Natural Lignocellulose Research Articles

Leaftronics: Natural lignocellulose scaffolds for sustainable electronics.

The global rise in electronic waste is alarming, driven by the persistent use of glass, epoxy, and plastic substrates owing to their cost, stability, flexibility, and transparency. This underscores the need for biodegradable alternatives with similar properties. This study shows that leaf-derived lignocellulose scaffolds can stabilize bio-sourced, solution-processed polymers by acting as natural sequestering media. Such reinforced films, even when based on gelatin (Tg ~ 60°C), can endure processes over 200°C. We demonstrate dip-coated ethyl cellulose films for commercially viable reflow soldered circuitry. The films offer high flexibility, more than 80% transparency, and surface roughness below 5.5 nm. Advanced OPDs and OECTs fabricated on these films perform comparably to those on glass and the low material cost and simple fabrication process yields a minimal carbon footprint of 1.6 kgCO2/m2. This work thus opens a vista of possibilities for biodegradable polymers heretofore considered unsuitable for making temperature-stable substrates for state-of-the-art electronics applications.

IDENTIFICATION OF LIGNOCELLULOSE-LIKE MATERIAL USING SPECTROSCOPY ANALYSIS

Lignocellulose materials, such as bamboo, rattan, and wood, have been largely used for furniture and crafts. On the other hand, the utilization of lignocellulose-like materials, which have a similar texture and appearance to those from nature, has been increasing recently due to their superior durability. This research aimed to identify the lignocellulose-like material using spectroscopy analysis, such as Raman and Near Infrared (NIR) which is well-known as a non-destructive, quick, and accurate approach for material identification. We investigated 4 types of lignocellulose-like materials that were provided by Dewan Serat Indonesia (The Indonesian Fiber Council) from an industry that produces them. The NIR analysis was performed at wavenumbers 10,000-4,000 cm-1. The natural lignocellulose (bamboo and wood) and the polymers (polyethylene and polyproline) were used as standards. Raman analysis was further employed to identify the composition of selected lignocellulose-like materials by comparing their spectra with the library software. The results showed that the original NIR spectra of lignocellulose-like and those natural materials were different, indicating that the NIR analysis can differentiate those materials. The NIR spectra of lignocellulose-like materials were similar to those of polyethylene spectra. Those lignocellulose-like were also identified as polyethylene due to the similarity of the Raman spectra and their library spectra.

Enhancing the H2 yield from photoreforming of natural lignocellulose feedstock by two-stage thermo-alkaline hydrolysis pretreatment

Two-stage thermo-alkaline hydrolysis (TS-TAH) boosts H2 yield by simply applying a commercial SrTiO3 catalyst in natural lignocellulose photoreforming processes.

Agrobacterium tumefaciens-mediated transformation of the white-rot fungus Dichomitus squalens

Dichomitus squalens is an efficient white-rot fungus that generates a wide range of extracellular enzymes to degrade lignocellulose in nature. Although a protoplast-mediated transformation method for D. squalens has been developed, the transformation efficiency remains low. Here, we established a highly efficient Agrobacterium tumefaciens-mediated transformation (ATMT) procedure for D. squalens by transferring a binary vector harboring the neomycin phosphotransferase II (nptII) resistance gene fused with DsRed-Express2, under the control of the native glyceraldehyde-3-phosphate dehydrogenase (GPD) gene promoter. Key factors affecting the efficiency of transformation were tested. A. tumefaciens EHA105 strain with a cell density of 0.4 OD600nm and 96 h co-cultivation resulted in the highest transformation efficiency, with an average of 98 ± 11 transformants per co-cultivation plate. Besides, the strong expression of DsRed-Express2 indicates the effectiveness of the DsGPD promoter in driving gene expression in D. squalens. This ATMT system of D. squalens would be beneficial for its molecular genetic studies.

