Amount Of Multi-walled Carbon Nanotubes Research Articles

Effect of incorporation of multi-walled carbon nanotubes on the CO2/CH4 separation performance of sulfonated poly (ether ether ketone) / polyetherimide composite membranes using design of experiments and molecular dynamics simulation methods

Blend membranes were prepared based on sulfonated poly (ether ether ketone) (SPEEK) and poly (etherimide) (PEI) using different amounts of multi-wall carbon nanotubes (MWCNTs) (up to 2 wt%). PEEK has been sulfonated directly to reach 70 % degree of sulfonation. The manufactured membranes were examined by X-ray diffraction (XRD), scanning field emission electron microscopy (FESEM), Fourier transformed infrared spectroscopy (FTIR). The effect of the composition of SPEEK / PEI on membrane selectivity was investigated under different feed pressures (2 to 8 bar) and temperatures (25 to 55 °C). The values of selectivity and gas permeability were varied between the value of the individual polymers, fluctuating systematically with SPEEK / PEI content variation in the blends. TGA and tensile tests result obtained for prepared membranes shown that the hybrid membrane had good thermal and mechanical properties. The addition of MWCNTs to the blend led to simultaneously improve the selectivity and permeability of the pair gases of CO2 and CH4. The permeability of CO2, as well as CH4/CO2 selectivity for the membrane with the same weight of SPEEK and PEI, and 1 wt% of MWCNTs (coded SP55M1) experienced an increase of about 22 % compared with the neat membrane. Molecular dynamics simulations (MDS) were performed by employing the COMPASS force field to estimate the diffusivity of CH4 and CO2 gases through selected membranes. At last, with compared to the obtained experimetal data, the optimized nanocomposite membrane, integrated with MWCNTs was efficient, which makes it promising platform to separate mixed gase flows of CO2 and CH4 and other related environmental processes.

Multi-walled carbon nanotubes decorated ZnMoO4 nanoflakes and their supercapacitive property

In this work, multi-walled carbon nanotubes decorated ZnMoO4 nanoflakes are synthesized by facile and rapid template-free hydrothermal approach. The prepared materials are characterized by various characteristic techniques. The synthesized materials are subjected as electrode materials for supercapacitive properties. The specific capacitance of 737 F g−1 is obtained at the current density of 1 A g−1 from ZnMoO4 nanoflakes. Further, the capacitance of prepared material is improved by doping a small amount of multiwall carbon nanotubes (MWCNTs). As a result, the specific capacitance of 1004 F g−1 is observed at 1 A g−1 from MWCNT/ZnMoO4 composite. The constancy of the prepared materials is performed up to 5000 cycles at 5 A g−1. Further, aqueous asymmetric supercapacitor is also designed by MWCNT/ZnMoO4 (as positive electrode) and activated carbon (AC) (as negative electrode). The high energy density of 28.61 W h kg−1 is calculated with power density of 725.52 W kg−1 from MWCNT/ZnMoO4//AC device. In addition, two yellow color LEDs are also powered by series connected two MWCNT/ZnMoO4//AC devices.

Enhancement effect of multiwalled carbon nanotubes on mortars prepared with different grades of recycled fine aggregates

Recycling construction waste while reducing natural sand mining has proven to be a sustainable option for environmental protection. Multiwalled Carbon nanotubes (MWCNTs) have the potential to enhance the mechanical characteristics of recycled fine aggregates (RFA) mortars. This research aims to explore the feasibility of applying MWCNTs in the RFA mortars. Various concentrations of MWCNTs were added to different grades of RFA-prepared mortar to obtain an optimal concentration. Besides, the scanning electron microscopy (SEM) analysis was conducted to observe the microstructure inside the RFA-prepared mortar. The nuclear magnetic resonance (NMR) test was used to test the pore structure of mortars. The results show that the RFA quality is relevant to the initial compressive strength of the RFA resource. The optimal concentration and the enhancement effect of MWCNTs on the three different RFA-prepared mortars are obtained with mechanical properties proven. The SEM images show that more cracks exist in the RFA-prepared mortars, and the NMR test shows that the number of pores inside the RFA-prepared mortars is significantly larger than that in the natural sand mortar. Nevertheless, an appropriate amount of MWCNTs can create a dense network and great bond inside the mortar, improving its mechanical properties.

