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1.
Nanotechnology ; 35(9)2023 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-38016442

RESUMO

Lithium-sulfur (Li-S) batteries have gained considerable attention for high theoretical specific capacity and energy density. However, their development is hampered by the poor electrical conductivity of sulfur and the shuttle of polysulfides. Herein, the acidified bamboo-structure carbon nanotubes (BCNTs) were mixed with polyvinylidene difluoride and pyrolyzed at high-temperature to obtain the fluorinated bamboo-structure carbon nanotubes (FBCNTs), which were compounded with sulfur as the cathode. The prepared S@FBCNTs with sulfur loading reaching 74.2 wt.% shows a high initial specific capacity of 1407.5 mAh·g-1at the discharge rate of 0.1 C. When the discharge rate was increased to 5 C, the capacity could be maintained at 622.3 mAh·g-1. The electrical conductivity of carbon nanotubes is effectively improved by semi-ionic C-F bonds formed by the doped F atoms and carbon atoms. Simultaneously, the surface of the F-containing carbon tubes exhibits strong polarity and strong chemisorption effect on polysulfides, which inhibits the shuttle effect of Li-S batteries.

2.
Molecules ; 28(16)2023 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-37630369

RESUMO

This work explores a simple way to regulate the morphology and structure of biomass-based carbon and effectively utilize its internal functional groups as the substrate for the next energy materials. The unique randomly oriented and highly interconnected cordyceps-like 3D structure of rice husk is formed by direct high-temperature carbonization, and the main component is SiC. The well-arranged cordyceps-like structure of SiC demonstrates a remarkable structural/chemical stability and a high rate of electron migration, and further could be used as a stable substrate for metal deposition and find application in the field of electrocatalysis. The oxygen evolution reaction catalyst (SiC-C@Fe3O4) prepared by chemical deposition exhibits a low overpotential (260 mV), low Tafel slope (56.93 mV dec-1), high electrochemical active surface area (54.92 mF cm-2), and low Rct value (0.15 Ω) at a current density of 10 mA cm-2 in 1 M KOH electrolyte. The produced natural Si-C composite materials overcome the limitations imposed by the intricate internal structure of silicon-rich biomass. The existence of this stable substrate offers a novel avenue for maximizing the utilization of rice-husk-based carbon, and broadens its application field. At the same time, it also provides a theoretical basis for the use of rice husks in the field of hydrogen production by electrolysis of water, thus promoting their high-value utilization.

3.
Molecules ; 27(4)2022 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-35209240

RESUMO

Superhydrophobic coatings have drawn much attention in recent years for their widespread potential applications. However, there are challenges to find a simple and cost-effective approach to prepare superhydrophobic materials and coatings using natural polymer. Herein, we prepared a kraft lignin-based superhydrophobic powder via modifying kraft lignin through 1H, 1H, 2H, 2H-perfluorodecyl-triethoxysilane (PFDTES) substitution reaction, and constructed superhydrophobic coatings by direct spraying the suspended PFDTES-Lignin powder on different substrates, including glass, wood, metal and paper. The prepared lignin-based coatings have excellent repellency to water, with a water contact angle of 164.7°, as well as good friction resistance, acid resistance, alkali resistance, salt resistance properties and quite good self-cleaning performance. After 30 cycles of sand friction or being stayed in 2 mol/L HCl, 0.25 mol/L NaOH and 2 mol/L NaCl solution for 30 min, the coatings still retain super hydrophobic capability, with contact angles higher than 150°. The superhydrophobic performance of PFDTES-Lignin coatings is mainly attributed to the constructed high surface roughness and the low surface energy afforded by modified lignin. This lignin-based polymer coating is low-cost, scalable, and has huge potential application in different fields, providing a simple way for the value-added utilization of kraft lignin.

