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Commercial (protiated) samples of the green and biodegradable bioester 2-ethylhexyl laurate (2-EHL) were mixed with D-2-EHL synthesized by hydrothermal deuteration, with the mixtures demonstrating bulk structuring in small-angle neutron scattering measurements. Analysis in a polymer scattering framework yielded a radius of gyration (R (g)) of 6.5 angstrom and a Kuhn length (alternatively described as the persistence length or average segment length) of 11.2 angstrom. Samples of 2-EHL dispersed in acetonitrile formed self-assembled structures exceeding the molecular dimensions of the 2-EHL, with a mean aggregation number (N-agg) of 3.5 +/- 0.2 molecules across the tested concentrations. We therefore present structural evidence that this ester can function as a nonionic (co)-surfactant. The available surfactant-like conformations appear to enable performance beyond the low calculated hydrophilic-lipophilic balance value of 2.9. Overall, our data offer an explanation for 2-EHL's interfacial adsorption properties via self-assembly, resulting in strong emolliency and lubricity for this sustainable ester-based bio-oil.

Polyethylene terephthalate (PET) is one of the most common plastics and can be cascaded mechanically during its life cycle. However, recycling affects the mechanical properties of the material, and the virgin material is constantly in demand. If a worn material could be depolymerized to its chemical building blocks, then a virgin polymer could be generated from old fibers. In this work, we have developed a benign organo-catalytic depolymerization of PET to yield dimethyl terephthalate (DMT) and ethylene glycol (EG) without the need for purification of generated monomers. By recirculating the solvent and organo-catalyst, a solvent/substrate ratio of 3:1 was achieved. The depolymerization was successfully applied to other polyesters, polycarbonates, and polycotton. The cotton isolated from the polycotton depolymerization was successfully processed into viscose fibers with a tenacity in the range of nonwaste cotton-derived viscose filaments. The global warming potential (GWP) of PET depolymerization was evaluated by using life cycle assessment (LCA). The GWP of 1 kg PET recycling is 2.206 kg CO2 equivalent, but the process produces DMT, EG, and heat, thereby avoiding the emissions equivalent to 4.075 kg CO2 equivalent from the DMT, EG, and steam-energy production through conventional pathways. Thus, the net result potentially avoids the emission of 1.88 kg of CO2 equivalent. The impact of this process is lower than that of waste PET incineration and conventional PET recycling technologies.

Reactive amine compounds are critical for a vast array of useful chemicals in society, yet a limited number of them are derived from renewable resources. This study developed an efficient route to obtain aminated building blocks from phenolic resources derived from nature, such as lignin and tannic acid, for enhancing their utility in applications such as epoxy resins, nylons, polyurethanes, and other polymeric materials. The reaction utilized a carbon storage compound, 2-oxazolidinone as a solvent and as a reagent circumventing the need of hazardous chemistry of conventional amination routes such as those involving formaldehyde. Both free acids and hindered phenolics were readily converted into aminoethyl derivatives resulting in aromatics with primary amine functionality. The aminated compounds, with the potential for enhanced reactivity, can pave the way toward more advanced renewable building blocks.

Photoluminescent carbon nanoparticles (CNPs), such as carbon dots (CDs), have attracted much attention owing to a unique set of properties, like high and tunable fluorescence. In this way, the use of carbon-rich lignin has been demonstrated to be a sustainable approach to producing a broad range of photoluminescent CNPs. However, the valorization of this complex polyphenol is limited when it comes to green and efficient ways of conversion. In addition, the existing solvothermal approaches using lignin often result in CDs with low photoluminescence, while flammable and/or toxic solvents are employed. Here, we depolymerized technical lignins, i.e. kraft and soda, through electroreductive cleavage in two different sustainable media: deep eutectic solvent and levulinic acid. After depolymerization, lignin-derived monomers were generated, with a predominance of aryl ether and phenolic groups, which were further combined with 1,2-Phenylenediamine to produce N-doped CNPs in a solvent-free approach. Photoluminescent CNPs with varied sizes were generated (5–50 nm), which presented a wide photoluminescence emission, from blue to red, depending on solvent polarity. These results demonstrate a feasible and sustainable route for the solvent-free synthesis of photoluminescent CNPs using lignin-derived monomers as carbon source, which may find applications in a wide range of fields.

The agro-sector generates organic waste of various kinds, which potentially could be used to prepare functional materials, lessen environmental problems, and enhance circularity. In this context, the hypothesis that was put forward in this work is that prickly pear seed waste from the Tunisian agro-food industry could be used to prepare activated carbons. The prickly pear seed waste was first hydrothermally carbonized and the resulting hydrochar was activated in CO2 at 800 °C. The yield of the hydrothermal carbonization process is of importance, and it was the highest at intermediate dwell times and temperatures, which was ascribed to the re-precipitation of hydrochar particles on the heat-treated biomass. The hydrochars and activated carbons were characterized with scanning electron microscopy, thermogravimetry, Raman spectroscopy, and N2 and CO2 adsorption/desorption analyses. The activated carbons had micro- (<2 nm) and mesopores (2–50 nm), and specific surface areas and total pore volumes of about 400 m2 −1 and 0.21 cm3 g−1. The study showed that the prickly pear seed waste could be effectively transformed into both hydrochars and activated carbons and that is advisable to optimize the hydrothermal process for the mass yield. A life cycle analysis was performed to assess the environmental impact of the production of typical activated carbons using the approach of this study. Further studies could be focused on enhancing the properties of the activated carbons by further optimization of the activation process.

