Silicon Carbide Nanoparticles Research Articles

Molten salt electrosynthesis of silicon carbide nanoparticles and their photoluminescence property

A one-step molten salt electrochemical strategy was proposed to synthesize SiC nanoparticles from ultra-fine silicon dioxide/carbon (SiO2/C) mixtures. The electrosynthesis process and physicochemical properties of the synthesized products were systematically analyzed via X-ray diffraction, electron microscopy, Raman spectroscopy and photoluminescence spectroscopy, etc. A combined chemical/electrochemical reaction, electrochemical deoxidation, and in-situ carbonization reaction mechanism was proposed to reveal the electrochemical synthesis process of SiC nanoparticles from SiO2/C in molten CaCl2. The as-prepared SiC with particle size ranging from 8 to 14 nm possesses a polycrystalline structure. In addition, the SiC nanoparticles demonstrate obvious photoluminescence property due to the synergetic size effect and microstructural characteristics.

Preparation and study the behavior of blend (Ep+ PMAA) reinforced by SiC and B nanopartieles

Composite materials (A, A1, A2, A3) were prepared from blend (Ep95%+PMAA 5%) reinforced by silicon carbide (SiC) of a grain size less than ( 80 nm ) and boron ( B ) of grain size ( 70 nm ) with weight fraction of 20% , using the hand layup method. Composites materials of which have been prepared are: * Blend of ( Ep 95% + PMAA 5% ) is symbol A.* Blend ( Ep + PMAA ) 80% +SiC 10% +B 10% with weight fraction of 20% is symbol A1.* Blend ( Ep + PMAA ) 80%+ B 20% with weight fraction of 20% is symbol A2.** Blend ( Ep + PMAA) 80% + SiC 20% with weight fraction of 20% is symbol A3. Study involved some mechanical tests, such as Tensile, bending (3-point test), compression and hardness tests. Also some physical test, thermal conductivity and electrical conductivity (dielectric constant).as well as the effect of the environment on the behavior of the composites. The result shows that the addition of SiC and boron nanoparticles powder to the blend (Epoxy + PMAA) enchained the mechanical properties for sample A1 A2 A3 at normal condition. By comparison it was found.

Enhanced switching electric field and breakdown strength of epoxy composites with core‐shell silicon carbide nanoparticles

AbstractSilicon carbide (SiC) is widely used to improve the non‐linear conductivity of non‐linear resistive field grading composite. In this paper, the SiC nanoparticles are modified into core‐shell nanoparticles with silica (SiO2) coating on the surface and are characterised by transmission electron microscopy and X‐ray diffraction, respectively. The 7 wt% SiC@SiO2/epoxy nanocomposite is then prepared, and the pure epoxy and 7 wt% SiC/epoxy nanocomposite are prepared as a contrast. The relative permittivity, thermally stimulated current, conductivity and breakdown strength are studied, respectively. The presence of SiO2 shell around SiC nanoparticles has a great effect on the relative permittivity and trap distribution. The epoxy nanocomposites show non‐linear conductivity characteristics, compared with pure epoxy. The 7 wt% SiC@SiO2/epoxy nanocomposite has higher switching electric field and breakdown strength than the 7 wt% SiC/epoxy nanocomposite, which is helpful for the application of non‐linear resistive field grading composite in higher‐voltage equipment or components.

Silicon Carbide Nanoparticles as a Mechanical Boosting Agent in Material Extrusion 3D-Printed Polycarbonate.

In this work, the effect of silicon carbide (carborundum, SiC), as a boosting agent of the mechanical response of the polycarbonate (PC) polymer, was investigated. The work aimed to fabricate nanocomposites with an improved mechanical performance and to further expand the utilization of 3D printing in fields requiring an enhanced material response. The nanocomposites were produced by a thermomechanical process in various SiC concentrations in order to evaluate the filler loading in the mechanical enhancement. The samples were 3D printed with the material extrusion (MEX) method. Their mechanical performance was characterized, following international standards, by using dynamic mechanical analysis (DMA) and tensile, flexural, and Charpy’s impact tests. The microhardness of the samples was also measured. The morphological characteristics were examined, and Raman spectra revealed their structure. It was found that SiC can improve the mechanical performance of the PC thermoplastic. A 19.5% increase in the tensile strength was found for the 2 wt.% loading nanocomposite, while the 3 wt.% nanocomposite showed a 16% increase in the flexural strength and a 35.9% higher impact strength when compared to the unfilled PC. No processability issues were faced for the filler loadings that have been studied here.

