Final Composites Research Articles

Compounds based on iron mining tailing dams and activated carbon from macauba palm for removal of emerging contaminants and phosphate from aqueous systems.

In this work, an iron-rich residue, which is widely obtained as a by-product in the iron mining industry, and macauba endocarp, waste from the extraction of vegetable oil for the production of biofuels, were used in the preparation of different composites based on iron and carbon. The composites were obtained by manual grinding of the calcined iron residue and activated carbon prepared by the macauba endocarp followed by thermal treatment under nitrogen atmosphere. The effect of the thermal treatment was analyzed by Mössbauer spectroscopy and X-ray diffraction and showed that the increase in the treatment temperature promoted the formation of different reduced iron phases in the final composite, such as Fe3O4, FeO, and Fe0. These composites were used in a combined adsorption/oxidation process through photocatalysis to remove up to 93% of amoxicillin from aqueous phase. The formation of possible reaction intermediates was monitored by electrospray ionization mass spectrometry (ESI-MS) and a mechanism of amoxicillin degradation was proposed. Afterward, the Fe/C composites were conducted to evaluate the impact of several parameters on phosphate adsorption processes and showed a maximum adsorption capacity of 40.3mgg-1. The adsorption capacity obtained for all the materials were greater than those found in the literature.

Synthesis of cardanol grafted hydrophilic polymers and its mechanism of coal dust inhibition

A novel hygroscopic sodium cardanol polyoxyethylene ether sulfate (SCPES) dust suppressant was synthesized via graft copolymerization, sulfonation, and alkalization reactions of cardanol and polyoxyethylene. The critical micelle concentration, chemical synthesis and wetting mechanism of SCPES were investigated using pyrene fluorescence spectroscopy, Fourier transform infrared spectroscopy, quantum chemistry and molecular dynamics software. SCPES was synthesized in three steps: first, the phenolic –OH of cardanol was de-H and grafted with polyoxyethylene to form cardanol polyoxyethylene ether (CPE); second, the H atom of CPE was replaced by the –SO3H of H2SO4 to generate cardanol polyoxyethylene ether sulfate (CPES); finally, the H+ of CPES was alkalized with the OH− of NaOH to form SCPES. It was found that the active centers of the three reactions were all at the O–H bond, the activation energies were 233.66, 85.99, and − 66.91 KJ/mol, and the final composite had distinct aromatic ether (Ar–O, R–O), S–O, and S = O infrared absorption peaks, proving that SCPES had been successfully prepared. 0.10 g/L and 0.25 g/L were the critical association concentration and critical micelle concentration of SCPES, and the surface tension and contact angle at the critical micelle concentration were 33.12 mN/m and 39.5°. Compared with the H2O-lignite system, the H2O-SCPES-lignite system exhibited an increase in the total number of hydrogen bonds from 2082 to 2136, a decrease in the interaction energies from − 13863.35 kcal/mol to − 17817.77 kcal/mol, and an increase in the diffusion coefficients of H2O molecules from 0.12 to 0.73. The results indicated that the long hydrophobic tail chain in the molecular structure of SCPES was entangled with the hydrophobic sites on the coal surface, acting as intermediate carriers between water and coal to improve the wettability of coal dust, and providing a new technical means for coal dust inhibition.

“Application of the DoE approach to the fabrication of cast Al2O3-LM6 composite material and evaluation of its mechanical and microstructural properties”

This paper explain the impact of varying amount of reinforcement on mechanical and micro-structural properties during the fabrication of Al2O3-LM6 cast composite at self-pouring temperature. To decide the reinforcement proportion, use of mixture design of approach was used. Fine triturates of Al, Si, and xAl2O3 (x = 2%, 3%, and 4%) were mixed firstly by using ball milling. Then powder mix, which was pre-heated and became moisture free, condensed in sealed steel die. Compacted pre-forms were heated in a muffle furnace in the presence of Argon gas which creates an inert environment at self-poring temperature deprived of forming liquid slurry to pour under gravity in the cavity of Plaster of Paris (POP) die to synthesize the final cast composite. Blend combination was decided using mixture Design of Experiment (DOE) through Minitab Software and an Analysis of Variance (ANOVA) was performed to heighten the best mixture combination. Then fabricated modified cast composite then tested to show a combined outcome of reinforcement proportion on modified physical, mechanical and micro-structural properties.

Cement-Based Composites Containing Oxidized Graphene Nanoplatelets: Effects on the Mechanical and Electrical Properties.