Ferulic acid production from wheat bran by integration of enzymatic pretreatment and a cold-adapted carboxylesterase catalysis

High-value chemical production from natural lignocellulose transformation is a reliable waste utilization approach. A gene encoding cold-adapted carboxylesterase in Arthrobacter soli Em07 was identified. The gene was cloned and expressed in Escherichia coli to obtain a carboxylesterase enzyme with a molecular weight of 37.2 KDa. The activity of the enzyme was determined using α-naphthyl acetate as substrate. Results showed that the optimum enzyme activity of carboxylesterase was at 10 °C and pH 7.0. It was also found that the enzyme could degrade 20 mg enzymatic pretreated de-starched wheat bran (DSWB) to produce 235.8 μg of ferulic acid under the same conditions, which was 5.6 times more than the control. Compared to the chemical strategy, enzymatic pretreatment is advantageous because it is environmentally friendly, and the by-products can be easily treated. Therefore, this strategy provides an effective method for high-value utilization of biomass waste in agriculture and industry.

Preparation of lignin nanoparticles via ultra-fast microwave-assisted fractionation of lignocellulose using ternary deep eutectic solvents.

Lignin separation from natural lignocellulose for the preparation of lignin nanoparticles (LNPs) is often challenging owing to the recalcitrant and complex structure of lignocellulose. This paper reports a strategy for the rapid synthesis of LNPs via microwave-assisted lignocellulose fractionation using ternary deep eutectic solvents (DESs). A novel ternary DES with strong hydrogen bonding was prepared using choline chloride, oxalic acid, and lactic acid in a 1:0.5:1 ratio. Efficient fractionation of rice straw (0.5 × 2.0 cm) (RS) was realized by the ternary DES under microwave irradiation (680 W) within only 4 min, and 63.4% of lignin could be separated from the RS to prepare LNPs with a high lignin purity (86.8%), an average particle size of 48-95 nm, and a narrow size distribution. The mechanism of lignin conversion was also investigated, which revealed that dissolved lignin aggregated into LNPs via π-π stacking interactions.

Self-cleaning solar water evaporation device based on polyaniline/TiO2/natural cellulose fibers for contaminant water

Wastewater accounts for a large part of the water body on the earth. Solar water evaporation is an effective way to produce fresh water from seawater or polluted water. However, the co-evaporation or deposition of contaminants may reduce the efficiency and freshwater quality during water evaporation. In this work, a self-cleaning solar water evaporator is developed based on the natural lignocellulose fibers (NCF), polyaniline (PANI), and TiO2, which shows great advantages of wide-range light absorption, super hydrophilicity, and low thermal conductivity. Nanofibrous PANI is polymerized on the surface of NCF to form a mesoporous network by adding the NCF to the polymerization solution. P25 TiO2 nanoparticles as photocatalysts are dispersed into the above reaction to form the hybrid PANI/TiO2/NCF composite disc by simply filtration. Owing to the synergistic effect between the photothermal PANI and the photocatalytic degradation of TiO2 nanoparticles in the solar water evaporator device, the water evaporation rate can reach 2.36 kg m−2 h−1 (under 1 sun irradiation), and the contaminant (100 ppm tetracycline) can be efficiently degraded. Interestingly, the solar water evaporator device still maintains a constant solar evaporation rate after working for 10 h, and no contaminant is accumulated. The bifunctional solar water evaporation device, which combines photocatalytic and photothermal effects, has great potential application in organic contaminant water with a self-cleaning effect.

Titica Vine Fiber (Heteropsis flexuosa): A Hidden Amazon Fiber with Potential Applications as Reinforcement in Polymer Matrix Composites

The titica vine fiber (TVF) (Heteropsis flexuosa) is a natural lignocellulose fiber (NLF) from the Amazon rainforest that was, for the first time, investigated in terms of its basic properties such as dimensions, porosity, and density as well as its chemical composition, moisture content, crystallinity, and microfibrillar angle. In this study, the apparent density of TVF was determined as one of the lowest-ever reported for NLFs). Using both the geometric method and Archimedes’ principle, density values in the range of 0.5–0.6 g/cm3 were obtained. The moisture content was measured as around 11%, which is in accordance with the commonly reported values for NLFs. The TVF exhibited a high porosity, approximately 70%, which was confirmed by SEM images, where a highly porous morphological structure associated with the presence of many voids and lumens was observed. The crystallinity index and microfibrillar angle were determined as 78% and 7.95°, respectively, which are of interest for a stiff NLF. A preliminary assessment on the mechanical properties of the TVFs revealed a tensile strength, Young’s modulus, and elongation of 26 MPa, 1 GPa, and 7.4%, respectively. Furthermore, the fiber presented a critical length of 7.62 mm in epoxy matrix and an interfacial shear strength of 0.97 MPa. These results suggest the TVFs might favors applications where lighter materials with intermediate properties are required.

