Crystalline Structure Of Cellulose Research Articles

The Effect of Assam Silk Fibroin on the Bacterial Cellulose Cytocompatibility as the Extracellular Matrix

AbstractThe growing interest in natural polymers for biomedical and tissue engineering has fueled the search for materials with superior mechanical and biological properties. Bacterial cellulose (BC) and silk fibroin (SF) emerge as promising candidates meeting these criteria. This study focuses on enhancing BC through high‐pressure homogenization (HPH) and subsequent functionalization with Assam silk fibroin (ASF) using an ex‐situ approach. Analysis via attenuated total reflection–Fourier transform infrared (ATR–FTIR) spectroscopy confirms the successful integration of ASF into the HPH‐treated BC scaffold. The diffractogram of HPH‐BC/ASF indicates the prevalence of type I cellulose crystalline structures, with variations in lamellar and porous architecture based on component ratios. Mechanical testing, particularly the compressive test, reveals that the HPH‐BC/ASF formulation exhibits the highest compressive stress and modulus compared to other samples. Supplementary analyses, including swelling ratio and porosity measurements, support the superior compressive properties of HPH‐BC/ASF. Moreover, the cell viability of chondrocytes demonstrates compatibility with the BC‐based scaffold material. These findings underscore the potential applications of HPH‐BC and ASF in areas such as scaffolding for the development of extracellular matrix.

Effect of High-Intensity Microwave Treatment on Structural and Chemical Characteristics of Chinese Fir

High-intensity microwave (HIMW) treatment is a time-saving and environmentally friendly method widely applied in the wood processing industry. It enhances wood permeability, making it suitable for drying and impregnation modification. This study aimed to investigate the effects of HIMW on macroscopic and microscopic cracks, tracheid cell wall damage, and the chemical structure of Chinese fir [Cunninghamia lanceolata (Lamb.) Hook] wood. Through the use of a camera, optical microscope, scanning electron microscope, transmission electron microscope, Fourier-transform infrared spectroscopy, and X-ray diffraction, the morphology of cracks, cell wall damage, the chemical composition of the cell wall, and the crystalline structure of cellulose treated with HIMW were examined and analyzed. The results revealed that the initial moisture content (MC) and microwave energy density (MWED) significantly influenced the crack characteristics and cell wall structure and slightly influenced the chemical composition and crystalline structure of cellulose of the Chinese fir cell wall. HIMW treatment can produce different characteristics of wood cracks. The size and number of cracks were significantly increased with the increase in MWED, and more cracks were found in low MC. Microcracks caused by HIMW treatment tended to initiate at the ray parenchyma, resulting in the stripping of ray cells along its radial direction. Meanwhile, the cracking of adjacent cell junctions, the rupturing of the pit margo and pit torus, and cell wall parts tearing along the direction of microfibers occurred as a result of the HIMW treatment. The most severe damage to the cell walls occurred at the interface of S1/S2, S1, and ML layers, and the cell walls were torn in the S2 layer. There were no significant changes in the FTIR spectra of the HIMW treatment samples. Hemicellulose degradation occurred first, which increased with the increase in MWED. The recrystallization of cellulose and the lignin content increased because of the change in the aromatic C=O groups. As MWED increased, both the crystallinity index (CI) and cellulose crystal width (D200) of the samples that underwent HIMW treatment increased accordingly, and the number of low-MC samples was greater than that of the high-MC samples. The findings contribute to understanding the crack characteristics and damage mechanism induced by HIMW treatment on wood. This study provides valuable insights into regulating the effects of HIMW treatment and expanding its application in wood processing, such as wood drying and functionalized impregnation, according to the specific end-use requirements.

Preparation of a Novel Lignocellulose-Based Aerogel by Partially Dissolving Medulla Tetrapanacis via Ionic Liquid.

