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Composite polymer electrolyte (CPE) films with high room temperature ionic conductivity are urgently needed for the practical application of high-safety solid-state batteries (SSBs). Here, a flexible polymer-polymer CPE thin film reinforced by a three-dimensional (3D) bacterial cellulose (BC) framework derived from natural BC hydrogel was prepared via the in situ photo-polymerization method. The BC film was utilized as the supporting matrix to ensure high flexibility and mechanical strength. The BC-CPE attained a high room temperature ionic conductivity of 1.3 × 10 -4 S cm -1 . The Li∣BC-CPE∣Li symmetric cell manifested stable cycles of more than 1200 h. The LCO∣BC-CPE∣Li full cell attained an initial discharge specific capacity of 128.7 mAh g -1 with 82.6% discharge capacity retention after 150 cycles at 0.2 C under room temperature. The proposed polymer-polymer CPE configuration represents a promising route for manufacturing environmental SSBs, especially since cellulose biomaterials are abundant in nature., (© 2022 IOP Publishing Ltd.)

The valorization of cellulose and lignin residues in an integrated biorefinery is of great significance to improve the overall economics but has been challenged by their structural recalcitrance, especially for lignin residue. In this work, a facile chemical conversion route to fabricating functional UV-blocking cellulose/lignin composite films through a facile dissolution-regeneration process using these biomass residues was proposed. Three representative lignin residues, i.e., aspen and poplar wood lignin, and corn stover (CS) lignin were assessed for their feasibility for the film fabrication. The UV-blocking performance of the composite films were comparatively investigated. Results showed that all these three lignin residues could enhance the UV-blocking property of the composite films, corresponding to the reduction in the optical energy band gap from 4.31 to 3.72 eV, while poplar lignin had a considerable content of chromophores and showed the best UV-blocking enhancement among these three assessing lignins. The enhancement of UV-blocking property was achieved without compromising the visible-light transparency, mechanical strength and thermal stability of the composite films even at 4% lignin loading. This work showed the high promise of integrating biomass residue conversion into lignocellulose biorefinery for a multi-production purpose.

In practical applications, the full biodegradability of all-biomass-based bacterial cellulose (BC) composites enhances their environmentally friendliness but results in the poor durability especially at humid conditions. This work prepared BC/lignin nanoparticles (LNPs) composite films with retarded biodegradability, which could broaden their application area. Three LNPs were fabricated using technical lignins extracted by deep eutectic solvent (DES), ethanol organosolv, soda/anthraquinone from poplar. LNPs involvement during BC fermentation showed limited influence on its productivity but significantly retarded the biodegradation of composite films. The potential inhibition mechanism was physical barrier and non-productive binding of LNPs. The BC/Soda LNPs showed much higher retarded degradation property (~58 wt% degradation) compared to BC/Organosolv LNPs and BC/DES LNPs (~85 wt% and ~ 97 wt% degradation respectively) at high enzyme loadings of 5 mg g -1  BCE. While at low enzyme loadings of 1 mg g -1  BCE, all these three composite films showed comparable retarded degradation property of ~60 wt%., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

