Graphene Nanoplatelets Content Research Articles

Role of graphene concentration on electrochemical and tribological properties of graphene-poly(methyl methacrylate) composite coatings.

This study aims to investigate the influence of graphene nanoplatelet (GNP) concentration on the electrochemical and tribological properties of GNP-poly(methyl methacrylate) (PMMA) composite coatings. GNP-PMMA coatings were prepared with varying GNP concentrations (0.5, 1.0, 3.0, and 5.0wt %) using the drop-casting method onto AA6061 aluminum alloy substrates. Results showed that the addition of 1.0wt % GNP increased the tensile strength of PMMA but further increase reduced the tensile strength and fracture strain of the composites. Permeability studies indicated that 1.0GNP-PMMA had the lowest water vapour transition rate. All GNP-PMMA coatings showed a higher coating resistance and impedance modulus at the lowest frequency compared to neat PMMA with 1.0GNP-PMMA having the highest |Z|0.01 Hz value in comparison to the composites with higher GNP concentrations. According to Raman mapping, an increase in the concentration of GNP in the composite resulted in the agglomeration of graphene, which caused the debonding of the graphene-PMMA interfaces and also resulted in a higher number of shear fronts and other defects on the fracture surface that reduced barrier properties of graphene. The specific wear rate of 1.0GNP-PMMA was lower than that of neat PMMA, indicating improved wear resistance. The coefficient of friction was lowest for 5.0GNP-PMMA, although this was due to a higher amount of material being transferred to the counterface. Accordingly, optimizing the GNP concentration enables the development of high-performance PMMA coatings with enhanced strength, improved barrier properties, and reduced wear rates, making them well-suited for applications such as corrosion protection and tribological coatings.

Graphene-Based Strain Sensing of Cementitious Composites with Natural and Recycled Sands.

Structural health monitoring is crucial for ensuring the safety and reliability of civil infrastructures. Traditional monitoring methods involve installing sensors across large regions, which can be costly and ineffective due to the sensors damage and poor compliance with structural members. This study involves systematically varying the graphene nanoplatelets (GNPs) concentration and analyzing the strength performance and piezoresistive behavior of the resulting composites. Two different composites having natural and recycled sands with varying percentages of GNPs as 2%, 4%, 6%, and 8% were prepared. Dispersion of GNPs was performed in superplasticizer and then ultrasonication was employed by using an ultrasonicator. The four-probe method was utilized to establish the piezoresistive behavior. The results revealed that the compressive strength of mortar cubes with natural sand was increased up to a GNP content of 6%, beyond which it started to decline. In contrast, specimens with recycled sand showed a continuous decrease in the compressive strength. Furthermore, the electrical resistance stability was observed at 4% for both natural and recycled sands specimens, exhibiting linearity between the frictional change in the resistivity and compressive strain values. It can be concluded from this study that the use of self-sensing sustainable cementitious composites could pave their way in civil infrastructures.

Ultrasensitive flexible strain sensors based on graphene nanoplatelets doped poly(ethylene glycol) diglycidyl ether: Mask breathing monitoring for the Internet of Things

Ultrasensitive and stretchable strain sensors based on graphene nanoplatelet (GNP) doped poly(ethylene glycol) diglycidyl ether (PEGDGE) for human motion monitoring purposes with remote tracking by using Internet of Things (IoT) technologies are synthesized. The quasi–static and cycling responses under both tensile and compression conditions of nanocomposites are studied in detail. On one hand, quasi-static analysis shows very high values of the gauge factor, reaching values around 50–100 at low strain levels (1–2%) and 1000–2500 at high strain levels (10%) in tensile mode, with increasing sensitivity with decreasing GNP content. In addition, electromechanical response under 500 tensile and compression load cycles up to 1%, 2.5%, and 5% strain levels proves their high stability and as a result, their high sensitivity to detect a low degree of strain levels. Three general proofs–of–concept demonstrate that these sensors can detect several types of deformations such as pressure, bending, and twisting. Finally, human breathing is monitored with the sensor attached to a conventional mask. Different breath rhythms combining the calm and excited states of a person walking are remotely sent and monitored on the internet by using different IoT platforms.

