Nanoscale Reinforcement Research Articles

Radially Grown Graphene Nanoflakes on Carbon Fibers as Reinforcing Interface for Polymer Composites

The development of nanoscale reinforcements, which can tailor the interfacial strength and impart multiple functionalities on carbon fiber reinforced polymer (CFRP) composites, remains a challenge ...

Vibration analysis of fluid-conveying multi-scale hybrid nanocomposite shells with respect to agglomeration of nanofillers

The vibration problem of a fluid conveying cylindrical shell consisted of newly developed multi-scale hybrid nanocomposites is solved in the present manuscript within the framework of an analytical solution. The consistent material is considered to be made from an initial matrix strengthened via both macro- and nano-scale reinforcements. The influence of nanofillers’ agglomeration, generated due to the high surface to volume ratio in nanostructures, is included by implementing Eshelby-Mori-Tanaka homogenization scheme. Afterwards, the equivalent material properties of the carbon nanotube reinforced (CNTR) nanocomposite are coupled with those of CFs within the framework of a modified rule of mixture. On the other hand, the influences of viscous flow are covered by extending the Navier-Stokes equation for cylinders. A cylindrical coordinate system is chosen and mixed with the infinitesimal strains of first-order shear deformation theory of shells to obtain the motion equations on the basis of the dynamic form of principle of virtual work. Next, the achieved governing equations will be solved by Galerkin’s method to reach the natural frequency of the structure for both simply supported and clamped boundary conditions. Presenting a set of illustrations, effects of each parameter on the dimensionless frequency of nanocomposite shells will be shown graphically.

Interfacial reinforcement of hybrid composite by electrophoretic deposition for vertically aligned carbon nanotubes on carbon fiber

In this paper, vertically aligned carbon nanotube/carbon fiber (VACNT/CF) hybrids was prepared by electrophoretic deposition (EPD) under mild conditions. The coaxial cylindrical electrode with CF filament as the cathode was employed to ensure dense VACNT arrays deposited on CF surface at low deposition voltage. The effect factors on the carbon nanoparticles alignment were investigated by the micro-morphology observations of hybrid fibers, including the diameter of carbon nanoparticles, types of solvent, deposition voltages, deposition time and the concentrations of carbon nanoparticles in dispersion. The results indicate that the optimum electrophoretic deposition conditions for vertically aligned hybrid fibers is the diameter of carbon nanoscale reinforcements of 110–170 mm, acetonitrile (ACN) as the dispersion medium, deposition voltage of 30 V, deposition time of 20 s and dispersion concentration of the carbon nanoparticles of 0.01 mg/mL. Single fiber tensile testing was performed and manifested that EPD in a coaxially cylindrical electric field was not destructive and could preserve the mechanical properties of CF filaments. Results of interphase properties tests demonstrated that the contact angle and the interfacial shear strength (IFSS) were significantly improved by 48.3% and 58.1% compared to that of as-recieved CF, respectively. The interfacial enhancement mechanism was also explored in details.

Fe3O4 Nanoparticle-Reinforced Magnesium Nanocomposites Processed via Disintegrated Melt Deposition and Turning-Induced Deformation Techniques

Magnesium nanocomposites, with nano-scale ceramic reinforcements, have attracted a great deal of attention for several engineering and biomedical applications in the recent past. In this work, superparamagnetic iron oxide nanoparticles, Fe3O4, with their unique magnetic properties and the ability of being bio-compatible and non-toxic, are reinforced to magnesium to form Mg/(1, 2, and 3 wt %) Fe3O4 nanocomposites. These nanocomposites were fabricated using the conventional disintegrated melt deposition (DMD) technique followed by extrusion. Further, the materials were also processed using the novel turning-induced-deformation technique where the chips from turning process are collected, cold compacted, and hot extruded. The materials processed via the two techniques were compared in terms of microstructure and properties. Overall, the Mg/Fe3O4 nanocomposites, processed via both routes, exhibited a superior property profile. Further, the turning-induced deformation method showed promising results in terms of improved properties of the nanocomposites and serves as a great route for the recycling of metallic materials.

Colloidal Gelation in Liquid Metals Enables Functional Nanocomposites of 2D Metal Carbides (MXenes) and Lightweight Metals.

