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1.
Small ; 20(8): e2305849, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37817350

RESUMEN

Layered double hydroxides (LDHs) with unique layered structure and atomic composition are limited in the field of electromagnetic wave absorption (EMA) due to their poor electrical conductivity and lack of dielectric properties. In this study, the EMA performance and anticorrosion of hollow derived LDH composites are improved by temperature control and composition design using ZIF-8 as a sacrifice template. Diverse regulation modes result in different mechanisms for EMA. In the temperature control process, chemical reactions tune the composition of the products and construct a refined structure to optimize the LDHs conductivity loss. Additionally, the different phase interfaces generated by the control components optimize the impedance matching and enhance the interfacial polarization. The results show that the prepared NCZ (Ni3ZnC0.7/Co3ZnC@C) has a minimum reflection loss (RLmin ) of -58.92 dB with a thickness of 2.4 mm and a maximum effective absorption bandwidth (EABmax ) of 7.36 GHz with a thickness of 2.4 mm. Finally, due to its special structure and composition, the sample exhibits excellent anticorrosion properties. This work offers essential knowledge for designing engineering materials derived from metal organic framework (MOF) with cutting-edge components and nanostructures.

2.
Small ; : e2403689, 2024 Aug 11.
Artículo en Inglés | MEDLINE | ID: mdl-39128133

RESUMEN

The excellent performance of electromagnetic wave absorbers primarily depends on the coordination among components and the rational design of the structure. In this study, a series of porous fibers with carbon nanotubes uniformly distributed in the shape of pine leaves are prepared through electrospinning technique, one-pot hydrothermal synthesis, and high-temperature catalysis method. The impedance matching of the nanofibers with a porous structure is optimized by incorporating melamine into the spinning solution, as it undergoes gas decomposition during high-temperature calcination. Moreover, the electronic structure can be modulated by controlling the NH4F content in the hydrothermal synthesis process. Ultimately, the Ni/Co/CrN/CNTs-CF specimen (P3C NiCrN12) exhibited superior performance, while achieving a minimum reflection loss (RLmin) of -56.18 dB at a thickness of 2.2 mm and a maximum absorption bandwidth (EABmax) of 5.76 GHz at a thickness of 2.1 mm. This study presents an innovative approach to fabricating lightweight, thin materials with exceptional absorption properties and wide bandwidth by optimizing the three key factors influencing electromagnetic wave absorption performance.

3.
Small ; : e2405874, 2024 Aug 29.
Artículo en Inglés | MEDLINE | ID: mdl-39206598

RESUMEN

Heterogeneous interfacial engineering has garnered widespread attention for optimizing polarization loss and enhancing the performance of electromagnetic wave absorption. A novel Kirkendall effect-assisted electrostatic self-assembly method is employed to construct a metal-organic framework (MOF, MIL-88A) decorated with Ni-Fe layered double hydroxide (LDH), forming a multilayer nano-cage coated with Ti3C2Tx. By modulating the surface adsorption of Ti3C2Tx on LDH, the heterointerfaces in MOF-LDH-MXene ternary composites exhibit excellent interfacial polarization loss. Additionally, the Ni-Fe LDH@Ti3C2Tx nano-cage exhibits a large specific surface area, abundant defects, and a large number of heterojunction structures, resulting in excellent electromagnetic wave absorption performance. The MIL-88A@Ni-Fe LDH@Ti3C2Tx-1.0 nano-cage achieves a reflection loss value of -46.7 dB at a thickness of 1.4 mm and an effective absorption bandwidth of 5.12 GHz at a thickness of 1.8 mm. The heterojunction interface composed of Ni-Fe LDH and Ti3C2Tx helps to enhance polarization loss. Additionally, Ti3C2Tx forms a conductive network on the surface, while the cavity between the MIL-88A core and the Ni-Fe LDH shell facilitates multiple attenuations by increasing the transmission path of internal incident waves. This work may reveal a new structural design of multi-component composites by heterointerfaces engineering for electromagnetic wave absorption.

