Abstract This research examines recycling potassium hydroxide-based pretreatment black liquor in wheat straw chemi-thermo-mechanical pulping (CTMP) to improve process sustainability and cut operational expenses. By reusing the black liquor across five cycles, the solid content increased from 6.2 % to 14.8 %, concentrating both organic and inorganic elements without adding new chemicals. About 80 % of the solids were degradation products of cellulose, hemicellulose, and lignin, with potassium and silicon making up the remaining 20 %. The recycling did not harm fiber structure, pulp strength, or papermaking ability, as shown by FTIR, SEM, and Micro-CT analyses. No new functional groups appeared, though slight increases in hydroxyl and carbonyl bands were noticed. These findings reveal that black liquor recycling in wheat straw CTMP is a viable method to boost liquor concentration, reduce freshwater use, and lower energy and costs associated with evaporation and transportation. This study supports cleaner production in non-wood pulping by enabling effluent reuse and valorization within a circular process.

The flammability of most decorative paper poses a potential fire hazard to buildings. In this study, softwood fibers were modified with phytic acid and urea to obtain phytic acid esterified cellulose (PAEC) with good flame-retardant properties. Due to the introduction of phosphorus and nitrogen elements in PAEC, the heat release rate (HRR) and total heat release (THR) decreased from 170.9 W/g and 7.6 kJ/g to 104.3 W/g and 4.9 kJ/g, respectively, when compared with raw fibers. Subsequently, PAEC was composited with talc powder, carboxylated nanofibers, and calcium ions to prepare flame retardant paper. The results indicated that the HRR of the 170.9 W/g of the paper was decreased to 47.0 W/g. The network structure formed by the cross-linking between carboxyl groups in nanofibers and Ca2⁺ enhanced the paper’s mechanical properties. The strength reached 12.18 MPa, which was 1.4 times as high as that of raw paper. Therefore, the prepared flame-retardant paper is expected to provide a candidate for the preparation of decorative paper.

Passive daytime radiative cooling is an electricity-free cooling technology that radiates sunlight and radiates heat to cold space. However, traditional radiation cooling materials are facing many challenges, such as poor mechanical properties or non-flame retardancy. Herein, a flame-retardant porous radiative cooling polyurethane and cellulose acetate composite film with excellent mechanical properties was successfully designed and constructed. The porous structure was achieved by low boiling point solvent volatilization and high boiling point solvent displacement. The resulting film exhibits high solar reflectivity (98.2%), high infrared emissivity (94.3%), and excellent mechanical properties (13.2 MPa). Also, it can effectively cool down 15.6 degrees C in an outdoor environment with 900 W m-2 sunlight radiation. In addition, good flame-retardant and color aesthetic properties facilitate their application as building materials to achieve high efficiency and energy conservation. Therefore, this work provides an approach for radiative cooling in a complex environment.

Developing the coating with superior waterproofing and heat dissipation abilities can prevent electronics from contamination and heat damage. However, most of these coatings show poor transparency and antifouling ability. In this study, a multifunctional ultra-slippery transparent coating (STC) has been developed by simply spraying suspensions consisting of poly(perfluorodecyl acrylate-co-isobornyl acrylate) followed by the curing treatment at room temperature. The thickness of the coating is only 1.5 mu m measured by scanning electron microscope. A high transparency of 90 % is observed by UV-vis-NIR. X-ray photoelectron spectroscopy and fourier transform infrared spectroscopy demonstrate successful formation of STC and explain low surface energy. The slippery surface makes the rapid sliding of water and oil droplets when tilted at only 8 degrees. The surface of the coating can be cleaned by water and oil-based liquids due to its excellent slippery property. In addition, the heat dissipation of electronic devices was improved after coating STC. High transparency makes it easier to observe the working condition of precision equipment. Also, the STC protects the electronic components from short circuit destroying during for underwater operation. Therefore, the prepared STC shows great promise for various electronic devices due to its easy fabrication and versatile performance.