Graphene nanoplatelets can improve the electrical and mechanical properties of cement matrix composites. The dispersion and interaction of graphene in the cement matrix appears to be difficult due to its hydrophobic nature. By introducing polar groups, graphene oxidation improves the level of dispersion and interaction with the cement. In this work, graphene oxidation using sulfonitric acid for 10, 20, 40, and 60 min was studied. Thermogravimetric Analysis (TGA) and Raman spectroscopy were employed to analyze the graphene before and after the oxidation. The mechanical properties of the final composites showed an improvement of 52% in the flexural strength, 4% in the fracture energy, and 8% in the compressive strength in the case of 60 min of oxidation. In addition, the samples showed a reduction of at least one order of magnitude in electrical resistivity when compared with pure cement.

Stabilization of Palladium-Nanoparticle-Decorated Postsynthesis-Modified Zr-UiO-66 MOF as a Reusable Heterogeneous Catalyst in C-C Coupling Reaction.

Here we prepared a highly efficient and reusable catalyst by a step-by-step postsynthesis modification of UiO-66-NH2 metal-organic frameworks (MOFs) with nitrogen-rich organic ligands and used it as support for the preparation of UiO-66-NH2@cyanuric chloride@2-aminopyrimidine/PdNPs. The catalytic performance's results of UiO-66-NH2@cyanuric chloride@2-aminopyrimidine/PdNPs, UiO-66-NH2/PdNPs, and UiO-66-NH2@cyanuric chloride/PdNPs indicate high efficiency of the modulation of the microenvironment of the palladium NPs. The addition of N-rich organic ligands through postsynthesis modification caused a unique structure of the final composite in favor of the progress of the C-C coupling reaction. Various techniques, including FT-IR, XRD, SEM, TEM, EDS, and elemental mapping, were used to characterize UiO-66-NH2@cyanuric chloride@2-aminopyrimidine/PdNPs, indicating its successful preparation. Three C-C coupling reactions, including the Suzuki, Heck, and Sonogashira coupling reactions, were promoted using the produced catalyst. As a result of the postsynthesis modification (PSM), the proposed catalyst displays improved catalytic performance. In addition, the suggested catalyst was highly recyclable up to ten times without leaching of PdNPs.

Interface Characterization of Consolidated PPGF Tapes on PPGF Mat Material.

Laminated composites with thermoset matrices are already well established in major engineering fields like automotive and aviation. The primary drawbacks of such thermoset-based composites are the high cycle times required during manufacturing and their limited potential for recycling. Providing an alternative to thermoset-based composites, thermoplastic matrix materials gained more and more momentum by addressing these previously mentioned drawbacks. The preferred manufacturing technique for these materials employs fiber-reinforced thermoplastic tapes consolidated and formed together with a compatible substrate. The most critical aspect for all these applications is the stress or load transfer between the thermoplastic tapes and the substrate. If the interface is too weak and fails prior to the substrate or tape, a high amount of theoretical mechanical performance is lost. The presented research investigates the influence of variations in manufacturing parameters, within the industrially relevant process window, on the interface strength of the final composite. The investigated composite material consists of PPGF UD tapes consolidated on a PPGF mat substrate. In particular, the influence of the consolidation parameters of pressure, temperature, and time are of special interest. The results of this work reveal a 400% increase in the measured mean strain energy release rate upon increasing the consolidation time from 60 s to 120 s at a consolidation temperature of 230 °C and a pressure of one bar. In contrast to this, an increase in the consolidation pressure, at constant temperature and time, leads to a minor improvement in the GC value of 20%. For testing and characterizing the corresponding interface properties, a mandrel peel testing setup was employed.

Synergistic association of wood /hemp fibers reinforcements on mechanical, physical and thermal properties of polypropylene-based hybrid composites

