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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]

The hardwood bleached kraft pulp (HBKP) fibers were pretreated by PFI mill to obtain the substrates, the effects of fibrillation on HBKP fibers’ enzymatic hydrolysis was studied. The results showed that the enzymatic hydrolysis efficiency was enhanced obviously by mechanical refining. The mechanical refining alterated the fibers’ characteristics such as fibrillation degree, specific surface area, swelling ability, crystallinity, fiber length and fines content. All these factors correlating to the enzymatic hydrolysis were evaluated through mathematical analysis. Among these factors, the fibrillation degree has the profoundest impact on the enzymatic hydrolysis of wood fibers. Consequently, the mechanical refining aiming for a high fibrillation degree was feasible to enhance the enzymatic hydrolysis of lignocellulosic biomass. [ABSTRACT FROM AUTHOR]

Deep eutectic solvents (DES) have been regarded as green solvents in the biorefinery of lignocellulosic biomass, but long duration time has severely limited efficiency. The microwave-assisted DES pretreatment along with enzymatic hydrolysis and high-pressure homogenization process was proposed to produce lignin-containing cellulose nanofibrils (LCNF) from corncob. Benefiting from microwave-assisted DES pretreatment, the duration time was greatly shortened; meanwhile the effects of different kinds of DES on the resultant LCNF were investigated. The results showed that, the microwave-assisted DES fabricated LCNF (M-LCNF) was successfully obtained, exhibiting good nano size, thermal stability, colloidal stability, and fluorescence. M-LCNF was further introduced into phytic acid (PA) enhanced poly(acrylamide- co -acrylic acid) (P(AM-co-AA)) network and constructed composite conductive hydrogels (PLP). The obtained hydrogels exhibited good mechanical strength, UV blocking ability, fluorescence, and conductivity. A simple battery assembled with the resultant PLP as electrolyte had an out voltage of 2.41 V. The composite conductive hydrogel showed good sensing performance towards different stimuli (e.g., stretching and compression) and human motions in real time. It is expected that this research would provide an alternative way for green fabrication of LCNF and potential application of LCNF in flexible sensors. [Display omitted] [ABSTRACT FROM AUTHOR]

Lignocellulosic biomass exhibits a promising potential for production of carbon materials. Nitrogen and phosphorus co-doped carbon quantum dots (N,P-CQDs) were fabricated via (NH 4) 2 HPO 4 assisted hydrothermal treatment of cellulose pulp fibers. The as-prepared N,P-CQDs were characterized by HRTEM, FTIR, fluorescence and UV–vis, and then incorporated into g-C 3 N 4 (CN) through sonication and liquid deposition, forming N,P-CQDs/sonication treated g-C 3 N 4 (C-SCN) composites, which were then explored as photocatalysts. The photocatalytic ability of C-SCN towards model lignin was further analyzed. The results showed that, the fluorescence intensity and photoluminescence performance of N,P-CQDs were much higher than that of CQDs; the heterojunction was successfully constructed between the composites of N,P-CQDs and SCN; the incorporation of N,P-CQDs enhanced the visible light absorption, but reduced the band gap of the composite heterojunction; the resultant photocatalysts exhibited a good photocatalytic ability of model lignin via catalyze the fracture of β –O–4′ ether bond and C C bond, i.e., the photocatalytic degradation ratio reached up to 95.5 %; and the photocatalytic reaction generated some valuable organics such as phenyl formate, benzaldehyde, and benzoic acid. This study would promote the high value-added utilization of lignocellulosic resources especially in the transformation of lignin, conforming the concept of sustainable development. • Nitrogen and phosphorus co-doped CQDs was prepared from cellulose pulp. • N,P-CQDs exhibited a much better optical properties than CQDs. • N,P-CQDs/g-C 3 N 4 composites were fabricated and explored as photocatalysts. • N,P-CQDs enhanced photocatalytic capacity of CQDs/g-C 3 N 4 towards lignin model. • Some valuable chemicals were generated during the photocatalytic reaction. [ABSTRACT FROM AUTHOR]