The PVA film usually absorbs moisture from the environment due to its good water solubility, which results in a decrease in mechanical strength, thereby limiting the application of PVA films in plastics. In this study, modified PVA with vanillin was combined with carboxylated lignin to prepare polyvinyl alcohol/carboxylated lignin composites (VPVAL@Ca) by a crosslink reaction with calcium ions. The composite film demonstrated good hydrophobicity with a water contact angle of 95°. The mechanical strength was improved with a tensile strength of 90.1 MPa and fracture strain of 16 %. Additionally, the material demonstrated excellent UV resistance, effectively blocking UVB and UVC rays while shielding most of the UVA. When VPVAL@Ca was used as a coating material for paper, the coated paper exhibited superior barrier properties with a water contact angle of 92°, oil resistance of KIT 12, a Cobb120 value of 5.4 g/m2, and an oxygen permeability of only 0.7 cm3/(m2·24h·0.1 MPa). Furthermore, the VPVAL@Ca paper composite material displayed good biodegradability in soil, with nearly complete degradation after 36 days. This study presents a novel approach for developing high-performance biodegradable materials and enhancing the value of PVA and lignin.

As a precursor, caproate is widely used in food and medicine for production of various valuable products. From an environmental point of view, caproate production by anaerobic fermentation is a sustainable way. The cost of caproate could be reduced if the wasted biomass is used as substrate. In this study, the caproate production from corn straw and food waste was investigated. Results showed that the sulfuric acid - enzyme method was the optimum approach for hydrolysis of corn straw, and the corresponding glucose concentration was 24.3 g/L. At the optimum condition, the 5-hydroxymethyl furfural (HMF) was found to be the main inhibitor of the hydrolysate, which exhibited inhibitory effect to ethanol and caproate fermentation. Further analysis showed that the inhibition threshold of HMF to Clostridium kluyveri was 1.2 g/L. The formation of biofilm in the fermentation system was found to be an effective way for improving the robustness of cells to inhibitors. The caproate production of 13.5 g/L was obtained when the ethanol and acetate derived from corn straw and food waste was used as substrates. This study cast an insight that it was a promising way for caproate production from the corn straw and food waste.

Lithium bromide molten salt hydrate (∼62 wt% aqueous solution of LiBr) can dissolve cellulose, but the cellulose dissolution mechanisms are not fully understood. This study revisited cellulose dissolution in the LiBr solution and aimed to provide new insights into the dissolution mechanisms. The collected evidence suggested that cellulose dissolution in the LiBr solution is primarily attributed to the disruption of intermolecular H-bonds of cellulose by the ion-dipole coordination between hydrated Li+ and cellulose hydroxy. The coordination between Li+ and cellulose was verified by 7Li NMR and simultaneous DSC-TGA analysis. The observations in this study also suggest that polarizable, large-size, and low-electronegativity Br– plays a synergetic and supplementary role in the dissolution of cellulose. In addition, the dissolution of cellulose in the LiBr solution is greatly dependent on dissolution conditions (LiBr concentration, temperature, pH, and cellulose loading) and cellulose properties (particle size and degree of polymerization).

Heavy metal ions and dyes in wastewater pose a severe hazard to ecological system and human health. This study used sulfamic acid (SA) to modify cellulose for adsorbent material preparation. The results from the structural characterization indicated that cellulose was successfully modified by introducing sulfonic acid groups to obtain sulfamic acid modified cellulose (SAMC). Subsequently, SAMC was prepared into spheres via being dissolved in ionic liquid and obtaining in antisolvent. The adsorption performance of SAMC aerogel spheres was investigated using methylene blue (MB) and lead ions (Pb2+). The maximum absorption capacity of SAMC aerogel spheres to MB and Pb2+ achieved 14.53 mg/g and 112.15 mg/g, respectively. The adsorption process conformed to the pseudo-second-order (PSO) model and Langmuir model. The adsorption mainly involved chemical action via coordination interaction between -SO32− and MB/Pb2+. Thermodynamic experiments confirmed that the adsorption process in the experiment was a spontaneous endothermic process. Therefore, this study provided a simple adsorbent production method for wastewater treatment.

