Influence Of Carbon Nanotubes Research Articles

Influence of carbon nanotubes on printing quality and mechanical properties of 3D printed cementitious materials

This paper presents the impact of incorporating carbon nanotubes (CNTs) into the 3D printing of cementitious materials, along with the effective dispersion of CNTs. Compared to the control mix, adding CNTs with superplasticizer significantly enhanced the printing quality by reducing the error in height of two-layers from 38% to 30% and an 81% enhancement in the buildability. Moreover, rheology properties revealed shear-thinning behaviour with lower viscosity, resulting in improved flowability. The progressive increase in CNT concentrations up to 0.2% yielded a noteworthy improvement in the mechanical properties. At 28 days, the incorporation of 0.2% CNTs resulted in a significant increase in the flexural strength, compressive strength, and Young's modulus by 99%, 72%, and 43%, respectively, compared to the mix containing silica fume. Microstructural investigation of the CNT-cement matrix revealed nanoscale crack bridges formed by CNTs, reinforcing the cementitious material and improving its mechanical properties.

Influence of carbon nanotubes on the morphology of Cu6Sn5 in Cu/(Sn–Ag–Cu) solder joints

This study delves into the intricate interaction between multi-walled carbon nanotubes (MWCNTs) and the Sn–Ag–Cu solder system, highlighting its relevance in lead-free soldering applications. Reflow and isothermal aging induce the formation of intermetallic layers at the joint interface, including Cu6Sn5, Cu3Sn, and irregularly shaped Ag3Sn particles. The addition of MWCNTs leads to the flattening of Cu6Sn5 grains, restraining their growth and potentially improving mechanical strength. Notably, MWCNTs exhibit a relatively high affinity with Ag3Sn. Grain size distribution analysis indicates that MWCNTs reduce particle size, effectively suppressing intermetallic compound growth. Over time, grain size increases due to simultaneous coarsening and growth during isothermal aging. In the growth kinetics analysis of intermetallic compounds in SAC305-MWCNTs solder joints, stable behavior is observed for Cu3Sn growth, driven by solid-state diffusion between Cu6Sn5 and Cu. In contrast, Cu6Sn5 exhibits significant variations in growth behavior with temperature changes. Furthermore, the evaluation of activation enthalpy for Cu3Sn growth in the Cu/(SAC305-MWCNTs) and Cu/SAC305 diffusion couples reveals similar n and k values of the power function for the layer growth, indicating a comparable rate-controlling process for Cu3Sn growth. The presence of MWCNTs in the solder does not significantly influence the rate-controlling process or activation enthalpy for Cu3Sn growth, contrasting with the observed effects on Cu6Sn5 growth. This study provides valuable insights into the interactions within the SAC305-MWCNTs solder system, offering significant implications for lead-free soldering applications.

A Systematic Investigation on the Effect of Carbon Nanotubes and Carbon Black on the Mechanical and Flame Retardancy Properties of Polyolefin Blends.

Due to high filler loading, clean, commercial, thermoplastic, flame-retardant materials are mechanically unstable when insulating wires and cables. In this study, composite formulations of linear low-density polyethylene (LLDPE)/ethylene-vinyl acetate (EVA) containing a flame retardant, such as magnesium hydroxide (MH; formula: Mg(OH)2) and huntite hydromagnesite (HH; formula: Mg3Ca(CO3)4, Mg5(CO3)4(OH)2·3H2O), were prepared. The influence of carbon nanotubes (CNTs) and carbon black (CB) on the mechanical properties and flame retardancy of LLDPE/EVA was studied. Three types of CNTs were examined for their compatibility with other materials in clean thermoplastic flame-retardant compositions. The CNTs had the following diameters: 10-15 nm, 40-60 nm, and 60-80 nm. Optimum mechanical flame retardancy and electrical properties were achieved by adding CNTs with an outer diameter of 40-60 nm and a length of fewer than 20 nm. Large-sized CNTs result in poor mechanical characteristics, while smaller-sized CNTs improve the mechanical properties of the composites. CB enhances flame retardancy but deteriorates mechanical properties, particularly elongation at break, in clean, black, thermoplastic, flame-retardant compositions. Obtaining satisfactory compositions that meet both properties, especially formulations passing the V-0 of the UL 94 test with a minimum tensile strength of 9.5 MPa and an elongation at break of 125%, is challenging. When LLDPE was partially substituted with EVA, the limiting oxygen index (LOI) increased. The amount of filler in the formulations determined how it affected flammability. This study also included a reliable method for producing clean, black, thermoplastic, flame-retardant insulating material for wire and cable without sacrificing mechanical properties.

