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In this study, a heat-resistant and high-wettability lithium-ion batteries separator (PI-CPM-PI) composed of cellulose nanofibers (CNF) and aramid fibers (PMIA chopped fiber/PPTA pulp) with the reinforced concrete structure was fabricated via a traditional heterogeneous paper-making process. CNF played crucial roles in optimizing the pore structure and improving the wettability of PI-CPM-PI separator. The effects of composition on separator properties were investigated and the results indicated that the optimal compositions were 0.5 wt% CNF, 0.5 wt% PMIA chopped fiber/PPTA pulp (ratio of 5:5), 0.05 wt% diatomite and 1.5 wt% polyimide. Relevant tests demonstrated that the performance advantages of PI-CPM-PI separators were exhibited at the wettability and thermal stability compared to the commercial separator (PP). Additionally, batteries assembled with PI-CPM-PI separators showed excellent electrochemical and cycling performance (ionic conductivity of 1.041 mS.cm−1, the first discharge capacity of 158.2 mAh.g−1 at 0.2C and capacity retention ratio of 99.76 % after 100 cycles). • CPM membrane was prepared by heterogeneous process with vacuum assisted filtration. • PI-CPM-PI separator had function design of reinforced concrete structure. • PI-PI micro-crosslinking structure was formed by spraying and mixing method. • The DTM caused the enhancement of wettability and thermal stability of separators. • PI-CPM-PI separator had good wettability, thermal stability and electrochemical. [ABSTRACT FROM AUTHOR]

In view of the deficiencies in the preparation of cellulose gels, such as, cumbersome process, harsh conditions, high consumption of chemicals, secondary pollution caused by side reactions, this work reports a facile approach to make cellulose/multi-walled carbon nanotube (MWCNTs) hydrogels and aerogels via mixing cellulose with N , N ′-methylene bisacrylamide (MBA) and MWCNTs in NaOH/urea/H 2 O aqueous solution. The gels were revealed to be formed by an addition reaction between the double bonds of MBA and the hydroxyl groups of cellulose and the intermolecular interactions between cellulose and MWCNTs. The preparation process can be realized at room temperature and atmospheric pressure without the intervention of ultrasonic dispersion, catalyst and initiator. The gelation time, puncture strength and water retention ability of the hydrogels were investigated. Results showed that, compared with pure cellulose hydrogel, cellulose/MWNCTs hydrogels have obviously shorter sol-gel transition time (124–129.2 min), higher puncture strength (29.6022–34.2854 KPa) and water retention ability (274.2619–301.7291 g/g). Cellulose/MWCNTs aerogels possessed three dimensional network with macroporous structure (about 500 μm), low density (0.00546–0.00557 g/cm3), high porosity (99.6360–99.6426 %), good thermal stability (242 °C) and certain absorbency to methylene blue (233.2901–242.1122 mg/g). [ABSTRACT FROM AUTHOR]

Liquid mulching film is an emerging film material to replace the traditional plastic film, which causes wide public concern. In this study, a graft copolymer (LS-AA) was synthesized from sodium lignosulfonate (LS) by free radical polymerization, which was added as enhancer to the cationic starch (CS) solutions to obtain the CLA based film. The grafting conditions was optimized by response surface methodology (RSM) for the preparation of LS-AA, after that the LS-AA was characterized by FTIR, XRD, and TG. The highest grafting rate was obtained under the reaction conditions of 80 °C for 2.6 h with the mass ratio of monomer and LS of 5.5/5 at initiator dosage of 1 %. The fabricated liquid mulching film with addition of LS-AA showed outstanding anti-ultraviolet, biodegradation, anti-erosion, which provided theoretical base and practical references for popularizing and application of liquid mulching film in the dust prevention and sand fixation. [ABSTRACT FROM AUTHOR]

Highlights: [•] Redistribution of chemical compositions occurs during the process of size classification. [•] Glucan conversion is affected synthetically by the augment of surface area, lignin enrichment, and cellulose decrystallization that accompany with the process of size reduction. [•] Diversity of woody recalcitrance in bioconversion is reflected by the distinguishing responses of enzymatic digestibility to size reduction. [Copyright &y& Elsevier]

The origin and kinetic changes of carboxyl groups in aspen chemithermomechanical pulp (CTMP) fibres during alkaline peroxide bleaching were evaluated. The results showed that the major contributors of carboxyl groups in aspen CTMP fibres were the 4-O-methylglucuronic acid, galacturonic acid and the carboxyl groups in oxidized lignin. Alkaline peroxide bleaching could increase the total carboxyl groups, surface charge and dissolved anionic substances. However, the excess degradation by superfluous hydroxide and peroxide could result in the reduction of carboxyl groups in fibres because of the production and dissolution of low-molar-mass substances. The total carboxyl groups from polysaccharides in fibres remained constant, and the increase of carboxyl groups in fibres should result from the carboxyl groups newly formed by the lignin oxidation during peroxide bleaching. Alkaline peroxide bleaching could also result in the removal of a large part of extractives and a small fraction of lignin on the fibre surface. [ABSTRACT FROM AUTHOR]

Abstract: Rejects from sulfite pulp mill that otherwise would be disposed of by incineration were converted to ethanol by a combined physical–biological process that was comprised of physical refining and simultaneous saccharification and fermentation (SSF). The energy efficiency was evaluated with comparison to thermochemically pretreated biomass, such as those pretreated by dilute acid (DA) and sulfite pretreatment to overcome recalcitrance of lignocelluloses (SPORL). It was observed that the structure deconstruction of rejects by physical refining was indispensable to effective bioconversion but more energy intensive than that of thermochemically pretreated biomass. Fortunately, the energy consumption was compensated by the reduced enzyme dosage and the elevated ethanol yield. Furthermore, adjustment of disk-plates gap led to reduction in energy consumption with negligible influence on ethanol yield. In this context, energy efficiency up to 717.7% was achieved for rejects, much higher than that of SPORL sample (283.7%) and DA sample (152.8%). [Copyright &y& Elsevier]

Abstract: The viscosity, wettability and deposition tendency of spruce thermomechanical pulp resin extracted with hexane, acetone and hexane–acetone (9:1, v/v) were studied in this paper. Some hydrophilic substances such as sugars and lignans could be extracted by some hydrophilic solvents, and the effect of the hydrophilic substances on physico-chemical properties is still not well known. The results showed that hydrophilic substances such as lignans and sugars present in spruce thermomechanical pulp resin had a great effect on resin physico-chemical properties. About 19% sugars and 14% lignans were identified in the acetone extracts, which could increase resin viscosity greatly. Only a little of lignans and sugars could be extracted by hexane–acetone, but these sugars and lignans could increase resin hydrophilicity evidently, leading to the decrease in contact angles with water and the increase in the acid–base component of work of adhesion. During preparation of resin dispersions, however, these sugars and lignans dissolved in dispersions could pass through the pores of the dialysis tube into water system which would cause an unexpected deposition result of the acetone-extracted resin dispersion. Resin extracted with hexane can be regarded as a relative ideal resin model in evaluating resin deposition tendency. [Copyright &y& Elsevier]