4.
Small ; : e2404449, 2024 Jul 16.
Artículo en Inglés | MEDLINE | ID: mdl-39011980

RESUMEN

Currently, facing electromagnetic protection requirement under complex aqueous environments, the bacterial reproduction and organic dye corrosion may affect the composition and micro-structures of absorbers to weaken their electromagnetic properties. To address such problems, herein, a series of CoFe2O4@BCNPs (cobalt ferrite @ bio-carbon nanoparticles) composites are synthesized via co-hydrothermal and calcining process. The coupling of magnetic cobalt ferrite and dielectric bio-carbon derived from Apium can endow the composite multiple absorption mechanisms and matched impedance for effective microwave absorption, attaining a bandwidth of 8.12 GHz at 2.36 mm and an intensity of -49.85 dB at 3.0 mm. Due to the ROS (reactive oxygen species) stimulation ability and heavy metal ions of cobalt ferrite, the composite realizes an excellent antibacterial efficiency of 99% against Gram negative bacteria of Escherichia coli. Moreover, the loose porous layer of surface stacked bio-carbon can promote the adsorption of methylene blue for subsequent eliminating, a high removal rate of 90.37% for organic dye can be also achieved. This paper offers a new insight for rational design of composite's component and micro-structure to construct multi-functional microwave absorber for satisfying the electromagnetic protection demand in complicated environments.

5.
Sensors (Basel) ; 24(10)2024 May 14.
Artículo en Inglés | MEDLINE | ID: mdl-38793958

RESUMEN

Ion mobility spectrometry (IMS) has been widely studied and applied as an effective analytical technology for the on-site detection of volatile organic compounds (VOCs). Despite its superior selectivity compared with most gas sensors, its limited dynamic range is regarded as a major drawback, limiting its further application in quantitative measurements. In this work, we proposed a novel sample introduction method based on pulsed membrane adsorption, which effectively enhanced IMS's ability to measure analytes at higher concentrations. Taking N-methyl-2-pyrrolidone (NMP) as an example, this new sampling method expanded the dynamic range from 1 ppm to 200 ppm. The working principle and measurement strategy of this sampling method were also discussed, providing new insights for the design and application of IMS-based instruments.

6.
Small ; 19(52): e2304932, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37635102

RESUMEN

Reasonable composition design and controllable structure are effective strategies for harmonic electromagnetic wave (EMW) adsorption of multi-component composites. On this basis, the hybrid MoS2 /CoS2 /VN multilayer structure with the triple heterogeneous interface is prepared by simple stirring hydrothermal, which can satisfy the synergistic interaction between different components and obtain excellent EMW absorption performance. Due to the presence of multiple heterogeneous interfaces, MoS2 /CoS2 /VN composites will produce strong interfacial polarization, while the defects in the sample will become the center of polarization, resulting in dipole polarization. Due to the excellent structural design of MoS2 /CoS2 /VN composite material, MoS2 /CoS2 /VN composite material not only has good conductive loss and polarization loss, but also can maintain excellent stability in simulated seawater, and enhance corrosion resistance. The MoS2 /CoS2 /VN composite with dual functions of corrosion resistant and microwave absorption achieves a minimum reflection loss (RL) of -50.48 dB and an effective absorption bandwidth of up to 5.76 GHz, covering both the X-band and Ku-band. Finally, this study provides a strong reference for the development of EMW absorption materials based on transition metal nitrides.

7.
Chem Rec ; 20(2): 102-119, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31250979

RESUMEN

Multi-shelled hollow spheres metal oxides, namely materials with more than three shells, have attracted increasing attention due to their unique structure. The preparation methods of typical metal oxides including NiO, Co3 O4 and ZnO etc. have been summarized in this review. Simultaneously, the parameters that influence the ultimate morphologies, shell number as well as the compositions have also been discussed. The potential application fields in energy conversion and storage, electromagnetic wave absorption, photocatalysis that related to the unique structure are also highlighted. Finally, the future researches of multi-shelled hollow spheres metal oxides are further discussed.

