Photothermal Properties and Solar Water Evaporation Performance of Lignin-Based Polyurethane Foam Composites.

Solar interfacial evaporation is the most promising route for desalination because it is highly efficient, affordable and offers green energy. Polyurethane foam (PUF) is an ideal substrate material for efficient solar water evaporation because of its low thermal conductivity, affordability, and high efficiency for continuous water transport. However, PUF exhibits poor mechanical properties after water absorption and expansion, and lacks the photothermal conversion effect. In this study, biorefinery lignin with efficient photothermal properties was introduced to prepare functional lignin-based PUF (LPUF), and the relationship between the molecular structure of fractioned lignin and the solar water evaporation performance was systematically investigated. The addition of lignin effectively enhanced the mechanical properties of LPUF after water absorption and swelling, and imparted the foam with a photothermal conversion effect. The water evaporation rate of LPUF was as high as 2.58 kg m-2 h-1 and could be further improved to more than 3.0 kg m-2 h-1 after loading polyaniline (PANI) on the surface of LPUF. LPUF-PANI exerted an excellent purification effect on dye wastewater with outstanding long-term stability, providing a potential solution for ecofriendly and sustainable economic production of fresh water. This study broadens the effective utilization of LPUF bulk materials in the fields of energy and environment.

Ru-FeNi Alloy Heterojunctions on Lignin-derived Carbon as Bifunctional Electrocatalysts for Efficient Overall Water Splitting.

Rational design of efficient, stable, and inexpensive bifunctional electrocatalysts for oxygen evolution reactions (OER) and hydrogen evolution reactions (HER) is a key challenge to realize green hydrogen production via electrolytic water splitting. Herein, Ru nanoparticles and FeNi alloy heterojunction catalyst (Ru-FeNi@NLC) encapsulated via lignin-derived carbon was prepared by self-assembly precipitation and in situ pyrolysis. The designed catalyst displays excellent performance at 10 mA cm-2 with low overpotentials of 36 mV for HER and 198 mV for OER, and only needs 1.48 V for overall water splitting. Results and DFT calculations show the unique N-doped lignin-derived carbon layer and Ru-FeNi heterojunction contribute to optimized electronic structure for enhancing electron transfer, balanced free energy of reactants and intermediates in the sorption/desorption process, and significantly reduced reaction energy barrier for the HER and OER rate-determining steps, thus improved reaction kinetics. This work provides a new in situ pyrolysis doping strategy based on renewable biomass for the construction of highly active, stable and cost-effective catalysts.

Lignin-assisted electronic modulation on NiSe/FeOx heterointerface for boosting electrocatalytic oxygen evolution reaction.

The development of productive and durable non-precious metal catalysts for the sluggish oxygen evolution reaction (OER) is critical for water splitting. Herein, a novel NiSe-FeOx heterojunction encapsulated in lignin-derived carbon layer (NiSe-FeOx@LC) was synthesized via hydrothermal self-assembly and in-situ pyrolysis. NiSe-FeOx@LC exhibited excellent OER performance with an overpotential of 265 mV at 50 mA·cm-2, a Tafel slope of 83 mV·dec-1, as well as long-term stability. Both experimental and DFT calculation results indicated that the doping of FeOx into NiSe@LC successfully optimized the dual interface structure between NiSe and FeOx, thereby promoted the d-bands orbital hybridization, that facilitated electron transfer. Besides, the carbon coating effectively protected the NiSe-FeOx components from leaching and agglomerating during the reaction. This study provides insight into the significance of lignin-derived carbon-encapsulated metallic catalyst for electrocatalytic OER process.

Interpretation of the phenolation and structural changes of lignin in a novel ternary deep eutectic solvent.

