Surface Of Graphene Nanoplatelets Research Articles

Uncovering the thermal conductivity of graphene nanoplatelet composites with interlayer by a Monte Carlo model

Abstract This paper uses Monte Carlo (MC) method to study the thermal conductivity of graphene nanoplatelet (GNP) composites. Firstly, a large number of GNPs are randomly set in a representative volume element (RVE). Then, based on the temperature field satisfying the Laplace equation in the matrix, a coated surface (CS) is set up on each GNP surface, and the temperature of CS and GNP are obtained by a Walk-on-Spheres (WoS) method. Finally, the WoS method continues to be applied to calculate the heat flux density of composite materials, further obtaining the thermal conductivity of the composite. We have incorporated the influence of interlayers in the WoS process and pointed out that walk onto the interlayer surface have a very low probability of getting to GNP due to the extremely low thermal conductivity of the interlayer. The calculated results are consistent with the experimental data. The model also studied the effects of size, orientation, and aggregation of GNP on the thermal conductivity of the composite.

Nanosecond laser micromachining of graphene nanoplatelets reinforced ZK60 matrix composites

AbstractIn this paper, a nanosecond laser was used to etch the surface of graphene nanoplatelets reinforced ZK60 (GNPs/ZK60) matrix composites, and the effects of different scanning speeds, pulse repetition frequency and laser power on the etched morphology of the machined surface were investigated. The experimental results show that the etched groove width and heat affected zone width of GNPs/ZK60 composites are significantly increased compared with ZK60 material due to the influence of graphene, and the growth rate of the difference in heat affected zone width between GNPs/ZK60 composites and ZK60 materials is most significantly affected by the pulse repetition frequency. In addition, the dross height increases with the increase of laser power, while the scaly dross structure becomes increasingly clear.

Enhancing anticorrosive performance of epoxy-based coatings using magnetite/graphene hybrids modified with ionic liquids

Hybrid materials based on magnetite (Fe3O4) and graphene nanoplatelets (GNP) were prepared by the in situ co-precipitation synthesis of Fe3O4 in the presence of GNP aqueous dispersion. Alkyl-phosphonium–based ionic liquids bearing bromide (IL102) and diethyl phosphate (IL169) as the counter-anions were used for the first time to improve the dispersion of GNP. The successful preparation of the hybrids and the final incorporation of the ILs in the hybrids were confirmed by thermogravimetric analysis (TGA) and Fourier transform infrared (FTIR) spectroscopy. The exfoliation of the GNP sheets and the incorporation of Fe3O4 particles on the GNP surface were confirmed by transmission electron microscopy. The effect of different hybrids on the corrosion resistance of the epoxy coatings was evaluated in saline medium using by electrochemical impedance spectroscopy (EIS). Hybrids prepared by the in situ synthesis of magnetite (Mag@GNP) promoted better corrosion resistance than pure magnetite or those hybrids introduced into the epoxy coatings by physical blends, due to better dispersion of the former fillers into the epoxy matrix. The best anti-corrosion response was achieved using 5 % of Mag@GNP 102 due to the better filler dispersion and higher amount of incorporated ionic liquid in the system, which can act as inhibition agent for the corrosion process.

Flexible piezo-resistive strain sensors using all-polydimethylsiloxane based hybrid nanocomposites for wearable electronics.

We report flexible piezo-resistive strain sensors composed of silver nanoparticle (Ag NP), graphene nanoplatelet (GNP), and multi walled carbon nanotube (MWCNT)-based ternary conductive hybrid nanocomposites as an active sensing layer fabricated using a simple solution processing method on flexible polydimethylsiloxane (PDMS) substrates. The electrical characteristics have been studied in PDMS-based flexible devices having three different kinds of structures, namely Ag NPs/MWCNT/PDMS, GNP/PDMS and Ag NPs/GNP/PDMS. The microscopic analysis of the hybrid nanocomposites is undertaken using field emission scanning electron microscopy. The diameter of the CNTs is found to be in the range of 20-40 nm, whereas the length is determined to be 100-800 nm. The average diameter and length of the GNPs are observed to be 30-50 nm and 100-500 nm, respectively. The crystallite size of the silver nanoparticles in the Ag NPs/MWCNT/PDMS and Ag NPs/GNP/PDMS-based nanocomposites is determined to be 22.8 nm and 29.1 nm, respectively. The prepared sample of Ag NPs shows four distinct peaks in the X-ray diffraction pattern, which correspond to the (111), (200), (220), and (311) face-centered cubic (FCC) crystalline planes. Raman spectroscopy is undertaken to study the fundamental physical properties and chemical analysis of the nanocomposites. Ag NPs/GNP/PDMS-based sensors exhibit superior performance in terms of sensitivity, response and recovery time during breathing/unbreathing analysis. The large surface area of the Ag NPs and GNPs promotes uniform distribution of Ag NPs to fill into the porous GNP surface, thereby facilitating high contact area along with better electron transport in the Ag NPs/GNP/PDMS hybrid nanocomposite-based sensors. The gauge factor (GF), response and recovery time of the Ag NPs/GNP/PDMS hybrid nanocomposite-based sensors are determined to be 221, 130 ms and 119 ms, respectively. The ternary conductive nanocomposite-based sensors are free from the drawbacks of binary nanocomposite-based sensors where the high percolation threshold and poor mechanical behaviour lead to the degradation of the device performance.