Influence of CNTs on the gradient phase structure formed by the layered resin structure used to model the interlaminar region of interleaved FRPs

Abstract The interleaved fiber-reinforced polymer composites (FRPs) by carbon nanotubes (CNTs)/thermoplastic polyetherketone-cardo (PEK-C) hybrid interleaves show the potential of comprehensively improving the mechanical properties of composites and have been hotspot. However, the synergistic effect and mechanism of CNTs and TP resin have not been attained. The interlaminar region of interleaved composites is too narrow and complex to be fully analyzed. Therefore, the layered resin structure composed of an interlayer and a matrix (epoxy) layer was prepared to model the interlaminar region in this study. The evolution of gradient structure developed by the layered structure in curing and the influence of presence of CNTs in interlayer were investigated based on morphology characterization. The results showed that epoxy resin gradually diffused into the interlayer, resulting in the concentration gradient and the resultant gradient phase structure. The presence of CNTs in hybrid interlayer hindered the resin diffusion and consequently hindered the formation of dual-phase structure, which was not conducive to the toughness improvement. The inappropriate high temperature was not recommended due to the effect of facilitating diffusion, probably resulting in the formation of excrescent epoxy layer in the interlaminar region and undesired mechanical performance. This study conducted experiments on resin system to simplify the interesting subject and the results will help to develop the synergistic mechanism of TP resin and nanoparticles.

Carbon Nanotubes (CNT) as an additive towards crack-free catalyst coated membranes (CCM)

In this study, carbon nanotubes (CNT) were used as an additive in coating inks for catalyst layers for PEM electrolyzers and fuel cells. Catalyst layers with and without CNT were prepared by direct membrane coating and analyzed for cracking behavior. The influence of CNT on crack prevention is discussed by varying the film thickness. Layers with CNT show no or less cracks at the same film thickness. Increasing the drying rate by raising the film temperature has no effect on crack formation, which allows shorter production times. The distribution and interaction of CNT in the microporous system are also discussed.

Influence of Carbon Nanotubes on the Mechanical Properties of PLA/MWCNTS Printed Parts in FDM Process

This study systematically and comprehensively investigates the 3D printing process and mechanical properties of PLA/MWCNTS composite material using pneumatic extrusion. Mechanical test specimens were prepared utilizing a pneumatic extrusion 3D printing system, followed by conducting mechanical performance tests. The study focuses on assessing the influence of different material ratios on the strength of these specimens, employing a controlled variable method with varied printing paths. The results demonstrate a significant improvement in the mechanical properties of PLA printed specimens upon the addition of carbon nanotubes, indicating the promising potential of PLA/MWCNTS composite materials as functional materials for FDM technology.

Non-linear stability characteristics of randomly distributed CNT-reinforced fiber composite beams under thermo-mechanical loadings

The aim of the present study is to elucidate the non-linear stability characteristics of randomly distributed carbon nanotube-reinforced fiber composite (RD-CNTRFC) beams subjected to thermo-mechanical loading. Effective material properties of RD-CNTRFC are estimated using the Eshelby-Mori-Tanaka approach and Halpin–Tsai micromechanical techniques. The material properties are considered to be temperature-dependent, and the influence of carbon nanotube (CNT) agglomeration is also incorporated in material properties estimation of hybrid matrix. The strain-displacement relations are assumed by incorporating the higher-order shear deformation theory and geometrical nonlinearity (von Kármán). The governing partial differential equations are obtained by minimizing the total potential energy of the beam. Buckling loads of beam subjected to in-plane compressive loads are estimated using Eigen value approach. Similarly, buckling temperatures are also determined by solving Eigenvalue problem iteratively due to temperature-dependent material properties. The non-linear equilibrium paths under thermal and mechanical loadings are traced through iterative Eigenvalue approach. Numerical results are presented to elucidate the influence of various parameters like CNT agglomeration, ply sequences, span-to-depth ratio, boundary conditions, and mass fraction of CNTs.

