Search

In recent times, the investigation and development of multifunctional textiles have become a necessity for the textile and apparel industries. Therefore, this paper explores an innovative approach to enhancing the functional properties of cotton (cellulosic) fabric by integrating advanced technologies to impart oleophobic/hydrophobic, flame-retardant, and antibacterial characteristics. The methodology involves systematically applying chemical treatments utilizing a layer-by-layer finishing technique to achieve the desired multifunctionality in cotton fabric. Silver nanoparticles and a phosphorus-nitrogen-based synergistic flame-retarding agent were employed to finish the fabric. Performance testing encompasses evaluating bacterial reduction, contact angle measurements, water absorption properties, flame-retardant capabilities, and Limiting Oxygen Index (LOI). Characterization techniques such as FTIR, SEM, and EDX analysis, were carried out to assess structural and chemical modifications of the material. The results illustrate a notable transformation of the cellulosic fabric, showcasing enhanced resistance to bacterial attack, improved stain resistance, and heightened flame-retardant performance, without compromising its color indices and air permeability. The fabric retains these multifunctional attributes even after 20 cycles of laundering, which confers durability. The implications of this research extend the application of conventional cotton fabric in diverse sectors, including apparel, home furnishings, and industrial textiles. [ABSTRACT FROM AUTHOR]

Flax reinforced epoxy (F-Ep) composites were prepared by the compression moulding technique, varying the fiber content (0, 25, 35 and 45 wt%). The free vibration test was performed on the neat epoxy and F-Ep composites to understand their dynamic characteristics, and results showed that natural frequency and damping factor of the F-Ep composites increased with an increase in the fiber content. The F-Ep composite (45F-Ep) that exhibited better damping was selected for performing the drilling operation. Factors such as spindle speed (rpm), feed rate (mm/min) and drill point angle (degree) were chosen as input parameters and the tabulated set of experiments were in accordance with Taguchi's design of experiment. The response measured was thrust force and the obtained values were found in the range of 19.66 to 50.75 N. The minimum value of thrust force was achieved when the F-Ep composite was drilled at high spindle speed (3000 rpm), with a feed rate of 75 mm/min using the drill point angle of 118°. ANOVA analysis showed that the developed regression model was significant and thrust force was mainly influenced by the spindle speed. Mathematical models were developed for drilling F-Ep composite using response surface methodology (RSM) and adaptive neuro fuzzy inference system (ANFIS) and compared for their efficacy. [ABSTRACT FROM AUTHOR]

In this experimental study, the usability of waste corn husk was investigated as a source of reinforcement material for the first time in eco-friendly particleboard manufacture. For this purpose, the effect of the most appropriate filler/binder (f/b) ratio and pressing temperature manufacturing conditions on three-point flexural strength in particleboard manufacture was examined. To improve the mechanical properties, the water resistance and combustion resistance of the manufactured particleboards, different amounts of corn silk fiber (0~1.50% by weight) and waste colemanite (0~20% by weight) were added. According to the experimental results, the most appropriate manufacturing conditions for the manufacture of corn husk-based particleboard were determined as f/b ratio of 0.75, pressing temperature of 100 °C, and corn silk fiber loading of 0.75 wt%. Additionally, synthetic binders and beet molasses were used together in particleboard manufacture. The particleboards manufactured comply with the specifications of the EN 312 standard, being below the maximum limit values in terms of thickness swelling, and water absorption rates. In addition, by increasing the waste colemanite content in the board composition, the limiting oxygen index (LOI) values and combustion resistance of the boards were increased. However, the use of waste colemanite in particleboard manufacture reduced the flexural strength of the boards. When 5% waste colemanite was added to the particleboards, the boards manufactured met the minimum limit value requirement for P1 type board, according to EN 312. The dimensional stability of the manufactured particleboards, according to the determined manufacturing conditions, is quite good. Particleboards manufactured from corn husks can be used in interior and exterior applications as ecofriendly building materials. [ABSTRACT FROM AUTHOR]

In recent years, the applications of lignocellulosic biomass (LCB) have substantially increased due to its versatility in different areas of study and interest. Therefore, it is evident that the delignification pretreatment of LCB is fundamental to assure the viability and commercial quality of the final product for different industrial uses. The efficiency of delignification, the obtainment of the desired products, and the required quality depend mainly on the type of pretreatment and the method used. This paper presents a state-of-the-art overview of physical, chemical, organic, biological, hybrid (combination of two or more pretreatments), and other novel pretreatments for the delignification of different lignocellulosic biomass. Additionally, the conditions necessary for the application of the pretreatments, the effect of the variables involved, and the advantages and disadvantages of each method are discussed. Finally, advances in the development of sustainable methods are discussed. [ABSTRACT FROM AUTHOR]

BACKGROUND: The exploration of a robust solid acid catalyst for the efficient hydrolysis of cellulose is a research hotspot due to the need for clean production and sustainable development. KIT‐6 silica offers abundant three‐dimensionally interconnected mesopores, which are expected to be superior to mesoporous structures with one‐ or two‐dimensional channels due to faster diffusion of reactants and products during reaction. The catalytic conversion of microcrystalline cellulose is examined in detail over a functionalized KIT‐6 catalyst prepared by the method of Zr addition and subsequent sulfation. RESULTS: In terms of cellulose conversion and product yield, the activity of the catalysts followed the order of sulfated Zr‐KIT‐6 > Zr‐KIT‐6 > SO42−‐KIT‐6 > KIT‐6. Over the sulfated Zr‐KIT‐6 catalyst with a Si/Zr molar ratio of 7:1, a maximum cellulose conversion of 95.0% was achieved with glucose yield of 23.4%, 5‐hydroxymethylfufural yield of 4.9% and levulinic acid yield of 11.7% under the optimized reaction conditions: reaction temperature of 200 °C, reaction time of 2 h, catalyst amount of 0.3 g, cellulose‐to‐water mass ratio of 1:1. CONCLUSION: The sulfated Zr‐KIT‐6 catalyst possessed the strongest and richest Brønsted acid sites, which readily provided protons for the cleavage of β‐1,4 glycosidic bonds in cellulose, thus conferring superior catalytic activity in cellulose hydrolysis. A plausible pathway at the initial stage of cellulose hydrolysis over the catalyst was proposed. © 2023 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

There has been continuous interest in developing novel activators that facilitate the functionalization of cellulosic materials. In this paper, we developed a strategy in which trisubstituted triazinium salts act as cellulose preactivators. As leaving groups, these triazinium salts utilize N-heterocycles (pyridine, imidazole, and nicotinic acid). Initially, we optimized the synthetic route for developing these novel cellulose preactivators (triazinium salts), whose structures were confirmed using NMR spectroscopy. The surface zeta potential of cellulose changed from a negative value to a positive one after preactivation due to the cationic nature of these preactivators. To enhance the scope of the study, we functionalized the cellulose-preactivated materials with a series of amine- or hydroxy-containing aliphatic and aromatic hydrocarbons, nucleophilic amino acids (cysteine), colorants (2-aminoanthraquinone and 2-amino-3-methyl-anthraquinone), and biopolymer (zein protein). The treated samples were analyzed using FTIR, time-gated Raman spectroscopy, and reflection spectroscopy, and the success of the functionalization process was validated. To widen the scope of such chemistries, we synthesized four reactive agents containing N-heterocyclic-based leaving groups (pyridine and nicotinic acid) and successfully functionalized cellulose with them in one step. The proposed single- and two-step functionalization approaches will provide opportunities for chemically linking various chemical compounds to cellulose for different applications. [ABSTRACT FROM AUTHOR]

