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1.
Small ; 20(17): e2307344, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38133516

RESUMEN

The intrinsic poor rheological properties of MXene inks result in the MXene nanosheets in dried MXene microfibers prone to self-stacking, which is not conducive to ion transport and diffusion, thus affecting the electrochemical performance of fiber-based supercapacitors. Herein, robust cellulose nanofibrils (CNF)/MXene hybrid fibers with high electrical conductivity (916.0 S cm-1) and narrowly distributed mesopores are developed by wet spinning. The interfacial interaction between CNF and MXene can be enhanced by hydrogen bonding and electrostatic interaction due to their rich surface functional groups. The interfacial modulation of MXene by CNF can not only regulate the rheology of MXene spinning dispersion, but also enhance the mechanical strength. Furthermore, the interlayer distance and self-stacking effect of MXene nanosheets are also regulated. Thus, the ion transport path within the fiber material is optimized and ion transport is accelerated. In H2SO4 electrolyte, a volumetric specific capacitance of up to 1457.0 F cm-3 (1.5 A cm-3) and reversible charge/discharge stability are demonstrated. Intriguingly, the assembled supercapacitors exhibit a high-volume energy density of 30.1 mWh cm-3 at 40.0 mW cm-3. Moreover, the device shows excellent flexibility and cycling stability, maintaining 83% of its initial capacitance after 10 000 charge/discharge cycles. Practical energy supply applications (Power for LED and electronic watch) can be realized.

2.
Langmuir ; 2024 Jul 18.
Artículo en Inglés | MEDLINE | ID: mdl-39023123

RESUMEN

Graphitic carbon nitride (g-C3N4), since the pioneering work on visible-light photocatalytic water splitting in 2009, has emerged as a highly promising advanced material for environmental and energetic applications, including photocatalytic degradation of pollutants, photocatalytic hydrogen generation, and carbon dioxide reduction. Due to its distinctive two-dimensional structure, excellent chemical stability, and distinctive optical and electrical properties, g-C3N4 has garnered a considerable amount of interest in the field of biomedicine in recent years. This review focuses on the fundamental properties of g-C3N4, highlighting the synthesis and modification strategies associated with the interfacial structures of g-C3N4-based materials, including heterojunction, band gap engineering, doping, and nanocomposite hybridization. Furthermore, the biomedical applications of these materials in various domains, including biosensors, antimicrobial applications, and photocatalytic degradation of medical pollutants, are also described with the objective of spotlighting the unique advantages of g-C3N4. A summary of the challenges faced and future prospects for the advancement of g-C3N4-based materials is presented, and it is hoped that this review will inspire readers to seek further new applications for this material in biomedical and other fields.

3.
Nano Lett ; 22(9): 3784-3792, 2022 May 11.
Artículo en Inglés | MEDLINE | ID: mdl-35486490

RESUMEN

Silver nanowires (AgNWs) have been considered as a promising candidate for transparent stretchable conductors (TSCs). However, the strong interface mismatch of stiff AgNWs and elastic substrates leads to the stress concentration at their interface and ultimately the low stretchability and poor durability of TSCs. Here, to address the interfacial mismatch of AgNWs-based TSCs we put forward a universal interface tailoring strategy that introduces the mercapto compound as the intermediate cross-linked layer. The mercapto compound strongly interacts with the AgNWs, forming a dense protective layer on their surface to improve their corrosion resistance, and reacts with the polymer substrate, forming a buffer layer to release the concentrated stress. As a result, the optimized TSCs showed superior stretchability (160%), exceptional durability (230 000 cycles), competent optoelectrical performance (18.0 ohm·sq-1 with a transmittance of 86.5%), and prominent stability. This work provides clear guidance and a strong impetus for the development of transparent stretchable electronics.

