Multi-walled Carbon Nanotubes Nanoparticles Research Articles

The effects of 1D multi‐wall carbon nanotubes and 2D graphene nanoplatelets on curing behavior of epoxy/vinyl ester interpenetrating polymer network nanocomposites

AbstractThis study meticulously investigated the effect of two carbon allotrope nanofillers, two‐dimensional graphene nanoplatelets (GnPs) and one‐dimensional multi‐wall carbon nanotubes (MWCNTs) individually, at various loadings on the kinetics of curing of the epoxy (EP)/vinyl ester (VE) based interpenetrating polymer network (IPN) system, with a mass ratio of 1:1. The IPN system is including a liquid epoxy resin based on bisphenol A which has been cured by methyltetrahydrophthalic anhydride (MTHPA) in the presence of 1‐methyl imidazole (Mi) as an accelerator and a vinyl ester resin based on bisphenol A which has been cured by methyl ethyl ketone peroxide (MEKP). The curing behavior of all prepared nanocomposites under non‐isothermal conditions was studied using DSC at four heating rates. Two different isoconversional approaches were applied to evaluate the reaction kinetics, that is, the Friedman and the advanced Vyazovkin methods. The obtained activation energy curves for all samples revealed a complex curing behavior involving three stages: early IPN stage, IPN growth stage, and late IPN stage. Then, the activation energy values for each reaction step were determined based on the Friedman method. The presence of GnPs showed no catalytic effect on the reaction of VE with MEKP. In contrast, incorporating MWCNT nanoparticles considerably decreases the activation energy values of the reaction of ring opening of epoxides with MTHPA‐Mi and the reaction of esterification of the hydroxyl groups of VE with MTHPA.Highlights MWCNTs reduce activation energy in curing reactions for EP/MTHPA‐Mi and VE/MTHPA. GnPs do not catalyze VE/MEKP reaction unlike MWCNTs. Combining MWCNTs and GnPs enhances properties of IPN nanocomposites. Curing process includes early, growth, and late IPN stages impacting activation energy. SEM analysis reveals better dispersion of GnPs in IPN nanocomposites with MWCNTs.

Experimental investigation of performance, emission, and combustion characteristics of a diesel engine using blends of waste cooking oil-ethanol biodiesel with MWCNT nanoparticles

In this study, blends of 5 % and 10 % ethanol with waste cooking oil biodiesel are mixed with Multi-Walled Carbon Nanotubes (MWCNT) at a concentration of 30 ppm. MWCNTs, known for their high surface area and unique properties, are added to potentially enhance combustion efficiency and reduce emissions. These blends are then tested in a diesel engine to evaluate their performance, emission and combustion characteristics using Design of experiment technique. After conducting various experiments and analyses, the blend of 20 % biodiesel, 10 % ethanol, and 30 ppm MWCNT was identified as the most optimal due to its favorable engine characteristics. Brake Thermal Efficiency (BTE) was increased from 3.1 % to 3.4 % with the addition of MWCNTs, indicating enhanced fuel efficiency. Moreover, average Fuel Consumption is decreased from 2.2 % to 2.5 %, suggesting improved fuel utilization. Using MWCNT 30 ppm in B20 ethanol blends (MWCNT 30 ppm B20+E10) resulted in 35 % reduction in nitrogen oxide (NOx) emissions, 37 % reduction in CO emissions and 39 % reduction in HC emissions. Hence MWCNTs demonstrated effectiveness in mitigating harmful exhaust emissions The optimized values for all parameters fall within acceptable ranges, indicated successful optimization using Response surface methodology. Additionally, statistical analysis reveals that the machine learning- XGBoost model outperformed all other advanced machine learning models across all tested metrics, including MSE, MAE, and R-square.

