface of CNF 1, CNF 3, and CNF 5.6 while the bleached sample has a smooth and glossy appearance. The TEM analysis shows long unbranched nano-sized fibers for CNF 1 and shorter fibrous network of fibers for CNF 3, and CNF 5.6. The average diameter of the fibers, measured with ImageJ software is 40 nm for CNF 1, 57 nm for CNF 3, and 92 nm for CNF 5.6. ConclusionCNFs were successfully produced from Hyparrhenia filipendula and reported for the first time in open literature. In view of the structure and properties of the produced CNFs, they are a potential material for value-added applications such as polymer matrices, films, and membranes, thus enabling efficient utilization of agricultural waste.

Extraction and characterization of cellulose from cotton flower burr: a noble cellulose source from agro-waste

“…However, the EC exhibits only characteristic bands associated with pure cellulose material. The spectrum shows that noncellulosic compounds were successfully removed through chemical treatments because there are no bands for hemicellulose or lignin [29,32,33]. Thus, the results demonstrate that the successful extraction of cellulose from cotton burr.…”

“…The sharp transmittance band at 1060 cm − 1 identi es the C-O stretching vibration of primary alcohol [25], and the small peak at At 2858 cm − 1 in the cotton burr, there is a peak that corresponds to C-H stretching vibrations in the aromatic methoxy, methyl, and methylene groups of lignin [27,28]. The peaks at 1735 cm − 1 and 1248 cm − 1 link to the stretching vibration of the carbonyl (C = O) group of the acetyl and urate groups present in the hemicellulose [29,30]. This band also indicates the ester group within the carboxylic functional group of phenolic acids like ferulic and p-coumaric, which are part of lignin [29,31].…”

“…Hydronium ions effectively penetrated the cellulose chains during the acid hydrolysis process, particularly targeting the susceptible amorphous regions. This facilitated the hydrolysis of glycoside bonds, eventually releasing individual crystallites [15,29,30,43].…”

“…The process began with an alkali treatment using a sodium hydroxide solution, which caused the disintegration of CB due to the removal of cementing materials from the surface. The particles in the CB are held together by hemicelluloses, lignin, and other water-soluble components that act as binders [29]. This alkali treatment disrupted some alkalilabile linkages, such as ether and ester linkages between lignin monomers or between lignin and polysaccharides.…”

Mechanical and thermal properties of recycled polyethylene/surface treated hemp fiber bio‐composites

“…[30][31][32] First, the bleaching of NF by treating with H 2 O 2 (7% vol/vol) and NaOH (4% wt/vol) (1:1 vol/vol) solution in a water bath at 60 C for 3 h 36,37 was performed. In the second stage, the H 2 SO 4 solution was in different concentrations (5%-30% (vol/vol), 50 mL) with bleached fibers at 60 C for 3 h. The concentration of H 2 SO 4 solution selected for this study was based on previous researches [38][39][40] treated. The cellulosic fibers were washed with deionized water and dried in an oven at 40 C. The effect of H 2 SO 4 concentration on the chemical extraction process was determined by XRD analysis.…”