4.
Inorg Chem ; 60(7): 5034-5041, 2021 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-33677968

RESUMO

Three photosensitive tert-butylcalix[n]arene (TBC[n], n = 4, 6, 8)-protected titanium-oxo clusters (TOCs), formulated as [Ti4(µ3-O)2(TBC[4])2(OiPr)4(DEF)2]·DEF (1, TBC[4]-Ti4, DEF = N,N-diethylformamide), [Ti4(µ4-O)TBC[6](OCH3)9]·H2O (2, TBC[6]-Ti4), and [Ti4(µ3-O)2(OiPr)4TBC[8](DEF)2]·DEF (3, TBC[8]-Ti4), were successfully synthesized and characterized. Because of the generation of charge transfer from TBC[n] to the TiO core, the three TBC[n]-decorated TOCs show a broadened visible-light absorption and narrowed optical band gap based on the UV-visible spectra and density functional theory calculations. The corresponding photosensitive electrodes prepared using these three TOCs exhibit stable photocurrent responses. Furthermore, their photocatalytic performances for hydrogen evolution and methylene blue degradation were evaluated, and all of the materials display excellent photocatalytic activity and stability. The calixarene-Ti coordination is therefore an effective strategy to enlarge the visible-light absorption band of Ti-O materials and improve their photoelectric/photocatalytic performances.

5.
Water Sci Technol ; 81(1): 52-61, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32293588

RESUMO

A fiber-network chitosan film with three-dimensional interconnected structure was prepared in an alkali/urea solution and regenerated from an ethanol/water coagulation solution. The surface morphology and structure were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), N2 adsorption-desorption, attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) and X-ray photoelectron spectroscopy (XPS). Batch adsorption for uranium U(VI) was conducted to investigate the effects of pH, contact time and initial uranium concentration on adsorption capacity. The adsorption of CS-80% was in good agreement with the pseudo-second-order kinetic model and Langmuir isotherm model. The three-dimensional interconnected structure provided more active sites and favored the diffusion of uranium solute, and therefore enhanced the adsorption capacity. The maximum adsorption capacity at pH 5 was 196.735 mg/g. The adsorption mechanism was attributed to chelation and coordination of uranium with -NH2 and -OH groups on chitosan molecules.


Assuntos
Quitosana , Urânio , Poluentes Químicos da Água , Adsorção , Concentração de Íons de Hidrogênio , Cinética , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X
6.
Anal Bioanal Chem ; 411(27): 7127-7136, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31468080

RESUMO

Fluorescence detection of H2S in living organisms is greatly advantageous because it is nondestructive and can be used for in situ analysis. We have constructed a novel rhodamine analogue dye (Rho630) by extending the conjugated system of rhodamine to create a novel cell-trappable H2S fluorescent probe Rho630-AM-H2S with red light emission. Its application for H2S fluorescence detection in living HeLa cells and zebrafish was investigated. As expected, Rho630-AM-H2S showed a huge fluorescence turn-on response of about 20-fold at 630 nm and good selectivity toward H2S in solution. An MTT assay demonstrated that the probe showed negligible cytotoxicity in the concentrations typically used in fluorescence imaging experiments. Cell imaging experiments revealed that compared with compound 4 without cell-trappable unit modification, Rho630-AM-H2S exhibited remarkably enhanced cell penetration ability, as an enormous fluorescence signal increase was observed at the red channel within 5 min after Rho630-AM-H2S was incubated with HeLa cells. Finally, the probe Rho630-AM-H2S was used to detect H2S in living HeLa cells and zebrafish with great fluorescence enhancement in the red channel. Graphical abstract.


Assuntos
Corantes Fluorescentes/química , Sulfeto de Hidrogênio/análise , Imagem Óptica/métodos , Rodaminas/química , Animais , Células HeLa , Humanos , Peixe-Zebra
7.
Bioorg Chem ; 91: 103162, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31382058

RESUMO

In this work, a series of novel moxifloxacin-amide-1,2,3-triazole-isatin hybrids 7a-l were designed and synthesized. The in vitro antibacterial activity against a panel of clinically important Gram-positive and Gram-negative bacteria including drug-resistant pathogens was also evaluated. All hybrids showed considerable activity against the tested pathogens with MIC values of ≤0.03 to 128 µg/mL, and some of them such as hybrids 7e, 7g and 7j were comparable to or better than the parent moxifloxacin (MIC: ≤0.03-8 µg/mL). Moreover, hybrids 7e, 7g and 7j also demonstrated low cytotoxicity towards CHO cells. However, the in vivo pharmacokinetic profiles of these three hybrids were generally far inferior to the parent moxifloxacin. The structure-activity relationship and structure-cytotoxicity relationship were also studied and discussed which may help with the identification of new chemical entities as potent antibacterial agents.


