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As a new type of green photothermal material, lignin exhibits an excellent photothermal effect due to its abundant aromatic rings and π–π conjugated structure. To develop value-added applications of lignin in the photothermal field, it is important to explore strategies for regulating the photothermal conversion of lignin. In this work, the photothermal effect of lignin was improved significantly through modification with an electron-withdrawing group. The introduction of acetyl resulted in the formation of an electron donor–acceptor (D–A) structure in lignin and enhanced the light absorption ability. The intermolecular interaction among lignin molecules also decreased after modification with acetyl groups, leading to enhanced non-radiative decay induced by molecular motion. Under 808 nm laser irradiation at 0.51 W cm−2, the photothermal conversion efficiency of acetylated lignin (ACAL) reached as high as 73.2%, which was 37% higher than that of unmodified lignin. This study provides a new strategy to enhance the photothermal effect of lignin and deepens the understanding of the lignin photothermal mechanism. [ABSTRACT FROM AUTHOR]

Poly(butylene adipate‐co‐terephthalate) (PBAT) is a type of synthetic biodegradable thermoplastic copolyester with comparable mechanical properties to polyethylene, but the application of PBAT is limited by factors such as high cost, short shelf life, poor weather and water resistance. In order to develop PBAT composites with high performance and low cost, lignin‐modified PBAT biocomposites with enhanced tensile strength were prepared via in‐situ construction of interfacial dynamic bonds. Zinc stearate and epoxy soybean oil were introduced as the interfacial modifiers to construct dynamic bonds between lignin and PBAT, so as to improve the interfacial compatibility. The results demonstrated that the lignin/PBAT biocomposite with interface modifiers reached the maximum tensile strength of 36.7 MPa and an elongation at break of 725.3% at the lignin content of 5 wt%, with the tensile strength achieved 5% improvement on the basis of pure PBAT (34.9 MPa and 717.6%). When the lignin content was increased to 10 wt%, the lignin/PBAT biocomposite with interfacial modifiers still maintained the tensile strength of 35.4 MPa and the elongation at break of 627.8%, which was 82% and 31% higher than that of the directly compounded sample without interfacial modifiers, respectively. Even when the content of lignin loading increased to 20 and 30 wt%, the mechanical properties of the composites were still significantly improved by adding modifiers. The hydrophobicity of the composite was also improved after in‐situ interfacial modification. The strategy demonstrated in this work provides an effective reference for the development of lignin/PBAT composites with high performance but low cost. [ABSTRACT FROM AUTHOR]

Remote controllable photothermal elastomers can realize precise non-contact control through the photothermal conversion effect, highlighting a new routine for light energy utilization and a promising direction for smart materials. Developing biomass-based photothermal materials is an important strategy to promote the realization of carbon neutrality and improve the environmental friendliness of photothermal elastomers. In this work, green biomass lignin was demonstrated as an efficient photothermal agent for preparing smart elastomer composites with versatile functionalities, owing to the fact that the conjugated structures in lignin could effectively promote electron transitions from low-energy orbitals to high-energy states and the visible and near-infrared (NIR) light energy absorbed by lignin was mainly released in the form of non-radiative transition. A high photothermal conversion efficiency of 53.7% was obtained for low molecular weight alkaline lignin with the photothermal temperature exceeding 280 °C under NIR irradiation (808 nm, 1.25 W cm−2). Under the stimulation of NIR light, the alkaline lignin/polyethylene elastomer (POE) composite exhibited a good light-triggered shape memory effect, excellent light-controlled self-repairing properties with the self-repairing efficiency as high as 98.2% (808 nm, 1.25 W cm−2, 20 min), and strong photothermal bactericidal activity. Meanwhile, a series of functional applications were demonstrated based on the excellent photothermal effect of lignin, such as photothermal engines, photothermal generators and photothermal switches, which endowed lignin-based elastomer composites with considerable application prospects in smart materials for precise remote driving of robots, machines, sensors, sterilization and self-repairing equipment, etc., promoting the sustainable development and high-value utilization of biomass lignin. [ABSTRACT FROM AUTHOR]

