Transparent wood engineering enables the transformation of natural wood into various optical materials. However, typical top-down strategies rely on lignin removal, which significantly reduces the near-infrared (NIR) selectivity of the resulting materials, making it challenging to develop wood-based NIR optical filters. Herein, we present a lignin-enrichment approach to fabricate highly NIR-selective optical filters directly from natural wood. By enriching the lignin content from 19.81% to 35.19%, we amplify its dual functionality in ultraviolet-visible (UV-Vis) light absorption and binding ability, increasing the NIR selectivity of wood after densification. The resulting wooden filters completely block light below 600 nm while achieving an NIR transmittance exceeding 80%, enabling them to harness 77.90% of solar NIR for phototherapy. This lignin-enrichment approach not only establishes a transformative strategy for designing NIR optical filters but also promotes the efficient utilization of natural wood and solar NIR energy.

Modern electrical devices are increasingly pursuing higher efficiency, miniaturization, and durability, raising demands for advanced insulating nanomaterials. To address the high cost of aramid nanofiber (ANF)-based materials and the structural damage and cost issues associated with the purification and recovery of mica tailings, this study employs a DMSO/KOH system to treat aramid fibers, while introducing mica tailings into the process. Under sealed conditions, high-speed stirring is applied to facilitate the conversion of aramid fibers into ANFs and to reduce the particle size of the mica tailings. The resulting ANF sol containing mica tailings is then used to fabricate mica tailings/aramid nanofiber composite films via a sol-gel-film method, assisted by a multilayer hot-pressing technique. The results indicate that the mechanical properties and insulation performance of the composite films initially improve and subsequently decline with increasing mica tailing content and hot-pressing layers. The composite film containing 20 % mica tailings demonstrated optimal overall performance, with tensile strength, breakdown strength, and toughness enhanced by 42 %, 93.7 %, and 195 %, respectively, compared to the pure ANF film. These properties highlight significant potential for electrical insulation and structural material applications.

In this study, a modified synthetic method for labeling a lignin dimer (guaiacylglycerol-β-guaiacyl ether-[α-13C]) was developed. The chemical structure of the target compound was analyzed using 1H-NMR, 13C-NMR, and other analytical techniques. Then, the 13C-labeled phenolic lignin model compound was subjected to kraft pulping in the presence of xylose. Finally, the resulting reaction products were fractionated using acid precipitation and ethyl acetate extraction, and each fraction was analyzed by carbon-13 nuclear magnetic resonance (13C-NMR) and two-dimensional heteronuclear multiple quantum coherence (HMQC) spectroscopy. This aimed to investigate the occurrence of lignin–carbohydrate complexes (LCCs) during the conventional kraft pulping process. Employing ethanol as the reaction medium facilitated the bromination of 4-acetylguaiacol-[α-13C], resulting in a homogeneous reaction and significantly improving the yield of the brominated product to over 90%. Additionally, kraft pulping of the phenolic lignin model compound in the presence of xylose led to the occurrence of minor quantities of benzyl ether-type lignin–carbohydrate complex (LCC) structures, which were predominantly detected in the ethyl acetate extractive.

During the evolutionary development of plants, lignin emerged, engaging in a remarkable synergy with polysaccharides. This union enhanced the adaptability of plants to harsh environments through a complementary relationship. Lignin addresses the inherent limitations of polysaccharides, providing hydrophobicity, ultraviolet (UV) resistance, and environmental stability. Building on this natural paradigm, we explore the development of artificial lignin/polysaccharide composites (LPCs), encompassing a range of combinations such as lignin/cellulose, lignin/chitosan, lignin/starch, lignin/alginate, lignin/agarose, and lignin/carrageen composites. This review provides a comprehensive examination of lignin’s origins, understanding, properties, and the advancements and challenges faced by polysaccharides. We detail the fabrication of LPCs from lignin and natural polysaccharides, discussing their construction strategies, properties, and potential applications. Furthermore, we highlight existing challenges and future opportunities for the improved utilization of LPCs. Our aim is to catalyze the effective use of lignin and natural polysaccharides, offering fresh insights for the innovation of next-regeneration LPCs.

