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The polymerization of a bio-based terpene-derived monomer, sobrerol methacrylate (SobMA), was evaluated in the design of polymeric nanoparticles (nanolatexes). Their synthesis was accomplished by using emulsion polymerization, either by free-radical polymerization in the presence of a cationic surfactant or a cationic macroRAFT agent by employing RAFT-mediated polymerization-induced self-assembly (PISA). By tuning the length of the hydrophobic polymer, it was possible to control the nanoparticle size between 70 and 110 nm. The average size of the latexes in both wet and dry state were investigated by microscopy imaging and dynamic light scattering (DLS). Additionally, SobMA was successfully copolymerized with butyl methacrylate (BMA) targeting soft-core nanolatexes. The comparison of the kinetic profile of the cationically stabilized nanolatexes highlighted the differences of both processes. The SobMA-based nanolatexes yielded high Tg ∼ 120 °C, while the copolymer sample exhibited a lower Tg ∼ 50 °C, as assessed by Differential Scanning Calorimetry (DSC). Thereafter, the nanolatexes were adsorbed onto cellulose (filter paper), where they were annealed at elevated temperatures to result in polymeric coatings. Their morphologies were analysed by Field Emission Scanning Electron Microscopy (FE-SEM) and compared to a commercial sulfate polystyrene latex (PS latex). By microscopic investigation the film formation mechanism could be unravelled. Water contact angle (CA) measurements verified the transition from a hydrophilic to a hydrophobic surface after film formation had occured. The obtained results are promising for the toolbox of bio–based building blocks, focused on sobrerol-based monomers, to be used in emulsion polymerizations either for tailored PISA–latexes or facile conventional latex formation, in order to replace methyl methacrylate or other high Tg-monomers. [ABSTRACT FROM AUTHOR]

Life cycle thinking analysis (LCT) was conducted on the production of vanillin via bamboo wet air oxidation compared to vanillin production from crude oil or Kraft lignin. Synthetic vanillin has been produced from crude oil and paper pulping process "waste" for nearly a century. Bamboo is a quick growing, lignin rich biomass with the potential for the generation of aromatic products including vanillin. Wet air oxidation experiments were performed, using CuSO4 and Fe2O3 catalysts in alkaine environments, on raw bamboo with the purpose of determining the aromatic compound yields in order to investigate bamboo as a potential source of fine chemical products. From the LCT approach, production of vanillin from Kraft Lignin compared to crude oil has a lower environmental impact across all categories per kg produced of vanillin. Kraft lignin production of vanillin is shown to reduce smog formation and CO2 emissions from non energy sources to negligible levels while decreasing acidification potential by 6.8 times, toxic inhalation by 1.3 times and toxic ingestion potential by 0.3 times compared to crude oil. The proposed bamboo oxidation route has the potential to have the least environmental impact with negligible impact on smog formation potential and ozone depletion potential if a green polar extractive solvent can be utilised in future while also decreasing toxicity by inhalation by a further 115 fold and ingestion by 9458 fold. This work has the potential to contribute to the United Nation Sustainable Development Goal for Responsible Consumption and Production, Goal 12. [ABSTRACT FROM AUTHOR]

The quest for the sustainable energy transition requires replacing fossil fuels by renewable electricity (RE). Systems of energy supply consist of both electrons and molecules as energy carriers. It is thus essential to interconvert both types of carriers. Capitalizing on the intrinsic efficiency of using electrons it is desirable to electrify in the sustainable system more end energy applications than in the fossil system being fully based upon molecular carriers. This does not eliminate the need to retain molecules as energy carriers in a substantial fraction of a whole energy system. The application "energy storage" as example compensates the volatility of RE and is thus critical to any energy transition. Chemical energy conversion (CEC) is the critical science and technology to eliminate fossil fuels, to create circular energy economies and to enable global exchange of RE. This paper describes generic structural features and dimensions of CEC. [ABSTRACT FROM AUTHOR]

Keratin dissolution is the first step toward reusing protein-rich biomass such as waste wool, hair, and feather. This paper reports an efficient and environmentally friendly method for the complete recycling of waste wool using a mixture of lactic acid and L -cysteine as a new green deep eutectic solvent (DES) for isolation of keratin. The dissolution time for a 90% dissolubility was 3.5 hours at 95 °C where 22 mg of wool was dissolved per 1 g of the DES. Keratin was obtained after dialysis of the DES mixture followed by lyophilization. In comparison with the raw wool, the α-helix content of keratin decreased while its β content increased. The keratin isolation with the proposed DES only requires water, L -cysteine, and lactic acid and does not require conventional chemicals such as urea, sodium sulfite, and sodium hydroxide. [ABSTRACT FROM AUTHOR]

Eutectic Hardeners (EH) are multi component mixtures that activate one or more of their constituents for curing at low temperatures and are characterized by a low melting point. In this paper, natural acids and their mixtures (Citric Acid (CA), Malic Acid (MA), and Tartaric Acid (TA)) are used in conjunction with the liquefactor Ethyl Lactate (EL) to cure epoxidized linseed oil (ELO). Their influence on curing speed and final material properties are investigated. Mixtures with MA proved to have a lower viscosity, which is beneficial for the preparation of homogenous samples, but showed slightly diminished tensile properties compared to materials cured with only CA. TA had an increased reaction speed thanks to a lower pKa value and the final material properties of a CATA mixture with small amounts of TA were found to have improved toughness and tensile strength. [ABSTRACT FROM AUTHOR]

This research work applied the hydrothermal process for the surface treatment of ceramic fibres which are integrated into ceramic matrix composites (CMCs). In the conventional process, the main step consists of dissolving the oxidised phases at the fibre surface using strong acids. As a consequence, the chemical homogeneity of the surface is improved and a microporous carbon (C) film is generated at the fibre surface. The C-rich surface enhances the compatibility of the fibre with the pyrocarbon interphase that is deposited on the fibres prior to matrix deposition when processing CMCs. This paper shows the possibility of substituting this conventional process using strong acids by hydrothermal treatment. Indeed, as water displays tunable physico-chemical properties as a function of temperature and pressure, it is possible to recover fibres demonstrating similar surface characteristics to the ones obtained after the reference acid-based treatment. The efficiency of the hydrothermal treatment is assessed through optimised surface properties obtained after one single-step process operating in a semi-continuous mode. Then, a mechanism investigation reveals a selective attack of the Si atoms contained in the fibre via a hydrolysis reaction. Besides, it is denoted that the process follows zero order kinetics. This allows fine control of the fiber surface properties to obtain CMCs with high thermomechanical performance. [ABSTRACT FROM AUTHOR]

