Functionalized Graphene Oxide Sheets Research Articles

Thin Polyamide Layer Cross-Linked Graphene-Oxide based Ceramic Membranes for Efficient Separation of the Surfactant Stabilized Oil-In-Water Emulsions

Thin Polyamide Layer Cross-Linked Graphene-Oxide based Ceramic Membranes for Efficient Separation of the Surfactant Stabilized Oil-In-Water Emulsions

Clinical potential of plasma-functionalized graphene oxide ultrathin sheets for bone and blood vessel regeneration: Insights from cellular and animal models

Graphene and graphene oxide (GO), due to their unique chemical and physical properties, possess biochemical characteristics that can trigger intercellular signals promoting tissue regeneration. Clinical applications of thin GO-derived sheets have inspired the development of various tissue regeneration and repair approaches. In this study, we demonstrate that ultrathin sheets of plasma-functionalized and reduced GO, with the oxygen content ranging from 3.2 % to 22 % and the nitrogen content from 0 % to 8.3 %, retain their essential mechanical and molecular integrity, and exhibit robust potential for regenerating bone tissue and blood vessels across multiple cellular and animal models. Initially, we observed the growth of blood vessels and bone tissue in vitro using these functionalized GO sheets on human adipose-derived mesenchymal stem cells and umbilical vein endothelial cells. Remarkably, our study indicates a 2.5-fold increase in mineralization and two-fold increase in tubule formation even in media lacking osteogenic and angiogenic supplements. Subsequently, we observed the initiation, conduction, and formation of bone and blood vessels in a rat tibial osteotomy model, evident from a marked 4-fold increase in the volume of low radio-opacity bone tissue and a significant elevation in connectivity density, all without the use of stem cells or growth factors. Finally, we validated these findings in a mouse critical-size calvarial defect model (33 % higher healing rate) and a rat skin lesion model (up to 2.5-fold increase in the number of blood vessels, and 35 % increase in blood vessels diameter). This study elucidates the pro-osteogenic and pro-angiogenic properties of both pristine and plasma-treated GO ultrathin films. These properties suggest their significant potential for clinical applications, and as valuable biomaterials for investigating fundamental aspects of bone and blood vessel regeneration.

Rational Design of a Graphene Oxide–Coated Separator for Thermally and Mechanically Stable Li Metal Anode

Lithium-ion (Li-ion) batteries are widely used in high-performance energy storage applications because of their high energy density. However, safety concerns related to thermal runaway remain a significant challenge for Li-ion batteries. Electrolyte leakage and dendrite formation can trigger thermal runaway, and these factors typically damage traditional polyethylene (PE) separators. Consequently, these separators struggle under extreme conditions and fail to control dendrite growth. In this study, we proposed a solution by coating PE separators with graphene oxide (GO) layers. GO, as a ceramic material, provides superior thermal and mechanical stability compared with polymers. Moreover, GO-coated PE separators (GO-S) do not compromise the advantages of PE separators and effectively manage dendrite growth. In this study, the as-prepared GO-S exhibits excellent electrochemical properties in terms of high ionic conductivity, suppression of Li dendrite growth during charge/discharge process, and long-term cyclability for 7,000 h (3,500 cycles) as well as high thermal stability even after heat treatment of 100°C. Thus, we expect that this research can highlight the potential application of functionalized GO sheets in addressing the thermal and mechanical limitations of polymer-based separators, thereby enhancing the safety and reliability of Li-ion batteries.

Fabrication of Inorganic Coatings Incorporated with Functionalized Graphene Oxide Nanosheets for Improving Fire Retardancy of Wooden Substrates.

Flame-retardant chemicals are frequently used within consumer products and can even be employed as a treatment on the surface of different types of materials (e.g., wood, steel, and textiles) to prevent fire or limit the rapid spread of flames. Functionalized graphene oxide (FGO) nanosheets are a promising construction coating nanomaterial that can be blended with sodium metasilicate and gypsum to reduce the flammability of construction buildings. In this work, we designed and fabricated novel and halogen-free FGO sheets using the modified Hummers method; and subsequently functionalized them by pentaerythritol through a chemical impregnation process before dispersing them within the construction coating. Scanning electron microscopic images confirm that the FGO-filled coating was uniformly dispersed on the surface of wooden substrates. We identified that the FGO content is a critical factor affecting the fire retardancy. Thermogravimetric analysis of the FGO coating revealed that higher char residue can be obtained at 700 °C. Based on the differential scanning calorimetry, the exothermic peak contained a temperature delay in the presence of FGO sheets, primarily due to the formation of a thermal barrier. Such a significant improvement in the flame retardancy confirms that the FGO nanosheets are superior nanomaterials to be employed as a flame-retardant construction coating nanomaterial for improving thermal management within buildings.

