Graphene Research Articles

Flammability and vibrational study of graphene incorporated epoxy/ramie/glass hybrid nanocomposite

AbstractHybrid polymer composites are vastly used in aerospace, construction, and automotive fields. This study aims to analyze the flammability and vibrational behavior of graphene incorporated epoxy/ramie/glass (ERG) hybrid nanocomposite. The samples were prepared with different weight percentage of graphene (GR) through hand layup method, followed by vacuum bag technique. The samples were analyzed for water intake, porosity, mechanical strength, fractography, vibrational property together with flammability of the material. GR addition depletes water intake and porosity by 11.5% to 5.3% and 6.2% to 2.2%, respectively. It increases hardness and flexural strength up to 25% and 41%, with a reduction in tensile property of the composites. Besides, GR nanocomposites show improved damping properties, owing to stick‐slip mechanism exhibited at epoxy and GR interface. Also, GR addition declines burning rate of ERG at high concentrations since it does not score any grade in flammability test. This work found that the incorporation of GR in ERG composite enhances mechanical properties and decreases water intake. A decrease in the burning rate of the ERG composite could be achieved by incorporating graphene particles, which could be used for structural applications (car door‐panels, ballistic, and aerospace) leading to delay in burning rate of the developed composites when exposed to fire during accidents.

Three‐dimensional graphene/carbon nanotube electromagnetic shielding composite material based on melamine resin foam template

AbstractElectromagnetic shielding materials with good ductility, low density, and high shielding performance have excellent application prospects in communication and electronics, aerospace, and military industry. Lightweight three‐dimensional porous conductive foam composite with high electrical conductivity and electromagnetic shielding efficiency has been widely concerned in recent years. In this study, we prepared a special physically modified carbonized melamine foam (CMF) by synergistic modification with graphene (GNs) and multi‐walled carbon nanotubes (CNTs). The lightweight CMF composite with a Unique 3D pore structure has been constructed to achieve high efficiency in EMI shielding. Taking advantage of the synergistic effect of few‐layer nanosheets and CNTs in tailored microporous structure, 15 wt% GNs‐CNTs/CMF composite demonstrates low density of 0.03 g/cm3 and high electrical conductivity of 34.0 S/m, resulting in a significant EMI shielding effectiveness as 3840 dB⋅cm2/g. The microporous architecture contributes to multiple reflection losses of electromagnetic waves by introducing multiple interfaces and also improves the construction of conductive paths to deliver outstanding shielding performance. This work illustrates reference significance for the potential application of lightweight EMI shielding materials with target functions.

Uranium extraction by a graphene-based asymmetric electrode configuration through combined complexation, electro-adsorption, and photocatalytic reduction

Recently, capacitive deionization has become a promising approach for uranium extraction owing to its energy-efficiency and environmental benign. However, theadsorbedchargeduranium(VI)(U(VI))wouldrepulsetheincomingU(VI)ions,andmightre-enterintosolution,vastlyimpedingtheimprovementofelectro-adsorptionperformance. Reducing the adsorbed U(VI) ions into U(IV) precipitation is an ideal way to address above issues. Here, a coupling approach of photocatalytic reduction and electro-adsorption (PEA) was proposed. An asymmetric electrode configuration, composed of phosphate functionalized graphene (GP) cathode and graphene/TiO2 nanocomposite (GT) anode was rationally designed, and originally proved its enhanced U(VI) extraction via the PEA method. The asymmetric electrode device enables the fast transport of photo-electron and the rapidly directed migration of U(VI) ion to the GP cathode. More importantly, it combines three synthetic mechanisms of complexation, electro-adsorption, and photocatalytic reduction to extract U(VI) ions. As a consequence, the as-designed PEA method shows a higher removal rate of 91.3% in comparison with conventional photocatalytic reduction (PA) and electro-adsorption (EA) methods. Meanwhile, its kinetics rate is 225% and 50% faster than PA and EA methods. Furthermore, an enhanced reduction efficiency of U(VI) to U(IV), good selectivity as well as reusability for PEA method were also obtained. The results provide a potential approach to combine multiple mechanisms for efficient U(VI) extraction from aqueous solution by purposeful design of asymmetric electrodes.

