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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]

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]

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]

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]

Herein, a great potential approach initiated by laccase is applied to graft the biopolymers (chitosan and phenols) onto the unbleached Kraft pulp fibers to enhance the hydrophobicity and strength. The results showed that the chitosan and laccase/phenols exhibited a synergistic action on the significant improvement of the hydrophobicity of the KP pulp fibers. Compared with the base paper, a high sizing degree value (227.08 s) was achieved when the fibers were treated by the laccase/4-hexyloxyphenol/chitosan (Lac/HP/CTS) system. The water retention value of the corresponding KP fibers reduced from 176.8 to 171.3%, and the Kappa number of treated fibers increased from 26.8 to 29.3, confirming the successful graft of HP onto the fibers. The effect of the reaction parameters, including the temperature, pH, HP and chitosan dosage, reaction time and pulp suspension consistency on the strength and hydrophobicity was investigated. pH value was found as the most remarkable factor influencing the sizing degree and gave a highest sizing value (506.2 s) at pH 5.5. The strength performance presented an opposite trend against the hydrophobicity, since the number of formed hydrogen bonds is the least when the hydrophobicity is the best. This work is extremely significant for providing valuable reference on improving the hydrophobicity and strength performance of papers through a green and biological way. [ABSTRACT FROM AUTHOR]

In order to evaluate reservoir characteristics and gas potential of organic-rich shale in Bottom-Lower Cambrian Hetang Formation and Upper Ordovician Xinkailing Formation, Xiuwu Basin, Jiangxi Province, Lower Yangtze Plate of China, researches regarding reservoir characteristics of organic-rich shale thickness, moderate burial depth, abundance and maturity of organic matter, fracturability, organic-matter pores and absorption performance have been conducted to Hetang Formation and Xinkailing Formation through field survey, shallow drilling, analysis to hydrocarbon-generation potential, scanning electron microscopy, measuring specific surface area and isothermal adsorption experiments. The results show that (1) Hetang Formation reservoir, although with extremely rich material basis, is of unfavorable hydrocarbon generation conditions due to late-stage thermal maturity, besides of undeveloped micropore structure, reservoir space development mainly by macroscopic crack, so further exploration should focus on locating favorable areas of low maturity and developed cracks, which is considered distributing in the core of Yanshan-Lingangshan-Shiziyan Mountains syncline; (2) Xinkailing Formation reservoir is of better organic matter abundance, pore development and absorption performance than Xinkailing Formation and hence further exploration should focus on surveying favorable areas of better sedimentary facies belt and stable structure for major breakthrough in shale-gas exploration, which is considered distributing in Wuning-Lixi and Jinkou-Tuolin areas. [ABSTRACT FROM AUTHOR]

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]

Artificial antioxidants are synthesized from fossil sources and are now widely used in the polymer, food, and cosmetics industries. The gradual depletion of fossil resources makes it practically significant and necessary to produce green antioxidants from renewable lignocellulosic resources. Herein, short‐time hydrothermal (STH) treatment was developed for production of lignin‐derived polyphenol antioxidants (LPAs) from poplar wood under conditions of high temperature and high pressure. LPA yields from 21.5 to 37.6 % on the basis of lignin in untreated wood were obtained by STH treatments as result of lignin depolymerization at 190–200 °C and 10 MPa in 5–8 min. Depolymerization reactions were confirmed by the much lower molecular weight of LPA (1076 g mol−1) than that of native lignin (4094 g mol−1). NMR spectroscopy revealed the structural features of lignin in the isolated LPA, namely syringyl and guaiacyl units with well‐preserved interunit linkages. A Folin–Ciocalteu assay indicated that each LPA molecule contained 5.4 phenolic hydroxyl groups on average, much more than other technical lignins. The remarkable antioxidant ability of LPA was verified by the radical‐scavenging index of 53.5–67.3, much higher than 0.2–11.1 of the commercial antioxidants butylated hydroxytoluene (BHT) and butylated hydroxyanisole (BHA). STH treatment only requires water and heat for production of high‐value antioxidant, which provides a green and sustainable method for the utilization of lignocelluloses. [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]

Whole valorization of carbohydrate and lignin from biomass was achieved by rapid flow‐through fractionation (RFF) within 15 min. Wheat straw was effectively deconstructed into its principle components without degradation by using easily recyclable aqueous formic acid (72 wt %) at 130 °C. The obtained cellulose‐rich solid showed a nearly complete glucan recovery and 73.8 % glucose conversion after enzymatic hydrolysis. Xylan also reached full recovery with negligible furfural formation with a sum of 80 % of oligo/mono xylose in spent liquor and 20 % of xylan remaining in the solid. Up to 75.4 % lignin was dissolved in the spent liquor and further fractionated into water‐insoluble (WIL) and water‐soluble lignin (WSL) by dilution with water. WIL showed a non‐condensed and well‐preserved structure with 84.5 % β‐O‐4 remaining, which is believed to be beneficial for catalytic conversion into low‐molecular‐weight chemicals and fuels. The concentration of employed formic acid was below the formic acid/water azeotrope, and therefore the reaction medium could be restored through simple distillation. Together with the joint valorization of lignin and carbohydrates, the presented RFF is a promising process for sustainable biorefinery. Whole valorization of carbohydrate and lignin from biomass is achieved by rapid flow‐through fractionation within 15 min. Wheat straw is effectively deconstructed into its principle components without degradation by using easily recyclable aqueous formic acid (72 wt %) at 130 °C. The obtained cellulose‐rich solid shows a nearly complete glucan recovery and 73.8 % glucose conversion after enzymatic hydrolysis. [ABSTRACT FROM AUTHOR]

