Crystalline structure analysis of cellulose treated with sodium hydroxide and carbon dioxide by means of X-ray diffraction and FTIR spectroscopy

Study of the effect of bleaching agents on the crystalline index of cellulose-based materials derived from corn husk by CP/MAS 13C NMR and FT-IR spectroscopies

This work proposes an evaluation of the Crystalline Index (CrI) in function of the bleaching process employed during cellulose extraction from corn husk, for further characterization using CP/MAS 13C NMR, XRD, and FT-IR. In that sense, CrI values were calculated by FT-IR and the bands associated with the crystalline and amorphous regions were observed at 1424 cm-1 and 896 cm-1, respectively. Similarly, the signals due to ordered (89.1 ppm) and disordered (84.2 ppm) cellulose chains were detected by solid-state 13C NMR, while the Segal equation was only used for comparison purposes. Additionally, PCA studies showed consistent results attributed to the crystalline region in cellulose domains analyzed by both, FT-IR and solid-state 13C NMR. The results revealed the coexistence of cellulose I/cellulose II and its effect on CrI, as well as the incomplete mercerization process, in some cases non-cellulosic residues can cause an overestimation of CrI. Additionally, the thermal stability and the glass transition temperature were determined by TGA/DTA and DSC analyses. Finally, a partially fibrillated-network morphology with a diameter of 20.47 ± 2.77 μm was observed in cellulose bleached with peracetic acid, whereas organosolv method provides flexible and clean microfibrils with diameter sizes between 10 and 9 μm.

Demystifying the tropics: FTIR characterization of pantropical woods and their α-cellulose extracts for past atmospheric 14C reconstructions

To ensure unbiased tree-ring radiocarbon (14C) results, traditional pretreatments carefully isolate wood cellulose from extractives using organic solvents, among other chemicals. The addition of solvents is laborious, time-consuming, and can increase the risk of carbon contamination. Tropical woods show a high diversity in wood-anatomical and extractive composition, but the necessity of organic-solvent extraction for the 14C dating of these diverse woods remains untested. We applied a chemical treatment that excludes the solvent step on the wood of 8 tropical tree species sampled in South-America and Africa, with different wood-anatomical and extractive properties. We analyzed the success of the extractive removal along with several steps of the α-cellulose extraction procedure using Fourier Transform Infrared (FTIR) spectroscopy and further confirmed the quality of 14C measurements after extraction. The α-cellulose extracts obtained here showed FTIR-spectra free of signals from various extractives and the 14C results on these samples showed reliable results. The chemical method evaluated reduces the technical complexity required to prepare α-cellulose samples for 14C dating, and therefore can bolster global atmospheric 14C applications, especially in the tropics.

Nanocellulose-alginate composite beads for improving Ciprofloxacin bioavailability

Nanocellulose is a potential material utilized in numerous biomedical applications. However, its hydrophilic characteristic and uncontrolled encapsulated drug release hinders nanocellulose uses in oral drug administration. Thus, this work developed novel nanocellulose/alginate composite (CNC/Alg) beads for oral delivery and bioavailability enhancement of a model drug, Ciprofloxacin (CIP). CNC was green synthesized employing electrolysis process from sugarcane bagasse. CNC/Alg beads were formulated by dropwise adding CNC-Alg mixture in CaCl2 solution at room temperature. CIP was incorporated into CNC/Alg beads by adsorption technique. X-ray diffractometry and Fourier-transform infrared spectra images showed that the beads were effectively produced with high crystallinity of 75.5 %, and the typical bond of cellulose and alginate. Within 4 h of adsorption, CIP loading efficiency reached 45.27 %, with 87.2 % molecules in the zwitterionic state. The adsorption followed Elovich and pseudo-second-order models, indicating a multi-mechanism including both physical and chemical adsorptions. Importantly, in gastrointestinal tract, the beads could protect CIP from acidic stomach environment while releasing it sustainably in simulated intestinal condition (75.05 %). The beads also showed strong antibacterial activity against both Gram(-) and Gram(+) bacteria, as evidenced by low IC50 and minimum inhibitory concentration values. Finally, CNC/Alg beads could improve CIP bioavailability for effective oral drug delivery route.

Effects of Ultrasonication in Water and Isopropyl Alcohol on High-Crystalline Cellulose: A Fourier Transform Infrared Spectrometry and X-ray Diffraction Investigation

This paper investigates the effects of ultrasonication on cellulose microparticles in different conditions. FTIR (Fourier transformed infrared spectrometry) and XRD (X-ray diffraction) analyses were used to compare the changes in the cellulose microstructure caused by the following various ultrasonic treatment conditions: time, amplitude of generated ultrasound waves, output power converted into ultrasound, the liquid medium (water and isopropyl alcohol) used for ultrasonication, and the shape of the vessel used for sonication. The cumulative results lead to an increase in the crystalline region directly proportional to the condition of sonication. Also, the total crystallinity index varied from 1.39 (pristine cellulose) to 1.94 for sonication in alcohol to 0.56 for sonication in water. The crystallinity index varied from 67% (cellulose) to 77% for the sample with 15 min of sonication in isopropyl alcohol and 50.4% for the sample with 15 min of sonication in water.

A solar-driven nanocellulose Janus aerogel with excellent floating stability and dual functions of oil-water separation and photocatalytic degradation of organic pollutants

Effective and practical cleanup of viscous crude oil spills is extremely important in real harsh marine environments. Herein, we designed a solar-driven, nanocellulose-based Janus aerogel (Janus-A) with excellent floating stability and dual function of oil-water separation and degradation of aqueous organic pollutants. Janus-A, with its amphiprotic nature, was prepared through polypyrrole (PPy) deposition, freeze-drying, octyltrichlorosilane (OTS) impregnation, TiO2 spraying on the bottom surface, and UV irradiation treatment. The photothermal conversion effect of PPy coating raised the surface temperature of aerogel to 75.8 °C within 6 min under one simulated solar irradiation, which greatly reduced the viscosity of the crude oil and increased the absorption capacity of the aerogel to 36.7 g/g. Benefiting from the balance between the buoyancy generated by the hydrophobic part and water absorption of the hydrophilic part, Janus-A showed excellent floating stability under simulated winds and waves. In addition, Janus-A exhibited high degradation efficiency for organic pollutants in water owing to the synergistic photocatalytic properties of TiO2 and PPy. These excellent performances make Janus-A ideal for integrated water-oil separation and water remediation.

Comparison of Seed Morphology and Seed Coat Chemistry in Ophrys (Orchidaceae) Species

Orchidaceae is the largest flowering plant family in the world and holds significant importance in terms of biological diversity. Many of the species are found in endemic regions, serving as important indicators for the conservation of biological diversity. Therefore, research on the morphology, seed and embryo structures, chemical composition, and taxonomy of orchids is crucial for species conservation, habitat restoration, and the sustainability of natural habitats. This research involves comparing the morphometric and chemical contents of seeds belonging to certain Ophrys L. species and examining interspecies relationships. The micromorphological features of the seeds were analyzed by using light microscopy and scanning electron microscopy (SEM), while their chemical contents were compared by using Fourier transform infrared spectroscopy (FT-IR) analysis. Seed and embryo morphology, morphometric analysis, and seed coat chemistry hold diagnostic significance. In species of the Ophrys genus, features like anticlinal wall structure and periclinal wall reticulation are considered weak taxonomic characters. FT-IR analysis identifies specific chemical groups in orchid samples, revealing significant differences in absorbance values and chemical compositions among the different orchid species. Particularly, Ophrys lycia (Lycian Kaş Orchid) shows distinct separation from closely related species at peak points such as 2917 and 2850, 1743, 1515, 1240, and 1031 cm-1. Common peak points in the fingerprint region (1200- 700 cm-1) indicate similarity between O. apifera and O. reinholdii subsp. reinholdii. O. ferrum-equinum, O. mammosa subsp. mammosa, O. fusca subsp. leucadica, O. reinholdii subsp. reinholdii, and O. iricolor exhibit similar absorbance values in the range of 1500-1000 cm-1. These results provide valuable preliminary information about the structure of orchid seed coats, reticulation presence and pattern, chemical profiles, distribution, and dormancy-germination processes.