This work tailored a promising two-step pretreatment, i.e., liquid hot water extraction followed by mild acidic deep eutectic solvents pretreatment for clean lignocellulose fractionation while enhancing cellulose reactivity for its subsequent utilization. The abilities of three acidic deep eutectic solvents (formic acid-, acetic acid- and lactic acid-choline chloride) to selectively extract poplar wood lignin and enhance cellulose reactivity were comparatively assessed. Results showed that rather high lignin selectivity of 6.3-7.9 was obtained while the available area and porosity of the resulting cellulose were significantly increased. The resulting cellulose pulps exhibited comparable chemical reactivity to commercial bleached Kraft pulp when cellulose acetate was selected as testing cellulose derivative for demonstrating purpose, showing their great promise for high-value use. It was proposed that the unique ionic properties of these acidic deep eutectic solvents were responsible for their selective lignin removal and cellulose swelling/deconstruction to enhance cellulose chemical reactivity., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Upgrading renewable cellulose biopolymer to various high-value material/chemical is of great importance in building a sustainable bio-economy. This work assessed the technical feasibility of fabricating transparent cellulose/xylan composite films using facile solution-casting method. More importantly, this work also initially assessed the technical potential of xylanase treatment to selectively modify the surface of the obtained composite films with the goal of extending their applications. When bleached Kraft xylan addition was lower than 20 wt%, the composite films could still retain their original mechanical and structural advantages. Xylanase treatment specifically removed 26.0% and 32.3% xylan of the composite films with an enzyme loading of 2 and 5 mg g -1 cellulose, respectively. It was shown that xylan component was heterogeneously located in the surface of the composite films during film-casting process, which allowed the subsequent surface etching/roughing at nanoscale using facile xylanase treatment without compromising their structural advantages., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Wheat straw was pretreated by phosphoric acid plus hydrogen peroxide (PHP), in which temperature, time, and H 3 PO 4 proportion for pretreatment were investigated by using response surface method. Results indicated that hemicellulose and lignin removal positively responded to the increase of pretreatment temperature, H 3 PO 4 proportion, and time. H 3 PO 4 proportion was the most important variable to control cellulose recovery, followed by pretreatment temperature and time. Moreover, these three variables all negatively related to cellulose recovery. Increasing H 3 PO 4 proportion can improve enzymatic hydrolysis; however, reduction on cellulose recovery results in decrease of glucose yield. Extra high temperature or long time for pretreatment was not beneficial to enzymatic hydrolysis and glucose yield. Based on the criterion for minimizing H 3 PO 4 usage and maximizing glucose yield, the optimized pretreatment conditions was 40 °C, 2.0 h, and H 3 PO 4 proportion of 70.2 % (H 2 O 2 proportion of 5.2 %), by which glucose yielded 299 mg/g wheat straw (946.2 mg/g cellulose) after 72-h enzymatic hydrolysis.

Steam-pretreated sweet sorghum bagasse (SSB) and Douglas-fir (DF) were employed for SHF and SSF to evaluate the effects of xylanase supplementation and delignification on ethanol production. Results indicated final ethanol concentration in SHF could reach 28.4 g/L (SSB) and 20.4 g/L (DF) by xylanase supplementation with the increase of 46% and 61% in comparison with controls. The delignification could significantly enhance final ethanol concentration to 31.2g/L (SSB) and 30.2 g/L (DF) with the increase of 61% and 138%. In SSF, final ethanol concentration in the delignified SSB and DF arrived at 27.6 g/L and 34.3 g/L with the increase of 26% and 157% compared with controls. However, only 2.2 g/L (SSB) and 6.9 g/L (DF) ethanol were obtained with xylanase supplementation. According to these results, it could be concluded that delignification was beneficial to improve ethanol production of SHF and SSF. The xylanase supplementation (0.12 g protein/g glucan) was only positive to SHF while retarded SSF seriously., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

The preparation methods for refining kraft pulp into dissolving pulp are generally limited by an aggressive chemical input and overlook the valorization of the xylan component. This work demonstrated an integrated process involving deep eutectic solvent (DES) pretreatment followed by mechanical refining and enzymatic hydrolysis (DME) for the preparation of the dissolving pulp and co-production of two xylo-oligosaccharides (XOSs). The technical feasibility of the DME process was assessed with typical bleached bamboo and poplar kraft pulp. It was shown that the employed aqueous alkaline DES consisting of choline hydroxide and urea (40% concentration) could initially purify cellulose while selectively extracting alkali-soluble XOSs by the unique bonding behavior of the DES. The resulting dissolving pulp showed considerably high cellulose contents of 94.3% and 91.1% for the bleached bamboo pulp and bleached poplar pulp, respectively. The overall cascade process significantly improved the cellulose reactivity and quality (α-cellulose > 90%, S10/S18 < 8%), which could meet the high criterion for commercial dissolving pulp while extracting 69.4% of the content of high-purity XOSs. When 100 g bleached pulp was subjected to this technology route, a high yield of over 80 g cellulose was obtained for both the substrates while simultaneously producing the alkaline and water-soluble XOSs (approximately 10 g). It was proposed that the strong hydrogen-bonding-accepting ability of the ChOH-urea DES system could purify cellulose through XOS selective solubilization while swelling cellulose to ease the subsequent mechanical fibrillation. Subsequently, the mechanically treated cellulose with enhanced accessibility to xylanase provided an additional technique for further cellulose purification through a facile enzymatic hydrolysis. Therefore, this proposed integrated technique could refine bleached kraft pulp into dissolving pulp with enhanced cellulose reactivity while co-producing high-purity XOS product streams. [ABSTRACT FROM AUTHOR]

