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This paper summarizes our recent developments in the utilization of H-type zeolites to replace AlCl3 in exo-tetrahydrodicyclopentadiene production. H-type Y zeolites with large pore size (0.74 nm) had sufficient activities for isomerization of endo-tetrahydrodicyclopentadiene (endo-THDCPD) to form exo-tetrahydrodicyclopentadiene (exo-THDCPD). As for acidity strength, the moderate strength of zeolite acidity was favorable. The incorporation of fluorine generated more moderate acids, which improved the catalytic performance of zeolites to exo yield = 92.58%, exo selectivity = 96.47%, and suppressed the adamantane (ADM) yield = 2.32%. When NH4F/SSY = 6.57%, calcined at 500 °C, this showed an equivalent performance as AlCl3. [ABSTRACT FROM AUTHOR]

The one-pot synthesis of 1,4-naphthoquinones by the Diels–Alder reaction of dienes with para-quinones generated in situ with laccase (EC 1.10.3.2, p-diphenol:dioxygen oxidoreductase) in an aqueous medium was developed in this study. The para-quinones were generated in situ by the laccase oxidation of the corresponding 1,4-hydroquinones and subsequently underwent the Diels–Alder reaction with dienes, and further oxidation to finally generate 1,4-naphthoquinones, in good yields. This reaction methodology provides unique green chemistry synthesis for isolation of the naphthoquinones, and without relying on organic solvents or hazardous heavy metal reagents. In this paper, the effects of laccase dose, temperature, and substrate sensitivity on the overall reaction were investigated. [ABSTRACT FROM AUTHOR]

This paper discusses the relative advantages of different process options to convert renewable feedstocks (carbohydrates, vegetable oils, terpenes and lignocellulosic materials) into valuable chemicals and polymers. Three process options are considered: (1) via degraded molecules, (2) via platform molecules, (3) via one-pot processes. These routes can all be integrated in a biorefinery scheme which maximises the value derived from biomass. These process options are illustrated by selected examples underlining the green chemistry value of process options 2 and 3. Stress is laid on new value chains adapted to biomass composition and on the use of recyclable heterogeneous catalysts that lead to waste minimisation and decrease the processing cost of renewables. [ABSTRACT FROM AUTHOR]

Due to its advantages of direct heating, high temperature homogeneity, reaction rate enhancement, as well as energy savings, microwave-assisted polymerization has become a fast-growing field of polymer research. This paper reviews microwave-assisted polymerization, with an emphasis on the microwave-assisted ring-opening polymerization, covering both homopolymerization and copolymerization of the cyclic monomers. The advantages of microwave-assisted ring-opening polymerization over conventional polymerization are discussed briefly. [ABSTRACT FROM AUTHOR]

The solid–liquid phase equilibrium (SLE) in binary mixtures that contain a room-temperature ionic liquid, IL, and an organic solvent: {1-ethyl-3-methylimidazolium tosylate, [EMIM][TOS] (1) + cyclohexane, or benzene (2)} and {1,3-dimethylimidazolium methylsulfate, [MMIM][CH3SO4] (1) + hexan-1-ol (2)} have been measured under very high pressures up to about 900 MPa at the temperature range from T = 328 to 363 K. The termostatted apparatus for the measurements of transition pressures from the liquid to the solid state was used. The pressure–temperature–composition relation of the high pressure solid–liquid phase equilibria polynomial based on the Yang model was satisfactorily used. The freezing and melting temperatures at a constant composition increase monotonously with pressure. The high pressure experimental results obtained at isothermal conditions (p–x) were interpolated to well known T–x diagrams. Additionally, the SLE of binary systems {[EMIM][TOS] (1) + cyclohexane, or benzene (2)} at normal pressure have been measured by a dynamic method from 270 K to the melting point of the IL. Experimental solubility results are compared with values calculated by means of the non-random, two-liquid equation (NRTL) utilizing parameters derived from SLE and liquid–liquid equilibria (LLE) results. The experimental results at high pressures were compared for every system to these at normal pressure. The paper includes thermophysical basic characterization of pure ionic liquids obtained via differential scanning calorimetry (DSC), temperatures and enthalpies of melting. The influence of the interaction between the IL and solvent on the solubility at 0.1 MPa and high pressure up to 900 MPa was discussed. [ABSTRACT FROM AUTHOR]

Poly(vinylchloride) (chloroethene) resins have been used for the preparation of plastisols for a number of years. PVC plastisols are dispersions of such resins in liquid plasticisers, the plasticiser having the dual function of imparting softness and flexibility to the final article and for providing a liquid medium for the preparation of the plastisol that enables it to be coated, dipped or sprayed. For many years plastisol viscosity modification has involved the use of various volatile organic compounds (VOCs), which have an impact on their use in the workplace, and can also cause emitted VOCs from the end product. Control of the latter is of particular interest in new developments to combat indoor air quality (IAQ) problems. This paper shows that newly developed PVC resins are capable of producing the correct plastisol viscosity without the need for VOC addition to the plastisol. Moreover, new PVC additive technologies are available which enable end articles to be made from PVC plastisols that show greatly reduced or zero impact on IAQ when tested with newly developed equipment such as the Field and Laboratory Emission Cell (FLEC). [ABSTRACT FROM AUTHOR]

