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This work includes preparing and studying a transparency polymeric coating that has good tribological and mechanical properties. Coating enhanced with nanoparticles can absorb UV radiation while keeping transparency. Also, coating leads to lowering the friction coefficient that improves the coating's wear resistance performance for mobile and computer screen applications, also it leads to increasing the life span of car lamp covers and glass, plastic windows and coating of solar cells. The nanocomposite coating consists of Graphene oxide (GO), Graphene oxide modified (MGO). Composite coating samples with GO and MGO nanoparticles at various weight percentages (0, 0.25, 0.5, and 1 wt%) were created by employing a solution mixing process. Scanning electron microscopy (SEM) was used to evaluate the distribution of nano and fracture failure. Hardness, DSC, wear and scratch tests were done. Additionally, the relationship between tribological and mechanical behavior was studied, as well as the mechanical properties of PMMA nanocomposites coating with the nanoparticle addition. The results showed that adding GO, MGO nanoparticles enhanced the PMMA's tribological performance. It was discovered that PMMA nanocomposites coating had a lower wear and friction coefficient than pure PMMA coating. According to the microstructure data, the ultrasonic treatment significantly contributed to the nanoparticles' good dispersion and decreased agglomeration. The results of mechanical qualities, such as hardness, demonstrated a discernible improvement.. [ABSTRACT FROM AUTHOR]

Waterborne epoxy (WEP) coatings with enhanced corrosion resistance were prepared using graphene oxide (GO) that was obtained from kish graphite, and amino-functionalized graphene oxide (AGO) was modified by 2-aminomalonamide. The structural characteristics of the GO and AGO were analyzed using X-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). And the anti-corrosive performance of waterborne epoxy-cased composite coatings with different addition amounts of AGO was investigated using electrochemical measurements, pull-off adhesion tests, and salt spray tests. The results indicate that AGO15/WEP with 0.15 wt.% of AGO has the best anti-corrosive performance, and the lowest frequency impedance modulus increased from 1.03 × 108 to 1.63 × 1010 ohm·cm−2 compared to that of WEP. Furthermore, AGO15/WEP also demonstrates the minimal corrosion products or bubbles in the salt spray test for 200 h, affirming its exceptional long-term corrosion protection capability. [ABSTRACT FROM AUTHOR]

Waterborne epoxy (WEP) coatings with enhanced corrosion resistance were prepared using graphene oxide (GO) that was obtained from kish graphite, and amino-functionalized graphene oxide (AGO) was modified by 2-aminomalonamide. The structural characteristics of the GO and AGO were analyzed using X-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). And the anti-corrosive performance of waterborne epoxy-cased composite coatings with different addition amounts of AGO was investigated using electrochemical measurements, pull-off adhesion tests, and salt spray tests. The results indicate that AGO15/WEP with 0.15 wt.% of AGO has the best anti-corrosive performance, and the lowest frequency impedance modulus increased from 1.03 × 108 to 1.63 × 1010 ohm·cm−2 compared to that of WEP. Furthermore, AGO15/WEP also demonstrates the minimal corrosion products or bubbles in the salt spray test for 200 h, affirming its exceptional long-term corrosion protection capability.

Copyright of Plastics Science & Technology / Suliao Ke-Ji is the property of Plastics Science & Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The coating with amphiphilic honeycomb surface containing modified graphene oxide was constructed by a three-step method for improved antifouling properties. Graphene oxide is modified with potassium hydroxide and γ-aminopropyltriethoxysilane, and then the product is dispersed in water and ethanol. Isophorone diisocyanate, polyethylene glycol, and γ-aminopropyltriethoxysilane are used to construct an amphiphilic prepolymer. The honeycomb surface is constructed during the evaporation of water and ethanol and the mixing of the modified graphene oxide and prepolymer. The amphiphilic honeycomb surface gives the coating fouling resistance and fouling release, while the modified graphene oxide gives the coating fouling degradation. The coating's amphiphilicity, microstructure, and antifouling properties are characterized by the contact angle, confocal laser scanning microscope, scanning electron microscopy, benthic diatom, and bacterial adhesion. The results show that the coatings form an amphiphilic surface with a honeycomb microstructure and exhibit good antifouling properties. The water, diiodomethane, and 1-bromonaphthalene contact angle can be less than 20°. The size and depth of the honeycomb microstructure are about 600 nm and 100–200 nm. Compared with traditional polyurethane and waterborne silicone coatings, the resistance to benthic diatom and bacteria is increased by at least 28 and 400 times, respectively. [ABSTRACT FROM AUTHOR]

Graphene oxide (GO) as a new nano-enhancer in cement-based materials has gained wide attention. However, GO is easy to aggregate in alkaline cement mortar with poor dispersibility. This hinders its application in practical infrastructure construction. In this work, GO-M18 polycarboxylate compound superplasticizer (GM) were obtained by compounding the M18 polycarboxylate superplasticizer with GO solution at different mass ratios. The dispersion of GM in alkaline solution was systematically studied. The phases and functional groups of GM were characterized by XRD and FTIR. The effects of GM on the cement mortar hydration and the formation of microstructure were investigated by measuring the heat of hydration, MIP, TG/DSC, and SEM. The results show that the long-chain structure of the M18 polycarboxylate superplasticizer can increase the interlayer spacing of GO and weaken the force between GO sheets. The modified GO can be uniformly dispersed in the cement slurry. GM can accelerate the early hydration process of cement, which can increase the content of Ca(OH)2 and decrease the grain size. It can optimize the pore size distribution of cement-based materials, increase the density of harmless and less harmful pores, thereby improving mechanical properties. Such methods can transform traditional cement-based materials into stronger, more durable composites, which prolong the life of cementbased materials and reduce the amount of cement used for later maintenance. This provides an idea for achieving sustainability goals in civil engineering. [ABSTRACT FROM AUTHOR]

A waterborne epoxy coating with superior corrosion resistance was developed by using a novel amino-functionalized graphene oxide (GO) that was modified by 2,5-diaminobenzenesulfonic acid. A battery of characterization methods, such as Fourier transform infrared spectroscopy (FT-IR), Raman spectra, X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM), was used to prove that DGO was successfully prepared by grafting the amino of 2,5-diaminobenzenesulfonic on GO. The results indicated that the surface of DGO became rougher than GO, but a complete sheet structure was still maintained after modification; the optimal modified GO could be achieved when the mass ratio of 2,5-diaminobenzenesulfonic acid and GO was 5:1. The electrochemical impedance spectroscopy (EIS) tests indicated that the impedance at 0.01 Hz of a coating with 0.2 wt.% DGO still remained at a relatively high value after immersion for 48 h in 3.5 wt.% NaCl, which was about one order higher than a pure waterborne epoxy resin coating, and the corrosion current density decreased from 3.76 × 10−11 A/cm2 to 3.62 × 10−12 A/cm2. The dry adhesion and wet adhesion increased to 1.90 and 1.22 MPa, respectively, and the adhesion loss decreased from 53% to 36%. These interesting features could make waterborne epoxy coatings a promising anticorrosion coating for metal in long-term protection. [ABSTRACT FROM AUTHOR]

