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Highlights: [•] Reaction between lignin model compound and ClO2 is researched by UV–vis. [•] Reaction mechanism of lignin model compound oxidation by ClO2 is derived. [•] Kinetics for lignin model compound oxidation by ClO2 is propose. [•] Bring new door open for resolving the environmental pollution in ECF bleaching. [ABSTRACT FROM AUTHOR]

Lignin nanoparticles (LNPs), as one of green and sustainable biological macromolecules, have attracted great attention owing to their promising potentials in many valorized fields. However, the lignin heterogeneity seriously restricts the controllable preparation of LNPs. Herein, a facile nanogrinding activation combining anhydrous ethanol dissolution process was developed to efficiently homogenize lignin prior to gradient ethanol fractionation. Two lignin fractions were obtained from nanogrinding activation/ethanol dissolution followed by gradient ethanol fractionation: L-fractions and S-fractions. Therefore, monodispersed LNPs with unique concave hollow nanostructure and large particle size, and monodispersed LNPs with solid core nanostructure and small particle size were successfully prepared from L-fractions and S-fractions, respectively, via a GVL/water anti-solvent method. The proposed LNPs formation mechanisms facilitated by nanogrinding activation/ethanol dissolution treatment were demonstrated. This study put forwards a facile and green integrated approach for monodispersed LNPs preparation with controllable morphology and particle size. [Display omitted] • Nanogrinding/ethanol treatment facilitates lignin cleavage and fractionation. • The synergistic effect fractionates lignin into L- and S- fractions. • L-/S-fractions possess unique functional groups and molecular distributions. • Monodispersed LNPs with concave hollow and core nanostructures are prepared. • The proposed mechanisms of LNPs formation are demonstrated. [ABSTRACT FROM AUTHOR]

Processing lignin into super-hydrophilic graphite by room-temperature chemical carbonization. [Display omitted] • Room-temperature carbonization has cost-effective and eco-friendly features. • Room-temperature carbonization afforded an 87% graphite yield. • Lignin-derived graphite has super-hydrophilicity. • Graphite-encapsulated liquid metal patterns have superb conductivity of 4.9 × 106 S/m. A cost-effective, and low-energy room-temperature cascade catalytic carbonization strategy is demonstrated for converting lignin into graphite with a high yield of 87 %, a high surface potential of −37 eV and super-hydrophilicity. This super-hydrophilic feature endows the lignin-derived graphite to be dispersed in a variety of polar solvents, which is important for its future applications. Encapsulating of liquid metals with the graphite for electrical circuit patterning on flexible substrates is also advocated. These written patterns show superb conductivity of 4.9 × 106 S/m, offering good performance stability and reliability while being repeatedly stretched, folded, twisted, and bent. This will offer new designs for flexible electronic devices, sensors, and biomedical devices. [ABSTRACT FROM AUTHOR]

• Residual lignin as reducing agents and stabilisers to embed Ag into lignocellulose matrix in situ. • Hybridization of coarse and fine fibers to balance pressure drop and filtration efficiency. • The self-charging enhancement boasts impressive submicron particle removal (99.70%). • The filter displayed consistent performance and durability in high humidity conditions of 80% RH. The moisture sensitivity and structural defects found in natural cellulose materials limit their ability to serve as substitutes for petroleum-based masks. This study uses a combination of methods, including retaining lignin, embedding silver particles in situ, and using a mixture of coarse and fine fibers to enhance the wet resistance, antibacterial properties, and triboelectric output of lignocellulosic materials. This approach also aimed to balance pressure drop and filtration efficiency. A triboelectric filter (Ag-LCTEF) using a perforated fluorinated ethylene propylene (FEP) film sandwiched between two sheets of Ag-embedded lignocellulose (Ag-LC) was assembled. The resulting Ag-LCTEF enabled self-powered continuous monitoring of breathing signals, boasting impressive submicron particle removal (99.70 %) and antibacterial efficiency (99.18 %), all while maintaining a relatively low-pressure drop of 76 Pa. Notably, the Ag-LCTEF displayed consistent performance and long-term durability even in high humidity conditions of 80 % RH. These remarkable achievements have spurred the suggestion of integrating respiratory protection, monitoring, and diagnostic functions, showcasing its potential for the next generation of wearable electronics. Moreover, naturally safe and biodegradable lignocellulose serves as an environmentally friendly replacement for petroleum-based materials. [ABSTRACT FROM AUTHOR]