4.
Molecules ; 25(11)2020 Jun 03.
Artículo en Inglés | MEDLINE | ID: mdl-32503303

RESUMEN

In this work, lignin fractionation is proposed as an effective approach to reduce the heterogeneity of lignin and improve the adsorption and recycle performances of lignin as a cationic dye adsorbent. By stepwise dissolution of enzymatic hydrolysis lignin in 95% and 80% ethanol solutions, three lignin subdivisions (95% ethanol-soluble subdivision, 80% ethanol-soluble subdivision, and 80% ethanol-insoluble subdivision) were obtained. The three lignin subdivisions were characterized by gel permeation chromatography (GPC), FTIR, 2D-NMR and scanning electron microscopy (SEM), and their adsorption capacities for methylene blue were compared. The results showed that the 80% ethanol-insoluble subdivision exhibited the highest adsorption capacity and its value (396.85 mg/g) was over 0.4 times higher than that of the unfractionated lignin (281.54 mg/g). The increased adsorption capacity was caused by the enhancement of both specific surface area and negative Zeta potential. The maximum monolayer adsorption capacity of 80% ethanol-insoluble subdivision by adsorption kinetics and isotherm studies was found to be 431.1 mg/g, which was much higher than most of reported lignin-based adsorbents. Moreover, the 80% ethanol-insoluble subdivision had much higher regeneration yield (over 90% after 5 recycles) compared with the other two subdivisions. Consequently, the proposed fractionation method is proved to be a novel and efficient non-chemical modification approach that significantly improves adsorption capacity and recyclability of lignin.


Asunto(s)
Cationes/aislamiento & purificación , Celulasa/metabolismo , Fraccionamiento Químico/métodos , Etanol/química , Lignina/metabolismo , Azul de Metileno/aislamiento & purificación , Agua/química , Adsorción , Cationes/análisis , Lignina/química , Lignina/aislamiento & purificación , Azul de Metileno/análisis
5.
Nutr Cancer ; 71(1): 149-158, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30633592

RESUMEN

This study evaluated the antitumor activity of the extracts of green husks of Juglans sigillata Dode on esophageal cancer. KYSE150 EC9706 cells were treated with different concentrations of six components of the extracts of J. sigillata green husks. Cell viability was measured by MTT. Cell migration and cell invasion were measured by wound-healing assays and transwell assays, respectively. Cell apoptosis and cycle were measured by flow cytometry. The expression of cell migration, cell cycle and cell apoptosis regulatory proteins was analyzed by Western blotting. Only the three constituents, including EtOH extractives, EtOAc soluble fraction and gallic acid (GA), exhibited inhibitory effects on the cell viability, migration and invasion by decreasing MMP2 and MMP9 expression (all P < 0.05). Flow cytometry revealed that these three constituents also induced cell apoptosis by increasing Bax and cleaved caspase-3 but decreasing Bcl-2 in KYSE150 and EC9706 cells. Furthermore, these constituents arrested the cell cycle at G0/G1 by downregulating the expression of Cyclin D1 but upregulating p53 and phospho-p53 expression in KYSE150 cells. In conclusion, the green husks of J. sigillata may act as a potential inhibitor on esophageal cancer growth. GA was the major single active constituent of the extracts.


Asunto(s)
Antineoplásicos Fitogénicos/farmacología , Neoplasias Esofágicas/tratamiento farmacológico , Juglans , Extractos Vegetales/farmacología , Apoptosis/efectos de los fármacos , Ciclo Celular/efectos de los fármacos , Línea Celular Tumoral , Movimiento Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Neoplasias Esofágicas/patología , Ácido Gálico/farmacología , Humanos
6.
Int J Mol Sci ; 19(2)2018 Feb 23.
Artículo en Inglés | MEDLINE | ID: mdl-29473838

RESUMEN

Panax ginseng has high medicinal and health values. However, the various and complex components of ginseng may interact with each other, thus reducing and even reversing therapeutic effects. In this study, we designed and fabricated a novel "nano-ginseng" with definite ingredients, ginsenoside Rb1/protopanaxadiol nanoparticles (Rb1/PPD NPs), completely based on the protopanaxadiol-type extracts. The optimized nano-formulations demonstrated an appropriate size (~110 nm), high drug loading efficiency (~96.8%) and capacity (~27.9 wt %), long half-time in systemic circulation (nine-fold longer than free PPD), better antitumor effects in vitro and in vivo, higher accumulation at the tumor site and reduced damage to normal tissues. Importantly, this process of "nano-ginseng" production is a simple, scalable, green economy process.