A novel lignocellulosic aerogel, MT-LCA, was successfully prepared from MT by undergoing partial dissolution in an ionic liquid, coagulation in water, freezing in liquid nitrogen, and subsequent freeze-drying. The MT-LCA preserves its original honeycomb-like porous structure, and the newly formed micropores contribute to increased porosity and specific surface area. FT-IR analysis reveals that MT, after dissolution and coagulation, experiences no chemical reactions. However, a change in the crystalline structure of cellulose is observed, transitioning from cellulose I to cellulose II. Both MT and MT-LCA demonstrate a quasi-second-order kinetic process during methylene blue adsorption, indicative of chemical adsorption. The Langmuir model proves to be more appropriate for characterizing the methylene blue adsorption process. Both adsorbents exhibit monolayer adsorption, and their effective adsorption sites are uniformly distributed. The higher porosity, nanoscale micropores, and larger pore size in MT-LCA enhance its capillary force, providing efficient directional transport performance. Consequently, the prepared MT-LCA displays exceptional compressive performance and efficient directional transport capabilities, making it well-suited for applications requiring high compressive performance and selective directional transport.

Hierarchically porous cellulose-based carbon aerogels with N-doped skeletons and encapsulated iron-based catalysts for efficient tetracycline catalytic degradation

Three-dimensional interpenetrating and hierarchically porous carbon material is an efficient catalyst support in water remediation and it is still a daunting challenge to establish the relationship between hierarchically porous structure and catalytic degradation performance. Herein, a highly porous silica (SiO2)/cellulose-based carbon aerogel with iron-based catalyst (FexOy) was fabricated by in-situ synthesis, freeze-drying and pyrolysis, where the addition of SiO2 induced the hierarchically porous morphology and three-dimensional interpenetrating sheet-like network with nitrogen doping. The destruction of cellulose crystalline structure by SiO2 and the iron-catalyzed breakdown of glycosidic bonds synergistically facilitated the formation of electron-rich graphite-like carbon skeleton. The unique microstructure is confirmed to be favorable for the diffusion of reactants and electron transport during catalytic process, thus boosting the catalytic degradation performance of carbon aerogels. As a result, the catalytic degradation efficiency of tetracycline under light irradiation by adding only 5 mg of FexOy/SiO2 cellulose carbon aerogels was as high as 90 % within 60 min, demonstrating the synergistic effect of photocatalysis and Fenton reaction. This ingenious structure design provides new insight into the relationship between hierarchically porous structure of carbon aerogels and their catalytic degradation performance, and opens a new avenue to develop cellulose-based carbon aerogel catalysts with efficient catalytic performance.

Dimensions, microstructure, chemical, and hygroscopic analysis of steam-exploded bamboo fibers at different ages

Bamboo fibers (BFs) at different ages (1, 3, and 5 years old) were prepared by pretreatment and steam explosion. The results demonstrated that the separation degrees of BFs increased with the age of the bamboo. The combined effects of pretreatment and steam explosion partially removed the hemicellulose and lignin from BFs, while the crystalline structure of cellulose remained unaltered. The water vapor adsorption isotherms of BFs at different ages all showed a typical S-shape and could be classified as type II, and the hysteresis of BFs increased with the age of the bamboo. After pretreatment and steam explosion, the tissues in the vascular bundle were effectively crushed, and the parenchyma tissues were dislodged and separated from the fiber sheath. During the steam explosion process, hot steam penetrated the bamboo’s pores, including the pores induced by pretreatment. This caused fractures and delamination in the interface between the vascular bundle and the parenchyma tissues. These cracks progressed layer by layer along the vascular bundle interface, leading to the fracture of the bamboo.