Typically, pristine lignin is considered to have limited application in the flame retardance area, and the phosphorylation of lignin or its combination with other effective flame retardants is required to help polyurethane achieve flame retardance. Herein, three types of lignin, including sodium lignosulfonate (LS), alkaline lignin (AL) and enzymatic hydrolysis lignin (EHL), were solely applied to significantly enhance the flame retardance and thermostability of PU foams. The PU foam coated with AL or LS could show evidently enhanced flame retardance by growing dense and swelling char, radical capture and inert gas dilution to protect the PU foam from fire and heat, and the limited oxygen index could reach as high as 28.4%. The thermostability of the coated PU foam was significantly improved by retaining 44% of its weight at 900 °C. The flame retardance mechanism of lignin/PU foam was attributed to the fact that lignin could change the thermal degradation and burning behavior of PU foams in the condensed phase (char forming) and the gas phase (inert gas dilution), and by radical quenching (phenolic groups) and S–N synergism. Our research has proved that lignin alone could help PU foam and cotton fabric achieve complete flame retardance, without any phosphorylated modification or the combination with other flame retardant agents. [ABSTRACT FROM AUTHOR]

In this work, the coordination-based energy sacrificial bonds have been constructed in the interphase between lignin and polyolefin elastomer to prepare high performance lignin-based thermoplastic elastomers (TPEs). The strength and toughness of lignin-based TPEs can be adjusted by choosing different nitrogen heterocyclic compounds as reactive assistants and Fe3+ or Zn2+ as metal coordination centers. It was demonstrated that 3-Amino-1,2,4-triazole with three nitrogen atoms in the heterocyclic ring and one nitrogen branch chain could form the most efficient coordination bond system and generate the best mechanical performance. The system with ferric iron as coordination center exhibited better enhancement effect than divalent zinc. By adjusting the nitrogen-containing reactive additives or metal salts as coordination centers, the mechanical performance of the lignin-based TPE can be regulated, which provides a method for making green bio-composites with good strength and toughness, and also promotes the high value utilization of lignin in polymer materials. [ABSTRACT FROM AUTHOR]

Reusable, self‐healable, removable, and strong bio‐based polyurea adhesives were successfully synthesized via partially substituting polyetheramine with polyetheramine‐grafted lignin and introducing a chain extender containing dynamic disulfide bonds. The polyetheramine‐grafted lignin endowed the polyurea adhesives with significantly enhanced adhesion strength on either metal or wood substrates by introducing intensive hydrogen bonding interactions; the dynamic disulfide bonds played a key role in the excellent self‐healing and reusable performance. The thermostability of polyurea adhesives was also improved by introducing lignin. This work provides a novel approach for the high‐value utilization of low‐cost lignin in recyclable adhesives with excellent comprehensive performance. [ABSTRACT FROM AUTHOR]

High efficiency lignin-grafted cationic polyacrylamide (L-CPA) flocculant was synthesized via "grafting to" method using acrylamide (AM), methylacryloyloxyethyltrimethyl ammonium chloride (DMC) and enzymatic hydrolysis lignin (EHL) as raw materials. The linear pre-polymer of cationic polyacrylamide (CPA) terminated with chlorine was first synthesized and then grafted onto EHL via reactions of chlorine with phenolic hydroxyl groups in lignin molecules. The synthesized L-CPA could self-assemble into octopus-like nanospheres with CPA segments dissolved in water and hydrophobic lignin skeletons concentrated in the core, which endowed the L-CPA with excellent flocculation efficiency for kaolin suspension under faintly acid, neutral or alkalescent conditions (pH = 5–9). Only a small dosage between 4.0–4.5 mg/L of L-CPA was needed for flocculation of the kaolin suspension. The charge neutralization and bridging effect was proposed for the flocculation mechanism of the lignin-grafted cationic polyacrylamide. The octopus-like L-CPA was cheap, environmentally friendly and technically feasible, showing a great prospect in wastewater treatment. Unlabelled Image • A novel flocculant of lignin-grafted cationic polyacrylamide was synthesized via "grafting to" strategy. • The lignin-grafted cationic polyacrylamide flocculant exhibited excellent flocculation efficiency. [ABSTRACT FROM AUTHOR]