Liquid–liquid equilibria of binary systems containing a room-temperature ionic liquid (1-butyl-3-methylimidazolium 2-(2-methoxyethoxy)-ethylsulfate [BMIM][MDEGSO4], with: a hydrocarbon (n-hexane, cyclohexane, or benzene); a ketone (pentan-3-one, nonan-5-one or cyclopentanone); an alcohol (methanol, ethanol, butan-1-ol or octan-1-ol); 1,1-dimethylpropyl methyl ether or water were measured at normal pressure by a dynamic method from 287 K to the boiling point of the solvent or to 373 K. This paper includes thermophysical basic characterization of pure ionic liquid, obtained via differential scanning calorimetry (DSC), temperature of decomposition, temperature of glass phase transition, and heat capacity at half the Cp extrapolated temperature. The solubility of [BMIM][MDEGSO4] in ketones decreases with an increase of the molecular weight of the ketone and is much higher in cycloketones than in a linear ketone. The solubility of the investigated IL is higher in aromatic hydrocarbons than in cyclic or linear hydrocarbons with the same number of carbon atoms. As a result of its strong interactions with alcohols, [BMIM][MDEGSO4] shows complete miscibility with methanol, ethanol, butan-1-ol and octan-1-ol above 293 K. The experimental results of LLE have been correlated using the binary parameters of the non-random two liquid (NRTL) equation. The average root-mean-square deviation for the equilibrium mole fraction for all the calculated values was found to be 0.0031. [ABSTRACT FROM AUTHOR]

In this paper we focus on the synthesis and use of superacids, in particular 1,1,2,2-tetrafluoroethanesulfonic acid (TFESA), and describe how these can be optimized for reactions of key industrial importance. One area of considerable interest is the field of superacid catalysis and, specifically, the development of safer and more cost-effective acid catalysts. We report a new simplified route for preparation of these acids, making these more readily available and opening up a large number of opportunities. Partially fluorinated superacids offer several advantages over the acids commonly used in catalysis (sulfuric, hydrofluoric acid and aluminium chloride): lower loadings, lower reaction temperatures (leading to increased selectivity), fewer by-products, shorter reaction times and higher throughput. TFESA and its longer chain analogs are much less volatile than triflic acid (CF3SO3H). We tested these superacids in several processes (aromatic alkylation, acylation of arenes, isomerization, oligomerization and the Fries rearrangement). These materials are excellent acid catalysts, comparable to triflic acid, and yet easier to handle. We have also prepared supported versions of these catalysts and introduced the ability to recycle. [ABSTRACT FROM AUTHOR]

We have developed a practical, general protocol for direct C–H azolation reactions of quinoxalin-2(1H)-ones by electro-oxidative cross-coupling. These mild reactions proceed under metal-, oxidant-, and reagent-free conditions to provide synthetically useful azolated quinoxalin-2(1H)-ones. Furthermore, the reactions can be carried out with a pencil lead as an electrode and a 3 V battery as a power source, revealing the remarkable flexibility of this protocol. [ABSTRACT FROM AUTHOR]

Today, most wood adhesives are prepared from fossil-based polymers and contain hazardous components, e.g., formaldehyde. With the growing environmental concern there is an urge to develop bio-based and harmless substitutes. In this study, the ambition is to explore and valorise hemicelluloses, a biproduct from pulping, as the main component in wood adhesives. Wood adhesives were prepared from different sources: xylan from beech wood, hemicellulose-rich liquids obtained from hydrolysis of hardwood, and ultrafiltered softwood hemicellulose recovered from the process water of a thermomechanical pulp mill. Hemicelluloses themselves do not exhibit sufficient bonding performance, but excellent bond strength and water resistance were obtained in combination with poly(vinyl amine). It was also demonstrated that chitosan can be used as a bio-based amino-functional alternative to synthetic poly(vinyl amine), with similar or superior properties. Hemicelluloses alone show insufficient water resistance, but hemicelluloses in combination with chitosan exhibit exceptionally good bonding performance, especially regarding water resistance. Adhesives prepared from liquids rich in hardwood- and softwood hemicelluloses showed similar bond strength in combination with amino-functional polymers (poly(vinyl amine) and chitosan), regardless of their differences in structure. The current study constitutes an example on how sidestreams from the pulp industry in combination with chitosan can be used to substitute fossil-based materials in the quest for a more sustainable society. [ABSTRACT FROM AUTHOR]