Action of AA9 lytic polysaccharide monooxygenase enzymes on different cellulose allomorphs

Lytic polysaccharide monooxygenase (LPMO)-catalyzed oxidative processes play a major role in natural biomass conversion. Despite their oxidative cleavage at the surface of polysaccharides, understanding of their mode of action, and the impact of structural patterns of the cellulose fiber on LPMO activity is still not fully understood. In this work, we investigated the action of two different LPMOs from Podospora anserina on celluloses showing different structural patterns. For this purpose, we prepared cellulose II and cellulose III allomorphs from cellulose I cotton linters, as well as amorphous cellulose. LPMO action was monitored in terms of surface morphology, molar mass changes and monosaccharide profile. Both PaLPMO9E and PaLPMO9H were active on the different cellulose allomorphs (I, II and III), and on amorphous cellulose (PASC) whereas they displayed a different behavior, with a higher molar mass decrease observed for cellulose I. Overall, the pretreatment with LPMO enzymes clearly increased the accessibility of all types of cellulose, which was quantified by the higher carboxylate content after carboxymethylation reaction on LPMO-pretreated celluloses. This work gives more insight into the action of LPMOs as a tool for deconstructing lignocellulosic biomass to obtain new bio-based building blocks.

Linear and nonlinear regression modelling of industrial dye adsorption using nanocellulose@chitosan nanocomposite beads

Nanocellulose@chitosan (nc@ch) composite beads were prepared via coagulation technique for the elimination of malachite green dye from aqueous solution. As malachite green dye is highly used in textile industries for dyeing purpose which after usage shows fatal effects to the ecosystems and human beings also. In this study the formulated nanocellulose@chitosan composite beads were characterized by Particle size analysis (PSA), Field emission scanning electron microscopy (FESEM), Fourier-transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analysis were done to evaluate nanoparticles size distribution, morphological behaviour, functional group entities and degree of crystallinity of prepared beads. The nanocomposite beads adsorption performance was investigated for malachite green (MG) dye and BET analysis were also recorded to know about porous behaviour of the nanocomposite beads. Maximum removal of malachite green (MG) dye was found to be 72.0 mg/g for 100 ppm initial dye concentration. For accurate observations linear and non-linear modelling was done to know about the best-fitted adsorption model during the removal mechanism of dye molecules, on evaluating it has been observed that Langmuir isotherm and Freundlich isotherm show best-fitted observation in the case of linear and non-linear isotherm respectively (R2 = 0.96 & R2 = 0.957). In the case of kinetic linear models, the data was well fitted with pseudo-second-order showing chemosorption mechanism (R2 = 0.999), and in the case of non-linear kinetic model pseudo first order showed good fit showing physisorption mechanism during adsorption (R2 = 0.999). The thermodynamic study showed positive values for ΔH° and ΔS° throughout the adsorption process respectively, implying an endothermic behaviour. In view of cost effectiveness, desorption or regeneration study was done and it was showed that after the 5th cycle, the removal tendency had decreased from 48 to 38 % for 20-100 ppm dye solution accordingly. Thus, nanocomposite beads prepared by the coagulation method seem to be a suitable candidate for dye removal from synthetic wastewater and may have potential to be used in small scale textile industries for real wastewater treatment.

High-barrier, flexible, hydrophobic, and biodegradable cellulose-based films prepared by ascorbic acid regeneration and low temperature plasma technologies

Regenerated cellulose (RC) films are considered a sustainable packaging material that can replace non-degradable petroleum-based plastics. However, their susceptibility to water vapor and oxygen can limit their effectiveness in protecting products. This study introduces a novel approach for enhancing RC films to create durable, flexible, hydrophobic, high-barrier, and biodegradable packaging materials. By exploring the impact of ascorbic acid coagulation bath treatment and plasma-enhanced chemical vapor deposition (PECVD) on the properties of RC films, we found that the coagulation bath treatment facilitated the organized reconfiguration of cellulose chains, while PECVD applied a dense SiOx coating on the film surface. The results demonstrated a significant enhancement in water vapor and oxygen barrier properties of the composite film, almost reaching the level of commercial barrier films. Moreover, the composite film displayed exceptional biodegradability, fully degrading in soil within 35 days. Additionally, it showcased impressive mechanical strength, hydrophobic characteristics, and freshness preservation, positioning it as a valuable option for bio-based high-barrier packaging applications.

The development of an innovative method to improve the dissolution performance of rivaroxaban

Recent advancements in the formulation of solid dosage forms involving active ingredient-cyclodextrin complexes have garnered considerable attention in pharmaceutical research. While previous studies predominantly focused on incorporating these complexes into solid states, issues regarding incomplete inclusion prompted the exploration of novel methods. In this study, we aimed to develop an innovative approach to integrate liquid-state drug-cyclodextrin inclusion complexes into solid dosage forms. Our investigation centered on rivaroxaban, a hydrophobic compound practically insoluble in water, included in hydroxypropyl-β-cyclodextrin at a 1:1 M ratio, and maintained in a liquid state. To enhance viscosity, hydroxypropyl-cellulose (2 % w/w) was introduced, and the resulting dispersion was sprayed onto the surface of cellulose pellets (CELLETS®780) using a Caleva Mini Coater. The process parameters were meticulously controlled, with atomization air pressure set at 1.1 atm and a fluidizing airflow maintained at 35-45 m3/h. Characterization of the coated cellets, alongside raw materials, was conducted using Fourier Transform Infrared Spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and differential scanning calorimetry (DSC) analyses. Physicochemical evaluations affirmed the successful incorporation of rivaroxaban into hydroxypropyl-β-cyclodextrin, with the final cellets demonstrating excellent flowability, compressibility, and adequate hardness. Quantitative analysis via the HPLC-DAD method confirmed a drug loading of 10 mg rivaroxaban/750 mg coated cellets. In vitro dissolution studies were performed in two distinct media: 0.022 M sodium acetate buffer pH 4.5 with 0.2 % sodium dodecyl sulfate (mirroring compendial conditions for 10 mg rivaroxaban tablets), and 0.05 M phosphate buffer pH 6.8 without surfactants, compared to reference capsules and conventional tablet formulations. The experimental capsules exhibited similar release profiles to the commercial product, Xarelto® 10 mg, with enhanced dissolution rates observed within the initial 10 min. This research presents a significant advancement in the development of solid dosage forms incorporating liquid-state drug-cyclodextrin inclusion complexes, offering a promising avenue for improving drug delivery and bioavailability.

Fabrication of a ternary biocomposite film based on polyvinyl alcohol, cellulose nanocrystals, and silver nanoparticles for food packaging

Silver nanoparticles (AgNPs) were loaded on deprotonated cellulose nanocrystals (CNCd) and incorporated into polyvinyl alcohol (PVA) to develop novel active food packaging films. The AgNPs were fabricated using the liquid phase chemical reduction method using the sodium borohydride reductant of AgNO3. The analysis using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Thermogravimetric analysis (TGA), Differential scanning calorimetry (DSC), and Ultraviolet-visible spectroscopy (UV-Vis) showed that the CNCd surface had a homogeneous distribution of AgNPs with a diameter of about 100 nm. Additionally, CNCd/Ag was successfully incorporated into the PVA film. The developed PVA/CNCd/Ag film showed significantly improved mechanical properties, thermal stability, and UV barrier properties compared to a neat PVA film. The PVA/CNCd/Ag composite film could significantly preserve bananas for 14 days, preventing deterioration and allowing extended storage periods. This composite film generally shows promise in food packaging and prolongs food's shelf life.

Achieving ultrahigh uranium/vanadium selectivity of poly(amidoxime) via coupling MXene-enabled strong intermolecular interaction and separated photothermal interface

Poly(amidoxime) (PAO) has been recognized as the most potential candidate for extracting uranium from seawater, owing to its merits of outstanding uranium affinity, low cost, and large-scale production. Despite remarkable achievements, existing PAO sorbents suffer from unsatisfactory uranium extraction efficiency and selectivity, as imposed by the inherently sluggish uranium adsorption kinetics and inevitable spatial configuration transition of amidoxime, which diminishes uranium affinity. Herein, we discover a facile and integrated design to elaborate a PAO/MXene nanocomposite that delivers ultrahigh and durable uranium/vanadium (U/V) selectivity. The key to our design lies in harnessing MXene-enabled strong intermolecular interactions to PAO to minimize the spatial configuration transition of amidoxime and stabilizing its superior uranium affinity, as well as creating a separated photothermal interface to maximize temperature-strengthened affinity for uranium over vanadium. Such a synergetic effect allows the nanocomposite to acquire over a 4-fold improvement in U/V selectivity compared to that of pure PAO as well as an unprecedented distribution coefficient of uranium compared to most state-of-the-art sorbents. We further demonstrate that our nanocomposite exhibits durable U/V selectivity with negligible attenuation and good antibacterial ability even in long-term operation. The design concept and extraordinary performance in this study bring PAO-based sorbents a step closer to practical uranium extraction from seawater.