β-Irradiation ("e-beaming") as well as swelling in ionic liquids, each process by itself, are common pretreatments in biorefinery scenarios. A combination of both, such as occurs with β-irradiation of biomass that was insufficiently washed and still contains traces of ionic liquids, causes covalent derivatization of the contained cellulose and incorporation of nitrogen. The nitrogen uptake occurred only in the presence of the ionic liquid and correlated linearly with both the irradiation dose and the concentration of the contained ionic liquid. The presence of other wood constituents during β-irradiation decreased nitrogen uptake, but did not prevent it. The derivatization of cellulose did not depend on the degree of crystallinity, but appeared to depend on the content of oxidized groups (carbonyl functionalities), also with a linear correlation. Future work must now clarify the mechanism of this reaction and the influence of other wood constituents, and address the possible potential of e-beaming in the presence of imidazolium ionic liquids for cellulose chemistry. [ABSTRACT FROM AUTHOR]

Along with the increased usage of cellulose in the manufacture of novel materials, those of its derivatives that have good solubility in water or organic solvents have become increasingly important. In this study, hydroxypropyl cellulose (HPC), a cellulosic derivative with distinct features, was utilized to investigate how two of the most-selective oxidation methods currently available in the literature act on the constituent OH groups of both the side chain and the anhydroglycosidic unit in HPC. The oxidation reactions were carried out first using TEMPO, sodium hypochlorite, and sodium bromide, then sodium periodate (NaIO4), for 5 h. A combination of these two protocols was applied. The amount of aldehyde and number of carboxylic groups introduced after oxidation was determined, while the changes in the morphological features of oxidized HPC were, additionally, assessed. Furthermore, utilizing Fourier-transform infrared spectra, X-ray diffraction, and thermogravimetric studies, the chemical structure, crystallinity, and thermal stability of the oxidized HPC samples were examined and compared. [ABSTRACT FROM AUTHOR]

This article explores an easy and economically viable route for cellulose fibre isolation from the stem of Pennisetum polystachion and its utility as reinforcement filler in the polymer matrix for the development of biocomposites. The cellulose fibre was isolated by alkali treatment, followed by chlorine free bleaching using hydrogen peroxide. The SEM and FTIR analyses revealed removal of hemicelluloses and lignin. The X-ray diffraction analysis showed increased crystallinity and the TGA and DTG curves indicated greater thermal stability of the isolated fibre compared to the raw fibre. The cellulose fibre was used as reinforcement in ethylene propylene diene monomer (EPDM) rubber to prepare biocomposites. The cure characteristics and mechanical properties of the composites were investigated. The maximum torque and the mechanical properties varied by the addition of the filler in the matrix. The SEM images of the composites showed good adhesion of the cellulose fiber in the EPDM matrix. The biodegradability of the composites was confirmed by the soil burial test. The test revealed that the percentage degradation in tensile strength increased with filler loading, indicating that the composites are environmentally friendly and biodegradable. [ABSTRACT FROM AUTHOR]

Quality attributes of tissue products establish important differentials in the current scenario of fierce competition. Although the formation of the tissue paper is not monitored in industrial processes, it is imperative to recognize its importance for developing quality properties. A theoretical analysis of influences of the fiber morphology and furnish composition on the prediction of mass distribution uniformity in the paper forming process is presented. The theory utilizes the Poisson distribution for the grammage probability of points on the sheet, taken as a random fibrous network. The simulations revealed that lower grammage coefficients of variation could be achieved with total or predominant addition of eucalyptus fibers in mixtures with Pinusfibers. The results provide meaningful insights into the understanding of how the selection of fiber type and pulp blend could help in achieving suitable structural uniformity of the sheet, in the forming process, in view of the expected paper quality. [ABSTRACT FROM AUTHOR]

This study explores the synthesis and characterization of cellulose acetate/zeolite (CA/Ze) fibers as effective adsorbents for the removal of Pb2+ and Cu2+ ions from aqueous solutions. Cellulose acetate was derived from sugarcane bagasse (SCB) and integrated with zeolite to create CA/Ze fibers. Characterization techniques, including FTIR spectroscopy and SEM analyses, confirmed the successful modification and incorporation of zeolite within the fiber structure. Hydration studies revealed the fibers’ stability in water, while adsorption experiments examined factors affecting adsorption capacity, such as pH, time, initial concentration, and reuse. The Langmuir and Freundlich isothermal models were applied to analyze adsorption isotherms. The results demonstrated the potential of CA/Ze fibers for efficient heavy metal removal, with a maximum adsorption capacity for Pb2+ ions of 13.9 mg/g. While the adsorption efficiency decreased after regeneration cycles, CA/Ze fibers displayed promise as sustainable adsorbents. This research contributes to addressing heavy metal pollution while promoting eco-friendly waste utilization. [ABSTRACT FROM AUTHOR]

Cellulose fibers have attracted interest as a suitable candidate for manufacturing composites. In the present work, cellulose derived from waste pistachio shell was used to prepare composite membranes with poly(ethylene-co-vinyl acetate (EVA) via solution casting, and their morphological, mechanical, organic vapour permeation characteristics and biodegradability were evaluated. Scanning electron micrographs showed that the voids in the EVA polymer were filled effectively by cellulose fibers. The mechanical testing of the composites revealed an improvement in Young’s modulus with the increase in cellulose loading. The permeation of polar and non-polar solvents through the membranes was studied and explained by molar size, molecular mass and polarity of the solvents. Nielson’s permeability equation as modified by Baradwaj was used to analyse the relative permeability of the membranes. Soil burial degradation experiments of the composite membranes showed a decrease in weight and tensile strength, revealing the biodegradability of the membranes. [ABSTRACT FROM AUTHOR]

In this study, structural and morphological characterizations were carried out to evaluate the integration, distribution and degradation of sugarcane bagasse fiber (CBF) in a concrete matrix. The samples for evaluation were modified by adding CBF in 0.5% and 1% wt proportions. The modified concrete specimens were exposed to different aggressive conditions over four years before use. The chemical and structural properties of the modified samples were evaluated using Fourier transform infrared spectroscopy, X-ray diffraction and X-ray photoelectron spectroscopy, while the morphology, distribution and fiber degradation in the samples were determined using scanning electron microscopy and confocal laser scanning microscopy, respectively. The results obtained from spectroscopy and X-ray diffraction indicated the presence of cellulose, and showed a change in molecular orientation, which was attributed to the hydrolysis reaction. The microscopy analyses revealed that the CBF did not undergo degradation. [ABSTRACT FROM AUTHOR]

