Lignin Nanospheres Research Articles

Thiol and amino co-grafting modification of sugarcane bagasse lignin nanospheres to enhance the adsorption capacity of cadmium ion

Divalent cadmium ions in the water environment are a serious threat to human health. The purpose of this study is to develop a biodegradable bio-adsorbent based on bagasse lignin and can effectively adsorb cadmium ions. In this study, it was found that the thiol amino co-grafted lignin nanospheres (TALNPs) had been successfully prepared by the Mannich reaction system, and the performance tests indicate that TALNPs have good adsorption potential. The evaluation experiment shows that factors such as pH value, dosage, time, initial concentration, and temperature significantly affect the ability of TALNPs to adsorb cadmium ions. The simulation calculation of isothermal adsorption experiment shows that the adsorption of cadmium ions follows the Langmuir model, and the adsorption kinetics is pseudo-second order. Compared with unmodified lignin, the ability of TALNPs has increased by about 3.5 times. Using XPS to analyze the structure of TALNPs in the adsorption and desorption process shows that only the bridge bond changes, indicating that it is a relatively stable adsorbent and can be reused. In general, the design strategy of thiol-amino co-grafting to modify lignin nanospheres can enhance the adsorption of cadmium ions, and also provide a new way for the development and utilization of bagasse lignin.

Gradient-Layered MXene/Hollow Lignin Nanospheres Architecture Design for Flexible and Stretchable Supercapacitors

HighlightsA novel gradient-layered architecture based on single-pore hollow lignin nanospheres (HLNPs)-intercalated MXene layers was created to fabricate highly stretchable (600%) and durable (1000 cycling) supercapacitor electrodes.The architecture reduced the overstacking of MXene, and the micro-chamber structure of HLNPs better utilized lignin’s pseudocapacitive property to improve ion and electron accessibility (specific capacitance reached 1273 mF cm−2).HLNPs enhanced mechanical durability and capacitive stability of the integrated wrinkled electrodes during the stretch-release cycling.

Excellent facile fabrication of PVA and lignin nanoparticles from wheat straw after novel DES-THF pretreatment

The utilization of environmental friendly and renewable materials has received increasing attention recently. Lignin nanospheres (LNPs) prepared from recovered lignin and residual lignin after DESs and DESs-THF pretreatment were obtained by self-assembly in the present research. Then, films were prepared by incorporating them into polyvinyl alcohol (PVA) solution. The properties of various films were characterized and compared. Results showed that as the LNPs content increased, the UV blocking capacity of the films was gradually enhanced than PVA film. The DES-THF films showed better antioxidant properties up to 69 % due to higher phenolic hydroxyl content. The hydrophobicity of films incorporated with DESs-THF pretreated lignin was consistently better than that of DES pretreated. DES-THF-M films showed a higher Tmax than that of DES-M films, resulting in better thermal stability. Moreover, DES-THF-L films are lighter in color due to a lower degree of condensation, which is favorable to subsequent applications. The incorporation of LNPs improved mechanical and antioxidant properties, thermal stability, and UV shielding ability of PVA films, especially lignin after DES-THF pretreatment. In conclusion, the prepared PVA/LNPs composite films possessed good functional properties that make them potential for packaging materials.

Preparation of Alkali-Resistant Lignin Nanospheres Loaded with Silver Nanoparticles and Their Applications Toward Antibiosis and Printing.