Nanomaterials dispersed in different media, such as liquids or polymers, generate a variety of functional composites with synergistic properties. In this work, we discuss liquid metals as the nanomaterials' dispersion media. For example, 2D transition-metal carbides and nitrides (MXenes) can be efficiently dispersed in liquid Ga and lightweight alloys of Al, Mg, and Li. We show that the Lifshitz theory predicts strong van der Waals attraction between nanoscale objects interacting through liquid metals. However, a uniform distribution of MXenes in liquid metals can be achieved through colloidal gelation, where particles form self-supporting networks stable against macroscopic phase segregation. This network acts as a reinforcement boosting mechanical properties of the resulting metal-matrix composite. By choosing Mg-Li alloy as an example of ultralightweight metal matrix and Ti3C2Tx MXene as a nanoscale reinforcement, we apply a liquid metal gelation technique to fabricate functional nanocomposites with an up to 57% increase in the specific yield strength without compromising the matrix alloy's plasticity. MXenes largely retain their phase and 2D morphology after processing in liquid Mg-Li alloy at 700 °C. The 2D morphology enables formation of a strong semicoherent interface between MXene and metal matrix, manifested by biaxial strain of the MXene lattice inside the metal matrix. This work expands applications for MXenes and shows the potential for developing MXene-reinforced metal matrix composites for structural alloys and other emerging applications with metal-MXene interfaces, such as batteries and supercapacitors.

Vat Photopolymerization 3D Printing of Nanocomposites: A Literature Review

Abstract Nanocomposites have been widely used to improve material properties. Nanoscale reinforcement materials in vat photopolymerization resins improve the hardness, tensile strength, impact strength, elongation, and electrical conductivity of the printed products. This paper presents a literature review on the effects of reinforcement materials on nanocomposite properties. Additionally, preprocessing techniques, printing processes, and postprocessing techniques of nanocomposites are discussed. The nanocomposite properties are summarized based on their applications in the mechanical, electrical and magnetic, and biomedical industries. Future research directions are proposed to improve the material properties of printed nanocomposites.

Spatial distribution of nanodiamond and its effect on mechanical behaviour of epoxy based composite using 2D modulus mapping

The present study has taken an initiative to understand the distribution of nanophase reinforcement in polymer matrix and their behaviour during loading, using 2D modulus mapping. The composite system, being studied here, is a nanodiamond reinforced epoxy resin matrix. Modulus Mapping gives an idea of distribution of nanodiamond in matrix, in terms of spatial distribution of micron level higher modulus regions in epoxy matrix. The modulus mapping studies, carried out on composites with and without application of uniaxial tensile stresses, reveals the active role being played by nanodiamond in modulating the mechanical behaviour of the epoxy matrix and the evolution of distribution of the former with application of stress. Hardness and elastic modulus of epoxy is improved by ∼470% and ∼94% with 1 wt% nanodiamond. The stiffening effect of nanodiamond dispersed in epoxy matrix, evaluated through experiment is also in concurrence with results simulated using finite element method (FEM) of the representative volume element (RVE). Tensile strength and fracture toughness also showed an improvement of ∼56% and ∼85%, respectively, with 0.3 wt% ND. Interestingly, % strain (at break) also increased by ∼66%. TEM showed good dispersion and strong interaction of NDs with epoxy matrix. SEM analysis validates crack pinning and crack deflection as dominant toughening mechanism, while, efficient load sharing between ND and epoxy is found as main strengthening mechanism. As a whole, this study develops 2D modulus mapping technique as a generalized tool for evaluating the quality of dispersion of the nanoscale reinforcement phases and their role in mechanical behaviour of the macro-scale composite structures.

Vibration analysis of graphene oxide powder-/carbon fiber-reinforced multi-scale porous nanocomposite beams: A finite-element study

Application of the Rayleigh-Ritz method for the vibration problem of a porous multi-scale hybrid nanocomposite graphene oxide powder (GOP)/carbon fiber (CF)-reinforced beam is shown here for the first time on the basis of a new refined higher-order shear deformation beam theory. The structure consists of an initial matrix which is strengthened via both macro- and nano-scale reinforcements. Herein, GOPs and CFs are selected to be dispersed inside the resin. Moreover, the influences of porosity are included, too. The governing equations of the problem are achieved in the framework of a new refined higher-order beam model. Afterward, the Rayleigh-Ritz well-known finite-element method (FEM) is implemented to solve the problem for various boundary conditions (BCs). The validity of the presented formulation is checked by comparing the results of the employed FEM with those achieved from the Navier solution. it is shown that hybrid nanocomposites are able to support higher natural frequencies in comparison with either conventional fiber-reinforced composites or common two-phase GOP-reinforced nanocomposites.