The current biorefineries are focused on the comprehensive fractionation of biomass components into separate lignin and carbohydrate fractions for the production of materials, platform chemicals and biofuel. However, it has become obvious that the combination of lignin and carbohydrates can have significant technical, environmental, and economic benefits as opposed to their separate use. Herein, we developed a green, simple, and flexible biorefinery concept for the integrated utilization of all major biomass components for high-value applications with the focus on functional lignin–carbohydrate hybrids (LCHs). The established process consisted of a modified hydrothermal treatment (HTT) of birch wood followed by solvent extraction of the resulting solids and is therefore named AquaSolv Omni (AqSO) biorefinery. The AqSO biorefinery produces three major streams: hydrolysate (hemicellulose-derived products), solvent-extracted lignin–carbohydrate complexes (LCCs) and cellulose-rich fibers. Specific process conditions were found to facilitate the production of LCCs of different types in high yields as a new valuable and industrially realistic process stream. The effect of the process severity and liquid to solid (L/S) ratio on the yields and compositions of the produced fractions as well as on the structure and properties of the extracted LCCs was investigated using state of the art NMR spectroscopy and molar mass distribution analysis among other methods. The high flexibility of the process allows for engineering of the resulting products in a wide range of chemical compositions, structures and physicochemical properties and therefore gives a good opportunity to optimize the products for specific high-value applications. The process can be easily combined with other biorefinery operations (e.g., enzymatic hydrolysis, pulping, bleaching) to be incorporated into existing value chains or create new ones and thus is suitable for different biorefinery scenarios. First example

From manufacturing to disposal, the textile industry faces multiple challenges to achieve sustainability and reduce its environmental impact. This work investigates the properties and composition of cellulose nanocrystals (CNCs) extracted from clothing waste made of cotton fibers. We isolated CNCs from cotton, polyester/cotton, and acrylic/cotton waste fabrics through acid hydrolysis with sulfuric acid. A yield of 51-62 wt S4, ( co tt on basis) was obtained, and nearly all the polyester and acrylic libers contained in the initial fabrics were recovered in a convenient shape that could allow easier recycling. CNCs extracted from the selected fabrics showed high purity, similar structural, physical, and chemical characteristics, and their properties were comparable to those extracted from virgin sources, although their surface chemistry and elemental composition slightly differed. The chemical components in the waste fabrics and the extracted CNCs were evaluated through a nontarget chromatographic-mass spectrometric screening strategy. Both the recycled textiles and the CNCs contained hundreds of compounds common in postconsumer textiles, including some with health and environmental concerns. However, our initial findings show that their concentrations in the CNCs are negligible. Our results provide insights into the challenges associated with the use of cotton waste textiles for the extraction of cellulose nanoparticles, and into the potential applications of the extracted nanomaterials.

Direct hydroxylation via the functionalization of tertiary benzylic C(sp(3))-H bonds is of great significance for obtaining tertiary alcohols, which find wide applications in pharmaceuticals as well as in fine chemical industries. However, current synthetic procedures use toxic reagents, and therefore, the development of a sustainable strategy for the synthesis of tertiary benzylic alcohols is highly desirable. To solve this problem, herein, we report a metal-free heterogeneous photocatalyst to synthesize the hydroxylated products using oxygen as the key reagent. Various benzylic substrates were employed into our mild reaction conditions to afford the desirable products in good to excellent yields. More importantly, the gram-scale reaction was achieved via harvesting direct solar energy and exhibited high quantity of the product. The high stability of the catalyst was proved via recycling the catalyst and spectroscopic analyses. Finally, a possible mechanism was proposed based on electron paramagnetic resonance and other experimental evidence.

Sonochemical synthesis of nano-sized SrTiO3 carried out at close to room temperature, in ionic liquids (ILs) allows the tuning of particle size and particle morphology, that is, tracht and habitus, as well as particle aggregation via the choice of the ionic liquids (ILs) as the reaction medium. The nanoparticles demonstrate high performance for photocatalytic water splitting and photodecomposition of organic material. To this end bis(trifluoromethanesulfonyl)amide ([Tf2N](-))-based ILs with cations of different properties with respect to specific interactions with the target material are investigated. Isolated, 15 +/- 1 nm sized nano-spheres of SrTiO3 are observed to form in [C(3)mimOH][Tf2N] ([C(3)mimOH](+) = 1-(3-hydroxypropyl)-3-methylimidazolium). Aggregation of small sized nanoparticles are observed to around 250 +/- 100 nm large cube-like formations in [C(4)mim][Tf2N] ([C(4)mim](+) = 1-butyl-3-methylimidazolium), raspberry-like in [C4Py][Tf2N] ([C4Py](+) butylpyridinium), and ball-like in [P-66614][Tf2N] ([P-66614](+) tetradecyltrihexyl phosphonium). Importantly, the different materials show different performance as photocatalysts. SrTiO3 prepared in [C(4)mim][Tf2N] shows the highest photocatalytic activity for H-2 evolution (1115.4 mu mol h(-1)) when using 0.025 wt% Rh as the co-catalyst, whereas the material prepared in [C(3)mimOH][Tf2N] shows the highest activity for the photocatalytic degradation of methylene blue (88%) under UV irradiation. The different photocatalytic activities can be correlated with the different crystal surface facets expressed in the respective nanosized SrTiO3 material, {110} for material obtained from [C(4)mim][Tf2N], and {100} for material from [C(3)mimOH][Tf2N]. First-principles density functional theory (DFT) calculations are used to support the experimental findings.