Lignin can be used as a natural anticancer drug because of its potential biological activity and low cytotoxicity. This research focuses on oligomeric dehydrogenation polymers (DHPs) of lignin. The lignin precursor coniferin was used to yield Zulaufverfahren dehydrogenation polymers (ZL-DHPs) and Zutropfverfahren dehydropolymers (ZT-DHPs) catalyzed by mixed enzymes. The 13C-NMR determination showed that the DHPs obtained were similar to natural lignin, and ZL-DHP had a slightly higher β-5 content than ZT-DHP. ZL-DHPs and ZT-DHPs were subjected to organic solvent extraction with different polarities to obtain eight fractions, i.e., ZL-1-ZL-4 and ZT-1-ZT-4. The antitumor activity showed ZL-2 (IC50 181.99 μg/mL) and ZT-2 (IC50 246.76 μg/mL) had significant inhibitory effects. Fractions ZL-2 and ZT-2 were purified through column chromatography using gradient-polarity binary eluent, and 12 purified compounds were obtained, i.e., L1–L6 and T1–T6. The results showed L2 (IC50 33.99 μg/mL) and T1 (IC50 42.08 μg/mL) had relatively high biological activity, respectively. Their structure was characterized using high-resolution mass spectrometry and 13C-NMR, indicating that L2 is a dimer with β-5 linkage (β-5, γ-CH3, and γ'-CH2OH), and T1 is also a dimer with β-5 linkage but different substituents (β-5, γ-CHO, and γ'-COOH).

Near-infrared (NIR) filters have broad applications in fields such as information safety and privacy protection and environmental monitoring. Traditional NIR filters primarily rely on complex optical designs and environmentally unfriendly substrates, while lignocellulose-sourced NIR filters do not achieve the desired blocking wavelength and therefore face challenges in various application conditions. In this study, we propose a thickness adjustment strategy to precisely control the blocking wavelength of the NIR optical filters. The obtained optical filters with tailored thickness exhibited selective blocking wavelength in visible region (400-650 nm) as well as a high NIR transmittance (over 90%) and ultralow haze at 1400 nm. Given their selective wavelength blocking and high NIR transmittance, these bioselectors demonstrate potential applications in NIR optical fields, such as data security and privacy protection, presenting a promising advancement in next-generation sustainable NIR optical materials fabricated from all-lignocellulose feedstocks.

With the increasing demand for high power and miniaturization of modern large-scale electrical equipment, preparing high-performance electrical insulation materials with high thermal stability and excellent mechanical properties has become an urgent problem. In this study, hydroxyapatite (HAP) nanowires and aramid nanofibers (ANF) multifunctional composites were prepared by sol-gel-membrane strategy. Aramid fibers containing an amide structure and HAP can form an ordered hydrogen bonding network and exhibit strong hydrogen bonding. The prepared HAP/ANF nanocomposite films with nanowire/nanofiber network skeleton and laminate structure have good tensile strength (69.6MPa), dielectric breakdown strength (65.7kVmm-1), and processing properties. Particularly emphasized is that the multifunctional HAP/ANF nanocomposite films are fireproof and high-temperature resistant, and the interfacial hydrogen-bonding enhancement between HAP nanowires and aramid fibers facilitates the construction of multifunctional insulating materials.