Bio-Electroanalysis Performance of Heme Redox-Center for π-π Interaction Bonding of a Methylene Blue-Graphene Modified Electrode.

Hemeprotein detection has motivated extensive research on the direct reaction of a heme molecule and a redox dye. The present study used methylene blue as both donor and acceptor for a redox reaction. First, the solid phases of methylene blue (MB) and graphene (GP) formed a π-π interaction bond at the aromatic rings. The conductivity of GP was better than that of carbon in a carbon electrode (CE). Then, the working CE was modified using strong adsorption of MB/GP on the electrode surface. The surface of the electrode was investigated using a modified and an unmodified electrode. The electrode's properties were studied using voltammograms of redox couple K3[Fe(CN)6]3-/4-. Its reaction was used to find the active area of the modified electrode, which was 1.76 times bigger than that of the unmodified electrode. The surface coverage values of the modified and unmodified electrodes were 8.17 × 10-6 and 1.53 × 10-5 mol/cm2, respectively. This research also studied the application of hemeprotein detection. Hemoglobin (Hb), myoglobin (Mb), and cytochrome c (Cyt. C) were studied by the reaction of Fe (III/II) at the heme-redox center. The electrocatalytic reaction between MB/GP and hemeproteins produced an anodic peak at 0.35 V for Hb, Mb, and Cyt. C. This nanohybrid film enhanced electron transfer between protein molecules and the modified carbon electrode. The amperometric measurements show that the limit of detection was 0.2 µM, 0.3 µM, and 0.1 µM for Hb, Mb, and Cyt. C, respectively. The measurement spanned a linear range of 0.2 µM to 5 µM, 0.3 µM to 5 µM, and 0.1 µM to 0.7 µM for Hb, Mb, and Cyt. C, respectively. Hb showed the lowest sensitivity compared with Mb and Cyt. C due to the role of steric hindrance in the hemeprotein specificity structure. This study offers a simple and efficient fabrication platform for electrochemical sensors for hemeproteins. When compared to other complex immobilization processes, the fabrication method for this sensor has many benefits, including no need for special chemicals and easy preparation and electrode modification-both of which are crucial for the development of electrochemical sensing devices.

An intelligent biosensing procedure based on three-way calibrations and generation of second-order hydrodynamic square wave voltammetric data for detection of DNA damage and simultaneous biosensing of three polycyclic aromatic hydrocarbons

In this work, we have generated second-order hydrodynamic square wave voltammetric (HSWV) data and analyzed them by multivariate curve resolution-alternating least squares (MCR-ALS) for simultaneous determination of the rates of deoxyribonucleic acid (DNA) damages induced by benzo(a)pyrene (BP), dibenzo(a,e)pyrene (DBP) and indeno(1,2,3-cd)pyrene (IP). A thick-film boron doped diamond electrode (TFBDDE) was used as the platform of the biosensor, and it was modified by graphene (GR), cobalt nanoparticles (Co NPs), horseradish peroxidase (HRP), and DNA. The double stranded DNA and HRP were immobilized onto the surface of Co NPs/GR/TFBDDE by the use of nafion. The HRP in the presence of hydrogen peroxide (H2O2) can mimic enzymatic effects of cytochrome P450 (CP450) to metabolize BP, DBP, and IP to cause DNA damage. The HSWV responses of DNA-HRP/Co NPs/GR/TFBDDE to BP, DBP, and IP were individually calibrated to obtain individual rates of DNA damages induced by BP, DBP, and IP. Then, the second-order HSWV data were generated and modeled by parallel factor analysis2 (PARAFAC2), MCR-ALS, multi-way partial least squares/residual bilinearization (N-PLS/RBL), and unfolded partial least squares/residual bilinearization (U-PLS/RBL) to choose the best second-order calibration model for simultaneous determination of rates of DNA damages induced by BP, DBP and IP. The biosensor assisted by MCR-ALS showed the best performance among the mentioned algorithms, and it was expanded to simultaneous determination of BP, DBP and IP whose performance was compared by the biosensor assisted by amperometric data as well. Interestingly, the biosensor assisted by amperometric data and RBF-PLS showed a better performance in simultaneous determination of BP, DBP and IP. The biosensor assisted by amperometric data and RBF-PLS was successful in simultaneous determination of BP, DBP and IP in wastewater samples as real matrices. Protective effects of the Myrtus communis L extract against DNA damage was also investigated, and our records confirmed antioxidant effects of Myrtus communis L extract against DNA damage.