MECHANICAL BEHAVIOR OF HIGH-DENSITY POLYETHYLENE REINFORCED WITH GRAPHENE NANOPLATELETS AND JUTE FABRIC

Owing to sustainable characteristics, natural lignocellulosic fibers (FNLs) and graphene nanoplatelets (GNP)-reinforced composites are currently seeing applications in a wide range of industrial fields. Thus, in the present work, the mechanical, and flexural properties of high-density polyethylene (HDPE) reinforced with 0, 0.10, 0.25, and 0.50 wt.% of GNP combined with 50 vol.% of Juta fabric were investigated. In particular, the Juta/HDPE/0.25%GNP composite outperformed the strength of those described in the literature, even some with higher GNP. Enhancements of 38% were observed for the composite’s flexural modulus as compared to the GNP-free Juta/HDPE composite. Regarding the tensile properties, the ductility of the Juta/HDPE/0.25%GNP was increased by 112% when compared to the Juta/HDPE. Moreover, the toughness of the Juta/HDPE/0.25%GNP was 161% superior to the Juta/HDPE composite. SEM analysis of the fracture surfaces showed that, as GNP concentration rises, the fracture mechanisms change from shear band to a complex mixture of fibrillation, tearing, and crazing. Consequently, the results reveal the novel Juta/HDPE/0.25%GNP nanocomposite as a promising material for engineering applications.

Thermally conductive and anti-corrosive epoxy composite coatings by synchronously incorporating boron nitride/graphene fillers and polyvinyl pyrrolidone

With the development of modern science and technology, the coatings with the single function of anti-corrosion have failed to cover the special requirements in various practical applications. Particularly, the good heat dissipation effect of anti-corrosive coatings is highly demanded in some devices like electrical machinery, heat exchanger and printed circuit board. Here, a facile, eco-friendly, low-cost method is developed to fabricate thermally conductive and anti-corrosive composite coatings by mixing fillers (including boron nitride (BN) and graphene nanoplatelet (GNP)), polyvinyl pyrrolidone (PVP) and waterborne epoxy resin (WER). The hybridization of BN and GNP is used to provide more barriers to delay the penetration of corrosive medium and construct a denser heat conduction network in the composite coatings. PVP is selected as the compatibilizer to further improve the anti-corrosion and thermal conductivity of composite coatings. The effects of filler types and contents on the anti-corrosive and thermally conductive properties are researched. At the loading of 30 wt% BN and 0.5 wt% GNP, the BN@GNP/PVP/WER coating reaches the optimizing anti-corrosive ability, where the |Z| value holds around 6.5 × 109 Ω cm2 after soaking in the corrosive medium for 7 days, and the Icorr and Ecorr values are 1.9 × 10−9 A/cm2 and -0.62742 V, respectively. Meanwhile, this coating displays great heat conduction with the thermal conductivity of 0.87 W/mK at about 30 wt% filler loading. Moreover, the electrical properties and hydrophilicity of coatings at different filler formulations are studied. It is worth noting that the higher electrical conductivity of the coatings at higher GNP content may accelerate the corrosion rate. This study provides a simple route for the design and manufacture of highly anti-corrosive and heat-conducting composite coatings, which exhibits great potential application in next-generation electronic packaging and devices.