Asunto(s)
Panax/química , Sapogeninas/farmacología , Animales , Antineoplásicos/farmacología , Muerte Celular/efectos de los fármacos , Línea Celular Tumoral , Femenino , Hemólisis/efectos de los fármacos , Concentración de Iones de Hidrógeno , Cinética , Ratones Endogámicos C57BL , Nanopartículas/química , Nanopartículas/ultraestructura , Extractos Vegetales/farmacología , Sapogeninas/química , Sapogeninas/farmacocinética , Distribución Tisular
7.
Int J Mol Sci ; 17(3): 315, 2016 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-26938526

RESUMEN

For the first time, a pale amorphous coumarin derivative, 5-methoxyl aesculetin (MOA), was isolated from the dried bark of Fraxinus rhynchophylla Hance (Oleaceae). MOA modulates cytokine expression in lipopolysaccharide (LPS)-treated RAW 264.7 macrophages, but the precise mechanisms are still not fully understood. We determined the effects of MOA on the production of inflammatory mediators and pro-inflammatory cytokines in the LPS-induced inflammatory responses of RAW 264.7 macrophages. MOA significantly inhibited the LPS-induced production of nitric oxide (NO), prostaglandin E2 (PGE2), tumor necrosis factor-α (TNF-α), interleukin-6, and interleukin-1ß. It also effectively attenuated inducible nitric oxide (NO) synthase, cyclooxygenase-2, and TNF-α mRNA expression and significantly decreased the levels of intracellular reactive oxygen species. It inhibited phosphorylation of the extracellular signal-regulated kinase (ERK1/2), thus blocking nuclear translocation of activation protein (AP)-1. In a molecular docking study, MOA was shown to target the binding site of ERK via the formation of three hydrogen bonds with two residues of the kinase, which is sufficient for the inhibition of ERK. These results suggest that the anti-inflammatory effects of MOA in RAW 264.7 macrophages derive from its ability to block both the activation of mitogen-activated protein kinases (MAPKs) and one of their downstream transcription factors, activator protein-1 (AP-1). Our observations support the need for further research into MOA as a promising therapeutic agent in inflammatory diseases.


Asunto(s)
Antioxidantes/farmacología , Sistema de Señalización de MAP Quinasas , Macrófagos/efectos de los fármacos , Factor de Transcripción AP-1/metabolismo , Umbeliferonas/farmacología , Animales , Línea Celular , Ciclooxigenasa 2/genética , Ciclooxigenasa 2/metabolismo , Dinoprostona/metabolismo , Interleucinas/genética , Interleucinas/metabolismo , Lipopolisacáridos/toxicidad , Macrófagos/metabolismo , Ratones , Proteína Quinasa 1 Activada por Mitógenos/metabolismo , Proteína Quinasa 3 Activada por Mitógenos/metabolismo , Óxido Nítrico/metabolismo , Factor de Necrosis Tumoral alfa/genética , Factor de Necrosis Tumoral alfa/metabolismo
8.
Int J Biol Macromol ; 258(Pt 2): 129046, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38154714