Abstract: Development of a reliable and rapid process for synthesis of stable silver nanoparticles using nanocellulose is highly desired. In the present study, we report an efficient approach for the synthesis of stable silver nanoparticles (AgNPs) using dialdehyde cellulose nanocrystal (DACNC) as both reducing and stabilizing agent. The periodated cellulose nanocrystals (CNCs) were able to reduce silver ions to obtain cellulose nanocrystal-AgNPs (CNC-AgNPs) composites with high Ag percentage. The resulting composites were characterized by using UV-Vis spectroscopy, fourier infrared spectroscopy (FT-IR), X-ray diffraction (XRD), atomic absorption spectroscopy (AAS), thermogravimetric analysis (TGA) and transmission electron microscopy (TEM). Furthermore, their antimicrobial activities were investigated. The formation of AgNPs was evidenced by the surface plasmon resonance peak at around 400 nm. XRD data showed diffraction peaks at 2θ 38.33º, 44.55º, 64.27º, 77.66º, which can be indexed to (111), (200), (220), (311), and (222) planes of pure silver, indicating the successful synthesis of silver nanoparticles. The TEM images of CNC-AgNPs showed spherical AgNPs with sizes from several nanometers to 30 nm on the cellulose nanocrystal surfaces. The composites showed high antibacterial activities against Escherichia coli and Staphylococcus aureus. When the CNC-AgNPs was added into the pulp fibers, the obtained handsheets also displayed strong antibacterial activities with higher strength properties and a lower air permeability, indicating potential applications in food packaging materials.Graphical abstract: [ABSTRACT FROM AUTHOR]

We report the preparation of flexible latex/graphene oxide (GO) composite films templated by cellulose nanocrystals (CNCs), which show dual responses with interesting color and morphological changes toward water. First, ternary composite films with chiral nematic order were prepared via evaporation-induced self-assembly (EISA) of an aqueous dispersion containing latex, GO and CNCs. Driven by the difference in gravity and the increase of entropy, uneven distribution of GO occurs with the majority gathering at the top of the film. In the second step, CNCs were selectively etched by alkali treatment, leading to the formation of latex/GO (LG) composite films which retain the chiral nematic order and the asymmetric distribution of GO. Meanwhile, the flexibility of the film has been greatly improved. The asymmetrically-organized LG film has different wettability on the top and bottom surfaces, which induces varying extent of swelling toward water. As a result, the synchronous response of color and actuation was realized. Compared to other two-dimensional actuators, the LG films presented in this work have the advantage of easy preparation and additional color change. In addition, the films are also more robust than those with a bilayer structure, which tend to delaminate during repeated utilization. [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]

Fabrication of nanostructures with multiple functions templated by cellulose nanocrystals (CNCs) has become very attractive, and chiral structures fabricated via evaporation-induced self-assembly (EISA) have become particularly important for building photonic films. However, films obtained so far suffer from low mechanical strength, which significantly hinders their applications. Here, we report a facile way to obtain highly flexible latex films with tunable structural colors via CNC templating. First, composite films (CFs) containing silicone-modified acrylic latexes (SALs) and CNCs were prepared via EISA. At mixing ratios of SALs to CNCs of 0.2–0.4, homogenous films were obtained, where the latexes cohere together to form a network. After alkali treatment followed by rinsing with water or alcohol, CNCs could be removed, leading to the formation of free-standing latex films. The chiral nematic (N*) structure originating from the organization of CNCs via EISA was retained in the latex film, leading to the preservation of the structural color. Due to a reduced helical pitch caused by the deformation of the porous latex network during the removal of CNCs and the subsequent drying process, the reflection of the film could be blue shifted, and the extent was closely related to the type of solvent used during rinsing. Interestingly, the structural color of the latex film could be reversibly tuned by water adsorption and dehydration, which could be ascribed to the expansion/shrinking of the porous latex network. The flexibility of the pores in expansion/shrinking also effectively released the internal stress of the film when it was stretched and/or deformed. This feature, combined with the intrinsic flexibility of the backbones formed by the crosslinking of SALs, imparts the film impressive mechanical strength. The maximum elongation at break reached 34.5%, ∼8 times larger than that of the best film reported so far. [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]

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]