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1.
Small ; 20(10): e2305502, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37880909

RESUMO

Biomass-based hydrogels have attracted great attention in flexible and sustainable self-powered power sources but struggled to fabricate in a green, high-efficiency, and low-cost manner. Herein, a novel and facile alkali-polyphenol synergetic self-catalysis system is originally employed for the fast gelation of self-healable and self-adhesive lignin-based conductive hydrogels, which can be regarded as hydrogel electrodes of flexible triboelectric nanogenerators (TENGs). This synergy self-catalytic system comprises aqueous alkali and polyphenol-containing lignin, in which alkali-activated ammonium persulfate (APS) significantly accelerates the generation of radicals and initiates the polymerization of monomers, while polyphenol acts as a stabilizer to avoid bursting polymerization from inherent radical scavenging ability. Furthermore, multiple hydrogen bonds between lignin biopolymers and polyacrylamide (PAM) chains impart lignin-based hydrogels with exceptional adhesiveness and self-healing properties. Intriguingly, the alkaline conditions not only contribute to the solubility of lignin but also impart superior ionic conductivity of lignin-based hydrogel that is applicable to flexible TENG in self-powered energy-saving stair light strips, which holds great promise for industrial applications of soft electronics.

2.
Int J Mol Sci ; 24(12)2023 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-37373449

RESUMO

The structure of cellulolytic enzyme lignin (CEL) prepared from three bamboo species (Neosinocalamus affinis, Bambusa lapidea, and Dendrocalamus brandisii) has been characterized by different analytical methods. The chemical composition analysis revealed a higher lignin content, up to 32.6% of B. lapidea as compared to that of N. affinis (20.7%) and D. brandisii (23.8%). The results indicated that bamboo lignin was a p-hydroxyphenyl-guaiacyl-syringyl (H-G-S) lignin associated with p-coumarates and ferulates. Advanced NMR analyses displayed that the isolated CELs were extensively acylated at the γ-carbon of the lignin side chain (with either acetate and/or p-coumarate groups). Moreover, a predominance of S over G lignin moieties was found in CELs of N. affinis and B. lapidea, with the lowest S/G ratio observed in D. brandisii lignin. Catalytic hydrogenolysis of lignin demonstrated that 4-propyl-substituted syringol/guaiacol and propanol guaiacol/syringol derived from ß-O-4' moieties, and methyl coumarate/ferulate derived from hydroxycinnamic units were identified as the six major monomeric products. We anticipate that the insights of this work could shed light on the sufficient understanding of lignin, which could open a new avenue to facilitate the efficient utilization of bamboo.


Assuntos
Bambusa , Lignina , Lignina/química , Pirogalol , Bambusa/química , Catálise
3.
Molecules ; 28(19)2023 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-37836748

RESUMO

The application of lithium metal batteries is limited by the drawbacks of safety problems and Li dendrite formation. Quasi-solid-state electrolytes (QSSEs) are the most promising alternatives to commercial liquid electrolytes due to their high safety and great compatibility with electrodes. However, Li dendrite formation and the slow Li+ diffusion in QSSEs severely hinder uniform Li deposition, thus leading to Li dendrite growth and short circuits. Herein, an eco-friendly and low-cost sodium lignosulfonate (LSS)-assisted PVDF-based QSSE is proposed to induce uniform Li deposition and inhibit Li dendrite growth. Li symmetric cells with 5%-LSS QSSE possess a high Li+ transfer number of 0.79, and they exhibit a long cycle life of 1000 h at a current density/areal capacity of 1 mA cm-2/5 mAh cm-2. Moreover, due to the fast electrochemical dynamics endowed by the improved compatibility of the electrodes and fast Li+ diffusion, the LFP/5%-LSS/Li full cells still maintain a high capacity of 110 mAh g-1 after 250 cycles at 6C. This work provides a novel and promising choice that uses eco-friendly LSS as an additive to PVDF-based QSSE in Li metal batteries.