Effects of Graphene on the Transport of Quinolones in Porous Media

The effect of graphene (GN) on the transport of CIP and NOR in porous media is investigated by a combination of batch experiments, column experiments and mathematical models. The results obtained by batch experiments show that GN has great adsorption capacity to two antibiotic contaminants, and the maximum adsorption amounts based on the Langmuir model calculation are 270.67 mg/g and 178.36 mg/g, respectively. The column experiments suggest the mobility of CIP and NOR decreases with the mass fraction of GN packed in porous media, and the mass recovery rates of CIP and NOR increase with flow velocity. As the concentration of Na+ increases, the mobility of CIP and NOR is enhanced. However, Ca2+ has a significant enhancement effect on the mobility of CIP and NOR. Moreover, the transport processes of CIP and NOR in the column are predicted by a BDST mathematical model, and the calculated results are in good agreement with the experimental results. The relationships between kinetic parameters related to QNs’ mobility and GN content, flow velocity and ionic strength are obtained by a regression analysis, which can be used to predict the mobility of CIP and NOR in porous media.

From 2D to 3D: the story of graphene in objects

From 2D to 3D: the story of graphene in objects

The Cytotoxicity of Carbon Nanotubes and Hydroxyapatite, and Graphene and Hydroxyapatite Nanocomposites against Breast Cancer Cells.

Cancer is a current dreadful disease and the leading cause of death. Next to cardiovascular diseases, cancer is the most severe threat to human life and health. Breast cancer is the most common invasive cancer diagnosed in women. Each year about 2.3 million women are diagnosed with breast cancer. In consideration of the severity of breast cancer, herein we designed the biocompatible nanomaterials, CNTs-HAP and GR-HAP, through grafting of hydroxyapatite (HAP) to carbon nanotubes (CNTs) and graphene (GR) nanosheets. CNTs-HAP and GR-HAP have been tested for their cytotoxicity, growth and motility inhibitory effects, and their effects on the mesenchymal markers. All these demonstrated significant dose-dependent and time-dependent in vitro cytotoxicity against SUM-159 and MCF-7 breast cancer cell lines. The cell viability assay showed that the CNTs-HAP was more effective over SUM-159 cells than MCF-7 cells. It found that the increase in the concentration of GR-HAP has inhibited the clonogenic ability of breast cancer cells. The GR-HAP exhibited a substantial inhibitory effect on the cell motility of SUM-159 cell lines. It was investigated that the expression of vimentin (mesenchymal marker) was majorly reduced in SUM-159 cells by GR-HAP.

Interlaced CoOx Nanosheets Composited with Reduced Graphene Oxide and Carbonized Bacterial Cellulose as Anode Materials for Lithium‐ion Batteries

AbstractConstructing peculiar carbon‐based networks built from hybrid structures has been considered as an effective approach to establish a superior scaffold for immobilization of nanoparticles. Herein, we demonstrate a facile and green approach to prepare cobalt oxides (CoOx)‐based anode, which is realized by rationally exploiting unique properties of carbonized bacterial cellulose (CBC) and graphene (GN). The unique configuration of GN/CoOx/CBC composite fully enables utilization of the synergistic effects from both three‐dimensional nanofibrous network and two‐dimensional “flexible confinement” function. Benefiting from their intriguing structural features, the synthesized composite is directly used as electrode for lithium‐ion batteries (LIBs), and achieves superior flexibility and reliability, enhanced energy/power density and outstanding cycling stability.