Wood-foam hierarchical composites were produced via the shear-forced infiltration of shear-thinning nanocellulose-based foams or gels into the tracheids of Picea abies. Shear processing viscoelastic and shear-thinning aqueous foams composed of cellulose nanocrystals, methylcellulose, and tannic acid (total solids content: 2 wt %) resulted in foam-filled wood composites containing 15-20 wt % foam, with open foam structures and compression strengths similar to those of unmodified P. abies. An amino-functionalized nanocellulose-containing foam confined in wood reversibly adsorbed CO2, retaining 15% of its theoretical uptake capacity over 50 cycles in the thermogravimetric analyzer, and a citronellol-loaded foam released this mosquito-repellent compound over four days, as evaluated using solid-phase microextraction. Shear-forced infiltration of functional foams into wood is an operationally simple route to hierarchically porous composites based on renewable materials.

The achievement of frictionless systems, known as superlubricity, has become of great importance concerning energy saving and emission reduction. In parallel, the drive toward sustainability and environmental aspects has led to intense advances in the research and development of biobased materials. From the standpoint of Green Chemistry principles, this review presents a critical overview of the latest findings and future perspectives on the application of biobased materials aiming at superlubricant pursuits. The progress in the use of biomacromolecules, such as chitosan, cellulose, and lignin, as additives to lubricants or coating materials, are addressed, as well as the advances on sustainable coatings based on diamond-like carbon (DLC). Deeper investigations on the development of non-hazardous processes dedicated to the tribological properties of DLC, such as electrochemical synthesis using environment-friendly solvents to generate molecular precursors, widen the perspectives to achieve sustainable materials. Besides, the exploration of the tribochemical interactions between the DLC surface and lubricants containing biobased materials arises as a promising strategy to achieve green superlubricity as a viable and scalable process, through different pathways: by hydrogen bonds between lubricant and additives, via surface passivation of the functional groups present in these biomacromolecules or by biomimicking natural joints.

A series of asymmetric and symmetric 1,3-dialkyltriazolium iodides were studied with hindsight to their application as electrolytes and redox mediators in dye-sensitized solar cells (DSSCs). Compounds with an alkyl chain length from C4 to C10 present the characteristics of ionic liquids (ILs), whilst those with longer chains exhibit liquid crystallinity. All compounds show an appreciable chemical and thermal stability with decomposition temperatures around 185–195 °C. Testing these compounds as electrolytes and redox mediators in DSSCs reveals significant changes in the properties of the electrolyte upon addition of the redox couple. Addition of iodine generally leads to a depression of the melting point and an enhancement of conductivity. These changes in the electrolyte, which are significant, have so far been largely overlooked in DSSC optimization. Furthermore, in comparison to frequently employed imidazolium iodides, 1-alkyl-3-methyltriazolium iodides show both an improved superior efficiency and an extended cell lifetime. This is attributed to the fact that, unlike the imidazolium salts, the triazolium counterparts are not hygroscopic. The nonhygroscopic nature of the salts also renders device fabrication easier. In addition, electrode passivation, which is commonly observed with imidazolium iodides, could not be noticed for the triazolium analogues, making these materials overall extremely attractive.

A “waste-valorization” approach was developed to transform recalcitrant hydrolysis lignin (HL) from second-generation bioethanol production into multifunctional bio-based products. The hydrolysis lignin (HL) was extracted with aqueous acetone, yielding two fractions enriched in lignin and cellulose, respectively. The soluble hydrolysis lignin (SHL) was converted into anionic and cationic colloidal lignin particles (CLPs and c-CLPs). The insoluble cellulose-rich fraction was transformed into lignocellulosic nanofibrils that were further combined with CLPs or c-CLPs to obtain nanocomposite films with tailored mechanical properties, oxygen permeability and antioxidant properties. To enable prospective applications of lignin in nanocomposite films and beyond, CLPs and c-CLPs were also produced from a soda lignin (SL) and the influence of the lignin type on the particle size and ecotoxicity was evaluated. Finally, the carbon footprint of the entire process from hydrolysis lignin to films was assessed and an integration to industrial scale was considered to reduce the energy consumption. While most previous work utilizes purified lignin and pristine and often purified cellulose fibers to produce nanomaterials, this work provides a proof of concept for utilizing the recalcitrant lignin-rich side stream of the bioethanol process as raw material for functional nanomaterials and renewable composites.