Effect of pretreatment on solid‐state fermentation of natural lignocellulose by Aspergillus fumigatus G‐13

AbstractIn order to efficiently utilize lignocellulosic materials, different treatment methods were used to pretreat lignin. In this research, three pretreatment methods, physical pretreatment, chemical pretreatment, and combined physical and chemical pretreatment, were used to investigate the effect of different pretreatment ways on the solid‐state fermentation of lignocellulosic biomass (straw, locust, and walnut shell) by Aspergillus fumigatus G‐13, and the physical and chemical structure changes of the materials before and after pretreatment and fermentation were also analyzed. The study concluded that physical–chemical combined pretreatment was most beneficial to enzyme production. The optimized pretreatment method is that the particle size is 60–80 mesh, the solid‐to‐liquid volume ratio is 1:1.5, and the 8% Ca(OH)2 solution is pretreated at 60°C for 48 h. The maximum enzyme activity was increased by 4.81–28.91 times for the locust, with 7.68–35.20 times for the walnut shell. Research indicated that the combined pretreatment could change the crystallinity and microcrystalline size of lignocellulose samples. In addition, it broke the ester and ether bonds between lignin and hemicellulose as well as weakened the hydrogen bond between hemicellulose and cellulose.

Natural lignocellulose welded Zr–Al bimetallic hybrids for the sustainable conversion of xylose to alkyl levulinate

The processing of C6 sugars to alkyl levulinate (AL), a versatile biomass-derived building block, can be readily implemented via the straightforward acid-catalyzed reaction in alcohol medium while it remains a challenge to produce AL from C5 sugars in the one-pot procedure over a monolithic catalyst. In this contribution, a budget and multifunctional natural lignocellulose welded Zr–Al bimetallic hybrid (ZrAl@CS-MSA) has been successfully constructed with crude corn stalk as a sustainable support. The becoming Lewis and Brønsted acid sites of ZrAl@CS-MSA catalyst guarantee a high AL yield of 54.3% from xylose via a one-pot process in a renewable n-butanol medium. Experimental findings revealed that the sulfonic group of ZrAl@CS-MSA plays a significant role in the xylose dehydration, furfuryl alcohol etherification and alcoholysis reactions while Zr species is in charge of the transfer hydrogenation of furfural. The Al species enclosed in ZrAl@CS-MSA can regulate its Brønsted and Lewis acidity, accelerating the etherification and alcoholysis reactions as well as alleviating the over hydrogenation of AL. This work opens a green, sustainable and reliable avenue for producing C5 sugar-based AL using natural lignocellulose-related multifunctional catalysts.

Pretreatment of Natural Lignocellulose with Inorganic Salts Improves Ligninase Production Fermented by Aspergillus fumigatus

This work screened out the optimal conditions for pretreatment of natural lignocellulose with inorganic salts and provided a simple, easy-to-operate, low-cost, clean and efficient pretreatment method for the efficient degradation of natural lignocellulose by strains. The results showed that the optimal pretreatment inorganic salt was FeCl2 with a concentration of 11%, pretreatment at 60 °C for 48 h, and the solid–liquid ratio was 1:11 (g/mL). According to the characterization results, after pretreatment of FeCl2 solution, the smooth and dense structure of natural lignocellulose surface became rough and irregular, and surface fiber bundles showed spalling and fracture. Subsequently, the enzymes produced by solid-state fermentation of Aspergillus fumigatus were easier to enter the interior, which increased the contact area between materials and enzymes, and increased the amount of enzymatic loads, thereby improving the biodegradation effect.