Introducing terminal alkyne groups at the reducing end of cellulose nanocrystals by aldimine condensation for further click reaction

In recent years, click reactions with cellulose nanocrystals (CNC) participation have gradually become a research hotspot. Carboxylamine condensation is the most used method to introduce terminal alkyne groups at the reducing end of CNC as reaction sites for click reactions. However, hydroxyl groups on CNC surface would be slightly oxidized during the carboxyamine condensation process, inducing the potential positions of introduced alkynes would be not only at the reducing end but also on CNC surface. Here, aldimine condensation was proposed to introduce terminal alkyne groups just at the reducing end of CNC, and a systematic comparison analysis was conducted with carboxylamine condensation. Firstly, the selectivity and extent of alkynylation were characterized by XPS and EA. Secondly, the end aldehyde content in these CNC samples was measured by the BCA method, which quantitatively explained the grafting efficiency of aldimine condensation and further verified its feasibility. Thirdly, the clickability of the modified CNC samples was confirmed through XPS analysis of the products after a pre-designed click reaction. In sum, aldimine condensation was proven to be a simple and effective strategy for introducing terminal alkyne groups at the reducing end of CNC, which could be used as reaction sites for further click reactions.

Harnessing precursor-directed biosynthesis with glucose derivatives to access cotton fibers with enhanced physical properties

Cotton ovule in vitro cultures are a promising platform for exploring biofabrication of fibers with tailored properties. When the ovules' growth medium is supplemented with chemically synthesized cellulose precursors, it results in their integration into the developing fibers, thereby tailoring their end properties. Here, we report the feeding of synthetic glucosyl phosphate derivative, 6-deoxy-6-fluoro-glucose-1-phosphate (6F-Glc-1P) to cotton ovules growing in vitro, demonstrating the metabolic incorporation of 6F-Glc into the fibers with enhanced mechanical properties and moisture-retention capacity while emphasizing the role of molecular hierarchical architecture in defining functional characteristics and mechanical properties. This incorporation strategy bypasses the early steps of conventional metabolic pathways while broadening the range of functionalities that can be employed to customize fiber end properties. Our approach combines materials science, chemistry, and plant sciences to illustrate the innovation required to find alternative solutions for sustainable production of functional cotton fibers with enhanced and emergent properties.

Enhancement of bacterial cellulose production by ethanol and lactic acid by using Gluconacetobacter kombuchae

The current study intended to analyze the impact of ethanol and lactic acid on the bacterial cellulose yield as well as physicochemical and mechanical properties, by using Gluconacetobacter kombuchae. The optimization of ethanol and lactic acid concentration has been done by using one-way ANOVA. Both the supplements significantly enhance the yield of bacterial cellulose (BC) as compared to the standard Hestrin-Schramm medium (control). Optimization leads to significant increase in BC yield as compared to the control, i.e., the addition, of optimized concentration of lactic acid (0.6%) increases the yield from (0.78 ± 0.026) g to (4.89 ± 0.020) g dry weight, and optimized concentration of ethanol (1%) increases the yield from (0.73 ± 0.057) g to (3.7 ± 0.01) g dry weight. Various physicochemical and mechanical properties of BC films produced in different media (i.e., HS, HS + Ethanol, and HS + Lactic acid), such as the crystallinity, structure, tensile strength, strain at break, Young's modulus, and water holding capacity, were also examined, by employing various techniques such as SEM, FTIR, XRD, etc. BC produced in medium supplemented with the optimum concentration of both the additives were found to possesses higher porosity. Though, slight decline in crystallinity was observed. But the tensile strength and strain at break, were upgraded 1.5-2.5 times, 2-2.5 times, respectively. This article attempted to present a method for enhancing BC yields and characteristics that may lead to more widespread and cost-effective use of this biopolymer.

Fine extraction of cellulose from corn straw and the application for eco-friendly packaging films enhanced with polyvinyl alcohol

Biomass materials substituting for petroleum-based polymers occupy an important position in achieving sustainable development. Cellulose, a typical biomass material, stands out as the primary choice for producing eco-friendly packaging materials. However, it is still a challenge to efficiently utilize cellulose from waste biomass materials in practice. Herein, cellulose-based films were prepared by pretreating waste corn straw, separating straw husk, straw pith and straw leaf, and extracting cellulose through alkali and sodium chlorite treatment to improve its mechanical properties using the cross-linked polyvinyl alcohol (PVA) method in this work. The prepared composite films were characterized by Fourier transform infrared spectrometer (FTIR), X-ray diffraction instrument (XRD), Scanning electron microscopy (SEM), Thermogravimetric (TG) and mechanical properties. The results indicated that corn straw husk exhibited the highest cellulose content of 31.67 wt%, and obtained husk cellulose had the highest crystallinity of 52.5 %. Compared to corn straw, the crystallinity of husk cellulose, pith cellulose and leaf cellulose increased by 19.5 %, 16.4 % and 44.1 %, respectively. Husk cellulose/PVA composite films were the most thermally stable, with a maximum weight loss temperature of 346.8 °C. In addition, the husk cellulose/PVA composite film had the best tensile strength of 37 MPa. Meanwhile, the composite films had good UV shielding, low water vapor transmission rate and biodegradability. Therefore, this work provides a fine utilization route of waste corn straw, and as-prepared cellulose based films have potential application in eco-friendly packaging materials.

Discoloration and Surface Changes in Spruce Wood after Accelerated Aging

Spruce wood is widely used in outdoor applications, but its susceptibility to degradation under exposure to sunlight and moisture is a major concern. This study investigates the impact of accelerated aging on spruce wood's surface chemistry, microstructure, geometry, and discoloration. The study was performed in two outdoor aging modes: dry and wet. The accelerated aging effects were evident in the changes in spruce wood structure, as well as in the other studied properties. During aging, it developed significant discoloration. Under simulated rainless outdoor conditions (dry mode), spruce wood gradually became dark brown. Under conditions involving rain (wet mode), the discoloration was qualitatively different from the dry mode. FTIR spectroscopy showed that during the accelerated aging of wood, lignin was mainly degraded, especially in the early stages of the process. A linear correlation was found between the changes in lignin and the color changes in the wood. There was an increase in carbonyl groups in the dry mode, which contributed to the color change and was also influenced by changes in extractives. The wet mode caused the leaching out of carbonyl groups. The observed decrease in cellulose crystallinity, together with the degradation of hydrophobic lignin, may result in the increased hydrophilicity of photodegraded wood. For both modes, there were different changes in the wood micro- and macrostructure, reflected in the surface morphology. The roughness increased during the aging process in both modes. The slightest changes in the roughness parameters were identified in the grain direction in the dry mode; the most evident was that the roughness parameters increased perpendicular to the grain in the wet mode. The demonstrated mechanism backing up the aging-related changes to the spruce wood structure and the relations unveiled between these changes and the changes in the spruce wood surface properties can provide an issue point for seeking ways how to mitigate the negative effects of the environmental factors the wood is exposed to.