Enhanced heat transfer in novel star-shaped enclosure with hybrid nanofluids: A neural network-assisted study

The current research is a numerical investigation of the thermo-fluidic transport trend within a new star-shaped enclosure filled with Fe3O4−MWCNT (Multiwall Carbon Nanotubes) suspended hybrid nanoparticles in a base fluid (water), induced by a horizontal magnetizing field. A rectangular rod inside the cavity positioned at center is kept at a high temperature, as the low temperature is chosen for outer corrugated boundary. Formulation yelled in mathematical principles, along with the boundary conditions and some physical assumptions, are formulated as dimensionless PDEs. The finite element method (FEM) assisted by “COMSOL” software, employed for numerical simulations, and the PARDISO solver is used for solving nonlinear system of equations. Also, an artificial neural network (ANN) model is assembled to analyze the effect of these parameters on thermal and flow transport properties of Hybrid nanofluid. The training of this ANN model is done by a dataset generated from numerical simulations, suggesting predictions regarding heat transport under varying parameters. This approach does not only reduce the effort, but also reduces computing time when exploring the thermal behaviors across various datasets. The visualization of velocity and temperature fields through streamlines and isotherms, along with the evaluation of the Nusselt number, illustrate the enhanced heat transfer facilitated by the incorporation of Fe3O4−MWCNT nanoparticles. The results show that increased magnetic field strength reduces fluid velocity due to the generated Lorentz force, which counteracts convective flow. Percentage analysis indicates that hybrid nanofluids (Fe3O4−MWCNT) significantly improve thermal distribution compared to conventional fluids. This study demonstrates the effectiveness of ANN models in forecasting the influence of diverse factors on the flow and heat transport characteristics of hybrid nanofluids. These insights are essential to the design and optimization of heat transfer systems.

Amplifying thermal performance of solar flat plate collector by Al2O3/ Cu/MWCNT/SiO2 mono and hybrid nanofluid

Flat plate collectors (FPCs) have garnered widespread usage in applications such as water heating, space heating, and various thermal systems, presenting an eco-friendly and sustainable approach to harnessing solar energy. However, the thermal performance of FPCs has been adversely affected by the improper selection of Heat Transfer Fluids (HTFs). The purpose of the work is to explore and demonstrate the potential advancements in solar flat plate collector (FPC) technology through the use of nanofluids to Enhance Energy Conversion, Explore Synergistic Effects, Contribute to Sustainable Energy Solutions and Address Technological Challenges. That is to optimize the thermal performance of FPCs by incorporating standalone and hybrid nanoparticles into the base fluid to augment their thermal properties. This approach explores new possibilities for synergistic effects and enhanced thermal properties, offering a novel contribution to the field of nanofluid research. The standalone and hybrid nanofluids encompass nanoparticles such as Al2O3, Cu, multi-walled carbon nanotubes (MWCNT), and SiO2 at a concentration of 0.5 wt%. In the preparation of hybrid nanofluids, equal volume fractions (25 % each) of Al2O3, Cu, MWCNT, and SiO2 nanoparticles were employed. The investigation includes the evaluation of thermal performance parameters, namely heat gain, heat loss coefficients, and thermal efficiency of FPCs, comparing these values with those of water. Hybrid nanofluids exhibit significantly improved thermal performance compared to both plain water and monodisperse nanofluids. Employing hybrid nanofluids yields results that indicate a peak outlet temperature of approximately 83.2 °C, a higher heat gains of 2385 W, a reduced heat loss coefficient of 25.5 W/m2K, and a peak thermal efficiency of 70.4 %. The use of hybrid nanofluids, as opposed to monodisperse nanofluids, offers superior thermal performance for flat plate collector-based solar heating systems.

