In this study, we present a simple and reproducible strategy for the fabrication of self-assembled lignin nanoparticles (LNPs) using enzymatic lignin derived from corncob biomass. Despite the sustainable nature of lignin, its poor dispersibility, aggregation tendency, and limited formulation compatibility remain major challenges for practical cosmetic and UV-shielding applications. To address these limitations, LNPs were prepared via a solvent-exchange dialysis process driven by intermolecular interactions and solvent polarity shifts. The antioxidant activities of the prepared LNPs exhibited a concentration-dependent trend. The half maximal inhibitory concentration decreased from 115.55 mu g/mL to 51.80 mu g/mL with increasing lignin concentration, approaching the performance of the commercial antioxidant butylated hydroxytoluene. When LNPs were added to a cosmetic lotion formulation, they provided UV protection in both the UV-A and UV-B spectra. The UV-B protection rate increased from 61.6% (base cream) to 72.0%, 67.9%, and 71.9% with LNP contents of 1%, 5%, and 10%, respectively. Similarly, the UV-A protection rate increased from 26.4% to 40.8%, 36.3%, and 38.4%, representing improvements of 54.8%, 37.6%, and 45.5%, respectively. These results demonstrate that LNPs not only improve the dispersibility and functional performance of lignin-based formulations but also exhibit strong potential as sustainable and eco-friendly UV-shielding materials for cosmetic applications.
A mechanistic understanding of kraft delignification remains incomplete, particularly regarding the role of hydrogen sulfide in the reaction kinetics. This work examines its influence from both mechanistic and kinetic perspectives. Laboratory-scale kraft cooks on birch wood meal were conducted in a flow-through reactor, providing two main advantages: (i) continuous sampling of the immediately cooled cooking liquor, enabling snapshots of dissolved components throughout the cook, and (ii) rapid adjustments of the liquor composition, enabling kinetic evaluation without a priori assignment to simplified rate constants. The sulfide dependency was found to cease partway through the process, persisting longer than expected from the reactions typically considered to control delignification, while simultaneously indicating that said reactions are unlikely to control the rate throughout the entire process. Furthermore, significant and previously unreported differences in the molecular weight distribution between kraft and soda lignin were observed. These differences were further investigated through transient experiments and 2D NMR analysis. The results suggest that HS- also enhances the delignification rate by the more extended demethylation occurring during kraft pulping, thereby enabling larger fractions of dissolved lignin to be removed compared with soda pulping.
This study investigated the competence of residue materials from paper processing, known as fibrous sludge waste (FSW), as a wood residue substitute for particleboard manufacturing using eco-friendly citric-sucrose (CS)-based adhesives. FSW was used as a replacement at various substitution levels (0%, 50%, 75%, and 100%) using the CS adhesive. The mechanical and physical properties at pressing temperatures of 180 degrees C, 200 degrees C, and 220 degrees C were investigated. Additionally, this study also compared the CS adhesives and tannin additional adhesive (commercial tannic acid and tannin extracted from neem leaves) to enhance the water resistance of particleboard. The results showed that the FSW fiber could substitute wood residues up to 100% (FSW100), which had optimal condition mechanical properties at pressed 200 degrees C when compared with the FSW0 (100% wood residues) at 220 degrees C. Moreover, the addition of extracted tannin to FSW100 reduced water absorption after 24 h of being submerged in water. Furthermore, the results revealed the presence of inorganic compounds in FSW, confirmed by SEM examination with EDS and XRF, including inorganic compound distribution by SR-XTM. This research demonstrates the possibility of using FSW to substitute 100% of wood and contribute to waste valorization and sustainability in the wood-based panel industry.