Cellulose/GO monolith covered with Pd-Pt bimetallic nanocrystals for continuous-flow catalytic reduction of hexavalent chromium

Cellulose monolith materials have interconnected open porous structures with very high porosity, making them attractive structures for use as support materials in heterogeneous catalysis applications. In this study, we developed a highly efficient and reusable continuous-flow reactor for Cr(VI) remediation by combining the advantageous features of cellulose monoliths with suitable reinforcement techniques. We fabricated a porous monolithic cellulose/graphene oxide (GO) composite with a continuous three-dimensional skeletal framework using the thermally induced phase separation technique. Pd nanocrystals were synthesized in situ on the surface of the composite monolith, and then converted to porous Pd-Pt bimetallic nanocrystals through a galvanic replacement reaction. This approach eliminated the need for additional reductants and stabilizers, making the process simpler and more environmentally friendly. Under carefully optimized conditions, the cellulose/GO/Pd-Pt nanocomposite monolith exhibited outstanding performance in continuous-flow reactions for Cr(VI) reduction, achieving a maximum conversion rate of 98 %. Moreover, the nanocomposite monolith-based heterogeneous catalyst exhibited remarkable long-term stability, maintaining its catalytic activity even after extended periods of storage in the dried state. These findings highlight the potential of cellulose-based composite monoliths as versatile and robust support materials for heterogeneous catalysis.

Hierarchical and reconfigurable interfibrous interface of bioinspired Bouligand structure enabled by moderate orderliness

Introducing natural Bouligand structure into synthetics is expected to develop high-performance structural materials. Interfibrous interface is critical to load transfer, and mechanical functionality of bioinspired Bouligand structure yet receives little attention. Here, we propose one kind of hierarchical and reconfigurable interfibrous interface based on moderate orderliness to mechanically reinforce bioinspired Bouligand structure. The interface imparted by moderate alignment of adaptable networked nanofibers hierarchically includes nanofiber interlocking and hydrogen-bonding (HB) network bridging, being expected to facilitate load transfer and structural stability through dynamic adjustment in terms of nanofiber sliding and HB breaking-reforming. As one demonstration, the hierarchical and reconfigurable interfibrous interface is constructed based on moderate alignment of networked bacterial cellulose nanofibers. We show that the resultant bioinspired Bouligand structural material exhibits unusual strengthening and toughening mechanisms dominated by interface-microstructure multiscale coupling. The proposed interfibrous interface enabled by moderate orderliness would provide mechanical insight into the assembly of widely existing networked nanofiber building blocks toward high-performance macroscopic bioinspired structural assemblies.

Boron-mediated amelioration of copper toxicity in Citrus sinensis seedlings involved reduced concentrations of copper in leaves and roots and their cell walls rather than increased copper fractions in their cell walls

Little information is available on how boron (B) supplementation affects plant cell wall (CW) remodeling under copper (Cu) excess. 'Xuegan' (Citrus sinensis) seedlings were submitted to 0.5 or 350 µM Cu × 2.5 or 25 µM B for 24 weeks. Thereafter, we determined the concentrations of CW materials (CWMs) and CW components (CWCs), the degree of pectin methylation (DPM), and the pectin methylesterase (PME) activities and PME gene expression levels in leaves and roots, as well as the Cu concentrations in leaves and roots and their CWMs (CWCs). Additionally, we analyzed the Fourier transform infrared (FTIR) and X-ray diffraction (XRD) spectra of leaf and root CWMs. Our findings suggested that adding B reduced the impairment of Cu excess to CWs by reducing the Cu concentrations in leaves and roots and their CWMs and maintaining the stability of CWs, thereby improving leaf and root growth. Cu excess increased the Cu fractions in leaf and root pectin by decreasing DPM due to increased PME activities, thereby contributing to citrus Cu tolerance. FTIR and XRD indicated that the functional groups of the CW pectin, hemicellulose, cellulose, and lignin could bind and immobilize Cu, thereby reducing Cu cytotoxicity in leaves and roots.

In situ retention of lignin-rich bamboo green effectively improves the surface properties of flattened bamboo

Bamboo has tremendous carbon sequestration potential, and bamboo green is underutilized. This work devised a green-keeping technique in bamboo flattening that preserved natural bamboo green in-situ. The impacts of flattening and green-keeping on bamboo morphology, chemical composition, physical qualities, and composite applications were examined. Bamboo cells were wrinkled after flattening, while bamboo green exhibited a more homogenous surface. Bamboo cellulose crystallinity increased after flattening, hemicellulose deteriorated little, and relative lignin content increased. The hydrophobicity and mildew resistance of the surface of G-FB (green-kept flattened bamboo board) were improved. Compared to untreated bamboo, FB and G-FB had 61.1 % and 49.5 % higher tensile strength and 8.0 % and 33.2 % higher MOR. G-FB-made flooring exhibited a MOR of 134.7 MPa and upgraded surface properties. Bamboo green preservation boosted utilization of materials and improved flattened bamboo's exterior surface without affecting lamination bonding. Simple bamboo green preservation multifunctionalizes flattened bamboo composites.

Dual-responsive in situ gelling polymer matrix for tunable ketamine general anesthesia in experimental animals

Animal experimentation is a critical part of the drug development process and pharmaceutical research. General anesthesia is one of the most common procedures. Careful administration and dosing of anesthetics ensure animal safety and study success. However, repeated injections are needed to maintain anesthesia, leading to adverse effects. Ketamine, a dissociative anesthetic, is commonly used for inducing anesthesia in animals and suffers from a short half-life requiring repeated dosing. Herein, we report a novel system for controlled anesthesia post-intraperitoneal administration. A polymer solution called "premix" was developed using two stimuli-responsive polymers, Pluronic (PF) and Carbopol (CP). As the premix was mixed with ketamine solution and injected, it underwent in situ gelation, hence controlling ketamine release and anesthesia. The PF and CP concentrations were optimized for the gelation temperature and viscosity upon mixing with the ketamine solution. The optimal premix/ketamine formulation (1.5:1) was liquid at room temperature and gel at physiological conditions with favorable mucoadhesion and rheology. Premix retarded the release of ketamine, translating to tunable anesthesia in vivo. Anesthesia duration and recovery were tunable per ketamine dose with minimal side effects. Therefore, we propose the implementation of PF/CP premix as a vehicle for general anesthesia in animals for optimal duration and effect.

Targeting Bacterial Nanocellulose Properties through Tailored Downstream Techniques

Bacterial nanocellulose (BNC) is a biodegradable polysaccharide with unique properties that make it an attractive material for various industrial applications. This study focuses on the strain Komagataeibacter medellinensis ID13488, a strain with the ability to produce high yields of BNC under acidic growth conditions and a promising candidate to use for industrial production of BNC. We conducted a comprehensive investigation into the effects of downstream treatments on the structural and mechanical characteristics of BNC. When compared to alkaline-treated BNC, autoclave-treated BNC exhibited around 78% superior flexibility in average, while it displayed nearly 40% lower stiffness on average. An SEM analysis revealed distinct surface characteristics, indicating differences in cellulose chain compaction. FTIR spectra demonstrated increased hydrogen bonding with prolonged interaction time with alkaline solutions. A thermal analysis showed enhanced thermal stability in alkaline-treated BNC, withstanding temperatures of nearly 300 °C before commencing degradation, compared to autoclaved BNC which starts degradation around 200 °C. These findings provide valuable insights for tailoring BNC properties for specific applications, particularly in industries requiring high purity and specific mechanical characteristics.

Preparation and functionalization of cellulose nanofibers using a naturally occurring acid and their application in stabilizing linseed oil/water Pickering emulsions

Finding efficient and environmental-friendly methods to produce and chemically modify cellulose nanofibers (CNFs) remains a challenge. In this study, lactic acid (LA) treatment followed by microfluidization was employed for the isolation and functionalization of CNFs. Small amounts of HCl (0.01, 0.1, and 0.2 M) were used alongside LA to intensify cellulose hydrolysis. FTIR spectroscopy and solid-state 13C NMR confirmed the successful functionalization of CNFs with lactyl groups during isolation, while SEM, AFM, and rheological tests revealed that the addition of HCl governed the fibers' sizes and morphology. Notably, the treatment with LA and 0.2 M HCl resulted in a more efficient defibrillation, yielding smaller nanofibers sizes (62 nm) as compared to the treatment with LA or HCl alone (90 and 108 nm, respectively). The aqueous suspension of CNFs treated with LA and 0.2 M HCl showed the highest viscosity and storage modulus. LA-modified CNFs were tested as stabilizers for linseed oil/water (50/50 v/v) emulsions. Owing to the lactyl groups grafted on their surface and higher aspect ratio, CNFs produced with 0.1 and 0.2 M HCl led to emulsions with increased stability (a creaming index increase of only 3 % and 1 %, respectively, in 30 days) and smaller droplets sizes of 23.4 ± 1.2 and 35.5 ± 0.5 μm, respectively. The results showed that LA-modified CNFs are promising stabilizers for Pickering emulsions.