Over the years, the preparation method chosen for the preparation of cellulose reinforced nylon or polyamide (PA) composites has proven to be critical in determining the overall properties of the composites. For example, melt processing of cellulose reinforced nylon or PA composites presents challenges, such as (i) irreversible hornification of cellulose material upon drying, before melt processing; (ii) non-uniform dispersion or distribution of cellulose in the polymer matrix; (iii) thermal degradation of cellulose at elevated temperatures and (iv) structural integrity (fibrillation) and shortening of cellulose upon mechanical shearing during melt processing. All these challenges have the potential to compromise the overall properties of the prepared composites. In order to circumvent these challenges, several techniques have been used. For example, hornification, can be overcome by using a technique called wet feeding. Thermal degradation can be overcome by coating cellulose materials via either chemical or physical wrapping with a macromolecule or surfactant. The thermal degradation of cellulose can also be prevented by using in situ polymerization of PA via the ring opening polymerization technique during the manufacture of cellulose reinforced nylon composites, as well as solvent casting in formic acid/water mixtures. The incorporation of up to 50 wt% cellulose nanofibers (CNFs) in PA nanocomposites via solvent casting improved elastic modulus by 64% and tensile strength by 62%. The aim of this manuscript is to review preparation techniques of low cost, high strength composites using cellulose fibers and engineering plastics like polyamides (PAs, nylons). [ABSTRACT FROM AUTHOR]

Paddy straw is often burnt in the fields or disposed of in ways that cause extensive environmental pollution. The present study focused on using paddy straw in bio-compostable composites fabricated with polyvinyl alcohol (PVA) and thermoplastic starch blends as a matrix. Locally available paddy straw was chopped, cleaned and treated with 15% NaOH solution for four hours. The alkali treatment produced changes in the crystal structure and surface morphology of the paddy straw. Then, it was dispersed in blends of PVA and starch solutions containing polyethylene glycol (PEG200) as plasticizer. The PEG200 acted as both plasticizer and compatibilizer, as evidenced by the single glass transition peak and the lower melting point of the film cast from these blends. These composite films had higher thermal stability, increased tensile strength, but also flexibility. These properties were associated with structure development with strong hydrogen bonding interaction between the paddy straw and PVA-starch blends, which was supported by results of characterization studies. [ABSTRACT FROM AUTHOR]

Food packaging is intended to protect food and extend its shelf life, but it may affect food quality and safety because of chemical migration. Food quality and safety regarding packaging is a significant global concern. Legislations have an essential role in providing regulatory guidance on quality assurance systems and verifying their implementation as a means of regulatory compliance. The large number of various materials used in the manufacture of packages complicates the evaluation of food–packaging interactions. This review is an overview of literature data on the effects of printed food packaging on the migration of chemicals into foods, as well as on various migration sources of chemical compounds. Various aspects, such as the interaction between packaging and food starting with the production process of food packaging to food–packaging contact during storage, the effects of primary and secondary packaging on chemical migration, permeability of packaging materials, ink-induced migration in printed packaging, and types of transition from packaging to food, were examined in detail. Besides, studies on subjects such as the food contact materials analysis used to test the phenomenon of migration in foods and migration limits have been discussed. Moreover, studies on the use of recycled paper in packaging and its effect on migration, ink chemicals resulting from recycling and studies on this subject are included. Information is given on measures to reduce the effect of migration, low migration of printing inks, coatings and adhesives, and materials used in barrier applications. In line with this research study, suggestions were made for measures to reduce the harmful effects of chemical migration on human health and to prevent the risk of migration from packaging to food. [ABSTRACT FROM AUTHOR]

Wet wipes are good examples of common textile materials used in daily life. Although they can serve for different purposes, wet wipes for personal hygiene are especially popular, in particular, those with antimicrobial properties. Considering their demand, especially during epidemics, it is expected that the wet wipe market has the potential to expand further. In order to achieve antibacterial properties, wet wipes contain various chemicals, some of which can have a negative impact on human health. By using natural substances, it is aimed to minimize the use of harmful substances in wet wipes and offer innovative products on the market. For this, in the present study, leaf extract and fruit juice from gilaburu plants (Viburnum opulus L.) were used. The solutions obtained were used directly, without the addition of any further chemicals, in the impregnation of nonwoven webs/fabrics. Then, the impregnated nonwoven webs (wet wipes) were analyzed in terms of antibacterial properties and storage stability. The obtained results showed that the wipes (nonwoven webs) impregnated with gilaburu fruit juice could decrease Escherichia coli and Staphylococcus aureus bacteria populations even after 5 weeks of storage. [ABSTRACT FROM AUTHOR]

Papyrus (Cyperus papyrus L.) is a lignocellulosic plant suitable for many applications when properly pretreated. This study explores the potential of a two-stage pretreatment (combining hydrothermal and chemical methods) on the characteristics of cellulose fibers derived from papyrus. One-stage and two-stage pretreatments were compared, utilizing sodium hydroxide (NaOH) and ferric chloride (FeCl3) chemical solutions at a 3% (w/v) concentration. Chemical pretreatment was employed for one-stage processing, while hydrothermal pretreatment was introduced prior to chemical pretreatment. As the liquid hot-water process intensified, significant changes in chemical composition and morphology occurred. Hydrothermal pretreatment partially eliminates hemicelluloses and lignin, while increasing the cellulose content and enhancing fiber crystallinity. Following the pulping and bleaching stages, it was determined that the FeCl3-based two-stage pretreatment exhibited the greatest potential for cellulose recovery and hemicelluloses and lignin removal, yielding the highest crystallinity index. [ABSTRACT FROM AUTHOR]

Hepatocellular carcinoma (HCC) is a fatal malignancy with a poor prognosis. There is an urgent need to study the molecular mechanisms of HCC development and explore potential drugs to improve survival. This study aims to investigate the antitumor effects of astaxanthin on HCC proliferation, migration, invasion and apoptosis through regulation of adenosine-activated protein kinase (AMPK). CCK8, wound healing, transwell and flow cytometry assays were used to evaluate Hep 3B cell viability, migration, invasion and apoptosis after astaxanthin treatment. Protein expression was determined by Western blot. CCK8 assays showed that all concentrations (200 μM, 400 μM, 500 μM) of astaxanthin used in this study significantly inhibited the proliferation of Hep 3B cells (P < 0.05). Wound healing, transwell and flow cytometry showed that astaxanthin inhibited Hep 3B cell migration and invasion and induced apoptosis. Western blot showed that astaxanthin increased the expression of p-AMPK (P <0.05) and inhibited its downstream p-mTOR protein expression (P < 0.05). The effects of astaxanthin on cell proliferation, migration, invasion and apoptosis was attenuated after addition of the AMPK blocker Compound C. To conclude, astaxanthin inhibits the proliferation, migration and invasion of HCC by regulating AMPK, and promotes tumor cell apoptosis in a dose-dependent manner. [ABSTRACT FROM AUTHOR]