Fabricating highly durable, lightweight, toxicity-free, waterproof, antimicrobial, and flame-resistant biocomposite-based plant fibers has become a very promising way to achieve sustainability, enabling the use of these materials in a vast range of applications. Thus, this manuscript aimed to develop sustainable composites based on the incorporation of natural Nile rose fibers (NRFs) (named Eichhornia crassipes) inside low-density polyethylene (LDPE), facilitated by antimicrobial natural gum rosin acids (R) as a coupling agent to be used as plastic-wood biocomposites (PWBCs). A series of characterizations and measurements was conducted for LDPE biocomposites (LDPE/R-NRFs), including mechanical, morphology, hydrophobicity assessed by thickness swelling, flammability evaluated by the needle flame method, and antibacterial properties. The findings from mechanical testing illustrated that the tensile stress for LDPE/R-NRFs 20% jumped to 29.80 MPa compared to neat LDPE (20.60 MPa), whereas it dropped to 18.30 MPa at high NRFs fiber quantity (40 wt.%). This outcome was confirmed by SEM observations. The final impact on flammability and antibacterial properties was verified, and their data exhibited that superior flame-resistant and antibacterial activity achieved; the flammability for LDPE/R-NRFs 40% was delayed, with no smoke emission during the experiment time (120 s), while the halos of inhibition were obviously observed for all biocomposites with variable diameters ranging from 23 to 33 mm.
The increasing global demand for biodegradable and environmentally sustainable materials has driven significant interest in natural fibers as alternatives to synthetic reinforcements. In this context, the present study provides a comprehensive characterization of Canavalia ensiformis stem fiber as a multifunctional reinforcement for green composite development. Detailed analyses, including mechanical, thermal, structural, chemical, morphological, and antibacterial evaluations, were conducted to assess its suitability for sustainable applications. The fiber exhibited a tensile strength of 6.89 MPa and an elongation at break of 0.034, indicating moderate strength with good ductility, suitable for flexible and impact-absorbing composites. SEM analysis revealed continuous fiber bundles with minimal surface impurities, supporting effective matrix adhesion. X-ray diffraction indicated a predominantly amorphous structure (86.2%), influencing flexibility and mechanical behavior. FTIR analysis confirmed the presence of cellulose, hemicellulose, and lignin, validating its lignocellulosic nature and compatibility with polymer matrices. Thermogravimetric analysis showed a major degradation phase between 300-400 degrees C with around 40% char residue, demonstrating adequate thermal stability for composite processing. The antibacterial study revealed a significant inhibition zone against Escherichia coli (17 mm at 60 & micro;g), comparable to Streptomycin (16 mm at 10 & micro;g). Confocal laser scanning microscopy further confirmed reduced biofilm formation and membrane disruption.
Efficient conversion of lignocellulosic biomass into fermentable sugars is critical for sustainable bioenergy production. This study reports the production and comprehensive characterization of a robust cellulase system from Penicillium citrinium LHB3 using agro-wastes under solid-state fermentation. Maximum enzyme production was achieved at 30-50 degrees C, pH 3-8, and 60-80% moisture, with cassava peel supporting the highest yield. The cellulase components (FPase, endoglucanase, and beta-glucosidase) exhibited optimal activities between 40-60 degrees C, with distinct pH optima of 10, 11, and 3, respectively. Notably, FPase demonstrated remarkable stability, retaining 63-83% activity across 30-80 degrees C after 2 h and 50-70% residual activity between pH 2 and 12 after 6 h. Enzyme activity was enhanced by metal ions (Ca2+, Al & sup3;+, Zn2+, Hg2+) and organic solvents, with minimal inhibition at 5 mM of common inhibitory agents. Substrate pretreatment using H2SO4, NaOH, and hot water (60 degrees C) significantly improved saccharification efficiency. The crude enzyme achieved up to 70% sugar release from coconut husk after 9 h, and 61% for cocoa pod and cassava peel after 6 h, underscoring its strong hydrolytic capacity. These findings highlight the biochemical robustness and industrial relevance of the P. citrinium LHB3 cellulase for efficient valorization of agro-waste and biofuel production.