Assuntos
Antibacterianos/síntese química , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Infecções Bacterianas/tratamento farmacológico , Desenho de Fármacos , Isatina/química , Moxifloxacina/química , Triazóis/química , Infecções Bacterianas/patologia , Humanos , Simulação de Acoplamento Molecular , Estrutura Molecular , Relação Estrutura-Atividade
8.
Molecules ; 23(8)2018 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-30103485

RESUMO

The presence of dyes in wastewater effluents made from the textile industry is a major environmental problem due to their complex structure and poor biodegradability. In this study, a cationic lignin polymer was synthesized via the free radical polymerization of lignin with [2-(methacryloyloxy) ethyl] trimethyl ammonium chloride (METAC) and used to remove anionic azo-dyes (reactive black 5, RB5, and reactive orange 16, RO16) from simulated wastewater. The effects of pH, salt, and concentration of dyes, as well as the charge density and molecular weight of lignin-METAC polymer on dye removal were examined. Results demonstrated that lignin-METAC was an effective flocculant for the removal of dye via charge neutralization and bridging mechanisms. The dye removal efficiency of lignin-METAC polymer was independent of pH. The dosage of the lignin polymer required for reaching the maximum removal had a linear relationship with the dye concentration. The presence of inorganic salts including NaCl, NaNO3, and Na2SO4 had a marginal effect on the dye removal. Under the optimized conditions, greater than 98% of RB5 and 94% of RO16 were removed at lignin-METAC concentrations of 120 mg/L and 105 mg/L in the dye solutions, respectively.


Assuntos
Cátions , Lignina/química , Polímeros/química , Águas Residuárias/química , Compostos Azo/química , Floculação , Concentração de Íons de Hidrogênio , Peso Molecular , Poluentes Químicos da Água , Purificação da Água/métodos
9.
Int J Biol Macromol ; 256(Pt 1): 128424, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38008139

RESUMO

A large number of fresh fruits are wasted in the supply chain due to spoilage, so it is crucial to develop fruit preservation materials. Herein, two novel Ag-MOFs/carboxymethyl filter paper (Ag-MOFs/CMFP) composites were successfully synthesized by in situ facile synthesis, which can be used as packaging materials to delay fruit spoilage. The synthesis process is simple and environmentally friendly, and the reaction conditions are mild. The mechanical property, water stability, and antibacterial activity of the as-synthesized Ag-MOFs/CMFP composites were investigated. Specifically, the composites exhibited high mechanical performance and the tensile strength was >10.00 MPa. Moreover, the composites displayed good water stability and can remain stable in water environment for >7 days, which can be attributed to the strong interaction between Ag-MOFs and CMFP. Significantly, Ag-MOF particles endow the composite papers with excellent antibacterial activity, which can inactivate 99.9 % of the bacteria. Attributed to these characteristics, these composite papers were used as fruit fresh-keeping materials and can prolong the shelf-life of cherry tomatoes and peaches for >10 days. This research not only provides a facile synthesis strategy for the flexible MOFs paper, but also provides instructive guidance for related research on fruit preservation materials.


Assuntos
Celulose , Frutas , Prata/farmacologia , Antibacterianos/farmacologia , Água
10.
Int J Biol Macromol ; 257(Pt 2): 128760, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38103662