Effect of Steam Explosion on the Structure, Chemical Composition and Pyrolytic Volatile Composition of Tobacco Waste

Tobacco stems are an important part of the tobacco leaf, containing a lot of cellulose, result in the low utilization of tobacco leaves in cigarettes. The pre-treatment technology of tobacco stems is a key to increase the utilization of tobacco stems. In this work, steam explosion treatment was carried out on tobacco stems with different moisture contents containing 2%, 5% and 10%, respectively. The steam explosion is carried out under different pressure and pressure holding time conditions, the changes in physical structure, chemical composition and pyrolysis volatiles of tobacco stem was investigated. The results indicate that steam explosion has a negligible impact on the crystalline structure of cellulose and low-order polysaccharide crystals, while it has an obvious effect on KCl. Steam explosion increases the specific surface area by destroying the amorphous structure on tobacco stems. The contents of chemical constituents and pyrolytic volatiles indicate that there is a significant leaching effect of lignin, but no change in cellulose content. Soluble polysaccharides, the main component of hemicellulose, were converted into pyrolytic volatiles e.g., furfural and furfuryl alcohol. In conclusion, the technology of steam explosion promotes the leaching, decomposition and chemical transformation of amorphous structures on tobacco stems, thus destroying the structure of the cell walls.

A novel eco–friendly solid–state degumming method for extraction of hemp fibers

Hemp represents a valuable resource of natural fibers on account of its environment favorable characteristics and excellent fiber quality. To fabricate hemp fibers, the traditional alkaline boiling degumming is used in the industry, which consumes a lot of water and generates a substantial amount of wastewater. In the present study, a novel eco–friendly solid–state degumming method was developed by using ethanolamine (ETA). The ETA degumming exhibited a high lignin removal rate (87.5%) at a high solid loading (30%), decreasing water consumption by 33.3%. Moreover, the ETA solution was readily reused up to five times without purification. The degummed hemp fibers possessed commendable fitness (4.2 dtex) and breaking strength (3.75 cN/dtex) without change of the crystalline cellulose structure. Besides, the lignin in wastewater was confirmed to be aminated, which is beneficial to the potential valorization of the by–product. Thus, the solid–state ETA degumming method holds significant potential for the fabrication of hemp fibers.

The production bioethanol from Ceratophyllum demersum L . in Iraq

Biofuels have attracted a lot of attention due to the growing demand for energy resources and concerns about greenhouse gas emissions. Unlike other green energy resources, biofuels like bioethanol, can provide liquid fuels that is essential for transportation. Second-generation bioethanol can be produced from lignocellulosic biomass through acid hydrolysis and fermentation. Lignocellulosic biomass is widely available and does not affect on the nutritional needs of agricultural crops. In this study, the aquatic plant Ceratophyllum demersum was used. Ceratophyllum demersum is a type of invasive aquatic plant that can live in fresh and brackish waters, and it is abundant in most regions of southern Iraq. The bioethanol with the highest concentration was identified by high-performance liquid chromatography (HPLC). The results showed that 14% of bioethanol was produced in the absence of acid hydrolysis, while the concentration of it increased to 25% with the presence of acid hydrolysis. Acid hydrolysis aims to increase the breaking bonds of lignin and hemicellulose, increase the porosity of the material, and damage the crystalline structure of cellulose, and thus facilitates its conversion to glucose and increases the percentage of ethanol production.

Selectively fractionate hemicelluloses with high molecular weight from poplar thermomechanical pulp by tetramethylammonium hydroxide

Selective fractionation of hemicelluloses is of great significance for realizing high-value application of hemicelluloses and comprehensive utilization of lignocellulosic biomass. Tetramethylammonium hydroxide (TMAH) solvent has been confirmed as a promising solvent to selectively fractionate hemicelluloses from holocellulose. Herein, TMAH solvent was adopted to pretreat poplar thermomechanical pulp (PTMP) for the selective fractionation of hemicelluloses and enhancement of enzymatic hydrolysis performance of residues. The maximal hemicelluloses yield (65.0 %) and excellent cellulose retention rate (93.3 %) were achieved after pretreatment by the 25 wt% TMAH solvent, while the delignification was only 33.9 %. The hemicelluloses fractions could be selectively fractionated with high molecular weights (109,800–118,500 g/mol), the contents of Klason lignin in them were low (3.2–5.9 %), and the dominating structure of them was 4-O-methylglucurono-β-D-xylan. Compared to the H2SO4 and NaOH methods, the hemicelluloses fractionated by TMAH method exhibited higher yields, more complete structures and higher molecular weights. Furthermore, the crystalline structure of cellulose practically remained stable, and the highest yield of enzymatic hydrolysis glucose was 57.5 %, which was 3.3 times of that of PTMP. The fractionation effectiveness of TMAH solvent was not significantly reduced after repeatedly recycling. This work demonstrated TMAH solvent could selectively fractionate hemicelluloses from PTMP and efficiently promote sustainable poplar-based biorefinery.