Bamboo and wooden artifacts unearthed in archaeological excavations often shrink, warp or crack due to rapid moisture loss. Conventional moisturizing methods, such as physical wrapping or pure glycerol solutions, are cumbersome, show limited moisture retention, or risk structural damage. Here, a glycerol-based microemulsion is developed for aged bamboo artifacts, composed of Tween 80/Span 80 (4:1), liquid paraffin and a 50% glycerol aqueous solution. Five surfactant-to-oil ratios (9:1-5:5) are evaluated on artificially aged bamboo strips produced by 120 dry-wet cycles. Moisturizing ability increases with oil fraction, and the S7-P3 formulation (7:3) shows the best performance: it reduces hourly moisture loss by similar to 70%, maintains >70% water after 24 h at 60 degrees C, and decreases the water contact angle to 23.4 degrees. This behavior results from a synergistic mechanism in which surfactants promote uniform spreading, glycerol slows evaporation via hydrogen bonding, and liquid paraffin acts as a bulking agent to provide structural support. The treatment does not alter cellulose, hemicellulose or lignin, while color change (Delta E* = 4.7), dimensional change (<1%) and bending strength remain within the minimum-intervention range. The proposed microemulsion provides a practical strategy to prevent cracking in bamboo artifacts during excavation.
Plant fiber paper has poor water resistance due to high cellulose and hemicellulose content. In this study, it was modified with biodegradable natural rosin. Maleic rosin polyvinyl alcohol ester was synthesized and analyzed using Minitab. Carboxylated cellulose nanocrystals (CNCs), known for high strength, stiffness, and biodegradability, were employed as an emulsifier to prepare a stable maleic rosin ester emulsion. The optimal synthesis conditions for maleic rosin ester are a 1:3 molar ratio of maleic rosin to polyvinyl alcohol, along with 1% catalyst and 0.4% initiator, at 220 degrees C. The resulting emulsion has an average particle size of 406 nm and remains stable at room temperature for 90 days. The double-layer coated paper made with this emulsion exhibits super-hydrophobic properties, with a water contact angle of 160 degrees. It maintains these properties after 50 friction cycles and 300 folds. These findings indicate that superhydrophobic paper holds great potential as a sustainable alternative to plastic materials.
In this study, cellulose nanofibers (CNFs) were isolated from Eucalyptus wood pulp (WP) using a chemo-mechanical method that involved sulfuric acid treatment, cryocrushing, and ultrasonication. To minimize environmental impact and reduce chemical usage, a low concentration of sulfuric acid was employed to isolate nanofibers. The isolation process was optimized using 5% and 10% (w/w) sulfuric acid solutions, followed by varying durations of cryocrushing and ultrasonication to produce CNFs. The resulting CNFs were characterized using light microscopy, scanning electron microscopy (SEM), attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), and X-ray diffraction (XRD) to evaluate their morphology, chemical composition, and crystallinity. The FTIR results showed that lignin and hemicellulose were effectively removed from the isolated cellulose nanofibrils. XRD analysis revealed that the crystallinity index (CrI) was increased from wood pulp (WP) to bleached wood pulp (BWP), but the decrease observed for CNFs might due to break down of the hydrogen bonds. All treatments successfully produced CNFs, which exhibited diameters ranging from 9.23 to 47.51 nm. The findings of this study suggest that the combination of acid hydrolysis, liquid nitrogen-assisted cryocrushing, and ultrasonication is an effective chemo-mechanical process to disrupt the cellulose matrix to produce nanofibers.