Trace nano-Ti addition for graphene nanoplatelets/copper composites to simultaneously enhance strength-ductility and wear resistance

Graphene nanoplatelets (GNPs)/copper composites containing nano-Ti addition were prepared using the vacuum hot-pressing sintering process. The effect of Nano-Ti on microstructure and mechanical properties of GNPs/copper composite was investigated. Before the sintering of the composite powders, the massive nano-Ti particles decorated on the GNPs surface. The GNPs/Ti chemical reaction occurred during the sintering, and then formed abundant TiC particles. Hardness and strength of bulk GNPs/copper composites were enhanced evidently by nano-Ti addition, which increased with nano-Ti increasing. The nano-Ti addition achieved simultaneous strength-ductility enhancement of GNPs/copper composites. The hardness, tensile yield strength, ultimate tensile strength and tensile elongation of the composite with 3.0 wt% nano-Ti addition demonstrated respectively 128.2 %, 199.6 %, 125.9 %, and 30.6 % enhancement comparing with no nano-Ti added sample. The nano Ti addition can effectively improve the wear resistance of GNPs/copper composites. The relevant structural formation, strengthening-toughening and wear mechanisms of GNPs/copper composites with nano-Ti addition were discussed.

Graphene Nanoplatelet Surface Modification for Rheological Properties Enhancement in Drilling Fluid Operations: A Review

Graphene Nanoplatelet Surface Modification for Rheological Properties Enhancement in Drilling Fluid Operations: A Review

Plasma modification of graphene nanoplatelets surfaces

Atmospheric plasma processing, which combines the efficacy of chemical processes and the safety of physical processes, has been used to modify the surface characteristics of graphite-based materials. In this work, two distinct plasma source gases, C4F8 and O2, with the addition of a rotary reactor were used. The effectiveness of modifying the basal plane of intercalated graphite nanoplatelets (GnP) was investigated with various analytical techniques and the visual observation of the dispersion of these plasma-treated GnP in solvents was also reported. It is shown that this low-temperature plasma processing technique can be used to successfully modify the GnP surface without significantly changing the intrinsic structure of the GnP, which is desirable in many applications. With the C4F8 plasma treatment, the immersion characteristics in solvents can be tuned and the functional groups present on the surface can be tailored to produce desired bonding environments. This surface chemistry tunability will provide the needed functionalities in creating graphene-containing composite materials.

A comprehensive experimental study of enhanced solid particle erosive resistance on the inner/outer surface of graphene nanoplatelets modified basalt/epoxy composite pipe

AbstractBasalt fiber reinforced polymer (BFRP) composite pipe is an excellent alternative to glass and carbon fiber reinforced composite pipes in industry and promising in high recycling for polymer composite used in aerospace, marine, and automotive. To enhance the solid particle erosion (SPE) properties of filament‐wound BFRP composite pipe while preserving its mechanical properties, reinforced BFRP composite pipes were prepared to employ non‐functionalized graphene nanoplatelets (GnPs) at a reinforcement concentration of 0.25 wt.% and ultrasonication mixing technique. The SPE behavior of GnPs reinforced and non‐reinforced BFRP composite pipes were characterized by axial and radial positioning of the inner and outer surfaces of the pipes. In each case, the erosion rates of these composite pipes were evaluated at five impingement angles (30°, 45°, 60°, 75°, and 90°) and an impact velocity of 34 m/s. The erosion response of both BFRP composite pipes' outer surfaces showed a semi‐ductile in the axial positioning, with a maximum erosion rate at a 60° impingement angle. However, these composite pipes' inner surfaces in the same positioning presented a maximum erosion rate at a 45° impingement angle. Besides, it is explored that the GnPs contribute to an improvement of approximately 10%–55% in erosive wear resistance of the non‐reinforced BFRP composite pipes. The damage analysis of eroded surfaces was examined through scanning electron microscopy (SEM), and the GnPs effect upon composite pipes' erosion micromechanisms was presented and discussed in detail.Highlights GnPs increased the BFRP composite pipe's erosion resistance. Erosion rate on the inner surface increases due to particle accumulation. GnPs improved erosion behavior via solid lubrication and mechanical properties.