Lignin nanoparticles (LNPs) loaded with silver nanoparticles have exhibited significant application potential in antibacterial and catalytic fields. However, the high solubility of LNPs in silver ammonia solution makes it difficult to achieve the reduction of Ag+ and the adsorption of silver nanoparticles. In this study, a protecting agent, terephthalic aldehyde (TA) is used to block lignin condensation and introduce aldehyde groups onto the lignin molecular backbone during lignin extraction. Furthermore, the TA stabilized lignin (TASL) is cross-linked with bisphenol A diglycidyl ether (BADGE) to enhance its alkali resistance performance and subsequently prepared into alkali-resistance BADGE- TASL hybrid LNPs (BADGE- TASL hy-LNPs) by anti-solvent precipitation and self-assembly. Because the presence of a large number of aldehyde groups in TASL compensates for the loss of phenolic hydroxyl groups caused by crosslinking reactions, a high loading of silver nanoparticles of 54.00% is obtained after redox reaction and adsorption in silver ammonia solution. When the BADGE-TASL hy-LNPs@Ag is used as an antibacterial agent, its inhibition efficiency reached ≈99%. Besides, the BADGE-TASL hy-LNPs@Ag can serve as a printing material for the preparation of conductive printing ink. Therefore, this study provides a strategy for lignin functionalization and application in printed electronics and antimicrobial fields.

Preparation and characterization of mesoporous HA coating with paclitaxel loaded lignin nanospheres on titanium surface

BackgroundPrimary malignant bone tumor is a disease that can lead to death. The usually applied clinical treatment strategy is surgical resection of the primary tumor. However, tumor cells are difficult to clean up, easy to make the tumor recurrence, and the bone defect caused by surgical resection also hindered the postoperative recovery. Materials and methodsHerein, in this work, mesoporous hydroxyapatite (HA) coating with petal-structure was prepared on titanium (Ti) implant surfaces by micro-arc oxidation (MAO) to accelerate the bone growth, and then paclitaxel (PTX) loaded lignin nanospheres were deposited into the HA coatings to get a sustained release for killing residual tumor cells. ResultsThe results showed that many gaps and holes of micro-scale were formed in the petal-structured HA coatings, they worked as traps for the PTX loaded nanospheres to enhance the deposited amount and immobilization stability, playing good role of drug loading platform. The encapsulation of PTX by lignin ensured a lower release rate and a higher sustaining release time when compared with the PTX without encapsulation. In addition, the HA coating with PTX loaded lignin nanospheres showed higher killing effect to tumor cells than to osteoblast. ConclusionThe mesoporous HA coating with paclitaxel loaded lignin nanospheres endowed the titanium surface with good biological property and tumor cell-killing effect, so the obtained Ti-based material had a highly hopeful application as the localized implant for therapy of primary malignant bone tumor.

Pickering emulsion via interfacial assembly of lignin particles and cationic surfactant: Formation of robust anchoring layer

Lignin, a byproduct of the paper and pulp industry, shows promise as stabilizers for emulsions, offering potential value-added applications to direct disposal. However, utilizing particulate lignin directly as stabilizers is challenging due to limited emulsion stability. In this study, co-stabilization of Pickering emulsions is investigated by combination of lignin particles and cationic surfactants (CTAB and DDAB), wherein lignin source and oil types are optimized with a focus on emulsion stability. A battery of characterization methods, including visual appearance, microstructure, droplet size, zeta potential, etc., is employed to evaluate emulsion stability. The findings reveal that kraft lignin nanospheres (LNS) are the optimal stabilizing particles. The incorporation of cationic surfactants via electrostatic adsorption enhances the stabilizing effect of LNS, and the use of DDAB is found to significantly enhance emulsion stability compared to CTAB, attributing to higher charge shielding capability of DDAB, as well as the formation of a more robust and compact nonpolar anchoring layer. The surfactant-assisted LNS can be used to stabilize a range of oil types, with tridecane as the optimal oil. This research presents a straightforward, efficient, and scalable approach for producing highly stable lignin-based Pickering emulsions, showing potential applications in recycling and value enhancement of waste lignin.