Current Progress in Optimising Sustainable Energy Recovery From Cattle Paunch Contents, a Slaughterhouse Waste Product

Paunch contents are the recalcitrant, lignocellulose-rich, partially-digested feed present in the rumen of ruminant animals. Cattle forage in Europe is primarily from perennial and Italian ryegrasses and/or white clover, so paunch contents from forage-fed cattle in Europe is enriched in these feedstuffs. Globally, due to its underutilisation, the potential energy in cattle paunch contents annually represents an energy loss of 23,216,548,750–27,804,250,000 Megajoules (MJ) and financial loss of up to ~€800,000,000. Therefore, this review aims to describe progress made to-date in optimising sustainable energy recovery from paunch contents. Furthermore, analyses to determine the economic feasibility/potential of recovering sustainable energy from paunch contents was carried out. The primary method used to recover sustainable energy from paunch contents to-date has involved biomethane production through anaerobic digestion (AD). The major bottleneck in its utilisation through AD is its recalcitrance, resulting in build-up of fibrous material. Pre-treatments partially degrade the lignocellulose in lignocellulose-rich wastes, reducing their recalcitrance. Enzyme systems could be inexpensive and more environmentally compatible than conventional solvent pre-treatments. A potential source of enzyme systems is the rumen microbiome, whose efficiency in lignocellulose degradation is attracting significant research interest. Therefore, the application of rumen fluid (liquid derived from dewatering of paunch contents) to improve biomethane production from AD of lignocellulosic wastes is included in this review. Analysis of a study where rumen fluid was used to pre-treat paper sludge from a paper mill prior to AD for biomethane production suggested economic feasibility for CHP combustion, with potential savings of ~€11,000 annually. Meta-genomic studies of bacterial/archaeal populations have been carried out to understand their ruminal functions. However, despite their importance in degrading lignocellulose in nature, rumen fungi remain comparatively under-investigated. Further investigation of rumen microbes, their cultivation and their enzyme systems, and the role of rumen fluid in degrading lignocellulosic wastes, could provide efficient pre-treatments and co-digestion strategies to maximise biomethane yield from a range of lignocellulosic wastes. This review describes current progress in optimising sustainable energy recovery from paunch contents, and the potential of rumen fluid as a pre-treatment and co-substrate to recover sustainable energy from lignocellulosic wastes using AD.

Designing of biomass-derived carbon quantum dots@polyvinyl alcohol film with excellent fluorescent performance and pH-responsiveness for intelligent detection

Carbon quantum dots (CQDs) have attracted extensive attentions because of their unique luminescent properties and promising prospects in intelligent sensing and detection. However, the increasing environmental pollution caused by chemical substances for synthesizing illuminants limits their expansion in practical applications. Herein, we employed a facile and green synthesis strategy to extract biomass-derived CQDs from natural lignocellulose. The obtained CQD nanoparticles not only showed excellent fluorescent performance, but also posed desirable environmental-friendly characteristic. Moreover, to relieve the fluorescence quenching induced by CQDs aggregation, the well-dispersed CQDs@polyvinyl alcohol (CQDs@PVA) composite film with strong hydrogen-bond interaction was successfully fabricated. The resultant film exhibited high transparency (transmittance of 88%), excellent mechanical flexibility (tensile strength of 39.7 MPa and elongation at break of 453%), and exceptional fluorescence performance. The high concentrated emitting centered in 502 nm emission wavelength was realized in a wide excitation range of 350 ∼ 420 nm with high-stability turquoise fluorescence. More impressively, this fluorescent film demonstrated a sensitive pH-responsiveness, i.e., the fluorescent intensity varied upon pH stimulation. As a proof-of-concept, an intelligent pH-detector based on this fluorescent film was rationally designed for real-time sensing and detection of pH variation in human sweat during movement processing. From fundamental materials to desired applications, this study not only enriches the synthetic strategy of illuminants in an environment-friendly manner, but also paves the way for further applications in wearable, real-time health monitoring.