Miniaturized, integrated, and functional electronic devices generate a large amount of heat accumulation during operation, which significantly affects the reliability, durability, and safety of electronic devices. In severe cases, it may even lead to fires. Therefore, the development of insulation composite materials with thermal conductivity and flame-retardant properties is particularly important. In this study, we propose an in-situ mineralization strategy to prepare insulation composite materials with thermal conductivity and flame-retardant properties. By dissolving and preparing a gel film, Al3+ and Zn2+ retained inside the lignocellulose are in situ mineralized to form Al(OH)3 and ZnO, and introducing inorganic blocks with high insulation performance (industrial waste mica tailings and synthetic mica). The prepared film has excellent tensile strength (117.4 MPa), low dielectric loss, high dielectric strength (83.8 kV mm- 1), high insulation resistance, four times higher thermal conductivity than the unmineralized film, and excellent flame-retardant properties. Meanwhile, the environmental impact of the composite film is much lower than that of petrochemical-based plastic films and can easily degrade under natural conditions within 32 days. It is a composite material that meets the standards of the new electrical insulation field, and the in-situ mineralization strategy can also provide ideas for the preparation of highperformance lignocellulose-based materials.

This research focuses on the development of near-infrared light selective transmission film (NIR-LSTF) utilizing wheat straw biomass, extracting lignocellulose and lignin through the acetic acid method. Employing a hydrogelbased approach, lignin was encapsulated and underwent self-assembly both within and atop the hydrogel, enabling initial integration with cellulose. Hot pressing facilitated the thorough amalgamation of lignin into the cellulose matrix, enhancing the NIR-LSTF's resistance to environmental wear and creating a dense structure that minimizes light loss and reflection, thus outperforming traditional materials in optical efficiency and functionality. Moreover, the presence of lignin imparts the material with unique selective absorption characteristics, effectively blocking nearly all ultraviolet light and visible light (approximately 100 % at 610 nm and 78 % at 780 nm), while maintaining a high transmittance rate (similar to 90 %) in the near-infrared spectrum. This property underscores the films' significant potential in applications demanding near-infrared transparency. The efficacy of NIR-LSTF in the realms of infrared surveillance and privacy protection was assessed, yielding favorable experimental outcomes. This study paves a new pathway for the valorization of agricultural waste biomass within the near-infrared optical domain.

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Modern electrical devices are increasingly miniaturized and high-powered, leading to greater demands for advanced electrical insulating materials. Herein, multifunctional aramid nanofiber (ANF) insulating materials were prepared by in situ generation of hydroxyapatite (HAP) nanowires with a controllable aspect ratio. The dense network structure of ANF/HAP as well as the interlayer interactions resulted in the preparation of composite film materials with high tensile strength (102.35 MPa) and excellent electrical insulating properties (89.57 kV/mm). In particular, the fire-resistant and flame-retardant properties of the multilayer hot-pressed composite HAP/ANF paper were also greatly improved due to the properties of HAP. In addition, this study also provides a theoretical reference for the application of HAP flame retardants and provides ideas for the design of nanodielectric insulating materials.

Natural wood has been highly valued for thousands of years due to its excellent strength, low density, and ease of processing. However, its poor water stability, which leads to swelling and deformation, limits its competitiveness. In response, we designed a reconstructed wood through a process involving pretreatment, TEMPO oxidation, lignin self-assembly, lignin melting, and densification. In this material, cellulose serves as the skeleton, while lignin with a phenylpropyl structure acts as both a filler and binder. The resulting wood exhibits outstanding water stability, with no changes after 60 days of water immersion and a water absorption rate as low as 8.32 %. This stability is achieved through the densification of lignin, which is enhanced by lignin melting and pressure during self-assembly. The reconstructed wood not only offers excellent water stability but also boasts superior UV resistance and thermal stability. Additionally, it can be hot-pressed into straws within a mold, providing better water stability and tensile strength compared to paper straws. This reconstructed wood, made from natural wood and corncob, is biodegradable and environmentally friendly, offering a new approach to wood water stability strategies.