Plant cell wall inspired lignin-based membrane with configurable radical scavenging activity

Natural antioxidants have received considerable attention due to their inherent biocompatibility and biodegradability, yet inferior antioxidant, storage instability, and structural heterogeneity limit applications. Drawing inspiration from plant structures, we develop antioxidant membranes that are entirely biomass-derived, metal-free, and customizable, using the layer-by-layer (LBL) assembly technique. The natural polyphenolic lignin co-assembles with lauryl alcohol derived from cassia bark into macroporous spherical particles in a γ-valerolactone (GVL)/water mixture, in which the pore size can be facilely adjusted by modulating feed ratio. Furthermore, the lignin nanospheres’ free radical scavenging ability is greatly enhanced by enlarging the pore size, offering an alternative way to improve the antioxidant performance. As the hydrophilic shells of lignin spherical assemblies display a strong affinity towards holocellulose nanofibrils (HCNF), multilayered antioxidant membranes with stable mechanical strength are constructed. The entirely biomass-derived antioxidant membrane has proven effective in recycled antioxidative microfiltration applications, demonstrating more than 90 % scavenging activity over seven cycles. Moreover, it exhibits biodegradability even in harsh conditions, with temperatures below 280 K and relative humidity less than 30 RH%. This work illuminates new possibilities for applying natural antioxidants in precise control materials.

Pea-like inspired design: Lignin nanospheres-mediated PVA film with high strength, low water evaporation permeability, strong UV resistance and anti-oxidation properties for extending food freshness

The excessive utilization of petroleum-based plastic products has inflicted significant harm upon the ecological and health problems, compelling individuals to continually seek renewable and biodegradable polymer materials as alternatives. Drawing inspiration from the structure of a natural pea pod, a unique interlocking packaging material based on a pea-like structure is obtained via green electrospinning and mild glutaraldehyde (GA) cross-linking method. Herein, polyvinyl alcohol (PVA) serves as a green protective layer encompassing the active lignin nanospheres (LNP) pod, forming a packaging film that prevents LNP migration. The LNP within the fibers can effectively shorten the fiber spacing, and when exposed to the GA vapor, they promote the bonding between neighboring fibers to form a tight interlock structure. Benefiting from the interlocking pea-like structure, the film exhibits excellent tensile strength (3.53 ± 0.02 MPa), wetting strength (1.92 ± 0.05 MPa), and outstanding water vapor barrier properties (3.27 ± 0.3 10−10 gm−1 s−1 Pa−1). Furthermore, the inclusion of LNP endows exceptional water resistance, UV-blocking capabilities, antibacterial and antioxidant properties, which can effectively prolong the storage life of perishable fruits. This eco-logical sustainable design holds tremendous potential in mitigating the burden on the environment, thus making a novel avenue for exploring alternatives to petroleum-derived plastics.

Fully upgrade bamboo biomass into three multifunctional products through biphasic γ-valerolactone and aqueous phosphoric acid pretreatment

In this manuscript, three components of lignocellulosic biomass were obtained by deconstructing bamboo with γ-valerolactone-H2O biphasic system, and the delignification rate of 80.92 % was achieved at 120 °C for 90 min. Lignin nanospheres with diameters ranging from 75 nm to 2 um could be customized by varying the self-assembly rate. Furthermore, the lignin nanospheres-poly(vinyl alcohol) film was prepared by cross-linking lignin nanospheres and poly(vinyl alcohol), which can obtain 90 % ultraviolet absorption capacity, while the light transmittance in non-ultraviolet band was almost unchanged. At the same time, due to the strong hydrogen formation between lignin nanospheres and poly(vinyl alcohol) bond network, the tensile properties of the composite film were also improved by 30 %. Besides, the high specific surface area of biomass-derived porous biochar (2056 m2/g) can be obtained after carbonization of solid residues at 850 °C for 2 h, which was almost 8 times the specific surface area of the direct biomass carbonization due to the removal of lignin and hemicellulose. biomass-derived porous biochar can be used as an adsorbent, with a CO2 capture capacity of 4.5 mmol g−1 at normal temperature (25 °C, 1 bar). The filtrate after the reaction contained a large amount of hemicellulose oligomers, which can be reacted with dichloromethane at 170 °C for 1 h to obtain the furfural yield of 74 %. In summary, the proposed biorefinery scheme achieves a full-component upgrade of lignocellulose and can be further applied in various downstream fields.