Preparation and application of MWCNT-MoO3/ZnO ternary hybrid immobilized PVDF hybrid film photocatalyst

This study presents a novel method for immobilizing hybrid catalysts on polyvinylidene fluoride (PVDF) polymeric membranes for solid–liquid separation. A multi-walled carbon nanotube (MWCNT) doped with α-MoO3/ZnO photocatalyst (MWCNT-MoO3/ZnO) was prepared using an ultrasonic-assisted hydrothermal method. The photocatalysts were immobilized into PVDF membranes to prepare PVDF/MWCNT-MoO3/ZnO (IM-C3) via the phase inversion method and evaluated using methylene blue (MB) dye. The bandgap energy and e- - h+ separation potential of the materials was validated using UV–vis diffuse reflectance spectroscopy (UV–vis DRS) and photoluminescence (PL) spectroscopy. The UV–vis DRS results confirmed that the band gap energy of powdered photocatalysts decreased with increasing amounts of MWCNT as C1 (2.7 eV), C2 (2.6 eV), and C3 (2.4 eV). X-ray diffraction (XRD), and field emission scanning electron microscopy (FESEM) validate the structure and morphology of the photocatalysts. The EDX spectra confirm impurity-free samples. The Braeuer-Emmett-Teller (BET) method was used to determine the surface area (m2/g) and porosity of the MWCNT-MoO3/ZnO powdered photocatalyst, which exhibits a mainly mesoporous nature. The specific surface area of C3 was approximately 87.4 m2/g, which is greater than that of C2 and C1 (47.0 m2/g and 18 m2/g, respectively). The atomic force microscopy (AFM) and water contact analysis (WCA) showed that the surface roughness and hydrophilicity of the PVDF film were enhanced upon immobilization of the C3 photocatalyst. This resulted in a better interaction between the MB dye and the prepared IM-C3 hybrid film photocatalyst, thus making it capable of degrading 96 % of the MB dye within 120 min under visible light irradiation. The impact of the operating parameters of the hybrid film photocatalysts, such as the number of films, solution pH, MB concentration, radical scavenger, and recyclability studies, has been prioritized. The degradation percentage decreased as the initial concentration of MB (10–20 mg/L) increased but increased as the number of films increased. The superoxide radical (.O2–) and hydroxyl radical (OH.), were the dominant reactive species for the degradation of MB under visible light irradiation. The IM-C3 film can be reused up to five times without any kind of chemical treatment and without losing its stability or effectiveness.

Experimental thermal performance investigation of double pipe heat exchanger using MWCNT/water nanofluid

This paper presents an experimental study investigating the thermal performance of multiwall carbon nanotubes in a twin-pipe heat exchanger using a water-based fluid. The research followed a two-step method, where a concentration of 0.01 weight percent of SDS surfactant was utilized to prepare the carbon nanotubes. The heat transfer coefficient, friction coefficient, and overall heat transfer coefficient of the nanofluid were compared to those of the base fluid. The results revealed that the addition of a small amount of multiwall carbon nanotubes significantly enhanced the thermal conductivity and heat transfer coefficient of the water-based fluid. Moreover, the heat transfer coefficient exhibited an increase with higher Reynolds numbers. When the nanofluid flowed counter currently and was in the outer tube, the highest values for the overall heat transfer coefficient and the heat transfer coefficient were determined as 2864 and 7655.7 W/m2K, respectively. The findings indicate notable improvements in the thermophysical and thermal characteristics of the nanofluid.

Synthesis and photocatalytic performance of composite g-C3N4 with functionalized multi-walled carbon nanotubes

A novel g-C3N4 composite photocatalyst was synthesized by one-step calcination using melamine and different functionalized multi-walled carbon nanotubes (MWCNT) as raw materials. The effect of additives on the photocatalytic performance of the composite g-C3N4 has been investigated. The results showed that the incorporation of functionalized MWCNT led to a porous structure in g-C3N4, increasing the specific surface area and availability of active sites. The addition of hydroxylated/carboxylated MWCNT (HMWCNT/CMWCNT) affected the band structure of g-C3N4 and reduced the band gap. The visible-light photocatalytic degradation efficiency of Rhodamine B (RhB) using g-C3N4 composited with various types and amounts of MWCNT was evaluated. Among them, g-C3N4 with 1 wt% CMWCNT showed the highest photocatalytic degradation efficiency of RhB and still had 92.71% photocatalytic activity after 5 cycles of degradation.

