Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 11 de 11
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Small ; : e2402443, 2024 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-38845082

RESUMO

The development and application of lithium-ion batteries present a dual global prospect of opportunity and challenge. With conventional energy sources facing reserve shortages and environmental issues, lithium-ion batteries have emerged as a transformative technology over the past decade, owing to their superior properties. They are poised for exponential growth in the realms of electric vehicles and energy storage. The cathode, a vital component of lithium-ion batteries, undergoes chemical and electrochemical reactions at its surface that directly impact the battery's energy density, lifespan, power output, and safety. Despite the increasing energy density of lithium-ion batteries, their cathodes commonly encounter surface-side reactions with the electrolyte and exhibit low conductivity, which hinder their utility in high-power and energy-storage applications. Surface engineering has emerged as a compelling strategy to address these challenges. This paper meticulously examines the principles and progress of surface engineering for cathode materials, providing insights into its potential advancements and charting its development trajectory for practical implementation.

2.
Small ; 20(3): e2304914, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37679061

RESUMO

Robust, ultrathin, and environmental-friendliness papers that synergize high-efficiency electromagnetic interference (EMI) shielding, personal thermal management, and wearable heaters are essential for next-generation smart wearable devices. Herein, MXene nanocomposite paper with a nacre-like structure for EMI shielding and electrothermal/photothermal conversion is fabricated by vacuum filtration of Ti3 C2 Tx MXene and modified sawdust. The hydrogen bonding and highly oriented structure enhance the mechanical properties of the modified sawdust/MXene composite paper (SM paper). The SM paper with 50 wt% MXene content shows a strength of 23 MPa and a toughness of 13 MJ·M-3 . The conductivity of the SM paper is 10 195 S·m-1 , resulting in an EMI shielding effectiveness (SE) of 67.9 dB and a specific SE value (SSE/t) of 8486 dB·cm2 ·g-1 . In addition, the SM paper exhibits excellent thermal management performance including high light/electro-to-thermal conversion, rapid Joule heating and photothermal response, and sufficient heating stability. Notably, the SM paper exhibits low infrared emissivity and distinguished infrared stealth performance, camouflaging a high-temperature heater surface of 147-81 °C. The SM-based e-skin achieves visualization of Joule heating and realizes human motions monitoring. This work presents a new strategy for designing MXene-based wearable devices with great EMI shielding, artificial intelligence, and thermal management applications.

3.
Molecules ; 28(12)2023 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-37375249

RESUMO

The large-scale use of sulfonamide antimicrobials in human and veterinary medicine has seriously endangered the ecological environment and human health. The objective of this study was to develop and validate a simple and robust method for the simultaneous determination of seventeen sulfonamides in water using ultra-high performance liquid chromatography-tandem mass spectrometry coupled with fully automated solid-phase extraction. Seventeen isotope-labeled internal standards for sulfonamides were used to correct matrix effects. Several parameters affecting extraction efficiency were systematically optimized, and the enrichment factors were up to 982-1033 and only requiring about 60 min per six samples. Under the optimized conditions, this method manifested good linearity (0.05-100 µg/L), high sensitivity (detection limits: 0.01-0.05 ng/L), and satisfactory recoveries (79-118%) with acceptable relative standard deviations (0.3-14.5%, n = 5). The developed method can be successfully utilized for the determination of 17 sulfonamides in pure water, tap water, river water, and seawater. In total, six and seven sulfonamides were detected in river water and seawater, respectively, with a total concentration of 8.157-29.676 ng/L and 1.683-36.955 ng/L, respectively, and sulfamethoxazole was the predominant congener.


Assuntos
Anti-Infecciosos , Espectrometria de Massas em Tandem , Humanos , Espectrometria de Massas em Tandem/métodos , Água , Cromatografia Líquida de Alta Pressão/métodos , Cromatografia Líquida , Sulfanilamida , Anti-Infecciosos/análise , Sulfonamidas/análise , Extração em Fase Sólida/métodos
4.
Int J Biol Macromol ; 242(Pt 3): 124895, 2023 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-37196710

RESUMO

The remediation of heavy crude oil spills is a global challenge because frequent crude oil spills cause long-term damage to local living beings and marine ecosystems. Herein, a solar-driven and Joule-driven self-heated aerogel were developed as an all-weather adsorbent to efficiently absorb crude oil by obviously decreasing the viscosity of crude oil. The cellulose nanofiber (CNF)/MXene/luffa (CML) aerogel was fabricated via a simple freeze-drying method using CNF, MXene, and luffa as raw materials, and then coated with a layer of polydimethylsiloxane (PDMS) to make it hydrophobic and further increase oil-water selectivity. The aerogel can quickly reach 98 °C under 1 sun (1.0 kW/m2), which remains saturated temperature after 5 times photothermal heating/cooling cycles, indicating that the aerogel has great photothermal conversation capability and stability. Meanwhile, the aerogel can also rapidly rise to 110.8 °C with a voltage of 12 V. More importantly, the aerogel achieved the highest temperature of 87.2 °C under outdoor natural sunlight, providing a possibility for promising applications in practical situations. The remarkable heating capability enables the aerogel to decrease the viscosity of crude oil substantially and increase the absorption rate of crude oil by the physical capillary action. The proposed all-weather aerogel design provides a sustainable and promising solution for cleaning up crude oil spills.