Effect of Acids and Alkaline Pretreatment of Used Tea Waste Powder under Microwave-Assisted Pretreatment

There are numerous methods to enhance the quality of cellulose for efficient and sustainable fuel production, the acid and alkaline pretreatment methods have become increasingly popular due to their accessibility and affordability. These methods are typically used to eliminate lignin, disrupt the cellulose crystalline structure, and reduce its rigidity. This study focuses on the use of pretreatment with four different types of acids (Hydrochloric Acid, Phosphoric Acid, Acetic Acid, and Sulfuric Acid) and four types of alkaline (Calcium Hydroxide, Sodium hydroxide, Potassium Hydroxide, and Ammonium Hydroxide) were used to soak the used tea waste powder as a raw material under microwave-assisted pretreatment. The effectiveness of acid and alkaline pretreatment methods under microwave heating on used tea waste powder was evaluated through infrared analysis. The experiments were conducted at varying microwave temperatures (100–200 °C), reaction times (2–7 min), and with a 2 g doses of used tea waste powder in 100 mL of diluted acid, and 5% of alkaline solution. The weight loss of liquid and solid samples after acid and alkaline pretreatment under the aid of microwave pretreatment were calculated. FTIR analysis results showed a significant improvement in the characteristics of the treated samples compared to the untreated used tea waste powder.

“Bridging hydrogen bonds” from guanidine and amidoxime groups on natural bamboo strips as a superantibacterial and knitted adsorbent to efficiently adsorb uranium from simulated seawater

Uranium adsorption from seawater can provide a sustainable development path for the future raw material supply of nuclear energy. However, in the process of uranium extraction from seawater, biofouling adheres to the surface of the adsorbent, wasting the adsorption sites and seriously affecting the adsorption capability of the adsorbent. Herein, inspired by the superanti-biofouling property of guanidine groups, a superantibacterial and knitted adsorbent with guanidine and amidoxime groups cografted on natural bamboo strips (G-AOBS) is synthesized to adsorb uranium from simulated seawater. The intrinsic structure of bamboo is not destroyed by the whole grafting process, and G-AOBS still maintains the porous and cellulose crystalline structure. The grafting of guanidine groups improves the hydrophilicity and significantly enhances the anti-biofouling performance, thereby increasing the adsorption capacity for uranium (qe = 201.4 ± 13.23 mg g−1 at pH = 4 with C0 = 100 mg L−1 and qe = 1.04 ± 0.12 mg g−1 in simulated seawater with C0 = 500 μg L−1). According to the results of DFT, the guanidine and amidoxime groups can not only replace one carbonate in uranyl tricarbonate alone to form a more stable coordination structure but also have a synergistic effect between the two, that is, using three “bridging hydrogen bonds” to form the most stable chelation mode with uranyl dicarbonate.