RESUMO

As a biomarker of oxidative stress, hydrogen peroxide (H2O2) plays a complex role in organisms, including regulating cell signaling, respiration, the immune system, and other life processes. Therefore, it is important to develop a tool that can simply and effectively monitor H2O2 levels in organisms and the environment. In this work, naphthalene fluorophores with a borate structure were introduced into chitosan (CTS) azide, and a CTS-based fluorescence sensor (CTS-HP) was designed for sensitive H2O2 detection. The biocompatibility and degradability of CTS endowed CTS-HP with reduced biotoxicity compared with organic fluorescent dyes, and the substitution degree of fluorophores on the CTS chains was 0.703. The randomly coiled chain structure of the CTS-HP probe enabled the boronic acid recognition sites on the fluorophores to achieve the enrichment of analyte H2O2 through a synergistic effect. Therefore, the probe CTS-HP (10 µg mL-1) exhibited a 21-fold fluorescence enhancement and good detection limit (LOD = 8.98 nM) in H2O2 solution, reaching the maximum fluorescence response faster (within 16 min). The probe also successfully achieved the fluorescence imaging of endogenous and exogenous H2O2 in zebrafish and living cells and labeled the recovery experiment of H2O2 in real water samples (recoveries rates of 90.93-102.9 % and RSD < 3.09 %).


Assuntos
Quitosana , Peróxido de Hidrogênio , Humanos , Animais , Peixe-Zebra , Células HeLa , Corantes Fluorescentes/química , Água
11.
Polymers (Basel) ; 16(2)2024 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-38257000

RESUMO

Industrial lignin, a by-product of pulping for papermaking fibers or of second-generation ethanol production, is primarily served as a low-grade combustible energy source. The fabrication of high-value-added functional materials with industrial lignin is still a challenge. Herein, a three-dimensional hierarchical lignin-derived porous carbon (HLPC) was prepared with lignosulfonate as the carbon source and MgCO3 as the template. The uniform mixing of precursor and template agent resulted in the construction of a three-dimensional hierarchical porous structure. HLPC presented excellent electromagnetic wave (EMW) absorption performance. With a low filler content of 7 wt%, HLPC showed a minimum reflection loss (RL) value of -41.8 dB (1.7 mm, 13.8 GHz), and a maximum effective absorption bandwidth (EAB) of 4.53 GHz (1.6 mm). In addition, the enhancement mechanism of HLPC for EMW absorption was also explored through comparing the morphology and electromagnetic parameters of lignin-derived carbon (LC) and lignin-derived porous carbon (LPC). The three-dimensional hierarchical porous structure endowed the carbon with a high pore volume, resulting in an abundant gas-solid interface between air and carbon for interfacial polarization. This structure also provided conductive networks for conduction loss. This work offers a strategy to synthesize biomass-based carbon for high-performance EMW absorption.

12.
Biosens Bioelectron ; 259: 116405, 2024 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-38776801

RESUMO

Alzheimer's disease (AD) is affecting more and more people worldwide without the effective treatment, while the existed pathological mechanism has been confirmed barely useful in the treatment. Amyloid-ß peptide (Aß), a main component of senile plaque, is regarded as the most promising target in AD treatment. Aß clearance from AD brain seems to be a reliably therapeutic strategy, as the two exited drugs, GV-971 and aducanumab, are both developed based on it. However, doubt still exists. To exhaustive expound on the pathological mechanism of Aß, rigorous analyses on the concentrations and aggregation forms are essential. Thus, it is attracting broad attention these years. However, most of the sensors have not been used in pathological studies, as the lack of the bridge between analytical chemist and pathologists. In this review, we made a brief introduce on Aß-related pathological mechanism included in ß-amyloid hypothesis to elucidate the detection conditions of sensor methods. Furthermore, a summary of the sensor methods was made, which were based on Aß concentrations and form detections that have been developed in the past 10 years. As the greatest number of the sensors were built on fluorescent spectroscopy, electrochemistry, and Roman spectroscopy, detailed elucidation on them was made. Notably, the aggregation process is another important factor in revealing the progress of AD and developing the treatment methods, so the sensors on monitoring Aß aggregation processes were also summarized.


