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1.
Environ Technol ; : 1-14, 2024 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-39090069

RESUMEN

Dissolved organic pollutants caused by paints, detergents, herbicides, and toxins cannot be removed by conventional water treatment processes such as filtration. Different figures of activated carbon such as carbon nanotubes (CNTs) are substances to obliterate these contaminants. Although these CNTs have higher ability to decompose organic contaminants, using the slurry form of CNTs is not suitable due to the removal requirement at the end of the treatment procedure. In this study, upgraded CNTs attached to particles of sand filters (CNTsand) were synthesised and applied to remove dissolved organic pollutants. The results revealed the high capacity of the CNTsand to extract organic contaminants. The column test with natural water compared to the distilled water had a more extended breakpoint, higher adsorption capacity, and consequently, further removal efficiency, such that for the surface area loading rate of 4.8 ml/min, the breakpoint increased from 739 minutes to 936 minutes as well as the volume of passed water grew from 3546 ml to 4493 ml; Therefore, the maximum adsorption capacity was enhanced from 67.3 mg/g to 89.5 mg/g. In conclusion, the adequacy and efficiency of the upgraded nanotube coating on sand grains to remove organic pollutants were confirmed.

2.
Artículo en Inglés | MEDLINE | ID: mdl-39099309

RESUMEN

Triple-negative breast cancer (TNBC) has short survival rates. This study aimed to prepare a novel formula of sorafenib, carbon nanotubes (CNTs), and folic acid to be tested as a drug delivery system targeting versus TNBC compared with free sorafenib and to evaluate the formula stability, in vitro pharmacodynamic, and in vivo pharmacokinetic properties. The formula preparation was done by the synthesis of polyethylene glycol bis amine linker, CNT PEGylation, folic acid attachment, and sorafenib loading. The prepared formula has been characterized using X-ray diffraction, Flourier-transform infrared, 1HNMR, UV, high resolution-transmission electron microscope, field emission scanning electron microscopy, and Zeta potential. In vitro studies included drug release determination, MTT assay, flow cytometry to determine the apoptotic stage with percent, cell cycle analysis, and apoptotic marker assays for caspase-3, 8, 9, cytochrome c, and BCL-2. The in vivo study was performed to determine bioavailability and half-life in rats. The in vitro MTT antiproliferative assay revealed that the formula was threefold more cytotoxic toward TNBC cells than free sorafenib, and the flow cytometry showed a significant increase in apoptosis and necrosis. The formula has a greater inhibitory effect on BCL-2 and a lessening effect on cytochrome c and caspases 3, 8, and 9 than free sorafenib. In vivo experiments proved that our novel formula was superior to free sorafenib by increasing bioavailability by eight times and prolonging the half-life by three times. These results confirmed the successful preparation of the desired formula with better pharmacodynamic and pharmacokinetic properties. These promising results may show a novel therapeutic strategy for TNBC patients.

3.
Materials (Basel) ; 17(15)2024 Aug 05.
Artículo en Inglés | MEDLINE | ID: mdl-39124530

RESUMEN

It is expected that composites made of carbon nanotubes (CNT) and copper (Cu) display both mechanical and electrical properties, but the low damage dispersion and high-quality composite of high-content CNTs have always been research difficulties. In this paper, high-content CNTs/Cu composites were prepared. The effects of the sintering method, sintering temperature, directional rolling and the CNTs' content on the relative density, hardness and electrical conductivity of the composites were studied. The uniform dispersion of high-content CNTs in Cu matrix was achieved by ball milling, sintering and rolling, and the processes did not cause more damage to the CNTs. The properties of composites prepared by spark plasma sintering (SPS) and vacuum hot pressing sintering (HPS) were compared, and the optimum process parameters of SPS were determined. When the CNTs' content is 2 wt.%, the hardness is 134.9 HBW, which is still 2.3 times that of pure Cu, and the conductivity is the highest, reaching 78.4%IACS. This study provides an important reference for the high-quality preparation and performance evaluation of high-content CNTs/Cu composites.