The thermal modification alters the physical-chemical and mechanical properties of wood, potentially increasing its natural durability. Based on this, the objective of this study was to analyze the effects of thermal modification on wood from Eucalyptus grandis W. Hill ex Maiden & times; Eucalyptus urophylla S. T. Blake clones and its impact on chemical properties and biological resistance against drywood and subterranean termites. Wood samples from each clone were subjected to a heating ramp up to 185 and 200 degrees C. Chemically, the ash content (%) and total extractives (%) were analyzed. Biological resistance was assessed through choice feeding and no-choice feeding tests with drywood and subterranean termites. The parameters evaluated included mass loss, wood damage, number of holes (drywood termites), and termite mortality (no-choice feeding). After thermal modification, a decrease in total extractive content was observed. As for ash content, clone C showed an increase, while clone E presented a reduction. In the choice feeding tests with both termite groups, the samples thermally modified at 185 degrees C were the most consumed. In the no-choice feeding tests with drywood termites, clone C showed lower mass loss and fewer holes compared to clones A and E. It was concluded that thermal modification at the tested temperatures (185 and 200 degrees C) made the wood of E. grandis & times; E. urophylla clones more susceptible to attack by drywood and subterranean termites.
Delignification with sodium chlorite in water at pH 4-5 and 70-80 degrees C for 1 h (Wise method) was applied to metasequoia 3, 5, and 7 times, and bamboo 3 and 5 times. Neutral sugar compositions, solid-state 13C-NMR spectra, X-ray diffraction (XRD) patterns, and molar-mass parameters of these samples were analyzed to study their structural changes by the number of NaClO2-treatment cycle. Metasequoia samples contained mannose and xylose at similar to 1:1 as hemicellulose components, while xylan was the major hemicellulose in bamboo as in the case of other angiosperms. The XRD patterns of bamboo samples were slightly different from those of metasequoia samples. The signal peak positions of C6 carbons with trans/gauche conformations of cellulose I and crystalline C4 carbons in solid-state 13C-NMR spectra of bamboo samples were slightly different from those of metasequoia samples, which may be related to the different crystal structures of cellulose I between metasequoia and bamboo. After stirring the original and NaClO2-treated metasequoia and bamboo samples in 8% LiCl/DMAc for 4 wk, the molar mass parameters of the samples were obtained by size-exclusion chromatography (SEC). The mass-average degrees of polymerization of NaClO2-treated metasequoia samples were similar to 3,000, and those of bamboo samples were similar to 2000. Residual lignin fragments were present in the high-molar-mass cellulose-rich fractions; the chemical linkages of cellulose/residual lignin fragments were present in the NaClO2-treated samples. When stirring time of the sample mixtures or solutions in 8% (w/v) LiCl/DMAc was extended to 6 months, not only depolymerization but also other side reactions occurred on cellulose and hemicellulose molecules in the samples.
Water hyacinth (WH), as an aquatic weed with high cellulose and low lignin content, presents a promising source for bioethanol production, addressing energy demands and environmental concerns. Its utilization involves pretreatment processes to break down cellulose into fermentable sugars, which can then be converted into ethanol, offering a sustainable alternative to traditional biofuel sources like starch and sugar-based crops. This approach helps mitigate issues related to food security and promotes environmentally friendly energy solutions by leveraging lingo-cellulosic biomass that does not compete with food supplies. The study successfully optimized water hyacinth hydrolysis for biofuel production by utilizing ideal conditions such as 500-watt microwave power, 1.5% NaOH concentration, and a 30-minute residence period, resulting in a high reducing sugar concentration of 347.25 mg/g, which is crucial for efficient fermentation and ethanol yield. The research achieved a bioethanol yield of 14.16 g/l by optimizing fermentation conditions using Design Expert software, with ideal parameters of 33.5 degrees C, pH 5.3, and 62 h of incubation. This approach drive water hyacinth, an invasive plant, to enhance biomass processing and fermentation efficiency, providing a sustainable solution that addresses ecological challenges while promoting renewable energy production.