Supercritical methanol depolymerization and hydrodeoxygenation (SCM-DHDO) is a process to produce fuel from biomass with supercritical methanol and CuMgAlOx catalyst. Previous research has shown that SCM-DHDO can convert cellulose, lignin and whole biomass feedstock in a single reaction step. In this paper, we show that SCM-DHDO can convert pyrolytic lignin derived from pyrolysis oil at approximately 50% carbon yield to an upgraded oil product. The upgraded oil mainly contains lignin monomers and dimers while an additional 50% of the carbon was converted into undesired products including methanol, insoluble pyrolytic lignin and coke. We demonstrated that after a 4 h SCM-DHDO reaction the pyrolytic lignin molecular weight did not significantly change, but the ketones, acids and aldehydes in the pyrolytic lignin were completely converted. Increasing the reaction time of SCM-DHDO reaction from 2 to 10 h increased the lignin monomer and dimer yield. The reduced CuAlMgOx catalyst hydrogenated 57.4% of the aromatic carbons to aliphatic carbons and removed 64% of the oxygen. However, the product oil could still not be distilled because of the thermal instability of the upgraded pyrolytic lignin. [ABSTRACT FROM AUTHOR]

The sufficient utilization and transformation of cellulose into cellulose derivatives has always attracted considerable attention due to its renewability, biodegradability, non-toxicity, abundance, and low cost. However, the extensive utilization of cellulose is actually hampered by its well-known insolubility in water and most organic solvents. Hence, the development of efficient solvents for cellulose has been going on to date. Among various solvents, ionic liquids (ILs), particularly carboxylate ILs, have been found to be effective solvents for cellulose. The detailed knowledge of the application of non-carboxylate ILs in cellulose dissolution and processing has been overviewed in several literature studies published recently. However, detailed overviews of the application of carboxylate ILs in cellulose dissolution and processing are scarce. Therefore, this review summarizes the dissolution performance, possible dissolution mechanism, and dissolution thermodynamic of cellulose in various carboxylate IL solvent systems including neat carboxylate ILs and carboxylate IL + cosolvent. Meanwhile, the relationships of Kamlet–Taft parameters (α, β, and π*), viscosity and conductivity with cellulose dissolution as well as microwave and ultrasonication application in cellulose dissolution are also reviewed. Moreover, the properties of the regenerated cellulose film, aerogel, and fiber materials have been discussed. In addition, the thermal properties of carboxylate ILs are also concluded in this review for their safe use. Finally, the existing problems are discussed and future prospects are given. We hope that this paper would be helpful for the design of desired carboxylate IL solvent systems and practical applications in cellulose conversion into valuable products. [ABSTRACT FROM AUTHOR]

Bacterial cellulose (BC) with its ultrafine nano-reticular structure may provide great support and distribution to metal nanoparticles. In this study, polyethylenimine was introduced into dialdehyde BC to improve the binding stability between BC and palladium (Pd) nanoparticles. The Pd nanoparticle-embedded BC (Pd-BC) was further composited with plant fibers to fabricate a paper-like “dip-catalyst” through a paper handsheet making method. This catalyst has structural features including the fact that PEI-BC provides a great distribution and binding stability to Pd particles, while plant fibers as a supporting component may reduce the cost of fabrication, provide mechanical strength, and improve the contact between the reactants and Pd particles due to their porosity. The dip-catalyst or catalyst sheet was employed in the Suzuki–Miyaura reaction, providing a high reaction rate, a yield of nearly 100% and a high turnover frequency (TOF). It demonstrated an easy reusability and an extensive recycling capability with the same catalyst sheet being used 26 times and still having a yield of nearly 90%. This catalyst sheet produced from sustainable materials is expected to play an important role in organic synthesis. [ABSTRACT FROM AUTHOR]

A new vision of using carbon dioxide (CO2) catalytic processing of oleic acid into C8–C15 alkanes over a nano-nickel/zeolite catalyst is reported in this paper. The inherent and essential reasons which make this achievable are clearly resolved by using totally new catalytic reaction pathways of oleic acid transformation in a CO2 atmosphere. The yield of C8–C15 ingredients reaches 73.10 mol% in a CO2 atmosphere, which is much higher than the 49.67 mol% yield obtained in a hydrogen (H2) atmosphere. In the absence of an external H2 source, products which are similar to aviation fuel are generated where aromatization of propene (C3H6) oxidative dehydrogenation (ODH) involving CO2 and propane (C3H8) and hydrogen transfer reactions are found to account for hydrogen liberation in oleic acid and achieve its re-arrangement in the final alkane products. The reaction pathway in the CO2 atmosphere is significantly different from that in the H2 atmosphere, as shown by the presence of 8-heptadecene, γ-stearolactone, and 3-heptadecene as reaction intermediates, as well as a CO formation pathway. Because of the highly dispersed Ni metal center on the zeolite support, H2 spillover is observed in the H2 atmosphere, which inhibits the production of short-chain alkanes and reveals the inherent disadvantage of using H2. The CO2 processing of oleic acid described in this paper will significantly contribute to future CO2 utilization chemistry and provide an economical and promising approach for the production of sustainable alkane products which are similar to aviation fuel. [ABSTRACT FROM AUTHOR]

Within the current global climate, precedence has been set on achieving greater sustainable development within process industries. The ammonia process (BAU case) has been labelled as a significant greenhouse gas (GHG) producer-mainly due to high energy demand and CO2 emissions. This places the process under substantial scrutiny in terms of its climate change impacts and thus, provides a strong case study for viable transition towards greater sustainable operations. Here we examine, for the first time, sustainable eco-park designs for the diversification of the ammonia industry utilizing industrial symbiosis. The network considers several carbon capture and utilization (CCU) applications as well as ammonia (NH3) integration to produce the following downstream products: NH3, urea, Urea Ammonium Nitrate (UAN), Melamine (Mel) and Methanol (MeOH). Our results demonstrate improved energy efficiency with the inclusion of MeOH while UAN decreases net energy demand. Economically, the incorporation of MeOH gave attractive returns on investment due to increased productivity. Insights into environmental sustainability, through the assessment of Planetary Boundaries (PBs), revealed high risk operations aligned to climate change and ocean acidification earth systems linked to BAU operations. These impacts improved considerably with the addition of MeOH, resulting in safe operations of the ammonia process, attributed to increased waste recovery. These results were further supported using Life Cycle Sustainability Assessments, highlighting the potential of the BAU + urea + UAN + Mel + MeOH eco-park design for enhanced sustainable development. Overall, the findings of our paper suggest that upcoming and existing ammonia facilities can exploit industrial symbiosis to achieve greater sustainability through diversification of process operations. [ABSTRACT FROM AUTHOR]

Owing to the inert nature of the pyridine ring and high activity of iminyl radicals, the reaction between pyridine and iminyl radicals remains a significant challenge. In this paper, we report the synthesis of sulfide imidazo[1,2-a]pyridines from vinyl azides, thiophenols, and pyridines via a radical [3 + 2] cycloaddition. Promoting inert pyridine and highly active iminyl radicals to participate in this intermolecular cycloaddition process is the striking feature of this protocol. The excellent antitumor activity of the prepared sulfide imidazopyridine scaffold demonstrated the synthetic utility of the developed synthetic protocol. [ABSTRACT FROM AUTHOR]