Assuntos
Doença de Alzheimer , Peptídeos beta-Amiloides , Técnicas Biossensoriais , Peptídeos beta-Amiloides/análise , Peptídeos beta-Amiloides/metabolismo , Peptídeos beta-Amiloides/química , Humanos , Técnicas Biossensoriais/métodos , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Animais , Espectrometria de Fluorescência/métodos , Técnicas Eletroquímicas/métodos , Anticorpos Monoclonais Humanizados
13.
Dalton Trans ; 53(13): 6041-6049, 2024 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-38470841

RESUMO

Exploiting effective, stable, and cost-efficient electrocatalysts for the water oxidation reaction is highly desirable for renewable energy conversion techniques. Constructional design and compositional manipulation are widely used approaches to efficaciously boost the electrocatalytic performance. Herein, we designed a NiFe-bimetallic sulfide/N-doped carbon composite via a two-step thermal treatment of Prussian blue analogues/cellulose nanofibers (PBA/CNFs) film. The NiFe-bimetallic sulfide/N-doped carbon composite displayed enhanced OER performance in an alkaline environment, with an overpotential of 282 mV at 10 mA cm-2, a Tafel slope of 59.71 mV dec-1, and good stability, making the composite a candidate electrocatalyst for OER-related energy equipment. The introduction of CNFs in the precursor prevented the aggregation of PBA nanoparticles (NPs), exposed more active sites, and the resulting carbon substrate enhanced the electroconductivity of the composite. Moreover, the synergistic effect of Ni and Fe in the bimetallic sulfide could modulate the configuration of electrons, enrich the catalytically active sites, and augment the electric conductivity, thus ameliorating the OER performance. This study broadens the application of MOF-CNF composites to construct hierarchical structures of metal compounds and provides some thoughts for the development of cost-effective precious-metal-free catalysts for electrocatalysis.

14.
Talanta ; 273: 125894, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38461644

RESUMO

Hydrogen peroxide (H2O2) is a reactive oxygen species (ROS) that can be used as a marker for the occurrence of oxidative stress in the organism. Lysosomes serve as intracellular digestive sites, and when the concentration of H2O2 in them is abnormal, lysosomal function is often impaired, leading to the development of diseases. Hydrogen sulfide (H2S) acts as a gaseous signaling molecule that scavenges H2O2 from cells and tissues, thereby maintaining the redox environment of the body. However, most of the reported hydrogen peroxide fluorescent probes so far can only detect H2O2, but cannot maintain the intracellular redox environment. In this paper, an H2O2 fluorescent probe LN-HOD with lysosomal targeting properties was designed and synthesized by combining the H2O2 recognition site with a naphthylamine fluorophore via a thiocarbamate moiety. The probe has the advantages of large Stokes shift (110 nm), high sensitivity and good H2S release capability. The probe LN-HOD can be used to detect H2O2 in cells, zebrafish and plant roots. In addition, LN-HOD detects changes in the concentration of H2O2 in plant roots when Arabidopsis is stressed by cadmium ion (Cd2+). And through its ability to release H2S, it can help to remove excess H2O2 and maintain the redox environment in cells, zebrafish and plant roots. The present work provides new ideas for the detection and assisted removal of H2O2, which contributes to the in-depth study of the cellular microenvironment in organisms.


Assuntos
Corantes Fluorescentes , Sulfeto de Hidrogênio , Animais , Humanos , Corantes Fluorescentes/metabolismo , Peróxido de Hidrogênio/metabolismo , Peixe-Zebra , Sulfeto de Hidrogênio/metabolismo , Oxirredução , Lisossomos/metabolismo , Células HeLa
15.
Spectrochim Acta A Mol Biomol Spectrosc ; 314: 124180, 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38522378

RESUMO

N2H4 is a common raw material used in the production of pesticides and has good water solubility, so it may contaminate water sources and eventually enter living organisms, causing serious health problems. Viscosity is an important indicator of the cellular microenvironment and an early warning signal for many diseases. The high reactivity of hydrazine depletes glutathione (GSH) in hepatocytes, causing oxidative stress ultimately leading to significant changes in intracellular viscosity and even death. Therefore, it is particularly important to develop an effective method to detect N2H4 and viscosity in environmental and biological systems. On this basis, we developed two fluorescent probes, BDD and BHD, based on xanthene and 2-benzothiazole acetonitrile. The experimental results show that BHD and BDD have good imaging capabilities for N2H4 in cells, zebrafish and Arabidopsis. BHD and BDD also showed sensitive detection and fluorescence enhancement in the near-infrared region when the intracellular viscosity was changed. Notably, the probe BDD has also successfully imaged N2H4 in a variety of real water samples.


