Natural Cellulose Research Articles

Exploring eco-friendly pseudo stem fiber from the agricultural byproducts of the Alpinia purpurata plant

This study explored the potential of Alpinia purpurata pseudostems, an agricultural waste product, as a sustainable and eco-friendly source of natural fibers for the textile industry. The aim was to characterize the properties of natural cellulose fibers from the pseudostems of the Alpinia purpurata plant. The research employed water retting to extract the fibers, and the intrinsic fiber properties obtained were evaluated for their suitability in textile applications. The average length of an Alpinia purpurata fiber was 67.80 cm with a fineness value of 7.61 Tex. A bundle of Alpinia purpurata fibers was comprised of many elementary fibers. Alpinia purpurata had an irregular cross-section, with the lumen having a varied oval shape. The fibers exhibited tenacity and elongation values of 2.49 g/denier and 5.72 %, respectively, and a coefficient of friction value of 0.49. Additionally, Alpinia purpurata fibers were hygroscopic, with a moisture regain value of 11.97 %. The findings revealed that the fibers possessed notable tensile strength, moderate elongation, and high moisture regain, making them suitable for non-apparel textile products requiring durability and moisture management. While not the strongest among natural fibers, their sufficient strength and other advantageous properties demonstrated their viability for various applications. This work addressed a significant gap in the literature on the utilization of agricultural by-products, proposing Alpinia purpurata pseudostems as a sustainable alternative that aligned with environmentally responsible manufacturing practices and supported the circular economy. Future research was recommended to optimize processing techniques and explore broader applications.

Neurophilic peptide-reinforced dual-fiber-network bioactive hydrogels for spinal cord injury repair

Spinal cord injury (SCI) is a challenging central nervous system disorder that characterized by microenvironmental disturbances following injury, which can be addressed by simulating the microenvironment of the spinal cord regeneration. Herein, we report the design and synthesis of bioactive hydrogels with a dual-fiber-network (DFN) porous structure, using self-assembled peptide nanofibers (PNFs) and natural cellulose nanofibers (CNFs). A neurophilic peptide is further introduced to enhance nervous regeneration capability of the pre-prepared PNF/CNF hydrogels, which then exhibit excellent neuro-affinity, self-healing ability, biodegradability, and biocompatibility, facilitating targeted SCI repair and regeneration through the hydrogel injection. The in vitro experiments reveal that the DFN hydrogel can enhance the proliferation and migration of bone marrow mesenchymal stem cells, and induce neural stem cell (NSC) proliferation with enhanced neuronal differentiation and axonal growth. Additionally, the in vivo studies validate that the hydrogel attenuates the post-SCI inflammation, inhibits reactive astrocyte proliferation, and facilitates endogenous NSC proliferation and migration, as well as promotes neuronal growth and axonal regeneration. The potential mechanism of SCI repair is ascribed to the hydrogel-induced activation of the PI3K/AKT/mTOR pathway, which alleviates inflammatory response, inhibits excessive reactive response of glial cells, and promotes NSC differentiation into neurons. This neurophilic peptide-reinforced DFN bioactive hydrogel system, with its comprehensive approach to SCI repair, holds great potential for clinical applications.

Insight into the preparation and improved properties of cellulose citrate ester hydrogel slow-release fertilizer

The development of new fertilizers with significant water retention capacity and sustainable nutrient supplementation for arid and semi-arid regions remains an important challenge. In this study, a novel slow-release fertilizer (CCEH-SRF) based on cellulose citrate ester (CCE), which is low-cost and biocompatible, was developed using epoxy chloropropane (ECH) as a cross-linker and urea as a fertilizer. The CCEH-SRF exhibited higher water swelling (21.58 g·g−1) and water retention capacity (20.69 % in 7 days) compared to the neat cellulose hydrogel (CH). Furthermore, the CCEH-SRF demonstrated improved release performance with cumulative slow-release rates of 48.0 % at 2 hours in water, and 5.3 %, 65.9 %, and 66.7 % after 1 day, 26 days, and 35 days respectively in simulated soil column percolation assays, whereas the CH-based SRF had inferior release performance. The nutrient slow-release of CCEH-SRF followed the First-order kinetic model and Fick diffusion process accurately. Additionally, the developed CCEH-SRF showed positive growth promotion effects on maize seedlings, indicating its promising practical applicability. Therefore, this work provides a novel approach for developing environmentally friendly SRFs by utilizing natural cellulose derivatives from readily available agricultural waste in fields such as waste reuse, sustainable agriculture, and horticulture.