Experimental Investigation for Enhancement of Heat Transfer Coefficient in Car Radiator by Using Multiwall Carbon Nanotube (MWCNT) Nanofluid

Improving heat transfer coefficient is a significant subject of study in many engineering domains. The use of nanofluids in car radiators might boost the heat transfer coefficient. The current study investigates a car's radiator's heat transfer coefficient and thermal conductivity. The heat transmission parameters of a car radiator were analyzed for coolant mass flow rates ranging from 600 to 1200 liters/hour and nanofluid concentrations ranging from 0.2 to 0.8% by volume. The primary coolant was prepared by combining water and ethylene glycol in a 60:40% combination with multi-walled carbon nanotube nanoparticles. The coolant's input temperatures were varied between 30 °C and 80 °C by impinging an air jet into the car radiator through a hallow cone nozzle plate with and without spacing. The result demonstrates that the volume flow rate of coolant on the tube side increases considerably as the heat transfer coefficient increases. At a nanoparticle concentration of 0.8 vol. %, the nanofluid's total heat transfer coefficient is enhanced by 12% compared with the base fluid. The heat transfer coefficient is improved by 42.6% for 0.8% volume of MWNCT nanofluid without spacing of the hallow cone nozzle plate and by 51.9% with spacing of the hallow cone nozzle plate.

Impact of nano-hybridization on flexural and impact behavior of basalt/glass fiber-epoxy composites for automotive structures

This study’s primary objective is to experimentally investigate the flexural and impact performance of composites composed of hybrid basalt/E-glass fiber-reinforced epoxy infused with multiwalled carbon nano-tubes (MWCNTs) and nano-silica (SiO2) in compliance with ASTM D790 and ASTM D6110 specifications. Recently, manufacturers considered using basalt fiber-based composites for various structural applications due to their excellent mechanical properties, high stiffness, and high strength-to-weight ratio. Each composite laminate was made by hand layup techniques and filled with equal proportions of SiO2 and MWCNT nanoparticles in different weight percentages, such as 0%, 1%, 2%, and 3%. The composites were made by using a symmetric stacking sequence of B/GG/BB/GG/BD/GG/B fibers. MWCNTs and SiO2 were evenly dispersed throughout the epoxy matrix with the assistance of an ultrasonicator and magnetic stirrer. The composite containing 2% fillers has an increased flexural strength by 20% from 307 to 378 MPa and flexural modulus by 30% from 11.181 to 15.901 Gpa, as well as an increased Charpy impact resistance by 45% from 236 to 418 J/m, compared with the composite without fillers. The interfacial interactions between the epoxy matrix, particles, and fibers significantly influenced the composite laminates’ flexural and impact characteristics. The accumulation of particles in the epoxy caused by the 3% fillers reduces the flexural strength and flexural modulus and impacts the performance due to the inadequate interfacial contact between the fibers and the epoxy matrix.

Novel Carbon Nanotubes/Gold Nanoparticles Modified Carbon Paste Electrochemical Sensor for Antazoline Determination in Aqueous Humor

Antazoline (ANT) is a H1 histamine receptor antagonist having anticholinergic properties used to decrease nasal congestion. It is found in eye drops usually in combination with either tetryzoline (TET) or xylometazoline (XLO). In this work, a novel electrochemical sensor based on carbon paste electrode (CPE) is developed for simple, rapid, sensitive, and selective determination of antazoline in pure form, different pharmaceutical formulations and in presence of aqueous humor. CPE is modified with nanoparticles multiwalled carbon nanotube (MWCNT) composite and further decorated with gold nanoparticles using amperometric electrodeposition technique to attain Au-NP@MWCNT/CPE for enhancing sensor sensitivity. Linearity is divided into two linear segments and found to be 2 × 10–7 − 2 × 10−6 (1st Linear segment) and 2 × 10–6 − 2 × 10−5 (2nd Linear segment) with limit of detection and quantification of 1.77 × 10−7 and 5.37 × 10−7, respectively. High sensitivity, selectivity, and reproducibility of the modified electrode towards determination of antazoline have promoted its applicability in different dosage forms and in rabbit aqueous humor. This method has noticeable potential applications in quality control, pharmacokinetic studies, and routine determination of antazoline drug in binary pharmaceutical formulations.