4.
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.

5.
Bioelectrochemistry ; 160: 108774, 2024 Jul 06.
Artículo en Inglés | MEDLINE | ID: mdl-38981325

RESUMEN

Salivary α-amylase (α-ALS) has drawn attention as a possible bioindicator for dental caries. Herein, combining the synergistic properties of multi-walled carbon nanotubes (MWCNTs), ß-cyclodextrin (ß-CD) and starch, an electrochemical sensor is constructed employing ferrocene (FCN) as an electrochemical indicator to oversee the progression of the enzymatic catalysis of α-ALS. The method involves a two-step chemical reaction sequence on a screen-printed carbon electrode (SPCE). X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, Field emission scanning electron microscope (FE-SEM), and Dynamic light scattering (DLS) were used to characterize the synthesized material, while Static water Contact angle measurements, cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS) were performed to monitor each step of sensor fabrication. The electrochemical sensor permitted to detect α-ALS within the linear range of 0.5-280 U mL-1, revealing detection (LOD), and quantification (LOQ) values of 0.041 U mL-1, and 0.159 U mL-1, respectively. Remarkably, the sensor demonstrated exceptional specificity and selectivity, effectively discriminating against other interfering substances in saliva. Validation of the method involved analyzing α-ALS levels in artificial saliva with an accuracy range of 97 % to 103 %, as well as in real clinical saliva samples across various age groups.

6.
Adv Mater ; : e2407329, 2024 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-38966893

RESUMEN

Touch control intention recognition is an important direction for the future development of human-machine interactions (HMIs). However, the implementation of parallel-sensing functional modules generally requires a combination of different logical blocks and control circuits, which results in regional redundancy, redundant data, and low efficiency. Here, a location-and-pressure intelligent tactile sensor (LPI tactile sensor) unprecedentedly combined with sensing, computing, and logic is proposed, enabling efficient and ultrahigh-resolution action-intention interaction. The LPI tactile sensor eliminates the need for data transfer among the functional units through the core integration design of the layered structure. It actuates in-sensor perception through feature transmission, fusion, and differentiation, thereby revolutionizing the traditional von Neumann architecture. While greatly simplifying the data dimensionality, the LPI tactile sensor achieves outstanding resolution sensing in both location (<400 µm) and pressure (75 Pa). Synchronous feature fusion and decoding support the high-fidelity recognition of action and combinatorial logic intentions. Benefiting from location and pressure synergy, the LPI tactile sensor demonstrates robust privacy as an encrypted password device and interaction intelligence through pressure enhancement. It can recognize continuous touch actions in real time, map real intentions to target events, and promote accurate and efficient intention-driven HMIs.

7.
Spectrochim Acta A Mol Biomol Spectrosc ; 322: 124800, 2024 Jul 09.
Artículo en Inglés | MEDLINE | ID: mdl-39024784

RESUMEN

Scaffolds acting as an artificial matrix for cell proliferation are one of the bone tissue engineering approaches to the treatment of bone tissue defects. In the presented study, novel multicomponent scaffolds composed of a poly(ε-caprolactone) (PCL), phenolic compounds such as tannic (TA) and gallic acids (GA), and nanocomponents such as silica-coated magnetic iron oxide nanoparticles (MNPs-c) and functionalized multi-walled carbon nanotubes (CNTs) have been produced as candidates for such artificial substitutes. Well-developed interconnected porous structures were observed using scanning electron microscopy (SEM). Raman spectra showed that the highly crystalline nature of PCL was reduced by the addition of nanoadditives. In the case of scaffolds containing MNPs-c and TA, the formation of a Fe-TA complex was concluded because characteristic bands of chelation of the Fe3+ ion by phenolic catechol oxygen appeared. It was found that the necessary conditions for the crystallization of the PCL/MNPs-c/TA are for the catechol groups to be able to penetrate the porous silica shell of MNPs-c, as during experiment with MNPs-c and TA without polymer, no such complexation was observed. Moreover, the number of catechol groups, the spatial structure and molecular size of this phenolic compound are also crucial for complexation process because GA does not form complexes. Therefore, the PCL/CNTs/MNPs-c/TA scaffolds are interesting candidates to consider for their possible medical applications.