Printable ionic liquid modified cellulose acetate for sustainable chromic and resistive temperature sensing

Sustainable technologies and the circular economy paradigms require a reduction of waste, and therefore, research is focusing on the development of sustainable materials and devices capable of being reused, refurbished or recycled.In the present work, printable ionic liquid (IL)-based polymer composites with thermochromic properties have been developed through a more sustainable approach to mitigate the negative impact of advanced functional materials and processes. For this purpose, composite films based on a natural polymer, cellulose acetate (CA), and different contents of the thermochromic IL, bis(1-butyl-3-methylimidazolium) tetrachloronickelate ([Bmim]2[NiCl4]), have been processed by a solvent casting method for the development of sustainable temperature sensors. The composites are transparent at room temperature, but when exposed to a temperature of 50 °C, the colour changes to blue. Incorporating the thermochromic IL led to the appearance of pores in the material's structure, which increased with increasing IL concentration. Additionally, the Young Modulus decreases with increasing IL concentration, reaching a value of 840 ± 158 MPa) for the sample with 40 % wt. Contrarily, the electrical conductivity strongly increases with the highest DC electrical conductivity, with a maximum conductivity of 1.1 × 10–5 ± 1.5 × 10–6 S.cm-1 obtained for the sample with 40 % wt. of [Bmim]2[NiCl4].As a proof of concept, the potential applicability of the developed natural-based nanoparticle-free materials was demonstrated with a CA/40[Bmim]2[NiCl4] sample by the development of printable thermochromic temperature sensors for thermotherapy applications in the temperature range from 33 °C to 50 °C.

A cellulose-binding domain specific for native crystalline cellulose in lytic polysaccharide monooxygenase from the brown-rot fungus Gloeophyllum trabeum

Cellulose-binding domains (CBDs) play a vital role in cellulose degradation by enzymes. Despite the strong ability of brown-rot fungi to degrade cellulose in wood, they have been considered to lack or have a low number of enzymes with CBD. Here, we report the C-terminal domain of a lytic polysaccharide monooxygenase from the brown-rot fungus Gloeophyllum trabeum (GtLPMO9A-2) functions as a CBD, classified as a new family of carbohydrate-binding module, CBM104. The amino acid sequence of GtCBM104 shows no similarity to any known CBDs. A BLAST search identified 84 homologous sequences at the C-terminus of some CAZymes, mainly LPMO9, in basidiomycetous genomes. Binding experiments revealed GtCBM104 binds selectively to native crystalline cellulose (cellulose I), but not to artificially modified crystalline or amorphous cellulose, while the typical fungal CBD (CBM1) bound to all cellulosic materials tested. The adsorption efficiency of GtCBM104 to cellulose I was >20-times higher than that of CBM1. Adsorption tests and microscopic observations strongly suggested that GtCBM104 binds to the hydrophilic regions of cellulose microfibrils, while CBM1 recognizes the hydrophobic surface. The discovery of GtCBM104 strongly suggests that the contribution of CBD to the cellulose enzymatic degradation mechanism of brown-rot fungi is much larger than previously thought.

The impact of the carbohydrate-binding module on how a lytic polysaccharide monooxygenase modifies cellulose fibers