Impact of AlN-SiC Nanoparticle Reinforcement on the Mechanical Behavior of Al 6061-Based Hybrid Composite Developed by the Stir Casting Route

The enhancement of composites’ mechanical characteristics (tensile, compressive, and hardness) is a constant demand for technological advancement. The stir casting process is used to make the hybrid aluminium alloy metal matrix composites Al 6061-SiC-AlN in our present study. To create mechanical qualities such as tensile, compressive, and hardness, silicon carbide and aluminium nitride (both 3% and 6%) were utilized as the reinforcement. The tensile strength, compressive strength, and hardness of the Al 6061-SiC-AlN hybrid composites samples were determined. The tensile, compressive, and hardness parameters of Al 6061-SiC-AlN hybrid composites are estimated and evaluated to those of the matrix Al 6061 alloy. With the inclusion of silicon carbide and AlN nanoparticles, the tensile strength, compressive strength, and hardness increased from 328 to 385 MPa, 145 to 178 Mpa, and 302 to 724 VHN, respectively.

Fabrication of 4H–SiC nanoparticles using femtosecond pulsed laser ablation in deionized water

In this paper, the silicon carbide (SiC) nanoparticle colloidal solution is obtained by using the femtosecond (fs) laser ablation in deionized water. The spherical nanoparticles are uniform in size with an average diameter of 2.84 nm analyzed by transmission electron microscope (TEM). X-ray diffraction patterns (XRD) show that the crystal structure of the nanoparticles is still 4H–SiC. Absorption spectrum shows strong absorption of SiC colloidal solution in ultraviolet region. The optical nonlinearity of SiC nanoparticles colloidal solution is investigated by the Z scan experiment, it is found that the SiC nanoparticles have reverse saturation absorption characteristics. The nonlinear absorption coefficient β is measured to be about 3 × 10−13 m/W.

SO2 sensing mechanism of nanostructured SiC-SiOxC core shell: An operando DRIFT investigation

The possible use of nanostructured silicon carbide for the manufacturing of chemiresistive gas sensors with high selectivity towards sulfur dioxide has been recently explored. In this work, we take this topic a step further with an in-depth investigation on the role played by the oxidation process occurring on the surface of silicon carbide nanoparticles during the detection of SO2. This study starts by understanding the oxidation process at different temperatures and subsequently investigates the reaction mechanism of SO2, in both dry and wet atmosphere, at the optimal working temperature for the sensor operation. The device was characterized using a diffuse reflectance infrared Fourier transform spectroscopy setup capable of working in operando conditions with a dedicated electronics for the simultaneous monitoring of surface chemical reactions on the sensing film together with its electrical activity. This work demonstrates that the oxidation of silicon carbide nanoparticles is at the core of the modification of the overall electrical characteristics of the device. It was also proved that the exposure to SO2 increases the oxidation rate of the silicon carbide film in working conditions. Moreover, it was observed that this behavior is magnified by the presence of humidity.Finally, a proposed sensing mechanism is suggested highlighting a mainly ionic electrical conduction, in which working conditions play a fundamental role in affecting the concentration and mobility of charge carriers.

Fabrication of luminescent silicon carbide nanoparticles by pulsed laser synthesis in liquid

Fabrication of luminescent silicon carbide nanoparticles by pulsed laser synthesis in liquid

Enhancement of thermal properties of Kevlar 29 coated by SiC and TiO2 nanoparticles and their binding energy analysis

In the fields of military research, aerospace, and vehicle technology, the thermal stability of Kevlar fiber is critical for improving its flame resistance. In this work, the pad mangle machine was used to improve the thermal properties of Kevlar 29 in order to expand the range of applications for thermal aspects. Silicon carbide and titanium oxide nanoparticles provide thermal stability on the fiber surface through intermolecular adhesion. Here, 5 wt% and 10 wt% of nanoparticles with various mass ratios (1:1) have been chosen. Thermogravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC) analysis, and X-ray Photoelectron Spectroscopy (XPS) analysis have all been used to measure different thermal properties. The surface morphology of samples is represented by FESEM analysis, while the active organic groups are represented by FTIR analysis. The greater crystallization of epoxy and nanoparticles is linked to post-heat treatment of the material. The glass transition temperature of the coated samples shifted maximum from 559.13 °C to 580.51 °C, the end set temperature increased by 30.67 °C compared to the uncoated sample, and the residual weight changed from 29.77 percent to 4.06 percent, according to the findings (i.e., lightweight). When compared to the uncoated sample, the coated sample's enthalpy increased significantly (i.e., the samples can absorb more heat). The smaller the positive binding energy, the higher the activation energy, and hence the slower the chemical reaction, which is especially important in high-temperature applications. Finally, this research reveals a 4.5–5.2 percent increase in thermal characteristics.