Most commercial starch esters are currently produced under harsh alkaline conditions. Triggered by environmental concerns, organocatalysis has recently emerged as a sustainable alternative offering mild reaction conditions, reduced waste formation and high selectivity. In this paper, the catalytic effect of several organic acids for the heterogeneous esterification of corn starch is compared, followed by a systematic analysis of tartaric acid-catalysed reactions on substrates with varying amylose/amylopectin ratios using a range of carboxylic acid and anhydride reagents of different chain lengths. Reaction conditions (temperature, time and catalyst concentration) were optimized and products were thoroughly characterized in terms of degree of substitution, chemical structure, morphology, moisture uptake and thermal stability. Organocatalysis proved to be competitive with conventional, alkaline methods. Our study also demonstrates that sustainability can further be improved by the direct recycling of the liquid phase. Notably, however, the tartaric acid catalyst participates in substitution reactions with starch. Despite recent claims to the opposite, reactivity of the carboxylic acid derivatives is primarily determined by carbon chain-length, while reagent type and therefore water content in the reaction mixture has a crucial effect on the final properties of the product. Our results highlight the importance of selecting appropriate synthesis methods and conditions as well as characterization techniques in order to create materials with the desired property profile according to the targeted application. [ABSTRACT FROM AUTHOR]

Carbon capture, utilization and storage (CCUS) have been projected by the power and industrial sectors to play a vital role towards net-zero greenhouse gas emissions. In this study, we aim to explore the feasibility of a global chemical industry that fully relies on CO2 as its carbon source in 2050. We project the global annual CO2 demand as chemical feedstock to be 2.2–3.1 gigatonnes (Gt), well within the possible range of supply (5.2–13.9 Gt) from the power, cement, steel, and kraft pulp sectors. Hence, feedstock availability is not a constraint factor for the transition towards a fully CO2-based chemical industry on the global basis, with the exception of few regions that could face local supply shortages, such as the Middle East. We further conduct life cycle assessment to examine the environmental benefits on climate change and the trade-offs of particulate matter-related health impacts induced by carbon capture. We conclude that CO2 captured from solid biomass-fired power plants and kraft pulp mills in Europe would have the least environmental and health impacts, and that India and China should prioritize low-impact regional electricity supply before a large-scale deployment of CCUS. Finally, two bottom-up case studies of China and the Middle East illustrate how the total regional environmental and health impacts from carbon capture can be minimized by optimizing its supply sources and transport, requiring cross-sectoral cooperation and early planning of infrastructure. Overall, capture and utilization of unabatable industrial waste CO2 as chemical feedstock can be a feasible way for the net-zero transition of the industry, while concerted efforts are yet needed to build up the carbon-capture-and-utilization value chain around the world. [ABSTRACT FROM AUTHOR]

An efficient one-pot, three-component synthesis of highly substituted bicyclic pyridines containing a ring-junction nitrogen, starting from simple and readily available materials, is described. Cyclocondensation of heterocyclic ketene aminals (HKAs), triethoxymethane, and active methylene compounds by refluxing under solvent-free and catalyst-free conditions, provided bicyclic pyridines in excellent yields. [ABSTRACT FROM AUTHOR]

para-Xylene (PX) is a basic building block of polyethylene terephthalate, which is currently produced from petroleum resources. Developing a renewable route to PX is highly desirable to address both economic and environmental concerns. Several attempts used noble metal catalysts, e.g. Pd/Al2O3, to synthesize PX from biomass-derived 4-methyl-3-cyclohexene-1-carboxaldehyde (4-MCHCA), but suffered from a severe decarbonylation reaction, resulting in toluene as the main product. In this paper, we report an FeOx modification strategy to suppress the decarbonylation reaction on a Pd/Al2O3 catalyst, leading to a drastic shift in selectivity towards PX with a yield up to 81% via a cascade dehydroaromatization–hydrodeoxygenation (DHA–HDO) pathway. Characterization and control experiments revealed that the electron density of Pd sites decreased in an FeOx-modified Pd/Al2O3 catalyst compared to Pd/Al2O3, thus tuning the preferential adsorption mode of the substrate from η2-(C,O), the key transition state of the decarbonylation reaction, to the η1-(O) mode that favors the hydrodeoxygenation process. Notably, this designed catalyst is highly stable and is readily applicable in the selective synthesis of a broad range of desired aromatic chemicals via the same DHA–HDO pathway from cyclohex-3-enecarbaldehyde derivatives. Overall, this work develops a controllable catalyst modification strategy that tailors an efficient catalyst for petroleum-independent bio-PX synthesis. [ABSTRACT FROM AUTHOR]

Organic solvent nanofiltration (OSN) is an energy-efficient separation technique that has the potential to improve environmental sustainability in many industrial sectors, including food processing, biorefineries, and in the production of pharmaceuticals, fine chemicals and petrochemicals. Some issues, however, hinder the pace of development of this sustainable separation method that could ultimately provide green manufacturing strategies. These issues include lack of clear experimental designs, explicit experimental protocols, comparable performance data and long-term performance tests of membranes at industrially relevant solute concentrations in OSN studies. Here, we report on a survey of the OSN research community and on a critical assessment of 177 journal papers published from 2015 to 2019 to determine how the scientific value and industrial impact of OSN studies can be improved. Based on the results of our survey and literature analysis, we crafted a series of best-practice recommendations for researchers reporting data on membrane fabrication, membrane materials characterization and filtration performance, process integration and fundamental studies. [ABSTRACT FROM AUTHOR]

Transparent, flexible, and eco-friendly touch sensors are important components for next-generation green electronics such as wearable sensors and e-skins. However, most current touch sensors, which are based on plastics or glass substrates and indium tin oxide or metal microelectrodes, are not environmentally friendly, as well as being difficult to recycle and expensive. Here, we demonstrate that a green, transparent, flexible, and recyclable nanopaper-based touch sensor (NPTS) can be fabricated via inkjet printing a conductive polymer, poly(3,4-ethylene dioxythiophene)-doped polystyrene sulfonate (PEDOT:PSS), on cellulose nanofibril paper. The materials cost of a single-keypad NPTS with a size of 3.5 cm × 2.5 cm × 0.05 mm is only $0.060. Good printability, excellent transparency (80% at 400 nm), and high conductivity (1360 S cm−1) were achieved with the PEDOT:PSS microelectrodes when using a newly developed, eco-friendly water-based ink formulation. It takes only 3–4 weeks for the NPTS to degrade completely in natural soil. A four-keypad NPTS was demonstrated by interfacing with the Arduino UNO development board. Folding, bending, and multiple finger-touch trials caused only slight capacitive changes to the NPTS, with no loss of function. The facile fabrication of the NPTS will be invaluable for many practical applications where eco-friendly, transparent, flexible, durable, recyclable, and economical touch-control is required. [ABSTRACT FROM AUTHOR]