Abstract: Old newsprint (ONP) could be deinked with laccase–violuric acid system (LVS). To study the mechanism of LVS deinking, lignins from the control and LVS-deinked pulp were isolated and characterized by chemical, spectroscopic and chromatographic methods. The molecular weight change of lignin was tracked by gel permeation chromatogram (GPC), and structural changes in lignin extracted from the control and LVS-deinked pulps were characterized by elemental analysis, functional groups measurement, FT-IR, 1H NMR and 1H–13C correlation 2D NMR. The experimental results showed that the molecular weight of lignin from LVS-deinked pulp was lower than that of lignin from the control pulp. The contents of free phenolic hydroxyl groups and methoxyl groups of lignin from LVS-deinked pulp decreased, while the contents of carboxyl and carbonyl groups increased. Guaiacyl units in lignin were oxidized by LVS. Stilbene and 5–5′ substructures in lignin were stable to LVS treatment, while β-O-4 and β–β substructures were partially destroyed during the LVS deinking. According to structural changes in lignin, the mechanism of LVS deinking was deduced. [Copyright &y& Elsevier]

A set of model resin mixtures were prepared to simulate Norway spruce thermomechanical pulp (TMP) resin at different conditions, such as in winter or summer, or after lipase and/or steryl esterase treatments. The resin samples were analysed on their viscosity, tackiness, wettability and surface energy; properties which may be related to the deposition tendency of wood resin. During production of mechanical pulps, large amounts of wood resin are dispersed into the process waters, which may later on aggregate and deposit onto paper machine equipment or the formed sheet, thus affecting the runnability of the paper machine as well as the quality of the paper. It is, therefore, important to understand which physico-chemical properties of the wood resin may influence its deposition tendency. The results showed that resin acids, steryl esters, and especially sterols had a much stronger effect on resin viscosity than the lower-viscosity fatty acids and triglycerides. The surface energy measurements showed that steryl esters and triglycerides were the most hydrophobic components. The resin acids, fatty acids and sterols gave the highest value for the acid-base (AB) component of the work of adhesion (Wa). Model resin mixtures with high amounts of one or more of these three components also showed a higher AB component of the Wa. In light of this, a model for the wood resin droplet was proposed. Colloidal droplets released from spruce TMP tend to form a two-layered droplet structure. The hydrophobic steryl esters and triglycerides form the core and main body of the resin droplets, while the resin acids, fatty acids and sterols, are enriched at the outer surface with the carboxyl and hydroxyl groups extending into the water. Because of the high viscosity of resin acids and sterols, the exterior part may be a viscous film. Although the exterior part is much thinner than the interior, it probably plays a much more important role in determining resin properties, such as chemical reactivity, charge, colloidal stability and pitch deposition tendency. [Copyright &y& Elsevier]

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

This work aimed to construct a polysaccharide-based mulch film with good performance for replacing plastic mulch by coating the glutaraldehyde crosslinking chitosan and humic acid/urea complexes (GCS) into cellulose/humic acid (HA/CE) film. By flow-coating with GCS to construct hierarchical networks, GCS-HA/CE film is endowed with the improved property. The influences of composition with different concentrations on mechanical properties were studied, and the optimum concentration was determined. The tensile strength and elongation of GCS-HA/CE film could reach 53.97 MPa and 12.86 % in dry state, respectively. Results suggest that glutaraldehyde crosslinking reduces moisture content, water solubility, and water vapor permeability, but increases contact angle (94.025°). Meanwhile, the thermostability and ultraviolet resistance were improved. The infrared spectroscopy and X-ray diffractometry demonstrated the successfully crosslinked by glutaraldehyde. Morphological analyses present film has excellent compatibility. In addition, GCS-HA/CE film shows good heat preservation, aging resistance, and biodegradability, indicating certain guiding significance for polysaccharide-based mulch film. [Display omitted] [ABSTRACT FROM AUTHOR]

Solar desalination devices utilizing sustainable solar energy and the abundant resource of seawater has great potential as a response to global freshwater scarcity. Herein, a bilayered solar evaporator was designed and fabricated utilizing a facile paper sheet forming technology, which was composed of cellulose fibers decorated with Fe3O4 nanoparticles as the top absorbent layer and the original cellulose fibers as the bottom supporting substrate. The characterization of the cellulose fibers decorated with Fe3O4 nanoparticles revealed that the in situ formed Fe3O4 nanoparticles were successfully loaded on the fiber surface and presented a unique rough surface, endowing the absorber layer with highly efficient light absorption and photothermal conversion. Moreover, due to its superhydrophilic property, the cellulose fiber-based bottom substrate conferred ultra-speed water transport capability, which could enable an adequate water supply to combat the water loss caused by continuous evaporation on the top layer. With the advantages mentioned above, our designed bilayered paper-based evaporator achieved an evaporation rate ~1.22 kg m−2 h−1 within 10 min under 1 sun irradiation, which was much higher than that of original cellulose cardboard. Based on the simple and scalable manufacture process, the bilayered paper-based evaporator may have great potential as a highly efficient photothermal conversion material for real-world desalination applications. [ABSTRACT FROM AUTHOR]

In recent years, researchers have put much attention on the improvements and upgrades of novel wet strength agent in the papermaking fields, especially in the usage of household paper. Herein, PEI M -KH560 by polyethyleneimine (PEI) and γ-glycidyl ether propyl trimethoxysilane (KH560) was synthesized with five molecular weights (Mw) of PEI at 600, 1800, 10,000, 70,000 and 750,000. Results showed that the molecular weight greatly influenced the physicochemical properties of PEI-KH560, such as the size and thermal stability. The intrinsic cationic charge of PEI-KH560 provided the bonding sites with the paper fibers, forming strengthened fiber-fiber joints. It was shown that the dry, wet strength and hydrophobicity of cellulosic paper sheets were obviously improved. When the m (PEI):m(KH560) is 1:2, the strength of papers after sizing by Mw of PEI at 600 and 1800 is the most obvious, with the dry strength increased by 227.9 % and 187.5 %, and the wet strength increased by 183.8 % and 207.8 %, respectively. The maximum hydrophobicity was found at the PEI 1800 -KH560 with the contact angle value of 130.6°. The resultant environmental-friendly agent (PEI-KH560) obtained in this work provides valuable significance for the preparation of household and food packaging paper. • Chlorine-free agents were prepared by different molecular weight of PEI and KH560. • The size and carbon residue content of PEI-KH560 were related with Mw of PEI. • PEI-KH560 significantly enhanced the wet strength of papers after surface sizing. • Mw of PEI influenced the strength and hydrophobicity of sized papers obviously. • The tensile strength was most effective at PEI M w of 600 with an increase of 227 %. [ABSTRACT FROM AUTHOR]