8.
Molecules ; 25(15)2020 Jul 30.
Artículo en Inglés | MEDLINE | ID: mdl-32751631

RESUMEN

Nitrated-pyrazole-based energetic compounds have attracted wide publicity in the field of energetic materials (EMs) due to their high heat of formation, high density, tailored thermal stability, and detonation performance. Many nitrated-pyrazole-based energetic compounds have been developed to meet the increasing demands of high power, low sensitivity, and eco-friendly environment, and they have good applications in explosives, propellants, and pyrotechnics. Continuous and growing efforts have been committed to promote the rapid development of nitrated-pyrazole-based EMs in the last decade, especially through large amounts of Chinese research. Some of the ultimate aims of nitrated-pyrazole-based materials are to develop potential candidates of castable explosives, explore novel insensitive high energy materials, search for low cost synthesis strategies, high efficiency, and green environmental protection, and further widen the applications of EMs. This review article aims to present the recent processes in the synthesis and physical and explosive performances of the nitrated-pyrazole-based Ems, including monopyrazoles with nitro, bispyrazoles with nitro, nitropyrazolo[4,3-c]pyrazoles, and their derivatives, and to comb the development trend of these compounds. This review intends to prompt fresh concepts for designing prominent high-performance nitropyrazole-based EMs.


Asunto(s)
Nitratos/química , Nitrocompuestos/química , Pirazoles/química , Sustancias Explosivas/síntesis química , Sustancias Explosivas/química , Nitratos/síntesis química , Nitrocompuestos/síntesis química , Pirazoles/síntesis química , Termodinámica
9.
J Cardiovasc Electrophysiol ; 30(12): 2759-2766, 2019 12.
Artículo en Inglés | MEDLINE | ID: mdl-31599040

RESUMEN

BACKGROUND: Lifestyle and risk factor management may improve outcomes in patients with atrial fibrillation (AF). We aim to evaluate the prevalence of modifiable risk factors and how these factors impact clinical outcomes in patients with AF. METHODS AND RESULTS: Data on 17 898 AF cohort patients with AF enrolled between 2011 and 2016 was analyzed. A healthy lifestyle was defined as not smoking, not drinking, a healthy body mass index (BMI), untreated total cholesterol less than 200 mg/dL, untreated blood pressure (BP) less than 120/80 mm Hg, and untreated fasting plasma glucose (FPG) less than 100 mg/dL. The association between risk factors and risk of the composite endpoint of all-cause mortality and nonfatal ischemic stroke were assessed using Cox proportional hazards regression model. Only 4.0% of patients achieved a healthy lifestyle. In multivariate analysis, current smoking, a low BMI, not well-controlled FPG were independently and significantly associated with higher risk of all-cause mortality and nonfatal ischemic stroke, with corresponding hazard ratio (HR) estimates 1.22 (95% confidence interval [CI], 1.00-1.47), HR = 1.72 (95% CI, 1.34-2.20), and HR = 1.25 (95% CI, 1.06-1.46), respectively. High BP was also associated with higher risk with the outcomes (HR = 1.15, 95% CI, 1.00-1.34). Compared with patients with no risk factor, those who failed to maintained or achieved optimal risk factor control had a progressively higher risk of death and nonfatal ischemic stroke (HR for 1 risk factor = 1.44; 95% CI, 1.07-1.92; and more than 2 risk factors = 1.75; 95% CI, 0.99-3.09). CONCLUSIONS: Maintenance of well-controlled risk factors may substantially lower the risk of death and ischemic stroke in patients with AF.


Asunto(s)
Fibrilación Atrial/epidemiología , Estilo de Vida Saludable , Conducta de Reducción del Riesgo , Accidente Cerebrovascular/epidemiología , Anciano , Consumo de Bebidas Alcohólicas/epidemiología , Consumo de Bebidas Alcohólicas/prevención & control , Fibrilación Atrial/diagnóstico , Fibrilación Atrial/mortalidad , Fibrilación Atrial/terapia , Biomarcadores/sangre , Glucemia/metabolismo , Presión Sanguínea , Índice de Masa Corporal , China/epidemiología , Colesterol/sangre , Femenino , Humanos , Masculino , Persona de Mediana Edad , No Fumadores , Prevalencia , Pronóstico , Estudios Prospectivos , Factores Protectores , Sistema de Registros , Medición de Riesgo , Factores de Riesgo , Cese del Hábito de Fumar , Accidente Cerebrovascular/diagnóstico , Accidente Cerebrovascular/mortalidad , Accidente Cerebrovascular/prevención & control , Factores de Tiempo
10.
Exp Eye Res ; 169: 28-37, 2018 04.
Artículo en Inglés | MEDLINE | ID: mdl-29421327

