CNT Content Research Articles

Carbon nanotube heat absorber for efficient direct-heating of liquid tin in a solar receiver

A new approach that use vertically-aligned carbon nanotubes (VACNT) as heat absorbers is proposed for efficient direct solar heating of liquid tin in a solar receiver integrated with beam-down optics. Plate-type CNT heat absorbers were prepared by adjusting the concentration of CNTs in the processing solvent m-cresol. The prepared CNT absorber exhibited an increase in bulk density and the formation of a densely packed nanotubes skeleton with a higher CNT concentration in m-cresol. Thermal conductivity, a key design factor for solar absorbers, showed a stronger correlation with skeletal density than with bulk density. Heat absorption characteristics of the solar liquid tin receiver (50 mm-i.d., 60 mm-high) with the CNT absorbers integrated with a Fresnel lens (0.98 m i.d.) were determined. The tin temperature in the receiver with the CNT absorber reached a maximum of 728 °C. Bare tin exhibited system efficiency of 27.7 % and receiver efficiency of 38.3 %, but tin heating through the CNT plates exhibited system efficiency of up to 48.4 % and receiver efficiency of 64.3 %, showing a system heat absorption rate 1.75 times higher. The thermal absorption efficiency was proportional to the skeletal density of the plates, and the thermal absorption of the system was dominated by the efficient transfer of absorbed heat in the energy absorption region. The energy flow and heat loss in the receiver system were analyzed. Although the bare tin receiver exhibited a high heat loss of 27.1 % owing to the low emissivity or high reflectivity of the tin surface, the heat loss in the CNT absorber plates with high absorptivity was only 0.9 %. The flat plate-shaped transmission window in the receiver caused significant reflective heat loss and convective heat loss owing to head-on wind. Based on the energy flow analysis, improvement approaches for enhancing the thermal efficiency of the proposed receiver system are suggested.

Properties of polyphenylene sulfide/multiwalled carbon nanotubes composites: a comparison between compression molding and microinjection molding

Abstract This work comparatively studied the electrical, morphological, and thermal properties of polyphenylene sulfide/multiwalled carbon nanotubes (PPS/CNT) composites which were prepared by compression molding (CM) and microinjection molding (μIM), respectively. The subsequent samples were termed as CM composites and microparts, respectively. Results revealed that the electrical conductivity of PPS/CNT microparts was lower than that of CM PPS/CNT composites, which was ascribed to the difference in shearing influence that affected microstructural evolution in resultant moldings. In addition, SEM observations revealed that the distribution of CNTs became better in the PPS/CNT microparts, which was related to the prevailing higher shearing effect in μIM. The tensile strength of PPS/CNT microparts dropped for filler concentrations ≤2 wt% and it started to increase after that reached 10 wt%; in comparison with the PPS/CNT microparts, the tensile strength of CM PPS/CNT samples exhibited an opposite trend when the filler concentration was ≤3 wt%. After that, the tensile strength of CM samples showed a monotonic increase with increasing CNT concentrations. Both the uniform distribution of CNT and increase of crystallinity were crucial to improving the tensile strength of PPS/CNT moldings. This work showed that PPS/CNT moldings with good electrical conductivity and mechanical performance can be molded at relatively high filler concentrations, which is critical for applications in demanding engineering sectors.

Optimization of FFF process parameters to improve the tensile strength and impact energy of polylactic acid/carbon nanotube composite

AbstractIn this study, the process parameters of fused filament fabrication are optimized to improve the tensile strength and impact energy of polylactic acid/carbon nanotube (PLA/CNT) composite. Hence, the utility function (UF) technique and response surface method (RSM) are applied to explore the optimal levels of the effective parameters of print speed, nozzle temperature, and CNT content. The differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and SEM analyses are employed to examine the thermal properties of the printed samples. The results of DSC and TGA analyses exhibited that the incorporation of CNT into PLA enhanced the thermal strength of PLA/CNT composite. The addition of CNTs in the composite improved the tensile strength by 37%, while the addition of CNTs up to 4 wt% improved the impact energy by 29%. Moreover, an increment of the print speed to 60 mm/s reduced the impact energy (12%) and tensile strength (22%), while an increment of the nozzle temperature to 200°C enhanced the impact energy (9%) and tensile strength (12%). The optimization results demonstrated that the strength and impact energy of PLA/CNT composite optimized at CNT content of 2.8 wt%, print speed of 20 mm/s, and nozzle temperature of 209°C. Additionally, the impact energy and tensile strength of the PLA/CNT composite enhanced up to 62.5 MPa and 2.14 J at the optimum conditions.Highlights Application of FFF process for producing the PLA/CNT composite Investigating the impact of FFF parameters on the mechanical properties Estimating the optimal conditions of the FFF process