Waterborne pressure-sensitive adhesives (PSAs) containing degradable crosslinked chains that enable easy removability of the adhesive tape have been successfully synthesized. Symmetric and asymmetric degradable oligoester crosslinkers of variable chain length have been synthesized by ring opening polymerization (ROP) of ε-caprolactone and lactide. The oligoester crosslinkers have been incorporated into a conventional waterborne PSA formulation to demonstrate the possibility of introducing degradability by hydrolysis of crosslinking chains to PSAs. The adhesive films present good adhesive properties, but it is remarkable that when exposed to basic conditions their adhesion is substantially reduced within short times and hence the PSAs can easily be removed (much easier than if conventional crosslinkers are used). The degradation of the ester group of the crosslinkers is responsible for the loss of adhesion properties making this class of degradable waterborne PSAs excellent candidates as removable adhesives. These PSAs might have a strong impact on the sustainability of the cleaning process of glass bottles (or other substrates) by reducing the energy and solvent consumption. [ABSTRACT FROM AUTHOR]

This paper presents a facile strategy to activate citric acid (CA) for room temperature curing. The high melting point of CA is reduced by preparing a eutectic mixture of CA and ethyl lactate (EL). By using CA and EL in the molar ratio of 1 : 1, the melting point of CA can be reduced from 200 °C to −50 °C. This eutectic mixture is then used to cure epoxidized linseed oil (ELO) at room temperature and higher temperatures. Room temperature curing was demonstrated by studying the evolution of the storage and loss modulus as a function of time, as well as by monitoring the changes in the glass transition temperature (Tg) with time. By isothermal curing experiments, the activation energy was determined to be 73 kJ mol−1. A comparison between the performance of the samples prepared at room temperature and that of samples prepared at higher temperatures was made, and it was found that full curing cannot be achieved at lower temperatures. By using only bio-based molecules, a fully bio-based thermoset with applicability in everyday life was obtained. [ABSTRACT FROM AUTHOR]

Ionic liquids have found their way into many applications where they show a high potential to replace traditional chemicals. But concerns over their ecological impacts (toxicity and biodegradability) and high cost have limited their use so far. The outcome of existing techno-economic and life-cycle assessments comparing ionic liquids with existing solvents has proven hard to interpret due to the many metrics used and trade-offs between them. For the first time, this paper couples the concept of monetization with detailed process simulation and life-cycle assessment to estimate the true cost of ionic liquids. A comparative case study on four solvents used in lignocellulosic biomass pretreatment is conducted: triethylammonium hydrogen sulfate [TEA][HSO4], 1-methylimidazolium hydrogen sulfate [HMIM][HSO4], acetone from fossil sources, and glycerol from renewable sources. The results show that the total monetized cost of production accounting for externalities can be more than double the direct costs estimated using conventional economic assessment methods. [TEA][HSO4] is found to have the lowest total cost, while glycerol presents the highest total cost. We expect this methodology to provide a starting point for future research and development in sustainable ionic liquids. [ABSTRACT FROM AUTHOR]

NdFeB permanent magnets are essential for modern day technology thanks to their excellent magnetic properties. Recycling of critical metals from sintered NdFeB permanent magnets has attracted a lot of attention over the last decade, whereas the recycling of (polymer or resin) bonded NdFeB magnets has been largely neglected. In this paper, an overview of the polymer or resin binders used in commercial bonded magnets is presented and different routes for the recycling of these magnets are explored. Three main types of polymers were found in commercial bonded NdFeB magnets: polyamides (PA6 and PA12), poly-p-phenylene sulfide (PPS) and epoxy. Both types of polyamide resins were easily dissolved by ionic liquids with coordinating anions (chloride, acetate or dialkylphosphate). Removal of the PPS resin was not possible by ionic liquid solvents, but only by using 1-chloronaphthalene and 1,3,5-triphenylbenzene at high temperatures. Although epoxy could be removed by several ionic liquids, reaction between the NdFeB powder and the ionic liquids was observed. A batch of PA6-bonded magnets was treated with an ionic liquid tributylethylphosphonium diethylphosphate, [P4442][Et2PO4], to selectively remove the polymeric portion. The PA-free magnet powder was found to retain >90% of its original magnetic properties. Two epoxy-bonded magnets produced with this recycled magnet powder showed magnetic properties that were close to those of commercial counterparts, proving the versatility of the process and that the materials loop could be successfully closed. [ABSTRACT FROM AUTHOR]

This paper reports a new concept for the biorefinery of lignocellulosic biomass where the derivatisation and fractionation of lignocellulose are accomplished at the same time. Methylation of sawdust of Larix kaempferi (Lamb.) Carriεave;re in dimethyl sulfoxide/tetrabutylammonium fluoride followed by fractionation provided three different polymeric derivative fractions: methylated cellulose, lignin, and hemicellulose. An aqueous solution of the methylated hemicellulose fraction was amphiphilic and possessed surface activity similar to that of industrially-produced methylcellulose. The azido-functionalised methylated cellulose and lignin fractions reacted with peracetyl propargyl β-cellobioside via Huisgen 1,3-dipolar cycloaddition followed by the removal of acetyl groups to yield a methylcellulose-block-cellobiose and methylated lignin-graft-cellobiose, respectively. An aqueous solution of diblock methylcellulose analogue, methylcellulose-block-cellobiose, formed thermoreversible supramolecular hydrogels near human body temperature. Methylated hemicellulose exhibited amphiphilic properties and acted as a surfactant. Methylated lignin-graft-cellobiose formed nanoparticles. Three major components in lignocellulosic biomass, cellulose, hemicellulose, and lignin, were successfully converted into three different functional materials. [ABSTRACT FROM AUTHOR]

Optically pure amino alcohols are widely used as essential building blocks of catalysts and auxiliaries in asymmetric synthesis, especially in pharmaceuticals. Catalytic hydrogenation has been regarded as the most effective route to produce chiral amino alcohols, but it is still unsatisfactory, which mainly manifests in the involvement of extra acids and bases, thus generating a large amount of inorganic salt byproducts, along with a relatively low yield. In this paper, we propose a novel approach that integrates catalytic hydrogenation and electrodialysis with bipolar membranes (EDBM) to produce pure chiral amino alcohols in a completely green way. EDBM tackles the sustainability issue by splitting the resulting salt of the hydrogenation into the corresponding acid and base (amino alcohol solutions), and the acid could be reused in the next batch directly and a closed loop forms. Here, as a model system to demonstrate the feasibility, a biorenewable chiral L -alanine solid and clean H2 gas are used as the feed stocks and finally converted into a pure L -alaninol product successfully, with no discharge of harmful substances. Furthermore, three typical mineral acids (H3PO4, H2SO4 and HCl) have been investigated systematically and achieved similar performances. The results of all tests and the cost analysis strongly suggest that this new approach is widely applicable, highly productive and sustainable. It demonstrates a true atomically economic route to produce chiral amino alcohols and entirely meets the requirements of green chemistry. [ABSTRACT FROM AUTHOR]