Amine-amide functionalized graphene oxide sheets as bifunctional adsorbent for the removal of polar organic pollutants

Effective mitigation of polar organic impurities from industrial effluents is a global environmental challenge. Here, we describe the solvothermal synthesis of ammonia-functionalized graphene oxide (NH3GO) sheets for adsorptive removal of diverse organic pollutants, such as cationic dye basic blue 41 (BB41), anionic dye methyl orange (MO), and ionic 4-nitrophenol (4-NP), in aqueous media. Structural analysis of NH3GO suggest a potent role of surface acidic and basic binding sites in adsorption of targets through an interplay of dynamic experimental variables, e.g., contact time, pH, initial adsorbate concentration, adsorbent mass, and temperature. At an initial pollutant concentration of 20 mg/L, equilibrium adsorption capacities for BB41, MO, and 4-NP were estimated at 199.5, 64.0, and 54.1 mg/g, respectively, with corresponding partition coefficients of 4156, 79.4, and 14.3 L/g, respectively. Experimental data of all three organic pollutants are best fitted by the pseudo-second-order kinetic model. The adsorption isotherm of BB41 follows a multilayer adsorption pattern, while those of MO and 4-NP fit into a monolayer adsorption pattern. The endothermic and spontaneous nature of the adsorption processes has also been explored for the three targets on NH3GO based on thermodynamic analysis. The prepared NH3GO sheets appear to be a promising adsorbent for the removal of polar organic dyes and aromatics in the solution phase.

Surface Functionalization of Graphene Oxide with Polymer Brushes for Improving Thermal Properties of the Polymer Matrix

In this work, polymethyl methacrylate (PMMA) and polystyrene (PS) with controlled structures would be grafted on graphene material. The hybrid materials were prepared by coating graphene oxide (GO) with polydopamine (PDA) as a reactive underlayer and reducing agent, subsequently, surface-initiated polymerization of monomers (methyl methacrylate, styrene) based on the activators regenerated electron transfer atom transfer radical polymerization (ARGET-ATRP) technique. The polymer brush-modified graphene materials were then incorporated into the PMMA or PS matrix to get polymer nanocomposites with better thermal properties. The results of Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and thermal gravimetric analysis (TGA) demonstrated that PMMA and PS chains were successfully anchored on the surfaces of functionalized GO sheets. The influence of the grafted polymer brush-modified GO on thermal stability of PMMA and PS was investigated by a simultaneous thermal analyzer. Thermal conductivity of the polymer nanocomposite was determined by a conductive calorimeter. The results showed that thermal stability, glass transition temperature ( T g ), and thermal conductivity of the polymer nanocomposites were obviously improved compared with pure PMMA or PS.

Self-assembled benzoic acid functionalized graphene oxide sheets with zinc (II) ions: Graphene oxide framework; novel material for environmental sensing application

A framework of graphene oxide (GOF) was obtained by self-assembly of benzoic acid functionalized graphene oxide (BFG) with Zn (II) ions via coordination chemistry. The crystalline morphology of the graphene oxide framework (GOF) was confirmed by X-ray diffraction analysis and transmission electron microscopy. The functionalization of graphene oxide and framework formation was confirmed using Raman and FT-IR spectroscopy while morphology of BFG and GOF was studied using scanning electron microscopy with elemental analysis. This newly synthesized GOF material is used for electrochemical oxidation of nitrophenol isomers such as 2-NP and 4-NP using cyclic voltammetry and differential pulse voltammetry on glassy carbon electrode (GOF/GC electrode). The GOF/GC electrode showed improved electrochemical behavior for nitrophenols oxidation as compared to graphene oxide modified glassy carbon electrode (GO/GC electrode) and bare GC electrode. The GOF based sensor was found to be highly sensitive with detection limit of 60 nM, for 2-NP and 96 nM for 4-NP, and their corresponding sensitivities were 8.35 µAµM−1cm−2 and 2.22 µAµM−1cm−2 respectively. The enhanced electrochemical detection of nitrophenols might have been resulted on GOF/GC electrode due to accumulation of these nitrophenols and for this the binding constant calculated using Langmuir isotherm equation are 29 × 103 M−1 (for 2-NP) and 46 × 103 M−1 (for 4-NP).