Lignin precursor labeled with 13C (coniferin-13Cα), carbohydrate precursor labeled with D (6,6-D2-glucose) were put into cambium tissue stripped from a growing poplar. The tissue was further cultured in vitro for 18d. Then, the isotopic abundance was determined. The results showed that the labeled precursors could be normally involved in the formation of new xylem. The labeled new xylem tissue was fractionated by ionic liquid DMSO/TBAH system to obtain two components: glucan-lignin complex (GL) and xylan-lignin complex (XL). The X-ray diffraction (XRD) results indicated that the crystalline form of cellulose in the GL component was transformed from type I to type II after the ionic liquid separation. Then the GL and XL were purified and modified by enzymatic and chemical methods, and their structures were elucidated by nuclear magnetic resonance (NMR) spectroscopy. The results showed that lignin subunits in the cultured tissues were mainly connected by β-5 and β-O-4 linkages, of which the β-O-4 substructure unit predominated. Lignin and carbohydrates were mainly connected by acetal bonds, ether bonds, and ester bonds. Combined with the carbohydrate composition and XRD analysis results, the GL components also confirmed the existence of acetal bonds, ester bonds and ether bonds between lignin and cellulose.

Tricin is a complex compound with chemical bonds to phenylpropane units of lignin in gramineous plants, and it is predominantly bound to lignin by β-O-4 ether bonds. Thioacidolysis cleaves the alkyl aryl ether bonds, which releases tricin from the tricin-lignin complex and maintains the natural structure of the tricin. In this study, milled wood lignin (MWL) was isolated from wheat straw by Bjӧrkman’s method, and the MWL was subjected to thioacidolysis to release tricin from the MWL. Medium-pressure preparative liquid chromatography was used for further purification. FT-IR and 1H-NMR analyses showed that the purified fraction was composed mainly of tricin-type flavonoids. The extracted tricin had strong scavenging capacity against 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radicals, with a half maximal inhibitory concentration (IC50) of 51.9 mg/L. Drug sensitivity paper testing showed that the extracted tricin inhibited the growth of Escherichia coli. The bacteriostatic circle diameters of tricin from wheat straw MWL and quercetin standard were 9.17 and 7.52 mm, respectively. A 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay showed that the tricin from wheat straw MWL had possible inhibitory effect on lung cancer A549 cells, with a maximum inhibitory performance of 44.5%.

Self-healing hydrogels have received considerable attention as a promising material for flexible electronic de-vices given their mechanical durability and structurally tunable properties. In this study, a highly stretchable self-healing hydrogel with dual cross-linking network was developed via borate ester bonds generated by polyvinyl alcohol and borax, and acylhydrazone bonds formed by aldehyde nanocellulose with adipic acid dihydrazide-modified alginate. Compared with the single network hydrogel composed of polyvinyl alcohol and borax, the introduction of dynamic acylhydrazone bonds greatly increases the flexibility of the hydrogel. The elongation rate increased from 480 % to approximately 1440 %, and the self-healing efficiency increased from 84.6 % to 92.7 % after healing for 60 min at ambient temperature without any stimulus. Moreover, the longer the self-healing time, the more evident the self-healing effect of the acylhydrazone bonds. In addition, electrical measurements confirmed a wide working strain range (ca.1000 %), durability, and reliability. Once assembled as a strain sensor, the hydrogel is able to monitor both large and subtle human motions. Besides, this hydrogel exhibited desirable biocompatibility, as demonstrated by in vitro cytotoxicity towards NIH 3T3 cells. These integrated properties make this nanocomposite hydrogel a promising candidate for future applications as green, flexible, and smart sensors.