Effect of stacking sequence and silicon carbide nanoparticles on properties of carbon/glass/Kevlar fiber reinforced hybrid polymer composites

AbstractSynthetic fibers as reinforcement in composites are inevitable in today's composite industry due to its exceptional mechanical properties. The objective of this paper is to investigate the effect of stacking sequence of carbon, glass and Kevlar bidirectional (0°/90°) woven mat synthetic fibers reinforced in epoxy matrix composite with silicon carbide (SiC) nanoparticles as filler material on mechanical and visco‐elastic behavior of developed novel hybrid polymer matrix composites (HPMCs). Vacuum bag infusion method is adopted to manufacture the composite specimens by stacking carbon, glass and Kevlar fibers alternatively with six layers and six different stacking sequences and tested as per ASTM standards. Tensile, flexural, impact and hardness test is conducted to identify the composite specimen with maximum mechanical characteristics. The maximum tensile and flexural strength of 398.178 and 671.25 MPa respectively is seen for the composite with strong fibers such as carbon and glass stacked away from the neutral axis. Also, the scanning electron microscope (SEM) images of tensile and flexural failure specimen revealed the failure mechanisms of developed composite specimens. Moreover, the dynamic mechanical analysis (DMA) revealed the visco‐elastic behavior of developed composites with glass transition temperature (Tg) at 115°C. This study emphasizes the influence of stacking sequence on thermo‐mechanical properties of the developed HPMC specimens and explores its potential for diverse applications.

Synchronously improved thermal conductivity and dielectric constant for epoxy composites by introducing functionalized silicon carbide nanoparticles and boron nitride microspheres

Polymer-based dielectrics with high thermal conductivity and superb dielectric properties hold great promising for advanced electronic packaging and thermal management application. However, integrating these properties into a single material remains challenging due to their mutually exclusive physical connotations. Here, an ideal dielectric thermally conductive epoxy composite is successfully prepared by incorporating multiscale hybrid fillers of boron nitride microsphere (BNMS) and silicon dioxide coated silicon carbide nanoparticles (SiC@SiO2). In the resultant composites, the microscale BNMS serve as the principal building blocks to establish the thermally conductive network, while the nanoscale SiC@SiO2 as bridges to optimize the heat transfer and suppress the interfacial phonon scattering. In addition, the special core–shell nanoarchitecture of SiC@SiO2 can significantly impede the leakage current and generate a great deal of minicapacitors in the composites. Consequently, favorable thermal conductivity (0.76 W/mK) and dielectric constant (∼8.19) are simultaneously achieved in the BNMS/SiC@SiO2/Epoxy composites without compromising the dielectric loss (∼0.022). The strategy described in this study provides important insights into the design of high-performance dielectric composites by capitalizing on the merits of different particles.

Enhanced thermoelectric ZT in the tails of the Fermi distribution via electron filtering by nanoinclusions: Model electron transport in nanocomposites

Silicon carbide nanoparticles with diameters around 8 nm and narrow size distribution have been finely mixed with doped silicon nanopowders and sintered into bulk samples to investigate the influence of nanoinclusions on electrical and thermal transport properties. We have compared the thermoelectric properties of samples ranging from 0%--5% volume fraction of silicon carbide. The silicon carbide nanoinclusions lead to a significant improvement in the thermoelectric figure of merit ZT largely due to an enhancement of the Seebeck coefficient. A semiclassical Boltzmann transport equation is used to model the electrical transport properties of the Seebeck coefficient and electrical conductivity. The theoretical analysis confirms that the enhancements in the thermoelectric properties are consistent with the energy selective scattering of electrons induced by the offset between the silicon Fermi level and the carbide conduction band edge. This study proves that careful engineering of the energy-dependent electron scattering rate can provide a route towards relaxing long-standing constraints in the design of thermoelectric materials.