4.
Angew Chem Int Ed Engl ; 59(27): 10732-10745, 2020 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-31746521

RESUMO

Lithium-sulfur (Li-S) batteries are highly regarded as the next-generation energy-storage devices because of their ultrahigh theoretical energy density of 2600 Wh kg-1 . Sulfurized polyacrylonitrile (SPAN) is considered a promising sulfur cathode to substitute carbon/sulfur (C/S) composites to afford higher Coulombic efficiency, improved cycling stability, and potential high-energy-density Li-SPAN batteries. However, the instability of the Li-metal anode threatens the performances of Li-SPAN batteries bringing limited lifespan and safety hazards. Li-metal can react with most kinds of electrolyte to generate a protective solid electrolyte interphase (SEI), electrolyte regulation is a widely accepted strategy to protect Li-metal anodes in rechargeable batteries. Herein, the basic principles and current challenges of Li-SPAN batteries are addressed. Recent advances on electrolyte regulation towards stable Li-metal anodes in Li-SPAN batteries are summarized to suggest design strategies of solvents, lithium salts, additives, and gel electrolyte. Finally, prospects for future electrolyte design and Li anode protection in Li-SPAN batteries are discussed.

5.
Planta ; 247(5): 1077-1087, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29350280

RESUMO

MAIN CONCLUSION: Six types of lignin-carbohydrate complex (LCC) fractions were isolated from Eucalyptus. The acidic dioxane treatment applied significantly improved the yield of LCCs. The extraction conditions had a limited impact on the LCC structures and linkages. Characterization of the lignin-carbohydrate complex (LCC) structures and linkages promises to offer insight on plant cell wall chemistry. In this case, Eucalyptus LCCs were extracted by aqueous dioxane, and then precipitated sequentially by 70% ethanol, 100% ethanol, and acidic water (pH = 2). The composition and structure of the six LCC fractions obtained by selective precipitation were investigated by sugar analysis, molecular weight determination, and 2D HSQC NMR. It was found that the acidic (0.05-M HCl) dioxane treatment significantly improved the yield of LCCs (66.4% based on Klason lignin), which was higher than the neutral aqueous dioxane extraction, and the extraction condition showed limited impact on the LCC structures and linkages. In the fractionation process, the low-molecular-weight LCCs containing a high content of carbohydrates (60.3-63.2%) were first precipitated by 70% ethanol from the extractable solution. The phenyl glycoside (PhGlc) bonds (13.0-17.0 per 100Ar) and highly acetylated xylans were observed in the fractions recovered by the precipitation with 100% ethanol. On the other hand, such xylan-rich LCCs exhibited the highest frequency of ß-O-4 linkages. The benzyl ether (BE) bonds were only detected in the fractions obtained by acidic water precipitation.


Assuntos
Carboidratos/isolamento & purificação , Eucalyptus/metabolismo , Lignina/isolamento & purificação , Metabolismo dos Carboidratos , Carboidratos/química , Precipitação Química , Dioxanos/uso terapêutico , Lignina/química , Lignina/metabolismo , Espectroscopia de Ressonância Magnética , Peso Molecular
6.
Int J Mol Sci ; 19(1)2017 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-29267210

RESUMO

The lignin-carbohydrate complex (LCC) was isolated from milled wood lignin of 2- and 24-month-old crude bamboo (Neosinocalamus affinis) culms using acetic acid (AcOH) and then characterized. The results have shown that the LCC preparation from 2-month-old bamboo (L2) exhibited a slightly lower molecular weight than the LCC preparation from the 24-month-old bamboo (L24). Further studies using Fourier transform infrared spectroscopy (FT-IR) and heteronuclear single quantum coherence (2D-HSQC) NMR spectra analyses indicate that the LCC preparations included glucuronoarabinoxylan and G-S-H lignin-type with G>S>>H. The content of the S lignin units of LCC in the mature bamboo was always higher than in the young bamboo. Combined with sugar composition analysis, the contents of phenyl glycoside and ether linkages in the L24 preparation were higher than in the L2 preparation; however, there was a reverse relationship of ester LCC bonds in L2 and L24. Lignin-xylan was the main type of LCC linkage in bamboo LCCs. Lignin-lignin linkages in the LCC preparations included ß-ß, ß-5 and ß-1 carbon-to-carbon, as well as ß-O-4 ether linkages, but ß-1 linkages were not present in L2.