Oxidative esterifi cation of alcohols by a single-side organically decorated Anderson-type chrome-based catalyst Copyright of Green Chemistry is the property of Royal Society of Chemistry and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. Green Chemistry Cutting-edge research for a greener sustainable future rsc.li/greenchem ISSN 1463-9262 Volume 23 Number 7 7 April 2021 Pages 2543-2794 PAPER Feng Jiang, Han Yu, Laurent Ruhlmann, Yongge Wei et al. [Extracted from the article]

However, users may print, download, or email articles for individual use. Green Chemistry Cutting-edge research for a greener sustainable future rsc.li/greenchem Volume 23 Number 7 7 April 2021 Pages 2543-2794 ISSN 1463-9262 PAPER Zhicheng Jiang, Javier Remón, Changwei Hu, Bi Shi et al. On the development of chrome-free tanning agents: an advanced Trojan horse strategy using "Al-Zroligosaccharides" produced by the depolymerization and oxidation of biomass Copyright of Green Chemistry is the property of Royal Society of Chemistry and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. [Extracted from the article]

Green Chemistry Cutting-edge research for a greener sustainable future rsc.li/greenchem ISSN 1463-9262 Volume 23 Number 6 21 March 2021 Pages 2187-2542 PAPER Jean-Christophe M. Monbaliu et al. However, users may print, download, or email articles for individual use. A modular, low footprint and scalable fl ow platform for the expedient -aminohydroxylation of enolizable ketones Copyright of Green Chemistry is the property of Royal Society of Chemistry and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. [Extracted from the article]

A well-defi ned lignin-based fi ller for tuning the mechanical properties of polymethyl methacrylate Copyright of Green Chemistry is the property of Royal Society of Chemistry and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. Green Chemistry Cutting-edge research for a greener sustainable future rsc.li/greenchem Volume 23 Number 6 21 March 2021 Pages 2187-2542 ISSN 1463-9262 PAPER Lin Dai, Xiaojun Shen, Chuanling Si et al. However, users may print, download, or email articles for individual use. [Extracted from the article]

Effi cient demethylation of aromatic methyl ethers with HCl in water Copyright of Green Chemistry is the property of Royal Society of Chemistry and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. Green Chemistry Cutting-edge research for a greener sustainable future rsc.li/greenchem Volume 23 Number 5 7 March 2021 Pages 1885-2186 ISSN 1463-9262 PAPER Bert U. W. Maes et al. [Extracted from the article]

Green Chemistry Cutting-edge research for a greener sustainable future rsc.li/greenchem Volume 23 Number 3 7 February 2021 Pages 1065-1390 ISSN 1463-9262 PAPER Gyorgy Szekely et al. However, users may print, download, or email articles for individual use. Hydrophobic thin fi lm composite nanofi ltration membranes derived solely from sustainable sources Copyright of Green Chemistry is the property of Royal Society of Chemistry and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. [Extracted from the article]

Cyclohexene esterifi cation-hydrogenation for effi cient production of cyclohexanol Copyright of Green Chemistry is the property of Royal Society of Chemistry and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. Green Chemistry Cutting-edge research for a greener sustainable future rsc.li/greenchem ISSN 1463-9262 Volume 23 Number 3 7 February 2021 Pages 1065-1390 PAPER Baoning Zong et al. [Extracted from the article]

Ring-opening allylation of cyclic acetals has required stoichiometric amounts of Lewis acids. In this paper, catalytic ring-opening allylation in the presence of silica-alumina is reported. This ring-opening allylation showed high atom economy. Consecutive allylation/hydrolysis using silica-alumina afforded homoallyloxyalcohols in good to high yields. [ABSTRACT FROM AUTHOR]

Substitution of fossil energy sources for bio-based ones will require development of efficient processes that can convert inedible and preferably low-value fractions that currently are not used into high-value products. It is desirable that such processes are developed so that both current logistics and infrastructure can be used. Bark, which is the outer layer of woody biomass, is currently burnt in a low-value process or left in the forests to decay and is therefore considered waste. In this work, birch (Betula pendula) bark was converted to hydrocarbons suitable for use in both road and aviation fuels in two efficient steps. Development of an efficient, recyclable, salt- and metal-free solvent-based system to solubilize birch bark under benign reaction conditions was a key outcome. The obtained gum was composed of organosolv lignin and suberin oligomers and was fully characterized. This gum had unique properties and could be directly processed in a conventional hydroprocessing unit set-up to afford hydrocarbons in the road and aviation fuel ranges. Life cycle assessment was applied to evaluate different scenarios for implementing this technology. When using bark generated as a forestry by-product and current infrastructure in a pulp mill, the process had a favorable low carbon dioxide footprint for biofuel generation. [ABSTRACT FROM AUTHOR]