Simultaneous engineering on absorption window and transportation geometry of graphene-based foams toward high-performance solar steam generator

Graphene-based materials are frequently highlighted as the candidate for solar steam generation (SSG) because of their advantages such as high solar absorption, tunable structure and low cost. However, graphene itself is not a “perfect” absorber for full solar spectrum and cannot efficiently transport water on its surface due to its intrinsic physicochemical characteristics. Here we designed and synthesized a graphene foam in a three-dimensional (3D) interconnected porous structure with silicon carbide nanoparticles anchored on graphene surfaces. The systematical characterizations confirm that the hybrid structure extends the solar absorption window of graphene in full solar spectrum; and moreover, the in situ environmental scanning electron microscopy (ESEM) experiments suggest the incorporation of SiC nanoparticles on two-dimensional graphene surface improves the condensation and transportation kinetics of water in the foam. As a result, the SSG device based on the graphene-SiC composite demonstrates an improved energy conversion efficiency up to 95% under one sun illumination compared with those of previous reported graphene-based materials. The findings may shed new light on the technologies for solar-energy-water nexus.

Solidification of a nano-enhanced phase change material (NePCM) in a double elliptical latent heat storage unit with wavy inner tubes

This work investigates an optimal model of the heat recovery from a double elliptical latent heat storage system using wavy inner tubes and nano-enhanced phase change material (PCM). A discharging rate and time, as well as the PCM thermal distribution in a three-dimensional simulation, are evaluated considering various alignments for both inner and outer ellipse pipes. The use of two inner tubes in two different cases considering straight and wavy tubes is also examined, followed by influences of various concentrations and types of nanoparticles. The inlet temperature and Reynolds number of heat transfer fluid (HTF) are also examined. ANSYS-FLUENT software is used to perform the numerical simulation. RT 35 and Silicon Carbide (SiC) are employed as the PCM and nanomaterials, respectively. Water is also considered as the HTF with the Reynolds number of 900. Different values of 20 and 40 mm are proposed for the horizontal and vertical radii of the outer tube to examine the different orientations of the elliptical tube considering the inner radius ranged from 4.95 to 14 mm. The findings show that the vertical alignment of the inner tube compound in the centre of the horizontal position of the outer tube presents higher efficiency during the solidification process. Using double pipes in both straight and wavy configurations increases the surface area, which enhances the heat transfer rate, accelerating the solidification rate by 1.26 and 1.1, respectively. The PCM compound with SiC nanoparticles with 2% and 4% concentrations accelerates the discharging rate by 2.8 and 4.8 times, respectively, compared with the single straight inner pipe case. Furthermore, it is found that by decreasing the temperature of the heat transfer fluid from 285 K to 280 K, the total solidification time reduces from 48 to 39 min.

Evaluation of Silicon Carbide Nanoparticles as an Additive to Minimize Surfactant Loss during Chemical Flooding

AbstractSurfactant flooding is a prolific enhanced oil recovery technique. It alters the rock fluid interfacial interactions between reservoir fluids and rocks. However, a pair of impeding factors often limit the economic viability of the process and need to be optimized. The first is the surfactant loss on the adsorbent surface due to adsorption making it a potential environmental problem. The second is the Critical Micelle Concentration (CMC) which governs the amount of surfactant pumped. This study aimed to minimize the surfactant loss and the CMC, thereby optimizing the flooding efficiency and reducing the environmental concerns for nanoparticle applications. To achieve this, Silicon Carbide nanoparticles (SCN) were employed as additives to the surfactant solution. It was observed that the use of SCN reduces the surfactant adsorption by as much as 44 % and the critical micelle concentration by 14 %. The studies also observed that the concentration of SCN required to get these results is dramatically (more than 25 times) lower than previously reported literature on other nanoparticles. To adsorption isotherm studies provide an insight into the type of adsorption taking place. The adsorption isotherm follows the Langmuir model.

Bi2WO6/SiC composite photocatalysts with enhanced photocatalytic performance for dyes degradation

Bi2WO6 demonstrates the limited photocatalytic activity due to its high photoelectron recombination rate. However, its photocatalytic performance is expected to be improved by forming Step-scheme (S-scheme) heterojunction and SiC is a potential candidate because of its high electron transfer rate in photocatalytic process. In this study, S-scheme heterojunction Bi2WO6/SiC nanocomposites were synthesized by simple hydrothermal method, and their photo degradation properties for rhodamine B (RhB) under visible light were studied. The results show that silicon carbide nanoparticles have been successfully deposited onto the petal-microsphere shaped Bi2WO6 phase. The nanocomposite with mole ratio of Bi2WO6 to SiC of 1:1 exhibits the highest photo degradation rate as tested in the photocatalytic experiments. The photoreaction rate of the nanocomposite is 3.7 times higher than that of pure Bi2WO6 and 15.5 times higher than that of pure SiC, and the nanocomposite demonstrates good photocatalytic stability.