One-Step Fabrication of Semi-Transparent Nanofibrous Lithium-Ion Battery

Flexibility and transparency of batteries greatly expand their application and offer new opportunities to electronic devices making them foldable, bendable, and not obstracting. Herein was proposed a facile and beneficial strategy to solve “hot” issues of such type of batteries by providing a uniform and stable framework for bendable, portable and semi-transparent "all-in-one" lithium-ion batteries (LIBs). The “all-in-one” flexible LIB was fabricated by one-stage electrospinning of PEO and PVDF-HFP-based precursor solution loaded with active materials. The electrochemical performance of the anode and cathode membranes was investigated in lithium half cells. To improve the electron-conductivity, CNTs were introduced inside the nanofibers in anode and cathode parts. The nanofibers containing active materials were successfully fabricated with the use of pre-synthesized nanosized LFP/C and graphite powders and loading them into the electrospinning solutions of the cathode and anode, respectively. The use of the same polymer to produce all three parts of the battery (anode, separator and cathode), as well as optimized electrospinning conditions, made it possible to obtain all-in-one flexible solo membrane. The concept was based on the application of nanofibers containing pre-synthesized active materials without carbonization, sintering or any other post-treatment. The developed “all-in-one” membrane assembled within copper and nickel meshes acting as anodic and cathodic current collectors demonstrated semi-transparency as can be seen from the figure. It is enabled by the swollen polymer fibers network, which provides transparent substrate for nano-sized particles of active materials. Additionally, the thin metallic mesh used as current collectors could maintain the overall transparency of the cell. Alternatively ITO glass and/or membrane with high content of CNT were used as a current collectors to provideimproved transparency and flexibility. Acknowledgment This research is funded by the Committee of Science of the Ministry of Science and Higher Education of the Republic of Kazakhstan (Grant No. BR21882402) Figure 1

(Invited) Electron Transport in Nanocarbon Networks for Energy Conversion and Storage Applications

Carbon nanostructures have attracted great attention in recent years as novel electrode materials in batteries with increased capacity and conductivity as well as enhanced material stability. In these nanostructures, nanocarbons such as carbon nanotubes and graphene nanoplatelets are interconnected to construct their three-dimensional networks around the host materials for Li deposition. This work focuses on the study of electron transport phenomena in these nanocarbon networks with two model material systems: (1) single-walled carbon nanotube (SWCNT) networks co-embedded with silica microparticles (Fig. (a)), and (2) free-standing three-dimensional graphene (3DG) structures with polymeric surface modifications (Fig. (b)). We characterize the materials for electrical conductivity and thermopower with varying material contents in the composites to reveal several key factors determining their energy-dependent carrier transport characteristics. It is found that in these three-dimensional nanocarbon networks, carrier tunneling at the junctions between nanocarbons along with the network morphology predominantly determines the transport properties. Simultaneous increase in electrical conductivity and thermopower is achieved for SWCNT networks co-embedded with silica microparticles by increasing silica content up to 40 w.t.% at a fixed CNT content. The enhanced electron transport is attributed to the reduced junction distances due to the intimate network formation on the surface of silica particles with a polymer binder. Our transport theory based on the Landauer formalism for junction tunneling reveals that the junction modification with polymer can alter the potential barrier heights for both electrons and holes at the junction to significantly change the transport properties of the composite. Doping of nanocarbons is also investigated for their impacts on the junction transport and the geometric factor of the networks. Finally, we also investigate the use of these carbon nanostructures in solid-state thermoelectric (TE) energy harvesters and ionic TE capacitors to harvest thermal energy from temperature gradients and fluctuations. Figure 1

Flexible Screen‐Printed Thermoelectric Materials Based on PEDOT:PSS/DWCNT Composites

AbstractScreen printing technology is employed to prepare poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS)/double‐walled carbon nanotubes (DWCNT) films as active p‐type material for flexible thermoelectric generators (TEGs). Performance of the PEDOT:PSS/CNT composites have been optimized by changing the formulation inks to make them suitable for screen printing, by varying the CNT concentrations and by treating the printed polymeric films in ethylene glycol (EG). The purpose of this work is finding the processing conditions that optimize conductivity, Seebeck coefficient, and the power factor of the fully printed material. From experimental data, the composite with 10% by weight of DWCNT chemically treated in EG maximizes conductivity, Seebeck coefficient, and power factor of the material.