High pyroelectric performances of graphene nanoplatelet reinforced polyvinylidene fluoride composite film

AbstractAs a semi‐crystalline polymer with pyroelectric properties, polyvinylidene fluoride (PVDF) has demonstrated great potential in developing smart and multifunctional materials. However, the low level of β phase in pure PVDF restricts its pyroelectric performance and applications. Selecting graphene nanoplatelets (GNP) as the reinforcing filler, this current work pioneeringly investigates the pyroelectric performances of GNP/PVDF composite films subjected to different scenarios. It is found that the addition of GNP can significantly enhance the formation of the β phase in PVDF and the pyroelectric performances of the composite. When the GNP content is 10 wt%, the pyroelectric coefficient of the GNP/PVDF composite film reaches up to 260 μC/m2K, which is about 10 times that of pure PVDF. Parametric study demonstrates that decreasing the thickness of the composite film and increasing the temperature are beneficial to improve the pyroelectric performances. Moreover, the addition of GNPs cannot only enhance the pyroelectric performance, but also improves the thermal stability of the composite film. The work is envisaged to provide guidelines for the design and manufacturing PVDF‐based sensors with improved sensitivity.

Multi-objective optimization for maximum fundamental frequency and minimum cost of hybrid graphene/fibre-reinforced nanocomposite laminates

The present article proposes a multi-objective optimization study aiming at the optimal cost-effective design of nano-reinforced laminates. To maximize the fundamental frequency and minimize the cost, a hybrid laminate is studied, introducing both conventional fibres and graphene nanoplatelets reinforcement. A multi-objective genetic algorithm optimization is adopted to provide the optimal natural frequency and cost for the laminate. Optimization is implemented using the Non-dominated Sorting Genetic Algorithm II (NSGA-II), which converges to near-optimal solutions for all scenarios tested. The vibration problem is solved using the finite element method and the first-order shear deformation theory. Effective material properties are derived using micromechanical equations. Different optimization problems are solved using one to four types of design variables, including graphene and fibre distribution along the thickness, layer thickness, and fibre angles. Results indicate that increasing the graphene nanoplatelets content and keeping the minimum fibre content leads to cost-effective design. A drastic increase in the fundamental frequency and decrease in the cost is obtained for the hybrid graphene/fibre-reinforced laminate compared to conventional fibre-reinforced composites.

Effect of graphene nanoplatelets on mode I fracture Toughness of epoxy adhesives under water aging conditions

ABSTRACT In this work, graphene nanoplatelets (GNP) are used to reinforce epoxy adhesives, and the effects of GNP on mode I fracture toughness of adhesive under water aging condition are studied through double cantilever beam (DCB) test. Although the GNP reinforced adhesives deliver slightly higher GIC than neat epoxy before water aging, they exhibit an exceptional 21.93% higher GIC after immersing in water for 56 d, at a GNP content of 0.25 w.t.%. According to the experimental results, the effectively dispersed GNP could significantly alleviate the degradation rate in mode I fracture toughness due to the water aging. For example, compared to the non-aging condition, the mode I fracture toughness of neat epoxy decreases by 29.19% after 56 d of water aging. In a stark contrast, the degradation rate for 0.25 w.t.% GNP reinforced adhesive is only 15.76%. In addition, it is observed that GNP greatly improves the fracture surface roughness of DCB samples, which suggests that the incorporation of GNP is able to delay the negative effect of water aging on mode I fracture toughness of adhesive by lowering the diffusion of water into the adhesive, while increasing torturous of the crack propagation path.

Microwave heating of graphene nanoplatelet polymer composites: Experimental and finite element study

AbstractCompared with contemporary electrofusion techniques that use embedded wires for Joule heating, microwave heating may facilitate the joining of thermoplastic polymer components, promising shortened fusion periods, superior heating uniformity, and reduced energy consumption. This study investigates the fabrication of multifunctional polylactide acid (PLA) composites with strong microwave absorption using graphene nanoplatelets (GNP). GNP/PLA nanocomposites were fabricated using a two‐step scalable manufacturing method, that is, solution blending and hot compression molding. The GNP content of the composites ranged from 0% to 8% by weight. The samples were characterized for dielectric permittivity, heat capacity, and electrical and thermal conductivity. Thermal imaging was used to investigate the efficacy of microwave heating in GNP/PLA nanocomposites as a function of microwave power and filler weight fractions. The microwave heating process in GNP composites was studied using multi‐physics finite element software. The experimental results were compared to numerical model predictions for maximum temperature and microwave energy absorbed. The produced nanocomposites were discovered to have strong microwave absorption characteristics and hence rapid heating, making this type of composite a prospective choice for gasket materials that facilitate fusion bonding for thermoplastic‐based components via localized heating.