The Jinyang Basin is a typical volcanic-sedimentary basin, located in the southern peripheral area of the Songliao Basin. Hydrothermal activity is often closely related to the intrusion or eruption of magma. It was recently suggested that dolomite in the Jurassic Beipiao Formation was formed under the influence of magmatic-hydrothermal activity and magmatic-hydrothermal activity might have impacts on the organic matter of the source rocks. No investigation has been aimed at the effect of magmatic-hydrothermal activities on the accumulation of organic matter in the Beipiao Formation source rocks and a comprehensive study is urgent, which would be indicative in unravelling the accumulation mechanism of organic matter and useful in further petroleum exploration. To provide important insights into these issues, we carried out a detailed investigation of geological and geochemical analysis for Wolong (WL) and Dongkuntouyingzi (DK) outcrop shales from the Lower Jurassic Beipiao Formation in the Jinyang Basin. The hydrothermal indicator discrimination diagram (Zn-Ni-Co triangular plot) and rare earth element anomalies (δEu and δCe) indicate that the formation of WL samples is associated with hydrothermal activity, but DK is not. The TOC values suggest that most of the WL and DK samples are good to very good and fair to good source rocks, respectively. The Ro values suggest that both WL (Ro = 1.17%) and DK (Ro = 1.01%) samples have entered the oil-generating stage, and WL samples were influenced by the magmatic activity with higher maturity. The biomarkers such as high steranes/hopanes, high 4-methyl steranes/C29 steranes, low Pr/Ph values and high gammacerane index suggest that WL samples were deposited in an anoxic-prone saline environment with significant contributions of algal sources. Contrarily, the DK samples were deposited in oxic-prone and freshwater paleolake with significant contributions of terrigenous organic matter. The magmatic-hydrothermal activities in the Wolong area brought numerous nutrients to the lake basin, which may facilitated the reproduction of aquatic organisms. At the same time, the magmatic-hydrothermal activities increased the salinity of water and promoted the formation of a water reducing environment, which provided an excellent environment for the preservation and enrichment of organic matter. Therefore, the magmatic-hydrothermal activities in the Wolong area promoted the formation of organic-rich source rocks and the hydrocarbon generation process. [ABSTRACT FROM AUTHOR]

Abstract: Nanocrystalline cellulose (NCC) isolated from bleached aspen kraft pulp was characterized, and its application as pulp strengthening additive and retention aid was investigated. Results showed that NCC with high crystallinity of more than 80% can be obtained using 64wt% sulfuric acid. The structure of nanocrystalline cellulose is parallelepiped rod-like, and their cross-sectional dimension is in the nanometer range with a high aspect ratio. The formation of microparticle retention systems during the application of NCC together with cationic polyacrylamide and cationic starch in deinked pulp was able to further improve pulp retention and strength properties without negative influence on the drainage. [Copyright &y& Elsevier]

Abstract: The effect of alkaline peroxide bleaching on the total anionic groups (AGs) and surface AGs in aspen chemithermomechanical pulp (CTMP) fibers was investigated. Alkaline treatment, especially alkaline peroxide bleaching resulted in the formation of new AGs and surface AGs in the CTMP fibers. The carboxylic groups in uronic acid units, including 4-O-methylglucuronic acid, galacturonic acid, and glucuronic acid units were the main contributors to the AGs in the fibers. However, the oxidized lignin accounting for more than 30% of the total AGs in the bleached CTMP fibers, was the main origin of the new AGs formed during the peroxide bleaching. In addition, the new AGs were also formed by extensive deesterification of the residual esterified uronic acids in pectins and lignin-carbohydrate complexes (LCCs). Although some uronic acid units were dissolved in the process water, both the total AGs and surface AGs in the fibers increased after alkaline peroxide bleaching. [Copyright &y& Elsevier]

An efficient separation technology for hydrolysates towards a full valorization of bamboo is still a tough challenge, especially regarding the lignin and lignin-carbohydrate complexes (LCCs). The present study aimed to develop a facile approach using organic solvent extraction for efficiently fractionating the main components of bamboo hydrolysates. The high-purity lignin with only a trace of carbohydrates was first obtained by precipitation of the bamboo hydrolysate. The water-soluble lignin (WSL) fraction was extracted in organic solvent through a three-stage organic solvent extraction process, and the hemicellulosic sugars with increased purity were also collected. Furthermore, a thorough characterization including various NMR techniques (31P, 13C, and 2D-HSQC), GPC, and GC-MS was conducted to the obtained lignin-rich-fractions. It was found that the WSL fraction contained abundant functional groups and tremendous amount of LCC structures. As compared to native LCC of bamboo, the WSL fraction exhibited more typical LCC linkages, i.e. phenyl glycoside linkage, which is the main type of chemical linkage between lignin and carbohydrate in both LCC samples. The results demonstrate that organic phase extraction is a highly efficient protocol for the fractionation of hydrolysate and the isolation of LCC-rich streams possessing great potential applications. [ABSTRACT FROM AUTHOR]

In this study, the base film (CSL) was prepared by blending tunicate cellulose nanocrystals (TCNCs) extracted from tunicate shells, with sodium alginate (SA) and alkali lignin (AL). Then, the mulching film (CSL-WK) was prepared using water-borne polyurethane (WPU) as binder to install low-energy Kaolin on the surface of CSL film. The influences of composition with different concentrations on mechanical properties were studied. The tensile strength and elongation at break of CSL-WK film could reach 86.58 MPa and 50.49 %, respectively. The mulching films were characterized by degradability test, SEM, FTIR, and TGA. TCNCs had good compatibility with SA and AL, and a rough structure was formed on the surface of the film to improve the hydrophobicity. The barrier properties, including ultraviolet resistance, water contact angle, water vapor permeability, water retention, and flame retardancy, were tested. The results showed that CSL-WK films could block 97 % of ultraviolet light, reduce about 25 % of soil water loss, and self-extinguish within 7 s of open flame ignition. Note that the secondary spraying method significantly improved the barrier property of films. This study lays a foundation for the preparation of ecologically friendly, biodegradable, and high barrier mulching film, and expands the application of marine resources. • The shells of the tunicates were firstly used to prepare mulching films. • Multiple biomass materials were used to prepare high barrier mulching film materials. • The film has excellent UV resistance, water vapor barrier, and flame retardancy. • The mechanical strength and barrier properties were improved by spraying process. • High b biomass mulch supports environmentally friendly agricultural practices. [ABSTRACT FROM AUTHOR]

Integrated fractionation process based on autohydrolysis (H) and subsequent formic acid delignification (FAD) has been considered as an effective strategy to separate the main lignocellulosic components in view of the biorefinery. For the better understanding of the structural changes of the lignin during the integrated process, the fractionated aspen lignins were thoroughly characterized by Fourier transform infrared (FT IR), 13C, two-dimensional heteronuclear single quantum coherence (2D-HSQC) and 31P nuclear magnetic resonance (NMR) spectroscopy, gel permeation chromatography (GPC), and thermogravimetric analysis (TGA). Compared to the milled wood lignin (MWL), the fractionated lignins had higher amounts of phenolic OH groups as due to the cleavage of β-O-4 linkages and less alcoholic OH groups mainly due to the esterification of the aliphatic OH groups by formic acid. Demethylation action of the lignin was not significant during the FAD process. More syringyl-propane (S) units were extracted during the H-FAD process than guaiacyl-propane (G) units resulting in a higher S/G ratio and more OCH 3 in the fractionated lignins. Furthermore, autohydrolysis of aspen at higher temperature led to more condensation of the fractionated lignins which exhibited higher molecular weight and more β-5 and β-β linkages. The fractionated lignins exhibited high purities due to the breakage of the lignin-carbohydrate bonds. • Lignin with high phenolic OH and OCH 3 and high purity was obtained. • Aliphatic OH group was highly esterified by formic acid. • β-O-4 cleavage accompanied by formation of condensed aromatic structure • Autohydrolysis led to higher molecular weight and less formate ester in lignin [ABSTRACT FROM AUTHOR]