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.

Natural lignin has been considered a promising additive for ultraviolet (UV) protection cosmetics applications. Nevertheless, its potential application in cosmetics production is impeded by its inherent dark coloration due to structural damage incurred during the industrial lignin extraction process. In this study, glyoxylic acid (GA) was used to prevent lignin condensation during lignin extraction using an acid recycled hydrotrope (p-toluenesulfonic acid, p-TsOH). Further processing of the GA stabilized lignin yielded lignin nanospheres (LNPs) for a natural sunscreen additive. Incorporating 3% and 4% LNPs into a baseline SPF10 commercial sunscreen resulted in lignin-based sunscreen with SPF values of 37.2 ± 2.55 and 58.74 ± 2.14, respectively. These exceeded the SPF levels observed in commercial sunscreens with SPF30 and SPF50. Furthermore, the pretreated cellulose residue was utilized in the production of pulp fibers for papermaking. It was observed that the ring crush strength index of the paper, achieved by incorporating 15 wt % fibers into softwood pulp, reached a notable value of 2.98 ± 0.10 N·m/g. The tear index and tensile index of the produced paper, augmented with a 5 wt % addition of fibers, were as high as 4.77 ± 0.41 mN·m2/g and 9.49 ± 0.27 N·m/g, respectively. Therefore, a new strategy for stabilized lignin extraction and lignocellulose biomass valorization was proposed in this study.

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 ligninoil 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.

This study synthesized a functional deep eutectic solvent (DES) using betaine and glyoxylic acid (GA) for lignocellulosic biomass pretreatment. The Betaine/GA DES pretreatment resulted a high delignification efficiency of 81.89% and xylan removal of 83.25% while preserving most of cellulose. During pretreatment, lignin was stabilized by GA, preventing its condensation and introducing carboxyl groups onto its molecular backbone. The GA stabilized lignin (GASL), with a high beta-O-4 linkage content of 62.92%, was depolymerized for phenolic monomer production with a bio-oil yield of 55.40%. Additionally, the functional lignin was used as a surfactant for GASL-based O/W emulsion (GA-O/W emulsion) preparation. With 0.5% of lignin addition and an optimal O/ W ratio of 6:4, the resulting GA-O/W emulsion exhibited a high cream index value of 100% and excellent storage stability without any phase transition or emulsion aggregation. When using the lignin to prepare curcuminencapsulated microcapsules, a cumulative curcumin remaining of 74.19% under UV radiation and an extraordinary encapsulation efficiency of 62.86% were achieved. Furthermore, this DES pretreatment promoted enzymatic saccharification of the pretreated cellulose substrate, resulting in a glucose yield of 91.49%. After adding 15 wt% of the fibers in soft wood pulp for papermaking, the tear index, ring crush strength index, and tensile index of the produced paper-sheets reached 112.04%, 98.58%, and 83.55% of those of the pure softwood pulp papers, respectively.

The pretreatment of lignocellulosic biomass with a functional DES that incorporates choline chloride (ChCl) and glyoxylic acid (GA) resulted in a high removal of lignin and hemicellulose, lignin stabilization, and cellulose functionalization.

In this study, biomass-derived organic solvents (GVL, THF, and ethanol) were used to pretreat lignocellulosic biomass to facilitate the extraction of lignin and enzymatic hydrolysis of glucan. Under the same pretreatment conditions (120 °C, 30 min, 0.5 wt

Cellulose as a moisture sensing material had been successfully used in preparation of fiber optic relative humidity sensors (FORHSs) to monitor the humidity of external environment. However, the sensitivity of cellulose to humidity response needs to be further improved. Based on it, sulfamic acid esterified cellulose (SAEC) was fabricated to be a moisture sensitive material for FORHS preparation. The produced SAEC exhibited a good hygroscopicity and dehumidification stability (the standard deviation of weight changes, σ = 0.0035) and high moisture absorption (121