Stability of the Photoluminescent Response on Hydroxyapatite/Multi-Walled Carbon Nanotube Composites

The application of hydroxyapatite (HAp)/multi-walled carbon nanotube composites in the medical area as coatings in prosthetics has been widely used because the carbon nanotubes reinforce the mechanical properties of hydroxyapatite. Despite that, their photoluminescent properties have not been studied, nor has the effect of different amounts of multi-walled carbon nanotubes on this property or what happened with their response with time. This work demonstrated that the photoluminescent response of HAp and HAp/multi-walled carbon nanotubes functionalized with oxygen groups (OMWCNT) composites was stabilized over time. The evaluated parameters were: three different amounts of OMWCNT (15, 25, and 35 mg) and two different thermal treatment temperatures (250 and 400 °C); all the samples were measured twice, after preparation and over a year after. The results indicated that over time the photoluminescent response is stabilized due to the passivation of surface defects, independently of the amount of OMWCNT used and the thermal treatment. In the end, the photoluminescent properties of these composites will extend their utilization in the medical area or open the door to new applications.

Electromechanical properties of multi-reinforced self-sensing cement-based mortar with MWCNTs, CFs, and PPs

This experimental research examines the electromechanical properties of hybrid cement-mortar composites strengthened with different amounts of multi-walled carbon nanotubes (MWCNTs), carbon fibers (CFs), and polypropylene microfibers (PPs). The experimental program included optimal mechanical improvement at the nano and micro levels. The optimum micro-composite mortar derives from the finest mechanical response of the CFs and PPs micro-modified specimens in terms of flexural and compressive strength. Further, the electrical response of the mortars with the improved mechanical response was examined. The improved mechanical and electromechanical response of the optimum amounts of the two scales indicates the hybrid mortar with exceptional performance. This optimum amount in micro-scale in synergy with the optimum amount of MWCNTs constituted the hybrid-reinforced cement-based mortar. The optimized nano-, micro-, and hybrid-reinforced mortars were examined for their electrical properties in terms of electrical conductivity, impedance, and piezo-resistivity. These measurements in combination with the Nyquist plots of the resistance-reactance specified the sensing ability of the cementitious self-sensor. Results indicated that the optimum reinforcement in the nanoscale is 0.2 wt% MWCNT and in microscale 0.5% wt.% CFs exhibited improvement in flexural strength, compressive strength, and flexural toughness. The optimum nano- and micro-reinforced cement-based mortars presented much higher conductivity of about 867% and 633%, and lower impedance of about 89.4% and 86%, respectively, compared to the reference specimen, and a one-order-of-magnitude compared to the other contents. The excellence of the hybrid combination of 0.2 wt% MWCNΤs and 0.5% wt.% CFs occur with even more improved flexural strength of about 27%, flexural toughness of about 1607%, conductivity of 2617% more than the reference mortar, and lower impedance of about 96%, compared to the reference specimen. The piezoresistive response of the tested cement-mortar composites denotes the enhanced strain-sensing ability of the examined multi-reinforced mortars, highlighting the superiority of the hybrid one.

Interlaminar Properties of Prepregs Reinforced with Multiwalled Carbon Nanotubes/Graphene Oxide.

Carbon-fiber-reinforced polymer (CFRP) composites are widely used in industries such as aerospace due to their lightweight nature and high strength. However, weak interfacial bonding strength is one of the main problems of resin-based composites. In this study, a prepreg was prepared by melt mixing. By dispersing nanoreinforcement particles in the resin, the interlaminar shear strength of the CFRP was increased by approximately 23.6%. When only 0.5 wt% multiwalled carbon nanotube (MWCNT) was used for reinforcement, scanning electron microscopy (SEM) micrographs showed that cracks were hindered by the MWCNTs during propagation, causing crack deflection. At the same time, the mechanism of MWCNTs pulling out increased the energy required for crack propagation. When only 0.5 wt% graphene oxide (GO) was added, the reinforcement effect was inferior to that of using the same amount of MWCNTs. The laminar structure formed by GO and the resin matrix adhered to the carbon fiber surface, reducing the degree of destruction of the resin matrix, but its hindering effect on crack propagation was weak. When 0.5 wt% of MWCNT and GO mixture was added, the interlayer shear strength increased from 55.6 MPa in the blank group to 68.7 MPa. The laminar structure of GO provided a platform for the MWCNTs to form a mesh structure inside its matrix. At the same time, the tubular structure of the MWCNTs inhibited the stacking of GO, providing better dispersion and forming a synergistic enhancement effect.