Magnetite deposit on graphene nanoplatelets Surface: An assessment of grafting parameters

Graphene has emerged as an exceptional material for industrial usage and has widely been implemented. In this regard, the current study examines the enhanced characteristics of graphene nanoplatelets (GNP) by depositing the magnetite iron oxide (Fe 3 O 4 ) on its surface. Ethylene glycol solvent was taken in Fe 3 O 4 and GNP samples formation which were synthesized by the time parameter at various intervals. The Physicochemical characterizations were carried out by FTIR, XPS, XRD, and FESEM. It was observed that the successful grafting of iron particles on the GNP surface was achieved at a high time interval, and the results were more significant. FESEM images reveal a spherical structure on the surface of the graphene nanoplatelets in the GG 1, GG 2, and GG 4 sample. Fe 3 O 4 has an irregular morphology with pores observed on the surface of GNP. However, the surface morphology of the graphene changes to a crinkled and rough surface.

Anomalously enhanced subcooled flow boiling in superhydrophobic graphene-nanoplatelets-coated microchannels

In boiling heat transfer, superhydrophobic surface is deemed to reduce the critical heat flux (CHF) due to the immediate formation of an insulating vapor film that inhibits effective heat transfer despite its smaller energy barrier for bubble nucleation than that of a superhydrophilic surface. Here, a subcooled flow boiling investigation is carried out in a microchannel heat sink at a low mass flux condition using the superhydrophilic and superhydrophobic graphene nanoplatelets (GNPs) composite coatings. Interestingly, the flow boiling performance of the superhydrophobic GNPs-coated microchannel significantly transcends that of its superhydrophilic counterpart. By benchmarking with the performance of an uncoated microchannel, the CHF and heat transfer coefficient of the superhydrophobic GNPs-coated microchannel are enhanced up to 134% and 135%, respectively. This anomaly is ascribed to the Cassie Baxter-to-Wenzel transition on the superhydrophobic GNPs-coated surface, which is infiltrated with liquid, restricting the nucleating bubbles from expanding into a vapor film and sustaining an efficient boiling. The initial Wenzel state of the superhydrophobic GNPs surface is primarily ascribed to the rapid intercalation of water molecules via the unique graphene nanostructure. This study sheds new light on the unique wetting behavior of graphene-nanostructured surfaces in the context of microscale flow boiling heat transfer.

A multispectroscopic approach for ultra-trace sensing of prostate specific antigen (PSA) by iron nanocomposite fabricated on graphene nanoplatelet

Herein we report an easy, rapid and cost-effective method for spectroscopic sensing of a prostate cancer biomarker prostate specific antigen (PSA) using a novel nanocomposite. The material is a synthetic quinoxaline derivative-based iron nanocomposite fabricated on graphene nanoplatelet surface (1d-Fe-Gr). Presence of graphene enhanced the efficacy of synthesized 1d-Fe-Gr to sense PSA in serum medium with an impressive limit of detection (LOD) value of 0.878 pg/mL compared to 1d-Fe alone (LOD 17.619 pg/mL) using UV–visible absorption spectroscopy. LOD of PSA by 1d-Fe-Gr using Raman spectroscopy is even more impressive (0.410 pg/mL). Moreover, presence of interfering biomolecules like glucose, cholesterol, bilirubin and insulin in serum improves the detection threshold significantly in presence of 1d-Fe-Gr which otherwise cause LOD values of PSA to elevate in control sets. In presence of these biomolecules, the LOD values improve significantly as compared to healthy conditions in the range 0.623–3.499 pg/mL. Thus, this proposed detection method could also be applied efficiently to the patients suffering from different pathophysiological disorders. These biomolecules may also be added externally during analyses to improve the sensing ability. Fluorescence, Raman and circular dichroism spectroscopy were used to study the underlying mechanism of PSA sensing by 1d-Fe-Gr. Molecular docking studies confirm the selective interaction of 1d-Fe-Gr with PSA over other cancer biomarkers.