Upcycled graphene integrated fiber-based photothermal hybrid nanocomposites for solar-driven interfacial water evaporation

Solar-driven interfacial evaporation is an efficient and viable solution for providing freshwater, especially in remote areas that utilize sunlight for water purification and desalination systems. This study proposes a practical preparation method for a photothermal nanocomposite, compromising Polyacrylonitrile (PAN) nanofibrous membrane, crosslinked PVA, and upcycled Graphene Nanoplatelets (GNP). The synergistic effect between the PAN nanofibers and PVA/GNP nanocomposite and the contributing factors to the overall performance is examined. It was found that the initial thickness of the PAN nanofibrous layer has an inverse effect on the evaporation rate. The obtained results indicated that while the GNP content enhances the photothermal activity, it deteriorates the water absorbency of the nanocomposite; thus, an optimized concentration should be obtained. By investigating different parameters for the evaporator, we obtained an evaporation rate of 1.40 kg/m2h under 1 sun of illumination.

Investigating the Effects of Graphene Nanoplatelets and Al4C3 on the Tribological Performance of Aluminum-Based Nanocomposites

The study investigates the effects of graphene nanoplatelets (GNPs) on the tribological properties of aluminum-based nanocomposites, both annealed after extrusion and non-annealed. It also examines the role of nanosized Al4C3 (aluminum carbide), which forms in the annealed Al/GNPs nanocomposite, on the tribological performance of the nanocomposites. The nanocomposites were fabricated using the powder metallurgy method. The microstructure of the composite materials was characterized using SEM, EDS, XRD and TEM techniques. The coefficient of friction (CF) and mass wear of the composites were measured using a pin-on-disk test under dry sliding friction conditions. The results showed that adding GNPs increased the coefficient of friction (CF) of the nanocomposites by up to 44% at 0.1 wt.% GNP, but the CF decreased by 15% at 1.1 wt.% GNP. The optimal concentration of GNPs for minimizing the CF and mass wear of Al-based nanocomposites was 0.1 wt.%. Additionally, the presence of Al4C3 in the annealed Al/GNP nanocomposite had a positive effect on the CF at low GNP concentrations, with a 38% increases at 0.1 wt.% GNP, but this effect diminished as the GNP concentration increased. The study also found that the mass wear of the nanocomposites increased with the GNP concentration, with a 46% increase in the mass wear from 0.1 wt.% GNP to 0.5 wt.% GNP and a 202% increase from 0.1 wt.% GNP to 1.1 wt.% GNP. The presence of Al4C3 also affected the mass wear, with the effect diminishing as the GNP concentration increased. The study observed an increase in the mass wear with the increase in the GNP concentrations, but the mass wear of the annealed Al/GNPs with 1.1 wt.% GNP and Al4C3 was 52% lower than the Al composite with 1.1 wt.%. Overall, this study provides insights into the role of GNPs and Al4C3 on the tribological performance of aluminum-based nanocomposites.

Electrical Transport Mechanisms in Graphene Nanoplatelet Doped Polydimethylsiloxane and Application to Ultrasensitive Temperature Sensors.