Cover Feature: Preparation, Properties, and Application of Lignocellulosic‐Based Fluorescent Carbon Dots (ChemSusChem 8/2022)

The Cover Feature shows a kind of fluorescent carbon dots (LC-CDs) prepared from natural lignocellulose materials. LC-CDs present spherical nanoparticles of graphite oxide-like structure with good physicochemical stability. They also display excellent optical properties such as photoluminescence, fluorescence quenching, and multicolor fluorescence, which could be widely applied in the field of bioimaging, sensors, and catalysis. More information can be found in the Review by X. Song et al.

Fabrication of lignin-containing cellulose bio-composite based on unbleached corncob and wheat straw pulp

In contemporary life, plastic, a kind of petroleum carbon source, has been produced and used in varieties of applications. However, the vast consumption of petroleum-based plastic and the burning of agricultural wastes make the environmental problems increasingly severe. Furthermore, a large number of lignocellulosic resources (such as corncob and wheat straw) are often wasted and burned, which will aggravate the environmental damage. In this paper, we use unbleached corncob and wheat straw pulp to fabricate the lignin-containing cellulose bio-composites (LCBs) to reduce non-renewable energy consumption and utilize agricultural wastes. The LCBs were obtained by a direct manufacturing process in benzyltrimethyl ammonium hydroxide (BzMe3NOH) aqueous solution under mild conditions, constituting an entwined composite structure of cellulose micro/nano-fibers. This unique micro/nano-structure provides bio-composites with the outstanding mechanical performance of 96.7 MPa and a high haze of 90.1%. Meanwhile, with the inherent lignin, the LCBs could filter over 81.8% UV-C. As the raw material used is pure natural lignocellulose, the bio-composites prepared have innate environmental friendliness. With exceptional mechanical strength, UV-shielding property, and innate environmental friendliness, the LCBs are possible and potential substitutes for traditional petroleum-based plastic that is easily aging or non-biodegradable.

Enhancing H2 Yield from Photoreforming of Natural Lignocellulose Feedstock by Two-Stage Thermo-Alkaline Hydrolysis Pretreatment

Enhancing H2 Yield from Photoreforming of Natural Lignocellulose Feedstock by Two-Stage Thermo-Alkaline Hydrolysis Pretreatment

Design of a Multifunctional Zirconium-Based Hybrid with Natural Lignocellulose for Transfer Hydrogenation of Furfural to Furfuryl Alcohol

Hydrogenation reduction of furfural (FAL) to furfuryl alcohol (FOL) confirms the requirement of sustainable development of society. The key to realize this transformation is to design a cost-effective and environmental catalyst with both Lewis acid and Lewis base sites. Here, we report the preparation of a multifunctional zirconium-based hybrid (Zr@PS-MSA) using Pennisetum sinese (PS), an annual natural lignocellulose, as a natural organic ligand. The prepared hybrid was used as an efficient catalyst for catalytic transfer hydrogenation (CTH) of FAL to FOL in isopropanol, and a high yield of up to 99.6% was accomplished by manipulating exposed versatile acid–base sites. Further studies indicated that Zr@PS-MSA possessed remarkable cycle stability and could be consecutively run at least 6 times without significant change in the catalytic activity. Mechanistic studies for CTH of FAL to FOL through isotopically labeled 2-propanol-d8 experiments evidently demonstrate FAL reduction via intermolecular hydrogen transfer. More gratifyingly, Zr@PS-MSA can also efficiently catalyze the various biomass-derived carboxides to corresponding alcohols, with yields of up to 92.4%.

Gel Polymer Electrolyte with High Performances Based on Polyvinylidene Fluoride Composite Eco-Friendly Lignocellulose for Lithium-Ion Batteries

Abstract ： A high-performance gel polymer electrolyte (GPE) based on polyvinylidene fluoride (PVDF) and natural lignocellulose (LC) was successfully prepared via a simple coating method. The mechanical strength of the composite membrane is greatly enhanced and the dissociation of lithium salt is significantly promoted. Additionally, when the content of PVDF is 30 wt.%, the prepared composite membrane presents high liquid electrolyte (LE) uptake (205 wt.%) and excellent thermal stability. The corresponding GPE exhibits high ionic conductivity of 1.44 mS cm -1 and good compatibility with lithium anode. Moreover, the corresponding Li||GPE||LiFePO4 battery maintains a relatively high capacity after being tested for 300 cycles at a rate of 1.0 C, showing excellent cycle performance.