Assuntos
Luffa , Nanofibras , Petróleo , Nanofibras/química , Celulose/química , Ecossistema , Tempo (Meteorologia)
5.
ACS Appl Mater Interfaces ; 15(20): 24933-24947, 2023 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-37165637

RESUMO

Conductive hydrogels have good prospects in the fields of flexible electronic devices and artificial intelligence due to their biocompatibility, durability, and functional diversity. However, the process of hydrogel polymerization is time-consuming and energy-consuming, and freezing at zero temperature is inevitable, which seriously hinders its applications and working life. Herein, zwitterionic conductive hydrogels with self-adhesive and antifreeze properties were prepared in one minute by introducing two-dimensional (2D) MXene nanosheets into the autocatalytically enhanced system composed of tannic acid-modified cellulose nanofibers and zinc chloride. The system has strong environmental applicability (-60 to 40 °C), good stretchability (ductility ≈ 980%), durable adhesion (even after 30 days of exposure to air), and strong electrical conductivity (20 °C, 30 mS cm-1). By virtue of these advantages, the prepared zwitterionic hydrogels can be developed into flexible strain sensors to monitor large human movements and subtle physiological signals over a wide temperature range and to capture signals from handwriting and voice recognition. In addition, multiple flexible sensors can be assembled into a three-dimensional (3D) array, which can detect the magnitude and spatial distribution of strain or force. These results demonstrate that the prepared zwitterionic hydrogels have promising applications in the fields of medical monitoring and artificial intelligence.

6.
J Colloid Interface Sci ; 645: 306-318, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37150004

RESUMO

Interfacial solar steam generation (ISSG) is considered to be an attractive technique to address the water shortage. However, developing a sustainable thermal management, salt rejection, and excellent mechanical strength ISSG device for long-term stability desalination is still a challenge. Herein, a biomass ISSG device with superb mechanical properties was prepared by introducing a luffa sponge as the skeleton and constructing the MXene/cellulose nanofibers (CNFs) aerogels via freeze-drying. The Janus MXene-decorated CNFs/luffa (JMCL) aerogels integrated the multifunction of fast water transport, good thermal management, and efficient photothermal conversion in a single module, to achieve high-efficiency desalination. 3D Janus structure endowed the JMCL aerogel with opposite wettability, which is feasible to construct the localized photothermal generation and self-floating. The mechanical strength of JMCL aerogels is 437 times that of MXene/CNFs aerogels. The JMCL aerogels delivered a water evaporation rate of 1.40 kg m-2h-1 and an efficiency of 91.20% under 1 sun illumination. The excellent salt resistance during 24 h working and long-term solar vapor generation of up to 28 days were achieved. The multifunctional JMCL aerogels with 3D Janus structure offer new insights for developing good durability and eco-friendly biopolymer-based steam generators.

7.
Artigo em Inglês | MEDLINE | ID: mdl-35940057

RESUMO

The widespread use of quinolones in humans and animals has become a major threat to public health. In this study, a simple, rapid, sensitive, and high throughput method based on automatic solid-phase extraction and isotope dilution ultra-performance liquid chromatography tandem mass spectrometry was described for the determination of trace quinolones in environmental water. The proposed automated solid-phase extraction method was initially optimized, and the optimum experimental conditions found were 1 L water sample with 0.5 g/L Na2EDTA (pH 3) extracted and enriched by CNW Poly-Sery HLB cartridge at a flow rate of 50 mL/min and eluted by 8 mL of methanol. The linearity of the method ranged from 0.05 to 100 µg/L for 15 quinolones, with correlation coefficients ranging from 0.9993 to 0.9999. The limits of detection were in the low ng/L level, ranging from 0.005 to 0.051 ng/L. Finally, the optimized method was applied for determining trace levels of 15 quinolones in Wahaha pure water, tap water, river water, and seawater samples with good recoveries of 93 %-119 % and satisfactory relative standard deviations of 0.1 %-13.9 %. Fourteen quinolones were detected, and ofloxacin was the predominant congener in river water and seawater.


Assuntos
Quinolonas , Poluentes Químicos da Água , Animais , Antibacterianos/análise , Cromatografia Líquida de Alta Pressão/métodos , Cromatografia Líquida/métodos , Humanos , Isótopos , Limite de Detecção , Quinolonas/análise , Extração em Fase Sólida/métodos , Espectrometria de Massas em Tandem/métodos , Água , Poluentes Químicos da Água/análise
8.
Chemistry ; 26(28): 6234-6239, 2020 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-32181931