The conventional endo–exo synergism model has extensively been supported in literature, which is based on the perception that endoglucanases (EGs) expose or create accessible sites on the cellulose chain to facilitate the action of processive cellobiohydrolases (CBHs). However, there is a lack of information on why some bacterial and fungal CBHs and EGs do not exhibit synergism. Therefore, the present study evaluated and compared the synergistic relationships between cellulases from different microbial sources and provided insights into how different GH families govern synergism. The results showed that CmixA2 (a mixture of TlCel7A and CtCel5A) displayed the highest effect with BaCel5A (degree of synergy for reducing sugars and glucose of 1.47 and 1.41, respectively) in a protein mass ratio of 75–25%. No synergism was detected between CmixB1/B2 (as well as CmixC1/C2) and any of the EGs, and the combinations did not improve the overall cellulose hydrolysis. These findings further support the hypothesis that "not all endo-to exo-cellulase interactions are synergistic", and that the extent of synergism is dependent on the composition of cellulase systems from various sources and their compatibility in the cellulase cocktail. This method of screening for maximal compatibility between exo- and endo-cellulases constitutes a critical step towards the design of improved synergistic cellulose-degrading cocktails for industrial-scale biomass degradation. [ABSTRACT FROM AUTHOR]

To obtain high yield and high concentration glucose from corncob residues (CRs), tetrahydrofuran (THF) + H 2 O co-solvent pretreatment was employed. The pretreatment parameters were firstly optimized by Box-Behnken Design of response surface method, and the maximum glucose yield (498.2 mg/g CRs) was obtained via enzymatic hydrolysis after pretreated under optimized conditions (53.7% THF concentration, 202.3 °C, 1.05 h). Then, the pretreated CRs under optimized conditions (optimized-CRs) were enzymatically hydrolyzed at high solid loading (15%–20%) and low enzyme input (5–8 FPU/g cellulose). The high concentration glucose production (128.6 mg/mL) was obtained from optimized-CRs after enzymatic hydrolysis at 20% solid loading with 10 FPU/g cellulose for 72 h, and then showed potential for reduction of enzyme input. Finally, the interactions between the 9 substrate-related factors and cellulose conversion were analyzed through correlation analysis, and found that Klason lignin remained in the cellulose-rich fractions and pseudo lignin condensed on the surface of the recovered substrate were the predominant inhibitors for enzymatic hydrolysis. • The THF + H 2 O co-solvent pretreatments of CRs were optimized by BBD of RSM. • Maximum glucose yield (498.2 mg/g CRs) obtained under optimized conditions. • 128.6 mg/mL glucose titer was gained at 20% solid loading with 10 FPU/g cellulose. • KL remained in substrate hindered cellulose utilization through steric hindrance. • Pseudo lignin condensed on the surface of substrate decreased enzyme activity. [ABSTRACT FROM AUTHOR]

Effective valorization of lignin is crucial to achieve a sustainable, economic and competitive biorefinery of lignocellulosic biomass. In this work, an integrated process was proposed based on a concentrated phosphoric acid plus hydrogen peroxide (PHP) pretreatment to simultaneously facilitate cellulose digestibility and modify lignin as adsorbent. As a dominant constitutor of PHP pretreatment, H2O2 input and its influence on the overall fractionation/lignin modification performance was thoroughly investigated. Results indicated that wheat straw was fractionated more efficiently by increasing the H2O2 input. H2O2 input had a significant influence on the digestibility of the obtained cellulose-rich fraction whereby almost 100.0% cellulose-glucose conversion can be achieved even with only 0.88% H2O2 input. Besides, the adsorption capacity of lignin on MB was improved (74.3 to 210.1 mg g−1) due to the oxidative-modification in PHP pretreatment with H2O2 inputs. Regression analysis indicated that –COOH groups mainly governed the lignin adsorption (R2 = 0.946), which displayed the considerable adsorption capacities for typical cationic substances. This work shows a promising way to integrate the lignin modification concept into the emerging PHP pretreatment process with the dual goal of both cellulose utilization and lignin valorization. [ABSTRACT FROM AUTHOR]