In regard to the nonfatal harm self‐healing of natural species, microcapsule‐based polymeric materials for self‐healing have been considered to be highly desirable in light of their ability to heal cracks in significant volumes, leaving the original chemical structures of polymers unchanged. Accordingly, this study sought to design a one‐component photo‐responsive self‐healing polymer composite based on Bisphenol A epoxy acrylate resin @graphene oxide microcapsules (BAEA@GOMCs) that are capable of photo‐absorption in order to reduce difficulties of processing and inhomogeneous distributions of the two components. Embedding of BAEA@GOMCs were carried out in waterborne epoxy matrix, and self‐healing composite coatings were generated onto surfaces of hot‐dip steel via galvanization. Upon incurring mechanical damage, solidification of the agents of photo‐responsive healing and the flowing the cracks were achieved as the agents were exposed to light to achieve self‐healing. In addition, the solidification within the unbroken microcapsules was maintained, and there were continuous no reactions. Given the simplicity of the proposed preparation, incorporating light‐absorbing particles into the microcapsule shell can further broaden the application range of the aforementioned common materials. [ABSTRACT FROM AUTHOR]

In this work, graphene oxide (GO) and vinyl modified GO (V‐GO)‐based nanocomposite hydrogels with improved mechanical property and self‐healing ability have been synthesized and characterized. GO first was synthesized by modified Hummer's method using graphite powder and then functionalized with vinyl groups by using (3‐mercaptopropyl) trimethoxysilane (MPTS) via silanization method. The GO and V‐GO nanoparticles were characterized by FT‐IR, UV–vis spectroscopy, SEM, and dynamic light scattering technique (DLS). Hydrogels were obtained by in‐situ free‐radical polymerizations of acrylamide (AAm) and [3‐(methacryloylamino)propyl] trimethylammonium chloride (MAPTAC) monomers in the presence of GO and V‐GO nanoparticles. The effects of the amount of GO and V‐GO on the gelation profile and viscoelastic characteristics of the hydrogels were studied. The pH‐responsive action, swelling behavior, and swelling kinetics of the hydrogels with various GO and V‐GO contents were also evaluated. The mechanical performance of nanocomposite cationic hydrogels prepared with GO and V‐GO nanosheets was compared to the neat AAm‐MAPTAC hydrogels. The self‐healing ability of the hydrogels were elucidated as a function of the amount of GO and V‐GO nanosheets bound to the polymer network by physical interactions and chemical cross‐links, respectively. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Henan University of Science & Technology, Natural Science is the property of Editorial Office of Journal of Henan University of Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Graphene oxide, as a new two-dimensional material, has a large specific surface area, high thermal stability, excellent mechanical stability and exhibits hydrophilic properties. By combining the carboxyl groups on the surface of graphene oxide with hydrophilic groups, surfactant-like polymers can be obtained. In this paper, based on the molecular dynamics method combined with the first nature principle, we first determine the magnitude of the binding energy of three different coupling agents—alkylamines, silane coupling agents, and haloalkanes—and analytically obtain the characteristics of the soft reaction. The high stability of alkylamines and graphene oxide modified by cetylamine, oil, and water models was also established. Then, three different chain lengths of simulated oil, modified graphene oxide–water solution, and oil-modified graphene oxide–water systems were established, and finally, the self-aggregation phenomenon and molecular morphology changes in modified graphene oxide at the oil–water interface were observed by an all-atom molecular dynamics model. The density profile, interfacial formation energy, diffusion coefficient and oil–water interfacial tension of modified graphene oxide molecules (NGOs) at three different temperatures of 300 K, 330 K, and 360 K were analyzed, as well as the relationship between the reduced interfacial tension and enhanced oil recovery (EOR). [ABSTRACT FROM AUTHOR]

Silicon (Si)-based materials show attractive potentials as the anode for lithium-ion batteries (LIBs) due to their high theoretical specific capacity. For the conventional silicon/reduced graphene oxide (Si/rGO) composites, the electrical conductivity, C/O ratio, and defect structure of reduced graphene oxide (rGO) significantly impact their electrochemical properties. Herein, we use three methods to prepare graphite oxide (GO) to adjust the percentage of functional groups, which further enhance the physicochemical properties of rGO and thus improve the electrochemical properties of Si/rGO. The GOs were synthesized through Hummers method (labeled as GO-1), Hummers method with H 2 O modulation (labeled as GO-2), and Hummers method with H 2 O and H 3 BO 3 modulation (labeled as GO-3). Due the H 2 O promotes the production of hydroxyl and epoxy groups, and H 3 BO 3 forms complexes with hydroxyl groups,the ratio of hydroxyl and epoxy groups in GO-1 to GO-3 is increased. After reduction process, the reduced rGO-3 exhibits a high C/O ratio, large structural defects, and excellent electrical conductivity. Because of the excellent properties of rGO-3, as an electrode material, Si/rGO-3 exhibits excellent electrochemical performance, with the highest reversible capacity of about 780.8 mAh/g after 150 cycles at 1 A/g and a good rate performance of 657.0 mAh/g at 5 A/g. This work proves that modulation of rGO from the GO with different oxygen-containing functional groups lead to enhanced ionic conductivity, cyclic stability, and rate capability of the Si/rGO electrodes. [Display omitted] • A series of silicon/reduced graphene oxide (Si/rGO) was fabricated with different graphene oxide (GO). • Larger defects, and better electrical conductivity of rGO-3 promote the electrochemical performance of Si/rGO-3. • Si/ rGO-3 achieves high initial coulombic efficiency and excellent cycling performance. [ABSTRACT FROM AUTHOR]

Chemical warfare agents (CWA) can poison people through the skin and cause injury, and the use of chemical protective clothing (CPC) is an important way to protect personnel from injury. CPC performance strongly depends on chemical protective materials, and satisfactory protective materials must meet various requirements, including protective performance, physiological comfort, mechanical performance, and cost effectiveness. Here, low-cost materials were used to prepare PVDF sodium sulfonate composite membranes with different contents of modified graphene oxide (GO-SSS). Their tensile properties, contact angle, permeability, and selectivity were tested and analyzed. The results show that when the addition ratio of GO-SSS to the bare membrane is 0.5%, the composite membrane has desirable permeation selectivity of water vapor/CWA simulant vapor and desirable mechanical properties. Hence, our sodium sulfonate composite membrane of PVDF with GO-SSS is an ideal material for potential applications in CPC. [ABSTRACT FROM AUTHOR]

This study aims at the functionalization of magnetic graphene oxide nanosheets and the binding of humic acid as a lead complex ligand. Graphene oxide nanosheets possess a large surface area and various carboxylic acid groups which can be activated easily by activating agents. Therefore, they are suitable to be used for the extraction of heavy metals. To have a better process of extracting lead ions, magnetic graphene oxide was used in this research. Humic acid, as a lead metal complex agent, has an amine functional group which can be bound to modified graphene oxide from one side. The process of constructing the nano-adsorbent proposed for the preconcentration of lead ions as well as its characterization was studied by infrared spectroscopy (IR), ultraviolet–visible spectroscopy (UV–visible), field emission scanning electron microscopy (FESEM), and vibrating sample magnetometry (VSM). The designed nano-adsorbent was tested to measure lead ions in simulated and real samples of sea water, fish, and oysters. The detection limit obtained in the simulated samples was 0.07 μg/L, and the linear range was 0.2–12 μg/L. The apparatus used to measure the ions was a flame atomic absorption device. In the analysis of the real samples, the values obtained through flame atomic absorption were compared with those obtained through furnace atomic absorption. The proposed technique is advantageous due to being cheap, precise, and sensitive for the trace measurement of lead ions. [ABSTRACT FROM AUTHOR]