In this work, a novel lignin-based carbon/ZnO (LC/ZnO) hybrid composite with excellent photocatalytic performance was prepared through a convenient and environment friendly method using alkali lignin (AL) as carbon source. The morphological, microstructure and optical properties of the as-prepared LC/ZnO hybrid composite was characterized with scanning electron microscope (SEM), X-ray diffraction (XRD), Raman and UV–vis. The resulting LC/ZnO hybrid is composed of highly dispersed ZnO nanoparticles embedded on a lignin-based carbon nanosheet, showing excellent photogenerated electrons and holes separation and migration efficiency. The photocatalytic activity of LC/ZnO was much higher than the pure ZnO. The LC/ZnO hybrid composite showed different photocatalytic mechanism for degradation of negative methyl orange (MO) and positive Rhodamine B (RhB). It showed that h + was the main photocatalytic active group during the degradation of MO, ·O 2 − and ·OH were the photocatalytic active groups during degradation of RhB. This reported photocatalyst with selective degradation of positive and negative organic dyes may have a great application prospect for photoelectric conversion and catalytic materials. Results of this work were of practical importance for high-valued utilization of lignin for carbon materials. [ABSTRACT FROM AUTHOR]

Using cheap and green lignin as a partial substitute for petroleum-based polyols is highly attractive for sustainable development of polyurethane elastomers (LPUes). However, the traditional synthesis process of LPUes inevitably uses toxic solvents that are difficult to remove or carcinogenic. Here, we reported a solvent-free synthesis method to prepare lignin-containing polyurethane elastomers (SF-LPUes) with high strength, high toughness and high elasticity. Most of the hydroxyl groups of lignin reacted with isocyanates to form a strong chemical cross-linking network, while the unreacted ones formed a dynamic hydrogen bond network with polyurethane matrix, contributing to the in-situ formation of lignin nanoparticles to build a nano-micro phase separation structure. Consequently, a dual-crosslinking network structure was formed and endowed SF-LPUes with excellent mechanical properties. Especially, the SF-LPUes prepared from low molecular alkali lignin possessed a tensile strength as high as 38.2 MPa, a maximum elongation at break of 1108 %, and an elastic recovery ratio of up to 98.7 %. Moreover, SF-LPUes showed impressing reprocessing performance and aging resistance. This work provides an industrial application prospect for the synthesis of lignin-containing polyurethane elastomers via a solvent-free synthesis process. A lignin-containing polyurethane elastomer with excellent mechanical properties, anti-aging properties and reprocessing properties is synthesized by a solvent-free method, thereby avoiding the use of carcinogenic, non-volatile and toxic solvents. The solvent-free synthesis method promoted the green synthesis of lignin-containing polyurethane elastomers and increased the feasibility of industrial production. [Display omitted] [ABSTRACT FROM AUTHOR]

Synopsis: This study presents a thiocyanogen-modulated alkali activation strategy for preparing N, S co-doped lignin hierarchical porous carbon (NSLHPC). Thiocyanate acts as a surface modulation mediator to introduce nitrogen and sulfur heteroatoms via oxygen replacement reaction. NSLHPC exhibits excellent electrochemical performance and long cycling lifespan in both symmetric supercapacitors and zinc-ion hybrid capacitors. [Display omitted] • Thiocyanogen-modulated alkali activation strategy for the preparation of NSLHPC. • Oxygen replacement reaction between KSCN and lignin carbon for N, S co-doping. • NSLHPC exhibits an impressive SSA of 2705.3 m2/g and a pore volume of 3.27 cm3/g. • NSLHPC presents remarkable electrochemical performance in aqueous supercapacitors. • DFT calculations reveal that N, S co-doping reduces the adsorption energy barrier of Zn2+. Constructing heteroatom-doped porous carbons with distinct charge storage properties is significant for high-energy–density supercapacitors, yet it remains a formidable challenge. Herein, we employed a thiocyanogen-modulated alkali activation strategy to synthesize N and S co-doped lignin hierarchical porous carbon (NSLHPC). In this process, thiocyanogen serves as a surface modulation mediator to substitute oxygen with nitrogen and sulfur species, while the combination of KOH activation and MgO template generates numerous nanopores within the carbon structure. The three-dimensional interconnected nanosheet architecture facilitates rapid ion transfer and enhances accessibility to active sites. Density functional theory (DFT) calculations demonstrate that introducing N and S heteroatoms through oxygen substitution reduces the adsorption energy barrier of Zn2+. Consequently, the optimized NSLHPC exhibits a remarkable specific capacitance of 438F/g at 0.5 A/g in 6 M KOH, delivering an energy density of 10.4 Wh/kg in the symmetric supercapacitor and an impressive energy density of 104.9 Wh/kg in the zinc-ion hybrid capacitor. The NSLHPC cathode also shows an excellent lifespan with capacitance retention of 99.0 % and Columbic efficiency of 100 % over 10,000 cycles. This study presents innovative strategies for engineering high-performance porous carbon electrode materials by emphasizing pore structure modulation and N, S co-doping as crucial approaches. [ABSTRACT FROM AUTHOR]