Nanocellulose is conventionally produced from woody biomass including wood, crops and forest/agricultural residues, by top-down methods. Due to biomass recalcitrance, pretreatment, with a subsequent bleaching process, is mandatory to break down the resistance of the composite for nanocellulose extraction. In the present study, gamma-valerolactone (GVL) pulping without further bleaching/purification was used for producing cellulose nanomaterials from wood. GVL pulp and bleached kraft pulp from Aspen were comparatively studied as starting materials for (2,2,6,6-tetramethylpiperidin-1-yl)oxidanyl (TEMPO) cellulose nanofibril (TCNF) preparation. The TEMPO oxidation process and properties of the as-prepared TCNF solutions and films were studied to investigate the advantages of GVL pulp for TCNF production. There was no difference between nanocellulose prepared from GVL pulp and that from bleached kraft pulp. But, with the GVL pulping process, no subsequent bleaching process was required while the properties of the as-prepared nanocellulose were preserved. [ABSTRACT FROM AUTHOR]

We successfully obtained soda lignin and kraft lignin with high purity and quality by the mild soda pulping process and the harsh kraft process combined with the sequential membrane separation and purification processes. Soda lignin had excellent linear structure with 88% β-O-4 aryl ethers among all the lignin interunit linkages and relatively less phenolic –OH groups as compared with kraft lignin (32% linear β-O-4 and 64% branched C–C), which provide soda lignin with better alignment along polyacrylonitrile (PAN), reduce the entanglement of the fibers, and thus double the tensile stress of the derived carbon fibers when it was blended and electrospun with PAN in the weight ratio of 1/0.25. In particular, higher aromaticity of soda lignin was effectively retained during thermostabilization as compared with kraft lignin, which enabled higher yield of the derived carbon fiber as well as enhanced mechanical performance. The improved mechanical performance of soda lignin-derived carbon fibers could also be evidenced through the increased pre-graphitic turbostratic carbon and crystallite size in the carbon fibers, as revealed by XRD and Raman spectroscopy. [ABSTRACT FROM AUTHOR]

A reductive lignocellulose fractionation in a flow-through system in which pulping and transfer hydrogenolysis steps were separated in time and space has been developed. Without the hydrogenolysis step or addition of trapping agents to the pulping, it is possible to obtain partially depolymerized lignin (21 wt% monophenolic compounds) that is prone to further processing. By applying a transfer hydrogenolysis step 37 wt% yield of lignin derived monophenolic compounds was obtained. Pulp generated in the process was enzymatically hydrolyzed to glucose in 87 wt% yield without prior purification. [ABSTRACT FROM AUTHOR]

The article presents cover page for November 21, 2016 issue of periodical "Green Chemistry" and mentions about a research paper "Structure–property reduced order model for viscosity prediction in single-component CO2binding organic liquids" by Glezakou Vassiliki-Alexandra and others.

The authors reflect on the periodical "Green Chemistry" and RSC Publishing of the Royal Society of Chemistry (RSC). They mention some of the highlights in the 2011 issue of the periodical including on C. J. Li of McGill University who become the periodical's associate editor, an editorial policy in the February 2011 issue which focuses on the use of ionic liquids, and selected papers from the 2nd Asia Pacific Conference on Ionic Liquids. They also present news from the RSC Publishing.

The front cover page of the journal "Green Chemistry" of February 7, 2016 issue is presented which discusses paper by Jeong Yong Lee and Jin Hyeok Kim regarding solar cells.

The inside cover page of the journal "Green Chemistry" for February 7, 2016 issue is presented which discusses a paper by Juan Carlos Colmenares and Yi-Jun Xu related to lignin valorization.

The allylation of European beech wood organosolv lignin (OL) with diallyl carbonate (DAC) in the presence of base catalysts is shown to be an efficient, non-toxic, and sustainable modification technique. Comparative studies of different bases and temperatures were performed to optimize the solvent-free allylation of OL. Up to 90% of the aromatic and aliphatic hydroxyl groups in OL were converted to the respective allyl ethers or allyl carbonates using tetrabutylammonium bromide (TBAB) as recyclable base. The demonstrated strategy allows the introduction of functional groups into the structure of lignin, which will enable further modification. Detailed structural analytics by 31P, 1H, and 13C NMR, as well as IR spectroscopy and detailed mass analysis using SEC–ESI–MS verified the functionalization and delivered insights into the structure of lignin. [ABSTRACT FROM AUTHOR]

This communication presents a process for thermal deoxygenation (TDO) to upgrade levulinic acid whereby levulinic acid is neutralized with calcium hydroxide, and the resulting salt is heated to between 350 °C and 450 °C. The cyclic and aromatic products have low oxygen to carbon ratios, improved energy density, and may be candidates for upgrading to hydrocarbon fuels. The process may be useful for converting biomass-derived levulinic acid in an integrated forest products complex based on a kraft pulp mill which uses a lime cycle to regenerate calcium hydroxide. [ABSTRACT FROM AUTHOR]