RESUMEN

Our previous study has shown heme oxygenase-1 (HO-1) protects human lens epithelial cells (LECs) against H2O2-induced oxidative stress and apoptosis. Nrf2, the major regulator of HO-1, is triggered during the mutual induction of oxidative stress and ER stress. In response to ER stress, unfolded protein response (UPR) serves as a program of transcriptional and translational regulation mechanism with PERK involved. Both Nrf2 and ATF4 are activated as the downstream effect of PERK signaling coordinating the convergence of dual stresses. However, the ways in which Nrf2 interacting with ATF4 regulates deteriorated redox state have not yet been fully explored. Here, the transfected LECs with Nrf2 overexpression illustrated enhanced resistance in morphology and viability upon H2O2 treatment condition. Intracellular ROS accumulation arouses ER stress, initiating PERK dependent UPR and inducing the downstream signal Nrf2 and ATF4 auto-phosphorylation. Further, converging at target promoters, ATF4 facilitates Nrf2 with the expression of ARE-dependent phase II antioxidant and detoxification enzymes. According to either Nrf2 or ATF4 gene modification, our data suggests a novel interaction between Nrf2 and ATF4 under oxidative and ER stress, thus drives specific enzymatic and non-enzymatic reactions of antioxidant mechanisms maintaining redox homeostasis. Therapies that restoring Nrf2 or ATF4 expression might help to postpone LECs aging and age-related cataract formation.


Asunto(s)
Factor de Transcripción Activador 4/metabolismo , Estrés del Retículo Endoplásmico , Células Epiteliales/citología , Cristalino/citología , Factor 2 Relacionado con NF-E2/fisiología , Estrés Oxidativo , Western Blotting , Catalasa/metabolismo , Línea Celular , Citoprotección , Células Epiteliales/metabolismo , Citometría de Flujo , Técnica del Anticuerpo Fluorescente Indirecta , Glutatión/metabolismo , Humanos , Peróxido de Hidrógeno/toxicidad , Cristalino/metabolismo , Oxidantes/toxicidad , Fosforilación , Especies Reactivas de Oxígeno/metabolismo , Reacción en Cadena en Tiempo Real de la Polimerasa , Superóxido Dismutasa/metabolismo , Transfección , Respuesta de Proteína Desplegada/fisiología , eIF-2 Quinasa/metabolismo
11.
Inorg Chem ; 57(18): 11726-11731, 2018 Sep 17.
Artículo en Inglés | MEDLINE | ID: mdl-30148622

RESUMEN

Recently, development of a new type of anode material for lithium-ion batteries that possesses multielectron reaction, sufficient charge transfer, and restricted volume suppression has been considered a huge challenge. Herein, we find a simple hot-pressing method to incorporate polyoxometalate (POM)-based metal-organic frameworks (MOFs) onto three-dimensionally structured carbon cloth (CC), denoted as HP-NENU-5/CC, which immobilizes POMs into the MOFs avoiding the leaching of POMs and employs HP-NENU-5/CC as a flexible, conductive, and porous anode material. The HP-NENU-5/CC anode materials show outstanding electrochemical performance, exhibiting high reversible capacity (1723 mAh g-1 at 200 mA g-1), high rate capability (1072 mAh g-1 at 1000 mA g-1), and superior cycling stability (1072 mAh g-1 at 1000 mA g-1 after 400 cycles). Most importantly, the performance of HP-NENU-5/CC is the best among those of all reported POMs and MOF-based materials. In addition, we perform a comparative study for active materials coated on a two-dimensional current collector and CC, and our experimental results and analysis prove that the active material coated on CC does enhance the electrochemical performance.