FDCA esters are highly relevant biobased alternatives for currently used benzene dicarboxylic acid esters. Despite all the developments on 2,5-FDCA applications, to the best of our knowledge thus far no toxicological data were available for 2,5-FDCA esters. In the present study we aimed to fill this gap, by using an in vitro reporter gene assay approach to compare the activity profile of commonly used phthalates to that of their furan-based counterparts. The assay selection was aimed at the detection of endocrine activity, since several phthalates are heavily scrutinised for their endocrine disrupting properties. However, to avoid missing other relevant toxicological endpoints, several assays able to detect various forms of cellular stress were also included in the panel. The results showed that the (ortho)benzene dicarboxylic acid esters were predominantly active on several of the endocrine assays. In comparison, six of the seven furan dicarboxylic acid based diesters tested here showed no activity in any of the 13 assays used. Only the isobutyl derivative DIBF showed moderate estrogenic activity on one assay, compared to much more pronounced activities on four assays for the ortho-phthalate analogue. Overall, the results presented in this paper are a strong indication that 2,5-FDCA based diesters in general are not only technically viable alternatives to phthalates, but also offer significant toxicological benefits, which supports a non-regrettable substitution. [ABSTRACT FROM AUTHOR]

Tough keratin fibers from chicken feathers have been produced continuously via controlled assembly of secondary protein structures. Though research on utilization of keratinous wastes began decades ago, very few regenerated products with high quality were developed due to damage to the primary structures during extraction and poor recovery of the secondary structures in the regenerated materials. Fibers have the highest quality requirements among the regenerated keratin products, including high toughness and resistance to repeated laundering. Our group developed regenerated keratin fibers on a lab scale previously. However, the regenerated keratin had poor spinnability with low recovery of secondary protein structures. As a result, keratin fibers could not be produced continuously, and their properties, especially the wet strength, were not acceptable. In this paper, high drawing ratios of keratin fibers on a continuous line have been achieved via stepwise oxidation and drawing technology. This technology resulted in controlled assembly of disulfide crosslinkages, optimum recovery of the secondary structures, satisfactory mechanical properties and scalable production of keratin fibers. Furthermore, the use of inexpensive chemicals makes the continuous keratin fiber production developed in this work affordable for scale-up. The technology developed for continuous production of tough keratin fibers has high potential for the development of high quality regenerated products from other cysteine-containing protein materials. [ABSTRACT FROM AUTHOR]

In this paper we study dry reforming of methane (DRM) in a gliding arc plasmatron (GAP) in the presence of N2 and O2. N2 is added to create a stable plasma at equal fractions of CO2 and CH4, and because emissions from industrial plants typically contain N2, while O2 is added to enhance the process. We test different gas mixing ratios to evaluate the conversion and energy cost. We obtain conversions between 31 and 52% for CO2 and between 55 and 99% for CH4, with total energy costs between 3.4 and 5.0 eV per molecule, depending on the gas mixture. This is very competitive when benchmarked with the literature. In addition, we present a chemical kinetics model to obtain deeper insight in the underlying plasma chemistry. This allows determination of the major reaction pathways to convert CO2 and CH4, in the presence of O2 and N2, into CO and H2. We show that N2 assists in the CO2 conversion, but part of the applied energy is also wasted in N2 excitation. Adding O2 enhances the CH4 conversion, and lowers the energy cost, while the CO2 conversion remains constant, and only slightly drops at the highest O2 fractions studied, when CH4 is fully oxidized into CO2. [ABSTRACT FROM AUTHOR]

This paper aims to evaluate the reduction in greenhouse gas emissions of rice and wheat and their supply chains by incorporating carbon capture, utilisation and storage into fertiliser production mainly from the ammonia process, which is a part of the fertiliser that produces most of the carbon dioxide. Greenhouse gas emissions of these grains without carbon capture, utilisation and storage are provided from the results of life cycle assessment in the literature. After that, carbon dioxide emission from fertiliser production is quantified. The alternative considered for utilisation is enhanced oil recovery and it is compared with the conventional way of oil production. The effects of carbon capture, utilisation, and storage on greenhouse gas reduction are presented in terms of the supply chains of rice and wheat to make people conscious about the use and optimisation of food. The reduction of greenhouse gas is around 6–7% in the rice supply chain e.g. rice milk, spoons of uncooked rice and 14–16% in the wheat supply chain e.g. pasta, one slice of bread. Although the alternative for carbon dioxide storage demonstrates marginally higher greenhouse gas reduction, enhanced oil recovery may offer an economic incentive from additional oil production that could reduce the cost of rice and wheat. [ABSTRACT FROM AUTHOR]

Cellulose, the most abundant polymer on Earth, and its composites have recently gained importance for the production of sustainable materials. These materials should be produced using green methods that avoid the utilization of toxic chemicals to ensure integrity for environmental sustainability. Ball milling, which gives a straightforward and (often) green synthetic access to materials, can be used to achieve this goal. Previously, it was shown that mechanochemical bond breakages in polymers generate mechanoradicals, which can be used to drive further reactions and to form polymer composites. In this study, we show that cellulose mechanoradicals generated during the ball milling of cellulose can reduce various metal ions to the corresponding metal nanoparticles (NPs) (Au, Ag, Pt, Pd, Co, and Cu), which are deposited and stabilized in the cellulose matrix. Using mechanoradicals to reduce the metal ions and form the cellulose composites, (1) the number of synthetic steps is reduced, and (2) the conventionally used, toxic reducing and stabilizing agents are avoided, which also prevents the contamination of the composites. The cellulose–metal nanoparticle composites can exhibit a wide range of properties that depend on the metal nanoparticle in the composite; e.g., Au–cellulose nanocomposites exhibit catalytic activity, and Ag–cellulose nanocomposites exhibit antibacterial properties. The ball-milling method also permits blend formation using synthetic polymers, which allows tuning the physical properties of the final material. Finally, the method shown here provides a quick access to versatile metal nanoparticle cellulose composites (and their blends), which may find applications, such as in paper-based diagnostics and catalysis. [ABSTRACT FROM AUTHOR]

In this paper, we propose a halogen-free process for the preparation of germanium micro-scale particles with a nano-structured surface morphology from germanium citrate, an easily accessible and environment-friendly precursor formed from germanium dioxide and citric acid in an aqueous medium. Electrodeposition of nanostructured Ge anodes on copper foil was performed via electrolysis of 1–5% germanium citrate solution in propylene glycol with addition of 5% acetic acid. Cyclic voltammetry data suggested that germanium citrate is an electrochemically inactive compound, but readily undergoes reduction by cathodic hydrogen released in the electrolysis. Such behaviour allows one to run the electrolysis under simple galvanostatic conditions without any need for controlling the potential. Furthermore, no diaphragm is required to separate the cathodic and anodic cell compartments. The electrodeposition produces black and compact films composed of ∼200 nm germanium particles, which, in turn, consist of nanoparticles no larger than 25 nm in size (SEM and TEM data). XRD and Raman spectroscopy data lead to the conclusion that germanium precipitates in the amorphous phase; however, with an increase in the power of the He–Ne laser (632.8 nm) during Raman spectra recording, it transforms into a nanocrystalline form. Testing germanium anodes in lithium-ion half-cells showed a specific capacity of ∼600 mA h g−1 at 1–2C current rates, which is comparable to the best results achieved for Ge anodes produced using more sophisticated and less environment-friendly techniques. [ABSTRACT FROM AUTHOR]