Superhydrophobic and Conductive Foams with Antifouling and Oil–Water Separation Properties

Hybrid organic-inorganic materials are attracting enormous interest in materials science due to the combination of multiple advantageous properties of both organic and inorganic components. Taking advantage of a simple, scalable, solvent-free hard-sacrificial method, we report the successful fabrication of three-dimensional hybrid porous foams by integrating two types of fillers into a poly(dimethylsiloxane) (PDMS) framework. These fillers consist of hydrophobic electrically conductive graphene (GR) nanoplatelets and hydrophobic bactericidal copper (Cu) microparticles. The fillers were utilized to create the hierarchical rough structure with low-surface-energy properties on the PDMS foam surfaces, leading to remarkable superhydrophobicity/superoleophilicity with contact angles of 158 and 0° for water and oil, respectively. The three-dimensional interconnected porous foam structures facilitated high oil adsorption capacity and excellent reusability as well as highly efficient oil/organic solvent-water separation in turbulent, corrosive, and saline environments. Moreover, the introduction of the fillers led to a significant improvement in the electrical conductivity and biofouling resistance (vs whole blood, fibrinogen, platelet cells, and Escherichia coli) of the foams. We envision that the developed composite strategy will pave a facile, scalable, and effective way for fabricating novel multifunctional hybrid materials with ideal properties that may find potential use in a broad range of biomedical, energy, and environmental applications.

Fluorinated graphene films for Ultra-High sensitivity of Surface-Enhanced Raman scattering

It is of great importance to design large-area and high-quality graphene and its derivatives for the application in surface-enhanced Raman scattering (SERS) with high sensitivity and good stability. The efficiently preparation and accurately regulation of these structures remain great challenges. Herein, fluorinated graphene (fGE) for high-performance SERS is developed by a facile fluorination on a sub-centimeter graphene. With precisely controlling the nucleation density of the graphene growth by NH3-plasma assistance, this large-area graphene (GE) was obtained on Cu foil. Then GE reacted with the derived F atoms from fluorocarbon in a tube furnace at 600 °C. SERS results demonstrate that the fGE films exhibit extraordinary Rhodamine 6G (R6G) molecular SERS sensitivity limit as low as 10−9 mol/L (M) by tuning the F/C ratio of the fGE in range of 0.024–0.234. The Raman intensity of probe molecules adsorbed on as-prepared fGE revealed a slight decrease to 98.2 % for R6G on fGE as long as 50 days, demonstrating good stability for fluorinated-graphene-enhanced Raman scattering (FGERS). Furthermore, theoretical calculations also indicate that the energy of a specific laser matches the gap between the lowest unoccupied molecular orbital (LUMO) of as-designed probe molecule (Rhodamine 6G, Methylene Blue) and Fermi level of fGE, which favors SERS chemical enhancement. This large-scale preparation of FGERS substrates with outstanding sensitivity opens a light way for potential SERS substances.

A new teamwork of PEDOT:PSS and zinc peroxide decorated nitrogen doped graphene with high anisotropic thermoelectric functions

Poly(3,4-ethylenedioxythiophene):Poly (styrene sulfonate) (PEDOT:PSS) as an intrinsic conductive polymer has captured much curiosity since the discovery of its high thermoelectric (TE) functions. So, the progress on the enhancement of TE functions of PEDOT:PSS and its composite is still having much attention thanks to its unique merits such as flexibility, low toxicity, as well as its promising TE functions. Thus, in this work, we offer a new teamwork of PEDOT:PSS and Zinc peroxide adorned Nitrogen doped Graphene (PEDOT:PSS/ZnO2NG) to record high TE performance. This teamwork plays in harmony to record a high TE functions as; the doping of graphene (GN) with Nitrogen helps in reducing the thermal conductivity (κ) via the creation of interfaces and voids which lead to scattering the phonons. The decoration of ZnO2 on NG surface helps in increasing the electrical conductivity (σ) by the increase in carrier mobility and declining the κby reducing the stacking nature of NG layers. The anisotropic (through plane ⊥ and in plane //) TE functions have been recorded at 300 K. The system shows that the highest TE functions are achieved at ZnO2NG = 30 wt%. At this concentration, σ//∼1600.45 ± 62 S/cm and σ⊥∼1203.98 ± 56 S/cm have been achieved, thanks to the strong interactions among ZnO2NG and PEDOT:PSS; and the increase in carrier mobility. κ//∼0.47 ± 0.01 W/mK and κ⊥∼0.35 ± 0.01 W/mK have been achieved. The S//∼25.94 ± 0.6 μV/K and S⊥∼23.2 ± 0.59 μV/K have been achieved thanks to the decrease in the carrier concentration. The power factors (PF//∼107.69 ± 3 μW/mK2 and PF⊥∼64.80 ± 4 μW/mK2) have been achieved owing to the energy filtering effects at the interfaces. Accordingly, the obtained figure of merits (zT// ∼0.068 ± 0.001 and zT⊥∼0.055 ± 0.002) have been achieved which can compete the largest zT values when compared with similar systems. Finally, the obtained PEDOT:PSS/ZnO2NG system shows a promising TE functions which elects it to be functionalized in various technologies such as electronic, temperature sensing and wearable devices.