Assuntos
Corantes Fluorescentes , Peixe-Zebra , Animais , Humanos , Viscosidade , Xantenos , Água , Hidrazinas , Células HeLa , Espectrometria de Fluorescência
16.
Int J Biol Macromol ; 254(Pt 1): 127659, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37898243

RESUMO

Traditional paper-based packaging commonly needs to be coated to achieve sufficient mechanical and barrier performances. In this research, a bio-based coating for paper was developed from carbamate starch (Sc), calcium lignosulfonate (CL), and cellulose nanofibrils (CNF). Controlling the electrostatic and hydrogen-bonding interactions among the components of the coating was conducive to tailoring the structure and performance of the coated paper. When the degree of substitution (Ds) of Sc was 0.10, the amount of CL was 1.00 g, and the amount of CNF was 0.65 % of the weight of Sc, the paper coated with the resulting 0.10Sc-1.00CL-0.65CNF coating exhibited increased hydrophobicity and excellent mechanical, air-barrier, and UV-light-barrier properties. After the addition of 0.10 % of silver nano-particles (AgNPs) to the 0.10Sc-1.00CL-0.65CNF coating, the paper coated with the resulting 0.10Sc-1.00CL-0.65CNF-0.10AgNPs coating exhibited good antibacterial activity against Escherichia coli and Staphylococcus aureus. The coated paper was used as the packaging for cherry tomatoes stored under ambient conditions. Due to the synergistic preservation effects of the Sc-CL-CNF coating and AgNPs, the shelf life of the cherry tomatoes was at least 7 days. The coated paper described herein has the potential for applications in the food packaging sector.


Assuntos
Celulose , Nanopartículas Metálicas , Celulose/farmacologia , Celulose/química , Prata/farmacologia , Prata/química , Amido , Nanopartículas Metálicas/química , Embalagem de Alimentos/métodos , Carbamatos/farmacologia , Antibacterianos/farmacologia , Antibacterianos/química
17.
Int J Biol Macromol ; 273(Pt 2): 132640, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38825280

RESUMO

The high energy density and robust cycle properties of lithium-ion batteries contribute to their extensive range of applications. Polyolefin separators are often used for the purpose of storing electrolytes, hence ensuring the efficient internal ion transport. Nevertheless, the electrochemical performance of lithium-ion batteries is constrained by its limited interaction with electrolytes and poor capacity for cation transport. This work presents the preparation of a new bio-based nanofiber separator by combining oxidized lignin (OL) and halloysite nanotubes (HNTs) with polyimide (PI) using an electrospinning technique. Analysis was conducted to examine and compare the structure, morphology, thermal characteristics, and EIS of the separator with those of commercially available polypropylene separator (PP). The results indicate that the PI@OL and PI-OL@ 10 % HNTs separators exhibit higher lithium ion transference number and ionic conductivity. Moreover, the use of HNTs successfully impeded the proliferation of lithium dendrites, hence exerting a beneficial impact on both the cycle performance and multiplier performance of the battery. Consequently, after undergoing 300 iterations, the battery capacity of LiFePO4|PI-OL@ 10 % HNTs|Li stays at 92.1 %, surpassing that of PP (86.8 %) and PI@OL (89.6 %). These findings indicate that this new bio-based battery separator (PI-OL@HNTs) has the great potential to serve as a substitute for the commonly used PP separator in lithium metal batteries.