Identification of Gluconacetobacter xylinus LYP25 and application to bacterial cellulose production in biomass hydrolysate with acetic acid

Bacterial cellulose (BC) is a remarkable biomacromolecule with potential applications in food, biomedical, and other industries. However, the low economic feasibility of BC production processes hinders its industrialization. In our previous work, we obtained candidate strains with improved BC production through random mutations in Gluconacetobacter. In this study, the molecular identification of LYP25 strain with significantly improved productivity, the development of chestnut pericarp (CP) hydrolysate medium, and its application in BC fermentation were performed for cost-effective BC production process. As a result, the mutant strain was identified as Gluconacetobacter xylinus. The CP hydrolysate (CPH) medium contained 30 g/L glucose with 0.4 g/L acetic acid, whereas other candidates known to inhibit fermentation were not detected. Although acetic acid is generally known as a fermentation inhibitor, it improves the BC production by G. xylinus when present within about 5 g/L in the medium. Fermentation of G. xylinus LYP25 in CPH medium resulted in 17.3 g/L BC, a 33 % improvement in production compared to the control medium, and BC from the experimental and control groups had similar physicochemical properties. Finally, the overall process of BC production from biomass was evaluated and our proposed platform showed the highest yield (17.9 g BC/100 g biomass).

Phasor-FLIM analysis of cellulose paper ageing mechanism with carbotrace 680 dye

Ageing of paper is a complex process of great relevance for application purposes because of its widespread use as support for information storage in books and documents, and as common low-cost and green packaging material, to name a few. A key factor in paper ageing is the oxidation of cellulose, a macromolecule of natural origin that constitutes the main chemical component of paper. Such a complex process results in changes in the cellulose polymeric chains in chemical and structural properties. The scope of this work is to explore the effects of oxidation of cellulose as one of the principal mechanisms of ageing of paper using a fluorescence-based approach. To this aim, fluorescence-lifetime imaging microscopy (FLIM) measurements on pure cellulose samples stained using Carbotrace 680 dye were performed, and data were analyzed by phasor approach. The comparison with results from conventional techniques allowed to map paper microstructure as a function of the sample oxidation degree correlating the fluorescence-lifetime changes to cellulose oxidation. A two-step oxidation kinetics that produced specific modification in paper organization was highlighted indicating that FLIM measurements using Carbotrace 680 dye may provide a simple tool to obtain information on the oxidation process also adding spatial information at sub-micrometric scale.

Comprehensive analysis of cationic dye removal from synthetic and industrial wastewater using a semi-natural curcumin grafted biochar/poly acrylic acid composite hydrogel

Polymer composites offer a tailored framework as an exceptional candidate for water treatment due to their tunable chemical structure, porous 3D architecture, physiochemical stability, accessibility, pH-sensitivity and ease of use. In this study, curcumin-engineered biochar is embedded into a cross-linked polyacrylic acid hydrogel matrix using in situ polymerization for developing a semi-natural adsorbent for the removal of cationic dye from an aqueous solution. The physicochemical features of the generated composite hydrogel are significantly influenced by the implementation of curcumin-grafted biochar into the polyacrylic acid substrate. Comprehensive characteristic approaches were employed to explore all aspects of the adsorbent's properties, especially its removal efficacy. The methodical adsorption study was accomplished by monitoring dynamic factors such as pH, adsorbent content, time frame, and initial dye concentration. The presence of the porous aromatized structure of biochar, active oxygen-enrich functional groups (carboxyl, hydroxyl, keto, enol, ether) coupled with the conjugated curcumin structure facilitate the effective establishment of hydrogen bonds, electrostatic interactions, π-π interactions, electron donor-acceptor and charge-assisted H-bonding with the malachite green (MG) and rhodamine B (Rho) molecules. The highest adsorption capacities of MG and Rho reached 521 mg g-1 and 741 mg g-1 respectively, in the range of neutral pH, considering their molecular nature, functionalities, and unique adsorption mechanisms. The isothermal modeling was carried out with Henry, Langmuir, Jovanovic, Freundlich, Temkin, and Koble-Corrigan models to determine the adsorption system. Additionally, the kinetic data were assessed with Bangham, pseudo-first-order, pseudo-second-order, intra-particle, and liquid film diffusion models to ascertain the rate-limiting phase. The Koble-Corrigan and Langmuir isotherm models (R2 > 0.997) as well as pseudo-second-order (R2 > 0.998) and Elovich (R2 = 0.983 and 0.995) kinetics models provide a substantial level of concordance with empirical findings. The analysis of non-linear diffusion models revealed that the Bangham (R2 > 0.995) pore and liquid film diffusion (R2 > 0.960) models has major influence on the rate of the adsorption procedure. The binary adsorption test demonstrated higher efficacy of the synthesized adsorbent in the removal of malachite as compared to rhodamine. This study sheds light on the design of a cost-effective semi-natural polymeric composite for treating dye-polluted wastewaters, a major milestone toward environmental and ecological sustainability.

Radiation processing of bacterial cellulose-monolaurin wound dressing: Physicochemical effects, functional analysis, and sterilization

A commercial bacterial cellulose-monolaurin wound dressing was investigated for changes in the chemical structure, mechanical strength, thermal degradation, morphology, and functional swelling properties after exposure to gamma and electron beam radiations at doses 15-50 kGy. Radiation-induced oxidation occurred as seen in the FT-IR peaks at 1720-1750 cm-1. Degradation of the cellulosic network was observed in tensile strength reduction and shift in degradation temperature to lower values. The SEM cross-section images of the irradiated dressings revealed a less dense nanostructure network compared to the non-irradiated samples while the XRD diffractograms indicated a change in lattice direction/plane. Despite these changes, irradiation caused no significant effect on the functional properties especially at 15-25 kGy doses where most biomedical devices are sterilized. All irradiated wound dressings exhibited physical integrity, increased exudate absorption, and water vapor transmission rate - properties beneficial to wound-healing functionality. The pre-selected sterilization dose of 15 kGy for each ionizing radiation was successfully verified and substantiated following ISO 11137-2:2016, hence ionizing radiation is a suitable sterilization modality for the product.

Properties of sodium alginate-based nanocomposite films: Effects of aspect ratio and surface charge of cellulose nanocrystals

Three cellulose nanocrystals (CNCs) were prepared to reinforce sodium alginate (SA) films. This study investigated effects of aspect ratio (L/D) and surface charge of three CNCs (CCNC, MCNC, and WCNC) on the properties of films. At CNC concentrations ≤3 wt%, MCNC, with a medium L/D but the lowest surface charge density among the three CNCs, exhibited the highest efficiency in enhancing the Young's modulus and tensile strength of films. This indicated that, apart from L/D, CNC's surface charge density also affected its reinforcing effects in anionic SA-based films. Compared with other CNCs, MCNC with the lowest charge density exhibited weaker repulsion with SA, potentially contributing to stronger interfacial interactions between them. At concentrations >3 wt%, the reinforcing efficiency of MCNC was extremely close to that of WCNC, which had the highest L/D but medium charge density. This was possibly because, according to SEM results, MCNC with the lowest absolute value of zeta potential aggregated more severely than other CNCs. However, both MCNC and WCNC were consistently more efficient than CCNC. Moreover, FTIR results revealed that WCNC formed more hydrogen bonds with SA than other CNCs. Consequently, adding WCNC was more effective in reducing films' water vapor permeability and hydrophilicity.