Efficient and cost-effective conversion of lignocellulosic biomass into usable forms of energy presents unique challenges. Lignocellulosic biomass, comprising cellulose, hemicelluloses, and lignin, necessitates advanced conversion technologies. Common commercial delignification techniques, including kraft pulping, sulfite pulping, acid hydrolysis, and organosolv pulping, often involve harsh conditions leading to structural changes in lignin and environmental impacts. To address these issues, acid hydrotropes have emerged as a promising method for lignin extraction. Acid hydrotropes, represented by p-toluenesulfonic acid (p-TsOH), enable the solubilization of hydrophobic substances like lignin. This mini-review provides an overview of various lignocellulose fractionation techniques and explores the acid hydrotrope approach. The mechanism behind acid hydrotropic fractionation is discussed, and its performance is evaluated. In conclusion, the review emphasizes the pivotal role of the acid hydrotrope approach in advancing lignocellulosic biomass conversion technology, promoting a sustainable and efficient bio-based economy [ABSTRACT FROM AUTHOR]

In this study, cellulose fiber was extracted from bamboo shoot shell with a deep eutectic solvent (DES). The deep eutectic solvent used was prepared by the fusion of choline chloride (ChCl), oxalic acid (OA) and ethylene glycol (EG) at 80 °C. Based on the degumming rate, the influence of temperature and time on the DES degumming system was determined. Based on the scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and thermogravimetric analysis (TG) results, it was confirmed that the DES system can remove colloids from bamboo shoot shell, increasing the thermal stability and heat resistance of bamboo shoot shell fiber, and improving its crystallinity. It was proved that the DES system can effectively remove lignin and hemicelluloses, and retain cellulose in bamboo shoot shell. [ABSTRACT FROM AUTHOR]

The present study deals with the green synthesis of silver nanoparticles (Ag NPs) using a chemically modified polysaccharide as a reducing and capping agent. Dextran succinate (Dex-Suc) was synthesized by succinylation of the dextran with succinic anhydride at 80 °C for 24 h under stirring and N2. The Dex-Suc was used as a reducing and capping agent for the synthesis of Ag NPs in the presence of sunlight with high UV index. The Ag NPs were characterized using UV-Vis spectroscopy, SEM, and EDS techniques. The SEM data revealed the preparation of spherical Ag NPs having 50 nm size. The Ag NPs showed antimicrobial properties against different bacterial and fungal strains. [ABSTRACT FROM AUTHOR]

Xylan is a polysaccharide found in plant cell walls. It is considered to be a biodegradable polymer, which does not affect negatively the environment. Sulfated xylan derivatives exhibit valuable bioactive properties, in particular, anticoagulant and hypolipidemic. We report on the development of a new method for sulfation of birch wood xylan. Activators of the sulfation reaction with sulfamic acid have been evaluated. Numerical methods have been used to establish the optimum process parameters that ensure the maximum sulfur content in the reaction product. The incorporation of a sulfate group has been confirmed by infrared and nuclear magnetic resonance spectroscopy, and elemental analysis. The initial and sulfated xylans have been comprehensively studied by theoretical methods and the most favorable conformations of the initial xylan and its sulfate have been established. [ABSTRACT FROM AUTHOR]

In this study, pine needles were exploited for bioethanol production. Pretreatment is the first and foremost step towards better yield of bioethanol from lignocellulosic biomass. In this study, NaOH pretreatment of pine needles was optimized by the Box Behnken design. Substrate characterization was done by using X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). Maximum cellulose (90%) and total phenolic compounds (51.03 ± 0.002 mM) were recorded under optimized conditions, and structural analysis also revealed the significance of the pretreatment. High F and R2 values and low P values indicated the accuracy and validity of the model. Pretreated biomass was further subjected to saccharification using commercial, as well as indigenous cellulase. Maximum saccharification (49.2%) was observed with commercial cellulase, which led to a 7% ethanol yield employing Saccharomyces cerevisiae. Maximum ethanol yield (7%) was observed in NaOH pretreated biomass. Results proposed that Pinus spp. needles could be potential cellulosic biomass for bioethanol production. [ABSTRACT FROM AUTHOR]

Agricultural waste leads to a number of environmental issues, including pollution and environmental degradation. In Nigeria, Zea mays husk is one of the most prevalent agricultural wastes, and it can be turned into a valuable resource of quality cellulose. The goal of this study was to establish a low-cost and sustainable chemical treatment method for isolating cellulose from Z. mays husk feedstock. A series of alkaline delignification, digesting, and bleaching techniques were used to extract and purify cellulose. TAPPI T203 OS-74, TAPPI T222 OS-83 and TAPPI T222 OM02 methods were used to determine the cellulose, hemicellulose and lignin contents, respectively. The samples were also characterised by scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy (FTIR), and CHNS/O analyses. The resulting product was found to contain 97.95% α-cellulose, 0.19% β-cellulose, and 1.86% γ-cellulose. The presence of 40.95% carbon, 2.98% hydrogen, 0.72% nitrogen, 0.07% sulphur, and 55.28% oxygen was found by the CHNS/O analysis of cellulose. The untreated husk microscopy displayed an uneven, flake-like, and nonuniform surface, whereas the delignified husk, digested husk, and pure cellulose (ZMH-C) micrographs revealed, respectively, a smooth non-uniform surface, an irregular porous surface, and a smooth wool-like surface. The FTIR spectra of the treated samples demonstrated an increase in the intensity of the polar property of the OH group, as well as the elimination of the hemiacetal group and β-1,4-glycosidic linkages. The ZMH-C diffractogram verified the existence of characteristic 2θ peaks of cellulose at 220, 240, and 300, as well as a 4.7% crystallinity index. The comparatively low-temperature sequential alkaline delignification, digesting, and bleaching method adopted extracted low-lignin crystalline cellulose material from Z. mays husk. The flexibility, biodegradability, and availability of husk make it a viable source of high-quality cellulose with several possible applications. Z. mays cellulose has been thus demonstrated to be an appealing material for a wide variety of industries seeking environmentally acceptable and sustainable solutions. [ABSTRACT FROM AUTHOR]

In recent years, there has been a persistent search for new methods and technologies for cultivating specific crops to increase their productivity and improve product quality. The aim of the study was to obtain essential oil from poplar buds by the barothermal method, to standardize the obtained essential oil, to study the effect of an aqueous emulsion of poplar oil on the growth and development of tomato seeds. For obtaining the maximum yield of balsam poplar essential oil, the optimum pressure, input of raw material, and processing time were investigated. The essential poplar oil was standardized according to organoleptic and physico-chemical parameters. The study found that the use of an aqueous emulsion of poplar bud oil had a significant impact on the morphogenesis, physiological and biochemical parameters of tomato seeds. [ABSTRACT FROM AUTHOR]