Molecular mechanisms of integrin αvβ8 activation regulated by graphene, boron nitride and black phosphorus nanosheets

Integrin αvβ8 is a heterodimeric transmembrane protein on macrophages. Nanosheets can activate the integrin and elicit immune responses, exhibiting adverse immunotoxicity. Understanding the mechanism of integrin activation regulated by nanosheets is crucial for safe and effective use of nanosheets in biomedical applications. Herein, we performed all-atom molecular dynamics simulations to clarify the interactions between integrin αvβ8 in the cell membrane and three types of nanosheets, graphene (GRA), hexagonal boron nitride (BN), and black phosphorus (BP). We observed that BP could adsorb the intracellular end of αv monomer and thus break the inner membrane clasp, an important hydrophobic cluster for maintaining the inactive state of integrin. The association between αv and β8 subunit is weakened, promoting the integrin activation. By contrast, GRA and BN exert little influence on the association state of the integrin. Interestingly, the puckered structure of BP affects the integrin activation, where BP with the armchair direction perpendicular to the membrane plane cannot unpack the integrin. Moreover, the perturbation effect of nanosheets on the membrane was also evaluated. BP shows a milder effect on membrane structures and lipid properties than GRA and BN. This work unravels the molecular basis on the activation of integrin mediated by three nanosheets, and suggests the toxicity and therapeutic effect of well-established nanomaterials in the immune system.

Energy-efficient electrochemical degradation of ciprofloxacin by a Ti-foam/PbO2-GN composite electrode: Electrode characteristics, parameter optimization, and reaction mechanism

Reducing energy comsuption is crucial to commercialize electrochemical oxidation technologies. In this study, a novel PbO2 composite electrode (Ti-foam/PbO2-GN) was successfully fabricated based on a porous titanium (Ti) foam substrate and a β-PbO2 active layer embedded with multiple graphene (GN) interlayers, and applied as an anode for energy-efficient pulse electrochemical oxidation of ciprofloxacin (CIP). In contrast to PbO2 and Ti-foam/PbO2 electrodes, the Ti-foam/PbO2-GN electrode surface exhibited a more compact structure, smaller crystal grain size, and greater electrochemical active surface area. CIP removal of 89.7% was obtained with a low energy consumption (EE/O) of 6.17 kWh m−3 under pulse electrolysis conditions with a current density of 25.00 mA cm−2, pulse frequency of 5000 Hz, and pulse duty cycle of 50.0%. Up to 70.7% of the energy was saved in the pulse current mode compared to the direct current mode. Narrowing the electrode spacing to 2 cm facilitated the mass transfer process and enhanced oxidation efficiency. According to the intermediates identified, the pulse electrolysis of CIP primarily involved hydroxylation of the quinolone ring, breaking of the piperazine ring, defluorination, and decarboxylation processes, and a possible degradation mechanism of CIP was proposed. The continuous oxidation performance of CIP and the relatively low leaching of Pb2+ suggested that the Ti-foam/PbO2-GN electrode exhibited excellent stability, repeatability, and safety. The degradation results of CIP in real water also exhibits the great potential of environmental application. As a result, pulse electrochemical oxidation using a Ti-foam/PbO2-GN electrode has proven to be an energy-efficient and promising alternative for antibiotic wastewater treatment.

Adsorption of Favipiravir on pristine graphene nanosheets as a drug delivery system: a DFT study.