Influence of carbon nanotubes on the formation of shock electromagnetic waves

Based on the shortened Maxwell equations, for a nonlinear medium containing carbon nanotube of the semiconductor type, the formation of shock waves is studied. A classical nonlinear medium with cubic nonlinearity and dispersion is considered. It has been established that the introduction of carbon nanotubes stabilizes an ultrashort optical pulse and prevents the formation of shock waves. However, the pulse remains localized.

Influence of Carbon Nanotubes on the Formation of Shock Electromagnetic Waves

Influence of Carbon Nanotubes on the Formation of Shock Electromagnetic Waves

The Influence of Carbon Nanotubes on the Physical and Chemical Properties of Nanocomposites Based on Unsaturated Polyester Resin

The new actual scientific direction is in the development of different nanocomposites and the study of their medical–biological, physicochemical, and physicomechanical properties. One way to expand the functionality of nanocomposites and nanomaterials is to introduce carbon nanostructures into the polymer matrix. This study presents the properties of unsaturated polyester resins (Estromal, LERG S.A.) based on PET recyclate with multi-walled carbon nanotubes (MWCNTs): their mechanical and thermomechanical characteristics, resistance to ultraviolet radiation (UV-vis), and chemical resistance properties. The properties of the obtained materials were characterized using physical–chemical research methods. The changes in the properties of the composites for MWCNT content of 0.1, 0.3, and 0.5 wt % were determined. The results showed positive influences on the thermomechanical and mechanical properties of nanocomposites without significant deterioration of their gloss. Too much CNT added to the resin leads to heterogeneity of the composite structure.

Piezoresistive Characteristics of Carbon Nanotube Polymer Composites with Different Filler Content and Aspect Ratio for Pressure Sensors

Polymer composites enriched with conductive fillers hold immense potential for flexible pressure sensors, because of the remarkable piezoresistive effect they possess. Research on polymer composite pressure sensors has been actively ongoing because of their flexibility and high electrical resistance performance. This paper presents a comprehensive comparison of the piezoresistive characteristics of conductive composites for pressure sensors, focusing on the influence of carbon nanotube (CNT) content and aspect ratio. Polymer composites with conductive fillers, specifically CNTs, have demonstrated significant potential for pressure sensing applications based on the piezoresistive effect. By systematically varying the CNT concentration and aspect ratio, we investigated the impact of these parameters on the piezoresistive behavior of the composites. A pressure in the range of 0-200 kPa was applied to the conductive composite, and resistance change due to pressing was measured. The best performing samples were evaluated in 150 cycle tests to verify repeatability and durability. Experimental analysis and characterization revealed the intricate relationship between CNT content, aspect ratio, and the resulting piezoresistive properties. Through this study, we aim to enhance understanding of how CNT concentration and aspect ratio influence the performance of CNT/PDMS composites as pressure sensors, thereby facilitating the development of optimized sensing materials for various pressure sensing applications.

Influence of carbon nanotubes on microstructure and corrosion performance of additively manufactured 316L stainless steel

Laser powder bed fusion (LPBF) was performed on feedstock-modified 316L stainless steel powder with 1 and 2 vol% carbon nanotubes (CNT). The corrosion resistance was evaluated following cyclic potentiodynamic polarization tests conducted in 0.6 M NaCl at room temperature, 35 and 50 °C, and immersion tests in 6 % FeCl3. The CNT addition has increased the pitting potential and decreased number of pits formed during immersion in FeCl3 solution, which could be attributed to Mn-Si-O nano inclusions refinement and segregation of chromium around the inclusions. The observed corrosion behavior was correlated with the altered microstructure due to CNT addition.