Weak interfacial binding of lignin within synthetic polymer composites results in unsatisfactory mechanical properties that limit their application prospects. In the present work, polystyrene (PS) and poly(butyl methacrylate) (PBMA) nanocomposites containing lignin nanoparticles (LNPs) are produced by simple melting of polymeric latex dispersions obtained from free radical polymerization of oil-in-water Pickering emulsions stabilized by hybrid LNPs coated with chitosan and glucose oxidase. Owing to the formation of viscous polymer melts, the hybrid LNPs ended up uniformly dispersed within the polymeric matrices, which gave the polymeric nanocomposites markedly improved tensile strength without sacrificing their elasticity in comparison to pure PS and PBMA. Consequently, the composites reinforced with 15 wt% of the hybrid particles showed improvement in toughness by a factor of 3.5 and 15 compared to those of the corresponding pristine PS and PBMA. In addition, the presence of the hybrid particles conferred the nanocomposites with commendable UV-blocking and antioxidant properties which are relevant for protective packaging and coating applications. Overall, our results show a new and green route with excellent material economy (overall mass yield up to 91%) to obtain strong and transparent polymeric nanocomposites reinforced with up to 30 wt% of LNPs, which is expected to attract renewed interest in lignin-polymer composites for a broad range of applications.

Zinc sulfide (ZnS) and cadmium sulfide (CdS) nanoparticles were synthesized in different ionic liquids (IL) with microwave irradiation. Particle characterization by means of powder X-ray diffraction (PXRD), scanning electron microscopy (SEM) and optical spectroscopy (UV-vis absorption and photoluminescence) showed a strong dependence of the particle size depending on the IL employed. Whilst all ILs yielded particles in the nanometer regime and showed in their optical properties quantum confinement, particularly small particles were obtained from choline-base ILs pointing to the strong influence of this IL cation in blocking the particle growth. Here, quantum dots of 1.5–3 nm size were yielded for both, ZnS and CdS.

In modern chemical engineering processes, the involvement of solid/fluid interface is the most important component of process intensification techniques, such as confined membrane separation and catalysis. In the review, we summarized the research progress of the latest theoretical and experimental works to elucidate the contribution of interface to the fluid properties and structures at nano- and micro-scale. We mainly focused on water, alcohol aqueous solution, and ionic liquids, because they are classical systems in interfacial science and/or widely involved in the industrialization process. Surface-induced fluids were observed in all reviewed systems and played a critical role in physicochemical properties and structures of outside fluid. It can even be regarded as a new interface, when the adsorption layer has a strong interaction with the solid surface. Finally, we proposed a perspective on scientific challenges in the modern chemical engineering processes and outlined future prospects.

Tuning the local environment of nanomaterial-based catalysts has emerged as an effective approach to optimize their oxygen evolution reaction (OER) performance, yet the controlled electronic modulation around surface active sites remains a great challenge. Herein, directed electronic modulation of NiO nanoparticles was achieved by simple surface molecular modification with small organic molecules. By adjusting the electronic properties of modifying molecules, the local electronic structure was rationally tailored and a close electronic structure-activity relationship was discovered: the increasing electron-withdrawing modification readily decreased the electron density around surface Ni sites, accelerating the reaction kinetics and improving OER activity, and vice versa. Detailed investigation by operando Raman spectroelectrochemistry revealed that the electron-withdrawing modification facilitates the charge-transfer kinetics, stimulates the catalyst reconstruction, and promotes abundant high-valent gamma-NiOOH reactive species generation. The NiO-C(6)F(5)catalyst, with the optimized electronic environment, exhibited superior performance towards water oxidation. This work provides a well-designed and effective approach for heterogeneous catalyst fabrication under the molecular level.

In order to meet climate goals, both CO2 capture and storage (CCS) and CO2 capture and utilization (CCU) have been identified as increasingly important technologies for mitigating CO2 emissions that are difficult to avoid. In this work, the CO2 utilization, or more specifically, the CO2 conversion to fuels and urea, considering the large demand for CO2, as well as the CO2 mineralization are surveyed and reviewed. The content of this review includes technologies - all the way from the laboratory studies to the industrial applications - their current status, and future potential. CCS is included for a comparison concerning the costs. Also, aspects as the CO2 impurities and the effect of it as well as various requirements concerning the CO2 impurity are included. Many recent studies show that CCU, especially CO2 conversion to fuels, will play an essential role in mitigating CO2 emissions, while developed methods and technologies are not yet mature. More research work needs to be conducted to improve the process efficiency via developing catalysts and reducing the cost of producing H-2 that is used as a reactant for fuel synthesis. Moreover, current literature also shows that impurities will affect the process of both CCS and CCU, while the work of studying their influence, especially on CCU, is still scarce. The cost of CCS has been estimated combined with impurities, while studies on cost estimation for CCU are still limited, and the cost, in general, is relatively high with the currently available technologies.