RESUMEN

Constructing a high-performance ultraviolet shielding film is an effective way for addressing the growing problem of ultraviolet radiation. However, it is still a great challenge to achieve a combination of multifunctional, excellent mechanical properties and low cost. Here, inspired by the multiscale structure of biomaterials and features of lignin, a multifunctional composite film (CNF/CMF/Lig-Ag) is constructed via a facile vacuum-filtration method by introducing micron-sized cellulose fibers (CMF) and lignin-silver nanoparticles (Lig-Ag NPs) into the cellulose nanofibers (CNF) film network. In this composite film, the microfibers interweave with nanofibers to form a multiscale three-dimensional network, which ensures satisfactory mechanical properties of the composite film. Meanwhile, the Lig-Ag NPs are employed as a multifunctional filler to enhance the composite film's antioxidant, antibacterial and ultraviolet shielding abilities. As a result, the prepared CNF/CMF/Lig-Ag composite film demonstrates excellent mechanical properties (with tensile strength of 133.8 MPa and fracture strain of 7.4 %), good biocompatibility, high thermal stability, potent antioxidant and antibacterial properties. More importantly, such composite film achieves a high ultraviolet shielding rate of 98.2 % for ultraviolet radiation A (UVA) and 99.4 % for ultraviolet radiation B (UVB), respectively. Therefore, the prepared CNF/CMF/Lig-Ag composite film shows great potential in application of ultraviolet protection.


Asunto(s)
Lignina , Nanopartículas del Metal , Lignina/química , Celulosa/química , Plata/química , Antioxidantes , Rayos Ultravioleta , Nanopartículas del Metal/química , Antibacterianos
9.
Food Chem ; 458: 140329, 2024 Jul 03.
Artículo en Inglés | MEDLINE | ID: mdl-38991239

RESUMEN

Recently, fiber-based and functional paper food packaging has garnered significant attention for its versatility, excellent performance, and potential to provide sustainable solutions to the food packaging industry. Fiber-based food packaging is characterized by its large surface area, adjustable porosity and customizability, while functional paper-based food packaging typically exhibits good mechanical strength and barrier properties. This review summarizes the latest research progress on food packaging based on fibers and functional paper. Firstly, the raw materials used for preparing fiber and functional paper, along with their physical and chemical properties and roles in food packaging, were discussed. Subsequently, the latest advancements in the application of fiber and paper materials in food packaging were introduced. This paper also discusses future research directions and potential areas for improvement in fiber and functional paper food packaging to further enhance their effectiveness in ensuring food safety, quality, and sustainability.

10.
Int J Biol Macromol ; 258(Pt 2): 128963, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38154721

RESUMEN

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.


Asunto(s)
Benzaldehídos , Carbono , Nanosferas , Carbono/química , Lignina/química , Hidrogenación
11.
Int J Biol Macromol ; 258(Pt 1): 128640, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38061515

RESUMEN

Pectin-crosslinked gum ghatti hydrogel (PGH) has been synthesized utilizing pectin and gum ghatti through an uncomplicated and inexpensive copolymerization method. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM-elemental mapping), Brunauer-Emmett-Teller (BET), and X-ray photoelectron spectroscopy (XPS) characterization techniques have been employed to determine various structural, chemical and compositional characteristics of fabricated PGH. Three different weight ratios (1:1, 2:1, or 1:2 for pectin and gum ghatti, respectively) were employed to synthesize three distinct types of PGH. Swelling studies has been done to determine the best ratios for PGH fabrication. PGH has been assessed as an adsorbent for the removal of malachite green dye from aqueous solutions. The effects of PGH dosage (100-400 mg/L), dye concentration (10-160 mg/L), pH (2-9 pH), adsorption time (0-480 min), and temperature (25-55 °C) has been examined through batch solutions. According to Langmuir isotherm analysis, the maximum adsorption capacity is 658.1 mg/g. By using pseudo-second-order kinetics and the Freundlich adsorption isotherm, the adsorption process could be well explained. After five consecutive cycles, PGH had an adsorption percentage of 86.917 % for the malachite green dye. It is safe for the environment and may be used to remove malachite green (MG) dye from aqueous solutions.