12.
Int J Neurosci ; 124(12): 882-9, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25019276

RESUMEN

Epidemiologic studies have investigated the association of polymorphisms in 5-hydroxytryptamine type 2A receptor (5HT2A) gene and migraine susceptibility, but the results of those studies are inconclusive. To obtain a more systematic estimation of the association, we conducted a comprehensive search to examine all the eligible studies of 5HT2A polymorphisms and migraine risk. The odd ratios (ORs) with 95% confidence intervals (CIs) were used to determine the strength of the association. Publication bias was analyzed by Begg's funnel plots. Seven eligible studies regarding 5HT2A T102C and A-1438G polymorphisms with 721 cases and 713 controls were included in this meta-analysis. Overall, no significant associations were found between 5HT2A T102C (for T vs. C: OR = 1.029, 95% CI = 0.870-1.217, p = 0.739; for TT vs. CC: OR = 1.083, 95% CI = 0.760-1.544, p = 0.657; for TT + TC vs. CC: OR = 1.066, 95% CI = 0.802-1.416, p = 0.662; for TT vs. TC + CC: OR = 1.017, 95% CI = 0.774-1.336, p = 0.904) or A-1438G (for T vs. C: OR = 0.996, 95% CI = 0.726-1.365, p = 0.979; for TT vs. CC: OR = 0.983, 95% CI = 0.511-1.891, p = 0.960; for TT + TC vs. CC: OR = 1.118, 95% CI = 0.654-1.910, p = 0.684; for TT vs. TC + CC: OR = 0.890, 95% CI = 0.528-1.499, p = 0.661) polymorphisms and migraine risk. The further subgroup analysis by ethnicity, assay and disease type also found no significant association using four genetic models. Meanwhile, the publication bias analysis suggests that there is no publication bias in these studies. In conclusion, our current meta-analysis implies that 5HT2A T102C and A-1438G polymorphisms may be not risk factors in the pathogenesis of migraine.


Asunto(s)
Predisposición Genética a la Enfermedad/genética , Trastornos Migrañosos/diagnóstico , Trastornos Migrañosos/genética , Polimorfismo de Nucleótido Simple/genética , Receptor de Serotonina 5-HT2A/genética , Estudios de Casos y Controles , Estudios de Asociación Genética/métodos , Humanos
13.
Int J Biol Macromol ; 273(Pt 1): 133052, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38857732

RESUMEN

Scalable and highly efficient bamboo whitening remains a great challenge. Herein, an effective bamboo whitening strategy is proposed based on photocatalyzed oxidation, which involves H2O2 infiltration and UV illumination. The as-prepared white bamboo well maintains the nature structure of natural bamboo and demonstrates high whiteness and superior mechanical properties. The absorbance value is significantly decreased to 3.5 and the transmittance is increased to 0.04 % in UV-visible wavelength range due to the removal of light-absorbing chromospheres of lignin, resulting in a high whiteness when the UV illumination time is 8 h. In addition, the white bamboo displays a high tensile strength of 30 MPa and a high flexural strength of 36 MPa due to the well-preserved lignin units (lignin preservation is about 89 %). XRD patterns and analysis show that photocatalyzed oxidation has no effect on the crystal parameters of cellulose. Compared with the traditional bamboo whitening technology, our photocatalyzed oxidation strategy demonstrates significant advantage including chemical and time conservation, high efficiency, environment friendliness, and mechanical robustness. This highly efficient and environmentally friendly photocatalyzed oxidation strategy for the fabrication of white bamboo may pave the way of bamboo-based energy-efficient structural materials for engineering application.


Asunto(s)
Lignina , Oxidación-Reducción , Lignina/química , Catálisis , Sasa/química , Peróxido de Hidrógeno/química , Resistencia a la Tracción , Rayos Ultravioleta , Procesos Fotoquímicos , Color , Poaceae/química
14.
Quant Imaging Med Surg ; 14(8): 5434-5442, 2024 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-39144007

RESUMEN

Background: Extravaginal testicular torsion has profound clinical implications in neonates, but its ultrasound characteristics may vary at different disease stages. The purpose of this study was to identify the ultrasound characteristics of neonatal extravaginal testicular torsion and their diagnostic value at different disease stages. Methods: A retrospective analysis of the clinical and ultrasound examination data of 20 infants aged 1-75 days with surgically and pathologically confirmed unilateral extravaginal testicular torsion (10 right, 10 left) was conducted. The infants were divided into three stages based on the ultrasound characteristics: double-ring effusion, calcification of the tunica vaginalis, and testicular atrophy. Results: In the double-ring effusion stage, the affected testicles were enlarged with axial abnormalities, with the parenchymal testicular blood flow signal significantly reduced or absent. Twisted paratesticular masses and a "double-ring effusion sign" were visible. In the tunica vaginalis calcification stage, the affected testicles were slightly smaller, with axial abnormalities, absent blood flow signals in the testicular parenchyma, and strong echogenicity of the tunica vaginalis. In the testicular atrophy stage, the affected testicles were markedly smaller, with enhanced echogenicity in the tunica vaginalis and parenchyma, and absent blood flow signal in the testicular parenchyma. The volumes of the affected testicles gradually decreased from the stage of double-ring effusion to that of tunica vaginalis calcification, and then to testicular atrophy (P<0.05). Conclusions: Neonatal extravaginal testicular torsion at different disease stages has distinct ultrasound features, and color doppler ultrasound plays an important role in the diagnosis and treatment of extravaginal testicular torsion.