The effects of Multiwalled Carbon Nanotube to the performance of a refrigeration system

By incorporating nanofluid technology and nanolubricants into compressors, the performance can be enhanced while also lowering worldwide fuel consumption and aiming at developing cleaner, more efficient energy sources and uses. The globe is being confronted with energy security issues and heating, cooling and HVAC systems highly contribute to it. Hence, it is critical to save energy and improve the efficiency of the refrigeration cycle. This study presents experimental and theoretical findings in order to investigate the effect of Polyester (POE)-oil based multiwalled Carbon Nanotube (MWCNT) nanolubricant on the Coefficient of Performance (COP) of a refrigeration system. The objectives of this study is to analyze the stability of MWCNT nanofluids, to obtain the COP of a refrigeration cycle run with pure POE oil and MWCNT nanofluids with different concentrations respectively. The experiment was conducted by preparing 0.55, 0.65 and 0.70 g/l MWCNT nanofluid by using the two step method. The most effective concentration used in the refrigeration system was referred to the one that resulted in the highest COP. It was determined from the experiment that 0.55 g/l MWCNT nanofluid resulted in a higher COP of 5.766 as compared to the other two concentrations. Besides, it showed an improvement of 34.6% in COP as compared to the COP of using pure POE oil in the refrigeration system, which was found to be 4.285. The 0.65 g/l and 0.70 g/l concentration of MWCNT resulted in a COP of 5.618 and 5.617, respectively. The compressor work was also analyzed and was found to be reduced noticeably after adding MWCNT nanoparticles. Hence it can be concluded that the increment of MWCNT concentration in nanofluids increases the COP of the refrigeration system but only up to a certain limit of concentration.

Investigating the Impact of Carbon Nanotube Nanoparticle Exposure on Testicular Oxidative Stress and Histopathological Changes in Swiss albino Mice.

Carbon nanotubes (CNTs) possess remarkable properties that make them valuable for various industrial applications. However, concerns have arisen regarding their potential adverse health effects, particularly in occupational settings. The main aim of this research was to examine the effects of short-term exposure to multiwalled carbon nanotube nanoparticles (MWCNT-NPs) on testicular oxidative stress in Swiss albino mice, taking into account various factors such as dosage, duration of exposure, and particle size of MWCNT-NP. In this study, 20 mice were used and placed into six different groups randomly. Four of these groups comprised four repetitions each, while the two groups served as the vehicle control with two repetitions each. The experimental groups received MWCNT-NP treatment, whereas the control group remained untreated. The mice in the experimental groups were exposed to MWCNT-NP for either 7 days or 14 days. Through oral administration, the MWCNT-NP solution was introduced at two distinct dosages: 0.45 and 0.90 μg, whereas the control group was subjected to distilled water rather than the MWCNT-NP solution. The investigation evaluated primary oxidative balance indicators-glutathione (GSH) and glutathione disulfide (GSSG)-in response to MWCNT-NP exposure. Significantly, a noticeable reduction in GSH levels and a concurrent increase in GSSG concentrations were observed in comparison to the control group. To better understand and explore the assessment of the redox status, the Nernst equation was used to calculate the redox potential. Intriguingly, the calculated redox potential exhibited a negative value, signifying an imbalance in the oxidative state in the testes. These findings suggest that short-term exposure to MWCNT-NP can lead to the initiation of testicular oxidative stress and may disrupt the male reproductive system. This is evident from the alterations observed in the levels of GSH and GSSG, as well as the negative redox potential. The research offers significant insights into the reproductive effects of exposure to MWCNTs and emphasizes the necessity of assessing oxidative stress in nanomaterial toxicity studies.