Deep eutectic solvents (DES) are promising green solvents for depolymerization and reconstruction of lignin. Revealing the transformations of lignin during DES treatment is beneficial for high potential lignin applications. In this study, bagasse lignin was treated with a binary DES and three ternary DESs, respectively. The results showed that net hydrogen bonding acidity(α-ß) value of DES was positively correlated to the increment of phenolic hydroxyl of lignin, and the ternary DES of choline chloride-formic acid-oxalic acid (ChCl-FA-OA) exhibited the best phenolation performances. The phenolic hydroxyl content of ChCl-FA-OA treated lignin was increased by 50.4 %, reaching 2.41 mmol/g under optimum conditions (120 °C, 4 h, ChCl-FA-OA = 1:2:1). Moreover, it was found that the cleavage of ß-O-4' aryl ether bond and ester bond were dominant reactions during the treatment, accompanied by condensation reactions. Additionally, the obtained lignin oil contained various syringyl and guaiacyl derived phenolic compounds. Especially, the content of acetovanillone in lignin oil reached 29.94 %, much higher than in previous studies. Finally, the degradation mechanism of lignin in ChCl-FA-OA system was proposed. The present work provided insights into the relationship between lignin phenolation and DES properties. The novel ChCl-FA-OA system can achieve efficient lignin depolymerization, and convert lignin biomass into value-added chemical products.

A Co-based nitrogen-doped lignin carbon catalyst with high stability and wide operating window for rapid degradation of antibiotics.

Co-based catalysts play a crucial role in the activation of peroxymonosulfate (PMS) for degradation contaminants. However, the practical application of such catalysts is hindered by challenges like the self-aggregation of Co nanoparticles and leaching of Co2+. In this study, the Co-based catalyst Co-N/C@CL was synthesized from carboxymethylated lignin obtained by grafting abundant carboxymethyl groups into alkali lignin, in which the presence of these carboxymethyl groups enhanced its water solubility and allowed the formation of stable macromolecular complexes with Co2+. This catalyst exhibited a high specific surface area (521.8 m2·g-1) and a uniform distribution of Co nanoparticles. Consequently, the Co-N/C@CL/PMS system could completely remove 20 ppm tetracycline (TC) in 2 min at a rate of 2.404 min-1. Experimental results and DFT calculations revealed that the synergistic effect of lignin carbon and Co NPs accelerated the cleavage and electron transfer of OO bonds, thus promoting the formation of 1O2, OH and SO4-, with 1O2 emerging as the predominant contributor. Moreover, Co-N/C@CL displayed excellent cycling stability and low Co2+ leaching. This work not only provides a feasible strategy for the preparation of highly active and stable Co-based carbon materials but also offers a promising catalyst for the efficient degradation of TC.

Construction of PVA-lignosulfonate hydrogels for improved mechanical performances and all-in-one flexible supercapacitors.

All-in-one supercapacitors are one of the best candidates for realizing flexible supercapacitors because of their outstanding flexibility and stability. The pursuit of improved electrochemical performance while meeting the requirements of flexible functionalization has always been a long-term goal. To this aim, lignosulfonate (LS) can be used in the field of all-in-one supercapacitors and contribute to its unique three-dimensional structure and abundant functional groups. By doping a small amount of LS, a simple approach is developed to achieve a one-step improvement in electrochemical performance and flexible functional design in this study. PVA-lignosulfonate hydrogel (PLH) obtains a compact and regular three-dimensional porous structure, higher ionic conductivity (0.17 S/cm), bending flexibility, and compression resistance. Polyaniline (PANI) based solid-state supercapacitors PANI-PVA and PANI-PLH show specific capacitance values of 505 and 558 mF/cm2, respectively, at a current density of 0.5 mA/cm2. After 5000 charge-discharge cycles, the capacitance retention rate increases from 53 % to 73 %, and the PANI-PLH can maintain the stability of electrochemical performance under bending, folding, puncturing, and squeezing. After 1600 times folding, the capacity remains almost 100 %. This study presents a one-step optimization for the construction of functional and high-performance all-in-one supercapacitors in a simple way and a novel idea for the potential application of the high-value lignin.

Lignin-derived carbon-supported MoC-FeNi heterostructure as efficient electrocatalysts for oxygen evolution reaction.