Green Synthesis of Fe/Graphene Nanocomposite Using Cleistocalyx operculatus Leaf Extract as a Reducing Agent: Removal of Pollutants (RhB Dye and Cr6+ Ions) in Aqueous Media

AbstractIndustrial wastewater contains many compounds that pollute the environment, which have a strong impact on humans and the ecosystem. Zero‐valent iron nanoparticles (nZVI) are materials with the potential to treat many wastes released into the aquatic environment. nZVI was synthesized via a green method using Cleistocalyx operculatus (CO) leaf extract as a reducing agent. Among them, graphene nanoplatelets (GNPs) were used as support materials to enhance the reduction capacity and stability of nZVI. The morphology, structure, and crystallinity of the nZVI@GNPs nanocomposite were demonstrated through scanning electron microscopy (SEM), X‐ray diffraction (XRD), Energy Dispersive X‐Ray Spectroscopy (EDS), and Fourier Transform Infrared (FTIR). Zero‐valent iron nanoparticles following an optimized process for spherical particles with particle sizes ranging from 30–100 nm, uniformly distributed on the surface of GNPs. The removal performance of RhB and Chromium (VI) ions by the nZVI@GNPs composite was evaluated through Ultraviolet‐Visible Spectroscopy (UV‐Vis). The results show that nZVI/GNPs can remove RhB and Cr6+ more than 98 % after 30 minutes of treatment. The affecting factors on the treatment process, such as pH, reaction time, and amount of material, were also studied.

CuI@graphene as antibody-free fluorosensor for prostate-specific antigen (PSA)

In this study, a hassle- free, rapid, and green synthesis of a novel fluorosensor CuI@graphene nanocomposite (CuI@Gr) is described for antibody-free optical sensing of prostate- specific antigen (PSA), a biomarker of prostate cancer. Herein, we report enhanced efficacy of the prepared CuI@Gr nanoparticles by fabricating the surface of graphene nanoplatelets with CuI to sense PSA in serum medium using fluorescence spectroscopy with a ten-fold lower limit of detection (LOD) value as 0.331 pg/mL as compared to CuI nanoparticles with a linear range of detection 0.5–5 pg/mL. Moreover, CuI@Gr nanoparticles were found to have higher efficacy in the detection of PSA in the presence of 10 mM concentrations of individual interfering biomolecules such as glucose and cholesterol, which are present in serum due to different comorbidities such as diabetes or hypercholesterolemia. Significant improvement in the LOD values was obtained in case of comorbidities as compared to the normal condition with LOD values ranging from 0.189–0.331 pg/mL. Hence, our low-cost fluorosensor makes this detection method a sensitive as well as a specific one for the clinical diagnosis of patients having prostate cancer even having other pathophysiological conditions.

Solvothermal synthesis and enhancement of microstructural and magnetic properties of G-AgFe3O4 nanocomposites

ABSTRACT Metal-decorated carbon substrates such as carbon nanotubes, graphene nanoplatelets and carbon nanoparticles have been of great interest to the scientific community for the last three decades due to their numerous potential applications. Chemical species, both organic and inorganic molecules, can be attached to the surface of graphene nanoplatelets (GNPs). G-AgFe3O4 nanocomposites were synthesised by solvothermal method, and scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FT-IR) and Raman spectroscopy were used to determine the properties of the composite. It was revealed that plenty of AgFe3O4 particles are well distributed on graphene nanoplatelets’ surface. The Vibrating Sample Magnetometer (VSM) result shows the ferromagnetic behaviour of the composite at ambient temperature. The ternary of G-AgFe3O4 nanocomposite would be useful in modern electronic industries such as magnetic sensors and digital signal processors. On the other hand, it will be auspicious in biological and environmental fields based on the good magnetic properties.