Unveiling the high strength and ductile character of reinforced CNT/geopolymer paste subjected to elevated temperatures

A significant challenge in developing suitable advanced materials in the construction sector is urgent face to the natural disasters affecting our infrastructure and endanger the world population. At this stage, geopolymers renowned as a green and low-carbon material has received considerable attention. Here, novel properties are revealed for Na-based and K-based metakaolin geopolymer paste reinforced by carbon nanotubes with various dosage, exposed to high temperatures. Results show that adding 1.08 wt% of CNT makes the geopolymer matrix thermally stable and resistant up to 1327 °C. It comes out that geopolymer nanostructure with low CNT concentration became tough to shear deformation along (001) plane up to 1127 °C and is easier to shear along (100) plane for highest CNT content. Calculations predict that low CNT dosage double the ductility of Na-based and K-based geopolymer matrix at room temperature. Heating up to 1327 °C enhances the stiffness of both nanostructures. The micro-hardness doubles at 800 °C for Na-based rather than K-based geopolymer matrix when adding low CNT dosage.

Wear characteristics of a CNTs reinforced aluminium composited fabricated by the solution mixing process

Aluminium-carbon nanotube (Al-CNT) composites have proven to offer a lot of potential for applications involving friction and wear. This study investigated the wear behaviour of Al-CNT composites with uniformly dispersed CNTs without structural damage at concentrations of 0.5 wt%. The wear behaviour of these composites has been compared with that of pure aluminium, which was fabricated using the identical wet shake mixing, compaction, and extrusion procedure. The study aimed to determine how CNT concentration and applied stress influence the wear behaviour of composite materials. Scanning electron microscope (SEM) was used by the researchers to examine the surface features of the worn samples. The study showed a significant increase in hardness and wear resistance with adding CNT. Compared to pure aluminium, the composite containing 0.5 wt. % CNTs demonstrated a 25% reduction in wear rate, and the average value of the coefficient of friction (µ) also decreased. The wear rate and coefficient of friction increased when samples containing 0.5 wt. % CNTs were subjected to various loading scenarios. The major contribution of CNTs to improving wear characteristics was discovered through SEM investigation of these worn surfaces. Using the ANSYS Workbench, a built finite element model was used to perform contact analysis on the disc and pin. Analytical results and experimental data were contrasted, and the ANSYS data was utilised to assess the process parameters. The comparison confirmed the analysis accuracy and dependability, which showed a consistent agreement between the analytical findings and the experimental results.

Surface modification of CNTs through the SiO2 coating to increase the intragranular reinforcement content in Al matrix composites

Surface modification of CNTs with SiO2 coating was proposed to fabricate Al matrix composite with high-content intragranular reinforcements. The deposition of SiO2 nanoparticles on the surface of CNTs improved their compatibility with the Al matrix and thus increased the penetration of CNT@SiO2 reinforcements into Al grain interiors during powder processing. The intragranular reaction during the sintering process converted the CNT@SiO2 hybrid reinforcements into Al4O4C nanoparticles, leading to a remarkable increment in reinforcement content. As a result, incorporating CNT@SiO2 reinforcements (0.5 wt% CNT coated with 2 wt% SiO2) into Al resulted in a final composite with 9 vol% nanoreinforcement, of which 85 % were located in the grain interiors. The high-content intragranular reinforcements greatly improved dislocation storage capability and strain hardening rate, resulting in a significant increase in strength while retaining good ductility. The composite's yield strength and tensile strength increased to 370 MPa and 472 MPa, respectively, which were about 66 % and 67 % higher than those of the CNT-Al composite with the same CNT content.

The capacitance and shape memory effect of highly stretchable and flexible nanocomposite electrodes based on polyaniline