BackgroundIn recent years, lytic polysaccharide monooxygenases (LPMOs) that oxidatively cleave cellulose have gained increasing attention in cellulose fiber modification. LPMOs are relatively small copper-dependent redox enzymes that occur as single domain proteins but may also contain an appended carbohydrate-binding module (CBM). Previous studies have indicated that the CBM “immobilizes” the LPMO on the substrate and thus leads to more localized oxidation of the fiber surface. Still, our understanding of how LPMOs and their CBMs modify cellulose fibers remains limited.ResultsHere, we studied the impact of the CBM on the fiber-modifying properties of NcAA9C, a two-domain family AA9 LPMO from Neurospora crassa, using both biochemical methods as well as newly developed multistep fiber dissolution methods that allow mapping LPMO action across the fiber, from the fiber surface to the fiber core. The presence of the CBM in NcAA9C improved binding towards amorphous (PASC), natural (Cell I), and alkali-treated (Cell II) cellulose, and the CBM was essential for significant binding of the non-reduced LPMO to Cell I and Cell II. Substrate binding of the catalytic domain was promoted by reduction, allowing the truncated CBM-free NcAA9C to degrade Cell I and Cell II, albeit less efficiently and with more autocatalytic enzyme degradation compared to the full-length enzyme. The sequential dissolution analyses showed that cuts by the CBM-free enzyme are more evenly spread through the fiber compared to the CBM-containing full-length enzyme and showed that the truncated enzyme can penetrate deeper into the fiber, thus giving relatively more oxidation and cleavage in the fiber core.ConclusionsThese results demonstrate the capability of LPMOs to modify cellulose fibers from surface to core and reveal how variation in enzyme modularity can be used to generate varying cellulose-based materials. While the implications of these findings for LPMO-based cellulose fiber engineering remain to be explored, it is clear that the presence of a CBM is an important determinant of the three-dimensional distribution of oxidation sites in the fiber.

Hydrogen bond producers in powerful protic ionic liquids for enhancing dissolution of natural cellulose

AbstractThe manipulation of hydrogen bonding within protic ionic liquids is conducive to conquering the robust hydrogen bonding interactions in cellulose for its effective dissolution, but it is a great challenge to establish the delicate balance of hydrogen bonding network between solvent and cellulose. Herein, we proposed the concept of “hydrogen bond producers” for urea molecules in 1,1,3,3‐tetramethylguanidinium methoxyacetate acid ([TMGH][MAA]) to enhance the dissolution of cellulose. The optimization of physicochemical properties for [TMGH][MAA] solvent as a function of urea concentration revealed a remarkable increase in cellulose solubility from 13% to 17% (w/w) by adding only 0.25 wt% urea, highlighting the efficiency of [TMGH][MAA] as a powerful solvent for the dissolution of cellulose. The experimental and simulation results verified that the significant improvement on dissolution of cellulose was attributed to the hydrogen bonding interaction of urea molecules with ion pairs and part of free ions, reducing the interference with the active ions bonded to cellulose. Furthermore, the considerable enhancement on comprehensive properties of regenerated cellulose films demonstrated the effectiveness of [TMGH][MAA]/urea solvent. The concept of “hydrogen bond producers” presented here opens a new avenue for significantly enhancing the dissolution of natural cellulose, promoting the sustainable development in large‐scale processing of cellulose.

Electrovalent effects of sodium carboxymethyl cellulose and hydroxyethyl cellulose on regeneration of empty fruit bunch cellulose to a superabsorbent hydrogel

The hydrogel regeneration process, involving various cellulose types, results in distinct chemical bonding patterns. Even minor variations in chemical interactions among polymers during regeneration significantly impact properties like hydrogel-forming ability, hydrophilicity, and swelling capacity. This study focuses on regenerating a superabsorbent hydrogel from the interplay of native empty fruit bunch cellulose (EFBC), sodium carboxymethyl cellulose (NaCMC), and hydroxyethyl cellulose (HEC) using epichlorohydrin (ECH) as a crosslinker. The hydrogel was formed from dissolved EFBC solutions in an aqueous NaOH/urea solvent, supplemented with different NaCMC and HEC weight ratios, and ECH chemically assisted the crosslinking process. EFBC provides the hydrogel's supporting skeletal structure, while NaCMC and HEC play vital roles in enhancing forming ability and its physical and mechanical properties through diverse chemical interactions based on their electrovalent properties. Notably, NaCMC imparts hydrophilicity, while HEC indirectly improves superabsorbent properties through the enhancement of the elastic network's retraction force. Hydrogels combining NaCMC and HEC show a remarkable water absorption capacity exceeding 30,000 %, surpassing those regenerated solely with EFBC and NaCMC. The highest swelling, over 130,000 %, is achieved with 0.75 % NaCMC and 0.25 % HEC. Regarding thermal stability, hydrogels with a higher NaCMC proportion outperform those with increased HEC content. The study highlights the critical role of tailored chemical interactions in successfully regenerating an improved superabsorbent hydrogel with enhanced water absorption properties.