Cellulose microfiber extraction from leftover celery pulp: Chemomechanical treatments, structural, morphological, and thermal characterization

Based on the variety of attractive applicability and structural advantages, cellulose is suggested as a sustainable and environmentally-friendly replacement for petroleum-based materials. Therefore, the current study proposed two chemo-mechanical treatments including bleaching with sodium chlorite and sodium hypochlorite for pure cellulose extraction from leftover celery pulp (Apium graveolens var. dulce). The characterizations of the extracted cellulose fibers were measured and analyzed, by using FT-IR, XRD, optical microscopy, FE-SEM, and TGA analysis. FTIR analysis confirmed the successful removal of non-cellulosic and impurities materials by chemical treatments. Analyzing the X-ray diffraction showed that the proposed chemo-mechanical procedures did not have damaging impacts on the cellulose crystalline structure. Microscopies analysis within optical microscopy and FE-SEM indicated that the diameters of the untreated fibers generally ranged from 100 to 150 μm, while for the treated ones, they ranged from 10 to 15 μm. The TGA results illustrated the higher initial degradation temperatures for the treated samples which led to significant improvement in their thermal stabilities.

Microscopic dissolution process of cellulose in alkaline aqueous solvents and its application in CNFs extraction - Investigating temperature as a variable

The target of this study is to gain a deeper understanding of the micro-dissolution process of cellulose in alkaline aqueous solutions and to develop a novel method for extracting cellulose nanofibrils (CNFs). Herein, the dissolution process of cellulose in alkaline aqueous solutions will be controlled by varying the temperature, and the undissolved cellulose will be analyzed to reveal the microscopic dissolution process of cellulose, and a novel process for extracting cellulose nanofibrils (CNFs) will be developed based on the findings. The crystalline structure of cellulose was gradually disrupted as the dissolution progressed, and the crystal form of cellulose changed gradually from cellulose I to cellulose II during the dissolution process, while all undissolved cellulose crystals remained as cellulose I. Cellulose, after its structure is disrupted during the dissolution process, will inevitably decompose into CNFs, and the microscopic dissolution process of cellulose follows a “top-down” dissolution sequence. The CNFs extraction method developed in this study can extract CNFs with high yield (>60 %) in a stable manner, as well as narrow particle size distribution, high crystallinity (>77 %), and good thermal stability. This study enhances the comprehension of the dissolution process of cellulose and paves a possible way for industrialization of CNFs production.

Utilization of Recycled Egg Carton Pulp for Nitrocellulose as an Accelerant in Briquette Production.

Nitrocellulose (NC) is a conservative material that is used in a variety of applications, such as coating agents, biodegradable plastics, and propellant main charge. Nitrocellulose raw materials are easily obtained from lignocellulose sources, most notably cotton and wood pulp. The egg carton, a recycled paper waste designed for packaging and transporting eggs, is used in this study to make nitrocellulose in pulp form. The effects of different nitration durations (40, 50, and 60 min) from egg carton pulp bleached with various KOH concentrations (0.6 M, 1.0 M, and 1.5 M) on NC properties were evaluated. The accelerant properties of the NC of nitration time in 50 min were studied in a rice husk charcoal briquette. Rice husk charcoal briquettes are made in various ratios with nitrocellulose as an accelerant (97:3, 96:4, and 95:5). The NC was characterized using Fourier transform infrared (IR) spectroscopy and thermogravimetric (TG) analysis. 1.0 M of bleached egg carton pulp has the highest cellulose content (86.94%) with the presence of crystalline structure of cellulose at peak 1430 cm-1 after the bleaching process. Meanwhile, different nitration times revealed that 50 min had the highest nitrogen content (7.97%) with a 1.23 degree of substitution (DS) value. Based on its TG analysis, NC 50 has met the requirements for use as an accelerant for briquettes, with an onset temperature of 91.60 °C and a weight loss of 62.60%. Infrared at peak 1640 cm-1 confirmed the presence of NO2 groups in nitrocellulose successfully formed by nitration. After the addition of nitrocellulose, the calorific value of the briquette increased from 13.54% to 15.47%. Fixed carbon and volatile matter showed the same pattern. The combustion of nitrocellulose-briquette has also been demonstrated by Td10% of degradation, which degraded between 310 and 345 °C.