A waterborne epoxy coating with superior corrosion resistance was developed by using a novel amino-functionalized graphene oxide (GO) that was modified by 2,5-diaminobenzenesulfonic acid. A battery of characterization methods, such as Fourier transform infrared spectroscopy (FT-IR), Raman spectra, X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM), was used to prove that DGO was successfully prepared by grafting the amino of 2,5-diaminobenzenesulfonic on GO. The results indicated that the surface of DGO became rougher than GO, but a complete sheet structure was still maintained after modification; the optimal modified GO could be achieved when the mass ratio of 2,5-diaminobenzenesulfonic acid and GO was 5:1. The electrochemical impedance spectroscopy (EIS) tests indicated that the impedance at 0.01 Hz of a coating with 0.2 wt.% DGO still remained at a relatively high value after immersion for 48 h in 3.5 wt.% NaCl, which was about one order higher than a pure waterborne epoxy resin coating, and the corrosion current density decreased from 3.76 × 10−11 A/cm2 to 3.62 × 10−12 A/cm2. The dry adhesion and wet adhesion increased to 1.90 and 1.22 MPa, respectively, and the adhesion loss decreased from 53% to 36%. These interesting features could make waterborne epoxy coatings a promising anticorrosion coating for metal in long-term protection.

In this research, zinc (II)‐substituted Keggin‐type polyoxometalate [(C4H9)4N] PZnW11O39 (PZnW11) was prepared and stabilized on the modified graphene oxide (m‐GO) for removal of methyl red (MR) dye from aqueous solution. The maximum dye degradation and significance of variables on the decolorization system in static conditions were determined using response surface methodology (RSM). The main variables affecting the decolorization performance on dye decolorization, including system temperature (25–40°C), catalyst amount (0.001–0.005 g), and irradiation time (5–25 min), were evaluated. The optimum temperature, catalyst applying amount, and irradiation time were identified as 35°C, 0.003 g, and 20 min, respectively, and the experimental dye removal value was 96.8%. The high regression coefficient between the response and the variables (R2 = 0.9335) showed a good investigation of the experimental results by regression‐based polynomial model. In comparison with the previously reported photocatalytic decolorization systems, the dye removal system suggested in this work is quick, easy and involves a small amount of catalyst. Polyoxometalate‐based photocatalyst (PZnW11/m‐GO) shows potent visible‐light photocatalytic activity for the decolorization of methyl red dye, due to the generates the strong oxidants hydroxyl radical (OH) and superoxide anion radical (O2−) via photoelectrochemical decomposition of H2O and O2 in the presence of visible light irradiation. Efficient decolorization and degradation of organic contaminants by synthesized catalyst PZnW11/m‐GO suggest its potential for real industrial applications in removal of synthetic dye wastewater. [ABSTRACT FROM AUTHOR]

Summary: Modified graphene oxide (GO) nanosheets as fillers within poly(ether‐b‐amid) (PEBA) copolymer as matrix were used for mixed matrix membranes (MMMs) fabrication to improve CO2 capture. The GO nanosheets were modified by polypyrrole (PPy) and zinc cations. The former that have conjugated N‐containing groups provided a high degree of affinity toward CO2, and the latter has facilitated the gas molecules transport through the gas channel passages. The different modified GO nanosheets were characterized by HRTEM, FT‐IR, FESEM, XRD, and XPS analyses. Also, the FT‐IR, XRD, AFM, and SEM methods were used for the structural and morphological characterizations of the prepared MMMs with 0.1 wt% of the nanofiller. Gas permeation tests for CH4, N2, and CO2 were then performed for all prepared membranes. Compared to the neat PEBA membrane, the selectivity of both CO2/CH4 and CO2/N2 for PEBA‐GO‐PPy membrane increased up to 62% and 51% and for the PEBA‐GO‐PPy‐Zn membrane increased up to 58% and 56%, respectively. Furthermore, the PEBA‐GO‐PPy‐Zn disclosed a 10% increase in permeability of CO2 than the neat membrane. For PEBA‐GO‐PPy MMM, the permeability of CO2 was 122.4 Barrer, and the selectivity of CO2/CH4 and CO2/N2 was 29.8 and 122.5, respectively. Moreover, the gas separation results for PEBA‐GO‐PPy‐Zn MMM were about 131.8 Barrer for CO2 permeability and 30.7 and 119.2 for CO2/CH4 and CO2/N2 selectivities, respectively. Besides, the CO2/N2 selectivity of PEBA‐GO‐PPy and PEBA‐GO‐PPy‐Zn overcomes the Robeson's upper bound. [ABSTRACT FROM AUTHOR]

Copyright of Materials & Technologies / Materiali in Tehnologije is the property of Institute of Metals & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

VO(acac)2 and the in situ generated VO(Salen) complex were immobilized on the covalently modified graphene oxide (GO) with ethylenediamine (en) and designated as VO(acac)2@en‐GO and VO@Salen@en‐GO, respectively. Characterization of the prepared compounds was carried out with FT‐IR, XRD, ICP, CHN, Raman, SEM, TEM, and BET techniques. The SEM results confirmed the formation a nanofiber network and nanointerconnected needles. The prepared immobilized complexes were then used as heterogeneous catalysts for epoxidation of some allyl alcohols such as geraniol, trans‐2‐hexene‐1‐ol, and 1‐octen‐3‐ol. Based on the results obtained by GC and GC–mass analyses, epoxidation of geraniol with 97% conversion and 100% selectivity seemed promising. Readily recycling of the catalyst and reusing for four successive catalytic runs without significant loss of activity revealed that this catalysis system deserves nomination for practical application. [ABSTRACT FROM AUTHOR]