Asunto(s)
Hidrogeles , Gomas de Plantas , Colorantes de Rosanilina , Contaminantes Químicos del Agua , Hidrogeles/química , Adsorción , Pectinas , Espectroscopía Infrarroja por Transformada de Fourier , Cinética , Concentración de Iones de Hidrógeno , Contaminantes Químicos del Agua/química
12.
Adv Mater ; 36(32): e2403876, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38739951

RESUMEN

Sorption-based atmospheric water harvesting is an attractive technology for exploiting unconventional water sources. A critical challenge is how to facilitate fast and continuous collection of potable water from air. Here, a bio-based gel (cellulose/alginate/lignin gel, CAL gel), resulting from the integration of a whole biomass-derived polymer network with lithium chloride is reported. A fast adsorption/desorption kinetics, with a water capture rate of 1.74 kg kg-1 h-1 at 30% relative humidity and a desorption rate of 1.98 kg kg-1 h-1, is simultaneously realized in one piece of CAL gel, because of its strong hygroscopicity, hydrophilic network, abundant water transport channels, photothermal conversion ability, and ≈200-µm-thick self-supporting bulky structure caused by multicomponent synergy. A solar-driven, drum-type, tunable, and portable harvester is designed that can harvest atmospheric water within a brief time. Under outdoor conditions, the harvester with CAL gels operates 36 switches (180°) per day realizes a water yield of 8.96 kg kggel -1 (18.87 g kgdevice -1). This portable harvester highlights the potential for fast and scalable atmospheric water harvesting in extreme environments.

13.
Carbohydr Polym ; 336: 122109, 2024 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-38670767

RESUMEN

Pulp and paper are gradually transforming from a traditional industry into a new green strategic industry. In parallel, cellulose-derived transparent paper is gaining ground for the development of advanced functional materials for light management with eco-friendly, high performance, and multifunctionality. This review focuses on methods and processes for the preparation of cellulose-derived transparent papers, highlighting the characterization of raw materials linked to responses to different properties, such as optical and mechanical properties. The applications in electronic devices, energy conversion and storage, and eco-friendly packaging are also highlighted with the objective to showcase the untapped potential of cellulose-derived transparent paper, challenging the prevailing notion that paper is merely a daily life product. Finally, the challenges and propose future directions for the development of cellulose-derived transparent paper are identified.

14.
Int J Biol Macromol ; 262(Pt 1): 130017, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38336333

RESUMEN

Sustainably sourced lignin presents great potential as a green feedstock for fertilizer production but commercial fulfillment is still challenging owing to the mediocre fertilizer activity of lignin. To address this issue, an effective strategy to enhance the activity of lignin-based potassium fertilizer (LPF) is proposed through lignin fractionation. Three lignin fractions subdivided from enzymatic hydrolysis lignin (EHL) were adopted as the feedstock for LPF preparation, and the effect of lignin fractionation on wheat seed germination and seedling growth was investigated. Compared with the potassium fertilizer from unfractionated lignin, LPF-F1 showed significantly improved effects on promoting seed germination and seedling growth, which can be attributed to the high potassium content resulted from its abundant phenolic hydroxyl and carboxyl contents. Under the optimal treatment concentration (100 mg/L), LPF-F1 showed comparable promotion effect to commercial fulvic acid potassium on wheat seedling growth, suggesting the potential of LPF-F1 as commercial potassium fertilizer. Overall, this work reveals that lignin heterogeneity presents critical effects on the wheat seed germination and seedling growth of LPF, and the fertilizer activity of LPF can be substantially improved using fractionated lignin with low molecular weight as the raw material.