Enhanced interfacial strength of aramid fiber reinforced composites through adsorbed aramid nanofiber coatings

Aramid fibers are well-known for their excellent tensile properties and low density but are limited in composite applications due to their inert surface which leads to poor interfacial properties. One method that has shown promise in recent years is the application of nanoscale reinforcements to the surface of the fibers to improve mechanical interaction with the matrix. With aramid fibers, it is ideal to perform an interfacial reinforcement utilizing the dense hydrogen bonding which is responsible for the fibers strength. Here, it is demonstrated that recently developed aramid nanofibers (ANFs) can adsorb onto the surface of macroscale aramid fibers to enhance the interfacial properties through mechanical interlocking with the matrix. A simple and rapid dip-coating process is used to deposit the ANFs on the aramid fiber surface. These ANFs bond with the fiber through physisorption and hydrogen bonding, yielding a 70.27% increase in interfacial shear strength and a 25.6% increase in short beam shear strength in composites prepared by dip-coating unidirectional tape into a solution of ANFs. Notably, the interfacial gains are made while fully preserving the strength of the aramid fiber following the treatment, therefore ensuring in-plane properties of the composite are maintained. This work shows that the introduction of an ANF interphase may present a novel and convenient method to improve the interfacial strength of aramid reinforced composites, enabling cost-effective and simplified production of stronger structural materials.

Thermomechanical wrinkling and strength of sandwich panels with nanoscale or microscale randomly reinforced core

Wrinkling represents one of the failure modes in sandwich structures, although in practical designs the loss of strength and global buckling often occur at lower compressive loads. However, the properties of both polymeric matrix in the facings as well as the polymeric core degrade under an elevated temperature. As a consequence, wrinkling that does not present a problem at the room temperature may become a dominant mode of failure at elevated temperatures. In this article, we suggest that a reinforcement of the core material with stiff random nanoscale or microscale reinforcements may alleviate wrinkling. The solution accounts for the thermal loading history and the effect of temperature on the stiffness of the materials of the core and facings. While nano or microscale reinforcements increase the capacity of the structure to resist wrinkling, the strength of the core may be compromised due to the presence of such inclusions in the core material. Accordingly, the residual stresses in the reinforced core are evaluated using a finite-element method and accounting for the effect of temperature on the properties and stresses. It is demonstrated that both wrinkling and the core strength analyses should account for the effect of temperature on the material properties.

Carbon Nano Tube in polymer nanocomposites

Abstract Polymer nanocomposites is novel engineering polymer composites material with nano scale reinforcement. The benefit of nanoscale reinforcement is their high surface-to-volume ratio which is more dominant in properties compared to macro scale reinforcement. Prior studies show that CNT have 1 TPa young’s modulus with some unique electrical and thermomechanical properties. Carbon Nano tube are promising nano fillers due to their unique characteristic in terms of mechanical and functional properties. In this paper, an attempt has been made to identify the research gap in synthesis and properties of Carbon Nano tube along with development of CNT/polymer composites.

A novel and facile fabrication of polyphosphazene nanotube/carbon fiber multi-scale hybrid reinforcement and its enhancing effect on the interfacial properties of epoxy composites

The mechanical properties of carbon fiber (CF) reinforced composites are greatly dependent on the interfacial adhesion between fiber and resin matrix. Introducing nanoscale reinforcements into the interface is an effective approach to improve the interfacial adhesion of CF composites. In this paper, we proposed a facile and effective method for assembling poly(cyclotriphosphazene-co-4,4′-sulfonyldiphonel) nanotube onto CF surface as a novel multi-scale hybrid reinforcement through in situ template polymerization. The effects of surface modification on the surface and interface properties of CF and the resulting composite were investigated. After modification, the interfacial shear strength of fiber reinforced epoxy composites showed an increase of 26.4%. The reinforcing mechanisms were also analyzed, and the improvements on interfacial properties should mainly be attributed to mechanical interlocking effect. In addition, the modification even improved the fiber tensile strength by 6.6–16.3%, rather than deteriorating it.