Carbon nanomaterials possess antioxidant properties that can be applied in biomedicine and clinics for the development of new highly effective treatments against oxidative stress-induced diseases like ischemic heart disease. We previously reported the usage of graphene oxide (GrO) as a precursor for the elaboration of such prototypes. The promising findings led to the development of two new modifications of GrO: nitrogen-doped (N -GrO) and l -cysteine functionalized (S -GrO) derivatives as possible antioxidant agents in ischemia-reperfusion (I/R) conditions. In this study, the cardioprotective and antioxidant potential of modified GrO as a pre-treatment in rats was evaluated for the first time. In Langendorff isolated rat heart I/R model, the left ventricle developed pressure (LVDP), the end-diastolic pressure (EDP), the maximal (dP/dt max) and minimal (dP/dt min) value of the first derivative of LVDP, and heart rate (HR) were measured. The oxidative-nitrosative markers, in particular, the rate of O 2 *- and H 2 O 2 generation, the content of malonic dialdehyde, diene conjugates, and leukotriene as well as cNOS and iNOS activity were estimated. Obtained results show a significant restoration of cadiodynamic parameters at the reperfusion period. Simultaneously, all samples significantly reduced the rate of reactive oxygen species (ROS) and lipid peroxidation markers in cardiac homogenates and preserved cNOS activity at the preischemic level. This evidence makes GrO derivatives promising candidates for the correction of reperfusion disorders affecting myocardial function. [Display omitted] • Nitrogen/sulfur-containing GrO effectively prevents post-ischemic disturbances. • GrO derivatives inhibit non-effective oxygen utilization by ischemized myocardium. • Free radical scavenging by GrO's derivatives proceed via different mechanisms. • Modified GrO samples are prospective drugs for ischemia/reperfusion injury treatment. [ABSTRACT FROM AUTHOR]

[Display omitted] • Introducing a novel adsorbent through graphene oxide and gallic acid. • High efficiency and cost-effective of the adsorbent with five regenerations. • Isotherm and kinetic studies of the process with superior accuracy. • Suggesting two mechanisms to synthesize the adsorbent and the process. • Developing the process using machine learning. In this work, silver ions were removed using modified graphene oxide (GO) with Gallic Acid (GA). Properties of GO/GA composites were characterized using Fourier transform infrared spectroscopy (FT-IR), Scanning electron microscope (SEM), X-ray diffraction (XRD), and Thermal Gravity Analysis (TGA). The effects of experimental parameters such as pH, adsorbent dosage, contact time, and initial concentrations of silver on the adsorption treatment of Ag (I) ions were investigated. Results indicated the optimum condition (98.35 % adsorption) was achieved at pH = 7, 25 mg of adsorbent, a time of 60 min, and an initial concentration of 50 ppm at 25 °C. Langmuir and Dubinin-Radushkevich isotherm models could reasonably interpret the adsorption data. In addition, the pseudo-second-order model appropriately described the kinetics of the adsorption process. Moreover, suggested mechanisms of modified adsorbent and the process were introduced. Finally, this work was compared with others, and all experimental data at different conditions were forecasted through machine learning. [ABSTRACT FROM AUTHOR]

Graphene oxide, as a new two-dimensional material, has a large specific surface area, high thermal stability, excellent mechanical stability and exhibits hydrophilic properties. By combining the carboxyl groups on the surface of graphene oxide with hydrophilic groups, surfactant-like polymers can be obtained. In this paper, based on the molecular dynamics method combined with the first nature principle, we first determine the magnitude of the binding energy of three different coupling agents—alkylamines, silane coupling agents, and haloalkanes—and analytically obtain the characteristics of the soft reaction. The high stability of alkylamines and graphene oxide modified by cetylamine, oil, and water models was also established. Then, three different chain lengths of simulated oil, modified graphene oxide–water solution, and oil-modified graphene oxide–water systems were established, and finally, the self-aggregation phenomenon and molecular morphology changes in modified graphene oxide at the oil–water interface were observed by an all-atom molecular dynamics model. The density profile, interfacial formation energy, diffusion coefficient and oil–water interfacial tension of modified graphene oxide molecules (NGOs) at three different temperatures of 300 K, 330 K, and 360 K were analyzed, as well as the relationship between the reduced interfacial tension and enhanced oil recovery (EOR).

Abstract In this study, mixed matrix membranes (MMMs) consisting of graphene oxide (GO) and functionalized graphene oxide (FGO) incorporated in a polymer of intrinsic microporosity (PIM-1) serving as a polymer matrix have been fabricated by dip-coating method, and their single gas transport properties were investigated. Successfully surface-modified GOs were characterized by Fourier transform infrared spectroscopy (FTIR), UV-Vis spectroscopy, Raman spectroscopy, scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). The effect of FGO loading on MMM morphology and performance was investigated by varying the FGO content in polymer matrix from 9 to 84 wt.%. Use of high FGO content in the polymer matrix helped to reveal difference in interaction of functionalized fillers with PIM-1 and even to discuss the change of FGO stiffness and filler alignment to the membrane surface depending on functional group nature.

An effective, sensitive, relatively fast, and cost-effective method was developed to determine two types of selected organophosphorus pesticides (OPPs) including diazinon and chlorpyrifos in apple, peach, and four different water samples (river, sea, well, and agriculture wastewater samples) through applying poly(amidoamine)@graphene oxide-reinforced polyvinylidene difluoride thin-film microextraction (PAMAM@GO-PVDF-TFME). The extracted analytes were desorbed via organic solvent and determined using high-performance liquid chromatography-ultraviolet detection (HPLC-UV). The strong interactions between the sorbent and selected analytes (coordination bonds, intermolecular hydrogen bonding, π-π interactions, and hydrophobic effects) made this TFME capable of high extraction performance and capacity. Several factors involved in the PAMAM@GO-PVDF-TFME experiments such as desorption volume, desorption time, sample pH, extraction time, and stirring rate were screened via Plackett-Burman design and then optimized through Box-Behnken design with the purpose of reaching the highest extraction efficiency. The above method showed a good linear range (0.5-500 μg L−1 and 1-500 μg L−1) with the coefficient of determination better 0.9944, low limits of determination (0.12 and 0.20 μg L−1), good enrichment factors (99 and 98), acceptable extraction recoveries (99 and 98%), and good spiking recoveries (90-98%) under the optimized condition at three different spike levels for chlorpyrifos and diazinon, respectively. The results confirmed that the presented method would be promising for the determination of various types of these pesticides in environmental and beverage samples. [ABSTRACT FROM AUTHOR]

A magnetic composite was synthesized using palm kernel shell-based activated carbon, graphene oxide (GO) and iron oxide. The morphology, textural properties, magnetic properties, crystal structure and functional groups of the composite were studied. The characterization shows the successful formation of the ternary composite with a high specific surface area (280.39 m2/g) and abundant surface functional groups. The magnetic properties of the composite indicate a saturation magnetization of 33.72 emu/g, signifying that the composite can be easily separated with an external magnetic field. The performance of the composite was then investigated through the removal of an anionic azo dye, Acid Blue 113, from aqueous solution. The effect of initial pH of the solution, adsorbent dosage and adsorption contact time was studied. The composite achieved an adsorption capacity of 32.2 mg/g and 96.3% dye removal. Effective dye removal was still achieved after five cycles of adsorption-regeneration, with the dye removal of 74% after the fifth cycle. The analyses of adsorption isotherm and kinetics show that the adsorption process fits pseudo-second-order kinetic and Langmuir isotherm models, indicating a monolayer chemisorption process. The excellent adsorption performance and reusability of the composite and its magnetic separability signify its potential as an adsorbent for wastewater treatment. [ABSTRACT FROM AUTHOR]