Synthesis and Properties of Silicon Carbide Nanoparticles Obtained by the Laser Pyrolysis of a Mixture of Monosilane and Acetylene

Synthesis and Properties of Silicon Carbide Nanoparticles Obtained by the Laser Pyrolysis of a Mixture of Monosilane and Acetylene

The structural, magnetic, and pinning features of Bi-2223 superconductors: Effects of SiC nanoparticles addition

In this research, the influence of Silicon Carbide nanoparticles (SiC-NPs) addition on the microstructure, superconducting, and pinning properties of (Bi, Pb)2Sr2Ca2Cu3O10+θ (Bi-2223) superconductors is comprehensively studied. The superconductors are synthesized by the sol-gel method and SiC-NPs are added up to 0.8 wt%. The X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM) measurements are carried out for structural and morphological investigations. The superconductivity parameters such as intra-granular critical current density (JC, intra), inter-granular current critical density (JC, inter), transport critical current density (JC, t), and pinning force density (FP) are detected through DC- and AC-susceptibility, hysteresis loop, and transport measurements. The obtained results show that the 0.4 wt% addition of SiC-NPs improves the microstructure and the connectivity of grains as well as JC, inter, JC, intra, JC, t, and FP in the Bi-2223 superconductor. This research opens notable avenues for the use of synthesized Bi-2223 ceramics for electrical and industrial applications such as high-current energy storage, wires, and tapes.

Thermally stable carbon-coated SiC/polydimethylsiloxane nanocomposites for EMI shielding in the terahertz range

Rapid development of terahertz (THz) technologies makes electromagnetic interference (EMI) shielding increasingly critical for control of electromagnetic (EM) radiation and reduction of EM pollution. In this study, carbon-coated silicon carbide nanoparticles (SiC@C NPs) are synthesized by arc-discharge plasma and dispersed into a polydimethylsiloxane (PDMS) matrix to fabricate SiC@C/PDMS nanocomposites (SiC@C/PDMS NCs). The NCs demonstrate excellent THz shielding/absorption performances in virtue of the SiC@C NP fillers and composite structure in a wide range from 0.5 to 3.0 THz. The maximum shielding efficiency and reflection loss in the range from 0.5 to 3.0 THz reach up to 44.5 and 19.0 dB on average, respectively, for the NC with a loading of 10 wt.% SiC@C NPs and 0.6 mm thickness. The SiC@C/PDMS NCs possess a high thermal stability in air, as well as lightweight and hydrophobicity. This work would provide an insight into the functionalization of the SiC@C NPs as high-performance THz shielding materials.

Relating detonation parameters to the detonation synthesis of silicon carbide

Detonation synthesis of silicon carbide (SiC) nanoparticles from carbon liberated by negatively oxygen balanced explosives was evaluated in a 23 factorial design to determine the effects of three categorical experimental factors: (1) cyclotrimethylene-trinitramine (RDX)/2,4,6-trinitrotoluene (TNT) ratio, (2) silicon (Si) additive concentration, and (3) Si particle size. These factors were evaluated at low and high levels as they relate to the detonation performance of the explosive and the solid Si-containing phases produced. Detonation velocity and Chapman–Jouguet (C–J) detonation pressure, which were measured using rate stick plate dent tests, were evaluated. Solid detonation product mass, silicon carbide product concentration, and residual silicon concentration were evaluated using the x-ray diffraction analysis. The factors of Si concentration and the RDX:TNT ratio were shown to affect detonation performance in terms of detonation velocity and C–J pressure by up to 10% and 22%, respectively. Increased concentration of Si in the reactants improved the average SiC concentration in the detonation products from 1.9 to 2.8 wt. %. Similarly, increasing the ratio of RDX to TNT further oxidized detonation products and reduced the average residual Si remaining after detonation from 8.6 to 2.8 wt. %. A 70:30 mass ratio mixture of RDX to TNT loaded with 10 wt. % < 44 μm silicon powder produced an estimated 1.33 g of nanocrystalline cubic silicon carbide from a 150-g test charge. Using a lower concentration of added silicon with a finer particle size reduced SiC yield in the residue to 0.38 g yet improved the SiC to residual Si ratio to 1.64:1.