3D conductive monolithic carbons from pyrolyzed bamboo for microfluidic self-heating system

Bamboo, like wood, is a promising natural template for biobased devices that takes advantage of its hierarchical architecture, microarray channels, anisotropic mechanical and electrical properties. Herein we report a low heat thermal treatment (HTT, 700-1000 °C) of natural bamboo specimens to obtain bamboo-based graphitic devices with thermoelectric and electrochemical properties. The preservation of the highly anisotropic architecture of three-dimensional carbon material (3D-CM) allowed adding specific thermoelectric and electrochemical properties depending on the HTT of the pristine specimens. High electric conductivity (σ, 839 S/m) was observed at 1000 °C showing a remarkable potential application as a bamboo-based working electrode. The bamboo annealed to 700 °C showed higher resistivity (ρ, 0.15 Ω m, and σ, 6.6 S/m), thermal conductivity (1.77 W/m K), and thermal heating rate (1.0 °C/s). The pyrolyzed biomass (B-700) was used as a 3D microfluidic heater to heat polar solvents (H2O and ethylene glycol) in flow mode up to their boiling points. A 2D carbon hotplate heater was built-up to warm solvent in batch mode. A complete chemical and physical characterization of the samples allowed us to determine structural and chemical compositions, cellulose crystalline structure phase transition to graphitic/turbostratic carbon, thermal and electrical conductivity of unprecedented bambootronics bio-devices.

Kinetic studies on photo-degradation of thermally-treated spruce wood during natural weathering: Surface performance, lignin and cellulose crystallinity

The hygroscopic behavior of wood-based materials is undoubtedly influential on the material surfaces exposed to climatic conditions. The paper aims to kinetically investigate the photo-degradation and surface characteristics of thermally-treated spruce wood at 185 °C and un-treated (reference) sample through 2 years of natural weathering. Attenuated Total Reflectance Fourier Transform Infrared (ATR-FTIR) spectroscopy and X-ray diffraction (XRD) were employed to investigate the chemical changes occurred in lignin and crystalline structure of cellulose as a function of outdoor exposure. Detailed measurements of morphological and surface changes were evaluated during exposing periods. Surface wettability and roughness as well as cracks were increased for all samples due to weathering as the exposure time extended. Prominently, the color changes (ΔE) and photo-chemical reactions were found to be negligible in short-time weathering thanks to thermal modification. In the long–term exposing, more OH-bonds caused by lignin leaching out resulted in presence of cracks and the affinity for water on reference sample. Degree of crystallinity significantly decreased by 12.7% in thermally treated wood and 18.3% in reference sample after long-term weathering while, the crystallinity index of thermally-treated wood increased to 4.7% in 6-month weathering. Hence, the amorphous structures and chromophores groups appeared on the reference wood at a faster and more intense rate during exposing time. Thermal treatment delayed photo-yellowing as well as color change of wood due to up-graded lignin and cellulose crystallinity through a photo-stable structure. Accordingly, kinetic studies ascertained the service-time of wood products in exterior uses.

Generation of microcrystalline cellulose from cotton waste and its properties

Microcrystalline cellulose (MCC) is a green material that has widespread applications in pharmaceuticals, food, cosmetics, and other industries because of its biocompatibility, biodegradability, hydrophilicity, and acid-insolubility. In this study, MCC was prepared from cotton waste via alkaline treatment and sulfuric acid hydrolysis. Further, the synthesized cotton-based MCC was characterized using Fourier transform infrared (FTIR), X-ray photoelectron, and energy dispersive X-ray spectroscopies. Based on these results, the major components were identified as carbon and oxygen. This finding was evidenced by the FTIR analysis, which displayed peak wavenumbers at 3446.9, 2891.1, 1649.5, 1380.1, 1061.2, and 1050 to 1150 cm-1. The surface morphology was also examined by field emission scanning electron microscopy and field emission transmission electron microscopy, which showed that the prepared MCC has a smooth surface and a consistent, rod-like shape. In addition, the MCC exhibited the typical diffraction peaks of a crystalline structure of cellulose II at 12.2°, 20°, and 22.03°, which correspond to the diffraction planes of 1-10, 110, and 020, respectively, and had a crystallinity index of 78.7%. Moreover, the prepared MCC had a diameter of 37.8 µm and exhibited good stability with a peak at -76.5 mV. Further, the cotton-based MCC exhibited high thermal stability, as revealed by the TGA.