Nanotextured surfaces with enhanced ice-traction and wear-resistance

Elastomers are the main material component for footwear and tires contact applications. However, they exhibit low traction on wet ice, resulting in slips and falls for individuals and vehicles during wintertime. Textured elastomeric short fiber composites can be manufactured in a scalable manner with conventional processing techniques such as injection molding, and have promising wet ice slip resistance behavior. However, the state-of-the-art textured composite approaches employs one-dimensional (1D) micron-scale fibers that are prone to mechanical abrasion on hard surfaces, resulting in their ice traction decay over time. Here, we demonstrate a novel microstructural design strategy for developing durable slip-resistant composites using nanomaterials. To this aim, a series of micron- and nanoscale 1D and 2D fibers as additives in the textured elastomers are evaluated for surface morphology, ice-traction, and wear-resistance. We show that unlike 1D and other 2D counterparts, hexagonal graphene nanoplatelets (GNP) exhibit superior wear-resistance and an anomalous wear-induced increase in ice-traction functionality. Specifically, the partially agglomerated morphology of the GNP surfaces results in a hierarchical surface texturing, which imparts the surface with a 64% ice traction improvement (0.46 ± 0.11; p < 0.0001) at a low surface weight loss (2.44 mg cm−2). This study provides new microstructural design pathways for designing durable non-slip composites and can shed light on new applications for the diverse class of 2D nanomaterials.

Influence of graphene nanoplatelets geometrical characteristics on the properties of polylactic acid composites

The influence of graphene nanoplatelets (GNP) surface area and size on the dispersion, electrical percolation behavior, electrical conductivity, thermal conductivity, electromagnetic interference (EMI) attenuation, and EMI attenuation mechanisms of GNP/polylactic acid (PLA) were investigated. The GNP/PLA composite's electrical percolation threshold decreased with the increase in GNP surface area and decrease in GNP size. The higher number of GNP particles associated with the decrease in GNP size and increase in GNP surface area facilitated the creation of a conductive network at a lower GNP content. However, at a GNP loading of 30 wt%, the GNP/PLA composites' electrical, EMI SE, and thermal conductivity decreased with the increase in GNP surface area and decrease in GNP size. At high nanofiller loading, the contact resistance between the nanofiller particles is more important than the nanofiller aspect ratio or size. The smaller filler size means more particles and more filler/filler resistance points. The most exciting finding is the dependence of EMI attenuation mechanisms on the GNP surface area. EMI attenuation by absorption was found to increase with the increase in GNP surface area.

Highly improved mechanical and thermal properties of alkali silicate and graphene nanoplatelet composite adhesives

Inorganic adhesives have received increased attention due to their high temperature resistance, non-toxicity, and environment friendliness. However, poor adhesion strength of inorganic adhesives hinders their application. Further, graphene improves the mechanical and thermal properties of polymer composites. Herein, graphene nanoplatelets (GNP) with different specific surface areas were added into a mixed silicate (MS) containing different ratios of alkali silicates. The results revealed that lap shear strengths increased from 7.4 MPa with the unmodified MS to 9.42 MPa with the MS/GNP 750_10% composite. In addition, the GNP powder with the highest surface area (MS/GNP 750_10% composite) formed maximum interfaces with the silicate matrix, leading to effective load transfer and reduction in stress concentration sites. Hardness and modulus increased as the GNP surface area increased; unmodified MS had the highest values because GNP changed MS from brittle to ductile. In addition, at room temperature, thermal conductivity increased by 60% in the vertical direction and 173% in the horizontal direction in the MS/GNP 750_10% composite compared to the unmodified MS. Furthermore, at a higher temperature (100 °C), the thermal conductivity of the MS/GNP 750_10% composite increased by 273% in the vertical direction and 412% in the horizontal direction. • This study investigated the effect of the surface area of GNP powder on the properties of Alkali silicate based adhesives. • The lap shear strength increased from 7.4 MPa in the bare MS to 9.42 MPa in the MS/GNP 750_10%. • The thermal conductivity increased by 60% in the vertical and 173% in the horizontal direction in the MS/GNP 750_10%.