The filler that could enhance the T peel strength of adhesive was prepared using graphene oxide (GO) grafted with toluene diisocyanate (TDI) and amino terminated poly(butadiene‐acrylonitrile) (ATBN). As a result of structure characterization, the ATBN‐TDI‐GO structure with dissociated ‐NCO groups was built. The T peel strength of the adhesive containing 25 wt% ATBN, 17 wt% TDI, and 0.5 wt% GO increased to 18.47 N/mm, which increased by 4.75 times compared with pure epoxy resin (EP), and other mechanical properties of the adhesive were enhanced. The reason for the increasing of bonding properties was chemical bonding built between the adherent and the adhesive by the surplus ‐NCO groups provided by the ATBN‐TDI‐GO filler. The effect of physical adsorption provided by ATBN and the chemical bonding between the matrix resin and ATBN‐TDI‐GO filler also could toughen the EP resin. The design of the EP filler could provide a new method for adhesive manufacture. [ABSTRACT FROM AUTHOR]

BACKGROUND The current study suggests an experimental and modeling approach for the adsorptive removal of lead(II) ions from contaminated water sample. The Schiff base reagent, bis(salicylaldehyde)ethylenediimine (Salen) functionalized graphene oxide (GO) was applied as adsorbent. Salen functionalized GO was prepared and characterized using scanning electron microscopy (SEM), energy dispersive X‐ray spectroscopy (EDX), X‐ray diffraction (XRD), Fourier‐transform infrared (FTIR) spectroscopy, zeta potential and dynamic light scattering (DLS) techniques. The batch experiment represented maximum removal efficiency of 99% at pH 6.5, adsorbent dose of 100 mg L−1 and 5 min contact time. RESULTS: The residual concentration of lead(II) after removal was measured using flame atomic absorption spectrometry. DLS results suggested slightly smaller particle size of Salen modified GO than pristine GO. The optimized model calculated with Gaussian 09 W software showed maximum total energy (1.3959 eV) and dipole moment (6.8646 D) for model of lead interaction with Salen–GO. The Langmuir adsorption isotherm model was most fitted and the kinetic data indicated that the lead(II) adsorption on Salen–GO followed second‐order model. The maximum adsorption capacity calculated was 68 mg g−1. CONCLUSION: The adsorbent was applied to remove lead(II) ions in real contaminated water samples of the battery manufacturing industry with average removal of 95% with relative standard deviation 1.23% (n = 3). The adsorbent was reusable with desorption of lead(II) from adsorbent and was 95% with 0.2 mol L‐1 nitric acid. © 2020 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Due to the widespread use of nanocarbon materials (NCMs), more researchers are studying their tribological performances. In this work, the tribological behaviors of the following five types of NCMs with different geometric shapes were evaluated in a novel oil-in-water system: spherical fullerenes (C60, 0D), tubular multi-walled carbon nanotubes (MWCNT, 1D), sheet graphene oxide (GO, 2D), sheet graphene oxide derivative (Oct-O-GO, 2D), and lamellar graphite (G, 3D). Among these, GO with two types of oxidation degrees, i.e., GO(1), GO(2), and Oct-O-GO(1) were synthesized and characterized using Fourier-transform infrared spectroscopy, Raman spectroscopy, x-ray diffraction, thermogravimetric analysis, scanning electron microscopy, and contact angle measurements. The load-carrying capacity of the NCM emulsions were evaluated using a four-ball test machine, and the lubrication performances were investigated using a high-frequency reciprocating friction and wear tester with a sliding distance of 1,800 mm under different loads (50 N and 100 N) at 0.5 Hz. The results revealed that the Oct-O-GO(1) emulsion exhibited the best load-carrying capacity, and the best friction-reducing and anti-wear properties compared to other emulsions. Moreover, the anti-wear advantage was more prominent under high load conditions, whereas the other emulsions exhibited a certain degree of abrasive or adhesive wear. The lubrication mechanism was determined through the analysis of worn surfaces using scanning electron microscopy/energy-dispersive x-ray spectroscopy, micro-Raman spectroscopy, and x-ray photoelectron spectroscopy. The results revealed that during frictional sliding, the ingredients in the emulsion can absorb and react with the freshly exposed metal surface to form surface-active films to protect the surfaces from abrasion. Moreover, it was found that the higher the amount of ingredients that contain alkyl and O-H/C=O, the better was the lubrication performance in addition to an increase in the carbon residue in the tribofilm generated on the meal surface. [ABSTRACT FROM AUTHOR]

Advanced materials for the efficient treatment of textile wastewater need to be developed for the sustainable growth of the textile industry. In this study, graphene oxide (GO) was modified by the incorporation of natural clay (bentonite) and mixed metal oxide (copper-cobalt oxide) to produce GO-based binary and ternary composites. Two binary composites, GO/bentonite and GO/Cu–Co Ox (oxide), and one ternary composite, GO/bentonite/Cu–Co Ox, were characterized by Fourier transform-infrared spectroscopy (FTIR), scanning electron microscope (SEM), energy dispersive spectrometer (EDS) and Brunauer-Emmett-Teller (BET) analysis. The adsorption efficiency of these composites was evaluated against a cationic dye, Basic Blue 41 (BB41). The composites had several surface functional groups, and the ternary composite had tubular porous structures formed by the cross-linking of the bentonite and GO planes. The BET surface area of the ternary composite was 50% higher than that of the GO. The BB41 removals were 92, 89, 80, and 69% for GO/bentonite/Cu–Co oxide, GO/bentonite, GO and GO/Cu–Co oxide, respectively. The pseudo-2nd-order and intraparticle diffusion models best describe the kinetics results, indicating chemisorption and slow pore diffusion-controlled adsorption processes. The Langmuir isotherm-derived adsorption capacity of GO/bentonite/Cu–Co oxide was 351.1 mg/g, which was very close to the measured value. After five consecutive cycles, the ternary composite retained 90% BB41 removal efficiency compared to its 1st cycle. Electrostatic interaction and pore diffusion were predicted to be the controlling mechanisms for the adsorption of the BB41. The GO-based ternary composite can be a feasible and scalable adsorbent for BB41 in wastewater treatment. [Display omitted] • Graphene oxide (GO) was intercalated into bentonite layers, with crumpled and tubular pore structures. • Carboxylic, hydroxyl, epoxide, and carbonyl groups were present on GO/bentonite/Cu–Co oxide (Ox). • GO/bentonite/Cu–Co Ox has 40 and 50% greater surface area and adsorption capacity than GO. • GO/bentonite/Cu–Co Ox retained ∼90% efficiency after 5 consecutive cycles compared to the 1st cycle. • Kinetics studies: chemical interaction dominated the adsorption process for basic blue 41 (BB41). [ABSTRACT FROM AUTHOR]

Thin-film composite mixed matrix membranes (CMMMs) were fabricated using interfacial polymerization to achieve high permeance and selectivity for CO2 separation. This study revealed the role of substrate properties on performance, which are not typically considered important. In order to enhance the affinity between the substrate and the coating solution during interfacial polymerization and increase the selectivity of CO2, a mixture of polyethylene glycol (PEG) and dopamine (DOPA) was subjected to a spinning process. Then, the surface of the substrate was subjected to interfacial polymerization using polyethyleneimine (PEI), trimesoyl chloride (TMC), and sodium dodecyl sulfate (SDS). The effect of adding SDS as a surfactant on the structure and gas permeation properties of the fabricated membranes was examined. Thin-film composite hollow fiber membranes containing modified graphene oxide (mGO) were fabricated, and their characteristics were analyzed. The membranes exhibited very promising separation performance, with CO2 permeance of 73 GPU and CO2/N2 selectivity of 60. From the design of a membrane substrate for separating CO2, the CMMMs hollow fiber membrane was optimized using the active layer and mGO nanoparticles through interfacial polymerization.