Asunto(s)
Lignina , Plantones , Lignina/farmacología , Germinación , Triticum , Fertilizantes , Hidrólisis , Semillas
15.
Chemosphere ; 352: 141365, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38331267

RESUMEN

Microplastics (MPs), as emerging pollutants, have attracted the attention of environmentalists, statespersons, and the scientific community over the last few decades. To address the spread of MPs in the environment, it is imperative to develop various removal techniques and materials that are effective, scalable, and ecologically benign. However, to the best of our knowledge, no review has systematically examined the removal of MPs using adsorption or provided an in-depth discussion on various adsorbents. Adsorption is an inexpensive and effective technology for wastewater treatment. Recently, many researchers have conducted studies on MP remediation using diverse adsorbent materials, such as biochar, activated carbon, sponges, carbon nanotubes, metal-layered oxides, metal-organic frameworks (MOFs), and zeolites. Each adsorbent has advantages and disadvantages. To overcome their disadvantages, researchers have been designing and developing hybrid adsorbents for MP remediation. This review provides insights into these individual adsorbents and also discusses hybrid adsorbents for MP removal. Finally, the review elaborates on future possibilities and ways to enable more efficient, scalable, and environmentally friendly MP cleanup. Overall, this review bridges the gap between contemporary MP remediation using adsorption techniques and adsorbent development.


Asunto(s)
Contaminantes Ambientales , Nanotubos de Carbono , Contaminantes Químicos del Agua , Purificación del Agua , Agua , Contaminantes Químicos del Agua/análisis , Plásticos , Microplásticos , Adsorción , Óxidos , Purificación del Agua/métodos
16.
J Colloid Interface Sci ; 659: 374-384, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38181701

RESUMEN

Lignin-derived carbon materials are widely used as electrode materials for supercapacitors. However, the electrochemical performance of these materials is limited by the surface chemistry and pore structure characteristics. Herein, a novel and sustainable strategy was proposed to prepare heteroatom-doped lignin-derived carbon material (Fe-NLC) with well-developed pore size distributions and enhanced graphitization structure via a facile lignin-Fe coordination method followed by carbonization. During carbonization, Fe3+ in lignin-metal complexes evolve into nanoparticles, which act as templates to introduce porous structures in carbon materials. Also, the lignin-Fe coordination structure endows the material with a higher graphitization during carbonization, thereby improving the structural properties of the carbon materials. Due to the removal of Fe3O4 template, the obtained Fe-NLC possessed reasonable pore distribution and nitrigen/oxygen (N/O) functional groups, which can improve the wettability of materials and introduce pseudocapacitance. Accordingly, Fe-NLC possesses a notable specific capacitance of 264 F/g at 0.5 A/g. Furthermore, a symmetric supercapacitor Fe-NLC//Fe-NLC with a high voltage window (1.8 V) was constructed. The symmetric supercapacitor exhibits a maximum energy density of 15.97 Wh/kg at 450 W/kg, demonstrating well application prospects. This paper proposes a novel approach for preparing carbon materials via lignin-metal coordination to provide an alternative way to explore sustainable and low-cost energy storage materials.

17.
Adv Colloid Interface Sci ; 329: 103176, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38761603

RESUMEN

Single-atom catalysts (SACs) with active metals dispersed atomically have shown great potential in heterogeneous catalysis due to the high atomic utilization and superior selectivity/stability. Synthesis of SACs using carbon-neutral biomass and its components as the feedstocks provides a promising strategy to realize the sustainable and cost-effective SACs preparation as well as the valorization of underused biomass resources. Herein, we begin by describing the general background and status quo of carbon-based SACs derived from biomass. A detailed enumeration of the common biomass feedstocks (e.g., lignin, cellulose, chitosan, etc.) for the SACs preparation is then offered. The interactions between metal atoms and biomass-derived carbon carriers are summarized to give general rules on how to stabilize the atomic metal centers and rationalize porous carbon structures. Furthermore, the widespread adoption of catalysts in diverse domains (e.g., chemocatalysis, electrocatalysis and photocatalysis, etc.) is comprehensively introduced. The structure-property relationships and the underlying catalytic mechanisms are also addressed, including the influences of metal sites on the activity and stability, and the impact of the unique structure of single-atom centers modulated by metal/biomass feedstocks interactions on catalytic activity and selectivity. Finally, we end this review with a look into the remaining challenges and future perspectives of biomass-based SACs. We expect to shed some light on the forthcoming research of carbon-based SACs derived from biomass, manifestly stimulating the development in this emerging research area.