Lignin is one the most fascinating natural polymers due to its complex aromatic‐aliphatic structure. Phenolic hydroxyl and carboxyl groups along with other functional groups provide technical lignins with reactivity and amphiphilic character. Many different lignins have been used as functional agents to facilitate the synthesis and stabilization of inorganic materials. Herein, the use of lignin in the synthesis and chemistry of inorganic materials in selected applications with relevance to sustainable energy and environmental fields is reviewed. In essence, the combination of lignin and inorganic materials creates an interface between soft and hard materials. In many cases it is either this interface or the external lignin surface that provides functionality to the hybrid and composite materials. This Minireview closes with an overview on future directions for this research field that bridges inorganic and lignin materials for a more sustainable future.

Introduced in the literature in 1913 by Bergius, who at the time was studying biomass coalification, hydrothermal carbonisation, as many other technologies based on renewables, was forgotten during the industrial revolution. It was rediscovered back in 2005, on the one hand, to follow the trend set by Bergius of biomass to coal conversion for decentralised energy generation, and on the other hand as a novel green method to prepare advanced carbon materials and chemicals from biomass in water, at mild temperature, for energy storage and conversion and environmental protection. In this review, we will present an overview on the latest trends in hydrothermal carbonisation including biomass to bioenergy conversion, upgrading of hydrothermal carbons to fuels over heterogeneous catalysts, advanced carbon materials and their applications in batteries, electrocatalysis and heterogeneous catalysis and finally an analysis of the chemicals in the liquid phase as well as a new family of fluorescent nanomaterials formed at the interface between the liquid and solid phases, known as hydrothermal carbon nanodots.

The effect of two process water (PW) recirculation strategies after hydrothermal carbonization (HTC) of brewers spent grains (BSG) is evaluated with the focus on the hydrochar characteristics. The HTC process has been carried out under different operating conditions, which are residence time between 2 and 4 h and temperature in the range of 200-220 degrees C. The composition of the hydrochars reveals that operating conditions have a more significant effect than PW recirculation. The composition of the liquid produced by HTC with PW recirculation is essentially controlled by the operating temperature, for instance, the total organic carbon (TOC) in the PW changes in the narrow range of 200-220 degrees C. A detailed analysis of PW also has been done. The main components of the liquid phase are lactic, formic, acetic, levulinic, and propionic acid as well as 5-hydroxymethylfurfural, that affect the surface structure of the hydrochars.

There is an increased interest in renewable carbon as a source of materials, where lignin is expected to play a prominent role. This stems, partially, from new regulations aiming to achieve a cleaner and safer environment. Lignin, as a polyaromatic plant-derived biomolecule, is not only abundant but widely accessible in industrial streams. Due to recent developments in production scalability as well as promising application prospects, nanoscaled lignin particles have recently generated interest in the research and industrial communities. This review describes the main routes to prepare spherical lignin particles, highlighting aspects associated to their shape and topology as well as performance. We discuss the use of spherical lignin particles as dispersants and in the formulation of coatings, adhesives and composites, focusing on the advantages of the spherical shape and nanoscaled size. The state of the particles is furthermore compared in terms of their applicability in dry and wet forms. Finally, we discuss the sustainability, stability and degradation of lignin particles, which are issues that are critically important for any prospective use.

Virus contamination of water is a threat to human health in many countries. Current solutions for inactivation of viruses mainly rely on environmentally burdensome chemical oxidation or energy-intensive ultraviolet irradiation, which may create toxic secondary products. Here, we show that renewable plant biomass-sourced colloidal lignin particles (CLPs) can be used as agglomeration agents to facilitate removal of viruses from water. We used dynamic light scattering (DLS), electrophoretic mobility shift assay (EMSA), atomic force microscopy and transmission electron microscopy (AFM, TEM), and UV spectrophotometry to quantify and visualize adherence of cowpea chlorotic mottle viruses (CCMVs) on CLPs. Our results show that CCMVs form agglomerated complexes with CLPs that, unlike pristine virus particles, can be easily removed from water either by filtration or centrifugation. Additionally, cationic particles formed by adsorption of quaternary amine-modified softwood kraft lignin on the CLPs were also evaluated to improve the binding interactions with these anionic viruses. We foresee that due to their moderate production cost, and high availability of lignin as a side-stream from biorefineries, CLPs could be an alternative water pretreatment material in a large variety of systems such as filters, packed columns, or flocculants.

Lignin is a phenolic polymer accumulatig in the cell walls of specific plant cell types to confer unique properties such as hydrophobicity, mechanical strengthening, and resistance to degradation. Different cell types accumulate lignin with specific concentration and composition to support their specific roles in the different plant tissues. Yet the genetic mechanisms controlling lignin quantity and composition differently between the different lignified cell types and tissues still remain poorly understood. To investigate this tissue-specific genetic regulation, we validated both the target molecular structures as well as the linear semi-quantitative capacity of Raman microspectroscopy to characterize the total lignin amount, S/G ratio, and coniferyl alcohol content in situ directly in plant biopsies. Using the optimized method on stems of multiple lignin biosynthesis loss-of-function mutants revealed that the genetic regulation of lignin is tissue specific, with distinct genes establishing nonredundant check-points to trigger specific compensatory adjustments affecting either lignin composition and/or cell wall polymer concentrations.