Lignin‐containing polyurea coating with good ultraviolet (UV) resistance is prepared by partially substituting polyetheramine with enzymatic hydrolysis lignin. Lignin is first grafted by polyetheramine chains via Mannich reaction, which improves its interfacial compatibility with polyurea matrix. The influences of the modified lignin on the chemical and corrosion resistance, UV‐aging property, and thermal stability of the polyurea coatings are studied. It is demonstrated that lignin‐containing polyurea coatings exhibit excellent UV‐aging properties. Aminating lignin with polyetheramine improves its dispersion in the polymer matrix. This work offers a novel method for the high‐value utilization of biomass lignin in anti‐UV polyurea coatings. [ABSTRACT FROM AUTHOR]

It is still a great challenge to prepare lignin/polyolefin composites with good strength and toughness. Inspired by the energy sacrificial mechanism from biomaterials, dynamic hydrogen bonds (H‐bonds) are incorporated into the lignin/ethylene‐propylene‐diene monomer (EPDM) composite system to improve the interfacial interactions between lignin and EPDM. Such H‐bonding interactions are demonstrated to be able to simultaneously improve the modulus, strength, and toughness of lignin/EPDM composites without sacrificing the extensibility. This work provides a facile method for the high‐valued utilization of lignin in the preparation of high‐performance elastomer composites using bio‐renewable resources as reinforcing agent. Inspired by the energy sacrificial mechanism from mussels, dynamic hydrogen bonds are incorporated into the lignin/ethylene‐propylene‐diene monomer (EPDM) composite system to improve the interfacial interactions between lignin and EPDM. Such H‐bonding interactions can simultaneously improve the modulus, strength, and toughness of lignin/EPDM composites without sacrificing the extensibility. [ABSTRACT FROM AUTHOR]

The pursuit of high volume and high value-added applications for lignin has been a long-term challenge. In this work, inspired by the energy sacrificial mechanism from biological materials, we developed high-performance lignin/carbon black (CB)/nitrile rubber (NBR) elastomers by constructing a dual-crosslinking network consisting of sulfur covalent bonds and dynamic coordination sacrificial bonds. Lignin was not only used for the substitution of half mass of CB in the NBR elastomer but also served as natural ligands for the Zn-based coordination bonds, providing a significant synergistic coordination enhancement effect. The mechanical performance of the elastomers can be easily manipulated by adjusting the proportion of non-permanent coordination bonds and permanent covalent bonds. Lignin/CB/NBR elastomers with a higher strength and modulus than CB-filled elastomers were obtained while maintaining excellent elasticity. The thermal stability and the high-temperature oil resistance of NBR elastomers were also improved by incorporation of lignin and metal coordination bonds. Overall, this work inspires a new solution for the design of high-performance lignin/rubber elastomers with a high lignin loading content. [ABSTRACT FROM AUTHOR]

Abstract The high-value utilization of green renewable nature lignin is an effective way to improve the economic feasibility of the lignocellulosic refine industry. Especially, the porous lignin-derived carbon (PLC) with high surface area prepared by activation is promising for application in energy storage field. However, the low graphitization degree, high micropore volume and poor structural stability of PLC have been the major obstacle for further application as the energy storage materials such as lithium ion batteries. Here, a highly dispersed lignin and carbon nanotube composites (Lignin/CNTs) were firstly prepared by hydrophobic self-assembly process based on π-π interaction, and then carbonized to obtain PLC/CNTs materials with layered structure supported by carbon nanotubes. The intervention of carbon nanotubes can improve the conductivity and structural stability of PLC, especially the microstructure, which provides a transmission channel and active site for the storage of lithium ion. Compared with PLC (900 °C, K 2 CO 3 activation), the resulting of PLC/CNTs possess lesser microporous, a large number of mesoporous channels and higher graphitization. Therefore, PLC/CNTs exhibited excellent lithium storage capacities, such as the initial coulombic efficiency increased by ca.25% and the reversible capacity increased by 24% than that of PLC. This process provides a simple method for the dispersion of CNTs, and provides basic data for the high-value of industrial lignin. Graphical abstract Image 1 Highlights • Lignin/CNTs composites were prepared by the hydrophobic self-dispersing process. • Based on the π-π interaction between aromatic rings of lignin and CNTs. • The microporous volume of the composites is greatly reduced Compared with PLC. • Lignin can be used as a dispersant for CNTs. • Compared with PLC, composite materials have higher lithium storage capacity. [ABSTRACT FROM AUTHOR]