15.
Heliyon ; 10(12): e33145, 2024 Jun 30.
Artículo en Inglés | MEDLINE | ID: mdl-39022044

RESUMEN

CD19 is a surface antigen on B cells that regulates B cell activation and proliferation, participating in B cell signaling. It is expressed in all B cell lineage tumor diseases, making CD19 a significant marker for detecting B cell tumor diseases and an important target for related immunotherapies. In recent years, with the deepening research on canine and feline diseases and the establishment of animal models, the demand for cat CD19 monoclonal antibodies (mAbs) has been steadily increasing. We successfully prepared cat CD19-specific monoclonal antibodies using a KLH-conjugated cat CD19 peptide as an antigen and optimized the antibody production method. The obtained monoclonal antibodies' molecular and cellular affinities were identified using CD19 peptides, eukaryotic overexpressed proteins, and peripheral blood mononuclear cells (PBMCs). The results indicate that the CD19-3H9 and CD19-8A7 monoclonal antibodies prepared in this study specifically bind to the CD19 molecule, demonstrating their suitability for use in ELISA, Western blot, and cell assays. This study successfully produced cat CD19 monoclonal antibodies with specificity and optimized the antibody preparation method, laying the foundation for the diagnosis and targeted drug combination therapy of B cell tumor diseases in both humans and pets.

16.
J Colloid Interface Sci ; 678(Pt A): 648-655, 2024 Aug 26.
Artículo en Inglés | MEDLINE | ID: mdl-39216392

RESUMEN

Electromagnetic wave absorption materials (EWAMs) have become an effective means to address electromagnetic (EM) radiation and enhance stealth technology, among which aerogels are valued for their lightweight nature and excellent designability. This study utilized environmentally friendly preparation and in-situ reduction techniques to fabricate bacterial cellulose (BC) / reduced graphene oxide (RGO) aerogels, achieving tailored EM wave loss capabilities by controlling the reduction time of ascorbic acid. Benefitting from the effects of freeze-casting, BC winding, hydrogen bond, and RGO layers coupling, the aerogel maintains their original structure after reduction and exhibits satisfactory EM wave absorption. The minimum reflection loss (RLmin) is -38.52 dB, with an effective absorption bandwidth (EAB) of 6.68 GHz and a maximum radar cross section (RCS) reduction of 44.69 dBsm. Additionally, the aerogel's lightweight (a low density of 9.03 mg/cm3) and outstanding thermal insulation properties enable it to adapt to complex conditions. Thus, the study provides a novel approach for the construction of industrialized and sustainable RGO-based EWAMs.

17.
J Colloid Interface Sci ; 676: 217-226, 2024 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-39024822

RESUMEN

Developing multifunctional materials which could simultaneously possess anti-bacterial ability and electromagnetic (EM) absorption ability during medical care is quite essential since the EM waves radiation and antibiotic-resistant bacteria are threatening people's health. In this work, the multifunctional carbon fiber/Ti3C2Tx MXene (CM) were synthesized through repeated dip-coating and following in-situ growth method. The as-fabricated CF/MXene displayed outstanding EM wave absorption and highly efficient photothermal converting ability. The minimum reflection loss (RL) of -57.07 dB and ultra-broad absorption of 7.74 GHz could be achieved for CM composites. By growth of CoNi-layered double hydroxides (LDHs) sheets onto MXene, the absorption bandwidth for carbon fiber/Ti3C2Tx MXene layered double hydroxides (CML) could be reach 5.44 GHz, which could cover the whole Ku band. The excellent photothermal effect endow the CM composites with excellent antibacterial performance. The antibacterials tests indicated that nearly 100 % bactericidal efficiency against E. acoil and S. aureus was obtained for the CM composite after exposure to near-infrared region (NIR) irradiation. This work provides a promising candidate to combat medical device-related infections and EM pollution.