Assuntos
Bambusa/química , Carboidratos/química , Lignina/química , Substâncias Macromoleculares/química , Madeira/química , Ácido Acético/química , Configuração de Carboidratos , Estrutura Molecular , Peso Molecular , Xilanos/química
7.
Molecules ; 20(4): 6033-47, 2015 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-25853319

RESUMO

The amidine organocatalyst 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) is an effective nucleophilic catalyst. Biocomposites with tuneable properties were successfully synthesized by ring-opening graft polymerization (ROGP) of propylene carbonate (PC) onto xylan using DBU as a catalyst in the ionic liquid (IL) 1-allyl-3-methylimidazolium chloride ([Amim]Cl). The effects of reaction temperature, reaction time and the molar ratio of PC to anhydroxylose units (AXU) in xylan were investigated. The physico-chemical properties of xylan-graft-poly(propylene carbonate) (xylan-g-PPC) copolymers were characterised by FT-IR, NMR, TGA/DTG, AFM and tensile analysis. The FT-IR and NMR results indicated the successful attachment of PPC onto xylan. TGA/DTG suggested the increased thermal stability of xylan after the attachment of PPC side chains. AFM analysis revealed details about the molecular aggregation of xylan-g-PPC films. The results also showed that with the increased DS of xylan-g-PPC copolymers, the tensile strength and Young's modulus of the films decreased, while the elongation at break increased.


Assuntos
Líquidos Iônicos , Polimerização , Propano/análogos & derivados , Xilanos/química , Microscopia de Força Atômica , Ressonância Magnética Nuclear Biomolecular , Polímeros/química , Propano/química , Espectroscopia de Infravermelho com Transformada de Fourier , Termodinâmica
8.
BMC Plant Biol ; 14: 62, 2014 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-24618103

RESUMO

BACKGROUND: Polyphenol oxidase (PPO), often encoded by a multi-gene family, causes oxidative browning, a significant problem in many food products. Low-browning potatoes were produced previously through suppression of PPO gene expression, but the contribution of individual PPO gene isoform to the oxidative browning process was unknown. Here we investigated the contributions of different PPO genes to total PPO protein activity, and the correlations between PPO protein level, PPO activity and tuber tissue browning potential by suppression of all previously characterized potato PPO genes, both individually and in combination using artificial microRNAs (amiRNAs) technology. RESULTS: Survey of the potato genome database revealed 9 PPO-like gene models, named StuPPO1 to StuPPO9 in this report. StuPPO1, StuPPO2, StuPPO3 and StuPPO4 are allelic to the characterized POTP1/P2, POT32, POT33 and POT72, respectively. Fewer ESTs were found to support the transcriptions of StuPPO5 to StuPPO8. StuPPO9 related ESTs were expressed at significant higher levels in pathogen-infected potato tissues. A series of browning phenotypes were obtained by suppressing StuPPO1 to StuPPO4 genes alone and in combination. Down-regulation of one or several of the PPO genes did not usually cause up-regulation of the other PPO genes in the transgenic potato tubers, but resulted in reduced PPO protein levels. The different PPO genes did not contribute equally to the total PPO protein content in the tuber tissues, with StuPPO2 accounting for ~ 55% as the major contributor, followed by StuPPO1, ~ 25-30% and StuPPO3 and StuPPO4 together with less than 15%. Strongly positive correlations between PPO protein level, PPO activity and browning potential were demonstrated in our analysis. Low PPO activity and low-browning potatoes were produced by simultaneous down-regulation of StuPPO2 to StuPPO4, but the greatest reduction occurred when StuPPO1 to StuPPO4 were all suppressed. CONCLUSION: StuPPO1 to StuPPO4 genes contributed to browning reactions in tuber tissues but their effect was not equal. Different PPO genes may be regulated independently reflecting their diversified functions. Our results show that amiRNAs can be used to suppress closely related members of highly conserved multi-gene family. This approach also suggests a new strategy for breeding low-browning crops using small DNA inserts.