The removal of lignin is important to the recovery of saccharides from the pre-hydrolysis liquor (PHL) in kraft-based dissolved pulp production. A one-step process for lignin removal from PHL via treatment with horseradish peroxidase (HRP) in the presence of Ca2+ was proposed, and its principle was studied. The results demonstrated synergy between HRP and Ca2+ in lignin removal from PHL, whereas NH 4 + had little effect on lignin removal. HRP treatment in the presence of 60 mmol/L of Ca2+ resulted in a lignin removal of 64.8% accompanied by a saccharide loss of 14.2%. HRP catalyzed both the polymerization and depolymerization of the lignin in the PHL. The HRP-catalyzed lignin polymerization rendered some lignin insoluble enabling it to be directly removed. The HRP-catalyzed depolymerization of lignin decreased its molecular weight with an evident increase in its carboxyl content. The insoluble complexes formed between the lignin with carboxyl and the Ca2+ facilitated the removal of the depolymerized lignin. • A new one-step process for effective lignin removal from PHL was proposed. • Synergy existed between HRP and Ca2+ in lignin removal from PHL. • HRP treatment in the presence of 60 mmol/L of Ca2+ yielded 64.8% lignin removal. • HRP treatment increased the carboxyl content of soluble lignin in PHL. • Complexes formed between Ca2+ and the carboxyl of soluble lignin to facilitate lignin removal. [ABSTRACT FROM AUTHOR]

A practical method for the preparation of lignin derivatives-light-colored bio-based particles (LC-BP) via the modification of hexamethylene diisocyanate (HDI) is presented in this work. In the mixed EtOH/H 2 O system, the change of solvent polarity induced the self-assembly of the lignosulfonate (LS) with the hydrophobic chromophores encapsulated inside the particles. The color of LS was reduced by the polymerization between the isocyanate groups (-N=C=O) of HDI and hydroxy groups of LS. Compared with the typical lignin-based adsorbent preparation process in the past, this is a simple, direct, and efficient preparation method and the synthetic LC-BP has good chemical stability and resistance to heat, acid and alkali. This effectively solves the problem that LS has high water solubility and is difficult to use directly for wastewater treatment. To investigate the properties, the synthetic LC-BP was characterized by SEM, specific surface area, L*a*b* (CIELAB) color space, FT-IR, XPS, and TGA. The results showed that the LC-BP exhibited obvious advantages in color reduction with a low CIE-L* value. The LC-BP exhibits a scale-like intercalation structure, which makes it a promising candidate for adsorbing tetracycline (TC) from wastewater. The conditions of pH, adsorbent dosages, adsorption time, and initial TC concentration were investigated, and the adsorption performance of LC-BP for TC was significantly better than that of conventional polyurethane particles (PP). The adsorption fitted the Langmuir model and there were hydrogen bonding, π-π conjugated binding, and electrostatic attraction during the absorption process. The adsorption capacity was up to 53.1 mg/g, and the removal rate was 67 %. The utilization of LC-BP, a low-cost, effective, and renewable resource derived from natural biomass, holds immense practical and economic potential in wastewater treatment. [Display omitted] • A practical method for the preparation of light-colored lignin • The theoretical basis of lignin-based biomacromolecular compounds was proposed. • Rearrange chromophoric groups of lignin by isocyanate modified • The product can be used as efficient adsorbent for colored wastewater. [ABSTRACT FROM AUTHOR]

Solar steam evaporation exhibits great potential in solving the global shortage of freshwater resources. However, salt accumulation at the top photothermal conversion surface has severely limited the desalination efficiency and stability of solar desalination systems. Herein, we demonstrated a nature-inspired salt resistant bilayered evaporator by using a slight delignificated tree root as bottom substrate and decorated graphene oxide layer as the top absorber surface. The naturally design of tree root inherently exists multilevel vertical channels interconnected porous microstructures. This distinctive structure of tree root allows ultra-high-speed water transport capability and rapid multi-directional salt exchange, enabling it to possess anti-salt-accumulation properties for solar steam generation. This designed tree root-based evaporator effectively prevented salt accumulation while maintaining a fast and stable evaporation rate, which exhibited an evaporation rate of 1.60 kg m−2 h−1 with excellent long-term stability in a high-salinity brine (21 wt%) under 1 sun irradiation. Taking the unparalleled advantages, our designed tree root-based evaporator obtained by a facile fabrication method represents a high-efficacy and stable fresh water production platform for practical applications in water purification. [Display omitted] • The unique microstructure of tree root makes it a "natural choice" as solar evaporator. • Natural multiscale channeled structure allows rapid multi-directional salt exchange. • Tree root based solar evaporator exhibits ultra-high-speed water transport capability. • A super-high and stable conversion efficiency of 96.5% was obtained. • This work showed a high-efficacy and long-term stable seawater desalination platform. [ABSTRACT FROM AUTHOR]

Highly hydrophobic fabrics by chelating lignin (alkali lignin, sodium lignin sulfonate and formic acid lignin) with metal ions (Fe3+, Fe2+ and Cu2+) were prepared with the surface wettability from superhydrophilic to highly hydrophobic. The lignin/metal chelated particles are in-situ deposited onto the fabric surface using dip-coating. Different lignin/metal ion system influenced the construction of hierarchical surface roughness and energy of fabrics greatly. Specially, the formation of homogeneous spherical particles on surface contributed to the minimal contact area of water droplets and fabric, and thus avoiding their adherence. The surface morphology results showed that the active groups of lignin is closely related with the surface roughness. It was found that the alkali (AL)/FeⅢ@cotton fabric achieved a maximum water CA value of 149.9° and a low surface energy of 1.90 mN/m. Its oil-water separation efficiency was higher than 99.9% and the resultant AL/FeⅢ@cotton fabric owned an excellent stability and suitability under harsh conditions. Collectively, this work is greatly significant for achieving the high-value utilization of lignin in wastewater treatments. [Display omitted] ● In-situ deposition of lignin/metal ion lowered the surface energy of fabrics. ● Phenolic hydroxyl content of lignin affected the size of lignin/metal chelates. ● Deposited lignin/metal chelates influenced the durable hydrophobicity of fabrics. ● Al/Fe3+ conferred the fabric highest hydrophobicity with the WCA value of 149.9°. ● The resultant fabric exhibited an excellent oil-water separation and stability. [ABSTRACT FROM AUTHOR]

[Display omitted] • Fe2+-coordination induced the deposition of LG on cotton fabric via dip-coating. • Hierarchical structures formed on fabric surface are revealed by SEM and AFM images. • Growth mechanism of micro-nano particles by LG/Fe coordination is disclosed. • The fabric gets an outstanding oil/water separation capacity and stability. Developing eco-friendly and easily accessible material using an easy and environmental-friendly approach is desired and shows promise in treating oil pollution spills. Herein, Fe2+ was used as a green binder of lauryl gallate (LG) to improve the hydrophobicity of cotton fabric via dip-coating. Specifically, LG and Fe2+ forms hierarchical micro-nano structures that were firmly attached on the fabric surface after co-deposition. The physicochemical properties of LG/Fe2+ hybrid solution and particles were evaluated, and the surface properties of cotton fabric changed from superhydrophilic to highly hydrophobic. Results showed that LG/Fe@fabric owned a water contact angle value of 136.6°, due to the increased surface roughness confirmed by the SEM and AFM images. Besides, the resultant fabric achieved an outstanding self-cleaning and superior oil–water separation performance in the simulated various oil–water separation experiments. Remarkably, this fabric acquired an excellent stability under severe conditions (e.g. erosion in organic, acidic, salty and basic aqueous solutions, extreme temperatures and ultraviolet radiation). Moreover, this strategy is suitable for many other fabric matrixes as well. In a word, this work is extremely significant for the treating of oily waste water via a green and simple strategy, and realizing their high value utilization of cotton fabric at the same time. [ABSTRACT FROM AUTHOR]