8.
Int J Biol Macromol ; 276(Pt 1): 133927, 2024 Jul 19.
Artículo en Inglés | MEDLINE | ID: mdl-39025191

RESUMEN

As is well known, cellulose, as a natural polymer material with abundant reserves, plays an irreplaceable role as the major raw material in energy and chemical-related fields. With the continuous advancement of technology, native single-component cellulose is often unsatisfactory for practical applications, constructing composites is an effective means of expanding the applications. When compounded with other ingredients to prepare composites, cellulose usually needs to be dissolved and regenerated to obtain good dispersion. Current studies have revealed that cellulose is insoluble in conventional solvents, and the limited types of solvent systems that can dissolve cellulose tend to degrade the cellulose during the dissolution process, altering the cellulose properties. Ionic liquids (ILs) are a class of solvents that are capable of dissolving cellulose without adversely affecting the cellulose during the dissolution process, such as degradation. Graphene and carbon nanotubes (CNTs) are poorly dispersed and easily agglomerated by π-π stacking in general solvents, whereas ILs can effectively shield them from π-π stacking, resulting in a favorable and steady dispersion. Thus, the cellulose composites of graphene/CNTs can be prepared with the assistance of ILs. In this paper, the solubilization of cellulose by ILs and the solubilization mechanism to the preparation of cellulose composites with graphene/CNTs are reviewed, the interactions between graphene, CNTs and cellulose in the composites are elucidated, and the preparation of cellulose composites with graphene/CNTs is introduced in terms of their structure, properties and application potential.

9.
Adv Mater ; : e2407274, 2024 Jul 18.
Artículo en Inglés | MEDLINE | ID: mdl-39030858

RESUMEN

Carbon materials have great potential for applications in energy, biology, and environment due to their excellent chemical and physical properties. Their preparation by carbonization methods encounters limitations and the carbon loss during pyrolysis in the form of gaseous molecules results in low yield of carbon materials. Herein a low-energy (600 °C) and high-yield (82 wt.%) carbonization strategy is developed using liquid gallium-assisted pyrolysis of metal-organic frameworks (MOFs) affording the N-doped carbon nanotube (CNT) non-hollow frameworks encapsulating Co nanoparticles. The liquid gallium layer offers protection against air, promotes heat transfer, and limits the escape of small carbonaceous gaseous molecules, which greatly improve the yields of the pyrolysis reaction. Experimental and theoretical results reveal that the synergistic interaction between CNTs and N/O-containing groups gives a non-hollow framework composed of N/O-enriched and open CNTs (NOCNTF-15, 15 denotes the 15 mm thickness of the liquid gallium layer during the pyrolysis) with high specific capacity (185 mAh g-1 at 10 A g-1) and ultra-stable cyclability (stable operation at 10 A g-1 and 50 °C for 20 000 cycles). This study provides a unique approach to carbonization that facilitates the practical application of low-cost CNTs and other MOFs-derived carbon materials in high-performance sodium-ion batteries (SIBs).