The correlated effects of polyetheramine-functionalized graphene oxide loading on the curing reaction and the mechanical properties of epoxy composites

In this study, the effects of polyetheramine (D230) functionalized graphene oxide loading on the curing reaction, thermal and mechanical properties of epoxy composites were studied and the correlation between structure and property of epoxy composite was established. In the functionalization of graphene oxide (GO), the effect of the mass ratio of D230 to GO on chemical properties of the functionalized GO was investigated. Results showed that D230 were successfully covalently grafted onto surface of two-dimensional functionalized GO sheet. The functionalized GO sheets prepared under optimal condition of D230/GO ratio of 1:1 dispersed evenly in epoxy composites, indicating the possibility of the epoxy composite fabrication by the solvent-free technique. The analysis of qualitative Cure Index suggested that epoxy composites were subjected to excellent curing. The quantitative evaluation of curing kinetics demonstrated that the functionalized GO exhibited a chemical facilitation on the curing reaction. However, the functionalized GO simultaneously physically restricted the curing reactivity, especially at high loading. These contributed to the improved interfacial properties and high toughness of the epoxy composites. Compared to neat epoxy, the epoxy composites showed effective tensile strength improvement of ∼10.0% (77.0 MPa), tensile modulus enhancement of ∼7.7% (3.34 GPa), flexural modulus increment of ∼12.1% (3.43 GPa), and flexural strength increment of ∼10.6% (124.3 MPa). This study demonstrated an effective and environment-friendly strategy to design GO reinforced epoxy composites with favorable dispersion and interfacial bonding, and it further clarified the relationship between the crosslinking network/interfacial structure and the mechanical properties of epoxy composites.

Tuning the interface in epoxy-based composites and laminates through epoxy grafted graphene oxide enhances mechanical properties.

Improved dispersion together with enhanced interfacial adhesion of the reinforcement is the key to superior structural properties in polymer nanocomposites. Herein, graphene oxide (GO) is employed to reinforce epoxy, and in order to improve the interfacial adhesion, epoxy chains were grafted directly onto GO prior to composite preparation. The functionalized GO sheets were systematically characterized using FTIR, TEM, Raman spectroscopy, XRD, and XPS. The epoxy composites with GO and epoxy grafted graphene oxide (Ep-g-GO) were prepared with the addition of only a small amount (0.5 wt%) of GO using a mechanical stirrer coupled to a bath sonicator. This strategy resulted in an impressive increase in mechanical properties, 40% in storage modulus, 70% in hardness, 39% in fracture toughness, and 8% in tensile strength, as compared to neat epoxy. In addition, the modified composites were thermally stable up to 300 °C as inferred from the thermogravimetric analysis. The enhanced properties of the composites further led to investigating the effect of Ep-g-GO on epoxy/carbon fiber (CF) laminates. Interestingly, incorporation of 0.5 wt% Ep-g-GO resulted in improved interfacial adhesion between GO and the epoxy matrix, which enhanced the tensile strength by 12% and inter-laminar shear strength by 9% as compared to neat epoxy/CF laminates. This study clearly demonstrates the positive effect of the tailored interface, offered by Ep-g-GO, on the mechanical properties of epoxy composites and epoxy/CF laminates.