Surface Treatments of Coffee Husk Fiber Waste for Effective Incorporation into Polymer Biocomposites.

Natural lignocellulose fibers have been extensively investigated and applied as a reinforcement of polymer composites in industrial applications from food packing to automotive parts. Among the advantages of natural fibers stands their relatively low cost and sustainable characteristics. These are accentuated in the case of residual fibers such as those obtained from coffee husks, an agribusiness waste, usually burnt or disposed into the environment. As composite reinforcement, hydrophilic natural fibers display adhesion problems to the most hydrophobic polymer matrices. This adhesion might be improved with distinct types of fibers surface treatments. In the present work, the effectiveness of three surface treatments applied to coffee husk fiber wastes (CHFW) were investigated, aiming to improve the tensile performance of castor oil-based polyurethane (COPU) biocomposites. The effects of treatments associated with (i) chemical with sodium hydroxide, (ii) physical by temperature and pressure and hydrothermic treatment, and (iii) biological by fermentation with Phanerochaete Chrysosporium fungus were evaluated by means of Fourier transformed infrared spectroscopy, X-ray diffraction, thermal analyses and morphology by scanning electron microscopy for different concentration of NaOH, different hydrothermic times at 121 °C/98 kPa and exposition to P. chrysosporium. The most effective treatment was the hydrothermal one at 121 °C and 98.06 kPa for 30 min. Preliminary tensile tests were performed in COPU biocomposites reinforced with 20% CHFWs subjected to the optimized conditions for each distinct type of treatment. The results indicated that the hydrothermal treatment promoted significant enhancement in the fiber/matrix interfacial bond, increasing the tensile strength up to 60% compared to COPU reinforced with in natura CHFWs fibers. It is important to mention that these composites can be applied as plastic wood for household items’ internal parts and in the automobile industry.

Metagenomic Insight into Lignocellulose Degradation of the Thermophilic Microbial Consortium TMC7.

Biodegradation is the key process involved in natural lignocellulose biotransformation and utilization. Microbial consortia represent promising candidates for applications in lignocellulose conversion strategies for biofuel production; however, cooperation among the enzymes and the labor division of microbes in the microbial consortia remains unclear. In this study, metagenomic analysis was performed to reveal the community structure and extremozyme systems of a lignocellulolytic microbial consortium, TMC7. The taxonomic affiliation of TMC7 metagenome included members of the genera Ruminiclostridium (42.85%), Thermoanaerobacterium (18.41%), Geobacillus (10.44%), unclassified_f__Bacillaceae (7.48%), Aeribacillus (2.65%), Symbiobacterium (2.47%), Desulfotomaculum (2.33%), Caldibacillus (1.56%), Clostridium (1.26%), and others (10.55%). The carbohydrate-active enzyme annotation revealed that TMC7 encoded a broad array of enzymes responsible for cellulose and hemicellulose degradation. Ten glycoside hydrolases (GHs) endoglucanase, 4 GHs exoglucanase, and 6 GHs β-glucosidase were identified for cellulose degradation; 6 GHs endo-β-1,4-xylanase, 9 GHs β-xylosidase, and 3 GHs β-mannanase were identified for degradation of the hemicellulose main chain; 6 GHs arabinofuranosidase, 2 GHs α-mannosidase, 11 GHs galactosidase, 3 GHs α-rhamnosidase, and 4 GHs α-fucosidase were identified as xylan debranching enzymes. Furthermore, by introducing a factor named as the contribution coefficient, we found that Ruminiclostridium and Thermoanaerobacterium may be the dominant contributors, whereas Symbiobacterium and Desulfotomaculum may serve as "sugar cheaters" in lignocellulose degradation by TMC7. Our findings provide mechanistic profiles of an array of enzymes that degrade complex lignocellulosic biomass in the microbial consortium TMC7 and provide a promising approach for studying the potential contribution of microbes in microbial consortia.