Natural fiber-reinforced composites with thermoplastic matrices are gaining prominence in society as their applications are found in varied industries, e.g., automotive and aerospace. A recent trend shows the use of hemp fibers as reinforcements for the manufacture of bio-based composites, which are thermally and dimensionally stable, and durable. In this work, polypropylene (PP) was reinforced with 5, 10, 20, 30, and 40 wt% hemp fibers, having undergone an alkaline treatment, were processed, and investigated. Results showed that the composites made of hemp fibers with PP have exhibited good mechanical properties. A value of 2.12 GPa for young's modulus is achieved from a biocomposites containing 30 wt% of hemp fibers which is significantly higher than the 0.85 GPa of PP matrix. The full potential of hemp fibers as reinforcement for the PP matrix is demonstrated by this maximum, which represents a rise of 149% for the young's modulus and 40% for the tensile strength. Flexural modulus increased of 46%, 165%, and 232% compared to virgin PP at 10, 30, and 40 wt% fiber content. Such stiffness increases were followed by flexural strength increases of 52%, 78%, and 92% relative to virgin PP in the presence of 20, 30, and 40 wt% hemp fibers, respectively. A study was also conducted to evaluate the effects of various parameters on the thermo-mechanical properties of the final composites, which were hybrids made of PP reinforced with both hemp fibers and wood flour. These hybrid bio-composites prepared with 20 and 40 wt% hemp fibers and wood flour and variable ratios of the two reinforcements showed a positive hybridization effect. Nevertheless, the modulus of the hybrid biocomposites reinforced by both fibers, hemp/Wood floor (20/20), is 166% greater than the modulus of unreinforced PP and 34% greater than the Hemp/PP composite with 40% fiber content. Finally, a comparative study shows that the newly formulated hybrid composite has the potential to replace various existing natural fiber-reinforced composites. This study's approach is, although we know, unique.

Preparation, Characterization, and Wound Healing Assessment of Curcumin-Loaded M-MOF (M = Cu, Zn)@Polycaprolactone Nanocomposite Sponges.

The fabrication of multifunctional scaffolds has attracted much attention in biological fields. In this research, some novel composites of Cu(II) or Zn(II) metal-organic framework (M-MOF) and polycaprolactone (PCL), M-MOF@PCL, have been fabricated as multifunctional scaffolds for application in the tissue engineering (TE) field. The porous three-dimensional sponges were prepared by the salt leaching method. Then, the M-MOF@PCL composite sponges have been prepared by in situ synthesis of M-MOF in the presence of the as-obtained PCL sponge to gain a new compound with proper features for biological applications. Finally, curcumin was attached to the M-MOF@PCL as a bioactive compound that can act as a wound-healing agent, anti-oxidant, and anti-inflammatory. The presence of the M-MOF in final composites was investigated by different methods such as FTIR (Fourier-transform infrared), XRD (X-ray diffraction), SEM (scanning electron microscope), EDS (energy-dispersive X-ray spectroscopy), and TEM (transmission electron microscope). SEM images confirmed the porous structure of the as-obtained composites. According to the EDS and TEM images, M-MOFs were uniformly incorporated throughout the PCL sponges. The water sorption capacities of the blank PCL, Cu-MOF@PCL, and Zn-MOF@PCL were determined as 56%, 155%, and 119%, respectively. In vivo investigation on a third-degree burn model in adult male Wistar rats exhibited an accelerated wound healing for Cu-MOF@PCL compared to with Zn-MOF@PCL and the control group.

Flexible and Stretchable Elastomer Composites Based on Lightweight Liquid Metal Foam Spheres with Pod-like Contacts

Liquid metal (LM) is increasingly employed as a conductive filler in soft and flexible elastomer composites owing to its favorable conductivity and liquid fluidity. However, the high density of LM inevitably increases the weight of composites, which brings limitations in large-area and weight-sensitive applications. This work reports a flexible and stretchable elastomer composite composed of pod-like contacting lightweight LM foam spheres and polydimethylsiloxane matrix (LMS/PDMS). The lightweight LMS reduces the amount of LM used in the preparation process while imparting good electrical conductivity and deformability to the composite. The different contact modes of LMS endow the final composites with diverse strain sensitivity. The mechanism of interfacial contact conduction between the LMS with different melting points has been systematically studied, and the result shows that the liquid-solid contact mode of LMS further improves the strain sensitivity of the composite. Moreover, the composite also has satisfactory electrothermal properties and the temperature can quickly reach 70 °C within 30 s, showing good applicability in electric heating. Finally, the composites containing LMS with different contact modes can be developed as multifunctional sensors to detect human activities, temperature variation, and even underwater vibration, demonstrating the great potential in next-generation sensors and electronics.