Enhanced mechanical properties and biocompatibility of bacterial cellulose composite films with inclusion of 2D MoS2 and helical carbon nanotubes for use as antimicrobial drug carriers

Bacterial cellulose (BC) is a biomaterial being investigated for a range of applications. Herein, BC films derived from nata de coco pieces are reinforced by two-dimensional molybdenum disulfide (MoS2) and helical carbon nanotubes (HCNTs) to enhance their tensile mechanical properties, and the biocompatibility of the BC composite films is demonstrated. A simple preparation is presented using a kitchen blender to disperse and blend the BC fibers and additives in a common fabrication medium, followed by vacuum filtration. The mechanical properties of the BC/MoS2/HCNTs composite films are enhanced due to the synergistic effect of MoS2 and HCNTs embedded in the BC films. The MoS2/HCNTs binary additive (1 phr) is capable of increasing the strength and Young's modulus by 148 % and 333 %, respectively, relative to the BC films. The cell cytotoxicity of the BC/MoS2/HCNTs films was assessed using an MTT assay. The composite films are biocompatible with a cell viability of L929 fibroblast cells >70 %, coupled with observations of direct cell attachment on the films. The composite films also exhibited good performance in absorbing and releasing gentamicin antibiotics to inhibit the growth of Escherichia coli and Staphylococcus aureus. The BC/MoS2/HCNTs films are thus potential BC-based candidates as biocompatible robust antibiotic carriers.

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.

Co-production of pigment and high value-added bacterial nanocellulose from Suaeda salsa biomass with improved efficiency of enzymatic saccharification and fermentation

This study evaluated the co-production of pigment and bacterial nanocellulose (BNC) from S. salsa biomass. The extraction of the beet red pigment reduced the salts and flavonoids contents by 82.7%-100%, promoting the efficiencies of enzymatic saccharification of the biomass and the fermentation of BNC from the hydrolysate. SEM analysis revealed that the extraction process disrupted the lignocellulosic fiber structure, and the chemical analysis revealed the lessened cellulase inhibitors, consequently facilitating enzymatic saccharification for 10.4 times. BNC producing strains were found to be hyper-sensitive to NaCl stress, produced up to 400.4% more BNC from the hydrolysate after the extraction. The fermentation results of BNC indicated that the LDU-A strain yielded 2.116 g/L and 0.539 g/L in ES-M and NES-M, respectively. In comparison to the control, the yield in ES-M increased by approximately 20.0%, while the enhancement in NES-M was more significant, reaching 292.6%. After conducting a comprehensive characterization of BNC derived from S. salsa through Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), and Thermogravimetric Analysis (TGA), the average fiber diameter distribution of these four BNC materials ranges from 22.23 to 33.03 nanometers, with a crystallinity range of 77%-90%. Additionally, they exhibit a consistent trend during the thermal degradation process, further emphasizing their stability in high-temperature environments and similar thermal properties. Our study found an efficient co-production approach of pigment and BNC from S. salsa biomass. Pigment extraction made biomass more physically and chemically digestible to cellulase, and significantly improved BNC productivity and quality.

Molecular Cloning, In Silico Analysis, and Characterization of a Novel Cellulose Microfibril Swelling Gene Isolated from Bacillus sp. Strain AY8

A novel cellulose microfibril swelling (Cms) gene of Bacillus sp. AY8 was successfully cloned and sequenced using a set of primers designed based on the conserved region of the gene from the genomic database. The molecular cloning of the Cms gene revealed that the gene consisted of 679 bp sequences encoding 225 amino acids. Further in silico analysis unveiled that the Cms gene contained the NlpC/P60 conserved region that exhibited a homology of 98% with the NlpC/P60 family proteins found in both the strains, Burkholderialata sp. and Burkholderia vietnamiensis. The recombinant Cms enzyme had a significant impact on the reduction of crystallinity indices (CrI) of various substrates including a 3%, a 3.97%, a 4.66%, and a substantial 14.07% for filter paper, defatted cotton fiber, avicel, and alpha cellulose, respectively. Additionally, notable changes in the spectral features were observed among the substrates treated with recombinant Cms enzymes compared to the untreated control. Specifically, there was a decrease in band intensities within the spectral regions of 3000-3450 cm-1, 2900 cm-1, 1429 cm-1, and 1371 cm-1 for the treated filter paper, cotton fiber, avicel, and alpha cellulose, respectively. Furthermore, the recombinant Cms enzyme exhibited a maximum cellulose swelling activity at a pH of 7.0 along with a temperature of 40 °C. The molecular docking data revealed that ligand molecules, such as cellobiose, dextrin, maltose 1-phosphate, and feruloyated xyloglucan, effectively bonded to the active site of the Cms enzyme. The molecular dynamics simulations of the Cms enzyme displayed stable interactions with cellobiose and dextrin molecules up to 100 ns. It is noteworthy to mention that the conserved region of the Cms enzyme did not match with those of the bioadditives like expansins and swollenin proteins. This study is the initial report of a bacterial cellulose microfibril swellase enzyme, which could potentially serve as an additive to enhance biofuel production by releasing fermentable sugars from cellulose.

On the Mechanism of the Ionizing Radiation-Induced Degradation and Recycling of Cellulose

The use of ionizing radiation offers a boundless range of applications for polymer scientists, from inducing crosslinking and/or degradation to grafting a wide variety of monomers onto polymeric chains. This review in particular aims to introduce the field of ionizing radiation as it relates to the degradation and recycling of cellulose and its derivatives. The review discusses the main mechanisms of the radiolytic sessions of the cellulose molecules in the presence and absence of water. During the radiolysis of cellulose, in the absence of water, the primary and secondary electrons from the electron beam, and the photoelectric, Compton effect electrons from gamma radiolysis attack the glycosidic bonds (C-O-C) on the backbone of the cellulose chains. This radiation-induced session results in the formation of alkoxyl radicals and C-centered radicals. In the presence of water, the radiolytically produced hydroxyl radicals (●OH) will abstract hydrogen atoms, leading to the formation of C-centered radicals, which undergo various reactions leading to the backbone session of the cellulose. Based on the structures of the radiolytically produced free radicals in presence and absence of water, covalent grafting of vinyl monomers on the cellulose backbone is inconceivable.

Multifunctional Hydrogels Based on Cellulose and Modified Lignin for Advanced Wounds Management

Considering the complex process of wound healing, it is expected that an optimal wound dressing should be able to overcome the multiple obstacles that can be encountered in the wound healing process. An ideal dressing should be biocompatible, biodegradable and able to maintain moisture, as well as allow the removal of exudate, have antibacterial properties, protect the wound from pathogens and promote wound healing. Starting from this desideratum, we intended to design a multifunctional hydrogel that would present good biocompatibility, the ability to provide a favorable environment for wound healing, antibacterial properties, and also, the capacity to release drugs in a controlled manner. In the preparation of hydrogels, two natural polymers were used, cellulose (C) and chemically modified lignin (LE), which were chemically cross-linked in the presence of epichlorohydrin. The structural and morphological characterization of CLE hydrogels was performed by ATR-FTIR spectroscopy and scanning electron microscopy (SEM), respectively. In addition, the degree of swelling of CLE hydrogels, the incorporation/release kinetics of procaine hydrochloride (PrHy), and their cytotoxicity and antibacterial properties were investigated. The rheological characterization, mechanical properties and mucoadhesion assessment completed the study of CLE hydrogels. The obtained results show that CLE hydrogels have an increased degree of swelling compared to cellulose-based hydrogel, a better capacity to encapsulate PrHy and to control the release of the drug, as well as antibacterial properties and improved mucoadhesion. All these characteristics highlight that the addition of LE to the cellulose matrix has a positive impact on the properties of CLE hydrogels, confirming that these hydrogels can be considered as potential candidates for applications as oral wound dressings.

Effect of the Addition of Fique Bagasse Cellulose Nanoparticles on the Mechanical and Structural Properties of Plastic Flexible Films from Cassava Starch

One of the activities most representative of the agricultural sector in Colombia is the production of biodegradable fique fiber. The efficiency of the defiberization process of the fique leaves is very low since a mere 4% of the total weight of the leaf (cabuya) is used and marketed. The remaining 96%, composed of fique juice and bagasse, is considered to be waste and discarded, impacting the environment. The aim of this work was to study fique bagasse as a source of cellulose nanoparticles (CNCs). CNCs were obtained by acid hydrolysis and added at 10% to films made from cassava thermoplastic starch (TPS) by the casting method. Structural changes in the CNCs, TPS, and their mixtures were characterized by FTIR-ATR and their morphology and particle size by SEM and TEM microscopy, respectively. Thermal properties were analyzed using DSC and TGA, along with their effect on mechanical properties. Changes in the FTIR spectra indicated that the chemical method adequately removed hemicellulose and lignin from the fiber surface of fique bagasse. The CNCs showed a diameter and length of 7.5 ± 3.9 and 52.7 ± 18.1 nm, respectively, and TPS 10% CNC obtained an increase in mechanical strength of 116%. The obtainment of CNCs from lignocellulosic materials can thus be viewed as a favorable option for the subsequent reinforcement of a polymeric matrix.