Characterization of Cellulose Fibers According to Cellulase-Active Microbial Pretreatment

This study evaluated the effects of microbial (Bacillus subtilis, Bacillus licheniformis) pretreatment and mechanical (ball mill) treatment on the nanofibrillation of cellulose. The optimal growth conditions were identified a B. subtilis (pH 6-8, 25℃ and 100 rpm) and B. licheniformis (pH 7, 35℃ and 150 rpm), respectively. As a result of evaluating microbial reducing sugar production from carboxymethyl cellulose, B. subtilis case showed similar trends at most experimental conditions (pH, temperature and rpm) except for pH 5. The maximum amount of reducing sugar by B. licheniformis was achieved at the culture conditions with pH 7, 35℃ and 150 rpm. There was no change in the crystalline structure of cellulose by ball mill and microbial treatment, but, XRD peaks intensity decreased. Cellulose nanofibers were observed after 6 hours ball mill treatment of alpha cellulose with/without the microbial pretreatment. When applying microbial pretreatment, the cellulose nanofibers produced by the ball mill had more longer in length than those without the pretreatment.

Influences on the accuracy of crystallinities determined by the method of Ruland and Vonk

X-ray diffractometry is the method of choice for the determination of crystallinities in non-thermoplastic polymers, prominently in cellulose. Obtaining quantitative measures on a sound theoretical basis includes the integration of intensities scattered by the crystalline phase over volume elements in reciprocal space. This is hampered by the occurrence of diffuse scattering, whose profile is not readily distinguishable from scattering by amorphous phases. The manner of evaluating diffractograms pioneered by Ruland and refined by Vonk allows to determine crystallinities by integrating only the coherently scattered portion of crystalline-phase intensities and extrapolating their proportion to a scattering vector of 0. However, preferred crystallite orientations within measured samples, as well as the range of scattering vectors from which the data are extrapolated, have been pointed out as sources of systematic error. We investigated the influence of these factors at the examples of two crystalline structures of cellulose and two types of technically relevant thermoplastics. We found that the method of Ruland and Vonk is rather robust when applied to cellulose, but decidedly less so when applied to polymers with highly symmetric crystalline phases. We also found that there is a range of scattering vectors that leads systematically to the most accurate measures of crystallinity. We further investigated the influence of the crystallite sizes, the crystallinities themselves and the thermal displacement factors, and found that the latter had a profound effect on the accuracies of determined crystallinities.

The Effect of Cellulose Crystalline Structure Modification on Glucose Production from Chemical-Composition-Controlled Biomass

The crystalline structure is a biomass recalcitrance factor that hinders chemical or biological access to degrade the plant cell-wall structure. However, controversy persists over whether a ratio of the crystalline region, the crystallinity index, is a critical biomass recalcitrance factor. In this study, an alkaline treatment modified from mercerization was adopted to alleviate the crystalline structure in the xylem of eucalyptus, along with hemicellulose and lignin removal via autohydrolysis and acid–chlorite treatment, respectively. Then, the glucose yield of the treated solid residues was used as a parameter of biomass recalcitrance. The alkaline treatment successfully reduced the crystallinity index, and the maximal reduction ratio was 84.9% when using an 8% sodium hydroxide solution. However, the reduction ratio of the crystallinity index was dependent on the remaining lignin content in the treated solid residues. Additionally, the lignin removal ratio showed critical influence to improve the glucose yield that was even observed in the treated solid residue having a low reduction ratio of the crystallinity index. Consequently, the cellulose crystalline structure is minimally involved with biomass recalcitrance, especially cellulase activity, at least in eucalyptus.