Developing noble-metal-free electrocatalysts for efficient oxygen evolution reactions (OER) is urgently desired to obtain green hydrogen by water electrolysis. Coupling FeNi catalysts with other transition metals is an effective strategy to improve the OER performance, but the electronic structure regulation of the catalytic center is challenging. Herein, heterostructures catalyst composed of MoC and FeNi alloy embedded in N-doped biochar (denoted as MoC-FeNi@NLC) was in situ synthesized by pyrolysis of lignin-metals coordination complex. MoC-FeNi@NLC displayed an overpotential of 198 mV and a long steady running time of 200 h at 10 mA·cm-2 in alkaline media. Furthermore, MoC-FeNi@NLC has demonstrated excellent Faradaic efficiency (FE) of over 90 %. A voltage of 1.50 V was required based on the MoC-FeNi@NLC and Pt/C coupling system, which was superior to that of commercial noble metal catalysts (Pt/C || Ir/C, 1.57 V). The density functional theory demonstrated that FeNi alloy balanced the adsorption energy of OER intermediates and regulated the orbital overlap of Mo above Fermi level. While the lignin-derived carbon layer prevented the deactivation and dissolution of catalytic center. The construction strategy of transition metal alloys and carbides heterojunction by the assistance of sustainable lignin derivatives and its structure-activity relationship toward OER electrocatalytic process provides a promising and cost-efficient pathway for the design of high-performance and stable OER catalysts.

Lignosulfonate-assisted in situ synthesis of Co9S8-Ni3S2 heterojunctions encapsulated by S/N co-doped biochar for efficient water oxidation.

The development of highly active and stable earth-rich electrocatalysts remains a major challenge to release the reliance on noble metal catalysts in sustainable (electro)chemical processes. In this work, metal sulfides encapsulated with S/N co-doped carbon were synthesized with a one-step pyrolysis strategy, where S was introduced during the self-assembly process of sodium lignosulfonate. Due to the precise coordination of Ni and Co ions with lignosulfonate, an intense-interacted Co9S8-Ni3S2 heterojunction was formed inside the carbon shell, causing the redistribution of electrons. An overpotential as low as 200 mV was obtained over Co9S8-Ni3S2@SNC to reach a current density of 10 mA cm-2. Only a slight increase of 14.4 mV was observed in a 50 h chronoamperometric stability test. Density functional theory (DFT) calculations showed that Co9S8-Ni3S2 heterojunctions encapsulated with S/N co-doped carbon can optimize the electronic structure, lower the reaction energy barrier, and improve the OER reaction activity. This work provides a novel strategy for constructing highly efficient and sustainable metal sulfide heterojunction catalysts with the assistance of lignosulfonate biomass.

Zinc Vacancy Promotes Photo-Reforming Lignin Model to H2 Evolution and Value-Added Chemicals Production.

Lignin, rich in ß-O-4 bonds and aromatic structure, is a renewable and potential resource for value-added chemicals and promoting H2 evolution. However, direct photo-reforming lignin remains a huge challenge due to its recalcitrant structure. Herein, a collaborative strategy is proposed by dispersing Pt on zinc-vacancy-riched ZnIn2 S4 (Pt/VZn -ZIS) for revealing the effect of lignin structure during photo-reforming process with lignin models. And a series of theoretical calculations and experimental results show that lignin model substances with more nucleophilic group structures will have a stronger tendency to occur the photo-reforming reactions. In addition, benefiting of Pt-S electronic channel is formed by occupying Pt atom onto zinc vacancies in ZnIn2 S4 , which can effectively reduce the energy barrier of H2 evolution and accompany the selective oxidation of lignin model from Cα-OH to Cα = O under simulated sunlight. The natural lignin is used to further demonstrate this selective oxidation mechanism. The presented work demonstrates the photo-reforming lignin model mechanism and the influence of lignin-structure during the process of photo-reforming.

Simultaneous Oxidative Cleavage of Lignin and Reduction of Furfural via Efficient Electrocatalysis by P-Doped CoMoO4.

Electrochemical oxidative lignin cleavage and coupled 2-furaldehyde reduction provide a promising approach for producing high-value added products. However, developing efficient bifunctional electrocatalysts with noble-metal-like activity still remains a challenge. Here, an efficient electrochemical strategy is reported for the selective oxidative cleavage of Cα -Cß bonds in lignin into aromatic monomers by tailoring the electronic structure through P-doped CoMoO4 spinels (99% conversion, highest monomer selectivity of 56%). Additionally, the conversion and selectivity of 2-furaldehyde reduction to 2-methyl furan reach 87% and 73%, respectively. In situ Fourier transform infrared and density functional theory analysis reveal that an upward shift of the Ed upon P-doping leads to an increase in the antibonding level, which facilitates the Cα -Cß adsorption of the lignin model compounds, thereby enhancing the bifunctional electrocatalytic activity of the active site. This work explores the potential of a spinel as a bifunctional electrocatalyst for the oxidative cracking of lignin and the reductive conversion of small organic molecules to high-value added chemicals via P-anion modulation.