Assuntos
Catecol Oxidase/metabolismo , MicroRNAs/genética , Proteínas de Plantas/metabolismo , Solanum tuberosum/enzimologia , Catecol Oxidase/genética , Proteínas de Plantas/genética , Solanum tuberosum/genética
9.
Bioresour Technol ; 395: 130347, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38242243

RESUMO

The heavy metals, pesticides and dyes in agriculture and industry caused serious water pollution have increased the urgency for the advancement of biomass-based adsorbents due to their merits of low cost, high efficiency, and environmental sustainability. Thus, this review systematically examines the recent progress of lignin-based adsorbents dedicated to wastewater purification. Commencing with a succinct exposition on the intricate structure and prevalent forms of lignin, the review proceeds to expound rational design strategies tailored for lignin-based adsorbents coupled with adsorption mechanisms and regeneration methods. Emphasis is placed on the potential industrial applications of lignin-based adsorbents, accentuating their capacity for recovery and direct utilization post-use. The future challenges and outlooks associated with lignin-based adsorbents are discussed to provide novel perspectives for the development of high-performance and sustainable biosorbents, facilitating the effective removal of pollutants and the value-added utilization of resources in a sustainable manner.


Assuntos
Poluentes Ambientais , Poluentes Químicos da Água , Purificação da Água , Lignina , Corantes , Purificação da Água/métodos , Adsorção
10.
Int J Biol Macromol ; 273(Pt 1): 132993, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38862049

RESUMO

Low ionic conductivity and poor interface stability of poly(ethylene oxide) (PEO) restrict the practical application as polymeric electrolyte films to prepare solid-state lithium (Li) metal batteries. In this work, biomass-based carboxymethyl chitosan (CMCS) is designed and developed as organic fillers into PEO matrix to form composite electrolytes (PEO@CMCS). Carboxymethyl groups of CMCS fillers can promote the decomposition of Lithium bis(trifluoromethane sulfonimide) (LiTFSI) to generate more lithium fluoride (LiF) at CMCS/PEO interface, which not only forms ionic conductive network to promote the rapid transfer of Li+ but also effectively enhances the interface stability between polymeric electrolyte and Li metal. The enrichment of carboxyl, hydroxyl, and amidogen functional groups within CMCS fillers can form hydrogen bonds with ethylene oxide (EO) chains to improve the tensile properties of PEO-based electrolyte. In addition, the high hardness of CMCS additives can also strengthen mechanical properties of PEO-based electrolyte to resist penetration of Li dendrites. LiLi symmetric batteries can achieve stable cycle for 2500 h and lithium iron phosphate full batteries can maintain 135.5 mAh g-1 after 400 cycles. This work provides a strategy for the enhancement of ion conductivity and interface stability of PEO-based electrolyte, as well as realizes the resource utilization of biomass-based CMCS.


Assuntos
Quitosana , Condutividade Elétrica , Fontes de Energia Elétrica , Eletrólitos , Lítio , Polietilenoglicóis , Quitosana/química , Quitosana/análogos & derivados , Polietilenoglicóis/química , Lítio/química , Eletrólitos/química , Íons/química
11.
Int J Biol Macromol ; 269(Pt 2): 132145, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38723819

RESUMO

Sulfonated lignin-based dye dispersants have intensively attracted attention due to their low cost, renewability and abundant sources. However, their utilization is limited by the low content of sulfonic groups and high content of hydroxyl groups in their complex lignin structure, which results in various problems such as high reducing rate of dye, severe staining of the fibers and uneven dyeing. Here, the multi-site sulfonated lignin-based dispersants were prepared with high sulfonic group content (2.20 mmol/g) and low hydroxyl content (2.43 mmol/g). When using it as the dispersant, the dye uptake rate was improved from 69.23 % to 98.55 %, the reducing rate was decreased from 20.82 % to 2.03 %, the K/S value was reduced from 0.69 to 0.02, and the particle sizes in dye system before and after high temperature treatment were stabilized below 0.5 µm. Besides, the dispersion effect was significantly improved because no obvious separation between dye and water was observed even if without the assistance of grinding process. In short, the multi-site sulfonation method proposed in this work could remarkably improve the performances of the lignin-based dye dispersants, which would facilitate the development of the dye dispersion and the high value utilization of lignin.