The majority of current oral drugs are hydrophobic, and have the toxic side effects to the gastrointestinal tract, which limit their therapeutic efficacy. In order to improve the performance of drug formulations, the development of new functional materials is crucial for the technological breakthroughs in the pharmaceutical industry. The antimicrobial and antioxidant properties of lignin nanoparticles (LNPs) give them great potential for application in this field. LNPs consist of a hydrophilic shell and hydrophobic core, which is particularly suitable for the capsulation of hydrophobic drugs, and then it would increase the stability and solubility of drugs and reduced the irritation to the stomach. In this study, alkali lignin (AL) was fractionated by 80% methanol to obtain targeted MAL with low molecular weight, high phenolic hydroxyl content and good homogeneity. The LNPs was prepared by quaternization modification of MAL and self-assembling in an ethanol/water mixture. Their application in the hydrophobic oral drug delivery system was evaluated and Ibuprofen (IBU) was used as a drug pattern. The effect of solvent exchange time (24 h, 36 h, 48 h and 60 h) on the formation process of IBU-loaded LNPs (IBU-LNPs) was investigated. The in vitro release experiments were conducted and it revealed that IBU release occurred priority in the intestine rather than the stomach, which were meeting the release requirements of ideal oral carrier. In addition, IBU-LNPs showed non-cytotoxic against the L929 cells and improved the bioavailability of IBU drugs. Therefore, this work proposes a preparation method of the smart lignin nanoparticle by screening characteristic lignin with higher reactivity and by modulating the solvent exchange time during the preparation process. Overall, LNPs showed the great potential of application in pharmaceuticals industry and was demonstrated a promising and green product. • Lignin nanoparticles (LNPs) were prepared with the objective of evaluating their application as a novel oral drug delivery system. • The novel LNPs have an optimal size, high encapsulation efficiency, and a sustained pattern of Ibuprofen release in the simulated intestinal fluid, and excellent stability in the gastric condition. • LNPs increase the bioavailability of Ibuprofen and show non-cytotoxic against the normal cells. [ABSTRACT FROM AUTHOR]

• Multifunctional lignin-based hybrid magnetic nanoparticles were synthesized. • The hybrid nanoparticles showed ultrafast adsorption capabilities for Pb2+ and Cu2+. • The abundant active sites from modified lignin enabled high efficiency of adsorption. • Adsorption was driven by ion exchange, hydrogen bonding and electrostatic attraction. Heavy metals have raised an increasing number of pollution incidents and resulted in potent damages to aquatic ecosystems and human health. Thus, effective and efficient approaches to eliminate heavy metal ions are in urgent needs. Herein, novel hybrid nanoparticles have been prepared by a facile method using epichlorohydrin as a cross-linker between amino-functionalized magnetic nanoparticles and carboxymethylated lignin. Multiple characterization methods including XRD, FTIR, XPS, SEM, and TEM confirmed the formed nanostructures and the chemical features of the lignin-based hybrid nanoparticles. The as-synthesized hybrid nanoparticles exhibited high adsorption capacities of 150.33 and 70.69 mg/g for Pb2+ and Cu2+, respectively. More importantly, the adsorption equilibriums of Pb2+ and Cu2+ onto hybrid nanoparticles can be achieved within 30 s, which are among the fastest functional adsorbents for Pb2+ and Cu2+ removal as reported by now. The ultrafast adsorption is ascribed not only to the nanostructures, but also to the abundant active sites provided by the carboxymethylated lignin. The mechanism of removing Pb2+ and Cu2+ by hybrid nanoparticles could be mainly attributed to ion exchange and hydrogen bonding. The tailored nanostructured hybrid nanoparticles with exceptional adsorption effectiveness and efficiency are low-cost and eco-friendly, which potentially meets the cost-effective criteria for producing the water treatment adsorbents on a large scale. [ABSTRACT FROM AUTHOR]

Lignin is the second largest component of vascular plants and is the most abundant renewable aromatic polymer on our planet. The attractiveness of lignin valorization lies in its conversion into high value aromatic chemicals and biofuels through fractionation and upgrading. The literature has demonstrated that the presence of aryl ether bonds in native lignin was a key factor for the conversion, while the conventional technical lignins from carbohydrate-first processes, e.g. pulp and cellulose ethanol production, are intensively condensed and lack these linkages due to the intense delignification conditions. Here, by using the β-O-4 lignin model dimer GG, we reveal the dramatic degradation of GG and the synchronous formation of relatively stable intermediate β-O-4 dimers, C6C3 enol ether and the formylated enol ether, within the first 5 min under the conditions of 72 wt% aqueous formic acid and 130 °C, conditions suitable for biomass fractionation. Based on these findings, we propose a simple but effective strategy of rapid flow-through fractionation (RFF), which separates the dissolved lignin from the reactor in time and space, thereby preserving these labile aryl ether bonds in native lignin. The application of RFF of poplar wood with a short residence time of 2.6 min attained 75% delignification with an equivalent of the β-O-4 motif in native lignin. Structure-preserved lignins (β-O-4 retention, 75.0%–85.4%) were also harvested from wheat straw with good lignin yields (61.7%–78.5%). Contrarily, batch fractionation acted as a protracted war and resulted in extensive cleavage of aryl ether bonds as suggested by 92%–100% loss of the β-O-4 motif under the same conditions. Because of the well-preserved structure, RFF lignin can be used as a good feedstock to boost its downstream valorization, especially for hydrogenolysis into monophenolic chemicals and fuels. It is noteworthy that the carbohydrate fraction from RFF retained structural integrity and almost reached theoretical yields for glucan and xylan. [ABSTRACT FROM AUTHOR]

Highlights • Novel processes for lignin removal from PHL was developed. • The M w of the lignin in PHL increased after HRP treatment. • HRP treatment caused 33.3% dissolved lignin removal at optimized conditions. • Combined treatment of HRP and pDADMAC caused 72.7% dissolved lignin removal. • Combined treatment of HRP and acidification caused 70.3% dissolved lignin removal. Abstract The removal of the lignin from the pre-hydrolysis liquor (PHL) of kraft-based dissolved pulp production is essential for the utilization of the saccharides in PHL. Horseradish peroxidase (HRP) was used to treat the PHL, and the treatment conditions for lignin removal were optimized, and the novel combined processes of HRP treatment and flocculation or acidification for lignin removal were proposed and evaluated. The results showed that the HRP treatment caused 33.3% dissolved lignin and 47.7% turbidity removal at the optimized conditions. The weight average molecular weight of the lignin in PHL increased from 1473 to 1719 g/mol with HRP treatment. The lignin polymerization catalyzed by horseradish peroxidase was of great benefit to the lignin removal in the subsequent processes. Compared to the processes of flocculation with poly diallyl dimethyl ammonium chloride (pDADMAC) or acidification, which caused 35.9% and 24.2% dissolved lignin removal, respectively, the combined process of HRP treatment and pDADMAC treatment or acidification at pH 1.5 caused more than 70% dissolved lignin and nearly completely colloidal lignin removal, accompanied by 12–13% saccharides loss. [ABSTRACT FROM AUTHOR]