Adding inorganic fillers to polymer electrolytes is one of the main means to improve ionic conductivity. However, the filler will aggregate, causing the problem of incompatibility between the electrolyte and the metal lithium negative electrode. According to reports, the flaky structure of graphene oxide (GO) has the characteristics of large specific surface area and stable performance, which has attracted widespread attention as a filler for polymer electrolytes. However, the electrolyte membrane has poor compatibility with lithium negative electrodes when GO as a filler, which is not conducive to the full performance of lithium batteries. In this paper, we grafted polyethylene oxide (PEO) on the surface of GO (the product is referred to as GO@PEO) to improving the dispersibility of the filler and the compatibility of the gel polymer electrolyte (GPE) with lithium metal . It is worth that after GO grafting PEO, the impedance of the interface between GPE and lithium metal is significantly reduced, and the compatibility of the electrolyte with the lithium negative electrode is significantly improved. Assembled into Li/ Li battery, the surface current cycle is stable, up to 1 mA cm ^−2 . GO@PEO further improves the ionic conductivity of the ion conductivity up to 1.6 mS cm ^−1 . Further prepared into LiFePO _4 (LFP)/Li battery, GPE-GO@PEO showed excellent cycle stability and the discharge specific capacity retention rate was 95.6% after 100 cycles. The rate performance of the battery is also significantly improved. At 5C, the discharge specific capacity of the LFP/Li battery remains 40 mAh g ^−1 .

• Alkane chain was introduced into GO nanosheets by amidation of GO with DDA. • There were outstanding compatibility and strong interface interaction between GO-DDA and CIC-23 matrix. • The GO-DDA/CIC-23 composite coating had excellent corrosion resistance and anti-aging property. A modified graphene oxide (GO-DDA) obtained by the amidation reaction of graphene oxide (GO) with dodecylamine (DDA) is used to prepare GO-DDA/aircraft structural corrosion inhibiting compounds (CIC-23) composite coating to enhance the effectiveness and usability of CICs. The corrosion property is investigated by electrochemical tests and metallographic microscope, and the anti-aging property is studied by accelerated UV-condensation exposure experiments. Owing to the abundant alkane chains, GO-DDA has good compatibility with CIC-23 matrix, providing the composite coating with favourable barrier property and corrosion resistance property. The GO-DDA/CIC-23 (1.2%) composite coating possesses the best corrosion resistance (E corr : 0.063±0.0002 V, I corr : (7.24±0.02)E-08 A/cm², PE %: 99.67±0.31%, and R p : (1.51±0.004)E06 Ω cm2) among all samples. Moreover, the GO-DDA/CIC-23 (1.2%) coating has the optimal aging resistance, because the strong interfacial interaction between GO-DDA and CIC-23 matrix can obviously hamper the growth of cracks and decrease the channel of corrosion media to the metal surface. This work can provide guidelines on the development of highly effective corrosion inhibiting compounds from aircraft structure. [ABSTRACT FROM AUTHOR]

• Tuning the graphene interlayer spacing through simultaneous addition of KCl and polymerization. • First time investigation on effect of KCl on desalination performance of the copolymerized GO/Nylon nanocomposite membrane. • Preparation of a highly active membrane in desalination via forward osmosis. In this research work, following the efforts for providing fresh water for humans, a novel nanocomposite membrane was prepared. In this regard, potassium cation was added to co-polymerized graphene oxide (GO) to tune the interlayer spacing of the GO nanosheets. The prepared membranes were characterized by X-ray diffraction, contact angle measurement, Atomic Force Microscopy (AFM), and Field emission scanning electron microscopy (FE-SEM) equipped with Energy-dispersive X-ray spectroscopy (EDX). The XRD patterns confirmed that by adding potassium chloride (KCl) to GO containing membranes, interlayer spacing was optimized and led to presence of interlayer spacing in the range of 4–6 Å and 7.80 Å which are highly active in rejection of salt ions. To evaluate the desalination performance of the prepared nanocomposite membranes, forward osmosis (FO) process was considered. The results showed that although the membrane showed acceptable permeability, the salt rejection activity was enhanced considerably. The potassium cation containing membrane exhibited reverse salt rejection of 2.03 which was 6.31 in absence of it. This can be attributed to effect of potassium cations in optimizing and modifying interlayer spacing along with repulsion of Na+ due to charge similarity with K+. [ABSTRACT FROM AUTHOR]

In this research work, following the efforts for providing fresh water for humans, a novel nanocomposite membrane was prepared. In this regard, potassium cation was added to co-polymerized graphene oxide (GO) to tune the interlayer spacing of the GO nanosheets. The prepared membranes were characterized by X-ray diffraction, contact angle measurement, Atomic Force Microscopy (AFM), and Field emission scanning electron microscopy (FE-SEM) equipped with Energy-dispersive X-ray spectroscopy (EDX). The XRD patterns confirmed that by adding potassium chloride (KCI) to GO containing membranes, inter- layer spacing was optimized and led to presence of interlayer spacing in the range of 4-6 Å and 7.80 Å which are highly active in rejection of salt ions. To evaluate the desalination performance of the prepared nanocomposite membranes, forward osmosis (FO) process was considered. The results showed that although the membrane showed acceptable permeability, the salt rejection activity was enhanced considerably. The potassium cation containing membrane exhibited reverse salt rejection of 2.03 which was 6.31 in absence of it. This can be attributed to effect of potassium cations in optimizing and modifying interlayer spacing along with repulsion of Na+ due to charge similarity with K+. [ABSTRACT FROM AUTHOR]

Abstract Synthesis of noble metal nanoparticles (NPs) on modified graphene oxide with biocompatible polymers has attracted significant due to their unique properties and various applications. In this research, covalent-modified graphene oxide (MGO) with diacid terminated poly (ethylene glycol) (PEG) was used as a substrate and stabilizing of Au (ш). The reduction of MGO-Au (ш) complex with hydrazine monohydrate under reflux condition obtained biocompatible reduced MGO (rMGO)-Au NPs. Diacid terminated PEG obtained from the reaction of PEG with succinic anhydride in the presence of N,N- dicyclohexylcarbodiimide (DCC) and 4-methylamino pyridine (DMAP) was attached to GO sheets to prevent from the aggregation of rMGO sheets and Au NPs. The resulting aqueous suspension was characterized through UV–vis, FT-IR, Raman, XRD, DLS-zeta potential, SEM, EDX and TEM. Furthermore, nanocomposite showed good catalytic behavior in Betti reaction- synthesis of 1-(α-aminoalkyl)-2-naphthols. The favorable properties of colloidal nanocomposite were attributed to the stable and well distribution Au NPs on rMGO. Graphical abstract Unlabelled Image Highlights • Modification of PEG with anhydride succinic to obtain diacid PEG • PEGylation of GO with MPEG • Synthesis of Au NPs on surface of reduced PEGylated GO (rMGO) • rMGO-Au NPs composite acted as a catalysis in Betti reaction. [ABSTRACT FROM AUTHOR]