Multi-walled carbon nanotube decorated CoS microspheres and their supercapacitive properties

In the present work, microspheres of CoS are synthesized by most adoptable hydrothermal method. The synthesized material is figured out by numerous characteristic techniques. Further, the prepared CoS material is used as electrode material for supercapacitor and high specific capacity of 112.62 mAh g−1 is obtained at 1 A g−1. Furthermore, the capacity of sole product is boosted by adding a small amount of multi-walled carbon nanotubes (MWCNTs) and improved specific capacity of 158 mAh g−1 is obtained from MWCNT/CoS at 1 A g−1. Owing to high specific capacity of composite, aqueous asymmetric supercapacitor (ASC) is designed by MWCNT/CoS as a positive electrode and activated carbon (AC) as a negative electrode. The high energy density of 31.6 W h kg−1 is obtained at the power density of 750 Wh kg−1 from MWCNT/CoS//AC. In addition, two parallel connected red color LEDs, kitchen timer and a motor fan are functionalized by two MWCNT/CoS//AC devices.

Effects of MWCNTs on O2/N2 separation performance and morphology of sPEEK/PEI composite membranes: Experimental and molecular dynamics simulation studies

This study involved the development of blend membranes using sulfonated poly (ether ether ketone) (sPEEK) and poly (etherimide) (PEI) with varying amounts of multi-wall carbon nanotubes (MWCNTs) (up to 2 % by weight). The gas separation performance of these membranes was evaluated for the separation of O2 and N2 gases. In order to achieve a degree of sulfonation of 70 %, PEEK was sulfonated directly. The manufactured membranes were characterized using X-ray diffraction (XRD), scanning field emission electron microscopy (FESEM), Fourier transformed infrared spectroscopy (FTIR). Their operational evaluation was performed through permeability tests for pure gases of O2 and N2. The effect of sPEEK/PEI composition on membrane selectivity and gas permeability in the blend was studied. The selectivity and gas permeability values varied between those of individual polymers, fluctuating systematically with sPEEK/PEI content variation in the blends. The addition of MWCNTs to the blend improved the selectivity and permeability of O2 and N2 simultaneously. To further investigate the potential industrial application and stability of these membranes, experiments were conducted under different feed pressures (2 to 8 bar). The membrane containing 1 % of MWCNTs showed the best performance for O2 gas. Molecular dynamics simulations (MDS) were performed using the COMPASS force field to estimate the diffusivity of O2 and N2 gases through selected membrane systems. The simulated results agreed well with the available experimental data. With compared to the reported separating data, the prepared nanocomposite membrane was greatly efficient, which makes it promising platform to separate mixed gas flows and other related environmental processes.

Nanoindentation and nano-scratch testing on cement paste

Carbon nanotubes are an attractive reinforcement material for several composites. This is due to their inherently high tensile strength and high modulus of elasticity. This study focused on the nanomechanical characteristics of cement paste with and without short multi-walled carbon nanotubes (MWCNTs). The objective behind studying the nanomechanical properties of cement paste is to better understand the fundamental behaviour of cement at the nanoscale level. Cement paste is a complex material that consists of various phases, including cement hydrates, unhydrated cement particles and porosity. By studying the mechanical properties of cement paste at the nanoscale, researchers can gain insights into the mechanisms that govern the behaviour of this material. Following earlier tests, the amount of MWCNTs was kept constant (0.30% by weight of cement). The nanomechanical parameters explored included the localised Young's modulus and hardness. According to the test results, short MWCNTs increased the proportion of high-density calcium silicate hydrate in the cement paste. The nanomechanical properties (localised Young's modulus and hardness) of cement paste with short MWCNTs were found to be greater than those of cement paste without MWCNTs. According to nano-scratching experiments, the cement matrix with short MWCNTs was substantially more durable than the matrix without them.

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.

Low-voltage triggered electroactive and heat-responsive thermoplastic elastomer/carbon nanotube polymer blend composites

This study presents the synthesis and characterization of novel polymer composites that are triggered by heat and electricity. The composites were made of a blend of a styrenic block copolymer and a thermoplastic polyolefin elastomer, with multi-walled carbon nanotubes (MWCNTs) added as fillers. The composites were prepared through melt blending and the amount of MWCNTs was varied from 1 to 10 phr. The results of morphological characterization showed that the distribution of fillers within the matrix improved as the amount of MWCNTs increased. The crystallization temperature was also found to decrease due to the nucleation effect of the fillers. The reinforcing effect of MWCNTs resulted in increased values of elastic modulus, creep resistance, and storage modulus, while decreasing the values of elongation at break, creep recovery, and damping parameter (tanδ). The electrical resistance of the composites decreased with increasing amounts of MWCNTs, with the lowest resistance recorded in the composite which contains 10 phr MWCNT (10CNT) composite at 12 ohm.cm. The 10CNT composite was also able to be heated up to 75 °C by Joule heating at a voltage of 5.5 V. The shape fixing performance of the blend improved in the presence of fillers, however, despite an increase in the recovery stress value, the heat-responsive shape recovery feature worsened. The composite having 5 phr MWCNT (5CNT) showed electro-active shape recovery under 25 V in 210 s, while the 10CNT composite completed this process in 300 s under 5.5 V. The results of this study demonstrate the potential of using MWCNTs as fillers in polymer composites for various applications that require both electrical conductivity and heat responsiveness.