Natural deep eutectic solvents have emerged as alternative non-toxic, non-aqueous solvents for an increasing number of synthetic transformations. Remarkably, in some cases one (or more) components of the NaDES plays an active role in the reaction mechanism and directly participates as either a catalyst or a reagent in the reaction. In this paper, we tested several NaDESs in which one of the components is a carboxylic acid as a medium to perform the Nazarov cyclization of divinyl ketones to obtain cyclopentenones, a widespread motif in natural compounds. The reaction conditions were optimized and the scope was investigated on C-, O- and N-derived compounds. To assess the full sustainability of the proposed approach, the recyclability and scalability of the process were investigated, thus proving that multi-gram preparations are possible with complete recycling of the medium. [ABSTRACT FROM AUTHOR]

Mechanochemistry refers to a chemical reaction induced by mechanical energy involving solids. This method provides several advantages over solution-phase synthesis, such as minimizing the need for large volumes of solvents in chemical reactions and greener and more efficient synthetic solutions. In this paper we obtain, via mechanochemistry, a hybrid salt, named MEFAS, derived from two antimalarial molecules – mefloquine and artesunate. We demonstrate, using a simple experimental procedure, how the catalytic amount of liquid present during mechanochemical reactions is decisive to obtain MEFAS. Fourier-transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR) data indicate that liquid-assisted mechanochemical reactions are promising in the formation of the hybrid salt, which is formed via a hydrogen interaction of the carboxylate group of the artesunate molecule with the piperidine group of mefloquine. [ABSTRACT FROM AUTHOR]

Process mass intensity (PMI) is a key mass-based metric to evaluate the green credentials of an individual or sequence of reactions during process and chemical development. The increasing awareness to consider greenness as early as the initial discovery level, requires a set of parameters suitable to assess it at this stage of development, and guidelines to apply them correctly. This paper evaluates when and how PMI can be used in a correct manner. Different simulations for key reactions in the organic synthesis toolbox – i.e. amide bond formation and Mitsunobu reactions – illustrate that PMI can easily be misleading without due consideration of yield, concentration and molecular weight of reactants and product. A fair appraisal of the green potential of different methodologies therefore requires careful analysis of the examples and metrics data generated. [ABSTRACT FROM AUTHOR]

Iron-catalysed 1,2-acyl migration of tertiary α-azido ketones and 2-azido-1,3-dicarbonyl compounds provides a simple and atom-economical approach toward enamides and isoquinolones. This paper reports two catalyst systems for these transformations which employ iron(II) complexes [Fe(dpbz)]Br2 (dpbz = 1,2-bis(diphenylphosphino)benzene) and FeBr2/Et3N, respectively. [Fe(dpbz)]Br2 was found to be highly effective at converting 2-azido-2,3-dihydro-1H-inden-1-ones to isoquinolones. The reagent combination of FeBr2/Et3N, on the other hand, exhibited a broader catalytic scope, owing to the beneficial effect of Et3N. This latter catalyst system enables 2-azido-2-methyl-1,3-dicarbonyl compounds to be converted to the corresponding enamides under mild conditions in good yields. [ABSTRACT FROM AUTHOR]

We show that 5-(hydroxymethyl) furfural (HMF) and acetone can be selectively converted into a range of biomass-derived high molecular weight chemicals in high yield (>90%). HMF was condensed with acetone and purified to produce HMF-Acetone-HMF dimer (HAH). We then selectively synthesized various compounds from HAH by the sequential catalytic reaction pathway of hydrogenation, ring-opening, and hydrodeoxygenation. These synthesized HMF-derived chemicals were characterized by 1D and 2D NMR spectra and high resolution mass spectrometry (HRMS). The HMF-derived molecules described in this paper can be feedstocks for the polymer, pigment, and petroleum industries. [ABSTRACT FROM AUTHOR]

Polycarbonate (PC) is a transparent polymeric material which can replace shattering glass, but bisphenol-A, used for improving its properties, has controversial hazards. An alternative biomass-derived isosorbide (ISB)-based PC can be used owing to its complementary properties. To satisfy the two factors of sustainability and performance simultaneously, this paper proposes the in situ polymerization of ISB pre-dispersed with cellulose nanocrystals (CNCs), which directly produces PC nanocomposites, as a facile method for achieving record-high mechanical strength among all types of PCs and their nanocomposites. The proposed nanocomposite is more transparent, exhibits an ultimate tensile strength of 93 MPa and a 4.3-fold increased toughness of 40 MJ m−3, compared to a homo-polymer, and is better than post-blended nanocomposites due to the excellent dispersibility of 0.3 wt% nanofiller. Formidable improvements in in situ PC/CNC nanocomposites originate from the simultaneous contributions of covalent and physical interactions through polymeric grafting on the CNC surface and hydrogen bonding with a polar ISB moiety of PC, in advance, from the monomer dispersion, respectively, enhancing the interfacial interaction with the polymer matrix. This in situ approach opens new possibilities in the field of sustainable plastic industries. [ABSTRACT FROM AUTHOR]

In this paper, we propose a new approach for valorization of monosaccharides derived from biomass into value added chemicals in a green and economically efficient manner by forming eutectic medium exclusively between reactants. Eutectic mixtures are emerging as an advantageous alternative to ionic liquids and have already found broad applications in biomass treatment; however they are preferably used only as low vapor pressure solvents. Increasing interest in eutectic solvents originates from their flexibility to adjust their properties to different biorefinery needs by simple variation of the compositions of eutectic mixtures. In this work, we made a first attempt to use a low molecular weight component, ammonium formate, to significantly change the physical properties of the eutectic mixtures and simultaneously increase their chemical reactivity. Using this approach, we valorised simple monosaccharides by turning them into fructopyrazines with high yields in their eutectic mixtures with ammonium formate. The research revealed a high sensitivity of the product yields to the temperature of the reaction and composition of the eutectic medium, as well as an important role of formate anions in product stabilization. [ABSTRACT FROM AUTHOR]

For sustainable production and consumption, emerging green technologies need to be optimized towards a minimal environmental impact and a maximal economic impact. In an early stage of technology development, more flexibility is available to adapt the technology. Therefore, a prospective environmental and techno-economic assessment is required. The prospective assessment differs at the different stages of technology development, as also the data availability and accuracy evolves. This paper reviews the different prospective technological, economic and environmental assessment methods which have been used to assess the potential of new green chemical technologies. Based on the current best practices, an overarching framework is introduced to assess the technological, economic and environmental potential of an emerging green chemical technology at the different stages of technology development. [ABSTRACT FROM AUTHOR]