Converting pulp mills into forest biorefineries to produce biopower and biomaterials can decrease their environmental impact and increase feasibility at the same time. One of the key challenges to reach this goal is the recovery of lignin from process streams for subsequent utilization in a variety of innovative green processes. This study examines the fundamental chemical structure of lignin recovered from Kraft pulping streams by an acid precipitation/washing methodology. Functional group analysis and molecular weight profiles were determined by NMR and SEC with promising results for future conversions; such as low hydroxyl (oxygen) contents and low molecular weights (∼3000 g mol−1). [ABSTRACT FROM AUTHOR]

As a crucial component of batteries, the binder connects the granular active material and the conductive additive into a whole electrode and attaches to the surface of the current collector through a variety of interactions to maintain the electron/ion transport and the integrity of the electrode during the charge–discharge cycles. However, conventional binders are mostly synthetic polymers with single structures and properties and are not renewable, thus the development of multifunctional green renewable binders derived from biomass materials is attracting increasing attention. The distribution and function of lignocellulose in plants are similar to those of binders in electrodes. They strengthen the structure of the plants via hydrogen bonding, π–π conjugation, hydrophobicity, etc., and maintain the diffusion and transport of molecules, aligning with the criteria for the next generation of battery binders. In the context of the significant impact of binders on the performance of advanced battery systems, recent progress in research on lignocellulose derivative-based binders in various batteries is summarized. The research potential and challenges of lignocellulose and its derivatives as binder materials are discussed, with the hope of shedding light on the rational construction of robust and stable lignocellulose-based binders for high-energy-density batteries. [ABSTRACT FROM AUTHOR]

Lignin is the main component of plant cell walls, conferring upon lignocellulosic biomass both excellent mechanical and barrier properties. At the same time, the considerable number of unsaturated groups and conjugated structures present in lignin render it a promising candidate for applications in the optical domain. In recent years, the development of the optical properties of lignin and lignin-derived optical materials has paved the way for a novel avenue of lignin valorization. This review is concerned with the mechanisms of lignin-derived optical materials, with particular emphasis on the physical and chemical structures that are linked to their optical performance, including UV absorption, photothermal conversion, and photoluminescence. Additionally, the potential applications of these materials in energy storage, bioimaging, structural materials, and photonic crystal are also presented, demonstrating the unique optical properties of lignin. Finally, the challenges and future directions of lignin as an optical material are presented, with the objective of developing lignin into a polymer biobased raw material that can serve advanced emerging industries. [ABSTRACT FROM AUTHOR]

When attempting to obtain light-color lignin from lignocellulosic biomass or industrial lignin, the available options based on chemical or morphological modification suffer from low yield, high cost, and lack of availability at the required scales. In this study, we adopted a polyhydric-alcohol-based deep eutectic solvent (PA-DES) to directly extract light-color lignin from natural biomass, which is even whiter than native cellulolytic enzyme lignin (CEL). The isolated lignin possessed a high recovery yield (97.36%), regular micro-spherical morphology, enriched β-ether linkage of 58/100Ar, low phenolic hydroxyl content of 1.25 mmol g−1, minimal carbonyl content of 0.70 mmol g−1, and less condensed structures, thus yielding a lower content of chromophores. This lignin showed excellent sunscreen effects, which could enhance the SPF of a commercial sunscreen from 15 to 40 with only 5 wt% addition. This study can provide essential guidance for the scale-up production of light-color lignin and obtaining near-complete digestible cellulose for further saccharification. [ABSTRACT FROM AUTHOR]

Electrochemical catalysis emerges as a promising method for lignin depolymerization due to its environmental friendliness and mild reaction condition. Metal oxyhydroxides have displayed appealing electrochemical activity for the oxidation for various biomass substrates. In this study, we prepared different metal (Ni, Co, Mn, Fe, and Cu) oxyhydroxides on nickel foam electrodes through electrodeposition. Their electrochemical properties were characterized and the reactivity towards lignin oxidative cleavage was investigated using lignin model compounds. NiOOH exhibited significantly higher activity for oxidative cleavage of the β-O-4 linkage compared to other metal oxyhydroxides, resulting in a 93% yield of aromatic monomers with 99% selectivity towards benzoic acids. Furthermore, the reconstruction process of the active site NiOOH was revealed by in-situ testing, and the reaction mechanism was explored. The non-phenolic structure underwent Cβ–Cγ/Cβ–O or Cα–Cβ cleavage, predominantly producing benzoic acids, while the phenolic structure was rapidly oxidized into dicarboxylic acids over NiOOH. [ABSTRACT FROM AUTHOR]