Although recent work has shown natural lignin products are promising to fabricate various polymer based functional composites, high-value applications were challenged by their structural complexity and inhomogeneity. This work specially assessed the potential of four technical lignins for cellulose based functional films production. These four technical lignins were obtained by emerging pretreatment systems, i.e., lactic acid-betaine deep eutectic solvent (DES), ethanol organosolv, soda/anthraquinone (Soda/AQ) and the sodium salicylate hydrotrope, and their phenolic substructures were comparatively identified by prevalent 31P NMR technique. The influence of lignin chemical structure on the antioxidant potential and UV-shielding performance of the prepared cellulose/technical lignin composite films were assessed. Results showed severe organosolv and soda/AQ pretreatment produced technical lignins with higher total phenolic hydroxyl groups (3.37 and 3.23 mmol g-1 respectively), which also exhibited higher antioxidant activities. The composite films could effectively block the ultraviolet lights especially for UVB region (ultraviolet B, 280–315 nm) at only 5 wt.% lignin content. The contribution of lignin phenolic substructures to both antioxidant activity and UV-shielding property from high to low was syringyl > guaiacyl > p-hydroxyphenyl phenolic hydroxyl groups. This work provided some useful information that could facilitate upstream lignin extraction or downstream value-added applications. [ABSTRACT FROM AUTHOR]

• Bacterial cellulose (BC) is an ideal precursor for material processing. • The whole crop of sweet sorghum was attempted to utilize for BC production. • The lignocellulosic parts have better BC yield in 6-day static incubation. • BC obtained from various parts of sweet sorghum owns stable quality. • Utilizing the sweet sorghum as a "material crop" for material building blocks. In this work, the whole biomass of sweet sorghum [ Sorghum bicolor (L.) Moench ], including the sugar-rich juice and lignocellulosic parts (root, stalk, and leaf), was individually investigated as carbon sources for bacterial cellulose (BC) production. The juice part was employed directly, and the lignocellulosic parts were pretreated by PHP (phosphoric acid plus hydrogen peroxide) to yield the fermentable sugar for BC production. Results indicated that the BC yield from the root (2.28 g/L), stalk (1.82 g/L), and leaf (2.54 g/L) was 1.86–2.59-fold higher than the commercial d -glucose medium (0.98 g/L), and a comparable BC yield (0.87 g/L) also can be obtained from the juice. The structural properties of BC from the lignocellulosic parts were similar to those from the d -glucose medium. The tensile strength of BC obtained from the stalk and leaf was 8.24 MPa and 4.83 MPa, respectively, which was superior to that of the glucose medium (2.07 MPa). Considering the huge biomass yield of sweet sorghum, the present work broadens the "energy crop" sweet sorghum as a "material crop" towards a new biorefinery concept for material building blocks. [ABSTRACT FROM AUTHOR]

Lignin-carbohydrate complexes (LCC) that exhibit both structural advantages of lignin and carbohydrates are promising amphiphilic biopolymers, but the extraction is challenged by its liable chemical bond cleavage between lignin and carbohydrates. This work proposed a facile chemical route to integrating the production of water-insoluble (WIS LCC) and water-soluble LCC (WS LCC) into the emerging deep eutectic solvent (DES) biorefinery at mild conditions. The tailored mechanochemical fractionation process of ball milling assisted aqueous alkaline DES could extract 24.2 % LCC in total, with the co-production of a highly hydrolysable cellulose fraction (98.7 % glucose conversion). The resulting LCC exhibited considerably high contents of β-O-4, phenyl glycoside, and ferulic acid linkage bonds. When 100 g starting straw was subjected to this technique route, 9.1 g WIS LCC, 15.1 g WS LCC and 45.5 g glucose were cascaded produced. It was proposed that the selective disruption of hydrogen bonding entangled network and the quasi-state dissolution of the whole biomass allowed the subsequent cascade fractionation of WIS LCC, WS LCC and highly hydrolysable cellulose through solution property adjustment. This work showed a promising approach for LCC production with high yield without compromising cellulose conversion potential, which has been challenging in the current lignocellulose biorefinery. [Display omitted] [ABSTRACT FROM AUTHOR]