The incorporation of TEMPO-oxidized cellulose nanofibers (TOCNs) derived from wood pulp resulted in an improvement in the characteristics of polymeric membranes made up of poly (methyl vinyl ether maleic acid)/PMVEMA and poly (ethylene glycol)/PEG. The membranes were constructed, and TOCNs were included in the formulation at a rate of 5 wt%. TOCNs were categorized as either short or long, depending on the aspect ratio measurement. According to the findings of the research, the various lengths of TOCNs resulted in variances in the optical transmittance properties, contact angles, and whiteness level of the membranes, in addition to a little variation in the tensile and thermal properties of the material. When compared to short TOCNs, long TOCNs offer somewhat improved performance in terms of optical transmittance, whiteness level, tensile characteristics, and thermal stability. The results of this study reveal the significance of the morphology of nanocellulose in determining the properties of the composite that includes it. Thus, the characteristics of the target membrane were greatly influenced by nanocellulose morphology. [ABSTRACT FROM AUTHOR]

The alteration of mechanical properties because of moisture is an inevitable problem in the practical use of cellulosic materials, as well as green and high-performance materials synthesized based on cellulose. Although researchers have analyzed and reported this issue from various aspects, it is necessary to report the variation of mechanical properties of the cellulose system and its causes in detail from the molecular level as well. Herein, the effect of moisture content on the mechanical properties of cellulose is methodically examined by molecular dynamics methods. The main reasons for the structural changes caused by the stiffness and activity space of the cellulose chains and the number of hydrogen bonds in the system are explained and discussed. The obtained results reveal that, in the simulated range of moisture content, low moisture (0 to 4%) exhibits a positive effect on the mechanical properties of the amorphous cellulose region, whereas the effect of high moisture content (4 to 8%) is negative. The mobility of cellulose chains first reduces and then intensifies as the number of water molecules increases, while the rigidity of the corresponding system first increases and then decreases. Additionally, the free volume of the system increases first and then decreases as the number of water molecules rises. The mechanical properties of the amorphous region of cellulose are proportionally correlated with the number of hydrogen bonds in the system. Based on these results, a moisture content of 2% can enhance the properties, increasing the H-bond density in the cellulose network. [ABSTRACT FROM AUTHOR]

Borohydride reduction of dialdehyde cellulose (DAC) is a promising strategy to generate dialcohol cellulose as bio-based alternative to petroleum-based materials. However, the degradation of the polymer backbone according to β-elimination mechanisms limits the practical applications of the reaction. Therefore, we aimed at optimizing the process to suppress degradation reactions by varying reaction time, pH, and reagent stoichiometry. The degree of oxidation (DO) of the DAC intermediates significantly impacts the yields and molecular weights of the isolated dialcohol celluloses, with a "leveling-off" effect at higher DO values. Increasing the amount of sodium borohydride can minimize—but not entirely prevent—chain scissions. Lowering the pH value during reduction slows down the degradation but results in incomplete conversion of the aldehyde functionalities. Our study provides valuable insights into the consequences of side reactions during borohydride reduction of DAC as well as into chemistry and analysis of the dialdehyde cellulose/dialcohol cellulose system. About a dilemma in cellulose chemistry: Dialcohol cellulose derived by periodate oxidation and subsequent borohydride reduction of cellulose has received increasing attention in the development of sustainable thermoplastic materials. The present study highlights the challenge of suppressing β-elimination and favoring the reduction pathway to optimize reaction conditions and minimize chain degradation. [ABSTRACT FROM AUTHOR]

Ionic liquids (ILs) are the only media that can allow the homogeneous organocatalytic reactions of lignocellulosic biomass (lignocellulose), since the designability of their cations and anions offers the dual functions of solubility and catalytic activity. This review provides an account of our recent achievements in the organocatalytic approaches for converting lignocellulose into polymer materials based on the principles of IL design that we have originally established. These methodologies include the simple and mild chemical modification of cellulose and lignin under high conversions, with high selectivity, and/or with efficient atom economy. Similar reactions and subsequent fractionation processes are applied to lignocellulose, and a highly productive reaction system is developed using a twin‐screw extruder that is specific to the IL media. [ABSTRACT FROM AUTHOR]

This document, titled "Recent Advances in Cellulose Chemistry," discusses the transition from fossil-based raw materials to biomass-based materials and their applications in sustainable chemical industries. It highlights the use of cellulose, a renewable and abundant biopolymer, in various domains and technologies such as coatings, films, membranes, building materials, and pharmaceuticals. The document features six contributions, including research articles and a review article, that explore different aspects of cellulose chemistry. These contributions cover topics such as the synthesis of cellulose nanocomposites with antimicrobial properties, the use of cellulose as a catalyst support, the fabrication of cellulose-based composite films, and the manufacturing of cellulose pulp using organosolvent methods. Overall, cellulose holds significant potential for both expanding knowledge in the field and industrial applications. [Extracted from the article]

In the history of cellulose chemistry, hydrogen bonding has been the predominant explanation when discussing intermolecular interactions between cellulose polymers. This is the general consensus in scholarly textbooks and in many research articles, and it applies to several other biomacromolecules' interactions as well. This rather unbalanced description of cellulose has likely impacted the development of materials based on the processing of cellulose—for example, via dissolution in various solvent systems and regeneration into solid materials, such as films and fibers, and even traditional wood fiber handling and papermaking. In this review, we take as a starting point the questioning of the general description of the nature of cellulose and cellulose interactions initiated by Professor Björn Lindman, based on generic physicochemical reasoning about surfactants and polymers. This dispute, which became known as "the Lindman hypothesis", highlights the importance of hydrophobic interactions in cellulose systems and that cellulose is an amphiphilic polymer. This paper elaborates on Björn Lindman's contribution to the subject, which has caused the scientific community to revisit cellulose and reconsider certain phenomena from other perspectives. [ABSTRACT FROM AUTHOR]

Fibrous nanofluidic materials are ideal building blocks for implantable electrode, biomimetic actuator, and wearable electronics due to their favorable features of intrinsic flexibility and unidirectional ion transport. However, the large-scale preparation of fibrous nanofluidic materials with desirable mechanical strength and good environment adaptability for practical use remains challenging. Herein, by fully taking advantage of the attractive mechanical, structural, and chemical features of boron nitride (BN) nanosheet and nanofibrillated cellulose (NFC), a scalable and cost-effective three-dimensional (3D) printed macrofiber featuring abundant vertically aligned nanofluidic channels is demonstrated to exhibit a good combination of high tensile strength of 100 MPa, thermal stability of up to 230 °C, and ionic conductivity of 1.8 × 10−4 S/cm at low salt concentrations (< 10−3 M). In addition, the versatile surface chemistry of cellulose allows us to stabilize the macrofiber at the molecular level via a facile post-cross-linking method, which eventually enables the stable operation of the modified macrofiber in various extreme environments such as strong acidic, strong alkaline, and high temperature. We believe this work implies a promising guideline for designing and manufacturing fibrous nanodevices towards extreme environment operations. [ABSTRACT FROM AUTHOR]