Two-step method to realize continuous multi-wall carbon nanotube grafted on the fibers to improve the interface of carbon fibers/epoxy resin composites based on the Diels-Alder reaction

A new simple and continuous method was developed for chemically grafting multi-wall carbon nanotubes (MWCNTs) onto the surface of carbon fibers (CF) to improve the interlaminar properties of composites. In this method, maleimide-grafted waterborne polyurethane emulsion and furan functionalized MWCNTs were prepared. Then, based on the Diels-Alder reaction under mild reaction conditions (60 °C), CF/MWCNTs multi-scale reinforcements (MSCF) were successfully prepared through a two-step method of MWPU sizing and MWCNTs ultrasonic grafting, which overcame the complex process flow, greatly shortened the preparation time and avoided damage to fibers. The successful grafting of MWCNTs was proved by the results of SEM and HRTEM. After grafting MWCNTs, the interface between the matrix and fibers was enhanced. The interlaminar shear strength (ILSS) and flexural strength of MSCF/epoxy reinforced composites were promoted to 64.54 MPa and 981.95 MPa, which was prominently increased by 52.84% and 32.32%, respectively. In addition, this process could match the current production of carbon fibers for commercialization, but further research was expected to control the grafting amount of MWCNTs and their impact on performance.

Near‐Room‐Temperature Thermoelectric Performance Enhancement Via Phonon Spectra Mismatch in Mg3(Sb, Bi)2‐Based Material by Incorporating Multi‐Walled Carbon Nanotubes

AbstractAlthough a high figure of merit (zT) over a wide range of temperatures has been shown in n‐type Zintl Mg3(Sb, Bi)2, further improvement of its near‐room‐temperature performance is still required to promote its application in next‐generation thermoelectric coolers and power generators. Here, a novel strategy of phonon spectra mismatch for enhancing the thermoelectric performance of Mg3(Sb, Bi)2 is reported by incorporating multi‐walled carbon nanotubes (MWCNT). The introduction of very small amounts of MWCNT generates a large interfacial thermal resistance and thus significantly reduces the lattice thermal conductivity of the resulting composites, while maintaining a high power factor. As a result, a zT of ≈1.5 at 573 K and an average zT of 1.14 between 323 and 573 K can be achieved in the 0.5 wt% MWCNT composite. Moreover, a high conversion efficiency of ≈8.1% under a temperature difference of 283 K is realized in a resulting single‐leg device, making it a promising candidate material for low‐grade heat recovery. This study provides not only a material with a high near‐room‐temperature zT but also a unique insight into the design of high‐performance thermoelectric materials via compositing to exploit the large difference in phonon spectra between the components of the composite.

Flexural and flame retardance properties of multi-walled carbon nanotubes/glass fibre/epoxy hybrid composites

The effect of different multi-walled carbon nanotubes (MWCNTs) wt.% loading on the flammability, water absorption, thermal stability and flexural properties of glass fabric reinforced epoxy composites is reported in this paper. The pristine MWCNTs were dispersed in water, using arabic gum (GA) as a dispersing agent. Then, the suspension was sprayed onto the glass fibre (GF). Hybrid composites with and without MWCNTs were fabricated using hand lay-up and vacuum bagging techniques. Based on standard fire testings such as limiting oxygen index (LOI) and horizontal burning (UL94HB), it was observed that the composites were able to self-extinguish, even at low amounts of MWCNTs. Increase in the MWCNTs content produced a concurrent increase in the LOI of the composites which reached a maximum value of 31.30 ± 1.22% at 1 wt% MWCNT. The thermal stability was investigated using thermogravimetric analysis (TGA) and it was found that the addition of MWCNTs improved thermal stability, and increased the fire-retardance of the glass fabric reinforced epoxy (GF/EP) composites. The highest composite flexural strength (150 MPa) and flexural modulus (12 GPa) were attained at 0.5 wt% MWCNT. Above 0.5 wt%, a drop in strength and modulus was observed. The results from this study showed that the use of hybrid reinforcement containing MWCNTs can help to significantly improve the flame retardance, water absorption, and mechanical properties of reinforced composites by incorporating optimum amount of MWCNTs.