Sandpack flooding of microwave absorbent nanofluids under electromagnetic radiation: an experimental study

AbstractElectromagnetic (EM) radiation has long been recognized as an effective method for enhancing the quality and recovery of heavy and extra-heavy crude oil. The incorporation of EM absorbers, particularly nanoparticles, has demonstrated significant potential to boost efficiency and expand the stimulated reservoir volume. However, the application of simultaneous EM radiation and nanofluid injection in a natural porous medium, which is critical for the successful implementation of this approach in field-scale operations, remains an underexplored frontier. In this context, this research represents a pioneering endeavor, aiming to bridge this knowledge gap through a comprehensive statistical and optimization study. The primary objective was to unravel the intricate interplay between five distinct types of magnetic nanoparticles and their concentrations within the base fluid to improve oil production. Notably, it focused on iron oxide (Fe3O4) magnetic nanoparticles and their innovative hybridization with multi-walled carbon nanotubes (MWCNT) and nickel oxide (NiO) nanomaterial. A newly designed glass sandpack was employed as the porous medium, thus mirroring real reservoir conditions more accurately. Then, a rigorous full factorial design scrutinized the multifaceted effects of nanoparticle type and concentration when introduced into deionized water during this process. The results showed that microwave radiation, applied at 400 W, dramatically improved oil recovery, catapulting it from a baseline of 19% to an impressive 39.5% during water injection. The addition of magnetic nanoparticles to the base fluid enhances efficiency. However, the specific type of nanoparticle exerts varying effects on oil recovery rates. Notably, the synthesis of Fe3O4–MWCNT nanoparticles had a substantial impact on the ultimate oil recovery factor, achieving approximately 69%. Furthermore, the hybridization of Fe3O4 nanoparticles with MWCNT and NiO nanoparticles leads to reduced consumption (using low weight percentages) while achieving the highest oil recovery rates during the injection process. Finally, the optimization analysis demonstrated that employing 0.34 wt.% of Fe3O4–MWCNT nanoparticles under 400 W of microwave radiation represents the optimal condition for achieving the highest oil production in a sandpack porous medium. Under these conditions, the oil recovery factor can increase to 78%.

Flexible piezoelectric sensor based on polyacrylonitrile/MWCNT/MXene composites films for human physiological health detection

AbstractFlexible piezoelectric sensors combine advantages including low‐cost, flexibility, multi‐functions, present a huge market prospect. In this research, multiwalled carbon nanotubes (MWCNT)/MXene/polyacrylonitrile (PAN) piezoelectric composites films for flexible piezoelectric sensors are fabricated by electrospinning technology, the planar zigzag conformation content of 97.98% in PAN composite fibers is achieved owing to the synergistic effect of MWCNT and MXene, the synergistic effect of MWCNT and MXene nanoparticles can also efficiently promote the mechanical performance and piezoelectric output. The piezoelectric sensor exhibits fast response time (10.21 ms), a possible mechanism is proposed to explain the improvement of piezoelectric effect. The sensor can measure human pulse, distinguish human movements, the fabricated sensor has broad practical value in the field of healthcare, its' use can contribute to stable and accurate measurements of physiological parameters, enabling applications in various healthcare and fitness monitoring scenarios.

Electrical properties of biodegradable chitosan-calcium phosphate nerve conduits doped with inorganic nanoparticles

Biodegradable nerve conductors are based on chitosan-calcium phosphate (CS/CaP) doped with nanoparticles of multiwalled carbon nanotubes (MWCNT+Fe), graphene oxide (GO), magnetite (Fe3O4) of various nanoparticle concentrations (NpC). Drug release and electrical properties were studied depending on the polarity, voltage, and electrode configuration (in-in, in-out), which reflect nerve regeneration inside the conduit and external electrical stimulation. The NpC of 150 μg/ml provides the highest electrical conductivity (EC) of 150MWCNT+Fe in-in. 150GO is more effective in the in-out configuration. The 300GO sample has an in-out electrical conductivity of 0.71∙ 10−2 S/cm, which is close to the natural nerve conductivity of 2.35∙10−2 S/cm. Nanoparticles in the CS/CaP matrix when interacting with the physiological solution ions can create new mechanisms for the current passage or neutralize existing ones. All samples are characterized by the absence of "burst drug release". Pregabalin (PG) release from Fe-containing samples is controlled by diffusion (first-order model), and from GO-containing – by diffusion and degradation of the matrix (second-order model).