Amine-Amide Functionalized Graphene Oxide Sheets as Bifunctional Adsorbent for the Removal of Polar Organic Pollutants

Amine-Amide Functionalized Graphene Oxide Sheets as Bifunctional Adsorbent for the Removal of Polar Organic Pollutants

Comparative studies on the adsorption of metal ions from aqueous solutions using various functionalized graphene oxide sheets as supported adsorbents

Graphene oxide (GO) was chemically modified by bis(2-pyridylmethyl)amino groups (BPED) through a multistep procedure. For comparison, and to justify the grafting of BPED groups onto the GO sheets, the GO-based material obtained after each step was used as a solid phase adsorbent for removing Cu(II), Ni(II) and Co(II) metal ions from aqueous solutions. The influence of metal ion concentrations, pH, contact time and temperature on their adsorption onto the GO-based adsorbents was investigated and the GO-EDA-CAC-BPED adsorbent showed the highest ability to adsorb Cu(II), Ni(II) and Co(II) with a concentration of 250 mg.L−1 at pH = 7. Additionally, it was demonstrated that the equilibrium adsorption capacities of these metal ions followed the order of Cu(II)>Ni(II)>Co(II) whatever the GO-based adsorbent. Moreover, to examine the underlying mechanism of the adsorption process, pseudo-first order, pseudo-second order, Elovich or Roginsky-Zeldovich and intraparticle diffusion models were fitted to experimental kinetic data. It was shown that the pseudo-second-order model was the most appropriate one to describe the adsorption of heavy metal ions by the GO-based materials. Finally, it was demonstrated that their desorption/regeneration capacities were higher than 10 cycles, opening the path to the removal of metal ions from wastewater solutions.

POSS-functionalized graphene oxide hybrids with improved dispersive and smoke-suppressive properties for epoxy flame-retardant application

Functionalized graphene oxide sheets (FGO) with improved dispersive and smoke-suppressive properties were synthesized by covalently grafting octa (propyl glycidyl ether) polyhedral oligomeric silsesquioxane on graphene oxide sheets (GO) with γ-aminopropyl triethoxysilane as a chemical bridge. The good dispersion of FGO sheets in the epoxy resin (EP) matrix endowed EP composites with stable thermal resistance, enhanced tensile and smoke-suppressive properties. Cone calorimeter tests indicated that the addition of 0.7 wt% FGO sheets to EP composites reduced the peak of heat release rate, total heat release, and total smoke release by 49.7%, 34.3%, and 41.5%, respectively. Two important effects that originated from FGO promoted this improvement; that is, well-dispersed FGO sheets exhibited a tortuous effect by lengthening the heat path and inhibiting heat diffusion in the EP matrix, and the increase in char residue and the reduction in gas volatiles confirmed the barrier effect of FGO sheets by forming protective char structures on the surface of the matrix, which restrained smoke release. This method provided a feasible concept for effectively enhancing the flame retardancy of EP composites by combining the characteristics of graphene and polyhedral oligosilsesquioxane through the construction of effective interfacial interactions.

Synthesis, characterization and electrochemical evaluation of a novel high performance GO-Fc/PANI nanocomposite for supercapacitor applications

A novel high-performance nanocomposite based on ferrocene (Fc) functionalized graphene oxide (GO) and polyaniline (PANI) for battery-type supercapacitor applications was successfully synthesized. The GO sheets were functionalized by using 4-ferrocenylbutylamine as a redox compound. Then, the final nanocomposite was obtained by physical treatment of PANI and functionalized GO sheets. The chemical structure, electrochemical behaviors and morphological structure of synthesized compounds were confirmed by Fourier transform infrared spectroscopy (FT-IR), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), galvanostatic charge-discharge measurement (GCD), field emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDX) and X-ray diffraction (XRD) analysis, respectively. The charge storage capacity was calculated from GCD curves. Our calculated results exhibit that the GO-Fc/PANI nanocomposite depicted high mass specific charge retention density of 208 mAh g−1 at current density 2.5 A g−1. These results indicate that the presence of Fc and PANI in the final nanocomposite improved charge transfer property of GO after modification. In addition, the GO-Fc/PANI has shown excellent cycling stability up to 3000 cycles with good retention of 85.54% of the initial charge storage capacity.