The tunicate species Ciona intestinalis is a fast-growing marine invertebrate animal that contains cellulose in its outer part-the tunic. The high crystallinity and microfibril aspect ratio of tunicate cellulose make it an excellent starting material for the isolation of nanocellulose. In the present work, tunic from C. intestinalis was subjected to organosolv pretreatment followed by bleaching and acid-hydrolysis steps for the isolation of nanocrystals. Applying an intermediate enzymatic treatment step with a lytic polysaccharide monooxygenase (LPMO) from the thermophilic fungus Thermothelomyces thermophila was proved to facilitate the isolation of nanocellulose and to improve the overall process yield, even when the bleaching step was omitted. LPMOs are able to oxidatively cleave the glycosidic bonds of a polysaccharide substrate, either at the C1 and/or C4 position, with the former leading to introduction of carboxylate moieties. X-ray photoelectron spectroscopy analysis showed a significant increase in the atomic percentage of the C=O/O-C-O and O-C=O bonds upon the addition of LPMO, while the obtained nanocrystals exhibited higher thermal stability compared to the untreated ones. Moreover, an enzymatic post-treatment with LPMOs was performed to additionally functionalize the cellulose nanocrystals. Our results demonstrate that LPMOs are promising candidates for the enzymatic modification of cellulose fibers, including the preparation of oxidized-nanocellulose, and offer great perspectives for the production of novel biobased nanomaterials.

Capture and conversion of CO2 are of great importance for environment-friendly and sustainable development of human society. Poly(ionic liquid)s (PILs) combine some unique properties of ILs with those of polymers and are versatile materials for CO2 utilization. In this contribution, we briefly outline innovative PILs emerged over the past few years, such as polytriazoliums, deep eutectic monomer-based PILs, and polyurethane PILs. Additionally, we discuss their advantages and challenges as materials for carbon capture and storage and the fixation of CO2 into useful materials.

Amine-modified adsorbents are being researched for their potential to capture CO2 from various gas mixtures, and we review how IR spectroscopy has been used to study the associated CO2-amine chemistry. It has been used to reveal that CO2 chemisorbs as ammonium-carbamate ion pairs especially when the amine density is high. Carbamic acid and related other moieties tend to form in parallel to the ion pairs when the amine density is low. The amines have been shown to degrade on cyclic heat treatment. To further study the formation of bicarbonates on reactive adsorption of CO2 and H2O, degradation of the organics, and the use of other supports than silica are suggested.

The highly active ruthenium-based water oxidation catalyst [Ru-X(mcbp)(OHn)(py)(2)] [mcbp(2-)=2,6-bis(1-methyl-4-(carboxylate)benzimidazol-2-yl)pyridine; n=2, 1, and 0 for X=II, III, and IV, respectively], can be generated in a mixture of Ru-III and Ru-IV states from either [Ru-II(mcbp)(py)(2)] or [Ru-III(Hmcbp)(py)(2)](2+) precursors. The precursor complexes are isolated and characterized by single-crystal X-ray analysis, NMR, UV/Vis, EPR, and FTIR spectroscopy, ESI-HRMS, and elemental analysis, and their redox properties are studied in detail by electrochemical and spectroscopic methods. Unlike the parent catalyst [Ru(tda) (py)(2)] (tda(2-)=[2,2:6,2-terpyridine]-6,6-dicarboxylate), for which full transformation into the catalytically active species [Ru-IV(tda)(O)(py)(2)] could not be carried out, stoichiometric generation of the catalytically active Ru-aqua complex [Ru-X(mcbp)(OHn)(py)(2)] from the Ru-II precursor was achieved under mild conditions (pH7.0) and short reaction times. The redox properties of the catalyst were studied and its activity for electrocatalytic water oxidation was evaluated, reaching a maximum turnover frequency (TOFmax) of around 40000s(-1) at pH9.0 (from foot-of-the-wave analysis), which is comparable to the activity of the state-of-the-art catalyst [Ru-IV(tda)(O)(py)(2)].

Highly microporous humins were synthesized from readily available sugars and bio-based polymers (monosaccharides, disaccharides, and polysaccharides) in sulfuric acid followed by a diethyl ether wash and heat treatment at 400 degrees C. The relative sustainability, costs of production, and availability of the starting materials were improved significantly as compared with the 5-hydroxymethyl-furfural-based microporous humins recently studied by us. A multipronged approach was used to study the detailed characteristics of the adsorbents. Results from H-1 NMR, C-13 NMR, FTIR, WAXS, and elemental analysis were combined and showed that the adsorbents predominantly consisted of amorphous and aromatic carbon structures being rich in oxygen. They were highly porous, and the micropore volumes varied among the compositions as could be observed by analyzing CO2 and N-2 gas adsorption data. Comparably high CO2 uptakes of 4.25 and 1.94 mmol/g at 0 degrees C and 1 and 0.15 bar were observed. With the synthesis of microporous humins with varying porosities, the domain of potential applications of this class of materials could be expanded.