Influence of Carbon Nanotubes on Stability and Vibration Characteristics of Plates and Panels in Thermal Environment: A Review

Influence of Carbon Nanotubes on Stability and Vibration Characteristics of Plates and Panels in Thermal Environment: A Review

On isobaric heat capacity of ionanofluids with carbon nanotubes – An experimental study

Ionanofluids (INFs) are defined as ionic liquids (ILs) with therein dispersed nanoparticles. The addition of nanoparticles results in an increase in the thermal conductivity of INFs. In terms of specific isobaric heat capacity (cp) this influence is not yet clear due to contradictory results published up to date. In this work, we assessed the influence of carbon nanotubes (CNTs) on the cp of INFs by means of DSC. We selected 13 different types of ILs and two mixtures of them as the base for INFs. 9 different types of CNTs were chosen: (singlewalled carbon nanotubes) SWCNTs, helical CNTs, Nanocyl multiwalled carbon nanotubes (MWCNTs) and in-house 16h MWCNTs, MWCNTs functionalized with carboxylic groups (COOH), hydroxylic groups (OH), C18n-alkyl chain or polyethylene glycol (PEG). Functionalized MWCNTs have never been investigated in terms of the cp of INFs. A total of 43 INFs were obtained and studied. The influence of CNTs on the cp of INFs was critically analyzed with consideration to the cp of base liquid and its agreement with data available in the literature, and with consideration to measurement uncertainty. Also, the cp of some pristine CNTs (as a bulk material), namely Nanocyl MWCNTs and in-house 16h MWCNTs, was examined. In the most of systems, the addition of CNTs did not affect the cp of INFs. In the others, the effects were minor and not greater than 3.1 %. In the end, the model proposed to estimate the cp of nanofluid, including the existence of nanolayer of IL on the CNT, was critically examined.

Metal deposited nanoparticles as “bridge materials” for lead-free solder nanocomposites

An influence of carbon nanotubes and carbon nanospheres coated by Au–Pd and Pt on the microstructure of solder/copper joints at room temperature and after aging at sub-zero temperature. The carbon nanosized admixtures were mixed with ternary Sn3.0Ag0.5Cu matrix to prepare a composite solder. The microstructure of the solder joints between the nanocomposite solders and a copper substrate was studied by scanning electron microscopy. It was found that minor (0.05 wt. %) admixtures of both the carbon nanospheres and nanotubes increase the shear strength of the solder joints and reduce the growth rate of the intermetallic Cu6Sn5 layer, formed at the interface between solder and copper. This effect may be related to the adsorption of nanoinclusions on the grain surface during the solidification process. Comparative analysis suggests that exposure for 2 months at 253 K does not lead to deterioration of such an important mechanical characteristic of the solder joint as shear strength, indicating the possibility of using these nanocomposite solders in microelectronic equipment even at temperatures below 0 ℃.

Influence of carbon nanotubes on the plasma electrolytic oxidation process of aluminum under “soft” sparking conditions

Plasma electrolytic oxidation of aluminum (PEO) was performed with dispersed multi-walled carbon nanotubes (MWCNTs) into the electrolyte. The effect of the carbon nanotubes concentration, as well as that of the electrical processing conditions, on the PEO process was investigated. From the point of view of the electrical response of the process, results show that the “soft” sparking regime appears earlier in presence of MWCNTs. The process time at which the transition to the “soft” regime occurs decreases linearly with the increase in the MWCNTs concentration. Over a concentration threshold, depending on the applied pulse bipolar current waveform, the PEO process is inhibited. The dispersion of MWCNTs in the electrolyte results in thicker but more porous alumina layers. More specifically, the proportion of the α-alumina phase relative to the γ-alumina phase decreases with the increase in the MWCNTs concentration. Results are explained by considering the increased coating growth kinetics and lower heat accumulation from MWCNTs addition. Finally, the present study gives new insights into the right management of the PEO process under “soft” sparking regime with dispersed carbon-based nanoparticles in the electrolyte.