10.
Materials (Basel) ; 17(14)2024 Jul 11.
Artículo en Inglés | MEDLINE | ID: mdl-39063724

RESUMEN

Composite plates comprising a blend of rare earth neodymium-(Nd) doped M-type barium ferrite (BaM) with CNTs (carbon nanotubes) and polyethylene WERE synthesized through a self-propagating reaction and hot-pressing treatment. The plates' microscopic characteristics were analyzed utilizing X-ray diffraction (XRD), Fourier transform infrared spectrophotometry (FTIR), thermo-gravimetric analysis (TGA), Raman, and scanning electron microscopy (SEM) analytical techniques. Their microwave absorption performance within the frequency range of 8.2 to 18 GHz was assessed using a vector network analyzer. It showed that CNTs formed a conductive network on the surface of the Nd-BaM absorber, significantly enhancing absorption performance and widening the absorption bandwidth. Furthermore, dielectric polarization relaxation was investigated using the Debye theory, analyzing the Cole-Cole semicircle. It was observed that the sample exhibiting the best absorbing performance displayed the most semicircles, indicating that the dielectric polarization relaxation phenomenon can increase the dielectric relaxation loss of the sample. These findings provide valuable data support for the lightweight preparation of BaM-based absorbing materials.

11.
Materials (Basel) ; 17(12)2024 Jun 11.
Artículo en Inglés | MEDLINE | ID: mdl-38930222

RESUMEN

This study delved into the integration of carbon nanotubes (CNTs) in Ultra-High Performance Concrete (UHPC), exploring aspects such as mechanical properties, microstructure analysis, accelerated chloride penetration, and life service prediction. A dispersed CNT solution (0.025 to 0.075 wt%) was employed, along with a superplasticizer, to ensure high flowability in the UHPC slurry. In addition, the combination of high-strength functional artificial lightweight aggregate (ALA) and micro hollow spheres (MHS) was utilized as a replacement for fine aggregate to not only reduce the weight of the concrete but also to increase its mechanical performance. Experimental findings unveiled that an increased concentration of CNT in CNT1 (0.025%) and CNT2 (0.05%) blends led to a marginal improvement in compressive strength compared to the control mix. Conversely, the CNT3 (0.075%) mixture exhibited a reduction in compressive strength with a rising CNT content as an admixture. SEM analysis depicted that the heightened concentration of CNTs as an admixture induced the formation of nanoscale bridges within the concrete matrix. Ponding test results indicated that, for all samples, the effective chloride transport coefficient remained below the standard limitation of 1.00 × 10-12 m2/s, signifying acceptable performance in the ponding test for all samples. The life service prediction outcomes affirmed that, across various environmental scenarios, CNT1 and CNT2 mixtures consistently demonstrated superior performance compared to all other mixtures.

12.
ACS Appl Mater Interfaces ; 16(23): 30421-30429, 2024 Jun 12.
Artículo en Inglés | MEDLINE | ID: mdl-38832560

RESUMEN

Electrochromic devices (ECDs), which are capable of modulating optical properties in the visible and long-wave infrared (LWIR) spectra under applied voltage, are of great significance for military camouflage. However, there are a few materials that can modulate dual frequency bands. In addition, the complex and specialized structural design of dual-band ECDs poses significant challenges. Here, we propose a novel approach for a bendable ECD capable of modulating LWIR radiation and displaying multiple colors. Notably, it eliminates the need for a porous electrode or a grid electrode, thereby improving both the response speed and fabrication feasibility. The device employs multiwalled carbon nanotubes (MWCNTs) as both the transparent electrode and the LWIR modulator, polyaniline (PANI) as the electrochromic layer, and ionic liquids (HMIM[TFSI]) as the electrolyte. The ECD is able to reduce its infrared emissivity (Δε = 0.23) in a short time (resulting in a drop in infrared temperature from 50 to 44 °C) within a mere duration of 0.78 ± 0.07 s while changing its color from green to yellow within 3 s when a positive voltage of 4 V is applied. In addition, it exhibits excellent flexibility, even under bending conditions. This simplified structure provides opportunities for applications such as wearable adaptive camouflage and multispectral displays.