Studying the surface chemistry of functionalized cellulose nanofibrils at atomic scale is an ongoing challenge, mainly because FT-IR, NMR, XPS and RAMAN spectroscopy are limited in sensitivity or resolution. Herein, we show that dynamic nuclear polarization (DNP) enhanced 13C and 15N solid-state NMR is a uniquely suited technique to optimize the drug loading on nanocellulose using aqueous heterogenous chemistry. We compare the efficiency of two conventional coupling agents (DMTMM vs EDC/NHS) to bind a complex prodrug of ciprofloxacin designed for controlled drug release. Besides quantifying the drug grafting, we also evidence the challenge to control the concurrent prodrug adsorption and to optimize washing procedures. We notably highlight the presence of an unexpected prodrug cleavage mechanism triggered by carboxylates at the surface of the cellulose nanofibrils. Functionalized nanocellulose is a promising drug carrier, however, studying surface functionalization at the atomic scale remains challenging due to spectroscopic methodology limitations. Here, the authors use dynamic nuclear polarization enhanced 13C and 15N solid-state NMR to optimize the drug loading on nanocellulose using aqueous heterogeneous chemistry. [ABSTRACT FROM AUTHOR]

Aiming to increase the scarce information available on the kinetics of cellulose dissolution, we have applied an image-assisted technique based on the luminance evolution as cellulose dissolves to study this process under different experimental conditions. This protocol was validated via direct determination of the cellulose dissolved. In all cases datapoints were linearly fitted assuming a pseudo-zero order reaction which facilitates the comparison between datasets. To study the solvent effect we have used three ionic liquids with large basicity and found significantly different rates of dissolution, from faster to slower: [C 2 C 1 Im][OAc]>[C 1 C 1 Im][DMP]>[C 2 C 1 Im][DEP]. Solvatochromic parameters and viscosity of the solvent media were determined and the latter was identified as a key factor slowing the process as it reduces ionic mobility. The weight of viscosity was estimated by removing the viscosity effect with a tuned solvent media doped with DMSO. Activation energy was 70% lower at constant viscosity. On the substrate side, particle size is the main factor affecting the dissolution rate. All samples were milled to homogenise the starting material and minimise the distortions caused by the size distribution. After, dissolution of three cellulose substrates under the same experimental conditions was analysed. Dissolution of natural fibers took twice as long as dissolving pulp which dissolves slower than lyocell fibers. This trend correlates with the roughness of the samples obtained by optical perfilometry which is consistent with the dissolution mechanism proposed in the literature. [ABSTRACT FROM AUTHOR]

The preparation and performance control of the cellulose membrane are one of the hot topics in the environmentally friendly separation membrane field. In this study, microcrystalline cellulose (MCC) was prepared by microwave-assisted acidic hydrolysis of cellulose obtained from jute, followed by the use of a mixture of N-methylmorpholine-N-oxide and water as a solvent to obtain the homogeneous casting liquid, which was scraped and subsequently immersed in the coagulation bath to form a smooth and dense cellulose membrane. During membrane formation, the crystal structure of MCC changed from type I to type II, but the chemical structure remained unchanged. The mechanical strength and separation performance of the membrane were related to the content of MCC in the casting liquid. When the content of MCC was about 7%, the tensile strength of the membrane reached a maximum value of 13.49 MPa, and the corresponding elongation at break was 68.12%. The water flux (J) and rejection rate (R) for the bovine serum albumin were 19.51 L/(m2·h) and 95.37%, respectively, under an optimized pressure of 0.2 MPa. In addition, the coagulation bath had a significant effect on the membrane separation performance, and J and R were positively and negatively correlated with the polarity of the coagulation bath. Among them, it was note-worthy that J and R of membrane formed in ethanol were 33.95 L/(m2·h) and 91.43%, separately. Compared with water as a coagulation bath, J was increased by 74% at the situation and R was roughly equivalent, showing better separation performance. More importantly, the relationship between the structure and separation performances has also been studied preliminarily. This work provides certain guidance for the preparation of high-performance MCC membranes. [ABSTRACT FROM AUTHOR]

There has been continuous interest in developing novel activators that facilitate the functionalization of cellulosic materials. In this paper, we developed a strategy in which trisubstituted triazinium salts act as cellulose preactivators. As leaving groups, these triazinium salts utilize N-heterocycles (pyridine, imidazole, and nicotinic acid). Initially, we optimized the synthetic route for developing these novel cellulose preactivators (triazinium salts), whose structures were confirmed using NMR spectroscopy. The surface zeta potential of cellulose changed from a negative value to a positive one after preactivation due to the cationic nature of these preactivators. To enhance the scope of the study, we functionalized the cellulose-preactivated materials with a series of amine- or hydroxy-containing aliphatic and aromatic hydrocarbons, nucleophilic amino acids (cysteine), colorants (2-aminoanthraquinone and 2-amino-3-methyl-anthraquinone), and biopolymer (zein protein). The treated samples were analyzed using FTIR, time-gated Raman spectroscopy, and reflection spectroscopy, and the success of the functionalization process was validated. To widen the scope of such chemistries, we synthesized four reactive agents containing N-heterocyclic-based leaving groups (pyridine and nicotinic acid) and successfully functionalized cellulose with them in one step. The proposed single- and two-step functionalization approaches will provide opportunities for chemically linking various chemical compounds to cellulose for different applications.

Metal nanoparticles have been widely used for catalysis because of its excellent catalytic activity and selectivity. Green and sustainable supports play a quite important role in the enhancement of the efficiency and recyclability of metal nanoparticles. Here, a cellulose/β-cyclodextrin hydrogel is applied to support tannic acid-encapsulated metal (such as Ag, Au, Pd and Cu) nanoparticles to generate nanocomposite hydrogels for catalysis. TEM analysis indicates that these metal nanoparticles have the average diameters of 6.5 nm for Au nanoparticles, 7.0 nm for Ag nanoparticles, 5.0 nm for Pd nanoparticles and 4.0 nm for Cu nanoparticles, respectively. The catalytic activities of the as-prepared metal nanocomposite hydrogels are estimated in a series of chemical reactions in the aqueous system. The recyclability, applicability and generality of these nanocomposite hydrogels are also well investigated. The nanocomposite hydrogels can be reused for at least 10 times in the 4-nitrophenol reduction, 8 times for Suzuki–Miyaura coupling reaction and 6 times for click reaction, respectively. Furthermore, good yields are obtained in the catalytic process. This study gives a green and sustainable strategy to support metal nanoparticles with good catalytic activity and recyclability. [ABSTRACT FROM AUTHOR]