Preparation and characterization of porous membranes of glucomannan and silver decorated cellulose nanocrystals for application as biomaterial

Bacterial infection usually represents a threat in medical wound care, due to the increase in treatment complexity and the risk of antibiotic resistance. For presenting interesting characteristics for the use as biomaterial, natural polymers have been explored for this application. Among them, a promising candidate is the konjac glucomannan (KGM) with outstanding biocompatibility and biodegradability but lack of antibacterial activity. In this study, KGM was combined with silver decorated cellulose nanocrystals (CNC-Ag) to prepare membranes by using a recent reported casting-freezing method. The results highlight the potential anti-adhesive activity of the new materials against Staphylococcus aureus upon contact, without the burst release of silver nanoparticles. Furthermore, the incorporation of CNC enhanced the thermal stability of these membranes while preserving the favorable mechanical properties of the KGM-based material. These findings highlight a straightforward approach to enhance the antibacterial properties of natural polymers, which can be effectively useful in medical devices like wound dressings that typically lack such properties.

Comparison and assessment of methods for cellulose crystallinity determination

The degree of crystallinity in cellulose significantly affects the physical, mechanical, and chemical properties of cellulosic materials, their processing, and their final application. Measuring the crystalline structures of cellulose is a challenging task due to inadequate consistency among the variety of analytical techniques available and the lack of absolute crystalline and amorphous standards. Our article reviews the primary methods for estimating the crystallinity of cellulose, namely, X-ray diffraction (XRD), nuclear magnetic resonance (NMR), Raman and Fourier-transform infrared (FTIR) spectroscopy, sum-frequency generation vibrational spectroscopy (SFG), as well as differential scanning calorimetry (DSC), and evolving biochemical methods using cellulose binding molecules (CBMs). The techniques are compared to better interrogate not only the requirements of each method, but also their differences, synergies, and limitations. The article highlights fundamental principles to guide the general community to initiate studies of the crystallinity of cellulosic materials.

Analysis of classical techniques precision on the measurement of cellulose moisture gain/loss

The precision of the four classical techniques (Karl-Fischer titration, (thermo)gravimetric method, Fourier-transform infrared (FT-IR) and near infrared (NIR) spectroscopies) commonly used in the analysis of cellulose moisture absorption/desorption has been deeply investigated regarding the reproducibility of these processes. Based on multiple repeated experiments, cellulose water content values obtained with Karl-Fischer titration and (thermo)gravimetric method were plotted as a function of time. Then, the cautious peak-by-peak analysis of the absorbance and wavenumber shifts visible in IR spectra has been carried out. The collected data was described using boxplots that provided valuable information on the experimental points spread. It has been successfully proven that gravimetric methods allow for precise drawing of moisture absorption and desorption curves, while Karl-Fischer titration, ATR FT-IR and NIR techniques provide the possibility of the moisture absorption/desorption processes description by linear mathematical models (R2 >90%). Therefore, this study provides a systematic comparison between various analytical methods.

Lithiated Phosphoryl Cellulose Nanocrystals Enhance Cycling Stability and Safety of Quasi-Solid-State Lithium Metal Batteries

Cycling stability and safety are two of the main challenges facing lithium metal batteries with metallic lithium as anodes. Quasi-solid-state lithium metal batteries based on gel polymer electrolytes are one of the important development directions for lithium metal batteries addressing those challenges. Herein, we prepare lithiated phosphoryl cellulose nanocrystals (PCNC-Li) as a modification material for poly(vinylidene fluoride) (PVDF) gel polymer electrolyte to improve cycling stability and safety of quasi-solid-state lithium metal batteries. The synthesized PCNC-Li tends to form a uniform network structure on the surface of the PVDF membrane, in which the phosphoryl groups grafted regularly on celluloses can regulate the transport of lithium ions. As a result, a more uniform ion flux and more stable lithium anode interface support an obviously improved cycling stability for lithium metal batteries. Moreover, the introduction of the PCNC-Li coating layer makes the modified PVDF membranes have a better thermal stability and an enhanced mechanical strength, which is beneficial for improvement of safety of lithium metal batteries. This work provides a new alternative to fabricating a better composite gel polymer electrolyte for lithium metal batteries.

Unraveling the control of reversibility for actuators based on cellulose nanofibers

In this work, we have prepared cellulose-based actuators taking advantage of the pH-sensitive solubility of chitosan (CH) and the mechanical strength of CNFs. Bilayer films were prepared by vacuum filtration inspired by plant structures that exhibit reversible deformation under pH changes. The presence of CH in one of the layers led to asymmetric swelling at low pH, thanks to the electrostatic repulsion between charged amino groups of CH, and the subsequent twisting with the CH layer on the outside. Reversibility was achieved by substituting pristine CNFs with carboxymethylated CNFs (CMCNFs), that are charged at high pH and thus competed with the effects of amino groups. Swelling and mechanical properties of layers under pH changes were studied by gravimetry and dynamic mechanical analysis (DMA) to quantify the contribution of chitosan and the modified CNFs on the reversibility control. This work evidenced the key role of surface charge and layer stiffness to achieve reversibility. Bending was triggered by the different water uptake of each layer, and shape recovery was achieved when the shrunk layer shower higher rigidity than the swollen layer.

Sustainable Solutions for Oral Health Monitoring: Biowaste-Derived Triboelectric Nanogenerator

Oral healthcare monitoring is a vital aspect of identifying and addressing oral dental problems including tooth decay, gum pain, and oral cancer. Day by day, healthcare facilities and regular checkups are becoming more costly and time-consuming. In this context, consumers are moving toward advanced technology, such as bite sensors, to obtain regular data about their occlusal chewing patterns and strength. The triboelectric nanogenerator (TENG) can potentially eliminate the need for a battery by simply converting abundant vibrations from nature or human motion into electrical energy. In this work, biomaterials are obtained from biowastes such as cellulose from wood waste, chitosan from crab shells, and gelatin from fish scales. All wastes are biodegradable, and our work aims at sustainability and waste hierarchy. The single electrode mode-based TENG was designed and fabricated using biodegradable poly(vinyl alcohol) (PVA)-biomaterial composites, rice paper as a substrate, and edible silver leaf as an electrode. The highest electrical output was obtained for PVA/chitosan 10 wt % composite-based TENG (PC10) of about 20 V, 200 nA, and 12 nC. The biomechanical energy harvesting was measured, and powering of LED was demonstrated using a PC10 TENG device. A biocompatible bite sensor based on the TENG was used to measure the biting force of a dummy teeth model to demonstrate its potential use in dental health applications. It indicates the promising future value of disposable oral medication devices without any invasive surgery or injection.

Modification of microstructure and selected physicochemical properties of bacterial cellulose produced by bacterial isolate using hydrocolloid-fortified Hestrin-Schramm medium

Bacterial cellulose (BC) is a biopolymer with applications in numerous industries such as food and pharmaceutical sectors. In this study, various hydrocolloids including modified starches (oxidized starch-1404 and hydroxypropyl starch-1440), locust bean gum, xanthan gum (XG), guar gum, and carboxymethyl cellulose were added to the Hestrin-Schramm medium to improve the production performance and microstructure of BC by Gluconacetobacter entanii isolated from coconut water. After 14-day fermentation, medium supplemented with 0.1% carboxymethyl cellulose and 0.1% XG resulted in the highest BC yield with dry BC content of 9.82 and 6.06 g/L, respectively. In addition, scanning electron microscopy showed that all modified films have the characteristic three-dimensional network of cellulose nanofibers with dense structure and low porosity as well as larger fiber size compared to control. X-ray diffraction indicated that BC fortified with carboxymethyl cellulose exhibited lower crystallinity while Fourier infrared spectroscopy showed characteristic peaks of both control and modified BC films.