Buckling analysis of sandwich plates reinforced with various loading of multi-walled carbon nanotubes

The current investigation aims to examine the buckling behavior of sandwich structures reinforced with faces containing varying weight percentages (wt.%) of multi-walled carbon nanotubes (MWCNT), through the combined employment of experimental and numerical analysis techniques. In particular, the numerical analysis is executed through the implementation of the generalized differential quadrature method (GDQM). The study first determines the mechanical properties of the pure and reinforced samples via experimental tests. The buckling equations of the sandwich plate are then derived using the Frostig approach and a high-order shear deformation theory (SDT) for the flexible core. The continuity conditions between the faces and the core are considered to obtain the structural equations of the system, and Lagrange coefficients are introduced to enhance the accuracy of the governing equations. Subsequently, the study investigates the impact of various parameters, such as core thickness, aspect ratio, different boundary conditions (BC), and the addition of MWCNT nanoparticles on the critical buckling load of the system, utilizing the mechanical properties obtained for the composite faces. The present investigation reveals that the incorporation of MWCNT into the composite matrix brings about notable enhancements in the mechanical characteristics of sandwich structures. Specifically, the elastic modulus and ultimate strength of the faces are found to increase following the addition of MWCNT. Additionally, the critical buckling load of the sandwich plates is observed to rise with an increase in aspect ratio and length-to-thickness ratio, while a decrease in axial load yields similar results. The clamped boundary condition has higher critical buckling loads than the simply supported boundary condition. The addition of MWCNT nanoparticles decreases the dimensionless critical buckling force as the b/a ratio increases. Finally, the reported results of the current investigation present noteworthy findings about the advancement and improvement of sandwich composite structures to meet various application requirements.

Effects of MWCNT nanoparticles injection points on incompressible laminar hydrogen flow through discrete phase modeling by CFD approach

Discrete phase model used in the aerospace industry to stimulate the behavior of particles inside the aircraft engines. The application of the discrete phase modeling (DPM) is extensive in solving the real-time engineering problems in optimization of numerous systems. In the current study, the DPM model has been simulated to examine the effect of injection point on the hydrogen flow field. A domain has been proposed and the injection point has been positioned in the four different places at the regular intervals. The location of the injection points was 0.2 m, 0.3 m, 0.4 m and 0.6 m. Dense discrete Eulerian lagrangian numerical simulation has been employed to analyze the effect of the multi-walled carbon nanotubes (MWCNT) nanoparticles. The hydrogen has been supplied at the injection velocity of 2 m/s. ANSYS implicit simulation setup has been tested across various injection points. The research found that the location of injection points plays a significant role in DPM concentration, with the highest concentration at 0.2 m and the lowest at 0.6 m, but has no significant impact on dynamic pressure. MWCNT nanoparticles had a negligible effect on skin friction coefficient, but shifting the injection point could reduce skin friction rates. The inclusion of MWCNT nanoparticles increased hydrogen flow velocity through downstream effects, vortices, and the nano-enhancement effect. The study suggests that MWCNT can significantly enhance hydrogen flow velocity in various applications, and DPM concentration data can provide valuable insights for optimizing injection locations to prevent unwanted nanoparticle effects.

Investigation on characteristics discrepancy through MWCNT nano particle blend of coconut oil

Due to their outstanding qualities, nanoparticles have proven effective in all engineering applications. The goal of the current work is to use the Multi walled Carbon Nano Tubes (MWCNT) to improve in engine performance and decrease in exhaust emissions caused by the addition of nanosized fuel additives to both diesel and blended diesel fuel. It has been discovered that adding gasoline additives improves combustion characteristics and promotes thermo-physical qualities. The fuel additive's addition accelerated burning and decreased the ignition delay. The ability to blend biodiesel with diesel was made possible by the enhancement of fuel characteristics brought about by nanoparticles used as fuel additives. It has been shown that adding the right amount of fuel additive improves ignition characteristics and decreases. In this investigation predominantly concentrated on characteristics discrepancy through MWCNT mixed blend of biodiesel of coconut oil (BCO). The biodiesel produced from the coconut oil through the transesterification procedure. For the improvement of the biodiesel properties by means of the involvement of the nano particles of MWCNT of size 30 to 40 nm. There are four combination of the nanoparticles added fuels such as were created to compare the properties. The variations were created with the amount of MWCNT mixing such as 50 ppm, 100 ppm, 150 ppm and 200 ppm in every liter of the fuel. BCO mixed with 200 ppm MWCNT mixed blend shows best performance as Calorific Value increased by 22.22%, Kinematic viscosity @ 40°C improved by 7.71%, percentage of Cetane number increased by 21.43%, The percentage of decreased the Carbon residue percentage by 7.67%, and the percentage of decreased Flash point by 8% than the base fuel BCO.