AbstractThe increasing demand for portable and flexible energy storage devices drives the rapid development of flexible electrodes and electrolytes. Meanwhile, the free‐standing polymer electrodes face great chance and challenge. In this work, the stretchable and flexible polyaniline/carbon nanotube/poly(vinyl alcohol) electrode (PANI/CNT/PVA‐E) was fabricated by in‐situ polymerization of aniline in CNT/PVA‐E substrate, where CNT was used to enhance the conductivity and mechanical properties of the polymer electrodes. Compared with PANI/PVA, the comprehensive performance of PANI/CNT/PVA‐E was improved. In addition, the electrochemical performance and tensile property of the electrodes depended on the CNT content. The nanocomposite electrode with 0.25% of CNT possessed optimal properties with high capacitance of 248.69 mF cm−2, and 75.29% of capacity retention over 4000 charge–discharge cycles at 1 mA cm−2. It also exhibited outstanding tensile strength of 3.88 MPa and elongation up to 462.3%. Interestingly, the electrode possessed good heat driven shape memory effect. The temporary shape could be fixed at 70°C under extra force, and the fixed shape recovered within 10 s when it was reheated to the same temperature. It is concluded that the present work may contribute to the development and fabrication of flexible energy‐storage devices, portable and highly stretchable electric devices.

Influence of CNT Concentrations on Structural and Morphological Properties of PANI-SnO2-CNT Nanocomposite Thin Films and the Sensitivity Performance to Detect E. coli in Water

Influence of CNT Concentrations on Structural and Morphological Properties of PANI-SnO2-CNT Nanocomposite Thin Films and the Sensitivity Performance to Detect E. coli in Water

Predicting effective elastic modulus of CNT metal matrix nanocomposites: A developed micromechanical model with agglomeration and interphase effects

Agglomeration and interphase region of fillers are two important factors that affect the mechanical properties of metal matrix composites reinforced with carbon nanotubes (CNT-CMMs). However, most of the existing theoretical models predict an ascending linear in strength for composites with increasing filler content, which disagrees with the experimental results, especially at high filler loading. In fact, at high CNT concentrations, agglomeration and weak interphase region bonding reduce the strength and consequently degrade the mechanical properties of composites. Based on the mean-field theory, we present a novel micromechanical model to predict the elastic modulus of CNT-CMMs by considering the effects of these two factors. Furthermore, we investigate the effect of other parameters such as CNTs aspect ratio, agglomeration amount, interphase layer thickness and modulus, and matrix modulus on the elastic modulus of CNT-CMMs. Finally, we validate our model by comparing it with numerous experimental outcomes from the literature signifies good precision. Using this model, it is possible to optimize the filler value and also maximize the elastic modulus, which can be a powerful tool for designing the CNT-CMMs.

CNT/TiO2 nanocomposite for environmental remediation

Abstract Nanomaterials and their composites have been proven to be effective materials for various energy and environmental applications. In this way, functionalized polymers and their nanocomposites (NCs) are receiving much attention due to their tunable physico-chemical characteristics, cost and ease of availability. As an environmental application, particularly the removal of toxic dyes, photocatalysis has been reported as an emerging technology. The literature survey shows that functionalized polymer nanocomposites (PNCs) as photocatalysts offer an extensive contribution towards the generation of clean, renewable, and practical forms of energy from light-based pollutant removal as environmental remediation. Here, the present concept provides a brief introduction to the field of photocatalysis and environmental remediation, followed by the application of functionalized PNCs. In this view, TiO2–NCs are reported to be effective photocatalytic materials. In the present study, CNT-doped TiO2 NCs samples have been prepared using the sol–gel method and their photocatalytic activity has been investigated through a dye degradation experiment. Compared to the present studies, here the CNT content taken is very low, and it is found to be effective for the dye degradation part of an environmental cleaning application.

Improving the electrical conductivity of multiwalled carbon nanotubes‐containing micromoldings via in situ construction of electrically conductive networks

AbstractMicroinjection molding (μIM) is characterized by high shearing and cooling rates, resulting in higher a degree of filler orientation which impairs the electrical conductivity (σ) of conductive filler‐containing polymer composites when compared with that of compression molding and conventional injection molding processes. In this study, polypropylene/polyamide 6/multiwalled carbon nanotubes (PP/PA6/CNT) composites were used as the model system to investigate how blending sequence, injection speed, and component mass ratios affected the morphology and σ of PP/PA6/CNT microparts. The results demonstrated that CNTs exhibited a higher affinity for the polar PA6 phase and they tended to be preferentially distributed in PA6 domains. The deformation and coalescence of CNT‐rich PA6 phase promoted the creation of an intact and continuous filler network structure along the flow direction under the influence of high shearing conditions in μIM. When the mass ratio of PP:PA6 was 70:30 and the concentration of CNT was 7 wt%, the micropart possessed the highest σ (1.2 × 10−6 S/m) when compared with their PP/CNT (4.4 × 10−9 S/m) and PA6/CNT (3.4 × 10−10 S/m) counterparts. Higher injection speeds resulted in higher degree of CNT orientation, which negatively affected the σ of subsequent moldings. This work established an approach for producing electrically conductive microparts that demonstrate promising applications in the fields of electronics, automotive, and microsystems among others.Highlights PP/PA6/CNT composites were used as model systems for microinjection molding. The electrical conductivity was improved by shear‐induced deformation of CNT‐rich phase. The properties of PP/PA6/CNT microparts were affected by process parameters.