Assuntos
Corantes , Lignina , Lignina/química , Corantes/química , Ácidos Sulfônicos/química , Tamanho da Partícula , Temperatura
12.
J Colloid Interface Sci ; 662: 138-148, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38340513

RESUMO

The shuttle effect, sluggish conversion kinetics, and uncontrollable lithium dendrites seriously hinder the practical application of lithium-sulfur (Li-S) batteries. Among many modified materials, covalent organic frameworks (COFs) stand out for their excellent ability to inhibit the shuttle effect, while their role in promoting lithium nucleation and catalyzing the conversion of sulfur species has been largely ignored. In this study, an integrated COF separator (TpPa@2400) is developed as a rapid lithium nucleator and sulfur species catalyst in fast-charging Li-S batteries. According to the adsorption energy and Bader charge results, Li atoms preferentially adsorb onto the surface of the TpPa@2400 separator, and the larger Bader charge value (0.52 |e|) of the TpPa@2400 separator also signifies faster lithium transport, promoting the nucleation of Li ions. Furthermore, density functional theory (DFT) theoretically demonstrates that the TpPa@2400 separator exhibits lower free energy for sulfur species interconversion. As a result, the TpPa@2400 separator enables the Li-Li symmetric cell with an extended cycle life of 6000 h at a current density/capacity of 10 mA cm-2/10 mAh cm-2. The Li-S battery assembled using the TpPa@2400 separator delivers a high capacity of 1636.4 mAh/g at 0.1C and a rapid sulfur species conversion capacity of 513.8 mAh/g at 2C.

13.
Biotechnol Bioeng ; 110(3): 729-36, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23042556

RESUMO

Although the effects of cellulose crystallinity and lignin content as two major structural features on enzymatic hydrolysis have been extensively studied, debates regarding their effects still exist. In this study, reconstitution of cellulose and lignin after 1-ethyl-3-methylimidazolium acetate ([C(2)mim][OAc]) pretreatment was proposed as a new method to study their effects on enzymatic digestibility. Different mechanisms of lignin content for reduction of cellulose hydrolysis were found between the proposed method and the traditional method (mixing of cellulose and lignin). The results indicated that a slight change of the crystallinity of the reconstituted materials may play a minor role in the change of enzyme efficiency. In addition, the present study suggested that the lignin content does not significantly affect the digestibility of cellulose, whereas the conversion of cellulose fibers from the cellulose I to the cellulose II crystal phase plays an important role when an ionic liquid pretreatment of biomass was conducted.


Assuntos
Celulases/antagonistas & inibidores , Celulases/metabolismo , Celulose/metabolismo , Inibidores Enzimáticos/metabolismo , Imidazóis/química , Líquidos Iônicos/química , Lignina/metabolismo , Hidrólise
14.
Nanotechnology ; 24(23): 235601, 2013 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-23676794

RESUMO

A facile and green method to synthesize stable Ag nanoparticles (Ag NPs) with a narrow size distribution in water is reported. Water-soluble quaternized carboxymethyl chitosan (QCMC) with a surfactant-like structure was used as both a reducing and stabilizing agent under microwave irradiation via the modified Tollens reaction. In order to study the preparation mechanism, carboxymethyl chitosan (CMC) and quaternized chitosan (QCS) were compared as both reducing and stabilizing agents. Full characterization was performed using UV-vis, XRD, TEM, AAS, FT-IR, NMR and TGA. The results revealed that the prepared Ag NPs were mostly spherical with a small proportion being cylinders or cuboids; they were stable due to the package of the macromolecules; the diameters were 10.24 ± 3.13 nm. The Tollens reaction followed first order kinetics, and the Ea was 102.4 kJ mol(-1) for QCMC/Ag NP composite. During the growth of the Ag NPs, some quaternary ammonium groups and carboxymethyl groups were respectively oxidized to -CH2COCH3 and -CH3 groups, and the quaternary ammonium groups were more helpful for the growth of Ag NPs than the carboxymethyl groups. In addition, QCMC/Ag NP composite had much higher thermal stability than QCMC.