[Display omitted] • Structural color has great potential in many fields such as biosensor and energy. • CNC can be used to effectively construct biomimetic materials with structural color. • Preparation of CNC and mechanism of resultant structural color are reviewed. • The materials that can modulate CNC structural color are classified and summarized. • The applications of chiral CNC based multifunctional materials are reviewed. Constructing and mimicking bioinspired structural color from bio-based materials has aroused tremendous attention. Cellulose nanocrystals (CNC), a typical nanomaterial made from lignocellulosic biomass, have been explored for the preparation of photonic materials. Structural color can be controllably achieved via incorporating different types of substances into CNC, which not only improves its mechanical properties but also adds new multifunctional properties. Herein, we provide a systematic summary of the following topics: 1) preparation of chiral cellulose nanocrystals, the iridescent mechanism of chiral CNC film, and the fundamentals of CNC suspensions on structural color formation; 2) construction of CNC-based composites with structural color by incorporating effective materials; and 3) potential applications of CNC-based composites in environment, advanced encryption, biomedicine, soft actuators, and energy storage. While numerous reviews on CNCs have appeared in the literature, there is still a lack of a comprehensive summary of the state-of-the-art on the preparation, iridescent mechanism, and applications of CNC-based composites, especially with regard to some advanced applications such as actuators and energy storage. To the best of our knowledge, this review represents a comprehensive and systematic description of the advances in bioinspired and multifunctional biomaterials from chiral CNC, and is believed to provide sufficient reference value for related aspects and promote the application of novel CNC-based composites in emerging areas. [ABSTRACT FROM AUTHOR]

[Display omitted] • The Pretreatment of NH 4 Cl impregnation and refining was environment friendly and low energy consumption. • 97.4 % of the xylose was recovered to improve the utilization of all-components from lignocellulose. • Energy consumption of the refining was hugely decreased by NH 4 Cl impregnation. • Bioethanol yield and recovery rate of xylose were 190 and 151 g/kg wood, respectively. A combined pretreatment of NH 4 Cl impregnation and refining was developed to recover the fermentable sugars and improve the bioethanol yield. The xylose was recovered to decrease the cost of bioethanol production, moreover, the impregnation using nonmetal salt had little influence on the environment, and the energy consumption of the refining process was hugely reduced by the impregnation. The results showed that a high-temperature, short-time impregnation (170 °C, 10 min) led mainly to hemicelluloses degradation, where 97.4 % of the xylose was recovered from the impregnation liquor. 97.9 % of the cellulose in the refined solid substrate (SS) was converted to glucose by enzymatic hydrolysis, and 80.3 % of which was further fermented to bioethanol. The pretreatment energy efficiency was up to 260 g sugar/MJ, nearly three times higher than that using H 2 O impregnation and refining. Finally, the bioethanol yield (BY) and the xylose recovery reached to 189.75 and 150.95 g/kg wood, respectively. [ABSTRACT FROM AUTHOR]

• Hydrothermal and Fenton pretreatment synergistically promote enzymatic hydrolysis. • Fenton pretreatment can help to solve inhibition of pseudo lignin problem. • Pre-hydrolysates provide additional revenues such as XOS, GOS, and xylose. • Main substrates' characteristics were changed by combined pretreatments. The combination of different pretreatment methods can effectively overcome recalcitrance of lignocellulosic biomass to ensure its highly efficient conversion into bio-based products. In this study, the combined pretreatments of chemical methods (hydrothermal treatment and Fenton treatment) with mechanical refining were used to improve the enzymatic hydrolysis efficiency of poplar branches. The results indicated that hydrothermal pretreatment and Fenton pretreatment can effectively improve the enzymatic hydrolysis of poplar substrates, e.g., the maximum glucose conversion yield and glucose concentration reached 92.4% and 20.8 g/L, respectively. The pre-hydrolysates contained some valuable components such as monosaccharides, oligosaccharides, acetic acid, furfural, and hydroxymethylfurfural. The main characteristics (specific surface area, water retention value, fines content, and surface lignin concentration) of poplar substrates were obviously changed by the combined pretreatment, which benefit the enzymatic hydrolysis. [ABSTRACT FROM AUTHOR]

• Three methods on enzymatic hydrolysis of corncob residues were compared. • Corncob residues substrate's main characteristics were changed by pretreatment. • Enzymatic hydrolysis efficiency were significantly enhanced by wet grinding. Under the situation of increasingly severe challenge of energy consumption, it is of great importance to make full use of bioresources such as forestry and agricultural residues. Herein, the corncob residues generated after processing corncob were enzymatically hydrolyzed to yield fermentable sugars. To overcome the recalcitrance of corncob residues, three kinds of pretreatment methods, i.e., sulfonation, PFI refining, and wet grinding, were applied; their effects on enzymatic hydrolysis and main characteristics of corncob residues substrate were investigated. The results showed that the enzymatic digestibility of the substrate was greatly enhanced by employing each method. The wet grinding exhibited obvious advantages, e.g., the conversion yield of cellulose to glucose and glucose concentration reached 96.7% and 32.2 g/L after 59 h of enzymatic hydrolysis, respectively. The improvement in enzymatic hydrolysis was mainly attributed to the altered characteristics of the substrate such as swelling ability, specific surface area, and particle size and distribution. [ABSTRACT FROM AUTHOR]