Effect of type of mixer on rheological and mechanical behavior of ultra high‐performance concrete

AbstractUltrahigh‐performance concrete (UHPC) is becoming increasingly frequent in several civil construction projects such as industries, buildings, and even infrastructure. The rheological and mechanical behaviors, coupled with durability, are the driving motives for this increase in use over the last few decades. However, the type of mixer used in UHPC production considerably affects the final composites performance due to variations in mixing velocity and the need to disperse particles with low granulometry. This study evaluated the effect of type of mixer in the properties of UHPC in the fresh and hardened states. This study evaluates three types of mixers: planetary vertical axis, horizontal axis, and drum. Results showed that the drum mixer was the least efficient in homogenizing the composite. It showed an average mixing time about 126% longer than planetary vertical or horizontal‐axis mixers to reach the same level of flowability. The composite from the drum mixer also had the most entrained air and void index. The planetary vertical‐axis mixer was the most efficient, with the resulting composite having a potential compression strength of 169.1 MPa, 19.3% higher than the composite from the horizontal‐axis mixer.

Investigating the Synthesis and Characteristics of UV-Cured Bio-Based Epoxy Vegetable Oil-Lignin Composites Mediated by Structure-Directing Agents.

Bio-based composites were developed from the epoxy derivatives of Lallemantia iberica oil and kraft lignin (ELALO and EpLnK), using UV radiation as a low energy consumption tool for the oxiranes reaction. To avoid the filler sedimentation or its inhomogeneous distribution in the oil matrix, different structure-directing agents (SDA) were employed: 1,3:2,4-dibenzylidene-D-sorbitol (DBS), 12-hydroxystearic acid (HSA) and sorbitan monostearate (Span 60). The SDA and EpLnK effect upon the ELALO-based formulations, their curing reaction and the performance of the resulting materials were investigated. Fourier-transform Infrared Spectrometry (FTIR) indicates different modes of molecular arrangement through H bonds for the initial ELALO-SDA or ELALO-SDA-EpLnK systems, also confirming the epoxy group's reaction through the cationic mechanism for the final composites. Gel fraction measurements validate the significant conversion of the epoxides for those materials containing SDAs or 1% EpLnK; an increased EpLnK amount (5%), with or without SDA addition, conduced to an inefficient polymerization process, with the UV radiation being partially absorbed by the filler. Thermo-gravimetric and dynamic-mechanical analyses (TGA and DMA) revealed good properties for the ELALO-based materials. By loading 1% EpLnK, the thermal stability was improved to with 10 °C (for Td3%) and the addition of each SDA differently influenced the Tg values but also gave differences in the glassy and rubbery states when the storage moduli were interrogated, depending on their chemical structures. Water affinity and morphological studies were also carried out.

On the Influence of Flame-Retardant Additives on UV-Curable Thermosetting Glass Fiber-Reinforced Composites.

One of the main advantages of fiber-reinforced polymer (FRP) composites is the ability to reduce their weight while they exhibit exceptional properties such as high strength, stiffness, and resistance to corrosion, and reduction in their lifetime maintenance when they are compared to the metallic components. These features led fiber-reinforced polymer composites to have applications in the mechanical, construction, aerospace, automotive, medical, marine, and other manufacturing industries. However, the use of this type of material is not possible in all of these applications since, in certain sectors, the fire resistance property that the material must present is one of the key factors. For this reason, a thermosetting resin composed of ultraviolet (UV)-curable acrylic monomers has been used as a matrix, where transparent aluminum trihydrate (ATH) flame-retardant fillers were incorporated for manufacturing flame-retarded UV-curable composites. The composite parts were produced by using glass fiber-reinforced UV-curable prepregs. An exhaustive study of different types of ATH-based flame-retardant additives and the possible cooperation between them to improve the fire properties of the UV-curable composite was carried out. Additionally, the most suitable additive percentage to meet the railway sector requirements was also evaluated, as well as the evolution in the viscosity of the matrix and its processing capacity during the manufacture of the prepregs at 60 °C. The compatibility between the fillers and the matrix was assessed using a dielectric analysis (DEA). The fire properties of both the matrix and the final composite were established.

Numerical Study on the Resin Transfer Molding Curing Process for Thick Composites Materials

The successful manufacture of thick composites is challenging since the highly exothermic nature of thermoset resins and limited temperature control make avoiding the onset of detrimental thermal gradients within the composite relatively difficult. This phenomenon is mainly caused by exothermic heat reactions. The so-called Michaud's model has been largely used in the literature to reduce the gap between experience and simulation with regard to the effective prediction of the temperature cycle in these processes. In this work, another solution is proposed to simulate the curing process for thick composites, namely preheating the resin to activate the curing reaction before resin injection into the mold. A good agreement between the experiment and the simulation is found. Moreover, in order to minimize the thermal gradient in the final composite, the thermophysical properties of the fiber and the torque (temperature, time) of the Plate have been varied leading to interesting results.