PLA/MWCNT Nanocomposite: Improved Electrical, Thermal and Antibacterial Properties for Fused Deposition Modelling Additive Manufacturing Applications

Incorporation of nanoparticles in Polylactic Acid (PLA) for additive manufacturing is explored to alter the material property to suit its intended application. In this study, PLA is reinforced with multi-walled carbon nanotubes (MWCNT) using two-roll mill for fused deposition modeling (FDM) additive manufacturing. The chemical composition, thermal behavior, electrical, and antibacterial properties of the PLA/MWCNT nanocomposite were investigated. The Fourier transform infrared spectroscopy (FTIR) analysis showed the physical interaction of MWCNT to the PLA matrix. The x-ray diffraction analysis (XRD) data showed that increasing the MWCNT percentage increases the amorphous region and intensity, indicating the nucleating effect of MWCNT on PLA. Differential scanning calorimetry (DSC) analysis showed a decrease in the glass transition and melting temperatures compared to pure PLA by up to 9.36°C and 23.25°C, respectively, while introducing cold crystallization with the addition of MWCNT. The two point-probe resistance measurement showed a decreasing trend in the resistance of the composite which indicates an increase in conductivity as the the amount of MWCNT is increased. The analysis of disk diffusion test concluded that no bacterial growth of Escherichia coli and Staphylococcus aureus happened underneath the sample. Furthermore, the nanocomposite was successfuly extruded into a filament and test samples were 3D printed using FDM. The PLA/MWCNT produced are suitable for the production of a multifunctional filament with improved electrical, thermal and antimicrobial properties for different fused deposition modelling (FDM) additive manufacturing increasing the probable applications and competitiveness of this promising market niche.

Impact of Proton Irradiation on Medium Density Polyethylene/Carbon Nanocomposites for Space Shielding Applications.

The development of novel materials with improved radiation shielding capability is a fundamental step towards the optimization of passive radiation countermeasures. Polyethylene (PE) nanocomposites filled with carbon nanotubes (CNT) or graphene nanoplatelets (GNP) can be a good compromise for maintaining the radiation shielding properties of the hydrogen-rich polymer while endowing the material with multifunctional properties. In this work, nanocomposite materials based on medium-density polyethylene (MDPE) loaded with different amounts of multi-walled carbon nanotubes (MWCNT), GNPs, and hybrid MWCNT/GNP nanofillers were fabricated, and their properties were examined before and after proton exposure. The effects of irradiation were evaluated in terms of modifications in the chemical and physical structure, wettability, and surface morphology of the nanocomposites. The aim of this work was to define and compare the MDPE-based nanocomposite behavior under proton irradiation in order to establish the best system for applications as space shielding materials.

Piezoresistive response of carbon nanotube and carbon fiber/epoxy composites under cyclic loading

Maintaining the mechanical properties and long-term operational safety is considered the main challenge for composite materials under cyclic loading. This work presents mechanical performance of tri-component composites based on multiwall carbon nanotubes (MWCNTs), carbon fibres (CFs) and epoxy resin, and their electrical conductance property for applications like strain gauges. As a result of incorporation of MWCNTs into the epoxy resin in the composite’s morphology, their electrical, mechanical and piezoresistive performance can indicate the self-sensing of carbon fiber reinforced epoxy resin matrix (CF/Epoxy matrix) composites; and thus its influence has been systematically examined. The inclusion of multiwall carbon nanotubes increased the resin bonding to the surface of the CF’s leading to an increased electrical conductivity and mechanical performances. The piezoresistive performance was significantly influenced by the amount of MWCNTs added to the resin, where the Gauge Factor (GF) with respect to the MWCNTs concentration under cyclic tensile and cyclic bending were in the range of 0.6∼1.5 and 2.5∼5.5 respectively. Moreover, the piezoresistive behaviour of the composite samples showed reasonable sensitivity, stability, and reversibility under cyclic mechanical loading, and the samples withstood more than 500 cycles of load without detectable loss in performance. The exceptional mechanical, electrical and piezoresistive performance and easy manufacturing process of the tri-component composites make them attractive for applications such as self-monitoring structural components.