A novel seawater hydrothermal-deep eutectic solvent pretreatment enhances the production of fermentable sugars and tailored lignin nanospheres from Pinus massoniana

Lignocellulose biorefinery depended on effective pretreatment strategies is of great significance for solving the current global crisis of ecosystem and energy security. This study proposes a novel approach combining seawater hydrothermal pretreatment (SHP) and microwave-assisted deep eutectic solvent (MD) pretreatment to achieve an effective fractionation of Pinus massoniana into high value-added products. The results indicated that complex ions (Mg2+, Ca2+, and Cl−) in natural seawater served as Lewis acids and dramatically promoted the depolymerization of mannose and xylan into oligosaccharides with 40.17 % and 75.43 % yields, respectively. Subsequent MD treatment realized a rapid and effective lignin fractionation (~90 %) while retaining cellulose. As a result, the integrated pretreatment yielded ~85 % of enzymatic glucose, indicating an eightfold increase compared with untreated pine. Because of the increased hydrophobicity induced by the formation of acyl groups during MD treatment, uniform lignin nanospheres were successfully recovered from the DES. It exhibited low dispersibility (PDI = 2.23), small molecular weight (1889 g/mol), and excellent oxidation resistance (RSI = 5.94), demonstrating promising applications in functional materials. The mechanism of lignin depolymerization was comprehensively elucidated via FTIR, 2D-HSQC NMR, and GPC analyses. Overall, this study provides a novel and environmentally friendly strategy for lignocellulose biorefinery and lignin valorization.

Lignin-modified graphitic carbon nitride nanotubes for photocatalytic H2O2 production and degradation of brilliant black BN

As a renewable aromatic compound with enormous production potential, lignin has various potential high-value utilization pathways, but the success achieved in the field of photocatalysis is limited. Herein, this work prepares a new type of photocatalyst by modifying Graphitic Carbon Nitride Nanotubes (CNT) with self-assembled lignin nanospheres for the photocatalytic production of H2O2 and the degradation of azo dyes. Under light conditions, lignin enhances the production of H2O2 through oxygen reduction and collaborates with carbon nitride tubes to generate O2− and 1O2. Furthermore, carbon nitride tubes form electron-rich regions with lignin, promoting the transfer of electrons from adsorbed aromatic pollutants to this region, thereby facilitating their degradation. The experimental results indicate that the addition of 5 % lignin significantly enhances the photocatalytic degradation efficiency of azo dyes, with a degradation rate 1.87 times higher than that of the original carbon nitride tubes. Furthermore, CNL also have excellent degradation ability to pollutants in actual wastewater. This study provides new insights and prospects for the high-value utilization of lignin, enabling it to be used as a photocatalytic co-catalyst to participate in the photocatalytic degradation of environmental pollutants.

Photothermal Performance of Lignin-Based Nanospheres and Their Applications in Water Surface Actuators.

In this study, the photothermal performance of lignin-based nanospheres was investigated. Subsequently, a photothermal actuator was prepared using lignin-based carbon nanospheres (LCNSs). The results demonstrated that LCNSs exhibited an impressive photothermal conversion efficiency of up to 83.8%. This extreme efficiency significantly surpasses that of lignin nanospheres (LNSs) and covalently stabilized LNSs (HT-LNSs). As a structural material, a hydrophobic coating was effectively engineered by LCNSs on the filter paper, achieving a water contact angle of 151.9° ± 4.6°, while maintaining excellent photothermal effects (with a temperature increment from room temperature to 138 °C in 2 s). When employing hydrophobic filter paper as the substrate for the photothermaldriven actuator, under the influence of a 1.0 W/cm2 power-density NIR laser, the material exhibited outstanding photothermal actuation, achieving speeds up to 16.4 mm/s. In addition, the direction of motion of the actuator can be adjusted in accordance with the location of the NIR light irradiation. This study offers valuable perspectives on the application of LNSs for highvalue applications and the development of innovative photothermal-driven actuators.