Layer-by-Layer electrostatic self-assembly silica/graphene oxide onto carbon fiber surface for enhance interfacial strength of epoxy composites

Incorporating nano-scale reinforcements onto carbon fiber (CF) surface is a promising approach to enhance the interfacial strength of epoxy composites. Herein, a hierarchical reinforcement (CF/SiO2/GO) was prepared through deposition silica (SiO2) and graphene (GO) onto CF surface by Layer-by-Layer electrostatic self-assembly (ESA) for the first time. The experimental results confirmed that the SiO2 and GO were successfully assembly, and scanning electron microscopy (SEM) indicated a uniformly coverage on the CF surface. After assembly with SiO2/GO of CF showed the surface roughness and wettability of CF increase obvious, which supplying strong mechanical interlocking between fiber and resin. Meanwhile, the interlaminar shear strength (ILSS) of CF/SiO2/GO epoxy composites were 46.3% higher than Untreated-CF composites.

A Review on Effect of Nanoreinforcement on Mechanical Properties of Polymer Nanocomposites

Polymer nanocomposites represent a new class of materials that offer an alternative to the conventional filled polymers. In this new class of materials, nanosized reinforcement are dispersed in polymer matrix offering tremendous improvement in performance properties of the polymer. The combination of nanoscale reinforcement and polymer matrix possess outstanding properties and functional performance which play an important role in many field of applications. This review addresses the types of nanoscale materials reinforced in polymer matrix such as nanocellulose, carbon nanotubes (CNTs), graphene, nanofibers and nanoclay followed by the discussion on the effect of these nanoscale reinforcement on mechanical properties of polymer nanocomposites. Besides, the potential use of polymer nanocomposite reinforced with those nanoscale reinforcements in various field of applications also discussed.

Comparison of Mechanical Reinforcement Effects of Cellulose Nanofibers and Montmorillonite in Starch Composite

Both cellulose nanofibers (CNF) and montmorillonites (MMT) are nanoscale reinforcement fillers that have shown reinforcing effects in polymer nanocomposites. CNFs belong to one‐dimensional nanofibers while MMT is part of two‐dimensional clay platelets, which show difference in shape, size, and composition. This study systematically compares their morphology and dispersion properties in a corn starch (CS) matrix, interactions with the matrix, and the resulting reinforcing effects on the CS matrix. Transparent CS/CNF and CS/MMT nanocomposites comprising up to 7 wt% nanofillers are obtained via solution casting. Fourier transform infrared (FTIR) spectroscopy, X‐ray diffraction (XRD), Scanning Electron Microscope (SEM), and tensile testing, thermogravimetry analysis (TGA), moisture uptake (Mu), and light transmittance (Tr) are used to examine the above‐mentioned properties of CS composites. It is found that the tensile properties, optical transparency, and water barrier properties of CS films are significantly improved whether adding a certain amount of CNF or MMT. However, the tensile strength increment of CS composites reinforced with CNF is slightly higher than that of MMT‐reinforced CS composites due to higher aspect ratio of CNF. From the results, it can be concluded that CNF is highly compatible with starch and can reinforce the starch phase efficiently to prepare green nanocomposite films.

Synergistic effect of graphene and carbon nanotubes on mechanical and thermal performance of polystyrene

Polystyrene has found wide variety of applications in mechanical and structural engineering fields, owing to its highly desirable physical properties. One of the key goals of researchers all over the globe is to improve the mechanical properties of polystyrene through reinforcement with nanoscale materials. The improvement in mechanical properties will in turn, increase the scope of utilization of polystyrene in many advanced mechanical applications. New generation carbon materials like carbon nanotubes and graphene have been proven to possess excellent mechanical properties and hence can serve as excellent nanoscale reinforcement materials for polymers. Present manuscript, demonstrates a facile method to use carbon nanotube/graphene mixture to improve mechanical properties of polystyrene. Thin films of the polystyrene-carbon nanotube/graphene hybrids were prepared and characterized by differential scanning calorimetry and nanoindentation techniques. The nanohybrid displayed considerable enhancement in midpoint of glass transition temperature (Tg). Tg of the hybrid nano-composite was improved significantly, compared to pristine polystyrene samples. Considerable improvement in modulus and hardness was also observed after reinforcement, which in turn, enhances the scope of application of polystyrene in advanced mechanical applications.