Assuntos
Argila , Fontes de Energia Elétrica , Lignina , Lítio , Nanofibras , Nanotubos , Lítio/química , Nanotubos/química , Nanofibras/química , Lignina/química , Argila/química , Oxirredução , Resinas Sintéticas/química
18.
Int J Biol Macromol ; 264(Pt 1): 130526, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38431008

RESUMO

Although a promising method for lignin depolymerization, photocatalysis faces the challenge of low efficiency. In this study, MoS2/ZnO heterojunction catalysts, endowed with piezocatalysis and photocatalytic capabilities, were crafted through Zn ion intercalation for the depolymerization of phenoxyphenylethanol (PP-ol) and alkali lignin. Then, the synergistic interplay between ultrasonic-induced piezoelectric fields and heterojunctions was analyzed. The amalgamation of the piezoelectric field and heterojunction in MoS2/ZnO catalysts resulted in a diminished photogenerated hole/electron recombination efficiency, thereby fostering the generation of ·OH during the reaction. This pivotal role of ·OH emerged as a crucial reactive substance, converting 95.8 % of PP-ol through ß-O-4 bond breaking within a 3-h treatment. By incorporating ultrasonic, the contact probability of PP-ol with the catalyst was significantly improved, resulting in efficient conversion even with a reduced amount of acetonitrile in the solvent system (20 %). Furthermore, ultrasonic-light methods show high efficiency for depolymerizing Alkali lignin (AL), with 33.2 % of lignin undergoing depolymerization in a 4-h treatment. This treatment simultaneously reduces the molecular weight of AL and cleaves numerous chemical bonds within it. Overall, this work presents a green approach to lignin depolymerization, providing insights into the synergistic action of ultrasonic and photocatalysis.


Assuntos
Lignina , Óxido de Zinco , Lignina/química , Ultrassom , Molibdênio , Catálise , Álcalis
19.
Int J Biol Macromol ; 250: 126157, 2023 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-37549768

RESUMO

Formaldehyde (HCHO) is a common environmental toxicant that can harm the human respiratory tract and nervous system when exposed for long period of time. As a carcinogen, HCHO also increases the risk of cancer in humans. HCHO can be produced endogenously in living systems and plays an essential role in physiological and biochemical reactions and pathogenesis. Therefore, monitoring the level of HCHO in vivo and in vitro has become the focus of attention. The designed naphthalene fluorophore was introduced onto modified chitosan to prepare a chitosan-based fluorescent probe (CS-FA) for HCHO detection. Compared to other small-molecule probe analogs for the detection of HCHO, the randomly coiled polymer chain of chitosan enabled CS-FA to "enrich" HCHO using the synergistic binding of hydrazino-naphthalimide recognition sites. Thus, the reaction of the analyte with the recognition site was accelerated, resulting in a faster equilibrium fluorescence response (2-3 min) and high sensitivity. In addition, the introduction of biomass material chitosan also improved the biocompatibility of the probe. Then a series of composite materials (test strips and hydrogel) were prepared based on the probe to expand the application form of the probe.

20.
J Inorg Biochem ; 245: 112252, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37207465

RESUMO

Copper-related reactive oxygen species (ROS) formation can lead to neuropathologic degradation associated with Alzheimer's disease (AD) according to amyloid cascade hypothesis. A complexing agent that can selectively chelate with copper ions and capture copper ions from the complex formed by copper ions and amyloid-ß (Cu - Aß complex) may be available in reducing ROS formation. Herein, we described applications of guluronic acid (GA), a natural oligosaccharide complexing agent obtained from enzymatic hydrolysis of brown algae, in reducing copper-related ROS formation. UV-vis absorption spectra demonstrated the coordination between GA and Cu(II). Ascorbic acid consumption and coumarin-3-carboxylic acid fluorescence assays confirmed the viability of GA in reducing ROS formation in solutions containing other metal ions and Aß. Fluorescence kinetics, DPPH radical clearance and high resolution X - ray photoelectron spectroscopy results revealed the reductivity of GA. Human liver hepatocellular carcinoma (HepG2) cell viability demonstrated the biocompatibility of GA at concentrations lower than 320 µM. Cytotoxic results of human neuroblastoma (SH-SY5Y) cells verified that GA can inhibit copper-related ROS damage in neuronal cells. Our findings, combined with the advantages of marine drugs, make GA a promising candidate in reducing copper-related ROS formation associated with AD therapy.


Assuntos
Doença de Alzheimer , Neuroblastoma , Humanos , Peptídeos beta-Amiloides/química , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/metabolismo , Cobre/química , Espécies Reativas de Oxigênio/metabolismo , Ácido Ascórbico/química
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