Cellulose nanocrystal (CNC) hybrid materials with numerous optical states have great potential as anti-counterfeiting labels and information encryption materials. However, it is challenging to construct multicolor emitting materials with tunable behaviors, which can dramatically enhance anti-counterfeiting abilities. Here, free-standing composite films with vivid multi-structural colors and dual-emitting fluorescence are successfully fabricated through a host-guest coassembly strategy. The lanthanide complex and an aggregation-induced emission molecule (tetraphenylethylene derivative, TPEC) are selected as luminescent guests, which are integrated into the chiral nematic structure of CNCs. The obtained photonic films display broadband reflection across the visible spectrum, which may be attributed to the chiral nematic domains with variations in the helical pitches and helical axis orientations. Under 254 nm excitation, the film exhibits bright red emission, while blue–green emission switching occurs under 365 nm excitation. The broad reflection band of the film covers both the green and red fluorescent emission centers, and right circularly polarized luminescence emission with different dissymmetry factors is produced due to the selective reflection of the left chiral nematic structure. A large glum value up to −0.21 at 600 nm was realized. Additionally, CNC-based materials with tailored shapes are further used in anti-counterfeit tags and decorative applications. [Display omitted] [ABSTRACT FROM AUTHOR]

The removal of colloidal particle and lignin from a pre-hydrolysis liquor (PHL) of biomass is essential for its processing as well as for the value-added utilization of saccharides in the PHL. In this paper, pectinase was used to treat an aspen PHL obtained by pre-hydrolysis at 160 °C, and a novel process in which pectinase treatment was followed by cationic polymer flocculation to enhance colloidal particle and lignin removal was investigated. The results showed that pectinase treatment caused an approximately 50% decrease in the cationic demand of the aspen PHL. For the controlled PHL, approximately 68 mg/L poly-dimethyl diallyl ammonium chloride (pDADMAC) was needed to remove nearly all of the colloidal particles with 40.3% maximum lignin removal; for the enzyme-treated PHL, only approximately 34 mg/L pDADMAC was needed to remove nearly all of the colloidal particles with 43.3% lignin removal. In addition, the enzyme treatment decreased the loss of saccharides during subsequent pDADMAC treatment at the concentration necessary for maximum lignin removal. [ABSTRACT FROM AUTHOR]

To promote the efficient utilization of lignocellulosic materials, one-step fractionation by formic acid-based organosolv process under pressure has been studied for converting lignocellulose in its main components. Lignin and hemicelluloses were selectively dissolved, while cellulose was not obviously degraded. Under optimized conditions (85% formic acid, a liquor-to-solid ratio of 7:1, and a temperature of 145°C for 45 min), this process provided a high efficient way to separate the main components of bamboo, obtaining 42.2% cellulose pulp, 31.5% lignin, 8.5% hemicellulose-rich fraction, 3.56% furfural and 3.80% acetic acid. Cellulose pulp with satisfying viscosity could easily be bleached to a high brightness of over 87% ISO with a short bleaching sequence, and had an acceptable paper strength properties. The recovered lignin fraction contained a small amount of carbohydrates and a considerable part of proteins and p-hydroxycinnamates. Additionally, the organic substances in hemicellulose-rich fraction obtained was composed of 95% carbohydrates, most of which was monosaccharides, as well as 5% lignin. [ABSTRACT FROM AUTHOR]

Bamboo chips were efficiently fractionated using an integrated process of autohydrolysis and formic acid to induce rapid delignification. Autohydrolysis pretreatment facilitated oligosaccharide production, while the subsequent rapid-delignification using formic acid at a low liquid/solid ratio with a relatively short reaction time allowed obtaining cellulose fibers and lignin. The major inter-unit linkages of side-chain in lignin were cleaved during the combined fractionation process. The lignin fraction exhibited higher purity, more phenolic OH groups, less condensed phenolic OH groups, and higher syringyl/guaiacyl ratio (S/G) as compared to MWL and formic acid lignin from the direct formic acid delignification. These results indicate that the combined fractionation process presents a promising approach to the commercial utilization in the biorefinery industry. [ABSTRACT FROM AUTHOR]

Formic acid/water binary solvent extraction with formic acid fraction lower than 77.5% (w/w) of azeotrope was used to extract hemicellulose-derived saccharides from poplar wood at various levels of severity. The highest xylose yield of 77.8% and arabinose yield of 93.5% were obtained at 120 °C and 1 h. To reduce cellulose hydrolysis and facilitate downstream xylose crystallization, mild conditions at 90 °C and 4 h was chosen as optimum severity, which led to the highest xylose fraction of 81.7% in all saccharides extracted, with a remarkable xylose yield of 73.1%. Mass balance analysis showed that 5.84% of xylan was degraded, but only 0.25% of xylan ended up as furfural at optimum severity. The proposed extraction process has high feasibility for industrial application since the low formic acid fraction in solvent allows simple recovery and concentration of used solvent. [ABSTRACT FROM AUTHOR]

Bamboo was fractionated using formic acid based on a one-step organosolv process under high pressure (at 145 °C for 45 min, 0.3 MPa) and at atmospheric pressure (at 101 °C for 120 min), respectively. High-pressure formic acid lignin, atmospheric formic acid lignin and milled wood lignin of bamboo were subjected to comprehensive structural characterization using gel permeation chromatography (GPC), Fourier transform infrared (FTIR) and solution-state NMR techniques ( 1 H, 13 C, 2D-HSQC, and 31 P-NMR spectroscopies). The results indicated that the formic acid fractionation under high pressure presents a quick and efficient delignification method by enhancing the cleavage of interunitary bonds in lignin (β-O-4′, β-β and β-5′), and dissolved lignin also occurred condensation reaction. As compared to atmospheric formic acid lignin, high-pressure formic acid lignin obtained showed higher purity and yield, and had relatively higher contents of phenolic and carboxylic groups. [ABSTRACT FROM AUTHOR]

In this study, the pre-hydrolysis liquor (PHL) was recycled during aspen chip water pre-hydrolysis, and the effects of PHL recycling on the extraction and accumulation of the hemicellulosic saccharides especially that with high molecular weight in the PHL were studied. The results showed that the concentration of hemicellulose saccharides in PHL depended on the pre-hydrolysis temperature and PHL recycling times. Compared to the unrecycled PHL, the concentration of hemicellulosic saccharides in PHL increased significantly when recycling PHL once or twice at 170 °C. Furthermore, the amount of high-molecular-weight hemicelluloses (HMHs) in PHL recycled once at 170 °C increased from 2.58 g/L (unrecycled) to 6.18 g/L, but the corresponding average molecular weight of HMHs decreased from 9.2 kDa to 7.6 kDa. The concentration of hemicellulosic saccharides in PHL decreased with PHL recycling time at 180 °C, accompanied by the formation of a significant amount of furfural. [ABSTRACT FROM AUTHOR]

A novel nanocomposite based on black wattle (BW) tannin and nanocellulose was prepared and applied in heavy metal ions adsorptive removal from aqueous solutions. Firstly, nanocrystalline cellulose was oxidized by sodium periodate to get dialdehyde nanocellulose (DANC). BW tannin was then covalently immobilized onto DANC, which was used as both the matrix and crosslinker, to obtain tannin-nanocellulose (TNCC) composite. The resulting nanocomposite was characterized using FTIR, AFM, and TG. The successful immobilization was confirmed by the chromogenic reaction between FeCl 3 and TNCC and FT-IR analysis. AFM images revealed that TNCC was ellipsoidal particles with lengths ranging from 100–400 nm. Zeta potential measurement showed that TNCC was negative charged at a pH range from 1–12. Compared to the original tannin, the thermal stability of TNCC was slightly increased by the addition of nanocellulose. TNCC demonstrated the maximum adsorption efficiency at pH 2 for Cr(VI) and pH 6 for Cu(II) and Pb(II), respectively. The adsorption for these three metal ions followed pseudo second-order kinetics, indicating the chemisorption nature. The adsorption isotherms all fitted well with the Sips model, and the calculated maximum adsorption capacities were 51.846 mg g −1 , 53.371 mg g −1 and 104.592 mg g −1 for Cu(II), Pb(II) and Cr (VI), respectively. [ABSTRACT FROM AUTHOR]