Urethane-silica functionalized graphene oxide for enhancing mechanical property and fire safety of waterborne polyurethane composites

Abstract Herein, we first prepared urethane-silica functionalized graphene oxide (FGO) via in-situ method, and then physically incorporated FGO with waterborne polyurethane (WPU) matrix to fabricate composites. It was found that large amounts of urethane-silica components were covalently attached onto the FGO sheets. Moreover, the FGO exhibited spatial distribution in the WPU matrix, leading to excellent dispersibility and compatibility with WPU. Interestingly, the flexible urethane-silica components on the FGO sheets could not only modulate the mechanical properties of WPU/FGOs composites, but also reinforce the carbonaceous block with rigid silicon layer, and thus contributing to the fire safety. The most balanced enhancements in mechanical and flame retardant properties were achieved when 2 wt% FGO was incorporated into the WPU matrix, resulting in a significant increase in tensile strength, elongation at break, and limiting oxygen index (17.1 MPa, 925.0%, and 23.1%, respectively) as compared to the neat WPU. In addition, the WPU/FGOs composites possessed improved water resistance, which maybe potentially favor to the wet rub resistance and self-protective applications. This work provides a potential avenue for designing graphene-based composite and makes it promising application in multifunctional coatings.

Surface-covalent functionalized graphene oxide sheets with hyperbranched polysiloxane and Mn ion for cyanate ester resin: Towards lower curing temperature and higher performance

Achieving lower curing temperature and higher properties has been the significant target for developing heat-resistant thermosetting resins. Herein, a facile covalent approach has been built to fabricate functionalized graphene oxide (HBP@GO/MnF) through grafting hyperbranched polysiloxane (HBP) and hybridizing metal–organic framework with Mn2+ (MnF), which has been proved to have desirable abilities of simultaneously decreasing curing temperature as well as improving toughness and stiffness while maintaining the biggest advantage (low dielectric loss) and high thermal resistance of cyanate ester (BCy) resin. A comparative study demonstrates that the activation from HBP endows HBP@GO/MnF with good dispersion in BCy resin and provides strong interfacial action between HBP@GO/MnF and BCy resin. When the loading of HBP@GO/MnF is as small as 0.5 wt%, the peak temperature of curing reduces to 278 °C from 313 °C of BCy, meanwhile severally about 60%, 98%, 120% and 93% increased flexural strength, flexural modulus, impact strength and fracture toughness are achieved. In addition, all modified BCy resins post-cured at 220 °C/4 h have better mechanical properties and higher heat resistance than pure BCy resin post-cured at 240 °C for 4 h. These outstanding performances prove that HBP@GO/MnF is promising filler for fabricating new resins with higher performances and better curing feature.

Thermo-Responsive Graphene Oxide/Poly(Ethyl Ethylene Phosphate) Nanocomposite via Ring Opening Polymerization.

An efficient strategy for growing thermo-sensitive polymers from the surface of exfoliated graphene oxide (GO) is reported in this article. GO sheets with hydroxyls and epoxy groups on the surface were first prepared by modified Hummer’s method. Epoxy groups on GO sheets can be easily modified through ring-opening reactions, involving nucleophilic attack by tris(hydroxymethyl) aminomethane (TRIS). The resulting GO-TRIS sheets became a more versatile precursor for next ring opening polymerization (ROP) of ethyl ethylene phosphate (EEP), leading to GO-TRIS/poly(ethyl ethylene phosphate) (GO-TRIS-PEEP) nanocomposite. The nanocomposite was characterized by 1H NMR, Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), differential thermal gravity (DTG), transmission electron microscopy (TEM) and atomic force microscopy (AFM). Since hydrophilic PEEP chains make the composite separate into single layers through hydrogen bonding interaction, the dispersity of the functionalized GO sheets in water is significantly improved. Meanwhile, the aqueous dispersion of GO-TRIS-PEEP nanocomposite shows reversible temperature switching self-assembly and disassembly behavior. Such a smart graphene oxide-based hybrid material is promising for applications in the biomedical field.

Luminescence tunability of europium functionalized graphene oxide sheets

Luminescence tunable graphene oxide-europium (GO-Eu) composites were obtained by adopting a fresh composite preparation procedure. Unique GO-Eu precursor compositions maintained in acidic pH range and subjected to ultrasonic treatment were found to exhibit fine tuned emission bands ∼600 nm. FT-IR, XPS and SEM studies evidence the uptake of Eu ions in composite sheets and denote their nature of bonding with various functional groups at multiple sites of GO. Initial interaction of Eu ions with GO involves both adsorption as well as bonding processes while, introduction of acidity and ultrasonic treatments hinder the instant aggregation of composite sheets and facilitate the complexation of Eu ions at most reactive sites of GO. Changes in heterogeneous electronic structure of composite sheets alter the relative intensities of radiative transitions from localized states associated with and cause the observed fine tuning of luminescence from composites. These inferences were assessed by examining the emission features of aged GO-Eu composites exposed to different pH and ultrasonic treatment conditions. Distinctive windows of parameters were proposed to achieve relatively narrow and fine tuned emission bands in the wavelength range of 550–750 nm using fresh and aged GO composite dispersions.