Stabilization of copper nanoparticles onto the double Schiff-base-functionalized ZSM-5 for A3 coupling reaction catalysis aimed under mild conditions.

In this research a highly efficient and heterogeneous catalyst of ZSM-5@APTMS@(E)-4-((pyridin-2-ylimino)methyl) benzaldehyde@Cu-NPs was synthesized for upgrading the A3 coupling reaction for the synthesis of propargylamines under mild conditions. Rational tuning of the microenvironment of metallic NPs to improve efficiency and reusability in catalytic performances is of significance for scalable applications. Firstly, ZSM-5 was immobilized with APTMS (3-aminopropyltrimethoxysilane) and further modified with (E)-4-((pyridin-2-ylimino)methyl)benzaldehyde. Subsequently, the amine-activated zeolite@(E)-4-((pyridin-2-ylimino)methyl)benzaldehyde was applied to increase the stabilization of Cu metal nanoparticles. The catalyst was treated with hydrazine to reduce Cu(ii) to Cu(0), which led to active metal sites. The results of catalytic performance in comparison with different parts of catalysis indicate high efficiency due to the stabilization of copper nanoparticles onto the newly synthesized support of MOF modified with nitrogen aromatic groups. The addition of N-rich organic ligand through modification alters the electronic structure of the final composite in favor of the progress of the A3-coupling reaction. Moreover, the proposed catalyst showed no reduction in the catalytic performance up to four cycles, and a minor loss of efficiency occurs after the seventh cycle. In addition, the catalyst was effectively recycled up to 7 times without leaching of Cu-NPs.

Synthesis and Characterization of Graphene Oxide and Chitosan Decorated Nano Zerovalent Iron for Efficient Adsorptive Removal of Hazardous Azo Dye from Aqueous Medium

The main aim of the study was to synthesize nano zerovalent iron (NZVI) modified with graphene oxide (GO) and chitosan (CS) in the form of a magnetic ternary nanocomposite. Three ternary nanocomposites i.e. GO-CS-NZVI, GO-NZVI-CS and CS-NZVI-GO were synthesized to further understand the possible binding tendencies among these components in the final ternary composite. These ternary composites were characterized by FTIR, SEM and EDS techniques to understand the effect of mutual interaction of the three components during synthesis on the overall structure and morphology of the ternary composite. Furthermore, these ternary nanocomposites were employed in the removal of Congo red (an anionic, carcinogenic, azo dye) and also a mixture of dyes Congo red and Rhodamine B (a cationic, carcinogenic dye). A maximum of 98% removal of Congo red and 98.7% removal from the mixture of dyes was observed with ternary nanocomposite GO-CS-NZVI within 30 min. Equilibrium adsorption efficiency (qe) was calculated to be 48.15 and 79 mg/g for Congo red and mixture of dyes (Congo red & Rhodamine B), respectively. A comparative analysis of bare NZVI with these ternary nanocomposites was also conducted to further understand the effect of modification of NZVI with graphene oxide and chitosan on the structure, morphology and its dye removal efficiency.

Characterization of Ag-Ion Releasing Zeolite Filled 3D Printed Resins.

There has been profound growth in the use of 3D printed materials in dentistry in general, including orthodontics. The opportunity to impart antimicrobial properties to 3D printed parts from existing resins requires the capability of forming a stable colloid incorporating antimicrobial fillers. The objective of this research was to characterize a colloid consisting of a 3D printable resin mixed with Ag-ion releasing zeolites and fumed silica to create 3D printed parts with antiviral properties. The final composite was tested for antiviral properties against SARS-CoV-2 and HIV-1. Antiviral activity was measured in terms of the half-life of SARS-CoV-2 and HIV-1 on the composite surface. The inclusion of the zeolite did not interfere with the kinetics measured on the surface of the ATR crystal. While the depth of cure, measured following ISO4049 guidelines, was reduced from 3.8 mm to 1.4 mm in 5 s, this greatly exceeded the resolution required for 3D printing. The colloid was stable for at least 6 months and the rheological behavior was dependent upon the fumed silica loading. The inclusion of zeolites and fumed silica significantly increased the flexural strength of the composite as measured by a 3 point bend test. The composite released approximately 2500 μg/L of silver ion per gram of composite as determined by potentiometry. There was a significant reduction of the average half-life of SARS-CoV-2 (1.9 fold) and HIV-1 (2.7 fold) on the surface of the composite. The inclusion of Ag-ion releasing zeolites into 3D-printable resin can result in stable colloids that generate composites with improved mechanical properties and antiviral properties.