The influence of carbon nanotubes and exfoliated graphite nanoplatelets modified by phosphonium‐based ionic liquids on polyurethane composites

AbstractThe effect of the non‐covalent modification of carbon nanotubes (CNTs) and exfoliated graphite nanoplatelets (xGnP) with phosphonium‐based ionic liquids (ILs) on the polyurethane (PU) matrix was investigated. The two ILs used in this work were trihexyl(tetradecyl)phosphonium chloride (IL 101) and trihexyl(tetradecyl) phosphonium dicyanamide (IL 105). The electrical conductivity and electromagnetic interference shielding effectiveness (EMI SE) of PU/CNTs and PU/xGnP composites was strongly influenced upon the loading and dispersion of the conductive fillers in the polymer matrix, as well as the amount and the chemical nature of IL. PU/IL‐xGnP and PU/IL‐CNTs show higher electrical conductivity and EMI SE values when compared to those composites comprising PU matrix with non‐modified fillers. Furthermore, the composites containing modified fillers with IL105 exhibited higher electrical conductivity and EMI SE values than those with IL101. This behavior was due to the better interaction of the dicyanamide counter anion (IL 105), which interacts more efficiently with the PU matrix than the chloride anion (IL 101). The hybrid composites (PU/IL‐CNT/IL‐xGnP) displayed higher electrical conductivity and EMI SE than those found for hybrid composites without ILs. Hybrid composite with a proportion of 75/25 of CNT/xGnP modified with IL 105, displayed EMI SE values adequate for commercial applications. These results highlight that these hybrid composites containing CNT/xGnP modified with trihexyl(tetradecyl) phosphonium dicyanamide are promising materials for electromagnetic shielding.

Amendments of weld formation in human skin laser soldering.

A computational modeling is employed for quantitative assessment of weld formation and area of tissue temperature necrosis during the human skin laser soldering. The evaluation is carried out depending on the components composition of using solders, including bovine serum albumin (BSA), indocyanine green (ICG), and carbon nanotubes (CNT), as well as the angle of incidence of laser light and its pulse duration. The influence of CNT on the change of thermodynamic characteristics of albumin denaturation and the rate of formation of the laser weld is investigated. The obtained results suggest to limit the duration of laser light pulse by temperature relaxation time to minimize transfer of thermal energy to reduce the heating of human skin tissues. The developed model has a great potential for further optimization of laser soldering of biological tissues technology with greater efficiency in minimizing the weld area. This article is protected by copyright. All rights reserved.

Investigation of coated 316L steel surface employing carbon nanotubes mixed-electrical discharge machining for biomedical applications

This research focuses on the influence of carbon nanotubes on the modified 316L steel surface properties for potential biomedical applications and explores relationships between the process variables and the modified surface properties. Following Taguchi's L9 (3^4) design, carbon nanotube is added in the electro-discharge machining oil to synthesize a biocompatible and hard coating when the machining of 316L steel with a titanium electrode. A few characterization tools such as scanning electron microscope, goniometer, Vickers's hardness, x-ray diffraction (powder X-ray diffraction), atomic force microscope, energy dispersive X-ray, and MTT ((3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, a tetrazole) assay were adopted for performing the modified surface characterizations. A thin coating of 14.65 µm attributing to a small contact angle of 58.97° is found. The lowest surface roughness of 1.63 µm in micron scale and 5.641 nm in nano scale is obtained at a low both current and carbon nanotube amount applications. The morphological results confirm a crack-free, micro and nano porous surface. Compositional analysis ensures carbides, intermetallic and oxides formation on the coated surface. Microhardness of 316L steel is improved by about 86% (269.8 HV). Most importantly, approximately 70% cells are alive, which witnesses the use of carbon nanotube in biocompatible coating formation.

Effect of Carbon Nanotubes (CNTs) on the performance of Solid Rocket Propellants (SRPs): A short review

Burning rate catalysts (BRCs) are usually utilized to adjust the burning rates of solid rocket propellants (SRPs). Carbon nanotubes (CNTs), for their unique structure and properties, have been studied by several researchers worldwide with a wide range of applications. In this paper, several worthy CNTs-based materials and effects are described. Specifically, the influence of CNTs on the thermal behavior of energetic materials (EMs) are discussed, and we investigated the impact of CNTs/metal (metal oxide, MO) composites on the thermal degradation of EMs. Applications for SRPs and solid rocket nozzle motors might benefit from a focus on the examination of the burning rate, pressure exponent characteristics, and hazardous aspects. It was discovered that CNTs, as opposed to the comparable micro-sized additives, can modify the combustion behavior and speed up the burning of SRPs. Lastly, the difficulties encountered in implementing some of these applications are also examined in terms of manufacturing, processing, pricing, and potential future uses.