Wearable Piezoelectric Films Based on MWCNT-BaTiO3/PVDF Composites for Energy Harvesting, Sensing, and Localization

Polymer-based lead-free piezoelectric composites provide environmentally friendly and scalable space for energy conversion and structural health monitoring. In this paper, multi-walled carbon nanotubes (MWCNT)-BaTiO3/polyvinylidene fluoride (PVDF) piezoelectric composite films for energy harvesting, sensing, and localization were prepared. The highest β-phase content of 90.21% in PVDF composite nanofibers was achieved owing to the synergistic effect of MWCNT and BaTiO3 nanoparticles. The open-circuit voltage of the flexible piezoelectric nanogenerator based on interdigital electrodes reached 11.4 V at 2 Hz and a bending strain of 4 mm with an optimal power and power density of 8.67 μW and 1.16 μW/cm2, respectively, and can light up to 8 LED lights simultaneously. The output voltage did not decay during 1800 cycles, which met the power and stability requirements of a commercial capacitor. In addition, the prepared piezoelectric sensors exhibited anisotropy and high sensitivity. They had a maximum amplitude sensitivity of 93 dB, which was superior to the reported PVDF-TrFE sensors and suitable for low-frequency signal monitoring in the range of 20–40 kHz. Localization accuracy was greater than 90% in linear and planar localization tests, demonstrating the potential of preparing acoustic emission sensors. These properties facilitate the reduction of the quantity of sensors required to identify the source of damage.

Experimental investigation on a solar parabolic collector using water-based multi-walled carbon-nanotube with low volume concentrations

A limited experimental work was on multi-walled carbon nanotube (MWCNT)—water nanofluid with surfactant in the solar parabolic collector at low volume concentrations. At high-volume concentrated nanofluid, the pressure drop was more due to an increase in the viscosity of the working fluid and an increase in the nanoparticle cost; hence it is not economical. This report attempted to use Sodium Dodecyl Benzene Sulfonate (SDBS) surfactant in the low-volume concentrated MWCNT-water nanofluid to establish effective heat transfer in solar parabolic collector applications. The stable MWCNT-water nanofluid was prepared at 0.0158, 0.0238, and 0.0317 volume concentrations. The experiments were conducted from 10:00 to 16:00 at 6, 6.5 and 7 L/min flow rates concerning ASHRAE Standards. At the 7 L/min flow rate of the working fluid, having a minimum temperature difference between the working fluid and absorber tube leads to better heat transfer. The increased volume concentration of MWCNT in the water enhances the surface area interaction between water and MWCNT nanoparticles. This results in maximum solar parabolic collector efficiency at 0.0317 vol% with a 7 L/min flow rate and 10–11% higher than the distilled water.