The temperature effect on electronic transport mechanisms in graphene nanoplatelet (GNP) doped polydimethylsiloxane (PDMS) for temperature sensing applications has been investigated under electrical impedance spectroscopy (EIS) analysis. AC measurements showed a very prevalent frequency-dependent behavior in low filled nanocomposites due to the lower charge density. In fact, 4 wt % GNP samples showed a nonideal capacitive behavior due to scattering effects. Therefore, the standard RC-LRC circuit varies with the substitution of capacitive elements by CPEs, where a CPE is a constant phase element which denotes energy dissipation. In this regard, the temperature promotes a prevalence of scattering effects, with an increase of resistance and inductance and a decrease of capacitance values in both RC (intrinsic and contact mechanisms) and LRC (tunneling mechanisms) elements and, even, a change from ideal to nonideal capacitive behavior as in the case of 6 wt % GNP samples. In this way, a deeper understanding of electronic mechanisms depending on GNP content and temperature is achieved in a very intuitive way. Finally, a proof-of-concept carried out as temperature sensors showed a huge sensitivity (from 0.05 to 11.7 °C-1) in comparison to most of the consulted studies (below 0.01 °C-1), proving, thus, excellent capabilities never seen before for this type of application.

Mechanical properties of binderless tungsten carbide enhanced via the addition of ZrO2-20 wt% Al2O3 composite powder and graphene nanosheets

As an alternative to conventional tungsten carbide materials, binerless tungsten carbide (BTC) can be used in a variety of applications, such as high-speed cutting tools, rock drilling and extraction, and wear-resistant components. The absence of the metallic bonding phases solves the problems of oxidative corrosion and softening of the material during high-speed cutting process. However, the fabrication of high strength and toughness BTC ceramics remains a huge challenge. In this paper, ZrO2-20 wt% Al2O3 composite powder and graphene nanoplatelets (GNPs) were used as the reinforced phases to fabricate high performance BTC ceramics. The influence of GNPs contents on the densification, microstructure and mechanical properties of oscillatory pressure sintered BTC ceramics with 8 wt% composite powder was evaluated. The synergistic effect of ZrO2-20 wt% Al2O3 composite powder and GNPs exerted a critical role on the densification process and microstructural evolution. The produced BTC ceramics had the densest microstructure and optimal mechanical characteristics when the GNPs content reached up to 0.2 wt%; the flexural strength, Vickers hardness, fracture toughness and relative density were up to 1480 MPa, 23.72 GPa, 8.68 MPa·m1/2 and 99.8%, respectively.

The Effect of Graphene Nanoplatelets Content on the Hardness of Mg6%Zn0.2%Mn Composites

The effect of graphene nanoplatelets (GNPs) content on the hardness of magnesium-based composites was studied. A magnesium-based composite, Mg6%Zn0.2%Mn with graphene nanoplatelets (GNPs), was fabricated via powder metallurgy process at room temperature and compressive pressures of 50kN for 20 minutes, which was then sintered at 500°C for 2 hours. It produced significant grain refinement microstructure. The change in microstructure was examined by 3D microscope analysis, and the hardness value was evaluated using the Vickers microhardness apparatus. This study demonstrated the importance of GNPs reinforcement with zinc and manganese for microhardness analysis in the sintered Mg-based GNPs composites. It also portrayed their influence on grain refinement of the microstructure. The hardness results agreed with the microstructure results, proving that the presence of GNPs increases the hardness of the Mg-based composites.

Synthesis, stability, and heat transfer behavior of water and graphene nanoplatelet-based nanofluid for cool thermal storage applications