Nanofiber-in-microfiber carbon/silicon composite anode with high silicon content for lithium-ion batteries

Silicon-rich anodes are desired to leverage the energy capacity of lithium-ion batteries (LIBs) towards critical markets. We prepared new silicon-rich composite anodes with a nanofiber-in-microfiber architecture using a co-axial electrospinning setup. A polyvinyl alcohol (PVA) solution that allows high silicon content serves as the central stream, which holds silicon nanoparticles into short, branched composite nanofibers. These nanofibers were wrapped by long, ductile microfibers made of polyacrylonitrile (PAN) that is supplied in the sheath fluid. After carbonization, the received carbon/silicon composites were tested as the anode of LIBs, in which the silicon-rich nanofibers host the majority of lithium ions while their thin carbon skin originated from PVA promotes the conductivity and charge transfer. The outside PAN-derived microfibers provide needed structural support for those encapsulated silicon-rich nanofibers, making the final composites also an integrated, three-dimensional current collector. The nanofibrous morphology and the void space in between help accommodate the notorious volume expansion issues during lithiation/delithiation. The new composites were confirmed on their nanofiber-in-microfiber configuration. With a Si content of 40%, this unique fibrous anode material achieves ∼900 mAh g−1 specific capacity and ∼90% capacity retention from cycle 50 to cycle 250 by effectively balancing some major challenges associated with silicon-rich anodes.

Broadband electromagnetic wave absorption of Fe@polyaniline-derived carbon composites with nitrogen-doping

An in-situ carbonization process was used to prepare nitrogen-doped [email protected] composites, from the complex matrix of polyaniline and iron, for electromagnetic wave (EMW) absorption. The basic idea is to introduce a variety of EMW absorption mechanisms, including dipole polarization due to the nitrogen doping and multiple interface reflection owing to the structural collapse. By adjusting the ratio of the components in the complex, EMW absorption performance of the final composites could be readily optimized while the mass ratio of Fe2O3/polyaniline was 0.6. Specifically, a reflection loss of −66.92 dB at 2.46 mm can be achieved, while an effective absorption bandwidth of 6.40 GHz (11.60 GHz–18.00 GHz) at 2.36 mm.

Strengthening and Toughening CNTs/Mg Composites by OpTimizing the Grinding Time of Magnesium Powder.

In this paper, CNT/Mg composites with high compressive properties were prepared by using Ni-plated CNT and pure magnesium powder as raw materials through the grinding of magnesium powder, ball-milling mixing and hot-pressing sintering. The effect of grinding time for finer magnesium powder on the microstructure and properties of the final composites was studied mainly by SEM, XRD, HRTEM and compression tests. The results show that with the prolongation of milling time, the magnesium particle size decreases gradually and the CNT dispersion becomes more uniform. Moreover, the nickel layer on the surface of CNT reacts with highly active broken magnesium powder in the sintering process to generate MgNi2 intermediate alloy, which significantly improves interface bonding. The strength and fracture strain of composites are significantly increased by the combined action of the uniform distribution of CNTs and strong interface bonding from the MgNi2 phase. The compressive strength, yield strength and fracture strain of the composites, prepared with a 60 h grinding of magnesium powder, reached 268%, 272% and 279% of those in composites without the grinding of magnesium powder.

Electrochemical performance of rGO/AFCNT composite and fabrication of supercapacitor electrode

An aqueous electrolyte-based supercapacitor electrode of graphene and amine-functionalized multiwall carbon nanotubes (AFCNT) is reported. Amine groups were covalently introduced on the surface of Carbon nanotubes (CNT) by diazonium reaction. In-situ reduction of graphene oxide over amine functionalized carbon nanotube template resulted the final composite. At current density of 1 A/g the electrode showed 384 F/g specific capacitance. The electrode had an energy density of 53.33 Wh/kg and power density of 499.13 W/kg. The electrode evinced almost 90% of capacitance retention even at elevated current density of 5 A/g. • Composite of Graphene/- NH 2 functioned MWCNT developed for supercapacitor electrode. • Composite shows specific capacitance of 384 F/g at a current density of 1 A/g. • Introduction of hydrophilic amine group prevents the restacking of graphene layers effectively. • The electrode shows retention of 90% capacitance at current density as high as 5 A/g.