Asunto(s)
Antibacterianos , Fibra de Carbono , Escherichia coli , Rayos Infrarrojos , Staphylococcus aureus , Antibacterianos/farmacología , Antibacterianos/química , Antibacterianos/síntesis química , Staphylococcus aureus/efectos de los fármacos , Escherichia coli/efectos de los fármacos , Fibra de Carbono/química , Radiación Electromagnética , Pruebas de Sensibilidad Microbiana , Titanio/química , Titanio/farmacología , Rayos Láser , Tamaño de la Partícula , Propiedades de Superficie
18.
Nanomicro Lett ; 17(1): 23, 2024 Sep 27.
Artículo en Inglés | MEDLINE | ID: mdl-39331208

RESUMEN

Currently, the demand for electromagnetic wave (EMW) absorbing materials with specific functions and capable of withstanding harsh environments is becoming increasingly urgent. Multi-component interface engineering is considered an effective means to achieve high-efficiency EMW absorption. However, interface modulation engineering has not been fully discussed and has great potential in the field of EMW absorption. In this study, multi-component tin compound fiber composites based on carbon fiber (CF) substrate were prepared by electrospinning, hydrothermal synthesis, and high-temperature thermal reduction. By utilizing the different properties of different substances, rich heterogeneous interfaces are constructed. This effectively promotes charge transfer and enhances interfacial polarization and conduction loss. The prepared SnS/SnS2/SnO2/CF composites with abundant heterogeneous interfaces have and exhibit excellent EMW absorption properties at a loading of 50 wt% in epoxy resin. The minimum reflection loss (RL) is - 46.74 dB and the maximum effective absorption bandwidth is 5.28 GHz. Moreover, SnS/SnS2/SnO2/CF epoxy composite coatings exhibited long-term corrosion resistance on Q235 steel surfaces. Therefore, this study provides an effective strategy for the design of high-efficiency EMW absorbing materials in complex and harsh environments.

19.
J Colloid Interface Sci ; 633: 92-101, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36436351

RESUMEN

Polyaniline, a modified conductive polymer, has been widely studied in the field of electromagnetic (EM) wave absorption due to its excellent dielectric and conductive properties. However, it has limited applications due to its hard molding and processing, and poor mechanical stability. In this study, ice crystals with rapid directional growth were used as templates for polymerization to obtain polymer precursors with directional channels, and then ternary polymer sponges with oriented pore channels were designed and synthesized using a secondary template method. The Poisson's ratio of the study material reaches -1.52 and it absorbs 5.1 mJ/cm3 energy in a single compression cycle at 25% longitudinal strain. Also, the material has more than 90% absorption efficiency for X-band EM waves at a thickness of 4 mm. The flexibility of polymer molecular chains and the arrangement of oriented pores are the reasons for the negative Poisson's ratio property of the material, while the key to the loss of EM energy in the absorption process is the conversion of quinone bipolaron to monopolaron structure. Due to its large-scale green preparation with ice crystal as the template, this lightweight and robust material system are ideal for absorbing EM waves under extreme conditions.

20.
J Colloid Interface Sci ; 651: 494-503, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37556906

RESUMEN

In the field of electromagnetic (EM) wave absorption, intrinsic conductive polymers with conjugated long-chain structures, such as polyaniline (PANI) and polypyrrole (PPy), have gained widespread use due to their remarkable electrical conductivity and loss ability. However, current research in this area is limited to macroscopic descriptions of the absorption properties of these materials and the contribution of various components to the absorption effect. There has been insufficient exploration of the impact mechanisms of polymer aggregation states on the material's absorption performance and mechanism. To address this, a series of flexible PANI sponge absorbers with different molecular weights and aggregation states were prepared. By carefully controlling the crystallinity and other aggregation characteristics of PANI through the adjustment of its preparation conditions, we were able to influence its electrical conductivity and electromagnetic parameters, thereby achieving control over the material's absorption properties. The resulting PANI sponge absorbers exhibited an effective absorption bandwidth (EAB) that covered the entire X-band at a thickness of 3.2 mm. This study comprehensively explores the absorption mechanisms of conductive polymer absorbers, starting from the microstructure of PANI, and providing a more complete theoretical support for the research and promotion of polymer absorbers.

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