13.
J Environ Manage ; 362: 121349, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38833929

RESUMEN

The use of Ni-based catalysts is a common method for eliminating tar through catalytic cracking. Carbon deposition is the main cause of deactivation in Ni/ZSM-5 catalysts, with filamentous MWCNTs being the primary form of carbon deposits. This study investigates the formation and evolution of CNTs during the catalytic process of biomass tar to explore the mechanism behind carbon deposition. The effect of the 9Ni/10MWCNTs/81ZSM-5 on toluene reforming was investigated through a vertical furnace. Gases produced by tar catalysis were evaluated through GC analysis. The physicochemical structure, properties and catalytic performance of the catalyst were also tested. TG analysis was used to assess the accumulation and oxidation reactivity of carbon on the catalyst surface. An analysis was conducted on the mechanism of carbon deposition during catalyst deactivation in tar catalysis. The results showed that the 9Ni/91ZSM-5 had a superior toluene conversion of 60.49%, but also experienced rapid and substantial carbon deposition up to 52.69%. Carbon is mainly deposited as curved filaments on both the surface and pore channels of the catalyst. In some cases, tip growth occurs where both carbon deposition and Ni coexist. Furthermore, specific surface area and micropore volume are reduced to varying degrees due to carbon deposition. With the time increased, the amount of carbon deposited on the catalyst surface increased to 62.81%, which gradually approached saturation, and the overall performance of the catalyst was stabilized. This situation causes toluene molecules to detach from the active sites within the catalyst, hindering gas release, which leads to reduced catalytic activity and further carbon deposition. It provides both a basis for the development of new catalysts and an economically feasible solution for practical tar reduction and removal.


Asunto(s)
Nanotubos de Carbono , Níquel , Catálisis , Nanotubos de Carbono/química , Níquel/química , Breas/química , Carbono/química , Tolueno/química , Oxidación-Reducción
14.
Colloids Surf B Biointerfaces ; 241: 114032, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-38905812

RESUMEN

Carbon nanomaterials are indispensable due to their unique properties of high electrical conductivity, mechanical strength and thermal stability, which makes them important nanomaterials in biomedical applications and waste management. Limitations of conventional nanomaterials, such as limited surface area, difficulty in fine tuning electrical or thermal properties and poor dispersibility, calls for the development of advanced nanomaterials to overcome such limitations. Commonly, carbon nanomaterials were synthesized by chemical vapor deposition (CVD), laser ablation or arc discharge methods. The advancement in these techniques yielded monodispersed carbon nanotubes (CNTs) and allows p-type and n-type doping to enhance its electrical and catalytic activities. The functionalized CNTs showed exceptional mechanical, electrical and thermal conductivity (3500-5000 W/mK) properties. On the other hand, carbon quantum dots (CQDs) exhibit strong photoluminescence properties with high quantum yield. Carbon nanohorns are another fascinating type of nanomaterial that exhibit a unique structure with high surface area and excellent adsorption properties. These carbon nanomaterials could improve waste management by adsorbing pollutants from water and soil, enabling precise environmental monitoring, while enhancing wastewater treatment and drug delivery systems. Herein, we have discussed the potentials of all these carbon nanomaterials in the context of innovative waste management solutions, fostering cleaner environments and healthier ecosystems for diverse biomedical applications such as biosensing, drug delivery, and environmental monitoring.


Asunto(s)
Carbono , Sistemas de Liberación de Medicamentos , Nanoestructuras , Carbono/química , Humanos , Nanoestructuras/química , Nanotubos de Carbono/química , Puntos Cuánticos/química , Animales
15.
Chem Biodivers ; 21(7): e202301288, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38697942

RESUMEN

Recent breakthroughs in the field of carbon nanotubes (CNTs) have opened up unprecedented opportunities for the development of specialized bioactive CNT-polymers for a variety of biosensor applications. The incorporation of bioactive materials, including DNA, aptamers and antibodies, into CNTs to produce composites of bioactive CNTs has attracted considerable attention. In addition, polymers are essential for the development of biosensors as they provide biocompatible conditions and are the ideal matrix for the immobilization of proteins. The numerous applications of bioactive compounds combined with the excellent chemical and physical properties of CNTs have led to the development of bioactive CNT-polymer composites. This article provides a comprehensive overview of CNT-polymer composites and new approaches to encapsulate bioactive compounds and polymers in CNTs. Finally, biosensor applications of bioactive CNT-polymer for the detection of glucose, H2O2 and cholesterol were investigated. The surface of CNT-polymer facilitates the immobilization of bioactive molecules such as DNA, enzymes or antibodies, which in turn enables the construction of state-of-the-art, future-oriented biosensors.