In this paper, a novel and efficient one-pot synthesis of 2,2,2-trifluoroethylphenanthridines (4) and benzochromenones (5) through three-component reactions of vinyl azides (1) with cyclic α-diazo carbonyl compounds (2) and Togni's reagent (3) is presented. In these cascade reactions, 3 acted not only as the source of a CF3 radical to react with 1 and 2 to afford 4, but also as the pool of o-iodobenzoic acid to couple with 2 to afford 5. To our knowledge, this is the first example in which 4 and 5 were obtained in a one-pot manner, and the byproduct of Togni's reagent, o-iodobenzoic acid, was trapped in situ by another substrate to give valuable products instead of being eliminated as a waste. [ABSTRACT FROM AUTHOR]

Quinaldic acids are important fine chemicals. Nowadays, industrial methods to synthesize quinaldic acids rely heavily on a three-step process established based on the Reissert reaction, which involves however the use of highly toxic potassium cyanide. In this paper, a novel cyclization of aniline with ethyl 4,4-diethoxycrotonate was realized, which offered ethyl quinaldate in good yield. Based on this reaction, an eco-efficient method to prepare quinaldic acids was developed, which involves the following three steps: (i) synthesis of ethyl 4,4-diethoxycrotonate through photooxidation of furfural and a consecutive ring-opening alcoholysis; (ii) cyclization of ethyl 4,4-diethoxycrotonate with aniline, and (iii) hydrolysis of the generated ethyl quinaldate. This new method not only avoids the use of toxic potassium cyanide but also meets many salient features of green chemistry, such as the use of bio-based feedstocks, environmentally benign metal-free conditions and good reaction yields. [ABSTRACT FROM AUTHOR]

A novel method is developed to reclaim carbon fibres from carbon fabric-reinforced cementitious composites. The method takes advantage of an electrically driven chemical reaction in the presence of an aqueous electrolyte solution and an electrical current. This paper presents an experimental programme to investigate the effects of the applied current density, the sodium chloride and nitric acid concentrations in the solution and the temperatures. Both tensile strengths and interfacial shear strengths of the reclaimed carbon fibres were evaluated. Microstructural analyses on the morphologies of the reclaimed carbon fibres were also performed. The proposed method is simple, environmentally friendly and efficient. This method has no size limits on the recycled composites, which indicates the suitability of this approach for large-scale industrial applications. The reclaimed carbon fibres are found to be intact and believed to have great commercial value since the recycling process did not damage their strengths or reduce their dimensions. [ABSTRACT FROM AUTHOR]

Most organic solvents cannot dissolve carbohydrates due to the lack of hydrogen bonding ability of the solvent. The components of deep eutectic solvents (DESs) are held together with strong hydrogen bonds, which are capable of forming favourable interactions with carbohydrates. In this paper, we study the solute–solvent interactions of glucose, sucrose, erythritol, cellobiose, starch and cellulose in five different choline chloride-based DESs. The hydrogen bond donors used were urea, oxalic acid, ethylene glycol, glycerol, and 1,5-pentanediol. Molecular weight of starch and cellulose was determined by size exclusion chromatography, and the degree of polymerisation was noticed to influence the solubility. The enthalpy of hydrogen bond formation of the DESs was quantified by differential scanning calorimetry, and found to correlate well with the solubilities of the mono and di-saccharides. No correlation was found between void size of DESs and carbohydrate solubility, whereas high viscosity of the DESs restricted the solubility. In general, carbohydrates showed good solubilities in the studied DESs, and some similarities were observed between aqueous solutions and ionic liquids. Ethaline showed the best performance as it had lowest viscosity, and no degradation of the carbohydrate occurred. The intermolecular interactions between glucose and Ethaline molecules were investigated by spectroscopic techniques, including 1H NMR and 2D {1H–1H}-NOESY and {1H–19F}-HOESY. Results showed that the hydrogen bond acceptor ability of the choline anion was mainly responsible for the dissolution of the carbohydrate. The solubility of cellulose in ionic liquids and DESs is discussed in terms of the thermodynamics of solvation, being concluded that the entropy change of solvation was the driving force for cellulose solubility in highly ordered ionic liquids. The lower order of DESs could not enable sufficient entropy gain of the solvent resulting lower solubilisation. [ABSTRACT FROM AUTHOR]

This work provides a critical review of the potential of integrating green methanol production processes in pulp mills. It identifies the current challenges, available synergies and future trends, whilst considering the inside perspective of current experts on implementing biorefinery processes and projects in this industry. The performed analysis shows that green methanol can be a key material in various decarbonization strategies, and pulp mills are natural frontrunners to establish production plants due to their suitability to implement biorefinery processes and the local existence of large flowrates of biogenic CO2. Three potentially integrable pathways were identified and discussed: (i) e-methanol from captured CO2 and green H2, (ii) biomethanol from the gasification of Kraft pulping byproducts and (iii) biomethanol from the purification of stripper off gases. However, several challenges and drawbacks must be tackled, such as insufficient low-cost renewable electricity, transmission grid issues, complex process implementation, difficult synergy seizing, low maturity of the technology start-to-end chain and unclear legislation, that ultimately result in excessive production costs and lack of stakeholder's confidence. The inability to address these challenges can lead to the failure or postponement of projects, consequently reducing the potential role that green methanol and hydrogen strategies can have towards full energy decarbonization. [ABSTRACT FROM AUTHOR]

Supramolecular assemblies of pentacenequinone derivative 4 act as reactors, reducing agents and shape directing agents for the preparation of PANI@Au:CuO nanocomposites (NCS). The as-prepared PANI@Au:CuO NCS serve as recyclable photocatalysts to construct 2-arylbenzimidazole derivatives under mild conditions through sequential amination, azidation and annulation reactions (visible light irradiation, room temperature and aerial conditions). The present protocol emphasizes the role of assemblies of the pentacenequinone derivative as visible light harvesting materials as well as oxidants in multiple C–N bond formation reactions. To our delight, the reaction also worked well under natural sunlight. The mechanistic studies supported the in situ generation of H2O2 during the reaction. Further, a portable paper based “dip catalyst” has been developed for carrying out sequential amination, azidation and annulation reactions. [ABSTRACT FROM AUTHOR]