This study aims to synthesize stable nano-enhanced phase change materials (NEPCM) using deionized (DI) water and graphene nanoplatelets (GNPs) with the aid of three different surfactants (CTAB, SDBS, and GA). The study also investigates the dynamic behavior of the NEPCM during solidification and melting in a spherical encapsulation. GA-GNP dispersion showed prolonged stability based on zeta potential distribution (ZP) and UV–vis absorbance after 60 days of preparation. The effect of GNP concentration (0.25, 0.50, 0.75, and 1.00 wt%) on the heat transfer properties of the NEPCM was investigated using differential scanning calorimetry (DSC), temperature-time (T-t) profiles, and TC measurements. The maximum energy storage density decreased by 8.56 % and 15.3 % for 1.00 wt% GNPs added to DI-water during melting and crystallization, respectively, at a heating rate of 5 K/min. The thermal conductivity (TC) increased by 59.1 % and 10.8 % in the solid and fluid circumstances, correspondingly. Transient temperature results showed that GA significantly reduced super cooling (SC) by 47.6 % and eliminated it completely at a concentration of 1.00 wt% GNP-NEPCM. The maximum reduction in solidification rate was 26.4 % with 1.00 wt% GNP-NEPCM at a −7 °C constant heat transfer fluid (HTF) temperature. The melting duration was reduced by 33 % by adding 0.50 wt% GNPs, while the melting duration was prolonged at a concentration of 1.00 wt% due to the viscosity augmentation of molten layers. In conclusion, the proposed stable NEPCM formulation has great potential for use as an energy-efficient storage medium in the CTES system.

Microstructures and mechanical properties of Al nanocomposites hybrid-reinforced with B4C, carbon nanotubes and graphene nanoplatelets

To improve the mechanical properties of Al-30%B4C composites, modified carbon nanotubes (CNTs) and graphene nanoplatelets (GNPs) were added. The Al/B4C composites with different content of CNTs and GNPs were fabricated via ball milling and hot press. The B4C particles were homogeneously distributed, and the B4C/Al interface was tightly bonded due to AlB2 and Al3BC. With increase of CNTs content, the composites strength increased. The compressive strength of the Al-30%B4C-0.75%CNT-0.25%GNP composite was enhanced by 46% compared with that of the Al-30%B4C composite. The interface bonding and strengthening mechanisms of CNT-GNP hybrid were studied in detail. The reinforcements mainly reinforced the nanocomposites by Orowan, dislocation, grain refinement strengthening and load transfer. After calculation, CNT-GNP hybrid has lower contribution in thermal mismatch and Orowan strengthening due to the larger size. The load transfer efficiency of the CNT-GNP hybrid was significantly higher than that of the CNTs and GNPs, as the optimised interface structure and interconnected structure of the hybrids contributed to its high strength.

Sustainable Microfabrication Enhancement of Graphene Nanoplatelet-Reinforced Biomedical Alumina Ceramic Matrix Nanocomposites

Studies about adding graphene reinforcement to improve the microfabrication performance of alumina (Al2O3) ceramic materials are still too rare and incomplete to satisfy sustainable manufacturing requirements. Therefore, this study aims to develop a detailed understanding of the effect of graphene reinforcement to enhance the laser micromachining performance of Al2O3-based nanocomposites. To achieve this, high-density Al2O3 nanocomposite specimens were fabricated with 0 wt.%, 0.5 wt.%, 1 wt.%, 1.5 wt.%, and 2.5 wt.% graphene nanoplatelets (GNPs) using a high-frequency induction heating process. The specimens were subjected to laser micromachining. Afterward, the effects of the GNP contents on the ablation depth/width, surface morphology, surface roughness, and material removal rate were studied. The results indicate that the micro-fabrication performance of the nanocomposites was significantly affected by the GNP content. All nanocomposites exhibited improvement in the ablation depth and material removal rate compared to the base Al2O3 (0 wt.% GNP). For instance, at a higher scanning speed, the ablation depth was increased by a factor of 10 times for the GNP-reinforced specimens compared to the base Al2O3 nanocomposites. In addition, the MRRs were increased by 2134%, 2391%, 2915%, and 2427% for the 0.5 wt.%, 1 wt.%, 1.5 wt.%, and 2.5 wt.% GNP/Al2O3 nanocomposites, respectively, compared to the base Al2O3 specimens. Likewise, the surface roughness and surface morphology were considerably improved for all GNP/Al2O3 nanocomposite specimens compared to the base Al2O3. This is because the GNP reinforcement reduced the ablation threshold and increased the material removal efficiency by increasing the optical absorbance and thermal conductivity and reducing the grain size of the Al2O3 nanocomposites. Among the GNP/Al2O3 nanocomposites, the 0.5 wt.% and 1 wt.% GNP specimens showed superior performance with minimum defects in most laser micromachining conditions. Overall, the results show that the GNP-reinforced Al2O3 nanocomposites can be machined with high quality and a high production rate using a basic fiber laser system (20 Watts) with very low power consumption. This study shows huge potential for adding graphene to alumina ceramic-based materials to improve their machinability.