Characterization of graphene nanoplatelets reinforced sustainable thermoplastic elastomers

Elastomer nanocomposites have attracted tremendous attention in recent years owing to their exceptional mechanical, electrical, thermal barrier and flame-retardant properties. Graphene has become a prevalent constituent in elastomer nanocomposites thanks to its superior stiffness and strength, as well as its potential to enhance multifunctional properties. In this study, sustainable thermoplastic elastomers based on recycled polypropylene (RPP) and renewable guayule latex, which has recently entered the commercial arena as an alternative natural rubber, were prepared with polypropylene-grafted-maleic anhydride as a coupling agent. Graphene nanoplatelets (GnP) (2.5–10% by wt.) were added to enhance the mechanical (strength and modulus), thermal and flame retardant properties. With the addition of 10% GnP, the flexural modulus increased by a factor of 1.24, whereas tensile modulus increased by 76%. Scanning electron microscopy of the fractured surface of GnP reinforced nanocomposites showed a good correlation with the improvements in impact properties. Thermogravimetric analysis of composites with 10% GnP showed an increase in carbon residue at 600°C by a factor of 3.4 indicating improved thermal stability. Incorporation of GnP did not have a significant effect on the glass transition temperature range, however, the magnitude of storage modulus increased significantly. As expected, incorporation of GnP increased the shear viscosity, which decreased with shear rate exhibiting non-Newtonian behavior. These results indicate that GnP reinforced composites could be used in the next generation of automotive thermoplastic elastomer products such as cowl vent grills, wheel lips, rear bumper fascia, rocker panels and side moldings with certain improvements in mechanical, thermal and physical properties.

Rheological properties of SBS modified asphalt incorporated polyvinylpyrrolidone stabilized graphene nanoplatelets

With the rapid development and application of nanomaterials in recent years, graphene nanoplatelets (GNPs) compounded styrene–butadienestyrene (SBS) to prepare novel asphalt binders with superior high-temperature performance and outstanding mechanical property, have gradually become a hot topic. However, this approach may result in poor compatibility of GNPs with SBS modified asphalt. In this work, the loosely layered composite, polyvinylpyrrolidone stabilized graphene nanoplatelets (PVP-GNPs), has been prepared with a polymer, polyvinylpyrrolidone (PVP), adsorbed onto the surface of graphene nanoplatelets through non-covalent interactions. Subsequently, the prepared PVP-GNPs as a modifier was added into SBS modified asphalt to increase the compatibility with the asphalt binder. The conventional experiment results revealed that the addition of a certain amount of PVP-GNPs improved the softening point and temperature sensitivity. Meanwhile, dynamic rheological tests (Dynamic Shear Rheometer (DSR), Multiple Stress Creep Recovery (MSCR), Linear Amplitude Sweep (LAS), and Bending Beam Rheometer (BBR)) showed an enhancement of the viscoelastic properties, high-temperature rutting resistance, medium-temperature fatigue damage tolerance, and low-temperature thermal cracking resistance. X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, and scanning electron microscopy (SEM) techniques demonstrated the successful attaching of PVP onto the surface of GNPs, which expanded the spatial distance of GNPs and facilitated the intercalation of asphalt molecules. Moreover, 1.0%–1.5% was recommended as the optimal dosage of PVP-GNPs for modification. This study may shed light on the application of GNPs to asphalt pavements.

Nacre-like GNP/Epoxy composites: Reinforcement efficiency vis-à-vis graphene content

Nanocomposites based on the biomimetic brick and mortar architecture are gathering great attention recently due to the outstanding properties of the natural analogues. Thanks to the very high in-plane orientation of nanoplatelets and the low matrix content, these materials exhibit good mechanical performance combined with excellent functional properties based on the nanoplatelets characteristics. Key feature of these materials is the presence of a regular nanostructure that consists of alternated nanoplatelet and matrix layers. Such architecture is commonly attained by means of bottom-up manufacturing processes able to control the alternation of the two phases at the nanoscale. This differs markedly from the top-down manufacturing processes, which are suitable for an industrial scale up but fail to meet the expected requirements. In the present work, nacre-like graphene nanoplatelets (GNPs)/epoxy films at different filler content have been prepared by a top-down manufacturing technology and their mechanical properties in tension have been experimentally evaluated. The elastic modulus has been found to exhibit a maximum between 53 and 67 vol% filler content and then it starts dropping at higher loadings. This was attributed to the depletion of the polymeric matrix which disrupts the continuity of the matrix layer thus inducing incomplete GNP surface coverage. As a result, the effective area for stress-transfer is considerably reduced and this impairs the reinforcement efficiency. In order to explain this behaviour, a model is proposed for predicting the stress transfer characteristics in brick and mortar systems by paying attention to possible non-uniform matrix distribution over the nanoplatelets. The proposed analysis captures well the observed effects and paves the way for the development and further improvement of this new class of engineering materials.