Preparation and characterization of microcrystalline cellulose from rice bran.

Rice bran, a by-product of rice processing, has not been fully utilized except for the small amount used for raising animals. The raw material source requirements of microcrystalline cellulose are becoming increasingly extensive. However, the characteristics of preparing microcrystalline cellulose from rice bran have not been reported, which limits the application of rice bran. Microcrystalline cellulose was obtained from rice bran by alkali treatment, delignification, bleaching and acid hydrolysis. The morphology, particle size distribution, degree of polymerization, crystallinity, and thermal stability of rice bran microcrystalline cellulose were analyzed. The chemical compositions, scanning electron microscopy and Fourier-transform infrared analysis for rice bran microcrystalline cellulose showed that the lignin and hemicellulose were successfully removed from the rice bran fiber matrix. The morphology of rice bran microcrystalline cellulose was shown to be of a short rod-shaped porous structure with an average diameter of 65.3 μm. The polymerization degree of rice bran microcrystalline cellulose was 150. The X-ray diffraction pattern of rice bran microcrystalline cellulose showed the characteristic peak of natural cellulose (type I), and its crystallization index was 71%. The rice bran microcrystalline cellulose may be used in biological composites with temperatures between 150 °C and 250 °C. These results suggest the feasibility of using rice bran as a low-price source of microcrystalline cellulose. © 2024 Society of Chemical Industry.

Recent Developments of Pineapple Leaf Fiber (PALF) Utilization in the Polymer Composites—A Review

Plant fibers’ wide availability and accessibility are the main causes of the growing interest in sustainable technologies. The two primary factors to consider while concentrating on composite materials are their low weight and highly specific features, as well as their environmental friendliness. Pineapple leaf fiber (PALF) stands out among natural fibers due to its rich cellulose content, cost-effectiveness, eco-friendliness, and good fiber strength. This review provides an intensive assessment of the surface treatment, extraction, characterization, modifications and progress, mechanical properties, and potential applications of PALF-based polymer composites. Classification of natural fibers, synthetic fibers, chemical composition, micro cellulose, nanocellulose, and cellulose-based polymer composite applications have been extensively reviewed and reported. Besides, the reviewed PALF can be extracted into natural fiber cellulose and lignin can be used as reinforcement for the development of polymer biocomposites with desirable properties. Furthermore, this review article is keen to study the biodegradation of natural fibers, lignocellulosic biopolymers, and biocomposites in soil and ocean environments. Through an evaluation of the existing literature, this review provides a detailed summary of PALF-based polymer composite material as suitable for various industrial applications, including energy generation, storage, conversion, and mulching films.

Synthesis of a Phosphoethanolamine Cellulose Mimetic and Evaluation of Its Unanticipated Biofilm Modulating Properties.

When coordinating and adhering to a surface, microorganisms produce a biofilm matrix consisting of extracellular DNA, lipids, proteins, and polysaccharides that are intrinsic to the survival of bacterial communities. Indeed, bacteria produce a variety of structurally diverse polysaccharides that play integral roles in the emergence and maintenance of biofilms by providing structural rigidity, adhesion, and protection from environmental stressors. While the roles that polysaccharides play in biofilm dynamics have been described for several bacterial species, the difficulty in isolating homogeneous material has resulted in few structures being elucidated. Recently, Cegelski and co-workers discovered that uropathogenic Escherichia coli (UPEC) secrete a chemically modified cellulose called phosphoethanolamine cellulose (pEtN cellulose) that plays a vital role in biofilm assembly. However, limited chemical tools exist to further examine the functional role of this polysaccharide across bacterial species. To address this critical need, we hypothesized that we could design and synthesize an unnatural glycopolymer to mimic the structure of pEtN cellulose. Herein, we describe the synthesis and evaluation of a pEtN cellulose glycomimetic which was generated using ring-opening metathesis polymerization. Surprisingly, the synthetic polymers behave counter to native pEtN cellulose in that the synthetic polymers repress biofilm formation in E. coli laboratory strain 11775T and UPEC strain 700415 with longer glycopolymers displaying greater repression. To evaluate the mechanism of action, changes in biofilm and cell morphology were visualized using high resolution field-emission gun scanning electron microscopy which further revealed changes in cell surface appendages. Our results suggest synthetic pEtN cellulose glycopolymers act as an antiadhesive and inhibit biofilm formation across E. coli strains, highlighting a potential new inroad to the development of bioinspired, biofilm-modulating materials.