Assuntos
Quitosana/análogos & derivados , Química Verde/métodos , Nanopartículas Metálicas/química , Prata/química , Quitosana/síntese química , Quitosana/química , Coloides , Cinética , Espectroscopia de Ressonância Magnética , Nanopartículas Metálicas/ultraestrutura , Tamanho da Partícula , Soluções , Espectrofotometria Ultravioleta , Espectroscopia de Infravermelho com Transformada de Fourier , Termogravimetria , Difração de Raios X
15.
Int J Mol Sci ; 14(11): 21394-413, 2013 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-24169436

RESUMO

In order to make better use of lignocellulosic biomass for the production of renewable fuels and chemicals, it is necessary to disrupt its recalcitrant structure through pretreatment. Specifically, organosolv pretreatment is a feasible method. The main advantage of this method compared to other lignocellulosic pretreatment technologies is the extraction of high-quality lignin for the production of value-added products. In this study, bamboo was treated in a batch reactor with 70% ethanol at 180 °C for 2 h. Lignin fractions were isolated from the hydrolysate by centrifugation and then precipitated as ethanol organosolv lignin. Two types of milled wood lignins (MWLs) were isolated from the raw bamboo and the organosolv pretreated residue separately. After the pretreatment, a decrease of lignin (preferentially guaiacyl unit), hemicelluloses and less ordered cellulose was detected in the bamboo material. It was confirmed that the bamboo MWL is of HGS type (p-hydroxyphenyl (H), vanillin (G), syringaldehyde (S)) associated with a considerable amount of p-coumarate and ferulic esters of lignin. The ethanol organosolv treatment was shown to remove significant amounts of lignin and hemicelluloses without strongly affecting lignin primary structure and its lignin functional groups.


Assuntos
Etanol/química , Lignina/química , Biomassa , Etanol/farmacologia , Glicosídeo Hidrolases/química , Lignina/isolamento & purificação , Ressonância Magnética Nuclear Biomolecular , Sasa/efeitos dos fármacos
16.
Int J Biol Macromol ; 247: 125809, 2023 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-37453645

RESUMO

The use of lignin carbon as an adsorbent for the adsorption of phosphates from wastewater is a promising technology. However, most lignin carbon-based adsorbents still suffer from low adsorption efficiency and poor selectivity. Herein, a novel FeLaO3-modified sulfomethylated lignin (SL) biochar adsorbent (FLO@CSL) was prepared for phosphate removal. The development of this adsorbent took into consideration the strong affinity of lanthanum (La) and iron (Fe) (hydro) oxides for phosphate and the excellent carrier properties of lignin-based biochar. As the core of FLO@CSL, FeLaO3 active sites are highly dispersed on the surface of SL biochar. Besides, doping of Fe(III) not only imparts magnetic properties to FLO@CSL, thereby effectively improving the separation efficiency of the adsorbent, but also enhances the phosphate adsorption performance. Performance studies revealed that FLO@CSL exhibits remarkable adsorption selectivity and substantial phosphate-adsorption capacity. Notably, the maximum adsorption capacity was found to be 137.14 mg P g-1. Phosphate adsorption on the FLO@CSL surfaces proceeds via chemisorption in a single layer, and ligand exchange plays an important role in determining the adsorption behaviour. Because of its exceptional selectivity, remarkable adsorption capacity and outstanding magnetic separation efficiency, FLO@CSL is a highly promising adsorbent material for effectively treating phosphates in wastewater.


Assuntos
Fosfatos , Poluentes Químicos da Água , Lantânio , Lignina , Ferro , Águas Residuárias , Cinética , Água , Carvão Vegetal , Adsorção , Poluentes Químicos da Água/análise , Fenômenos Magnéticos
17.
J Hazard Mater ; 448: 130988, 2023 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-36860059