Enhanced hydrophilicity and water-permeating of functionalized graphene-oxide nanopores: Molecular dynamics simulations

In this work, molecular dynamics simulations were employed to study the permeation of ethanol-water mixtures through single-layer graphene oxide (GO) nanopores functionalized with COOH (carboxyl) and COO- (ionized carboxyl) groups. GO-COOH nanopore shows regular behavior with competitive permeation between the two species in the mixture. However, GO-COO- pore exhibits selective permeation of water, suggesting COO- functionalized GO sheets could provide the initial barrier to block ethanol permeation and enhance dehydration separation in GO-based membranes. Our simulation presents the underlying mechanism of the selective water transport is not determined by the pore-size sieving, but has been ascribed as the strong molecular affinity between water and GO-COO- surface. This interfacial interaction can induce the preferential interfacial adsorption and pore occupation for water, simultaneously impede the transport path of ethanol into the nanopore, and consequently give rise to the selective penetration of water in the mixture. The simulation results provide the direct theoretical evidence that ionization of carboxyl groups on GO sheets can be applied to improve the dehydration permeation of alcohol-water mixtures across GO-based separation membranes.

Subsurface Imaging of Functionalized and Polymer-Grafted Graphene Oxide

We investigate the surface and subsurface morphology of stearylamine-modified graphene oxide sheets and polystyrene-grafted functionalized graphene oxide sheets through atomic force microscopy (AFM) operated in multi-set point intermittent contact (MUSIC) mode. This allows a depth-resolved mapping of the nanomechanical properties of the top surface layer of the functionalized graphene oxide sheets. On the surface of stearylamine-functionalized graphene oxide sheets, we can distinguish areas of hydrophilic graphene oxide from hydrophobic areas functionalized with stearylamine. We find that every sheet of graphene oxide is functionalized with stearylamine on both sides of the sheet. The exposure of polystyrene-grafted functionalized graphene oxide to chloroform vapor during the AFM measurement causes a selective swelling and a softening of the polystyrene envelope. The depth-resolved mapping of the tip–sample interaction allows the shape of the folded and wrinkled graphene oxide sheets within the polystyrene envelope to be imaged; furthermore, it allows the thickness of the swollen polystyrene envelope to be measured. This yields the swelling degree, the grafting density, and the average chain conformation of the grafted polystyrene chains, which we find to be in the brush regime. Our work demonstrates a versatile methodology for imaging and characterizing functionalized and polymer-grafted two-dimensional materials on the nanometer scale.

Graphene-polyethylene nanocomposites: Effect of graphene functionalization

The properties of polymer nanocomposites depend strongly on how well nanoparticles are dispersed. However, the hydrophobic nature and low polarity of PE have made effective dispersion of nano-filler difficult without compatibilization. We have found improved dispersion of chemically functionalized graphene oxide (FGO) in PE. The hydroxyl and epoxide groups on graphene oxide (GO) are sites for grafting on functional groups like alkanes. We covalently attach alkyl chains and benzyl moieties to GO. This FGO was solvent blended into three types of polyethylene: high density, linear low density, and oxidized PE matrices. Visual observation of cast films and optical micrographs revealed that FGO was more homogeneously dispersed than unmodified GO. Simple thermal reduction of the FGO sheets dispersed in PE at 210 °C achieved a 10 6 -fold reduction in electrical resistance, much greater than that of other unmodified graphene composites. Moreover the tensile modulus of the low density PE was improved 12-fold and that of the high density PE 3-fold with 5% FGO. • We covalently attach alkyl chains and benzyl moieties to graphene oxide. • This FGO was solvent blended into three types of polyethylene: high density, linear low density, and oxidized PE matrices. • Simple thermal reduction of the FGO sheets dispersed in PE at 210 °C achieved a 10 6 -fold reduction in electrical resistance, much greater than that of other unmodified graphene composites. • Moreover the tensile modulus of the low density PE was improved 12-fold and that of the high density PE 3-fold with 5% FGO.