Towards developing advanced CFRP with simultaneously enhanced fracture toughness and in‐plane properties via interleaving CNT/PEI hybrid veils

AbstractCarbon nanotube (CNT)‐polyetherimide (PEI) hybrid nanofibrous veils were prepared through the electrospinning process to function as an interlayer in carbon fiber reinforced polymer composites (CFRP), and the effects of the addition of the hybrid fiber veils on the interlaminar fracture properties and flexural properties of CFRP were investigated. The results showed that interleaving CNT/PEI hybrid veils can effectively avoid long‐troubled trade‐off between mode‐I interlaminar fracture toughness and in‐plane properties when using thermoplastic toughening materials. Specifically, the GIc value and flexural strength of the laminates were increased by as much as 86.2% and 14.3%, respectively when CNT content was reached up to 0.7 wt% in CNT/PEI hybrid veil. This method adopts ultra‐low PEI and CNT additions, and the limited quantity of these additives demonstrates a notably high interlaminar toughening efficiency while concurrently enhancing the strength, rendering it a promising strategy for both toughening and strengthening.Highlights PEI is used as a carrier to transport CNT to the CFRP interlaminar layers. PEI‐CNT hybrid fiber veils improve GIC and flexural strength of CFRP. PEI‐CNT hybrid fiber veils impede crack expansion through various mechanisms. This method adopts ultra‐low PEI and CNT additions.

Facile and efficient fabrication of carbon nanotube reinforced epoxy vitrimers through dynamic crosslinking

AbstractCarbon nanotubes (CNT) is an ideal candidate for reinforced epoxy vitrimer composites, however, achieving a desirable improvement of the mechanical properties is a great challenge owing to CNT is extremely easy to aggregate. In this study, well‐dispersed CNT reinforced epoxy vitrimers, namely EVD/CNT, were prepared by combining ultrasonic dispersion and dynamic crosslinking techniques, using multiple wall carbon nanotube as reinforcement filler, sebacic acid as curing agent, diglycidyl ether of bisphenol A (DGEBA) as epoxy monomer, zinc acetylacetonate as transesterification catalyst, torque rheometer (internal mixer) as dynamic crosslinking equipment. The CNT reinforced epoxy vitrimers, namely EVS/CNT, were prepared using traditional static curing method. The structure and morphology, mechanical properties and stress relaxation behavior of EVS/CNT and EVD/CNT were comparatively investigated, and the influence of CNT content on the structure and properties of EVD/CNT prepared by dynamic crosslinking method were also studied. The results indicated that dynamic crosslinking technology can stably disperse CNT into epoxy vitrimer resin matrix under continuous shear force. However, CNT experienced severe secondary agglomeration during the static curing process. When the loading amount of CNT was 2 wt%, the tensile strength and elongation at break of EVD/CNT‐2 were 3.2 times and 2.2 times higher than those of EVS/CNT‐2, respectively. The Young's modulus and glass transition temperature (Tg) of EVD/CNT‐2 (6.43 ± 1.10 MPa, 29.6°C) were also higher than those of EVS/CNT‐2 (5.46 ± 0.31 MPa, 25.4°C). Moreover, dynamic crosslinking technology greatly shortened the reaction time of CNT reinforced epoxy vitrimers, improved production efficiency and reduced reaction energy consumption, and was expected to be used for large‐scale and industrial production.

Cationic UV-curing of bio-based epoxidized castor oil vitrimers with electrically conductive properties