Successive organic solvent fractionation and homogenization of technical lignin for polyurethane foam with high mechanical performance.

This work demonstrates an organic solvent fractionation method for lignin homogenization, which can effectively reduce the lignin heterogeneity and use each lignin fraction to prepare polyurethane foams (PUFs) with excellent mechanical properties. Such fractions were fully characterized by GPC, NMR (31P, 2D-HSQC), FTIR, and TG to obtain a detailed description of the structures and properties. The properties of PUFs from each lignin fraction showed higher compatibility than that from unfractionated industrial lignin, as studied by morphology and DSC analysis. The improvement of compatibility between the fractionated lignin fractions and polyethylene glycol can effectively enhance the mechanical properties of the prepared PUFs. The hysteresis loss (43.10%-51.85%) and resilience (95.81%-98.81%) of the fractionated lignin polyurethane foams (LPUFs) were better than that from the unfractionated LPUFs (hysteresis loss 41.64%, resilience 94.67%) at the lignin content of 5%. Subsequently, the strong relationships between lignin structures and PUF properties were demonstrated in detail. The suggested approach provides greater possibilities to prepare LPUFs with tunable properties based on real industrial lignin fractions, rather than modified lignin.

Sodium Pre-Intercalated Carbon/V2 O5 Constructed by Sustainable Sodium Lignosulfonate for Stable Cathodes in Zinc-Ion Batteries: A Comprehensive Study.

The aqueous zinc-ion battery (AZIB) has been widely investigated in recent years because it has the advantages of being green, safe, and made from abundant raw materials. It is necessary to continue to study how to prepare cathode materials with excellent performance and high cycling stability for future commercialization. In this work, a strategy was proposed that uses sustainable sodium lignosulfonate as both carbon and sodium sources to obtain a sodium pre-intercalated vanadium oxide/carbon (VO/LSC) composite as the cathode of AZIB. The carbon matrix could improve the electronic conductivity of vanadium oxide, while the sodium lignosulfonate could provide sodium ions pre-intercalated into the layered vanadium oxide simultaneously. Through this strategy, vanadium-based cathode materials with high stability and excellent rate capability were obtained. The VO/LSC cathode delivered high capacities of 350 and 112.8 mAh g-1 at 0.1 and 4.0 A g-1 , respectively. Zinc sulfate and zinc trifluoromethyl sulfonate were selected as electrolytes, and the influence of electrolytes on the performance of VO/LSC was analyzed. The oxygen in the environment was used to oxidize the low-priced vanadium oxide to achieve a self-charging AZIB. This paper provides a valuable strategy for the design of vanadium-based cathode material for AZIB, which can broaden the research and application of AZIB.

Preparation of formyl cellulose and its enhancement effect on the mechanical and barrier properties of polylactic acid films.

Cellulose was modified by formic acid to prepare formyl cellulose (FC). The amount of formyl groups in FC was adjusted by controlling the reaction time, reaction temperature, and formic acid concentration. Then, FC was used to reinforce polylactic acid (PLA) films prepared by solution casting. Scanning electron microscopy (SEM) shows that long rod-like cellulose particles were broken into short rods after formylation and the introduction of FC made PLA surface rougher. The mechanical properties of PLA/FC films were improved by the inclusion of FC. Compared to pure PLA film, the PLA/FC composite film with 1 wt% FC (containing 15.79% formyl groups) showed a 48.59% increase in tensile strength and a 346% increase in Young's modulus. The addition of FC also resulted in better water barrier properties. The moisture absorption capacity and water vapor permeability were 40.56% and 51.43% lower than those of the pure-PLA film. The enhancement in properties for PLA/FC composites could be ascribed to the improved compatibility between PLA and cellulose with the introduction of hydrophobic formate groups. The PLA/FC composite films developed in this work could be highly potential for food packaging.

Rational design of 3D/2D In2O3 nanocube/ZnIn2S4 nanosheet heterojunction photocatalyst with large-area "high-speed channels" for photocatalytic oxidation of 2,4-dichlorophenol under visible light.