Synopsis: N, S co-doped hierarchical porous lignin-derived carbon (NS-HPLC-K) with high specific surface area and N dopant had been synthesized via self-assembly assisted template-coupled activation, which achieved boosting capacitive performances. [Display omitted] • Self-assembly assisted template-coupled activation strategy was proposed to modulate the pore structure and surface dopants of lignin-derived porous carbon. • The N, S co-doped hierarchical porous lignin-derived carbon had a specific surface area of 2538.3 ± 9.5 m2/g with a rational N content of 3.19 at.%. • The N, S co-doped hierarchical porous lignin-derived carbon showed a boosting gravimetric capacitance of 393F/g. • The boosting capacitive performance originated from both electrical double-layer adsorption and inner pseudocapacitive redox. Heteroatom-doped porous carbon materials show promise for use as supercapacitor electrodes, but the tradeoff between surface area and the heteroatom dopant levels limits the supercapacitive performance. Here, we modulated the pore structure and surface dopants of N, S co-doped hierarchical porous lignin-derived carbon (NS-HPLC-K) via self-assembly assisted template-coupled activation. The ingenious assembly of lignin micelles and sulfomethylated melamine into a magnesium carbonate basic template greatly promoted the KOH activation process, which endowed the NS-HPLC-K with uniform distributions of activated N/S dopants and highly accessible nanosized pores. The optimized NS-HPLC-K exhibited a three-dimensional hierarchically porous architecture composed of wrinkled nanosheets and a high specific surface area of 2538.3 ± 9.5 m2/g with a rational N content of 3.19 ± 0.01 at.%, which boosted the electrical double-layer capacitance and pseudocapacitance. Consequently, the NS-HPLC-K supercapacitor electrode delivered a superior gravimetric capacitance of 393 F/g at 0.5 A/g. Furthermore, the assembled coin-type supercapacitor showed good energy-power characteristics and cycling stability. This work provides a novel idea for designing eco-friendly porous carbons for use in advanced supercapacitors. [ABSTRACT FROM AUTHOR]

The efficient development and utilization of green biomass-based macromolecule engineering materials are essential for the sustainable development of human civilization. In this study, lignin-based ethylene-propylene-diene-monomer (EPDM) composites with excellent mechanical performance were fabricated using a simple method. The effects of water-insoluble enzymatically hydrolyzed lignin (EL) and alkali lignin (KL) on the mechanical performance of the composites were investigated separately. The results showed that the tensile strength of EPDM reinforced with KL and EL increased to 24.5 MPa and 22.1 MPa, respectively, surpassing that of the carbon black (CB)-reinforced EPDM. After 72 h of thermo-oxidative aging, the retention rates of the tensile strength and elongation at break in the lignin-reinforced EPDM were much better than those formed with pure CB, indicating that lignin significantly improved the thermo-oxidative aging resistance of the composites. In summary, the Zn2+ coordination bonds formed between the interface of EPDM and lignin in lignin/CB/EPDM ternary composites effectively improved the mechanical performance and aging resistance of the composites. This study has significant implications for enhancing the utilization of lignin and green functional polymer materials. [Display omitted] • ZDMA cross-linked with the double bonds on EPDM. • ZDMA was utilized to construct Zn2+ coordination bonds between lignin and EPDM. • Zn2+ coordination bonds enhanced the mechanical properties of Lignin/CB/EPDM. • Lignin improved thermos-oxidative aging resistance of composites. [ABSTRACT FROM AUTHOR]