Lignin-Based Nanospheres as Environmental Remediation Platforms for Anionic Dye Contaminants.

Modern manufacturing of textiles, pharmaceuticals, food, cosmetics, plastics, paper, etc. involves the utilization of anionic and cationic dyes that lead to significant water contamination. Recent research has explored the use of nanomaterials toward developing nanoadsorbents for water decontamination caused by industrial pollution. Here, we report on a novel platform for anionic dye remediation, consisting of a polyethylenimine-functionalized lignin nanosphere (PEI-LNS). The designed nanomaterial shows significant ability to adsorb an anionic dye selected as a proof-of-concept-Sulforhodamine B, from aqueous solutions. The PEI lignin nanoadsorbents (PEI-LNS) showed a better ability to adsorb Sulforhodamine B sodium salt (SBSS) when compared to the raw lignin nanosphere adsorbent (LNS), especially in acidic conditions. The nanomaterial was characterized through transmission electron microscopy, scanning electron microscopy, Brunauer-Emmett-Teller surface area analysis, elemental analysis, zeta potential, thermogravimetric analysis, Fourier transform infrared spectroscopy, and nuclear magnetic resonance. The impacts of ionic strength, contact time, pH, and adsorbent concentration have been evaluated. The ability of PEI-LNS to adsorb SBSS was found to be consistent with Langmuir isotherms and pseudo-second-order kinetic models. The PEI-LNS could be recycled three times, reaching a good (85%) adsorbing capacity even in the third cycle. The study demonstrates that PEI-LNS has a strong affinity as a novel adsorbent for anionic dyes and could be employed in environmental cleanups pertaining to such contaminations.

Organic solvent-free and high-productive fabrication of lignin nanospheres via soft templating and their mechanical enhancement on PVA hydrogels

Lignin nanoparticles, emerged as novel porous and functional materials, have attracted great attentions during the past decades. However, use of organic solvents and tedious solvent exchange processes restricted their scale-up production due to the concerns on environmental protection and sustainability. Here, we presented an organic solvent-free strategy to fabricate spherical lignin nanoparticles via soft templating and sol-gel-hydrothermal process in alkaline water media for the first time, in which technical soda lignin was precursor and both PEO−PPO−PEO triblock copolymers (P123) and sodium oleate (SO) acted as soft templates. Assisted by the P123/SO templates, lignin nanospheres (LHCS) were obtained with an average diameter of 190 nm, good dispersity and higher yield (63.29%, wt%). For valorization of prepared samples, lignin nanospheres were coated with tannin acid (TA@LHCS) and introduced into polyvinyl alcohol (PVA) hydrogels for enhancement their mechanical properties. The mechanical strength of the hydrogel was improved by the addition of TA@LHCS, endowing hydrogel with superior stretchability and compressibility. The maximum tensile strength of TA@LHCS enhanced PVA hydrogel reached 303.1 kPa, which was improved by three times. Therefore, this work provided a promising strategy for fabricating lignin nanoparticles via a facile method and broadened their valorizations in enhancing hydrogel strength.

Lignocellulosic biomass pretreatment with a lignin stabilization strategy and valorization toward multipurpose fractionation