RESUMO

Developing the lignin-based functional materials for uranium uptake is extremely attractive, but challenging due to the complex structure, poor solubility and reactivity of lignin. Herein, a novel phosphorylated lignin (LP)/sodium alginate/ carboxylated carbon nanotube (CCNT) composite aerogel (LP@AC) with vertically oriented lamellar configuration was created for efficient uranium uptake from acidic wastewater. The successful phosphorylation of lignin by a facile solvent-free mechanochemical method achieved more than six-times enhancement in U(VI) uptake capacity of lignin. While, the incorporation of CCNT not only increased the specific surface area of LP@AC, but also improved its mechanical strength as a reinforcing phase. More importantly, the synergies between LP and CCNT components endowed LP@AC with an excellent photothermal performance, resulting in a local heat environment on LP@AC and further boosting the U(VI) uptake. Consequently, the light irradiated LP@AC exhibited an ultrahigh U(VI) uptake capacity (1308.87 mg g-1), 61.26% higher than that under dark condition, excellent adsorptive selectivity and reusability. After exposure to 10 L of simulated wastewater, above 98.21% of U(VI) ions could be rapidly captured by LP@AC under light irradiation, revealing the tremendous feasibility in industrial application. The electrostatic attraction and coordination interaction were considered as the main mechanism for U(VI) uptake.

18.
iScience ; 26(8): 107416, 2023 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-37564699

RESUMO

Simultaneous photocatalytic biorefinery and CO2 reduction to co-produce fuels and high value-added chemicals have recently attracted significant attention; however, comprehensive studies are still lacking. Herein, we report the preparation of highly crystalline oxygen-doped carbon nitride nanotubes (O-CNNTs-x) using an ammonium fluoride-assisted hydrothermal/calcination strategy. The hollow structure, high crystallinity, and O incorporation endowed the O-CNNTs-x with photocatalytic activity by considerably improving optical absorption and modulating the charge carrier motion. The lactic acid yield and CO evolution rate over O-CNNTs-2.0 reached 82.08% and 67.95 µmol g-1 h-1, which are 1.57- and 7.37-fold times higher than those of CN, respectively. Moreover, ·OH plays a key role in the oxidation half-reaction. This study offers a facile approach for fabricating highly crystalline element-doped CN with a customizable morphology and electronic properties and demonstrates the viability of co-photocatalytic CO2 reduction and biomass selective oxidation.

19.
Carbohydr Polym ; 300: 120244, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36372506

RESUMO

A novel multi-layered reticular polyamidoxime (PAO)-functionalized holocellulose bundles (ML-r-PAO@HB) with abundant oriented micro-channels and high mechanical strength was created via a facile solvent-exchange strategy and used for the first time to capture uranium from seawater. Due to the hydrophobic interaction of PAO chains induced by the solvent-exchange, multi-layered reticular PAO was successfully self-assembled onto the oriented micro-channels of the HB, which greatly improved the accessibility to the adsorption sites by increasing the exposed surface of PAO. The ML-r-PAO@HB exhibited high uptake capacity (851.42 mg g-1 PAO) and excellent adsorptive selectivity for U(VI) ions. After exposure to 500-L natural seawater for 28 days, an ultra-high uranium extraction capacity (9.74 mg g-1 PAO) was achieved by ML-r-PAO@HB. The N and O atoms in the -C(NH2)N-OH group were the main coordination sites for U(VI) uptake. These wonderful performances render the ML-r-PAO@HB highly desirable for the large-scale uranium extraction from seawater.


Assuntos
Urânio , Urânio/química , Água do Mar/química , Adsorção , Solventes
20.
iScience ; 26(3): 106187, 2023 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-36879809

RESUMO

Epoxy resin is widely used in various fields of the national economy due to its excellent chemical and mechanical properties. Lignin is mainly derived from lignocelluloses as one of the most abundant renewable bioresources. Due to the diversity of lignin sources and the complexity as well as heterogeneity of its structure, the value of lignin has not been fully realized. Herein, we report the utilization of industrial alkali lignin for the preparation of low-carbon and environmentally friendly bio-based epoxy thermosetting materials. Specifically, epoxidized lignin with substituted petroleum-based chemical bisphenol A diglycidyl ether (BADGE) in various proportions was cross-linked to fabricate thermosetting epoxies. The cured thermosetting resin revealed enhanced tensile strength (4.6 MPa) and elongation (315.5%) in comparison with the common BADGE polymers. Overall, this work provides a practicable approach for lignin valorization toward tailored sustainable bioplastics in the context of a circular bioeconomy.

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