The efficiency of pristine graphene (GN) in the delivery process of the Favipiravir (FPV) anti-COVID-19 drug was herein revealed within the FPV⋯GN complexes in perpendicular and parallel configurations in terms of the density functional theory (DFT) method. Adsorption energy findings unveiled that the parallel configuration of FPV⋯GN complexes showed higher desirability than the perpendicular one, giving adsorption energy up to -15.95 kcal mol-1. This favorability could be interpreted as a consequence of the contribution of π-π stacking to the overall strength of the adsorption process in the parallel configuration. Frontier molecular orbitals (FMO) findings demonstrated the ability of the GN nanosheet to adsorb the FPV drug by the alteration in the EHOMO, ELUMO, and Egap values before and after the adsorption process. Based on Bader charge results, the FPV drug and GN sheet exhibited electron-donating and -accepting characters, respectively, which was confirmed by the negative sign of the computed charge transfer (Qt) values. The FPV(R)⋯T@GN complex showed the most desirable Qt value of -0.0377e, which was in synoptic with the adsorption energy pattern. Electronic properties of GN were also altered after the adsorption of the FPV drug in both configurations, with more observable changes in the parallel one. Interestingly, the Dirac point of the GN sheet coincided with the Fermi level after the adsorption process, indicating that the adsorption process unaffected the presence of the Dirac point. The occurrence of the adsorption process was also noticed by the existence of new bands and peaks in the band structure and DOS plots, respectively. Short recovery time rendered the GN nanosheet an efficient FPV drug delivery system. The obtained findings provide new insight into the biomedical applications of the GN sheet as a promising drug delivery system.

Graphene doping to enhance the mechanical energy conversion performances of GR/KNN/P(VDF-TrFE) flexible piezoelectric sensors.

Flexible piezoelectric composite, combining high piezoelectricity of filler and flexibility of polymer, provides a new research idea for developing flexible piezoelectric sensors (FPSs) with high piezoelectric output performance. FPSs based on GR/KNN/P(VDF-TrFE) three-phase composites are fabricated via doping a mass fraction of 15 wt% potassium sodium niobate (KNN) ceramic powder and various contents of graphene (GR) nanosheets into a P(VDF-TrFE) matrix. We find that an appropriate amount of GR is responsible for the enhanced crystallinity and β-phase of P(VDF-TrFE). When the GR content is 0.15 wt%, the three-phase composite film exhibits a dielectric constant (εr) of 20.9 and a quasi-static piezoelectric constant (d33) of -28.4 pC N-1. Under three different test scenarios of a ball drop experiment, a surface of the mouse wheel, and an action of 2.5 MPa external stress, this GR/KNN/P(VDF-TrFE)-based FPS shows high piezoelectric output voltages of 7.4 V, ∼2.0 V, and 15.4 V, respectively. Moreover, the FPS retains its performance even after an extended period of cantilever vibration cycles (2200). Thus, the conductive filler GR is responsible for promoting the energy conversion performance of the piezoelectric polymer, which also provides an application candidate of this GR/KNN/P(VDF-TrFE) film in FPSs.

A graphene/h-BN MEMS varactor for sub-THz and THz applications.

Recent development of terahertz systems has created the need for new elements operating in this frequency band, i.e., fast tunable devices such as varactors. Here, we present the process flow and characterization of a novel electronic variable capacitor device that is made with the use of 2D metamaterials such as graphene (GR) or hexagonal boron nitride (h-BN). Comb-like structures are etched into a silicon/silicon nitride substrate and a metal electrode is deposited at the bottom. Next, a PMMA/GR/h-BN layer is placed on top of the sample. As voltage is applied between GR and metal, the PMMA/GR/h-BN layer bends towards the bottom electrode thus decreasing the distance between electrodes and changing the capacitance. The high tunability and complementary metal oxide semiconductor (CMOS)-compatible process flow of the platform for our device and its millimeter size make it promising for applications in future electronics and terahertz technologies. The goal of our research is to integrate our device with dielectric rod waveguides, thus making THz phase shifters.