Efficient bioconversion of cellulose is a remaining technical barrier for the hydrothermal pretreatment of poplar. To address it, a combined method involving PFI refining and enzymatic additive was developed to enhance the enzymatic digestibility of hydrothermally pretreated poplar in this study. The effects of the PFI refining sequence and intensity on the enzymatic digestibility of hydrothermally pretreated poplar were also discussed. Results showed that sequential hydrothermal pretreatment and PFI refining were more effective in enhancing the glucose yield of poplar from 23.7% to 55.6%. This improvement was due to the alleviating effects of PFI refining on both lignin-derived physical blockage and its complex crystalline structure of cellulose. Furthermore, the combination of PFI refining and polyethylene glycol (PEG) 6000 addition achieved a 3.39-fold increase in glucose yield of hydrothermally pretreated poplar. These findings provide a strategy for the efficient enzymatic bioconversion of hardwood after hydrothermal pretreatment.
The increasing demand for eco-friendly alternatives to conventional polymer-based food packaging materials has driven the development of biodegradable materials. Notably, films prepared from tapioca and potato starches have significant mechanical, water resistance, and thermal properties. However, their inherent brittleness, low durability, and poor barrier properties limit practical applications. In this study, potato-tapioca starch-oil-based films reinforced with cellulose derived from cotton linter were prepared and characterized. The incorporation of cotton linter cellulose (CLC) significantly enhanced the thermo-mechanical properties while reducing water solubility, moisture absorption, and CO2 permeability. The biopolymer film reinforced with 0.1 g CLC/g starch (S5) exhibited the lowest water solubility (7.01%), water vapor permeability (WVP) (4.19 x 10-5 g s-1 m-2 Pa-1), and the CO2 permeability (2.46 x 10-10 kg m-1s-1). The film reinforced with 0.08 g CLC/g starch (S4) exhibited improved mechanical strength (5.50 MPa) and Young's modulus (17.77 MPa), along with the lowest moisture absorption (12.85%). The optical properties, functional groups, morphology, surface characteristics, and thermal stability of the films were analyzed using UV-Vis spectroscopy, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), contact angle measurements, and thermogravimetric Analysis (TGA), respectively. Overall, the cellulose-reinforced films exhibited superior mechanical strength, thermal stability, and barrier properties, indicating their strong potential for sustainable food packaging applications.
The demand for sustainable materials has increased interest in natural fiber-reinforced composites as eco-friendly alternatives to synthetic counterparts. Among them, Agave sisalana (sisal) offers excellent mechanical properties and availability, but poor interfacial adhesion between untreated fibers and polymer matrices limits its reinforcing potential. This study investigates the effect of alkali treatment on the physicomechanical and interfacial adhesion of sisal fiber-reinforced unsaturated polyester composites. Sisal fibers were treated with 5% NaOH for 0, 2, and 4 h prior to composite fabrication. The 2-h treatment yielded the best performance, resulting in a tensile strength of 413.7 MPa, interfacial shear strength of 24.2 MPa, and composite tensile shear strength of approximately 35 MPa. FTIR analysis confirmed hemicellulose removal through the disappearance of the 1735 cm-1 carbonyl peak, while SEM images revealed a cleaner, rougher surface that enhanced matrix adhesion. However, excessive treatment (4 h) led to surface degradation and reduced performance. Overall, moderate alkali treatment significantly improves interfacial bonding and mechanical strength, making sisal fiber more suitable for polyester-based composite applications.