In order to protect the environment and cellulose resources, yarn wastes from the textile industry, which contains a considerable amount of cellulose, can be used to produce microcrystalline cellulose. In this study, yarn waste was milled via a ball mill and was subjected to acid hydrolysis using sulfuric acid and hydrochloric acid at different times. It was characterized through various tests to determine the particle size, degree of polymerization, bulk and tap density, water soluble substances, ash content, moisture absorption capacity, infrared spectroscopy, X-ray diffraction, and thermogravimetric analysis. The Fourier-transform infrared spectroscopy analysis showed that the chemical compositions of all the samples were the same. The X-ray diffraction measurement showed an increase in crystallinity after acid hydrolysis. The thermogravimetric analysis showed that prepared microcrystalline cellulose via acid hydrolysis had good temperature resistance. The results obtained showed that the cotton waste from textiles was able to produce cellulose microcrystalline at a pharmacy standard level. [ABSTRACT FROM AUTHOR]

The ternary phase diagram based on cellulose (cellulose polymer/mixed solvents/Water (non-solvent)) system has been measured at 30 °C for two sources of cellulose. Cellulose synthesized from fibers of cotton and olive significantly influences the behavior of the crystallization index, which can cause changes during the film formation process. The differences can be explained by the presence of amorphous areas linked to a higher disorder, which is highlighted by the X-ray diffraction analysis XRD (crystallinity rate was 15.6% versus 47.4% for acetylated cellulose). The experimental analysis was carried out on the coexisting phases and the determination of binodal curve. The cellulose film was formed based on the equilibrium diagram to control the structure, which showed some dependence between the composition data and the binary interaction parameters in order to achieve liquid–liquid phase separation. This system required a large amount of water (15–90 wt.% water) to affect the porous and fibrous structure of the film. Olive cellulose films with lower crystallinity have smaller diameter (38 nm), they can swells faster and their solubility increases more, unlike acetate cellulose (56 nm). It can be said that the solvent diffusion is greater in the amorphous domains due to their higher disorder resulting in easy accessibility. [ABSTRACT FROM AUTHOR]

In this work, by loading a chromium Salen complex on amino-functionalized cellulose (AFC-SalenCr), a novel and efficient heterogeneous catalyst was successfully synthesized, and used for the copolymerization of sulfur dioxide (SO2) with cyclohexene oxide for the first time. The catalysts were characterized by FTIR, XPS, ICP-MS and TGA for their physiochemical and thermal properties. The as-prepared AFC-SalenCr showed high catalytic activity for the copolymerization. Under optimal reaction conditions, the molecular weight of the resultant copolymer could reach 40,100 g/mol. Moreover, the catalyst was able to recover facilely and be reused for four cycles without any significant activity loss. In addition, the thermal degradation kinetics of the synthesized copolymer was further studied using Kissinger and Flynn–Wall–Ozawa methods for the first time, which indicated that the activation energy of the thermal degradation was 92.8 kJ/mol and 94.0 kJ/mol, respectively. [ABSTRACT FROM AUTHOR]

Guanidine-based surfactant ethyl lauroyl arginate (LAE) and cellulose nanocrystals (CNCs) form complexes of enhanced surface activity when compared to pure surfactants. The LAE-CNC mixtures show enhanced foaming properties. The dynamic thin-film balance technique (DTFB) was used to study the morphology, drainage and rupture of LAE-CNC thin liquid films under constant driving pressure. A total of three concentrations of surfactant and the corresponding mixtures of LAE with sulfated (sCNC) and carboxylated (cCNC) cellulose nanocrystals were studied. The sCNC and cCNC suspension with LAE formed thin films, with stability increasing with surfactant concentration and with complex rheological properties. In the presence of LAE, the aggregation of CNC was observed. While the sCNC aggregates were preferentially present in the film volume with a small fraction at the surface, the cCNC aggregates, due to their higher hydrophobicity, were preferentially located at film interfaces, forming compact layers. The presence of both types of aggregates decreased the stability of the thin liquid film compared to the one for the LAE solution with the same concentration. The addition of CNC to LAE was critical for foam formation, and foam stability was in qualitative agreement with the thin films' lifetimes. The foam volume increased with the LAE concentration. However, there was an optimum surfactant concentration to achieve stable foam. In particular, the very resistant foam was obtained with cCNC suspensions that formed the interfaces with a complex structure and rheology. On the other hand, at high LAE concentrations, the aggregates of CNC may exhibit antifoaming properties [ABSTRACT FROM AUTHOR]

Cellulose-based materials have attracted great attention due to the demand for eco-friendly materials and renewable energy alternatives. An increase in the use of these materials is expected in the coming years due to progressive decline in the supply of petrochemicals. Based on the limitations of cellulose in terms of dissolution/processing, and focused on green chemistry, new cellulose production techniques are emerging, such as dissolution and functionalization in ionic liquids which are known as green solvents. This review summarizes the recent ionic liquids used in processing cellulose, including pretreatment, hydrolysis, functionalization, and conversion into bio-based platform chemicals. The recent literatures investigating the progress that ILs have made in their transition from academia to commercial application of cellulosic biomass are also reviewed. [ABSTRACT FROM AUTHOR]

Cellulose with numerous hydroxyl groups and electronegative atoms can form extensive hydrogen bonds, which are non-negligible obstacles to its dissolution and further utilization. Herein, an in-depth understanding of the interactions between solvent and cellulose, including binding energy, Gibbs free energy, and reaction rate constant, was pursued to screen for appropriate hydrogen bond donor–acceptor couples to form a new type of metal salt hydrate-based eutectic solvent that functions as molecular scissors to dissolve cellulose at room temperature. The optimal solvent exhibits a strong hydrogen bond accepting ability that is capable of breaking the strong hydrogen bonds within cellulose, and thus can spontaneously and efficiently dissolve various types of cellulose, with clear advantages of low cost, environmental friendliness, simple operation, energy efficiency, scalable productivity, and recyclability. [ABSTRACT FROM AUTHOR]

Reacting with reductive phenolic hydroxyls (–OH) and methoxy groups (–OCH3) on lignin, silver ions (Ag+) were reduced to metallic silver nanoparticles (NPs) with sizes smaller than 40 nm. The resulting Ag/lignin NPs were then physically crosslinked in the cellulose hydrogel, followed by freeze-drying to obtain the final Ag/lignin NP-loaded cellulose aerogel. Loaded with Ag/lignin NPs, the aerogel exhibited strengthened mechanical property (387 ± 11 kPa) against the external deformation at a compressive strain of 65% due to the nano-reinforcement by the loaded Ag/lignin NPs when compared with pure cellulose aerogel (246 ± 32 kPa). The Ag/lignin NP-loaded aerogel also showed robust killing efficiency against different pathogenic bacteria in aqueous solution (Escherichia coli: > 99.99%, Pseudomonas aeruginosa: > 99.9%, Vibrio cholera: > 99.99%, Staphylococcus aureus: > 99.99%, Bacillus subtilis: > 97.4%). Moreover, the loaded Ag/lignin NPs provided the aerogel with excellent catalytic degradation ability toward various organic compounds, including dyes, pollutants, and antibiotics, evidenced by the degradation of methylene blue (99.8% in 30 min) and methyl orange (99.9% in 180 min) in the presence of NaBH4 and natural sunlight radiation, and degradation of rhodamine B (99.9% in 35 min), 4-nitrophenol (99.5% in 180 min) and doxycycline hyclate (99.8% in 30 min) in the presence of NaBH4 without natural sunlight. In addition, the Ag/lignin NP-loaded aerogel could be reused after facile regeneration washing with water while retaining excellent performance on efficiently degrading (~ 100%) the organic dyes for at least three cycles. The roles of loaded Ag/lignin NPs as photoelectron generators and relay centers for transferring electrons from the reductant to the targeted organic compounds during the degradation process were comprehensively investigated and explained. [ABSTRACT FROM AUTHOR]