The prolonged survival of microbes on surfaces in high-traffic/high-contact environments drives the need for a more consistent and passive form of surface sterilization, with the goal of minimizing pathogen transmission. Here, we developed self-disinfecting materials through the covalent attachment of a porphyrin-based photosensitizer (PS) to nanofibrillated cellulose (NFC) and paper (Pap), imparting antimicrobial activity to these renewable scaffolds via photodynamically generated singlet oxygen. The facile covalent attachment of the free-base 5-(4-aminophenyl)-10,15,20-tris-(4-N-methylpyridinium)porphyrin (A3B3+) and metallated [5-(4-aminophenyl)-10,15,20-tris-(4-N-methylpyridinium)porphyrinato]zinc(ii) (Zn-A3B3+) photosensitizers was accomplished by aqueous cyanuric chloride coupling, avoiding the use of organic solvents of previous coupling strategies, while preventing PS leaching that is an issue with non-covalent PS incorportation strategies. Materials characterization and the degree of photosensitizer loading were determined by FTIR, elemental and TGA analyses, and UV-Visible Diffuse Reflectance Spectroscopy (UV-Vis DRS). The antimicrobial potencies of the resultant PS-NFC and PS-Pap materials were evaluated against four strains of bacteria recognized by the World Health Organization as either critical or high priority pathogens: Gram-positive strains methicillin-resistant S. aureus (MRSA; ATCC-44) and vancomycin-resistant E. faecium (VRE; ATCC-2320), and Gram-negative strains multidrug-resistant A. baumannii (MDRAB; ATCC-1605) and NDM-1 positive K. pneumoniae (KP; ATCC-2146). Our results demonstrated broad photodynamic inactivation of all strains studied upon illumination (30 min; 65 ± 5 mW cm−2; 400–700 nm) by a minimum of 99.999%. Antiviral studies against two enveloped viruses, dengue-1 (DENV) and vesicular stomatitis virus (VSV), revealed complete inactivation by both materials. Taken together, the results demonstrate the potential for photoactive NFC as the basis for sustainable broad spectrum anti-infective materials. [ABSTRACT FROM AUTHOR]

Deep eutectic solvents (DESs) have been intensively investigated as promising “green” solvents for a range of industrial processes, although most research continues to be focused on binary DESs. This paper reports on a class of ternary DESs formed by choline chloride (ChCl), polyethylene glycol (PEG), and boric acid (BA) that may be viewed as a new system for extraction and oxidative desulfurization (ODS) of diesel fuel. Compared with organic acid-based DESs, ternary DESs offer advantages including low volatility, low toxicity, and high activity. After tuning the molar ratio of the three compositions, sulfur removal reached 99.2% in 2 h at 60 °C when the molar ratio of H2O2 to dibenzothiophene was 6. The binary DESs, ChCl/PEG and ChCl/BA, showed unsatisfactory extraction and oxidation efficiency. The reaction mechanism identified through experimental and theoretical methods showed that superoxide radical may be the main active oxygen species, and BA-based peroxides may also play an important role. The results of this study may expand the use of BA and supply a new class of DESs for ODS and other possible applications. [ABSTRACT FROM AUTHOR]

Four principal intra-particle phenomena occur in a highly concerted manner during the pyrolysis of lignocellulosic materials: heat transfer, mass transfer, chemical reactions, and phase changes. Achieving a holistic understanding of these processes has been challenged by their intricate coupling, high temperatures, and rapid rates at which they occur. Heat and mass transfer have been well studied at the single-particle level but their coupling with chemical reactions and phase change within single particle models remains problematic. Equally challenging is the multiscale coupling of reactor- and single particle-scale models. Too little attention has been given to phase change. Similarly, the presence of oligomeric compounds (constituting up to 20% of the oil) has not been fully accounted for in chemical reaction schemes and physical models developed for pyrolysis. Recent studies have shown that a multiscale approach is key to predictive modelling across a variety of reactor systems. Historical and recent developments are outlined in this pyrolysis review paper regarding these four intra-particle phenomena, as well as modelling efforts to capture their effect on product yields and composition. It is critical for the design of future biomass pyrolysis systems to appropriately account for all four intra-particle phenomena and their inter-connectivities in order to predict, achieve, and maintain optimal operation. [ABSTRACT FROM AUTHOR]

Epoxidized vegetable oils (EVOs) are versatile building blocks for lubricants, plasticizers, polyvinyl chloride (PVC) stabilizers, and surface coating formulations. In this paper, a catalytic protocol for the efficient epoxidation of vegetable oils is presented that is based on a combination of a manganese catalyst, H2O2 as an oxidant, and acetic acid as an additive. This protocol relies on the use of a homogeneous catalyst based on the non-noble metal manganese in combination with a racemic mixture of the N,N′-bis(2-picolyl)-2,2′-bispyrrolidine ligand (rac-BPBP). The optimized reaction conditions entail only 0.03 mol% of the manganese catalyst with respect to the number of double bonds (ca. 0.1 wt% with respect to the oil) and ambient temperature. This epoxidation protocol is highly efficient, since it allows most of the investigated vegetable oils, including cheap waste cooking oil, to be fully epoxidized to EVOs in more than 90% yield with excellent epoxide selectivities (＞90%) within 2 h of reaction time. In addition, the protocol takes place in a biphasic reaction medium constituted by the vegetable oil itself and an aqueous acetic acid phase, from which the epoxidized product can be easily separated via simple extraction. In terms of efficiency and reaction conditions, the current epoxidation protocol outperforms previously reported catalytic protocols for plant oil epoxidation, representing a promising alternative method for EVO production. [ABSTRACT FROM AUTHOR]

Screening all existing and new commercial chemicals using computational models is a promising alternative to economically and ethically unviable animal tests. High throughput screening (HTS) assays and quantitative structure–activity relationships (QSARs) developed to assess chemical exposure, hazard and risk are a testament to the shift toward cost-effective strategies to protect human and environmental health. While existing computational tools can be used to screen chemicals for toxic endpoints, their utility in informing design of safer chemicals is limited. Rational design of chemicals with minimal biological activity and optimal functional efficacy is the foundational principle of green chemistry; yet, it is also the least-developed field of this discipline. This paper outlines development of a computational framework for designing commercial chemicals, while considering both their biological activity and intended function. The approach resembles computational drug discovery, applied to systematically design out target-specific toxicities utilizing prior knowledge of molecular initiating events (MIE) in adverse outcomes pathways (AOP). Statistical free energy perturbation calculations are employed to demonstrate this approach for organophosphate flame retardants, a prominent class of chemicals of concern. This framework promises a strategy for safer chemical design that allows the practitioner to systematically weigh chemical drivers of toxicity, metabolism and functionality to determine trade-offs and optimal solutions to existing toxic chemicals. Complementing predictive toxicology approaches and design guidelines, this framework could advance the practice of developing safer substitutes, which is presently considered unfavourable due to high costs, prolonged development periods, and the potential of introducing a new mode of toxicity. [ABSTRACT FROM AUTHOR]

A novel method of cleaning waste lignin biomass by means of selective biodegradation of cellulose and hemicellulose is investigated. This method uses Pseudomonas fluorescens (P. fluorescens), a non-pathogenic bacterium capable of producing cellulolytic enzymes, cleaving polymeric carbohydrates into free sugars and utilizing them as their carbon source. The growth of P. fluorescens on lignin biomass was confirmed by increasing cell count with time and visualized by scanning electron microscopy (SEM). Depletion of free sugars in the growth medium was measured by Technical Association of the Pulp and Paper Industry (TAPPI) methods and by time-of-flight secondary ion mass spectrometry (ToF SIMS), which showed a significant decrease in the carbohydrate content and an increase in the lignin fraction after P. fluorescens biodegradation. The molar mass distribution of lignin before and after the biodegradation of carbohydrate impurities showed no indication of lignin depolymerization. Our results strongly support the biodegradation of carbohydrate impurities from waste lignin by P. fluorescens as an effective, green and eco-friendly process. [ABSTRACT FROM AUTHOR]