RECENT ADVANCES IN MODELING AND EXPERIMENTAL PREDICTION OF PROPERTIES OF GRAPHENE REINFORCED NATURAL RUBBER COMPOSITES: A REVIEW (PART 1)

This review provides an overview of research done in the area of rubber-based nanocomposite materials. The main focus of the article is reviewing the characteristics of graphene (GE) as a reinforcing material. The review covers the recent development in dispersion techniques for the inclusion of GE in the rubber matrix. An alternative, or pre-experimental procedure of molecular dynamics simulation to reduce the cost and wastage as well as to open the vast field of study in this area, has been proposed. The effect of volume fraction, weight percentage, and functionalization of filler on the properties of rubber composites has also been discussed. The elastic modulus, as well as the thermal conductivity of GE/NR composites, were found to be superior in comparison to the graphene oxide (GO) and rGO reinforced natural rubber (NR) composites. The tensile strength of GE/NR composites increased significantly at lower parts per hundred rubber (phr) values (0.3-1.5) whereas the properties did not increase significantly at higher phr values of GE. This review article also encourages additional research in the area of interest, intending to assist researchers to conduct the study in this field, leading to the development and progress in the mechanical, thermal, and other properties of rubber nanocomposites and their applications.

Bimetallic FeNi Alloy Nanoparticles Grown on Graphene for Efficient Removal of Congo Red From Aqueous Solution

AbstractNano zero‐valent iron (nZVI) is an effective material for dye wastewater treatment, but excessive agglomeration and oxidation greatly limit its application. Herein, graphene (GR) supported FeNi bimetallic nanoparticles (FeNi@GR) are prepared by alloying and carrier supported dispersion for efficient removal of azo dyes from water. Not only can it effectively solve the problem of excessive agglomeration and oxidation of nZVI, but also the synergistic effect of bimetallic coordination formation and the excellent electron transfer ability of graphene are beneficial to enhance the reactivity of FeNi@GR. The optimal FeNi@GR is prepared by adjusting the content of GR and the removal of Congo red (CR) by FeNi@GR‐10% reached 625 mg g−1 within 150 min at pH = 7.0. Higher temperature and lower pH favor the removal of CR azo dye. The action mechanisms of FeNi@GR presumably involve the transfer of active hydrogen atoms and the transfer of electrons generated by Fe0 and Ni0. Besides, the saturation magnetization (Ms) of FeNi@GR is 68.15 emu g−1, which has excellent magnetic response performance. This work not only provides a simple and efficient method to stabilize nZVI, but also reveals that using FeNi@GR is a promising approach for the remediation of water pollution.

The Study of Enteromorpha-Based Reinforcing-Type Flame Retardant on Flame Retardancy and Smoke Suppression of EPDM

Enteromorpha, as a waste from marine pollution, brings great pressure to environmental governance every year, especially for China. Under the premise of a shortage of industrial materials, taking appropriate measures can turn waste into wealth, which will benefit us a lot. In this work, a bio-based reinforcing-type flame retardant based on Enteromorpha is designed. The designed Enteromorpha-based flame retardant system (AEG) mainly focuses on the reinforcing and flame retardant effects on ethylene-propylene-diene tripolymer (EPDM). For the AEG system, ammonium polyphosphate (APP) serves as both the acid source and the gas source; the simple hybrid material (GN) produced by loading graphene (GE) and Enteromorpha (EN) using tannic acid (TA) as a regulator serves as an acid source and a carbonizing source. The results show that when 40 phr AEG is added, the LOI of EPDM/AEG40 reaches 32.5% and the UL-94 reaches the V-0 level. The PHRR and THR values of EPDM/AEG40 are 325.9 kW/m2 and 117.6 MJ/m2, respectively, with decrements of 67.3% and 29.7%, respectively, compared with the results of neat EPDM composite. Especially, the TSP and TSR values of EPDM/AEG40 are reduced from 15.2 m2 of neat EPDM to 9.9 m2 with a decrement of 34.9% and reduced from 1715.2 m2/m2 of neat EPDM to 1124.5 m2/m2 with a decrement of 34.4%, indicating that AEG is effective in flame retardancy and smoke suppression. Meanwhile, the tensile strength and tear strength of EPDM/AEG composites are much higher than neat EPDM, therefore, with the future development of innovate reinforcing-type flame-retardant Enteromorpha, the application of Enteromorpha in the polymer flame-retardant field will surely usher in bright development.