Lignocellulosic biomass has emerged as a promising alternative with sustainable advantages for the production of a wide range of renewable products and value-added chemicals. In this study, a pretreatment strategy that use a fully recyclable acid hydrotrope (p-TsOH aqueous solution) to extract lignin and employ glyoxylic acid (GA) to stabilize lignin was proposed for biomass valorization toward multipurpose fractionation. 83.0 % of lignin was dissolved out by p-TsOH hydrotrope (80 wt%) with GA addition to form GA-stabilized product at 80 o C for 15 min. The stabilized lignin was subsequently used as an additive in the preparation of lignin-based suncream. Notably, the incorporation of 4 wt% lignin nanospheres into an SPF15 sunscreen yielded a measured SPF of 59.94. Furthermore, the depolymerization of uncondensed lignin into aromatic monomers yielded a high lignin-oil yield of 84.2 %. Additionally, direct heating of the pretreatment liquor facilitated the conversion of monosaccharides into furfural, achieving a desired yield of 53.7 % without the addition of any acid catalyst. The pretreatment also enhanced the enzymatic hydrolysis of glucan, resulting in a saccharification yield of 98.4 %. Moreover, short-term ultrasonication of the pretreated substrate yielded pulp suitable for papermaking. Incorporating 15 wt% fibers into the produced paper sheets led to a 5.3 % increase in tear index and a 25.4 % increase in tensile index. This study presents a viable pretreatment strategy for the multipurpose fractionation of lignocellulosic biomass, offering potential avenues for biomass valorization.

Fabrication modulation of lignin-derived carbon nanosphere supported Pd nanoparticle via lignin fractionation for improved catalytic performance in vanillin hydrodeoxygenation

Nano-lignin presents great potential in advanced carbon materials preparation since it integrates the advantages of nanomaterials as well the preferable properties of lignin (e.g. high carbon content and highly aromatic structure). Herein, lignin-derived carbon nanosphere supported Pd catalysts (Pd@LCNS) were prepared via a two-step carbonization of Pd2+ adsorbed lignin nanospheres (LNS) and applied in vanillin hydrodeoxygenation. The effect lignin heterogeneity on the synthesis of Pd@LCNS as well as its catalytic performance was further investigated through the synthesis of Pd@LCNS using three lignin fractions with different molecular weight. The results showed that the three Pd@LCNSs exhibited significant differences in the morphology of both carbon support and Pd nanoparticles. Pd@LCNS-3 prepared from high molecular weight lignin fraction (L-3) presented stable carbon nanosphere support with the smallest particle size (∼150 nm) and the highest Pd loading amount (3.78 %) with the smallest Pd NPs size (∼1.6 nm). Therefore, Pd@LCNS-3 displayed superior catalytic activity for vanillin hydrodeoxygenation (99.34 % of vanillin conversion and 99.47 % of 2-methoxy-4-methylphenol selectivity) at 90 °C without H2. Consequently, this work provides a sustainable strategy to prepare uniformly dispersed lignin-based carbon-supported Pd catalyst using high molecular weight lignin as the feedstock and further demonstrate its superior applicability in the selective transfer hydrogenation of vanillin.

Lewis acid/base mediated deep eutectic solvents intensify lignocellulose fractionation to facilitate enzymatic hydrolysis and lignin nanosphere preparation

In this work, Lewis acids (FeCl3, AlCl3) and bases (Na2CO3, Na2SO3) were incorporated into a neutral deep eutectic solvent (DES, choline chloride/glycerin) to intensify the lignocellulose fractionation. The efficiency of fractionation in terms of the maximum delignification rate (89.7 %) and well-pleasing cellulose saccharification (100 %) could be achieved by the Lewis acid-mediated DES. An in-depth insight of the evolution of lignin structure revealed that Lewis acid-mediated DES could cleave the β-O-4 linkages efficiently to achieve a high yield lignin fragments. Meanwhile, the lignin fragments with the enhanced amphiphilic properties facilitate the preparation of lignin nanospheres (LNSs) via the self-assembly process. The resultant LNSs extracted by Lewis acid-mediated DES exhibited an excellent thermal stability, and enhanced antibacterial capacity, which were associated with the phenolic OH content. However, the extracted lignin by Lewis base-mediated DES was mainly attributed to the cleavage of lignin-carbohydrate complexes bond, especially the lignin-carbohydrate ester bond, which retained more ether bonds and a relatively complete structure. This study illuminated the different mechanisms of lignin extraction and the structural evolution of lignin from Lewis acid/base-mediated DES, and provided guidance to select suitable fractionation techniques for upgrading the downstream products.