The characteristics of multi-hydroxyl structure and strong hydrogen bonding in polyvinyl alcohol (PVA) make its melting point close to its decomposition temperature, causing melt-processing difficulty. In this work, following the plasticization of small-molecule primary plasticizer acetamide, lignin was demonstrated as a green secondary plasticizer in realizing the melt processing and simultaneous reinforcement of PVA. During the plasticization process, lignin was able to combine with the hydroxyl groups of PVA, so as to destroy the hydrogen bonds and regularity of the PVA chains. The synergistic plasticization effect of lignin dramatically reduced the melting point of PVA from 185 °C to 151 °C. The thermal processing window of PVA composites was expanded from 50 °C to roughly 80 °C after introducing lignin. In contrast to acetamide, the addition of lignin significantly increased the tensile strength and Young's modulus of the composites to 71 MPa and 1.34 GPa, respectively. Meanwhile, lignin helped to hinder the migration of acetamide via hydrogen bonds. With the addition of lignin, the composites also displayed enhanced hydrophobicity and excellent UV shielding performance. The strategy of synergistic plasticization of lignin provides a feasible basis for the practical application of lignin in melt-processable PVA materials with good comprehensive properties. • Lignin was introduced as a green secondary plasticizer to realize the melt processing and reinforcement of PVA. • Lignin could destroy the hydrogen bonds of PVA chains and dramatically reduce the melting point of PVA. • Lignin served as physical cross-linking points to increase the tensile strength and Young's modulus of the PVA composites. • The composites also displayed low plasticizer migration, enhanced hydrophobicity and excellent UV shielding performance. [ABSTRACT FROM AUTHOR]

Nano silica (SiO 2) is usually used as a common reinforcing agent in polymer materials, in which the interfacial interaction greatly affects the mechanical properties of the composites. The reinforcement effect of silica on non-polar polymer is restricted due to their poor compatibility. In this work, amphipathic lignin modified by quaternization and alkylation was used as a modifier for silica to prepare hydrophobic lignin/SiO 2 nanoparticles by in-situ one-pot co-precipitation method. In alkaline solution, hydrophobic lignin and SiO 2 (from Na 2 SiO 3) were self-assembled to form nanospheres through electrostatic and hydrophobic interactions. The results showed that the lignin/SiO 2 nanoparticles were highly hydrophobic nanospheres with macropores in the surface. When the lignin/SiO 2 nanoparticles (10 wt%) were added to reinforce high-density polyethylene (HDPE), the mechanical properties of HDPE were improved with the strength of 24.5 MPa and the elongation of 1096%, which were increased by 10.4% and 14.3% compared with the control HDPE, because of the good compatibility and large bonding area. This work puts forward a new solution for the application of lignin in reinforcement of non-polar polymers. • Lignin was modified by quaternization and alkylation to obtain amphiphilicity. • Hydrophobic lignin/SiO 2 nanocomposites were prepared by in-situ one-pot co-precipitation method. • Lignin and SiO 2 were self-assembled to form nanospheres through electrostatic and hydrophobic interactions. • HDPE was reinforced by lignin/SiO 2 nanocomposites because of the good compatibility and large bonding area. [ABSTRACT FROM AUTHOR]

Flocculation is a common process for wastewater treatment. However, the most commonly used organic synthetic flocculants such as polyacrylamide are petroleum-based. In this work, biomass lignin was grafted with cationic starch to synthesize low-cost, green and fully biomass-based multifunctional flocculants. The cationic polyacrylamide was replaced by cheap industrial cationic starch. Hyperbranched multifunctional lignin-grafted cationic starch flocculant (CS-L) was successfully prepared via ring-opening reaction with epichlorohydrin. The mass content of lignin in the grafted product was between 16.6 % and 70.1 %. With the dosage of CS-L between 4.0 and 7.5 mg/l, the turbidity removal rate for 500 mg/l kaolin suspension reached more than 97 %. When the dosage of CS-L was 24 mg/l, the removal rate of 50 mg/l Cu2+ reached 85.7 %. Importantly, when the mixed solution of kaolin particles and Cu2+ was treated, the synchronous removal rates of kaolin and Cu2+ reached 90 % and 72 % respectively in the range of 8.0–12.0 mg/l flocculant addition. The synthesized lignin-grafted cationic starch flocculant showed an excellent multifunctional flocculation function. [ABSTRACT FROM AUTHOR]