Tobacco based cellulose nanofiber (TCNF) is a novel nanocellulose that has recently been used to replace undesirable wood pulp fibers in the preparation of reconstructed tobacco sheets (RTS). However, given the strict requirements for controlling toxic chemical content in tobacco products, there is a global interest in developing a green, efficient, and toxic-chemical free approach to isolate TCNF from tobacco stem as a bioresource. In this study, we propose a creative and environmentally friendly method to efficiently and safely isolate TCNF from tobacco stem pulp, which involves integrated biological pretreatment followed by a facile mechanical defibrillation process. Feruloyl esterase is used to pretreat the stem pulp by disrupting the ether and ester bonds between lignin and polysaccharide carbohydrates within the fiber wall, which effectively facilitates cellulase hydrolysis and swelling of the stem pulp fiber, as well as the following mechanical shearing treatment for TCNF isolation. The results demonstrate that TCNF obtained by the comprehensive feruloyl esterase/cellulase/mechanical process exhibit uniform and well-dispersed nanofiber morphology, higher crystallinity, and stronger mechanical properties than those of the control. The addition of 0.5 % TCNF can replace wood pulp by 18 wt% ~ 25 wt% in the production of RTS samples while maintaining their reasonable strength properties. [Display omitted] • A green, efficient and toxic-chemical free integrated method for TCNF preparation was proposed. • Feruloyl esterase facilitates cellulase hydrolysis efficiency of tobacco stem pulp pretreatment. • The synergistic effects of feruloyl esterase/ cellulase system facilitate TCNF isolation. • TCNF performs desirable particle size, morphology and surface charge properties. • TCNF can improve the mechanical properties of RTS by replacing 7 % wood pulp. [ABSTRACT FROM AUTHOR]

The lignin-derived inhibition on cellulase is the most critical bottleneck that must be addressed when converting lignocellulosic biomass through the sugar-platform process. Herein, a novel modified cellulase with high activity, great stability and excellent lignin-resistant ability was synthesized by chemical modification using hydrophilic and negatively charged polyethylene glycol (PEG) derivatives including HO-PEG-COOH and HOOC-PEG-COOH. Both modifications obviously increased the cellulase activity, with 37% (HO-PEG-COOH modification) and 53% (HOOC-PEG-COOH modification) increase, respectively. In addition, the stabilities of both modified cellulases were significantly enhanced, seeing from their much higher activities at all selected temperatures and pH values. The modification resulted in a movement of tryptophan residues to the exterior of enzyme, allowing the substrate chains to be more easily recruited and thus initiating the hydrolysis. The compactness of secondary structure for enzyme was improved, especially, the α-helix content was increased which requires strong hydrogen bonding to generate it, thus enhancing the stability. High hydrophilicity, negative charge and compactness of enzyme conferred modified cellulase good ability to resist lignin adsorption and destruction, thus improving the enzymatic hydrolysis of corn stover. [Display omitted] • Cellulase activity is significantly improved by up to 52% after chemical modification. • The migration of Trp residues allows the hydrolysis to be more easily initiated. • High compactness gives modified cellulase great stability and low level of damage by lignin. • High hydrophilicity and negative charge of modified cellulase prevent lignin adsorption. • The novel modified cellulase exhibits promising potential in converting corn stover. [ABSTRACT FROM AUTHOR]