Abstract A biohybrid material based on poly(lactic acid)(PLA) incorporated with low contents of polyethylene glycol (PEG) functionalized graphene oxide (GO) was prepared via melting process and their structure, morphology, mechanical performance, and thermal properties were studied in detail. SEM and TEM characterizations confirmed that the functionalization of GO with PEG (PEGmGO) promoted its exfoliation into thin exfoliated nanosheets, thereby improving the interactions between PEGmGO filler and PLA matrix at interface. FT-IR spectra showed the presence of strong polar and hydrogen bonding interactions between components in the biohybrid. Mechanical and thermal tests indicated that there was the significant improvement of the stiffness, strength, and thermal stability of such biohybrid material with the addition of 0.3 phr PEGmGO, as compared to pure PLA, PEG-plasticized PLA, PEG-plasticized PLA/GO, and other surveyed PEG-plasticized PLA/PEGmGO biohybrids. This behavior was attributed to the homogeneous dispersion of the PEGmGO nanofillers within PLA matrix along with their strong interfacial interaction. The as-obtained biohybrids show highly potential to be useful in the bioengineering applications. [ABSTRACT FROM AUTHOR]

A highly improved strategy is established in order to systematically integrate excess exfoliated graphene oxide (GO) as fillers into polyacrylonitrile (PAN) nanofibers via electrospinning. Simple modification of GO surface allowed for their loading efficiency into the nanofibers to surpass the typical limits. Among many features, the hydrophilic and mechanical properties of these membranes were found to be significantly increased compared to the original PAN and bare GO-loaded membranes probably due to the effective reinforcing filler effect caused by the even distribution of the modified GO within the PAN nanofibers. Thus, the simple surface modification of fillers can facilitate the capability of controlling the loading efficiency into electrospun nanofibers which can highly impact the quality and performance of final composite membranes. [ABSTRACT FROM AUTHOR]

Graphene oxide (GO) and its derivatives have been applied to the humidity sensing area in recent years due to its abundant hydrophilic functional groups, and proved to be ultrasensitive to the humidity changing. But the stability of the sensors is always an obstacle to their application. Besides, the long-term linearity is seldom studied. In this work, diamine modified GO (MGO) has been synthesized and mixed with Nafion polymer to form a hybrid film, and applied to the humidity sensors. We have applied two measurement methods by either fitting of the impedance spectra to extract charge transfer resistance (R ct ) or measurement of the impedance under a certain frequency, to evaluate the response to the relative humidity (RH). Both MGO and its composite show good sensitivity to the RH under the two testing methods The R ct shows good linearity at the full testing RH range even after two months, while the impedance under a certain frequency can’t keep the linear response to the RH after certain period of time. The addition of Nafion decreases the R ct and increases the sensitivity of MGO based sensor. Linearity of the sensor is improved by the combination of MGO and Nafion. Long-term testing results show the linearity of the composite sensors changes over time but always keeps a better linearity than the pure MGO sensor. [ABSTRACT FROM AUTHOR]

In current work, nanoconfinement effect of graphene nanoplatelets on properties of matrix-grafted graphene/polysulfide polymer nanocomposites is investigated. To this end, graphene oxide (GO) is modified with (3-chloropropyl)triethoxysilane (CPTES) to be able to participate in interfacial polymerization of 1,2-dichloroethane (DCE), 1,2,3-trichloropropane (TCP) as crosslinker and disodium tetrasulfide (Na 2 S 4 ). Successful modification of GO is proved by FT-IR and Raman spectroscopies, TGA, XRD, and TEM. Different amounts of modified GO (mGO) (0.0, 0.1, 0.3, 0.5, 0.7, and 1.0 wt%) are used to prepare nanocomposites. Nanoconfinement effect of graphene nanoplatelets on the crystallinity of synthesized nanocomposites is investigated by XRD and DSC. Results showed that crystallinity of nanocomposites increases by adding graphene up to 0.7 wt% while after that crystallinity decreases. Also, DSC results showed that glass transition temperature (T g ) and melting point (T m ) of nanocomposites depend strongly on the amount of used mGO and pass through a maximum by increasing graphene content. According to TGA results, all nanocomposites were more thermally stable than neat polymer and decomposed in two stages where an optimum amount of mGO exists to investigate the highest thermal stability. [ABSTRACT FROM AUTHOR]

The low surface activity of graphene oxide (GO) stemming from its large conjugated electronic structure can easily affect the dispersion behavior of GO-based polymer matrices. This significantly undermines the properties of the resulting composite materials. Therefore, in order to increase the GO surface activity for use in polymer-based composites, GO was modified using silane coupling agent which was then doped into polydimethylsiloxane (PDMS) polymer to prepare novel paints by sol-gel reaction strategy. The subsequent novel composite coatings based on PDMS/modified GO (mGO) were finally cured with tetraethoxysilane as the hardening agent in the presence of dibutyltin dilaurate catalyst. The effect of doping mGO into PDMS polymer was systematically studied using infrared spectroscopy, micro-Raman spectroscopy, TEM, SEM, XRD, TGA, mechanical test, thermal conductivity test, and the erosion resistance test. It was concluded that the phase compatibility between GO and PDMS was enhanced due to the new interconnecting chemical bonds brought about by the mGO in the composite. [ABSTRACT FROM AUTHOR]

This work describes a novel nanofiltration membrane fabrication strategy in which the octadecylamine-grafted GO with the organophilic property is incorporated in organic phase during interfacial polymerization (IP) in order to protect the polyamide backbone from the attack of free chlorine. Meanwhile, the aqueous phase containing mixed amines of piperazine (PIP) and the fluorine-containing monomer (2,2′-bis(1-hydroxyl-1-trifluoromethyl-2,2,2-triflutoethyl)-4,4′-methylenedianiline, BHTTM) enables further improvement in chlorine resistance of the thin film nanocomposite (TFN) membrane. The modified GO was systematically characterized by TEM, FT-IR, TGA and XRD. And the membrane properties were investigated by XPS, TEM, AFM and dynamic contact angle. The octadecylamine-grafted GO TFN membrane (TFNMA-GO-ODA) exhibits measurably smoother and less hydrophilic surface compared to TFC membrane with mixed amines as well as the similarly fabricated GO TFN membrane. The TFNMA-GO-ODA demonstrated a pure water flux of 49.6 L m −2 h −1 (0.6 MPa), which was nearly 2.5 times than that of pristine PIP TFC membrane and 1.6 times than that of mixed-amine TFC membrane, while keeping high Na 2 SO 4 rejection of 98.4%. More importantly, the TFNMA-GO-ODA presented excellent chlorine resistance, benefiting from the existence of fluorine-containing groups in BHTTM and the protective effect of stable graphene nanosheets. The results indicate great potential of such membrane in water desalination and purification in industrial scale. [ABSTRACT FROM AUTHOR]