Abstract Background As one of the most abundant bioresource in nature, the value-added utilization of lignocellulosic biomass is limited due to its inherent stubbornness. Pretreatment is a necessary step to break down the recalcitrance of cell walls and achieve an efficient separation of three main components (cellulose, hemicelluloses, and lignin). Results In this study, hemicelluloses and lignin in Boehmeria nivea stalks were selectively extracted with a recyclable acid hydrotrope, an aqueous solution of P-toluenesulfonic acid (p-TsOH). 79.86% of hemicelluloses and 90.24% of lignin were removed under a mild pretreatment condition, C80T80t20, (acid concentration of 80 wt%, pretreatment temperature and time of 80 °C and 20 min, respectively). After ultrasonic treatment for 10 s, the residual cellulose-rich solid was directly converted into pulp. Subsequently, the latter was utilized to produce paper via mixing with softwood pulp. The prepared handsheets with a pulp addition of 15 wt% displayed higher tear strength (8.31 mN m2/g) and tensile strength (8.03 Nm/g) than that of pure softwood pulp. What’s more, the hydrolysates of hemicelluloses and the extracted lignin were transformed to furfural and phenolic monomers with yields of 54.67% and 65.3%, respectively. Conclusions The lignocellulosic biomass, Boehmeria nivea stalks, were valorized to pulp, furfural, and phenolic monomers, successfully. And a potential solution of comprehensive utilization of Boehmeria nivea stalks was provided in this paper. Graphical Abstract

Lignin has a UV-blocking ability because it contains phenolic and ketone functional groups. However, the lignin produced in the paper industry undergoes extreme polycondensation, resulting in an extremely dark color, which impedes its value-added application in the field of UV-blocking cosmetics. In this study, maleic acid (MA) was used as a green and recyclable reagent to pretreat an agricultural waste lignocellulosic biomass, Kenaf stalk. Lignin underwent a carboxyl esterification reaction with MA to produce light-colored dissolved lignin (DL), which was further prepared into lignin nanospheres and used in lignin-based sunscreens. The results showed that when adding 5 wt

Burning corncob for energy requirements caused a huge waste of biomass resources and serious environment pollution. Herein, this study provided a high-value utilization strategy for corncob. Corncob was first pretreated by hydrothermal process. The collected hydrolysates were converted into furfural by a recyclable solid acid with a yield of 52.35

传统工艺在木质纤维生物质的转化利用中表现出较低的效率,极大地限制了生物质资源的高值化利用,而锂盐溶剂体系在木质纤维的高效转化及应用中显示出巨大潜力.本文介绍了锂盐溶剂体系的性质,综述了锂盐溶剂体系在木质纤维类生物质转化及利用过程中的研究进展,重点分析了在纤维素衍生物的制备、葡萄糖的高效转化、平台化合物的制备和生物炭的制备上的作用.同时,归纳了目前锂盐溶剂体系下木质纤维利用存在的问题,并对未来的研究方向提出了建议.

Lignin has been regarded as a potential natural sun screening agent. However, the dark color of traditional industrial lignin hinders its application in the field of skincare. In this study, a green and facile approach was developed to extract light-colored lignin. p-Toluenesulfonic acid (p-TsOH) was used to separate lignin and fibers from Kenaf stalks. During the isolation of lignin, formaldehyde was added to preserve the β-O-4 bonds of lignins in the form of stable acetals. The obtained lignin was further employed to prepare nanoparticles (LNPs) as sunscreen additives. After adding 4 wt% LNPs, the SPF values of the cream increased from 7.05 to 27.84. The residual fibers from the Kenaf stalks can be utilized for papermaking as the raw materials. by mixing them with softwood pulp to reduce the consumption of commercial pulp. With the addition of 5 wt% residual fibers in commercial softwood pulp, the produced paper showed better mechanical properties. The ring crush strength index and tear index of the samples increased from 2.49 N·m/g and 4.63 mN·m2/g to 2.62 N·m/g and 4.75 mN·m2/g, respectively. This study paved a way for the comprehensive utilization of Kenaf stalks towards not only papermaking but also daily chemical products.