A Self‐Assembled Hybrid Electrode with Efficient Tandem Electrochemistry for Dissolution‐Shielding, Ultrafast‐Charging, and Record‐Lifespan Zinc‐Ion Batteries

AbstractThe design of electrode compatible with wide‐temperature, fast‐charging, and long‐lifespan aqueous zinc‐ion batteries is a great challenge that urgently needs addressing. However, the mismatch between runaway host dissolution and high interfacial hydrophilicity within electrode is a contradictory problem that restricts their electrochemical performance. In this report, take the typical vanadium diselendie (VSe2) host for example, by employing the natural polymer bacterial cellulose (BC) as the multifunctional mediator, a design paradigm of self‐assembly hybrid electrode with efficient tandem electrochemistry is presented. Theoretical and experimental research confirmed that such BC‐mediated hybrid structure exhibits multiple functions to well balance the cathode dissolution and storage kinetics. Impressively, such an electrode displayed an excellent rate capability (1–50 A g−1), and an unexpected record‐lifespan of 45 000 cycles. Beyond that, it also shows a good temperature‐tolerance ability, remaining the high specific capacities of 120 and 288 mAh g−1 (at 10 A g−1) after 3000 cycles at −25 and 50 °C, respectively. Note that such approach is also applicable to the high‐voltage platform MnO2 and I2 hosts, demonstrating its potential for universality. This discovery can provide a new design principle of robust electrode for advanced aqueous zinc‐ion batteries.

Tough and Elastic Cellulose Composite Hydrogels/Films for Flexible Wearable Sensors.

Cellulose and its composites, despite being abundant and sustainable, are typically brittle with very low flexibility/stretchability. This study reports a solution processing method to prepare porous, amorphous, and elastic cellulose hydrogels and films. Native cellulose dissolved in a water-ZnCl2 mixture can form ionic gels through in situ polymerization of acrylic acid (AA) to poly(acrylic acid) (PAA). The addition of up to 30 vol % AA does not change the solubility of cellulose in the water-ZnCl2 mixture. After polymerization, the formation of interpenetrated networks, resulting from the chemical cross-linking of PAA and the ionic/coordination binding among cellulose/PAA and ZnCl2, gives rise to strong, transparent, and ionically conductive hydrogels. These hydrogels can be used for wearable sensors to detect mechanical deformation under stretching, compression, and bending. Upon removal of ZnCl2 and drying the gels, semitransparent amorphous cellulose composite films can be obtained with a Young's modulus of up to 4 GPa. The rehydration of these films leads to the formation of tough, highly elastic composites. With a water content of 3-10.5%, cellulose-containing films as strong as paper also show typical characteristics of elastomers with an elongation of up to 1300%. Such composite films provide an alternative solution to resolving the material sustainability of natural polymers without compromising their mechanical properties.

Loading of bacterial cellulose dressing with frutalin, a lectin from Artocarpus incisa L.