The growing appeal of carbon nanotube composites in the contemporary market derives from their exceptional thermal and chemical stability, coupled with electrical conductivity. In this study, we combined these salient features with a biobased epoxy matrix having vitrimeric properties, hence being reprocessable and resheapable, to obtain a biobased conductive coating. Epoxidised castor oil (ECO) was chosen as a monomer precursor for the straightforward synthesis. The synthesis relied on a cationic UV-curing process, embedding the conductive carbon nanotubes in the matrix. Photo DSC and transmission FTIR analysis were conducted to determine the final conversion of the epoxy rings in the cationic photocuring process. Thermo-mechanical properties were evaluated by tensile tests, and DMTA. Thermal stability was assessed by TGA. Dielectric spectroscopy confirmed increased electrical conductivity in the presence of increasing CNT content, reaching a percolation threshold at 0.5 phr of CNTs. Vitrimeric properties were proved by stress relaxation experiments, and the UV-cured composite underwent a thermo-activated transesterification reaction starting from 70 °C, catalysed by dibutyl phosphate. Overall, the ECO-CNT composite showed high thermal resistance (up to 400 °C) electrical conductivity with 0.5 phr CNT concentration, and vitrimeric properties. The study can be, therefore, considered a promising starting point to obtain sustainable biobased and electrically conductive vitrimers.

Mapping carbon nanotube aspect ratio, concentration and spinning in FCCVD synthesis controlled by sulphur

Floating catalyst chemical vapor deposition (FCCVD) enables ultrafast synthesis of CNTs and other 1D nanoparticles and their direct assembly as macroscopic solids. The chalcogen growth promotor in FCCVD produces high aspect ratio CNTs that can aggregate in the gas phase and form an aerogel which can be continuously spun as macroscopic fibres or sheets. We study the role of sulphur in controlling CNT morphology and aggregation by synthesising CNTs under a wide range of S/C ratios (0.001 to 5 wt.%) and determining their diameter and length distributions, number concentration and form of aggregation. Increasing S/C ratio in this range increases mean number of CNT walls from 1 to 8, decreases mean length from 34 to 6 µm, but CNT number concentration remains approximately constant at 8 × 108#/cm3. Assuming growth within the first 3 cm of the reactor, longitudinal growth rate spans 1.5- 6.5 µm/s for the different CNT morphologies, but with similar mass throughput of 700 attogram/catalyst. This indicates the amount of carbon reaching the catalyst and solidifying as CNT remains constant regardless of the sulphur available in the catalyst, suggesting the rate limiting process is not at the catalyst/promoter interface but instead in the transport of carbonaceous active precursors to the catalyst, either due to their diffusion in the gas phase or decomposition kinetics. The CNTs produced range from polymer-like, which readily bundle and form aerogels, to rod-like that do not. We include aerogelation “phase diagrams” for different CNT concentrations, aspect ratios and CNT bending stiffness.

Assessment of physical and mechanical properties of concrete with carbon nanotubes pre-dispersed in cement

The expanding field of nanoengineering modification of cementitious materials increasingly supports advances and innovations in science and engineering through nanotechnology. In this context, this research evaluates the physical and mechanical properties of concrete with carbon nanotubes (CNT–concrete), including compressive strength (CS), tensile strength (TS), static (Es) and dynamic modulus of elasticity (Ed), water absorption (WA), porosity (P), bulk density (ρap), weight loss (WL), ultrasonic pulse velocity (UPV), and electrical resistivity (ER). Specifically, this paper investigates the correlations between these properties and proposes quadratic regression models based on CNT contents to estimate them. For this, an extensive experimental campaign was carried out. As a novelty, CNT were pre-dispersed in the cement particles in an isopropanol to produce the concrete, a proven effective process but used only in pastes and mortars so far. Concrete samples were produced with CNT contents of 0 % (as a reference), 0.05 %, and 0.10 % by weight of cement, with 30 cylindrical specimens measuring 100 × 200 mm (diameter × height) being molded for each composition. The results revealed that including 0.05 % CNT led to statistically significant results, such as reductions of up to 12 % in P and 14 % in WA and increases of up to 16 % in CS, 29 % in TS, and 3 % at UPV. At 0.10 % CNT, Ed showed up to 10 % improvements, while WL increased to 28 %. It was also shown that pre-dispersing powdered CNT in cement particles using an isopropanol medium is effective for use in concrete, but dispersing CNT in water is simpler, safer, and potentially more efficient, especially for industrial production. Another important conclusion was the identification of significant correlations between some properties, which varied with the amount of CNT added, suggesting the existence of a CNT saturation point. Furthermore, the regression models identified ideal CNT contents for P, WA, CS, TS, and UPV, ranging between 0.045 % and 0.123 % CNT. This research also points to the need for additional studies to improve the quality of the regression models and thoroughly assess the benefits of incorporating CNT into concrete studies.

Investigating Corrosion and Surface Hardness of Al6061 in Machining Fluids with Variable CNT Concentrations

Investigating Corrosion and Surface Hardness of Al6061 in Machining Fluids with Variable CNT Concentrations