In this study a new melamine-terephthaldehyde resin modified graphene oxide was synthesized and used as a reinforcement of poly(vinyl chloride) (PVC). Characterization, morphology, thermal and mechanical properties of the nanocomposites were examined by means of attenuated total reflectance-Fourier transform infrared spectroscopy, X-ray diffraction, field emission-scanning electron microscopy, thermogravimetric analysis, differential scanning calorimeter and tensile properties. The first hydrochloric acid releasing data of poly(vinyl chloride) was removed by incorporation of the modified graphene oxide as compare to the neat polymer. The temperatures at 2 wt% losses, main decomposition temperatures, maximum decomposition temperatures, also shift to higher temperature in the corresponding nanocomposites as compared to the neat PVC. The tensile strength and elongation at break of the nanocomposite films was increased as compared to the neat PVC. The interesting results in crystallinity of PVC were observed with adding 5 wt% of the modified graphene oxide. [ABSTRACT FROM AUTHOR]

In this research, a new type of chemically modified graphene oxide (GO) was synthesized based a silane ligand and then used as substrate and stabilizing for the synthesis of monodispersed and small Ag nanoparticles (NPs). First, ligand molecules were successfully grafted onto the surface of GO (LGO) and then, active groups of LGO could effectively interact with Ag ions. The reduction of Ag ions and LGO sheets was carried out by hydrazine under reflux. The resulted nanocomposite was fully characterized by different techniques. Furthermore, the antibacterial behavior of nanocomposite was studied against E. coli and S. aureus . The results showed that nanocomposite exhibits good antibacterial activity against E. coli and S. aureus and also S. aureus showed greater resistance than the E. coli strains against the LG/Ag nanocomposite. [ABSTRACT FROM AUTHOR]

Methylated DNA is a covalent post-translational modification, which plays a crucial role in pathological and physiological processes including several diseases, such as cardiovascular disease, diabetes or cancer. Despite that, methylated DNA presents a new generation of biomarkers, which brings a promising alternative for using in point-care diagnostic. Regarding this fact, DNA based electrochemical sensors enable fast, reliable, low-cost, time-consuming and efficient detection. The application of these biosensors as possible alternatives for the determination of methylated DNA is recently growing. Therefore, a biosensor for the determination of methylated DNA was fabricated. This study was aimed to develop an efficient biosensor, with an amplified electrochemical signal which is suited for the detection of the low-level concentration of methylated DNA. The bare gold electrode was first covered with the graphene oxide modified with gold, silver and copper nanoparticles. These composites have a strong affinity to DNA probe and their effect on the sensitivity and selectivity of the biosensor was investigated. The developed biosensor shows promising analytical characteristics with a wide detection linear range. The electrochemical impedance spectroscopy (EIS) was used to detect the hybridization of the DNA probe with methylated DNA target.

Sodium hydroxide-modified graphene oxide was used as manganese oxides support for the preparation of nanocomposites via a one-pot preparation route for the degradation of Reactive Black 5. The nanocomposites were characterized for their structure by X-ray diffraction, for their textural properties by Nitrogen adsorption, and for their surface chemistry by Fourier transform infrared spectroscopy, potentiometric titration, and thermal analysis measurements. The nanocomposites prepared showed to possess high activity for the degradation/oxidation of Reactive Black 5 at ambient conditions, without light irradiation, which was higher than that of the precursors manganese oxides and can be attributed to the synergistic effect of the manganese oxides and the modified graphene oxide.

A highly improved strategy is established in order to systematically integrate excess exfoliated graphene oxide (GO) as fillers into polyacrylonitrile (PAN) nanofibers via electrospinning. Simple modification of GO surface allowed for their loading efficiency into the nanofibers to surpass the typical limits. Among many features, the hydrophilic and mechanical properties of these membranes were found to be significantly increased compared to the original PAN and bare GO-loaded membranes probably due to the effective reinforcing filler effect caused by the even distribution of the modified GO within the PAN nanofibers. Thus, the simple surface modification of fillers can facilitate the capability of controlling the loading efficiency into electrospun nanofibers which can highly impact the quality and performance of final composite membranes.

Graphene oxide (GO) was asymmetric chemically modified with myristyltrimethylammonium bromide (TTAB) to get modified graphene oxide (MGO). This MGO was used as an emulsifier and additive in oil-in-water emulsion. The emulsifying tests showed MGO greatly improved the stability of base emulsion and decreased its droplets size. Tribological test results showed that under the boundary lubrication condition with MGO-emulsion, the friction coefficient (COF) and the wear rate of the steel ball were decreased by about 18% and 48% respectively, comparing with base emulsion lubrication. The tribological mechanism of MGO-emulsion could be explained by the strong film-forming ability on the metal surface; the good lubricity of its small droplets; the formed adsorption film, transfer film and tribofilm between the contact surfaces. [ABSTRACT FROM AUTHOR]

Graphene oxide (GO) acted as an inorganic filler has attracted great attention in the construction of polymer-based composite coating film. Nevertheless, the high surface area, obvious van der Waals forces, and abundant hydrophilic groups of GO result in its poor dispersion behavior and compatibility in hydrophobic polymer, which greatly limits its widespread practical application. To solve the above issue, we have prepared SiO 2 -decorated GO (GO-SiO 2) nanoparticles using the sol-gel hydrolysis method. The FTIR, Raman spectra, XPS and SEM analysis displayed that GO-SiO 2 nanoparticles were successfully constructed and the SiO 2 nanoparticles are covalently grafted onto GO sheet surfaces. Moreover, the GO-SiO 2 nanoparticles are further employed as inorganic fillers into the non-solvent UV-curable castor oil-based polyurethane acrylate (COPUA) systems for the preparation of composite coating films. Herein, the GO-SiO 2 nanoparticles can be uniformly dispersed in hydrophobic COPUA-based coating precursor, and have favorable compatibility with COPUA resin. The incorporation of GO-SiO 2 nanoparticles into the coating film matrix would slightly decrease the gel content of coating films (all gel contents are above 91.5 %) while improving the hydrophobic property of coating films. Furthermore, the thermal stability and mechanical performance of coating films have reasonably enhanced trends by the incorporation of GO-SiO 2 nanoparticles. The prepared coating films display favorable acid, alkali, and solvent resistance, and the high content of GO-SiO 2 nanoparticles is beneficial to aggrandize the anticorrosion performance of coating films. This work provides a universal approach to modify GO sheets and construct multifunctional modified GO/polyurethane composite film for coating application. [Display omitted] • SiO 2 -decorated GO sheets (GO-SiO 2) are prepared by the sol-gel hydrolysis method. • GO-SiO 2 has nice suspendability and compatibility in hydrophobic coating system. • GO-SiO 2 /castor oil-based polyurethane film is formed by non-solvent UV-curing way. • GO-SiO 2 avails to enhance thermal, mechanical and anticorrosive properties of film. • This work provides a facile method to prepare GO/polyurethane-based coating film. [ABSTRACT FROM AUTHOR]