We have rationally designed and fabricated of "face-to-face" 3D/2D In2O3 nanocube/ZnIn2S4 nanosheet heterojunction by growing ZnIn2S4 nanosheets on the surfaces of In2O3 cubes as photocatalysts for 2,4-dichlorophenol (2,4-DCP) degradation under visible light. Herein, the unique 3D/2D In2O3 nanocube/ZnIn2S4 nanosheet hierarchical structure not only exposes far more abundant heterojunction interface active sites compared to 3D/0D In2O3 nanocube/ZnIn2S4 nanoparticle, but also produces numbers of compact high-speed nanochannels in the junctions, which significantly promotes the separation and migration of photogenerated carriers. Profiting by structural and compositional advantages, the optimized 3D/2D ZnIn2S4-In2O3 photocatalyst shows excellent photocatalytic activity and stability in the degradation of 2,4-DCP, which is 1.85, 2.60, 3.02 and 3.54-fold higher than that of 3D/0D ZnIn2S4-In2O3, ZnIn2S4 nanosheet, ZnIn2S4 nanoparticle and In2O3, respectively. Meanwhile, the main active species (·O2-, ·OH and h+) produced in the photodegradation process were determined and the intermediates and degradation mechanism were studied in detail. Besides, the application on the removal of 2,4-DCP in natural water and actual wastewaters by 3D/2D ZnIn2S4-In2O3 also have been studied. This work provides a new strategy for efficiently optimize the advantages of binary nano-architectures to effectively degrade phenolic pollutants in the environment.

Preparation and interaction mechanism of Nano disperse dye using hydroxypropyl sulfonated lignin.

Particles size of disperse dye in dye bath seriously affected its dyeing quality. Here, we prepared a nano disperse dye with average particles size of 94 nm by self-assembly using a hydroxypropyl sulfonated alkali lignin dispersant (HSAL) and azo disperse dye (C.I. disperse Blue 79). The nano disperse dye exhibited excellent dispersion and stability at high temperature (130 °C), the particle size of that was 1.97 µm. The reducing effect of nano dye (azo structure) was decreased to 5.39% and the dye uptake reached up to 94.27%. The interaction mechanism between lignin derivatives dispersant and dye particles was investigated through the adsorption behaviors by employing quartz crystal microbalance with dissipation monitoring and AFM. The higher adsorption amount of HSAL on the dye surface displayed the more viscoelastic adsorption layer than that of sodium lignosulfonate. High sulfonic group attached to the long alkyl chain in HSAL molecules can stretch out to the aqueous phase to provide a strong electrostatic repulsion to disperse dye particles and form the nano disperse dye self-assembly. The present study provided a novel preparation method of nano disperse dye, that would broaden the efficient and value-able utilization of biomass lignin in dyeing and printing field.

Synthesis and characterization of biomass lignin-based PVA super-absorbent hydrogel.

The traditional polyvinyl alcohol composite hydrogel exhibited poor swelling and mechanical properties, which limited its application. To solve these issues, we use biomass lignin as raw material, PVA as matrix template and epichlorohydrin as cross-linker to prepare the Lignin-PVA super-absorbent hydrogels with the swelling ratio of up to 456 g/g under mild condition. When the lignin concentration was increased from vacancy to 5%, the swelling ratio of the Lignin-PVA hydrogels was increased from 92 g/g to 456 g/g. The lignin-based hydrogel synthesized by the higher molecular weight PVA showed better swelling performance. Softwood lignin, hardwood lignin and corncob lignin could also be used to fabricate the Lignin-PVA super-absorbent hydrogels with the swelling ratio of higher than 500 g/g. However, the optimum amount varied from different lignin types, which was related to the molecular weight and phenolic hydroxyl content of lignin. The structural mechanism of the Lignin-PVA hydrogel was proposed to clearly certify the enhancing role of lignin. The adsorption capacity of the Lignin-PVA hydrogel with respect to rhodamine 6G, crystal violet and methylene blue dyes was up to 196, 169 and 179 mg/g, respectively. The Lignin-PVA hydrogel presents great potential applications in the fields of soil water retention and seed cultivation in agriculture, and dye pollutant removal.

Facile preparation of biomass lignin-based hydroxyethyl cellulose super-absorbent hydrogel for dye pollutant removal.