Abstract As an abundant natural aromatic polymer with high carbon content, lignin can be regarded as an abundant carbon matrix precursor to develop cost-effective and environmental friendly porous carbon for energy storage materials. However, the porous lignin-derived carbon remains a great challenge as an anode for Li-ion batteries due to its low degree of graphitization. In this paper, a low-cost, productive and scalable industrial method has been adopted to fabricate highly graphitized lignin-based porous carbon (PLC-EHL-K 2 CO 3) with K 2 CO 3 activation using enzymatic hydrolysis lignin (EHL) as a raw material. PLC-EHL-K 2 CO 3 was composed of multilevel lamellar structure possessing high specific surface area and macro- and mesoporous. Notably, the graphitization of PLC-EHL-K 2 CO 3 was significantly improved compared with the common KOH activation. Meanwhile, the structure of lignin is an important factor affecting the structure of PLC, such as the molecular weight and oxygen functional groups. The high specific surface area, large pore volume and unique multilevel lamellar morphology bestow PLC an excellent lithium storage performance, and PLC-EHL-K 2 CO 3 electrode displays a desirable reversible capacity of 520 mAh·g−1 at a current density of 200 mA g−1 over 200 cycles and increases 47.3% than PLC-EHL-KOH, and even at 1 A g−1 a specific capacity of 260 mAh·g−1 can be retained after 1000 cycles. This higher graphitization porous carbon material from low-cost renewable lignin is a good candidate for lithium storage equipment. Highlights • K 2 CO 3 is more suitable for the activation of enzymatic hydrolysis lignin. • K 2 CO 3 can significantly improve the pore structure and graphitization of PLC. • The structure of lignin is an important factor affecting the structure of PLC. • At 200 mA g−1, the capacity can maintain 520 mAh·g−1 after 200 cycles. [ABSTRACT FROM AUTHOR]

The dissolution problem is the main obstacle for the value-added modification and depolymerization of industrial lignin. Here, a green urea aqueous solution for complete dissolution of various lignin is presented and the dissolution mechanism is analyzed by AFM, DLS and NMR. The results show that the molecular interaction of lignin decreases from 32.3 mN/m in pure water to 11.3 mN/m in urea aqueous solution. The immobility of 1 H NMR spectra and the shift of 17 O NMR spectra of urea in different lignin/urea solutions indicate that the oxygen of carbonyl in urea and the hydrogen of hydroxyl in lignin form new hydrogen bonds and break the original hydrogen bonds among lignin molecules. The shift of 1 H NMR spectra of lignin and the decrease of interactions in model compound polystyrene indicate that urea also breaks the π-π interactions between aromatic rings of lignin. Lignin dissolved in urea aqueous has good antioxidant activity and it can scavenge at least 63% free radicals in 16 min. [ABSTRACT FROM AUTHOR]

• Size controllable microcapsules loaded with active IPDI were fabricated. • Natural lignin was applied as emulsifier, reactive component and UV-blocker. • The lignin capsules were reacted with HDI and amine to form new polyurea. • New polyurea exhibit self-healing, anti-corrosion and UV-blocking performance. Aromatic skeleton and polyhydroxyl structure endow biomass lignin with excellent dispersibility, reactivity, and UV-blocking property. Herein, spherical microcapsules loaded with isophorone diisocyanate (IPDI) as core materials were prepared via interfacial polymerization in an oil-in-water emulsion, using sodium lignosulfonate (NaLS) as an emulsifier. Small amount of polydiphenylmethane diisocyanate (PMDI) was added to reinforce the shells of the capsules. The results show that the capsules were 43.4–118.3 μm with a shell thickness of 1.9–2.5 μm. The core fraction was approximately 72.6 wt% and the functional groups of IPDI, such as cyanates, were well preserved. The NaLS-based microcapsules were subsequently mixed and reacted with hexamethylene diisocyanate (HDI) and amine component successively to form new polyurea. When the new polyurea was coated on a steel substrate, it exhibited excellent self-healing property after being scratched. The healed polyurea presents nearly the same anticorrosion ability as the unscratched coating in a solution with high salt concentration. Moreover, the addition of NaLS-based capsules could effectively slow down the aging process of polyurea coatings. The color change of the self-healing polyurea leveled off after 200 h of UV irradiation, while retaining 40% of the breaking strength and 50% of elongation at break. Comparatively, the color of pure polyurea deepened continuously and the mechanical property disappeared completely. [ABSTRACT FROM AUTHOR]