Asunto(s)
Técnicas Biosensibles , Nanotubos de Carbono , Polímeros , Nanotubos de Carbono/química , Polímeros/química , Peróxido de Hidrógeno/análisis , Peróxido de Hidrógeno/química , Glucosa/análisis , Colesterol/análisis , Colesterol/química , Humanos
16.
J Colloid Interface Sci ; 670: 337-347, 2024 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-38763029

RESUMEN

Electroactive coatings for smart wearable textiles based on a furan bio-epoxy monomer (BOMF) crosslinked with isophorone diamine (IPD) and additivated with carbon nanotubes (CNTs) are reported herein. The effect of BOMF/IPD molar ratio on the curing reaction, as well as on the properties of the crosslinked resins was first assessed, and it was found that 1.5:1 BOMF/IPD molar ratio provided higher heat of reaction, glass transition temperature, and mechanical performance. The resin was then modified with CNT to prepare electrically conductive nanocomposite films, which exhibited conductivity values increased by eight orders of magnitude upon addition of 5 phr of CNTs. The epoxy/CNT nanocomposites were finally applied as coatings onto a cotton fabric to develop electrically conductive, hydrophobic and breathable textiles. Notably, the integration of CNTs imparted efficient and reversible electrothermal behavior to the cotton fabric, showcasing its potential application in smart and comfortable wearable electronic devices.

17.
ACS Nano ; 18(23): 15035-15045, 2024 Jun 11.
Artículo en Inglés | MEDLINE | ID: mdl-38796777

RESUMEN

Two-electron oxygen reduction reaction (2e- ORR) is of great significance to H2O2 production and reversible nonalkaline Zn-air batteries (ZABs). Multiple oxygen-containing sp2-bonded nanocarbons have been developed as electrocatalysts for 2e- ORR, but they still suffer from poor activity and stability due to the limited and mixed active sites at the edges as well as hydrophilic character. Herein, graphdiyne (GDY) with rich sp-C bonds is studied for enhanced 2e- ORR. First, computational studies show that GDY has a favorable formation energy for producing five-membered epoxy ring-dominated groups, which is selective toward the 2e- ORR pathway. Then based on the difference in chemical activity of sp-C bonds in GDY and sp2-C bonds in CNTs, we experimentally achieved conductive and hydrophobic carbon nanotubes (CNTs) covering O-modified GDY (CNTs/GDY-O) through a mild oxidation treatment combined with an in situ CNTs growth approach. Consequently, the CNTs/GDY-O exhibits an average Faraday efficiency of 91.8% toward H2O2 production and record stability over 330 h in neutral media. As a cathode electrocatalyst, it greatly extends the lifetime of 2e- nonalkaline ZABs at both room and subzero temperatures.