Non-intertwined graphitic domains leads to super strong and tough continuous 1D nanostructures

A systematic study on mechanics of carbon nanofibers (CNF) in relation to their microstructure is presented. The CNFs were fabricated via pyrolysis of polymeric nanofibers. In order to develop super-strong and super-tough one-dimensional nanomaterials, processing steps were aimed at reducing defects, e.g., poor graphitic alignment. The degree of graphitization was optimally controlled to benefit from strong sp2 C-C bonds while avoiding strength-compromising interactions between graphitic domains. The peculiar feature in CNFs was the discontinuity and rather uniform dispersion of turbostratic domains within the amorphous carbon, an apparent cause of crack pinning, and crack path deflection, thus strengthening/toughening. Hence, our CNFs exhibited superior strength compared to other emerging high-performance continuous fibers, such as CNT and graphene fibers. The best processing condition led to record high average strength of 6.3 ± 0.8 GPa (7.7 GPa maximum), 66% higher than previous reports. Moreover and contrary to most engineering materials, the high strength was achieved at no cost to ductility. The CNF exhibited significant ductility of 3.0 ± 0.7%, with energy-to-failure as high as 86 J/g, the highest reported for graphitic fibers. The research on simultaneously strong and tough CNF provides a promising pathway to develop the next generation of nanoscale reinforcements for lightweight and safety-critical structural applications.

Scalable manufacturing of ultra-strong magnesium nanocomposites

Magnesium, the lightest structure metal, is suitable for wide range of applications in various industries such as transportation. However, it suffers from moderate mechanical properties such as strength. Strengthening magnesium beyond what conventional strengthening approaches offer is of a significance interest. Incorporation of suitable nanoparticles into magnesium can effectively improve its mechanical properties. However, manufacturing of magnesium with populous dispersed nanoparticles remains as a great challenge. Here we report a novel liquid processing of magnesium nanocomposites with titanium carbide as the nanoscale reinforcement. Nanoparticles are uniformly dispersed in the magnesium, resulting in a significantly improved Vickers hardness of 143.5 ± 11.5HV.

Evaluation of the Reinforcement Efficiency of Low-Cost Graphite Nanomaterials in High-Performance Concrete

Low-cost nanomaterials (graphite nanoplatelet and carbon nanofiber) offer many of the highly desired mechanical, physical, geometric and stability characteristics of carbon nanotubes at substantially reduced cost. Experimental studies were implemented in order to evaluate the complementary effects of low-cost graphite nanomaterials and (micro-scale) polyvinyl alcohol fibers in high-performance concrete. Experimental results highlighted the balanced gains in diverse engineering properties of high-performance concrete realized by introduction of graphite nanomaterials. Desired levels of micro- and nano-scale reinforcement systems were identified. Experimental results pointed at synergistic effects of nano-and micro-scale reinforcement in concrete, which could be attributed to their actions at different scales. Graphite nanomaterials were found to significantly control the rate and extend of moisture sorption into concrete. The planar geometry of graphite nanoplatelets makes them more effective than carbon nanofibers in enhancing the moisture barrier qualities of concrete.

Effect of phosphoric acid on the morphology and tensile properties of halloysite-polyurethane composites

Abstract The high aspect ratio of nanoscale reinforcements enhances the tensile properties of pure polymer matrix. The composites were first made by adding halloysite nanotubes (HNTs) at low weight percentages of 1, 2, and 3 wt% to thermoplastic polyurethane (TPU). Then, HNTs were phosphoric acid-treated before adding to TPU at same weight percentage to create phosphoric acid HNTs-TPU composites. The samples were fabricated using injection moulding. The HNTs-TPU composites were characterized according to the tensile properties including tensile strength, tensile strain and Young’s modulus. The loading has shown its highest tensile values at 2 wt% HNTs loading and same findings are shown with the samples that treated with phosphoric acid. The tensile strength increased to reach 24.65 MPa compare with the 17.7 MPa of the neat TPU showing about 26% improvement. For the phosphoric acid-treated composites, the improvement has reached 35% compared to the neat sample. Regarding the tensile stain, the improvement was about 83% at 2 wt% HNTs loading. For Young’s modulus, the results obtained in this study have shown that Young’s modulus is linearly improved with either the loading content or the phosphoric acid treated achieving its highest values at 3 wt% HNTs of 14.53 MPa and 16.27 MPa for untreated and treated, respectively. FESEM results showed that HNTs were well dispersed in TPU matrix. Thus, HNTs-TPU has improved tensile properties compared with pure TPU due to the addition of nanofiller.