Pretreatment of corncob powder by choline chloride-urea-ethanolamine to co-produce glucose, xylose and lignin nanospheres

A ternary deep-eutectic solvents (DESs) which consisted of choline chloride-urea-ethanolamine (ChCl-U-EOA) was used for the pretreatment of corncob powder (CCP), and the effect of various pretreatment conditions on the pretreated substrates components and subsequent enzymatic digestion was investigated. The results indicated that under the optimum pretreatment conditions (110 ℃, 60 min, 10% solid concentration), the ChCl-U-EOA pretreatment could selectively remove ∼71.8% of lignin while retaining ∼87.7% of cellulose and ∼74.6% of hemicellulose, and the yields of glucose and xylose after enzymatic digestion reached ∼86.4% and ∼70.5%, respectively. The characterization of various pretreated substrates showed that the removal of lignin, and the fragmentation of pretreated substrates was the key factors to improve glucose/xylose yields. In addition, the lignin in the pretreated hydrolysate was collected by acid precipitation and fractionated by ethanol, and then lignin nanospheres (LNPs) with a particle size under 200 nm were fabricated via a solvent-antisolvent method.

Preparation of magnetic lignin-based adsorbents and its adsorption properties for dyes

In this study, the renewable magnetic lignin-based material with good properties and environmental friendliness was successfully prepared and used for the treatment of wastewater. Lignin nanospheres (LNS) were prepared from stearyl chloride esterified alkali lignin via self-assembly in the mixture and raspberry-like magnetic lignin microspheres (Fe3O4@SiO2-LNS) was successfully prepared by grafting LNS onto the surface of Fe3O4@SiO2 particles by chemical crosslinking, then was used as absorbent for Methylene blue (MB) and Rhodamine B (RhB) dyes. The results indicated that the Fe3O4@SiO2-LNS had excellent adsorptivity in alkaline solution, and the maximum adsorption capacities for MB and RhB were 258.40 mg·g-1 and 124.38 mg·g-1 , respectively. The Fe3O4@SiO2-LNS adsorbent can be recycled due to its good magnetism and the regeneration efficiency is over 85% after three cycles. Therefore, the prepared magnetic lignin-based adsorbent is a lowcost, high-efficiency and reusable adsorbent for wastewater treatment.

Fully upgrade lignocellulose to three nanomaterials by combinational pretreatment: Refining straw waste to pesticide nanocarrier

To achieve the maximum value from lignocellulosic biomass, an integrated biorefinery based on molecule-level design is required. In this study, a combination of hydrothermal pretreatment (HTP) coupling deep eutectic solvent (DES) pretreatment was proposed to produce three upgraded products, namely hemicellulose-derived activated nanocarbon (ANC), lignin nanosphere (LNS), and lignin-containing cellulose nanofiber (LCNF) pesticide nanocarrier, from rice straw. The hydrothermal filtrate, which consists of 100% hemicellulose, was converted into value-added nanocarbon by in-situ carbon sequestration. The upgraded nanocarbon exhibited an excellent specific surface area (2692.3 m2 g−1) and a high degree of graphitization, which value-added attributes could increase revenue to integrated biorefinery. The subsequent DES extraction increased the phenolic –OH content and further aggregated the lignin condensed structure, which facilitated lignin nanosphere preparation by the self-assembly process. Meanwhile, the DES swelling of cellulose facilitated the nanofibrillation of LCNF, which was used as a pesticide carrier to improve pesticide utilization efficiency by simple cationic modification. The residual lignin with functional groups facilitated the crosslinking between the lignin fragments and cellulose fibers by hydrogen bonding interactions, which endowed LNCF highly entangled network and unique lignin properties. The functionalized LCNF exhibited enhanced adhesion and unique anti-UV ability for pesticide deposition and retention. This work realized the all-components upgrading of lignocellulose and inspired the development of sustainable and viable biorefineries.