Near-infrared (NIR) transparent optical filters show great promise in night vision and receiving windows. However, NIR optical filters are generally prepared by laborious, environmentally unfriendly processes that involve metal oxides or petroleum-based polymers. We propose a lignin capturing-fusing approach to manufacturing optical biofilters based on molecular collaboration between lignin and cellulose from waste agricultural biomass. In this process, lignin is captured via self-assembly in a cellulose network; then, the lignin is fused to fill gaps and hold the cellulose fibers tightly. The resulting optical biofilter featured a dense structure and smooth surface with NIR transmittance of -90%, ultralow haze of close to 0%, strong ultraviolet-visible light blocking (-100% at 400 nm and 57.58% to 98.59% at 550 nm). Further, the optical biofilter has comprehensive stability, including water stability, solvent stability, thermal stability, and environmental stability. Because of its unique properties, the optical biofilter demonstrates potential applications in the NIR region, such as an NIR-transmitting window, NIR night vision, and privacy protection. These applications represent a promising route to produce NIR transparent optical filters starting from lignocellulose biomass waste.

In this paper, guaiacyl dehydrogenated lignin polymer (G-DHP) was synthesized using coniferin as a substrate in the presence of β-glucosidase and laccase. Carbon-13 nuclear magnetic resonance (13C-NMR) determination revealed that the structure of G-DHP was relatively similar to that of ginkgo milled wood lignin (MWL), with both containing β-O-4, β-5, β-1, β-β, and 5-5 substructures. G-DHP fractions with different molecular weights were obtained by classification with different polar solvents. The bioactivity assay indicated that the ether-soluble fraction (DC2) showed the strongest inhibition of A549 lung cancer cells, with an IC50 of 181.46 ± 28.01 μg/mL. The DC2 fraction was further purified using medium-pressure liquid chromatography. Anti-cancer analysis revealed that the D4 and D5 compounds from DC2 had better anti-tumor activity, with IC50 values of 61.54 ± 17.10 μg/mL and 28.61 ± 8.52 μg/mL, respectively. Heating electrospray ionization tandem mass spectrometry (HESI-MS) results showed that both the D4 and D5 were β-5-linked dimers of coniferyl aldehyde, and the 13C-NMR and 1H-NMR analyses confirmed the structure of the D5. Together, these results indicate that the presence of an aldehyde group on the side chain of the phenylpropane unit of G-DHP enhances its anticancer activity.

Large amounts of lignin are produced as a by-product of paper pulping, resulting in a tremendous waste of natural resources with potential uses across various areas. To achieve the value-added utilization of agricultural waste and lignin, we developed a method for the fabrication of a lignin structure-designed hydrophobic film (LSHF) directly through solvent/anti-solvent self-assembly (acetic acid aqueous solution/n-hexane) and auto -adhesion of acetic acid lignin (AL) on the surface of a lignocellulose film (LCF). As the morphology structure revealed, the LSHF had a rough surface composed of lignin colloidal spheres, which significantly improved the water contact angle (WCA) from-80 degrees to-130 degrees. Furthermore, benefiting from the auto-adhesion of lignin, the WCA was more stable in 240 s, demonstrating that the LSHF had a lower WCA decrease (15.53 % - 25.55 % decrease) than the LCF (41.97 % - 61.11 % decrease) and the sample without auto-adhesion (100 % decrease). Simultaneously, auto-adhesion endowed the LSHF with a-50 % increase in tensile strength. This work provides a novel strategy for the fabrication of hydrophobic cellulose/lignin composite films via lignin self-assembly and auto-adhesion.

As a consequence of increasingly serious environmental problems, many researchers are highlighting biomass materials. Cellulose, the most abundant bioresource, is becoming a key consideration for alleviating environmental pollution. Characterization of cellulosic materials is fundamental to exploring their structures and elemental contents. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) are frequently employed to study the structure of cellulose. Thus, it is urgent to combine traditional means with new ones. This study focused on the characterization of the all-cellulose composites (ACCs) model prepared via partially dissolving filter paper using 40% benzyltrimethylammonium hydroxide (BzMe3NOH) aqueous solution. Characterized by SEM, XRD, Fourier transformation infrared spectroscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy, the unique transformation from cellulose I to cellulose II of the ACCs model was explored. These characterization methods exhibited respective features, which could be universal ways to investigate ACCs.