Pore size variation of nano-porous material fixer on the engine bowl and its combined effects on hybrid nano-fuelled CI engine characteristics

Environmental research is currently one of the most significant and pertinent fields of studies. Due to CI engines'unique nature, theyare widely used in densely populated cities for a variety of purposes. However, due to their impropercombustion for various acceptable reasonsat the engine cylinder, they considerably pollute the environment. This study prepared hybrid nano fuel from waste cooking oil by adding Al2O3 (aluminum oxide) and MWCNT (multi-wall carbon nanotubes) particles and adding ZnO (zinc oxide) nanoporous material fixture in the combustion chamber as an attachment for enhancing combustion efficiency to meet the aim of mitigating the CI engine emissions significantly. The research was evaluated in a 5.2 kW CI engine, and the ZnO nano-porous material is fixed to the combustor. Four distinct pores per inch (PPI) nanoporous materials of pore counts such as 60, 45, 30, and 15 PPI were considered to test the fuels such as diesel and hybrid nanofuel. The hybrid nano-fuel was created from the WCO biodiesel by mixing nanoparticles of MWCNT and Al2O3 nanoparticles in the ultrasonicator. The experiments were carried out at different engine loads from no load to full load with a 25% step-up. The performance of the results was compared with conventional diesel fuel with and without ZnO nano-porous material fixtures and ZnO nano-porous material fixtures with different PPI. The result exhibited that the nanoparticles-added biodiesel fuel in 15 PPI has produced less NOx emission, CO emission, and heat release rate by 55.2%, 7%, 26.5%, and 22.67%, respectively, and this combination also exhibited an improvement of 2.62% in the brake thermal efficiency. Finally, the present work proves that better engine characteristics are generally obtained as the pore size of nanoporous materials in the engine bowl gets smaller, and the hybrid nanoparticles usage in the biodiesel fuel ensures more efficient engine combustion, performance, and emission characteristics.

Effect of nanoparticles mixing-ratio of Al2O3-MWCNT hybrid nano-cutting fluid during MQL turning

ABSTRACT Recent research has focused on replacing traditional cutting fluids with nano-cutting fluids to enhance machining performance. Also, hybrid nano-cutting fluid composed of two or more types of nano-particles has gained popularity. The aim of this study is to investigate the effect of the mixing ratio of Al2O3 (Alumina) and MWCNT (multiwall carbon nanotubes) nanoparticles blended in vegetable oil during the turning of stainless steel SS-304 with minimum quantity lubrication (MQL) cutting conditions. Two hybrid nano-cutting fluids with 1.5% weight concentration have been prepared using Al2O3 and MWCNT nanoparticles in the ratio of 80:20 and 60:40. The performance of hybrid nano-cutting fluids containing nanoparticles of both Al2O3 and MWCNT simultaneously has been compared with mono nano-cutting fluid containing only Al2O3 nanoparticles. Results show that use of hybrid nano-cutting fluid containing 20% and 40% MWCNT resulted in improvement in surface roughness of workpiece by 13.6% and 6.86%, respectively, over mono nano-cutting fluid.

Dielectric, electric, and piezoelectric properties of three‐phase piezoelectric composite based on castor‐oil polyurethane, lead zirconate titanate particles and multiwall carbon nanotubes

AbstractThe effects of multiwall carbon nanotubes (MWCNTs) on the electrical, dielectric, and piezoelectric properties of the ferroelectric ceramic/castor‐oil polyurethane (PUR) composite films were evaluated. The three‐phase piezoelectric composites were produced by keeping PUR concentration constant while varying lead zirconate titanate (PZT) volume fractions between 10 and 50 vol.%, at two MWCNT concentrations: above and below percolation threshold. Thedcelectrical conductivity analysis revealed that small amounts of MWCNTs dispersed within PUR/PZT composite films can significantly improve electrical and piezoelectric properties due to their ability to act as conductive bridges between PZT particles in the samples. Using Jonscher's power law, it was possible to determine that the electrical conduction inacregime occurs through spatial charge hopping between states located within the piezoelectric composite. Analyzing the piezoelectric properties through thed33coefficient, it was found that PUR‐MWCNT/PZT piezoelectric composite displayed higherd33values (20 pC/N) in comparison to the PUR/PZT two‐phase composite (9.5 pC/N) for all PZT loadings. According to these results, the dispersion of MWCNT nanoparticles influences the poling effectiveness of the PZT particles and increases thed33coefficient of three‐phase piezoelectric composites.