The controllable synthesis of high-performance multicolor light-emitting carbon quantum dots (CQDs) that present photoinduced charge transfer and reservoir is of great concern for advancing their optical physics with versatile functions. In view of the incorporation of conjugated structures into phenylpropanoid building blocks, renewable lignin with abundant functional groups (e.g., hydroxyl, carboxyl, and methoxyl) is well-suited to prepare polycyclic aromatic CQDs. Herein, we propose a universal acidic approach to fabricating multicolor lignin-derived CQDs with heteroatom-doping for double-edged water decontamination involving switchable metal-ions sensing and photocatalytic antibiotic abatement. The N,S co-doped multicolor CQDs with a size distribution of 3.84–5.85 nm facilitate the selective identification abilities of the intricate metal-ion systems of Fe3+, Ag+, Cu2+, and/or Co2+ in a broad response range with excellent accuracy and the limit of detection of 0.55–2.77 μM. The tunable factors of quantum size, surface potential, electrostatic attraction, molecular state, and cation–π interactions that endow the unique CQDs with optical–structure–performance relationships provoked by lignin-oxidized cleavage are underlined. Taking advantage of the Fe-modified yellow-emitting CQDs with high yield, an efficient photocatalytic persulfate activation is proposed to mineralize tetracycline (∼80% removal efficiency at an ultrahigh concentration of 50 mg L−1) under visible-light irradiation. Benefitting from the successful armoring of Fe into the sp2 graphitic CQD structure with the Fe–OH and Fe–N complexes, the electron transition can be expedited via available light-harvesting behavior, enhanced photoactive sites, and Fe-ion durability. The synergetic photoredox manner of extracting electrons/holes maneuvers the generation of free radicals and singlet-oxygen, wherein the produced ˙O2− and surface charge migration-dominant photocatalytic reaction. With the perspective of achieving waste-treats-pollutant, this work not only delivers the rationally engineered lignin valorization but also highlights the well-defined CQDs in multifunctional water purification. [ABSTRACT FROM AUTHOR]

Active packaging techniques such as oxygen scavenging have gained much attention from consumers in the past few years. It would be of great advantage if metal-based scavengers were replaced with plantbased sustainable and biodegradable materials. In this work, plant-based natural rubber latex was explored as a potential oxygen-scavenging material in combination with polyvinyl alcohol (PVA) to fabricate potentially biodegradable films. PVA and NRL were taken in different ratios for film formation and analyzed for their physical, mechanical, thermal, and moisture barrier properties along with their biodegradability as well as oxygen scavenging capacity and rate. Apparently, the film with two parts of NRL exhibited the highest scavenging capacity with a rate of 1045 mL O2 per g and 95 mL O2 per g per day at 60 °C and 120 s of UV-C exposure time, respectively, and a water contact angle of 65.18°. Alternatively, the same film has the lowest tensile strength of 10.36 MPa and did not degrade even after 90 days. The addition of two parts of PVA yielded the highest tensile strength of 24.32 MPa and faster degradation in 60 days. A higher water transmission rate of 24.2 g per m² per day was seen in the film with equal parts of PVA and NRL. After oxidation, all the films showed a significant color change compared to the color before oxidation. The films turned light brown from pale yellow and had the highest total color change of 31.27. This change in color can be a visual indication of oxygen scavenging by NRL. These results suggest that the fabricated potentially biodegradable PVA and NRL composite films can effectively scavenge oxygen with good mechanical and barrier properties and can hence be used in food packaging. [ABSTRACT FROM AUTHOR]

The utilization of lignin in material fabrication has garnered significant attention despite its complex structure that greatly limits its applications. This study reports a green method for grading and modifying lignin to prepare stable hydrophobic coatings via the solvent/anti-solvent (ethanol/water) self-assembly method. First, the formic acid lignin particle (FLP) is prepared and the underlying mechanism is primarily ascribed to the hydrogen bonding, π–π interactions among aromatic groups within and between molecules, and hydrophobic interactions. The lignin nanoparticles were utilized to chelate with metal ions (iron) in order to obtain the stable hydrophobic coatings using the special nanostructures of FLP. This hydrophobic coating could be applied to different substrates (blocks, straw, and fabric). The cotton fabric exhibited an initial water contact angle (WCA) that increased from 73.4° to 129.6°, and excellent chemical and physical hydrophobic performance. Moreover, this coating has strong self-cleaning ability and could be used for oil–water separation. In this newly proposed fabrication, ethanol can be recovered in the preparation of lignin nanoparticles, which makes the green and facile preparation of a stable hydrophobic coating possible. Additionally, this work is important in upgrading formic acid lignin by controlling the polarity into value-added hydrophobic materials via green classification. [ABSTRACT FROM AUTHOR]

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]