Solar desalination has been recognized as one of the most promising technologies for solving current freshwater scarcity. However, enhancement of the photothermal conversion efficiency and prohibiting salt crystallization on the top light-absorbing surface are the two major critical challenges for developing highly-efficient and stable solar evaporators. Here, we have discovered that tree roots, often as processing waste when utilizing woods, can serve as a high-efficient solar evaporation device for continuous desalination. The naturally occurring hierarchical structure of tree roots possesses multilevel longitudinal channels from micrometer to millimeter-scale and interconnected porous microstructures, which allows excellent water transport and multidirectional salt exchange, exhibiting a superior anti-salt-accumulation capability even in 21% brine. Together with a mountain-shaped hydrophobic absorber surface obtained from the in situ synthesized Fe 3 O 4 nanoparticles, the designed tree root-based solar evaporator demonstrates an evaporation rate of 1.64 kg m−2 h−1 and ultra-high conversion efficiency of 96% at 1 solar irradiation, rendering it as one of the best performing wood-based solar evaporators. Furthermore, such a high-efficacy, techno-economic and long-term stable seawater desalination platform provided by the architectures of multi-level channel-array in tree root will inspire material scientists and engineers to tailor structurally similar materials from building blocks of broader selections. [Display omitted] • The structural features of tree root make it a "natural choice" for solar evaporation. • Naturally hierarchical structure allows excellent water transport and salt exchange. • Tree root based solar evaporator exhibits superior anti-salt-accumulation property. • A mountain-shaped hydrophobic layer shows extensive and strong light absorption. • An evaporation rate of 1.64 kg m−2 h−1 and conversion efficiency of 96% were obtained. [ABSTRACT FROM AUTHOR]

Pseudo-lignin induced by high-severity dilute acid treatment of lignocellulose has been widely studied because of its detrimental effect on enzymatic hydrolysis. However, cooling-induced pseudo-lignin (CIPL) formed during the cooling process after treatment has always been ignored and never been characterized systematically. To investigate the formation and chemistry of CIPL, liquid hot water treatments of poplar wood were conducted. Samples of treated wood and hydrolysate were taken out from digester at various temperatures during the cooling process for characterization. SEM images evidenced a progressive deposition of CIPL on the surface of the treated wood during cooling process with a yield of 19.6 mg/g treated wood. However, the treated wood which was collected isothermally at reaction temperature showed no pseudo-lignin. Variation of organic compounds in hydrolysate from lignocellulose degradation during cooling process revealed that depolymerized lignin and furfural accounted for 80.4 and 10.6 % of CIPL, respectively, while soluble saccharides from carbohydrate hydrolysis were independent from CIPL formation. These findings stress the importance of isothermal separation of treated wood and hydrolysate. Otherwise, CIPL should hinder enzymatic hydrolysis for biofuels production or delignification for cellulosic fiber production. [ABSTRACT FROM AUTHOR]

[Display omitted] • Poplar was pretreated by reusable organic solvent under mild temperature (≤100 °C). • Almost all hemicelluloses and part of lignin was extracted with cellulose retained. • Sulfonic acid groups were introduced into lignin structure remained in substrates. • 89% improved glucose conversion compared with that of non-sulfonated substance. • New strategy is exploited to realize sulfonation and promote biomass bioconversion. Biomass pretreatment is an essential strategy to overcome biomass recalcitrance and promote lignocellulosic bioconversion. Here, a reusable organic solvent system (formic acid-methanesulfonic acid) was explored to pretreat poplar under a mild temperature (below 100 °C). The results showed that the co-solvent system could extract basically complete hemicelluloses and part of lignin with original cellulose retained in the pretreated substrates. Meanwhile, sulfonic acid groups were introduced into lignin structure remained in the substrates. The glucose conversion yield of the substrates with a higher concentration of sulfonic acid groups (13.2 mmol/kg) reached 45.9 % by reducing the hydrophobic interaction between lignin and cellulase, showing 89.3 % improvement compared with that of the substrates treated with single formic acid. This progressive study aimed to develop a new strategy to realize sulfonation and promote enzymatic hydrolysis of substrates by using mild organic solvent pretreatment. [ABSTRACT FROM AUTHOR]

Prehydrolysis of lignocellulose produces abundant hemicellulose-derived saccharides (HDS). To obtain pure HDS for application in food or pharmaceutical industries, the prehydrolysis liquor (PHL) must be refined to remove non-saccharide compounds (NSC) derived from lignin depolymerization and carbohydrate degradation. In this work, activated carbon (AC) adsorption was employed to purify HDS from NSC with emphasis on adsorption selectivity. The adsorption isotherms showed the priority of NSC to be absorbed over HDS at low AC level. However, increase of AC over 90% of NSC removal made adsorption non-selective due to competitive adsorption between NSC and HDS. Size exclusion chromatography showed that the adsorption of oligomeric HDS was dominant while monomeric HDS was inappreciable. The limited selectivity suggested that AC adsorption is infeasibility for HDS purification, but applicable as a pretreatment method. [ABSTRACT FROM AUTHOR]

A combined process of lime treatment and mixed bed ion exchange was proposed to separate hemicellulose-derived saccharides (HDS) from prehydrolysis liquor (PHL) of lignocellulose as value added products. The optimization of lime treatment achieved up to 44.2% removal of non-saccharide organic compounds (NSOC), mainly colloidal substances, with negligible HDS degradation at 0.5% lime level and subsequent neutralization by phosphoric acid. The residual NSOC and calcium ions in lime-treated PHL were eliminated by mixed bed ion exchange. The breakthrough curves of HDS and NSOC showed selective retention toward NSOC, leading to 75% HDS recovery with 95% purity at 17 bed volumes of exchange capacity. In addition, macroporous resin showed higher exchange capacity than gel resin as indicated by the triple processing volume. The remarkable selectivity of the combined process suggested the feasibility for HDS separation from PHL. [ABSTRACT FROM AUTHOR]

Prehydrolysis of wood biomass prior to kraft cooking provides a stream containing hemicellulose-derived saccharides (HDSs) but also undesired non-saccharide compounds (NSCs) that were resulted from lignin depolymerization and carbohydrate degradation. In this study, a combined process consisting of lime treatment, resin adsorption, and gel filtration was developed to separate HDSs from NSCs. The macro-lignin impurities that accounted for 32.2% of NSCs were removed by lime treatment at 1.2% dosage with negligible HDSs loss. The majority of NSCs, lignin-derived phenolics, were eliminated by mixed bed ion exchange resin, elevating NSCs removal to 94.0%. The remaining NSCs, furfural and hydroxymethylfurfural, were excluded from HDSs by gel filtration. Chemical composition analysis showed that xylooligosaccharides (XOS) with the degree of depolymerization from 2 to 6 accounted for 28% of the total purified HDSs. [ABSTRACT FROM AUTHOR]