Asunto(s)
Biomasa , Carbono , Catálisis , Carbono/química , Metales/química
18.
Int J Biol Macromol ; 258(Pt 2): 129132, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38171433

RESUMEN

Adhesives are used extensively in the wood industry. As resource and environmental issues become increasingly severe, the development of green and sustainable biomass-based adhesives has attracted increasing attention. In this work, a green wood adhesive is developed from poly(vinyl alcohol) and lignin with molecular designs of lignin extending beyond those in nature. The lignin undergoes extraction from corncob residue, aldehydration, and phenolisation (phenol, resorcinol, and catechol) to significantly increase the phenolic hydroxyl groups (over 7.92 mmol/g), which has the effect of enhancing the hydrogen bonding force between the adhesive and the wood, thereby greatly improving adhesive performance. Compared with pure PVA, polyphenol lignin-containing PVA showed improved adhesion strength and hydrophobicity. PVA/resorcinol-lignin has the significantly improved wood lap shear strength (6.27 MPa, 77.6 % improvement) and hydrophobicity (almost 100 % increase in wet shear strength). This research not only provides a green and high-performance alternative raw material for wood adhesives but also broadens the path for large-scale application of biomass.


Asunto(s)
Lignina , Polifenoles , Polifenoles/análisis , Lignina/química , Alcohol Polivinílico , Adhesivos/química , Madera/química , Fenoles/química , Metanol , Cloruro de Polivinilo , Resorcinoles
19.
Carbohydr Polym ; 334: 122034, 2024 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-38553233

RESUMEN

Cryogels that are constructed with cellulose nanofibrils (CNF) are important as green materials for a wide range of applications. However, their utilization is limited by inherent hydrophilicity and insufficient mechanical properties. Herein, a processable CNF/nanochitin (NCh)-stabilized Pickering emulsion that contains polylactide (PLA) in the oil phase is developed to directly produce ternary composite cryogels via freeze-drying. The complexation of CNF with NCh promotes CNF adsorption at the surface of PLA droplets, resulting in formation of uniform Pickering PLA droplets. The CNF/NCh complex-stabilized PLA droplets are easy to be translated to the internal structure of the cryogels, exhibiting lightweight nature and possessing highly porous structure. The interconnected network and lamellar structure formed by the CNF/NCh complexes, associating with inclusion of PLA particles, improve the cryogel structure integrity upon post-processing and endow hydrophilic cryogel with water resistance. This study offers a straightforward and eco-friendly Pickering emulsion template on fabrication of the CNF-based composite cryogel with controllable microstructure and mechanical performance, broadening construction of nanocellulose-based composites.

20.
Chem Sci ; 15(11): 3920-3927, 2024 Mar 13.
Artículo en Inglés | MEDLINE | ID: mdl-38487249

RESUMEN

Stimuli-responsive aggregation-induced emission (AIE) materials are highly sensitive and rapidly responsive to external signals, making them ideal solid materials for anti-counterfeiting encryption. However, the limited conformational and packing variations resulting from regio-isomerization with a single substituent restricts the stimuli-responsive behavior of these materials. In this work, several AIE-active regio-structural isomers based on the salicylaldehyde Schiff base scaffold have been straightforwardly obtained through multiple substitutions with bromide and triphenylamine moieties. Solvent-effect experiments demonstrate their different orders of charge-transfer and excited-state intramolecular proton transfer upon photoexcitation, indicating the regulation of excited-state processes via multi-site isomerization. These isomers also demonstrate mechanochromism and acidichromism, allowing for adjustable stimuli-responsive effects. As a demonstration, p-Br-TPA with both mechanochromism and acidichromism can be synergistically utilized for multi-level decryption. This study successfully regulates the evolution of excited states through multi-site isomerization, offering a general approach for achieving tunable stimuli-responsive properties in AIE-active salicylaldehyde Schiff bases toward multi-level decryption.

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