TEMPO-oxidized cellulose nanofibrils (TOCN) are pH-responsive biopolymers which undergo sol-gel transition at acidic conditions (pH < 4) due to charge neutralization. Electronically conducting materials can be coated by such gels during aqueous electrolysis, when an electrochemical reaction generates a local pH decrease at the electrode surface. In this work, electro-precipitation of different TOCN gels has been performed on oxygen evolving anodes. We demonstrate that TOCN hydrogels can be electrochemically coated on the surface of any conductive material with even complex 3D shape. Further, not only TOCN but also micro- or nanosized particles containing TOCN composites can be coated on the electrode surface, and coatings containing multiple layers of different composites can be also produced. We demonstrate that this simple and facile electrocoating technique can be subject to various applications, such as coatings making electrodes selective for the hydrogen evolution reaction, as well as a new eco-friendly aqueous-based synthesis of Li-ion battery electrodes.

Direct quaternization of 1-methyl-1,2,4-triazole with n-alkyl methanesulfonates (alkyl = butyl, octyl, dodecyl) showed to be an atom-economic, convenient, mild, solvent- and halide-free way to obtain 1,2,4-triazolium methanesulfonate ionic liquids in high purity and yield. Subsequent metathesis with lithium bis(trifluoromethanesulfonyl)amide (LiTf2N) allows for a much desired, easy access to halide-free, bis(trifluoromethanesulfonyl)amide ionic liquids. Differential scanning calorimetry confirms that all investigated compounds qualify as ionic liquids (ILs). Moreover, it reveals for 1-methyl-4-n-dodecyl-1,2,4-triazolium methanesulfonate a rather complex thermal behavior involving formation of mesophases. Indeed, polarizing optical microscopy shows oily streaky textures that are characteristic for smectic liquid crystalline phases. Single-crystal X-ray diffraction structure analysis confirms formation of a layered structure. All compounds are photoluminescent. The color of fluorescence at room temperature can be tuned from blue to orange through the length of the alkyl side chain of the cation, the aromatic interactions between the cations, and the anion nature. In addition, at low temperatures (77 K) a close to white phosphorescence with average lifetimes in the millisecond time range can be observed for 1-methyl-4-n-butyl-triazolium methanesulfonate and all of the studied bis(trifluoromethanesulfonyl)amide ILs. All ILs show an appreciable liquidus range and thermal (up to 260-350 degrees C) and electrochemical stability. The presented set of ILs overcomes the sometimes problematic acidity and low stability of imidazolium ILs in basic environment and can be obtained easily in high purity without halide contamination. Overcoming two shortcomings of classical imidazolium ILs, they may be good alternatives for a number of applications and even enabling new ones.

The development of green and sustainable routes to liberate crystalline cellulose microfibrils from plant cell walls is of utmost importance to enable development of the large-scale production of sustainable nanomaterials based on renewable resources. The catalytic oxidation of cellulose using 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO) under aqueous conditions at room temperature is a position-selective and efficient chemical modification. TEMPO-mediated oxidation of plant cellulose fibers, followed by gentle mechanical disintegration of the oxidized celluloses in water, results in the formation of TEMPO-oxidized cellulose nanofibers (TOCNs) with homogeneous widths (similar to 3 nm) and high aspect ratios. TOCNs are characteristic bio-based materials with high tensile strengths and elastic moduli. Sodium carboxylate groups are densely present on the crystalline TOCN surfaces and can undergo counterion exchange from sodium to other metal or alkylammonium ions under aqueous conditions. The hydrophilic/hydrophobic, stable/biodegradable, super deodorant, catalytic, and other functionalities of TOCNs can be controlled through counterion exchange.

Cellulose nanofibrils (CNFs) are a unique nanomaterial because of their abundant, renewable, and biocompatible origin. Compared with synthetic nanoparticles, CNFs are commonly produced from cellulose fibers (e.g., wood pulp) by repetitive high-shear mechanical disintegration. Yet, this process is still highly demanding in energy and costly, slowing down the large-scale production and commercialization of CNFs. Reducing the energy consumption during fibers fibrillation without using any chemical or enzymatic pretreatments while sustaining the CNF quality is challenging. Here, we show that the anisotropic properties of the CNF foams are directly connected to the degree of nanofibrillation of the cellulose fibers. CNFs were produced from wood pulps using a grinder at increasing specific energy consumptions. The anisotropic CNF foams were made by directional ice templating. The porous architecture, the compressive behavior of the foams, and the CNF alignment in the foam cell walls were correlated to the degree of fibrillation. A particular value of specific energy consumption was identified with respect to the highest obtained foam properties and CNF alignment. This value indicated that the optimal degree of fibrillation, and thus CNF quality, was achieved for the studied cellulose pulp. Our approach is a straightforward tool to evaluate the CNF quality and a promising method for the benchmarking of different CNF grades.