The severe preparation process, poor swelling properties and mechanical properties of traditional cellulose and polyvinyl alcohol (PVA) composite hydrogels heavily limited their practical applications. To solve these issues, we use long-chain hydroxyethyl celluloses (HECs) as framework backbones, short-chain PVAs as branched chains, lignin molecules as extended crosslinkers and epichlorohydrin molecules as crosslinkers to prepare the lignin-based hydroxyethyl cellulose-PVA (LCP) super-absorbent hydrogels in the alkaline aqueous solution under mild reaction conditions, demonstrating high swelling ratio of up to 1220 g/g. The LCP hydrogels could take up large amounts of positively charged dyes rhodamine 6G, crystal violet and methylene blue with uptakes of 153, 184 and 196 mg/g, respectively. The LCP super-absorbent hydrogels also present excellent water retention, biodegradability and excellent swelling properties, which are very promising for applications in the fields of commercial diapers, soil water retention and seed cultivation in agriculture, and dye pollutant removal.

Effect of lignin-based amphiphilic polymers on the cellulase adsorption and enzymatic hydrolysis kinetics of cellulose.

The origin, amount, hydrophilicity, charge, molecular weight and its distribution of lignin have significant influences on the enzymatic hydrolysis of lignocellulose. The enzymatic hydrolysis of lignocellulose was essentially enhanced by lignin-based polyoxyethylene ether (EHL-PEG), whereafter followed by PEG4600 and lignosulfonate (LS). The effect of LS, EHL-PEG and PEG4600 on the adsorption and enzymatic hydrolysis kinetics of cellulase on the gold surface and cellulose film was investigated by Quartz Crystal Microbalance with dissipation monitoring (QCM-D). Results showed that the interaction of LS or EHL-PEG with cellulase was electrostatic attractive and hydrophobic effect, respectively, and formed hydrophilic cellulase aggregates. LS-Cellulase peeled off the cellulose film layer by layer, while the hydrophobic phenylpropane structure of EHL-PEG-Cellulase acted as a cellulose binding domain to hydrolysis cellulose through "Hollow" effect and made cellulose become more loose and swollen. At last, a strategy to enhance the enzymatic hydrolysis of lignocellulose by lignin-based amphiphilic polymers was proposed as well.

Improved enzymatic hydrolysis of hardwood and cellulase stability by biomass kraft lignin-based polyoxyethylene ether.

Water-soluble kraft lignin-based polyoxyethylene ether (KL-PEG), synthesized from the black liquor of kraft pulping and PEG, was used to improve the enzymatic hydrolysis efficiency of dilute acid pretreated (DA-pretreated) Eucalyptus hardwood and cellulase stability. The physicochemical properties of KL-PEG polymer such as solubility, surface tension, charge and aggregation behavior in the solution were first studied. KL-PEG could enhance the enzymatic hydrolysis of Avicel and DA-pretreated Eucalyptus from 63.6% and 58.3% to 78.5% and 93.8%, respectively. The enzymatic activity of cellulase after the enzymatic hydrolysis of Avicel and DA-pretreated Eucalyptus for 72 h remained approximately 84% and 44% in the presence of KL-PEG polymer. KL-PEG could improve the stability and longevity of the cellulase, facilitate the recovery and save the amount of cellulase. The efficient utilization of the pulping black liquor lignin was of great significance to alleviate the pressure brought by the shortage of petrochemical resources, and build an energy-saving and low-carbon society.

Facile fabrication and characterization of highly stretchable lignin-based hydroxyethyl cellulose self-healing hydrogel.

In this study, hydroxyethyl cellulose (HEC) and polyvinyl alcohol (PVA) as the framework, borax as the cross-linker, and biomass lignin from pulping black liquors and biorefinery as the plasticizer were used to synthesize the lignin-based HEC-PVA (LCP) self-healing conductive hydrogel with highly stretchable and thermosensitive properties by the one-step fabrication method. Compared with the PVA hydrogel, the maximum storage modulus and the elongation rate was increased by 7 times and 20 times, respectively. Uniformly distributed lignin could increase the mobility and distance of polymer molecular chains, therefore improve the viscoelasticity and stretchability of the LCP self-healing hydrogel. The LCP hydrogel could recover to the original state in 12 s after 10000% shear strain for 4 cycles. The LCP hydrogel also presented good thermosensitivity and electrical conductivity, and were very promising for applications in the fields of 3D printing and wearable electronic devices, that broadened the efficient utilization of biorefinery lignin.