• Hydrophobic aluminate coupling agent was used to protect the underlying cellulose nanofibers layer. • The strong interaction between the layers of coatings made a stable superhydrophilic/air superoleophobic interface. • The modified CM could maintain superhydrophilic and air superoleophobic at various temperatures, pH values, and abrasion. • It has high flux and separation efficiency in the continuous separation process. • The modified superhydrophilic/air superoleophobic interface could separate the oil-water mixture without pre-wetting. Oily wastewater and oil spill have always been a common concern of environmental problems, and superwetting materials are the key to oil-water separation. However, the superwetting material is constantly blocked by oil, which is a crucial obstacle to its practical application. In this study, we proposed a novel strategy to protect the underlying superhydrophilic layer by using a hydrophobic aluminate coupling agent. And we constructed the superhydrophilic layer with cellulose and the superoleophobic surface with FS50-modified rough nanoparticles. Porous ceramics could achieve stable superhydrophilic/air superoleophobic properties through a simple soaking step (modified CM). The advanced and receding contact angles on the modified CM surface were 151.74° and 149.11° for crude oil. The modified CM could maintain the contact angle of oil above 150° at various temperatures, pH values, and abrasion. In the continuous separation process, the flux remained above 1.4 × 104 L m−2 h−1, and the separation efficiency could achieve above 99 % for soybean oil. Besides, the modified CM could also separate oil-in-water emulsion. Further, we proposed the coexistence and fabrication mechanism of superhydrophilic/air superoleophobic interface. This study provides new design ideas for developing durable oil-water separation materials. [ABSTRACT FROM AUTHOR]

Cascade utilization of crop straw through a FeCl 3 -mediated deep eutectic solvent biorefinery: lignin-containing cellulose nanofibers flocculant fabrication followed by fertilizer production. [Display omitted] • FeCl 3 -mediated deep eutectic solvent pretreatment was proposed. • Cascade utilization of crop straw residue in farmland ecosystem was investigated. • Surface lignin enhanced iron oxide immobilization for phosphorus removal. • Nearly complete phosphorus removal was achieved using Fe-LCNFs. The current agriculture relies heavily on the input of fossil resource-based chemicals while continuously generating crop straw residue and phosphorus-containing farmland drainage, which has been a serious threat to its sustainable development. This work proposed a closed-loop technique route to cascade utilization of crop straw residue through lignin-containing cellulose nanofibers (LCNFs) flocculant fabrication followed by fertilizer production, with the goal of farmland drainage phosphorus recovery and reuse. The technical feasibility of FeCl 3 -mediated deep eutectic solvents (DES) processing of wheat and rice straw into iron oxide immobilized LCNFs (Fe-LCNFs) flocculant, the flocculation performance of total phosphorus for representative farmland drainage, and the potential for co-production of glucose and phosphorus-containing fertilizer were comprehensively assessed. Results showed that the FeCl 3 incorporation significantly enhanced the deconstruction and fractionation ability of DESs, resulting in nearly 100% hemicellulose removal and 86.4% delignification. The prepared Fe-LCNFs flocculant exhibited efficient total phosphorus removal of 99.9%. The spent flocs exhibited considerable glucose conversion of ∼52.4% even with iron oxide and phosphorus complex. It was calculated that 8.6 g reactive lignin, 27.9 g phosphorus-containing fertilizer and 30.7 g glucose additive for foliar fertilizer could be mostly obtained using this integrated technique. It was proposed that the dual function of biomass deconstruction and lignin fragmentation/relocation of the employed FeCl 3 -mediated DESs showed a determined role in enhancing the flocculation performance of Fe-LCNFs and enzymatic hydrolysis efficiency of the spent flocs. This work showed a chemical engineering approach for cascade and closed-loop utilization of crop straw toward more sustainable and green agriculture application. [ABSTRACT FROM AUTHOR]