Polysaccharides are attractive sustainable resources for the fabrication of advanced materials, but the assembly of these building blocks into complex-shaped structures combining the high strength and low weight required in many applications remains challenging. We have investigated and optimized the rheological and mechanical properties of polysaccharide-based composite foams based on mixtures of methylcellulose (MC), cellulose nanofibrils (CNF), montmorillonite (MMT), and glyoxal and tannic acid. Such foams were found to be stabilized by the coadsorption of MC, CNF, and MMT at the air-water interface, while the complexation of the polysaccharides with tannic acid improved the foam stability. Tannic acid could also be used to tune and optimize the microstructure and the viscoelastic properties of the wet foam for direct ink writing of robust cellular architectures. Glyoxal had no noticeable effect on the properties of the wet foams but significantly enhanced the water resilience and stiffness of the lightweight material obtained after drying at ambient pressure and elevated temperatures with minimum shrinkage. The foams possessed a high porosity and displayed a specific Youngs modulus and yield strength that outperformed other biobased foams and commercially available expanded polystyrene. The strong and water-resilient 3D printed foams can be surface modified using, for example, aminosilanes, which opens up applications for air purification and thermal insulation.

A series of sustainable activated carbons (ACs) with large surface areas and tunable pore sizes is synthesized from Cladophora cellulose and its chemically modified derivatives in a one-step physical carbonization/activation process. The molecular structure of the cellulose precursors and the carbonization/activation atmosphere (N-2 or CO2) significantly influence the pore structure of the ACs. When using oxidized cellulose and its further cross-linkages as the precursor, the ACs have a large volume of ultramicropores (pore diameter < 0.8 nm). Activation in CO2 results in ACs with surface areas up to 1241 m(2) g(-1). These ACs have a high CO2 uptake capacity (2.29 mmol g(-1) at 0.15 bar, 5.52 mmol g(-1) at 1 bar; 273 K) and a high CO2-over-N-2 selectivity (42 at 273 K). In addition, the capacity of the ACs to adsorb vapors of volatile organic compounds (VOCs) is remarkable, with values up to 0.97 mmol g(-1) at very low VOC concentrations (200 ppmv). The ACs have ultrahigh VOCs-over-N-2 selectivity up to 9.35 x 10(3) at 293 K for 0.02 vol%/99.8 vol% of benzene/N-2 mixture. It is anticipated that these ACs will be useful as sorbents for the postcombustion capture of CO2 and for indoor removal and direct air capture of various VOCs.

Nanocrystalline Sr1-xBaxSnO3 (x=0, 0.2, 0.4, 0.8, 1) perovskite photocatalysts were prepared by microwave synthesis in an ionic liquid (IL) and subsequent heat-treatment. The influence of the Sr/Ba substitution on the structure, crystallization, morphology, and photocatalytic efficiency was investigated and the samples were fully characterized. On the basis of X-ray diffraction results, as the Ba content in the SrSnO3 lattice increases, a symmetry increase was observed from the orthorhombic perovskite structure for SrSnO3 to the cubic BaSnO3 structure. The analysis of the sample morphology by SEM reveals that the Sr1-xBaxSnO3 samples favor the formation of nanorods (500nm-5m in diameter and several micrometers long). The photophysical properties were examined by UV/Vis diffuse reflectance spectroscopy. The band gap decreases from 3.85 to 3.19eV with increasing Ba2+ content. Furthermore, the photocatalytic properties were evaluated for the hydroxylation of terephthalic acid (TA). The order of the activities for TA hydroxylation was Sr0.8Ba0.2SnO3>SrSnO3>BaSnO3>Sr0.6Ba0.4SnO3>Sr0.2Ba0.8SnO3. The highest photocatalytic activity was observed for Sr0.8Ba0.2SnO3, and this can be attributed to the synergistic impacts of the modification of the crystal structure and morphology, the relatively large surface area associated with the small crystallite size, and the suitable band gap and band-edge position.

Environmentally friendly and cost-effective Li-ion cells are fabricated with abundant, non-toxic LiFePO4 cathodes and iron oxide anodes. A water-soluble alginate binder is used to coat both electrodes to reduce the environmental footprint. The critical reactivity of LiPF6-based electrolytes toward possible traces of H2O in water-processed electrodes is overcome by using a lithium bis(oxalato) borate (LiBOB) salt. The absence of fluorine in the electrolyte and binder is a cornerstone for improved cell chemistry and results in stable battery operation. A dedicated approach to exploit conversion-type anodes more effectively is also disclosed. The issue of large voltage hysteresis upon conversion/de-conversion is circumvented by operating iron oxide in a deeply lithiated Fe/Li2O form. Li-ion cells with energy efficiencies of up to 92% are demonstrated if LiFePO4 is cycled versus such anodes prepared through a prelithiation procedure. These cells show an average energy efficiency of approximately 90.66% and a mean Coulombic efficiency of approximately 99.65% over 320 cycles at current densities of 0.1, 0.2 and 0.3 mAcm(-2). They retain nearly 100% of their initial discharge capacity and provide an unmatched operation potential of approximately 2.85 V for this combination of active materials. No occurrence of Li plating was detected in three-electrode cells at charging rates of approximately 5C. Excellent rate capabilities of up to approximately 30C are achieved thanks to the exploitation of size effects from the small Fe nanoparticles and their reactive boundaries.