RESUMO

Converting CO2 into high-value chemicals has been regarded as an important solution for a sustainable low-carbon economy. In this work, we have theoretically designed an innovative strategy for the absorption and activation of CO2 by the electride N3Li, that is, 1,3,5(2,6)-tripyridinacyclohexaphane (N3) intercalated by lithium. DFT computations showed that the interaction of CO2 with N3Li leads to the catalytic complex N3Li(η2 -O2 C), which can initiate the radical-controlled reduction of another CO2 to form organic acids through radical reactions in the gas phase. The CO2 reduction consists of four steps: (1) The formation of N3Li(η2 -O2 C) through the combination of N3Li and CO2 , (2) hydrogen abstraction from RH (R=H, CH3 , and C2 H5 ) by N3Li(η2 -O2 C) to form the radical R. and N3Li(η2 -O2 C)H, (3) the combination of CO2 and the radical R. to form RCOO. , and (4) intermolecular hydrogen transfer from the intermediate N3Li(η2 -O2 C)H to RCOO. . In the whole reaction process, the CO2 moiety in the complex N3Li(η2 -O2 C) maintains a certain radical character at the carbon atom of CO2 and plays a self-catalyzing role. This work represents the first example of electride-sponsored radical-controlled CO2 reduction, and thus provides an alternative strategy for CO2 conversion.

9.
J Phys Condens Matter ; 32(8): 085802, 2020 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-31675727

RESUMO

Effectively controlling and modulating the electronic structure and magnetism is critical for the application of spintronics devices which based on two dimensional (2D) materials. Herein, by using density functional theory (DFT), we investigate synergistic effect of Mn (or Fe) doping and biaxial strain on electronic structure and magnetism of arsenene system. Unstrained Mn-doped arsenene exhibits a half-metallic state, but unstrained Fe-doped structure is narrow and direct band-gap semiconductor. The emerging spin splitting is caused by orbital hybridization of 4p -3d. Therefore, by the Mn and Fe doing, the systems produce a net magnetic moment of 4.00 and 1.00 [Formula: see text], respectively. Particularly, the room temperature ferromagnetism (RTFM) can be achieved in two doping structures. Under the condition of coexistence of impurity atom and biaxial strain, for the Mn doping, the systems are still half-metal materials and magnetism remain stable. While the Fe-doped system translates into a magnetic metal state due to the closure of band gap under the tensile strain of 4%. And the magnetic moments have a sudden transition, increase to 3.92, 5.00 and 5.00 [Formula: see text] under strains of 4%, 6% and 8%, respectively. In addition, the electronic structure and magnetism of Fe doping can also be affected by doping concentration. This work broadens the way about application of arsenene-based spintronic devices.

10.
Zhongguo Yi Liao Qi Xie Za Zhi ; 42(6): 413-416, 2018 Nov 30.
Artigo em Chinês | MEDLINE | ID: mdl-30560618

RESUMO

Numerical simulation is a powerful technology for photoacoustic imaging (PAI) in both theory studies and practical applications. In this paper, a simulation platform for PAI was designed and implemented based on Matlab. The simulation platform utilized finite element method (FEM) and k-space pseudospectral method to calculate the forward and inverse problem of PAI. And a graphical user interface (GUI) was realized. Structural design, work process and other operating details of the platform was also provided. By compared with theoretical temporal waveform of photoacoustic signal and reconstruction results of COMSOL, the validity and reliability was verified. And a reliable simulation tool was proposed for PAI.


Assuntos
Algoritmos , Análise de Elementos Finitos , Técnicas Fotoacústicas , Simulação por Computador , Reprodutibilidade dos Testes
11.
J Sep Sci ; 39(19): 3818-3826, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27501328

RESUMO

Graphene-Fe3 O4 nanoparticles were prepared using one-step solvothermal method and characterized by X-ray diffraction, FTIR spectroscopy, scanning electron microscopy, and vibrating sample magnetometry. The results demonstrated that Fe3 O4 nanoparticles were homogeneously anchored on graphene nanosheets. The as-synthesized graphene-Fe3 O4 nanoparticles were employed as sorbent for magnetic solid-phase extraction of sulfonamides in milk prior to capillary electrophoresis analysis. The optimal capillary electrophoresis conditions were as follows: 60 mmol/L Na2 HPO4 containing 2 mmol/L ethylenediaminetetraacetic acid disodium salt and 24% v/v methanol as running buffer, separation voltage of 14 kV, and detection wavelength of 270 nm. The parameters affecting extraction efficiency including desorption solution, the amount of graphene-Fe3 O4 nanoparticles, extraction time, and sample pH were investigated in detail. Under the optimal conditions, good linearity (5-200 µg/L) with correlation coefficients ≥0.9910 was obtained. The limits of detection were 0.89-2.31 µg/L. The relative standard deviations for intraday and interday analyses were 4.9-8.5 and 4.0-9.0%, respectively. The proposed method was successfully applied to the analysis of sulfonamides in milk samples with recoveries ranging from 62.7 to 104.8% and relative standard deviations less than 10.2%.


Assuntos
Eletroforese Capilar/métodos , Grafite/química , Leite/química , Extração em Fase Sólida/métodos , Sulfonamidas/química , Sulfonamidas/isolamento & purificação , Adsorção , Animais , Bovinos , Contaminação de Alimentos/análise , Nanopartículas de Magnetita/química , Extração em Fase Sólida/instrumentação
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...