Thermoplastic starch (TPS) has acquired considerable attention and many efforts have been devoted to its application in many areas, such as food packaging, waterborne coatings, gas barriers, and energy storage and generation. Differing from other thermoplastic polymers, the manufacturing of TPS requires appropriate solvents for granule disruption, which contribute to the dissociation of the double helical structure of starch granules and the reconstitution of hydrogen bond crosslinking between solvent molecules and starch chains. Today, state-of-the-art approaches and techniques are commonly found in literature. However, in many cases, there is no clear definition or guidelines on what aspects are involved and what roles hydrogen bonds play in the synthesis of TPS. This review focuses on classifying, differentiating, and correlating the existing concepts using recent literature reports to provide readers with a general insight into the thermodynamic and kinetic aspects of TPS green manufacturing. Moreover, this review summarizes the potential of green solvents and green polymers to prepare TPS-based materials for fighting against post-consumer waste and expanding their application sphere. Furthermore, next generation TPS, multifunctional starch organic gel, and its fabrication strategies and applications in power sources for wearable electronics as well as efficient energy storage and multimodal stimulus-responsive sensors are elaborated in this review. Eventually, a good comprehension of suggestions and outlooks concerning the applications of TPS-based materials presented would contribute to the development of new complex, functional materials. [ABSTRACT FROM AUTHOR]

This tutorial review aims to describe the status of the scaling up of organosolv treatment. It is a process where various lignocellulosic materials are fractionated, selective depolymerization mechanisms are catalyzed, and their main components (polysaccharides, lignin and extractives) can be extracted, separated and isolated using liquid organic solvents such as alcohols, ketones and proton-donating acid molecules. Organosolv fractionation can be applied to several renewable biomasses, allows the production of pure species systems to prepare valuable chemicals, polymers and biomaterial compositions with a related environmental impact, lower than that of classical industrial plants, and optimizes the resource carbon efficiency. However, the high energy consumption for the recovery after dissolution, input costs and feedstock flexibility robustness are slowing down the piloting of commercial operations. As a critical indicator evaluation, a summary of reasons why engineering organosolv is still extremely interesting, together with an overview of the most important organosolv technologies, describing current equipment scale range economics, limitations and market research opportunities, is presented in detail. A variety of sources (wood, straw, bagasse, wastes...), media (water, methanol, ethanol, formates, acetates...) and products (biogas, bioethanol, (nano)cellulose, glucose, furans...) are comparatively benchmarked. Existing (model) validated, demonstrational or patented configurations are collected, listing strengths as well as challenges. [ABSTRACT FROM AUTHOR]

Polyelectrolytes with ultra-low glass transition temperatures (Tg) are still a rarity. Herein, we report a series of free-flowing lignin polyelectrolytes with ultra-low Tg in the range of −57–9 °C, namely, deep eutectic supramolecular lignin (DESL). The enabling key principle is to couple the eutectic strategy with supramolecular polymerization, bypassing the exclusive reliance on the large size and flexible cation/anion pairs for flowable polyelectrolytes. Following this principle, various sugars have been successfully integrated with lignosulfonic acid via multiple hydrogen bondings, allowing for bulk yet free-flowing supramolecular materials. These DESLs are processible, adaptive, and compatible to serve as macromolecular solvents and are distinct from traditional polyelectrolyte solutions or chemical modification derivatives. The robustness and versatility of our approach provide a fresh opportunity for booming polyelectrolyte utilization, opening access to a yet unknown fluidic material class. [ABSTRACT FROM AUTHOR]

Developing green and effective solvents is of significant importance for the utilization of lignin. Here, we demonstrated that biomass-derived polar aprotic solvents can serve as co-solvents with poly-deep eutectic solvents (PDESs) for massively dissolving various lignin samples at room temperature. The pristine PDESs were composed of polyethylene glycol derivatives and levulinic acid, while all of them exhibited poor solubility to enzymatic hydrolysis lignin (EHL), sodium lignosulfonate (LS), and organosolv lignin (OL). With the further introduction of polar aprotic solvents, including dimethylisosorbide (DMI), dihydrolevoglucosenone (Cyrene), N-formylmorpholine (NFM), and propylene carbonate (PC), synergy between the polar aprotic solvents and PDESs dramatically increased lignin solubility to 96.82%. PC and DMI were more suitable for assisting the solubilization of EHL and OL, while Cyrene and PC were targeted at the solubilization of LS in PDESs, respectively. Moreover, a new unified co-solvent solubilization mechanism relative to the Kamlet–Taft empirical parameters was proposed. The novel polar aprotic/PDES systems provide a new avenue for boosting the high utilization of lignin. [ABSTRACT FROM AUTHOR]