18.
Discov Nano ; 19(1): 74, 2024 Apr 30.
Artículo en Inglés | MEDLINE | ID: mdl-38689025

RESUMEN

Carbon nanotube (CNT) has fostered research as a promising nanomaterial for a variety of applications due to its exceptional mechanical, optical, and electrical characteristics. The present article proposes a novel and comprehensive micromechanical framework to assess the viscoelastic properties of a multiscale CNT-reinforced two-dimensional (2D) woven hybrid composite. It also focuses on demonstrating the utilisation of the proposed micromechanics in the dynamic analysis of shell structure. First, the detailed constructional attributes of the proposed trans-scale composite material system are described in detail. Then, according to the nature of the constructional feature, mathematical modelling of each constituent phase or building block's material properties is established to evaluate the homogenised viscoelastic properties of the proposed composite material system. To highlight the novelty of this study, the viscoelastic characteristics of the modified matrix are developed using the micromechanics method of Mori-Tanaka (MT) in combination with the weak viscoelastic interphase (WI) theory. In the entire micromechanical framework, the CNTs are considered to be randomly oriented. The strength of the material (SOM) approach is used to establish mathematical frameworks for the viscoelastic characteristics of yarns, whereas the unit cell method (UCM) is used to determine the viscoelastic properties of the representative unit cell (RUC). Different numerical results have been obtained by varying the CNT composition, interface conditions, agglomeration, carbon fibre volume percentage, excitation frequency, and temperature. The influences of geometrical parameters like yarn thickness, width, and the gap length to yarn width ratio on the viscoelasticity of such composite material systems are also explored. The current study also addresses the issue of resultant anisotropic viscoelastic properties due to the use of dissimilar yarn thickness. The results of this micromechanical analysis provide valuable insights into the viscoelastic properties of the proposed composite material system and suggest its potential applications in vibration damping. To demonstrate the application of developed novel micromechanics in vibration analysis, as one of the main contributions, comprehensive numerical experiments are conducted on a shell panel. The results show a significant reduction in vibration amplitudes compared to traditional composite materials in the frequency response and transient response analyses. To focus on the aspect of micromechanical behaviour on dynamic response and for the purpose of brevity, only linear strain displacement relationships are considered for dynamic analysis. These insights could inform future research and development in the field of composite materials.

19.
ACS Appl Mater Interfaces ; 16(17): 21746-21756, 2024 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-38631911

RESUMEN

Considering the importance of physics and chemistry at material interfaces, we have explored the coupling of multinary chalcogenide semiconductor Cu2NiSnS4 nanoparticles (CNTS NPs) for the first time with the noble metal (Au) to form Au-CNTS nano-heterostructures (NHSs). The Au-CNTS NHSs is synthesized by a simple facile hot injection method. Synergistic experimental and theoretical approaches are employed to characterize the structural, optical, and electrical properties of the Au-CNTS NHSs. The absorption spectra demonstrate enhanced and broadened optical absorption in the ultraviolet-visible-near-infrared (UV-Vis-NIR) region, which is corroborated by cyclic voltammetry (CV) readings. CV measurements show type II staggered band alignment, with a conduction band offset (CBO) of 0.21 and 0.23 eV at the Au-CNTS/CdS and CNTS/CdS interface, respectively. Complementary first-principles density functional theory (DFT) calculations predict the formation of a stable Au-CNTS NHSs, with the Au nanoparticle transferring its electrons to the CNTS. Moreover, our interface analysis using ultrafast transient absorption experiments demonstrate that the Au-CNTS NHSs facilitates efficient transport and separation of photoexcited charge carriers when compared to pristine CNTS. The transient measurements further reveal a plasmonic electronic transfer from the Au nanoparticle to CNTS. Our advanced analysis and findings will prompt investigations into new functional materials and their photo/electrocatalysis and optoelectronic device applications in the future.

20.
Small ; 20(30): e2311657, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38461547

RESUMEN

A complex electromagnetic environment is a formidable challenge in national defense areas. Microwave-absorbing materials are considered as a strategy to tackle this challenge. In this work, lightweight, flexible, and thermal insulating Carbon/SiO2@CNTs (CSC) aerogel is successfully prepared coupled with outstanding microwave absorbing performance, through freeze-drying and high-temperature annealing techniques. The CSC aerogel shows a strong reflection loss (-55.16 dB) as well as wide effective absorbing bandwidth (8.5 GHz) in 2-18 GHz. It also retains good microwave absorption properties under tension and compression. Radar cross-sectional (RCS) simulation result demonstrates the CSC processing a strong reduction ability of RCS compared with a metal plate. Further exploration shows amazing flexibility and good thermal insulation properties of CSC. The successful preparation of this composite aerogel provides a broad prospect for the design of microwave-absorbing materials.

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