This study evaluated the potential of wood vinegars produced in C & ocirc;te d'Ivoire as natural preservatives for non-durable woods against wood-rotting fungi and subterranean termites. Wood vinegars were obtained by slow pyrolysis of selected tropical wood mixtures, chosen based on their local availability and traditional use. Four formulations were produced: WCV1 from colatier, framire, rubber wood, acacia, and abale; WCV2 from colatier, framire, rubber wood, and acacia; WCV3 from colatier, rubber wood, and dabema; and WCV4 from iroko, mahogany, and frake. The vinegars were first screened for antifungal activity using a microplate assay against six wood-decaying fungi (Trametes versicolor, Pleurotus ostreatus, Pycnoporus sanguineus, Coniophora puteana, Rhodonia placenta, and Gloeophyllum trabeum). Based on their high antifungal performance, WCV1 and WCV3 were selected for preservation tests. These vinegars were used to impregnate three non-durable wood species (Kapok, Scots pine, and Beech) selected for their contrasting densities and anatomical structures. The chemical composition of untreated woods was determined, and changes induced by impregnation were analyzed using FT-IR spectroscopy. Results showed that WCV1 and WCV3 were the most effective vinegars against wood-rotting fungi. Chemical analyses indicated lignin-rich Kapok and holocellulose-rich Scots pine, while FT-IR spectra revealed esterification reactions between wood polymers and vinegar constituents, leading to reduced hydrophilicity and improved durability. Extract retention was strongly influenced by vinegar concentration and wood density. In vitro decay and termite resistance tests demonstrated enhanced durability of treated woods, particularly Beech, while Kapok and Scots pine showed improved resistance mainly when treated with undiluted (100%) vinegars. Among all formulations, WCV3 exhibited the highest protective efficacy, attributed to its high dry matter content, confirming the potential of wood vinegars as sustainable and environmentally friendly alternatives to conventional wood preservatives.
This research investigates creating sustainable particleboards using natural fibers as affordable resources. Bamboo shavings (BS), a byproduct from furniture manufacturing, and water hyacinth (WP), an invasive aquatic plant, served as raw materials. The boards were produced by mixing BS and WP in different ratios (0-100%) and bonding them with castor oil-based polyurethane adhesive. To improve fire resistance, a bio-based flame-retardant system was added, using water hyacinth as a carbon source. Mechanical tests showed that BS100 panels had the highest modulus of elasticity (9,803 MPa) and internal bond strength (0.68 MPa), whereas WP-rich panels (>= 75%) had lower values, with MOE as low as 4,266 MPa and IB strength at 0.30 MPa. Only BS100, WP25, and WP50 panels met EN 312 (Type P5) standards for load-bearing use. Fire tests revealed that panels with water hyacinth achieved a UL94 V-0 rating, indicating good flame-retardant properties. Increasing WP content decreased the net heat of combustion, thus enhancing fire safety, while higher BS content boosted structural strength. Overall, 50% WP provided an optimal balance, offering improved flame resistance with adequate mechanical performance. This study emphasizes the potential of utilizing waste bamboo and invasive species to develop eco-friendly, fire-resistant building materials. [GRAPHICS]
The growing need for materials that are sustainable and biodegradable has resulted in the interest in composites made of natural fibers reinforced. The present study is concerned with the production of eco-friendly biocomposites made from areca fibers incorporated into a Poly Lactic Acid (PLA) matrix. The fibers were chemically modified with sodium hydroxide at 5%, 10%, and 15% concentration, and they also received a dual-treatment consisting of 5% sodium hydroxide and 2% silane to improve the bonding between the fiber and the matrix. The creation of the composites was performed through the process of compression molding at 180 degrees C and 5-10 MPa, followed by standard conditioning for mechanical and physical testing. The dual-treated composites showed the greatest development. The untreated composite tensile strength increased from 32 to 85 MPa, which is 165% increase. The impact resistance rose from 12 to 23 KJ/m2, giving a percentage gain of 91.7%. The flexural strength increases from 91 to 98 MPa, and the flexural modulus has reached 7500 MPa at 5% fiber loading. The modulus of elasticity was also increased by the same technique from 21 to 31 MPa. The physical properties underwent noticeable improvements as well. The hydrophobic silane treatment caused a decrease in water absorption from 9% to 7%. The hardness of the alkali-treated fibers increased from 80 to 85 BHN. The SEM analysis demonstrated roughness of the surface and bonding at the interface were improved. The findings support the notion that chemical treatments are effective in enhancing the performance characteristics of PLA composites with areca fibers.