Bacterial cellulose (BC), produced by bacterial fermentation, is a high-purity material. BC can be oxidized (BCOXI), providing aldehyde groups for covalent bonds with drugs. Frutalin (FTL) is a lectin capable of modulating cell proliferation and remodeling, which accelerates wound healing. This study aimed to develop an FTL-incorporated dressing based on BC, and to evaluate its physicochemical properties and biological activity in vitro. An experimental design was employed to maximize FTL loading yield onto the BC and BCOXI, where independent variables were FTL concentration, temperature and immobilization time. BCOXI-FTL 1 (44.96 % ± 1.34) had the highest incorporation yield (IY) at the experimental conditions: 6 h, 5 °C, 20 μg mL−1. The second highest yield was BCOXI-FTL 6 (23.28 % ± 1.43) using 24 h, 5 °C, 100 μg mL−1. Similarly, the same reaction parameters provided higher immobilization yields for native bacterial cellulose: BC-FTL 6 (16.91 % ± 1.05) and BC-FTL 1 (21.71 % ± 1.57). Purified FTL displayed no cytotoxicity to fibroblast cells (<50 μg mL−1 concentration) during 24 h. Furthermore, BCOXI-FTL and BC-FTL were non-cytotoxic during 24 h and stimulated fibroblast migration. BCOXI-FTL demonstrated neutrophil activation in vitro similar to FTL. These promising results indicate that the bacterial cellulose matrices containing FTL at low concentrations, could be used as an innovative biomaterial for developing wound dressings.

Preparation of electrospun cellulose acetate/chitosan membranes for efficient sorption of heavy metals from aqueous solutions

Guided by efficient utilization of natural abundant cellulose and chitosan as separation materials, it is desired to tailor the composition of electrospun cellulose acetate/chitosan (CL/CS) membranes to achieve their optimal application in the management of aquatic heavy metal pollution. In this work, CL/CS membranes with enhanced surface area of 11.3–38.6 m2/g were successfully fabricated via electrospinning technique by dissolving cellulose acetate and chitosan into the environmental-friendly electrospinning solvent of LiOH/thiourea/H2O. Electrospun CL/CS membranes allowed the efficient sorption of Cr(VI), Pb(II) and Cu(II) with favorable kinetics (8.0 h), and excellent capacities (127.6 mg/g for Cr(VI), 66.2 mg/g for Pb(II), 46.7 mg/g for Cu(II) at pH 5.0, T 298 K). Meanwhile, they presented favorable efficiencies in the removal of these multiple heavy metals from acid simulated wastewaters. The spectroscopic analysis results indicated that the sorption mechanism should be dominant by the surface complexation of heavy metals with hydroxyl O-/amino N-species, the electrostatic attraction (protonated NH3+ with negatively charged HCrO4-, deprotonated O- with positively charged Pb(II) and Cu(II)), as well as the reduction of Cr(VI) to Cr(III) by surface reductive N-species. This work demonstrated the feasibility of electrospun CL/CS membranes as a promising choice for the remediation of aquatic heavy metals.

Exploring the phase behavior of natural egg yolk-carboxymethyl cellulose concentrate: Impact on emulsification and gelling properties

This study developed a dilution-phase diagram method to determine the phase behavior of concentrated egg yolk-carboxymethyl cellulose (EYCM). The results demonstrated that the strength of the electrostatic interaction (SEI) was within the strength limit (1314 mV2), and selective patch binding dominated the formation of soluble complexes. An SEI beyond the strength limit of electrostatic repulsion dominated the formation of alkaline co-solubility. The complex coacervates were formed due to strong electrostatic attraction at SEI > −100 mV2. The acidic co-solubility was formed due to the protonation of carboxymethyl cellulose (CMC). Spectroscopic analysis revealed that the stability of the EYCM spatial structure of the soluble complex was due to the stabilized hydrophobic core, the low content of unstable irregular coils (23.12%) and the high content of highly stabilized β-sheets (24.36%). The different phase behaviors of EYCM affected the emulsification and gelation properties. The acidic and alkaline environments led to co-solubility of the EYCM of a smaller particle size (<362.7 nm), which exhibited a better emulsifying activity. A suitable particle size and depletion attraction improved the emulsification activity and stability of the soluble complexes. Although the complex coacervates had a larger particle size (4160.1 nm), the free CMC-induced depletion attraction contributed to the favorable emulsion stability. In addition, for alkaline co-solubility, the intermolecular folding of LDL, lipid filling and CMC enhancement of the gel framework to form a strong gel. As acidification proceeded, protein unfolding was restricted, the role of lipids and CMC was reduced, and the gel structure gradually diminished.

Synergistic Effect of UiO-66 Directly Grown on Kombucha-Derived Bacterial Cellulose for Dye Removal.