The presence of transition metals during the hydrogen peroxide bleaching of pulp results in the decomposition of hydrogen peroxide, which decreases the bleaching efficiency. In this study, chitosans were used as peroxide stabilizer in the alkaline hydrogen peroxide bleaching of aspen chemithermomechanical pulp (CTMP). The results showed that the brightness of the bleached CTMP increased 1.5% ISO by addition of 0.1% chitosan with 95% degree of deacetylation during peroxide bleaching. Transition metals in the form of ions or metal colloid particles, such as iron, copper and manganese, could be adsorbed by chitosans. Chitosans could inhibit the decomposition of hydrogen peroxide catalyzed by different transition metals under alkaline conditions. The ability of chitosans to inhibit peroxide decomposition depended on the type of transition metals, chitosan concentration and degree of deacetylation applied. The addition of chitosan slightly reduced the concentration of the hydroxyl radical formed during the hydrogen peroxide bleaching of aspen CTMP. [ABSTRACT FROM AUTHOR]

Aerogels with chiral nematic structure are promising candidates for structural coatings and optical devices. Cellulose nanocrystals (CNCs) are excellent photonic building blocks for the fabrication of chiral nematic aerogels. Conventional bottom-up fabrication process usually is complicated, energy and time consumption. Herein, a simple method for fabricating CNCs and polyethylene glycol (PEG) based foams with chiral nematic structure was proposed. After CNCs-PEG based solid films were swollen with N-methylmorpholine N-oxide (NMMO) aqueous solutions, the obtained hydrogels were freeze-dried, resulting in chiral nematic foams. During the process, both macropores and mesopores were created with chiral nematic phase retained inside foam walls. Owning numerous macropores and chiral nematic walls of varying axial directions, the chiral nematic foams exhibited a broad-band reflection phenomenon. Moreover, the representative Titanium diisopropoxide(bis-2,4-pentanedionate) was permeated into foam walls, and transformed into chiral nematic TiO 2 foams after annealing. We envisage that the chiral nematic foams may have a promising application in the fields of chiral separation or chiral catalysis. A simple method is proposed to fabricate CNC-based foams with chiral nematic structure. CNC-based films are first swollen with a good solvent of cellulose. Then swollen CNC films are freeze-dried. The resultant chiral nematic foams exhibit a wide-band reflection phenomenon. Chiral nematic TiO 2 foams can be constructed by using CNC-based foams as a template. [Display omitted] • A simple method is proposed to fabricate cellulose nanocrystals (CNCs)-based foams with chiral nematic structure. • The obtained chiral nematic foams exhibit a wide-band reflection phenomenon. • Chiral nematic TiO 2 foams can be constructed by using CNCs-based foams as a template. [ABSTRACT FROM AUTHOR]

Chiral nematic papers (CNPs) with mesopores structure based on cellulose nanocrystals (CNCs) were fabricated successfully via a swelling and freeze-drying method. The order of the original chiral nematic cellulose nanocrystals film was preserved in CNPs, which was proved by scanning electron microscopy (SEM), polarized optical microscopy (POM) measurements and circular dichroism (CD) spectra. The CNPs exhibited excellent optical responsive properties to different solvents. Inspired by this feature, a colorable ink containing amounts of gel particles was prepared by pulverizing CNPs/water mixture into a suspension. Patterns written in suspension ink with various colors can be formed when soaked with different solvents. Moreover, CNPs displayed an irreversible color response to compression. Additionally, the hydrophilicity of CNPs was tuned by polyethyleneimine. Modified CNPs exhibited different colors under the identical solvent environment when compared to the original one. Aqueous PEI can be used as an ink to depict responsive photonic patterns on CNPs. Iridescent chiral nematic papers (CNPs) with mesopores structure exhibit excellent optical responsive properties to mixed solvents. Modified CNPs with polyethylene imine (PEI) display different colors under the identical solvent environment when compared to the original one. Aqueous PEI can be used as an ink to depict responsive photonic patterns on CNPs. [Display omitted] [ABSTRACT FROM AUTHOR]

Saccharides and lignin components in prehydrolysis liquor (PHL) from kraft-based dissolving pulp production was characterized after being fractionated using membrane filtration. The results showed that the membrane filtration provided a method for organics fractionation with considerable recovery rate, but exhibited some disadvantages. Besides the limited ability in purifying oligosaccharides (OS) due to the overlaps of molecular weight distribution with lignin components, the membrane filtration could not improve the homogeneity of OS as indicated by the analysis of chemical compositions and the degree of polymerization (DP), which may be ascribed to the linear conformation of OS. The characterization of lignin components indicated a great potential for polymer industry because of the remarkable content of phenolic hydroxyl groups (PhOH), especially for low molecular weight (LMW) fraction. It was concluded the organics in PHL provided streams of value-added chemicals. However, the practical significance thereof can be realized and maximized only when they are successfully and completely fractionated. [ABSTRACT FROM AUTHOR]

Based on the formation of cellulose hydrogels in NaOH/urea aqueous solvent media, cellulose self-assembly precursor is acquired. It is proved that the water uptake capability of the cellulose hydrogels depends highly on the cross-link degree (CLD) of cellulose. With varying CLD and concentration of cellulose, a variety of morphologies of cellulose self-assemblies, including sheets with perfect morphology, high-aspect-ratio fibers, and disorganized segments and network, are formed through evaporation. Furthermore, cellulose films are fabricated by diecasting and evaporating the cellulose hydrogels, resulting in a 3D-ordered structure of closely stacking of cellulose sheets. The mechanical test indicates both tensile strength and flexibility of the cellulose films are greatly improved, which is attributed to the formation of the orderly stacking of cellulose sheets. The study is expected to lay an important foundation on the preparation of ordered and high-strength cellulose materials. [ABSTRACT FROM AUTHOR]

The effects of recycling on the microstructure and properties of bleached aspen chemithermomechanical pulp (CTMP) fibres were systematically investigated. The low-temperature nitrogen adsorption and atomic force microscopy results showed that a substantial amount of large pores and most of the very small pores in the fibre wall closed and the fibre surface became less coarse and porous during recycling. The partial cocrystallisation of cellulose microfibrils took place, as reflected in the increment of the cellulose crystallinity and the width of the crystallite in the 0 0 2 lattice plane. These irreversible structural changes caused significant hornification of the recycled fibres, leading to the loss of swelling and bonding capability. The decrease of the tensile index, burst index, and tear index further demonstrated the deterioration of the fibre properties. However, the single-fibre strength considerably increased after recycling, which was mainly due to the enlarged cellulose aggregates in the fibre wall. [ABSTRACT FROM AUTHOR]

The specific elimination of lignin derivatives from wood hydrolysate without sugar loss has great practical significance to biorefinery and bioenergy. In the present study, a process consisting of calcium hydroxide and anion exchange resin treatments was developed for the purpose of selective removal of lignin from wood prehydrolysis liquor (PHL). Particular emphasis was made on the ionization of phenolic lignin, and the subsequent binding to metallic salts. It was observed that phenolic hydroxyl groups (PhOH) in lignin played an important role in lignin removal. The results showed that up to 95.2% lignin was removed from PHL with 78.8% sugar recovery. This suggested that the proposed process is highly specific to lignin, and therefore can be envisaged as a great contribution to wood-sugar production or bioenergy conversion. [ABSTRACT FROM AUTHOR]

Highlights: [•] We studied the effects of acetone/water mixture coagulants on the properties of RC films. [•] The films from φ of 2.0 showed excellent dimensional stability and film-forming ability. [•] Small ions could be encapsulated and slowly released from the RC films. [ • ] The microstructure of the films changed greatly with varying φ. [ABSTRACT FROM AUTHOR]