Global liquid packaging industry has been greatly spurred by the rapidly growing food & beverage industry all over the world. Liquid packaging board (LPB), as the main composition (75–80 %) of laminated liquid packaging cartons, must possess high-quality of hydrophobicity and physical properties for excellent leak-proof and protecting the packaged commodity. Herein, in this study, lignin is selected to prepare lignin cationic surfactant (LCS) by quaternary ammonium modification. Then cationic lignin modified rosin size (L -CDRS) with uniform microsphere structure and high colloidal stability is successfully synthesized via a phase inversion process to improve the sizing performance and mechanical properties of LPB. The cation modified LCS presents improved amphipathicity of rich cationic charges and hydrophobic benzene ring skeleton, thus enhancing the electrostatic interactions between LCS and pulp fibers and improving the sizing performance of L -CDRS. The sizing performance of LPB is evaluated by varying the LCS dosages within L -CDRS and concluded that the edge penetration value and Cobb value of LPB handsheets exhibit an improved size performance with 2 % LCS within L -CDRS, implying the formation of homogeneous hydrophobic surface layer induced by the well-distribution of L -CDRS. In addition, the tensile index of LPB increased from 19.74 N·m/g to 25.96 N·m/g assisted by 2 % LCS emulsified L -CDRS, indicating an improved mechanical property. This study puts forward a practical and facile strategy to improve the sizing performance and mechanical properties facilitated by lignin enhanced rosin size and will further broaden the application range of traditional rosin size and lignin in LPB products. [Display omitted] • Lignin was modified into quaternary ammonium etherified cationic surfactant with improved emulsifying ability. • Cationic lignin can emulsify rosin to prepare L -CDRS with uniform microsphere structure and high colloidal stability. • L -CDRS exhibited a significantly improved sizing performance of LPB compared with the control rosin size. • The addition of L -CDRS contributed greatly to the enhanced mechanical properties of LPB. • The mechanism of improved sizing performance and mechanical properties of LPB induced by L -CDRS size agent was proposed. [ABSTRACT FROM AUTHOR]

The preparation of carbon quantum dots (CQDs) with excellent photoluminescence (PL) properties from biomass is a hot research topic. Herein, nitrogen-doped CQDs (N-CQDs) from lignin (C-source) using diethylenetriamine (DETA) as an N-source were synthesized via a facile, green, and large-scale solvothermal approach. The as-synthesized N-CQDs in ethanol (N-CQDs-ET) exhibit unique structures with abundant N-doping (~7.2%), rich functional groups (especially C O and pyrrolic-N), high degree of graphitization, and uniform particle size (~5.0 nm). The N-CQDs-ET have excellent QL properties with high quantum yield, superior fluorescence stability, and long fluorescence lifetime, all of which are much better than N-CQDs obtained from a traditional hydrothermal process. The N-CQDs-ET display excellent sensitivity for Fe3+ and Co2+ detection with a good linear correlation ranging from 0.27 to 250 μM and 0.45–500 μM, respectively. In addition, the N-CQDs-ET exhibit excellent biocompatibility and multicolored cell imaging ability, showing great potential applications in biosensors. [Display omitted] • Lignin derived N-CQDs are efficiently produced via ethanol solvothermal approach. • N-CQDs produced in ethanol have excellent QL properties due to unique structures. • N-CQDs produced in ethanol have better QL properties than those in hot water. • The N-CQDs-ET sample displays excellent sensitivity for Fe3+ and Co2+ detection. • N-CQDs-ET sample has great biocompatibility and cell multicolored imaging ability. [ABSTRACT FROM AUTHOR]

To confirm the prospects for application of pre-corrected pH hydrothermal pretreatment in biorefineries, the effects of pH on the dissolution and degradation efficiency of carbohydrates were studied. The species composition of the hydrolysate was analyzed using high efficiency anion exchange chromatography and UV spectroscopy. The result showed that the greatest balance between the residual solid and total dissolved solids was obtained at pH 4 and 170 °C. Maximum recovery rates of cellulose and lignin were as expected, whereas hemicellulose had the least recovery rate. The hemicellulose extraction rate was 42.19%, and the oligomer form accounted for 93.39% of the product. The physicochemical properties of bamboo with or without pretreatment was characterized. Compared with the traditional hydrothermal pretreatment, the new pretreatment bamboo has higher fiber crystallinity and thermal stability. In the pretreatment process, the fracture of β-aryl ether bond was inhibited and the structural dissociation of lignin was reduced. The physicochemical properties of bamboo was protected while the hemicellulose was extracted efficiently. It provides theoretical support for the efficient utilization of all components of woody biomass. [ABSTRACT FROM AUTHOR]