Bacterial cellulose ionogels (BCIGs) represent a new class of material comprising a significant content of entrapped ionic liquid (IL) within a porous network formed from crystalline cellulose microfibrils. BCIGs suggest unique opportunities in separations, optically active materials, solid electrolytes, and drug delivery due to the fact that they can contain as much as 99% of an IL phase by weight, coupled with an inherent flexibility, high optical transparency, and the ability to control ionogel cross-sectional shape and size. To allow for the tailoring of BCIGs for a multitude of applications, it is necessary to better understand the underlying principles of the mesoscopic confinement within these ionogels. Toward this, we present a study of the structural, relaxation, and diffusional properties of the ILs, 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([emim][Tf2N]) and 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide ([bmpy][Tf2N]), using 1H and 19F NMR T1 relaxation times, rotational correlation times, and diffusion ordered spectroscopy (DOSY) diffusion coefficients, accompanied by molecular dynamics (MD) simulations. We observed that the cation methyl groups in both ILs were primary points of interaction with the cellulose chains and, while the pore size in cellulose is rather large, [emim]+ diffusion was slowed by ∼2-fold, whereas [Tf2N]− diffusion was unencumbered by incorporation in the ionogel. While MD simulations of [bmpy][Tf2N] confinement at the interface showed a diffusion coefficient decrease roughly 3-fold compared to the bulk liquid, DOSY measurements did not reveal any significant changes in diffusion. This suggests that the [bmpy][Tf2N] alkyl chains dominate diffusion through formation of apolar domains. This is in contrast to [emim][Tf2N] where delocalized charge appears to preclude apolar domain formation, allowing interfacial effects to be manifested at a longer range in [emim][Tf2N]. [ABSTRACT FROM AUTHOR]

Polyisocyanate was used to chemically functionalize carboxylated cellulose nanofibers (CNF‐C). Composites of CNF‐C/ monomer casting nylon (MC nylon) and modified CNF‐C/MC nylon were fabricated by anionic ring‐opening polymerization. The mechanical characteristics of the MC nylon composites and the dispersion of the CNF‐C in the MC nylon were studied. The tensile strength and impact strength of composites were first increased with CNF‐C addition, but then decreased as further CNF‐C was added. The composites had good mechanical properties when CNF‐C was added to MC nylon at 1.0 wt%, and the tensile strength and impact strength were increased by 21.2% and 34.9%, respectively, compared to MC nylon. When modified CNF‐C was added at 1.5 wt%, the tensile strength of composites was increased by 47.90%. The addition of CNF‐C causes an increase in the melting point, crystallinity, and crystallization temperature, which was confirmed by differential scanning calorimetry (DSC). The modified CNF‐C had better dispersibility in MC nylon which was confirmed by scanning electron microscopy (SEM). [ABSTRACT FROM AUTHOR]

A phosphate flame-retardant hardener (PFH) produced on the basis of industrial orthophosphoric acid and acetic anhydride was proposed for reducing the combustibility and revealing the natural texture of wood. Under fire conditions, phosphorus-containing compounds are able to decompose with formation of polyphosphoric acids providing a barrier coating on the combustion surface, as well as of substances inhibiting free-radical combustion, thereby reducing the rate of combustion and heat release. Wood surface treatment with the PFH was shown to reveal the natural texture of wood as a result of the reactions between the hydrolysis products of cellulose with the lignin components by the mechanism operating in the formation of triphenylmethane dyes. It was demonstrated that specifically the phenolic components of lignin participate in the formation of colored compounds, since cellulose with 90% lignin removed and cotton roving are not colored by the PFH. Softwoods are colored more strongly than hardwoods because of a higher lignin content. A complete scheme of reactions responsible for the appearance of colored structures in the wood texture in the presence of the PFH and atmospheric oxygen was proposed. A mechanism of thermal decomposition of cellulose during combustion in the presence of the PFH, resulting in predominant formation of a carbonaceous residue, was considered. From the quantitative data provided by the experiments on burning Whatman filter papers impregnated with the PFH, catalysis of the coke formation and enhancement of the coke yield were inferred. It was concluded that treatment with the PFH provides decorative appearance to wood and produces a protective effect thereon via reducing combustibility. A system of transparent decorative fire-resistant wood finishing was proposed, in which the PFH performs the function of a flame retardant and Porenbeize, and as well as of a hardener for epoxy varnish finish coating. [ABSTRACT FROM AUTHOR]

Organic solvents with low Henry's constants, such as propylene carbonate (PC) and sulfolane, were proposed to be used as CO2 absorbents to increase CO2 absorption capacity in the CO2 switchable solvent, so that the dissolution of cellulose can be effectively enhanced. With the addition of PC, the maximum concentration achieved for the dissolution of paper cellulose can be largely increased from 1.0 to 5.0 wt%, while those for microcrystalline cellulose and corncob cellulose were increased from 5.0 to 10.0 and 7.0 wt%, respectively. Moreover, the chemical and crystalline structure of the regenerated cellulose was not affected by the addition of CO2 absorbents. This study illustrated a simple and effective way to modify the CO2 switchable solvent, which would be helpful for the application of the complex solvent system for the enhanced dissolution, derivatization, and processing of cellulose in the future. [ABSTRACT FROM AUTHOR]

The transition to a bioeconomy is attracting the use of wood powders for developing bio-based chemicals, fuels, and products to replace fossil-based products. Wood powder-based products depend on the properties and quality of wood powders. Despite many studies on their morphological and physical properties, studies on micromorphology and extractive micro-distribution are scarce. Here we investigated the effect of milling type and wood quality in terms of moisture content on microstructural changes and native extractive distribution in wood powders. The findings showed that non-dried and dried multi-blade shaft mill (MBSM) powders had smooth surfaces and less undamaged cellulosic fibre walls, and extractives were located in the cell lumen. Non-dried and dried hammer mill powders had a rough surface and fibres with structural deformations in their cell walls (e.g. dislocations). Extractives were redistributed on the particle surface as well as dispersed in the cell lumen for both types of hammer mill powders. In a word, the powders obtained from MBSM technology are more native in structure. The findings of the study can have implications for downstream processes., (© 2024. The Author(s).)