Developing aqueous stable and catalytic Ti3C2Tx MXene suspensions remains a grand challenge. MXene nanosheets always undergo rapid degradation when exposed to water and oxygen, and the incorporation of reducing or capping agents may deteriorate the intrinsic characteristics of MXenes. Here, we coupled dialdehyde xylan (DAX) with MXene nanosheets to significantly increase the long-term storage of MXene in an aqueous solution (>3 months) with a dramatic enhancement of their room temperature catalytic activity for ultrafast gelation. DAX can form thick and smooth layers on the nanosheets via multiple hydrogen bonds, providing a reduction environment to prevent the occurrence of oxidation. Meanwhile, DAX can accelerate the generation of free radicals from the potassium persulfate (KPS)/MXene pair, reducing the polymerization time of vinyl monomers from ∼30 min to ∼90 s. Moreover, the DAX layer is capable of serving as additional crosslinks by leveraging Schiff base bonds with chitosan (CS), with the elongation at break increasing from 100% to 909%. The resultant MXene-based hydrogel can be further explored as a sustainable sensor for real-time physical signal monitoring. This work offers an enticing prospect for the development of eco-friendly and high-performance MXene-based materials. [ABSTRACT FROM AUTHOR]

The high overpotential of the oxygen evolution reaction (OER) and the undesirable chlorine evolution reaction (ClER) severely limit the hydrogen production efficiency of seawater electrolysis. The organic electrooxidation reactions, involving C–H bond oxidation with low bond dissociation energy in the rate-limiting step, can possess lower oxidation potential than the OER as well as prevent the ClER. Herein, we demonstrate a strategy for replacing the sluggish OER by thermodynamically favorable biomass oxidation for scaling up the electrolysis of alkaline seawater. A xylose electrooxidation reaction (XOR) holds great promise for superseding the OER in seawater electrolysis, which not only simultaneously produces valuable formic acid and hydrogen, but also improves energy utilization. By utilizing NiCoP metal phosphide as the bifunctional electrode, the XOR shows an apparent overpotential reduction of 290 mV at 100 mA cm−2 as compared with the OER in the alkaline seawater electrolyte. Furthermore, the xylose-assisted seawater electrolysis exhibits a high formic acid selectivity of at least 94.6% and a high hydrogen production rate of 150 mL cm−2. This work provides a universal and an effective pathway for hydrogen production from seawater and biomass upgrading. [ABSTRACT FROM AUTHOR]

The valorization of abundant agrowastes into chemicals and advanced materials is of key importance in the context of the circular bioeconomy and biorefinery. Herein, we report the ionothermal carbonization (ITC) of sugarcane bagasse, a fibrous residue made of lignocellulose, to engineer advanced carbonaceous materials, namely ionochars. We prepared a series of imidazolium tetrachloroferrate ionic liquids (IL) bearing modular substituents, e.g., alkyl chains with different lengths or benzyl groups. The effect of the cation on both textural and morphological properties is highlighted. Ionochars with high specific surface area (up to 800 m2 g−1), tuneable pore volume (up to 0.8 cm3 g−1), singular nanostructures and adjustable CO2 uptake/retention were obtained. [ABSTRACT FROM AUTHOR]

Carbon reduction targets urge people to develop potential alternatives to traditional energy-intensive kraft pulping. To address this need, this work reported a sustainable pulping technology for eucalyptus slabs based on a deep eutectic solvent (DES) consisting of benzyltriethylammonium chloride (BTEAC) and formic acid (FA). Under mild cooking conditions (T = 130 °C, t = 2.0 h), the pulp yield reached 53.83%, and fibers had a length of 0.65 mm and a fines content of 6.21%. The physical properties of DES pulp were similar to those made by other traditional processes. Meanwhile, approximately 85% of FA and 92% of BTEAC could be reused in the improved chemical recovery process, and the cooking efficiency of recycled DES was largely maintained after 5 times of recycling. Moreover, compared with the kraft process, DES pulping could extract more lignin with high purity and narrow molecular weight distribution. The results proved that this technology could produce high-quality pulp and lignin by-products simultaneously with less energy and chemical consumption. [ABSTRACT FROM AUTHOR]

Blending lignin with industrial degradable polyester is a sustainable and economically competitive strategy for biodegradable plastic production, but the miscibility of the composite remains a great challenge. In this study, the screened lignin with low molecular weight, uniform structure and rich hydroxyl groups was completely miscible with poly(butylene adipate-co-terephthalate) (PBAT). The low molecular weight of ethyl acetate dissolved lignin (EL) was critical for decreasing its glass transition temperature and steric hindrance, and the abundance of functional groups offered plenty of sites for forming strong intermolecular interactions between EL and PBAT. The intermolecular hydrogen bonds and π–π interactions of EL and PBAT promoted the dissociation of the lignin complex, thereby enhancing the plasticizing effect of PBAT on lignin. The PBAT/EL composite film with 50 wt% EL loading (P/EL50) displayed high tensile strength (24.7 MPa) and elongation at break (494.7%), being ahead of the currently reported PBAT composite films with high lignin addition. The yield strength increased threefold due to the rigid lignin structure and the intrinsic multiple noncovalent interactions. Moreover, compared to pure PBAT films, P/EL50 films exhibited a higher sensitivity of the mechanical performance to temperature and had a 22.9% cost reduction. [ABSTRACT FROM AUTHOR]