Metal-Organic Frameworks (MOFs) are particularly attractive sorbents with great potential for the removal of toxic dye pollutants from industrial wastewaters. The uniform dispersion of MOF particles on suitable substrates then represents a key condition to improve their processability and provide good accessibility to the active sites. In this work, we investigate the efficiency of a natural bacterial cellulose material derived from Kombucha (KBC) as an active functional support for growing and anchoring MOF particles with UiO-66 structures. An original hierarchical microstructure was obtained for the as-developed Kombucha cellulose/UiO-66 (KBC-UiO) composite material, with small MOF crystals (~100 nm) covering the cellulose fibers. Promising adsorption properties were demonstrated for anionic organic dyes such as fluorescein or bromophenol blue in water at pH 5 and pH 7 (more than 90% and 50% removal efficiency, respectively, after 10 min in static conditions). This performance was attributed to both the high accessibility and uniform dispersion of the MOF nanocrystals on the KBC fibers together with the synergistic effects involving the attractive adsorbing properties of UiO-66 and the surface chemistry of KBC. The results of this study provide a simple and generic approach for the design of bio-sourced adsorbents and filters for pollutants abatement and wastewater treatment.

Isolation of Highly Crystalline Cellulose via Combined Pretreatment/Fractionation and Extraction Procedures within a Biorefinery Concept.

Sustainable production of bio-based materials and chemicals requires integrated approaches which utilize all fractions of lignocellulosic biomass. In this work, highly crystalline cellulose was isolated via combined pretreatment/fractionation and extraction processes from beechwood sawdust. The proposed approach was based on the selective recovery of hemicellulose components in the first step, followed by enhanced delignification in the second step, permitting the efficient recovery of the remaining cellulose via bleaching in the final step. Hydrothermal pretreatment under tailored conditions in neat water or dilute acid resulted in almost complete hemicellulose removal (80-96 wt %) in the liquid fraction. In the second step, the formed surface lignin was isolated via mild extraction while enhanced removal of both native/structural and surface lignin (71 wt %) was achieved by applying the organosolv treatment using dilute sulfuric acid as catalyst. Dilute sulfuric acid pretreatment followed by acid catalyzed organosolv pretreatment proved to be the most efficient combined approach, leading to 80 wt % hemicellulose removal as xylose monomer, and 71 wt % delignification. High crystallinity cellulose (<88%), with an overall cellulose recovery of 68-91 wt % based on native cellulose in parent biomass was isolated in the last step via bleaching of all pretreated biomass solids. The proposed integrated biorefinery procedures that aim to whole "waste" biomass valorization, replacing fossil resources, with the use of green solvents (water, ethanol) at relatively mild temperature/pressure conditions, are in line with the scope of several United Nations Sustainable Development Goals, such as UN SDG 8, 11, 12, and 13.

Concentration-dependent bacterial cellulose patches: a strategy for modulating the drug release beyond the modifications of the native cellulose hydrogel

Concentration-dependent bacterial cellulose patches: a strategy for modulating the drug release beyond the modifications of the native cellulose hydrogel

In situ alkali‐free growth of octahedral Ag2O nanoparticles by bacterial cellulose for efficient antibacterial application

AbstractUniform octahedral Ag2O nanoparticles were in situ synthesized within natural bacterial cellulose (BC) films without any inorganic alkali. The morphological transformation of Ag2O from nanoparticles and small nanoplates to an octahedral structure was well controlled by varying the UV exposure time. To reduce and anchor Ag2O nanoparticles, abundant hydroxyl groups on the surface of natural BC fibers ensured an ideal environment for the mild redox reaction between Ag+ and –OH groups. The structural features and structure–activity relationship of Ag2O/BC films were confirmed through TEM, energy dispersive spectroscopy assisted SEM analysis, Fourier transform IR, X‐ray photoelectron spectroscopy, TGA and XRD. The structure–antibacterial activity relationship of the Ag2O/BC films was proved against both Gram‐positive (Staphylococcus aureus) and Gram‐negative (Escherichia coli) bacteria. They also showed excellent performance in the photocatalytic degradation of organic dyes. Ag2O/BC films have potential bactericidal applications in the field of pharmacy, specifically for wound dressing and flexible wearable materials. © 2024 Society of Chemical Industry.