Modelling the anisotropic thermal conductivity of 3D logpile structures

Assessing and predicting the thermal conductivity (κ) of macroporous materials is particularly important for additive manufactured 3D structures, as they offer considerable potential for tuning architectures and properties. In this work, finite element methods (FEM) are used to simulate the transient plane source test in 3D logpile lattices, approaching the effect of interfacial thermal contact resistances on κ measurement. Besides, the influence of different geometrical parameters (rod diameter, macropore size and overlapping between rods in consecutive layers) and the κ of the strut material on the anisotropic thermal conductivity of 3D lattices are investigated. The models are validated using experimental data for 3D composite structures of γ-Al2O3 with graphene nanoplatelet contents up to 18 vol%, as well as with reported data for alike scaffolds, all printed by robocasting. Results have strong impact for the application of novel 3D structures in energy production and storage, catalysis and heat transfer-related fields.

Vibration damping properties of graphene nanoplatelets filled glass/carbon fiber hybrid composites

Abstract The present study investigates the effect of carbon fiber hybridization and graphene nanoplatelets inclusion on the vibration damping properties of glass fiber reinforced polymer composites. The hand layup method was utilized with hot press molding in hybrid/non-hybrid composite plate production. A total of sixteen laminates, eight containing pure glass/epoxy and pure carbon/epoxy, and the remainder containing glass/carbon, were stacked in four different arrays and impregnated with an epoxy matrix to provide a hybrid/non-hybrid configuration. In the first hybrid configuration, the glass fiber fabric is on the outer surface and the carbon fiber fabric is on the inside of the composite plate; in the second configuration, the opposite of this sequence was used. Graphene Nanoplatelets (GNPs) were added into the epoxy resin in different weight fractions (0, 0.1, 0.25, and 0.5 wt%). Experimental modal analysis was performed to evaluate the natural frequency and damping ratios of the GNPs modified/unmodified test samples. According to the results obtained, carbon fiber hybridization not only increased the natural frequency but also caused a decrease in the damping ratio of the glass fiber reinforced composite material. On the other hand, incorporating 0.5% by weight of GNPs into the epoxy matrix improved damping ratios by approximately 42.1, 51.6, 16.7 and 17.2% for the G05, GC05, CG05 and C05 samples, respectively, compared to the pure samples. Also, a decrease in natural frequency and loss storage values were observed at high GNPs content.

Graphene nanoplatelets composite resin curing and thermal diffusivity determination by photothermal techniques

In this work, the thermal diffusivity for graphene nanoplatelets (GNPs) incorporated into an acrylic resin with concentrations between 0.02 and 0.12 wt% were measured using the thermal wave resonant cavity (TWRC). An increased in this thermal parameter with increasing the concentration of the GNPs was observed. Moreover, the effect of the GNPs concentration on the curing time of resin nanocomposites was measured using the photoacoustic (PA) technique. The results showed that for higher GNPs concentrations, the curing time was higher for a fixed laser power. Samples were characterized by UV–Vis, TEM and FTIR techniques. On the other hand, the Shore hardness was measured for the cured resins, observing a hardness increase with GNPs concentration. The development of synthesis of new nanocomposites for curing (as 3D printing resins) will provide a better understanding of the physicochemical, thermal and mechanical properties of large-scale composite structures for applications in areas of medicine for implants and scaffolds.