The crystalline structure transition and hydrogen bonds shift determining enhanced enzymatic digestibility of cellulose treated by ultrasonication

Global energy issue raised the necessity to develop second-generation biofuels, and biorefinery of cellulosic biomass becomes a promising solution. Various pretreatments were used to overcome the cellulose nature of recalcitrance and improve the enzymatic digestibility, but the lack of mechanism understanding hindered the development of efficient and cost-effective technologies of cellulose utilization. Using structure-based analysis, we demonstrate that the improved hydrolysis efficiency caused by ultrasonication was ascribed to the changed cellulose properties rather than the increased dissolubility. Further, isothermal titration calorimetry (ITC) analysis suggested that enzymatic digestion of cellulose is an entropically favored reaction driven by hydrophobic forces other than an enthalpically favored reaction. The changes in cellulose properties and thermodynamic paramenters due to ultrasonication accounted for the improved accessibility. Ultrasonication-treated cellulose showed porous, rough and disordered morphology, accompanying with the loss of crystalline structure. Despite the unaffected unit cell structure, ultrasonication expanded the crystalline lattice by increasing grain sizes and average cross-sectional area, resulting in the transformation from cellulose I to cellulose II, with the decreased crystallinity, better hydrophilicity and increased enzymatic bioaccessibility. Furthermore, FTIR combined with two-dimensional correlation spectroscopy (2D-CoS) verified that the sequential shift of hydroxyl group and intramolecular/intermolecular hydrogen bonds, the functional groups governing cellulose crystal structure and stability, accounted for the ultrasonication-induced transition of cellulose crystalline structure. This study provides a comprehensive picture of cellulose structure and property response caused by mechanistic treatments and will open up avenues to develop novel pretreatments for efficient utilization.

Sustainable Photocatalytic Desizing Process for the Starch-Based Size

Textile wet processing highly impacts the environment due to its massive water and energy consumption. High consumption of water also results in the generation of a considerable volume of effluents. In this regard, an ultraviolet C (UVC)-assisted desizing method of starch-sized cotton fabric has been developed to lower the utility consumption in textile pretreatment. A UVC cabinet is designed to control exposing temperature and energy of exposure on the starch-sized cotton fabric. The UVC exposure time is optimized concerning the desizing efficiency. The UVC-exposed-sized fabric is washed with different washing times and washing temperatures to optimize the process. The alkali consumption in washing is reduced by 75% and desizing efficiency is improved to 95%. The application of oxidizing agents like NaNO₂, K₂S₂O₈, and NaBO₃·4H₂O during sizing further reduced the washing temperature and washing time for desizing to obtain 100% desizing efficiency. The UVC-assisted desized fabric is characterized by the whiteness index, water absorbency, tensile strength, Fourier transform infrared (FTIR), and wide-angle X-ray diffraction and compared with the control. The UVC-assisted desizing process has the potential to save approximately 60% water, 90% energy, and more than 70% of the time. Life cycle analysis has also been done. The photocatalytic desizing process can reduce the impact on human health by more than 85% and save approximately 69% of mineral resources than the conventional technique. The textile industry can quickly adopt a novel approach for sustainable desizing.

Determination of black soldier fly larvae performance for oil palm based waste reduction and biomass conversion

Oil palm biomass, such as empty fruit bunches and palm kernel meal, has low digestibility. Thus, a suitable bioreactor is urgently needed to efficiently convert oil palm biomass into high-value products. The polyphagous black soldier fly (BSF, Hermetia illucens) has gained global attention for its role in biomass conversion. However, there is scarce information on the ability of the BSF to sustainably manage highly lignocellulosic matter, such as oil palm empty fruit bunches (OPEFB). Therefore, this study aimed to investigate the performance of the black soldier fly larvae (BSFL) in oil palm biomass management. Several formulations were fed to the BSFL five days after hatching (DAH), and the effects on oil palm biomass-based substrate waste reduction and biomass conversion were analyzed. Furthermore, the resulting growth parameters correlating to the treatments were evaluated, including feed conversion rate (FCR), survival rates, and developmental rates. The most optimal results were obtained by mixing 50% of palm kernel meal (PKM) with 50% of coarse oil palm empty fruit bunches (OPEFB), resulting in an FCR of 3.98 ± 0.08 and a survival rate of 87% ± 4.16. Moreover, this treatment is a promising method for waste reduction (11.7% ± 6.76), with a bioconversion efficiency (corrected for residue) of 71.5% ± 1.12. In conclusion, the study findings indicate that incorporating PKM into OPEFB substrate can substantially alter BSFL growth, reduce oil palm waste, and optimize biomass conversion.

Enhancing the Performance of Triboelectric Generator: A Novel Approach Using Solid-Liquid Interface-Treated Foam and Metal Contacts

This work introduces a novel approach for enhancing the performance of a triboelectric generator (TEG) by using a solid-liquid interface-treated foam (SLITF) as its active layer, combined with two metal contacts of different work functions. SLITF is made by absorbing water into a cellulose foam, which enables charges generated by friction energy during the sliding motion to be separated and transferred through the conductive path formed by the hydrogen-bonded network of water molecules. Unlike traditional TEGs, the SLITF-TEG demonstrates an impressive current density of 3.57 A/m² and can harvest electric power up to 0.174 W/m² with an induced voltage of approximately 0.55 V. The device generates a direct current in the external circuit, eliminating the limitations of low current density and alternating current found in traditional TEGs. By connecting six-unit cells of SLITF-TEG in series and parallel, the peak voltage and current can be increased up to 3.2 V and 12.5 mA, respectively. Furthermore, the SLITF-TEG has the potential to serve as a self-powered vibration sensor with high accuracy (R² = 0.99). The findings demonstrate the significant potential of the SLITF-TEG approach for efficiently harvesting low-frequency mechanical energy from the natural environment, with broad implications for a range of applications.

A Flexible and Highly Sensitive Pressure Sense Electrode Based on Cotton Pulp for Wearable Electronics

Flexible pressure sensors with high sensitivity have great potential applications in wearable electronics. However, it is still a great challenge to prepare sense electrodes with high flexibility, high sensitivity, and high electrochemical performance. Here, we propose a novel and simple method for carbonizing cotton fibers as excellent electrically conductive materials. Moreover, carbonized cotton fiber (CCF) and polydimethylsiloxane (PDMS) were assembled into a flexible sense electrode. The CCF/PDMS electrode shows a high sensitivity of 10.8 kPa^-1, a wide response frequency from 0.2-2.0 Hz, and durability over 900 cycles. The combined CCF/PDMS sensors can monitor human movement and pulse vibration, showing the enormous potential for use in wearable device technology. Additionally, the CCF/PDMS can be used as electrodes with a specific capacitance of 332.5 mF cm^-2 at a current density of 5 mA cm^-2, thanks to their high electrical conductivity and hydrophilicity, demonstrating the promising prospect of flexible supercapacitors.

Mesoporous chitosan derivatives for effective uranyl sorption: Synthesis, characterization, and mechanism-application to ore leachate

Two sorbents were developed from chitosan aminophosphonation: via one-pot process to produce aminophosphonated derivative (r-AP), followed by further pyrolysis to produce mesoporous improved biochar (IBC). Sorbents structures were elucidated using CHNP/O, XRD, BET, XPS, DLS, FTIR, and pH_ZPC-titration. The IBC exhibits an improved specific surface (262.12 m²/g) and mesopore size (8.34 nm) compared to its organic precursor (r-AP), 52.53 m²/g and 3.39 nm. IBC surface is also enriched with high electron density heteroatoms (P/O/N). These unique merits of porosity and surface-active-sites improved sorption efficiency. Sorption characteristics were determined for uranyl recovery, and binding mechanisms were elucidated using FTIR and XPS. The maximum sorption capacity increased from 0.571 to 1.974 mmol/g for r-AP and IBC, respectively, roughly correlated with the active-sites density per mass. Equilibrium occurred within 60/120 min, and the half-sorption-time (t_HST) was decreased from 10.73 for r-AP to 5.48 min for IBC. Langmuir and pseudo-second-order equation fits experimental data well. Sorption is endothermic for IBC (whereas exothermic with r-AP), spontaneous, and governed by entropy change. Both sorbents show high durability over multiple-cycles with desorption efficiency >94 % over seven cycles using NaHCO₃ (0.25 M). The sorbents efficiently tested for U(VI) recovery from acidic ore leachate with outstanding selectivity coefficients.