Improvement of polyacrylonitrile ultrafiltration membranes' properties using decane-functionalized reduced graphene oxide nanoparticles

2016 ◽  
Vol 16 (5) ◽  
pp. 1378-1387 ◽  
Author(s):  
Reyhaneh Kaveh ◽  
Zahra Shariatinia ◽  
Ahmad Arefazar
Keyword(s):  
Electron Microscopy ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Water Flux ◽  
Superior Performance ◽  
Oxide Nanoparticles ◽  
Ultrafiltration Membranes ◽  
Reduced Graphene ◽  
Maximum Water ◽  
Scanning Electron

The effect of decane-functionalized reduced graphene oxide (decane-rGO) was studied on the performance of polyacrylonitrile (PAN) ultrafiltration membranes. The results showed that the decane-rGO/PAN membranes had greater salt rejections relative to their corresponding GO/PAN membranes, confirming superior performance of modified decane-rGO particles. Also, the membrane with 0.2 wt% decane-rGO exhibited maximum water flux and appropriate salt rejection. The field-emission scanning electron microscopy (FE-SEM) micrographs illustrated that the sponge-like pores in the pristine PAN membrane were changed to a finger-like structure in the membrane containing up to 0.2 wt% of decane-rGO and the vertical holes were converted to horizontal holes by further increasing the decane-rGO concentration in the polymer matrix.

scholarly journals Reduced Graphene Oxide–Epoxy Grafted Poly(Styrene-Co-Acrylate) Composites for Corrosion Protection of Mild Steel

Coatings ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 666
Author(s):  
Xinchuan Fan ◽  
Yue Hu ◽  
Yijun Zhang ◽  
Jiachen Lu ◽  
Xiaofeng Chen ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Photoelectron Spectroscopy ◽  
X Ray Diffraction ◽  
Corrosion Properties ◽  
X Ray ◽  
Transmission Electron ◽  
Reduced Graphene ◽  
Scanning Electron

Reduced graphene oxide–epoxy grafted poly(styrene-co-acrylate) composites (GESA) were prepared by anchoring different amount of epoxy modified poly(styrene-co-acrylate) (EPSA) onto reduced graphene oxide (rGO) sheets through π–π electrostatic attraction. The GESA composites were characterized by Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). The anti-corrosion properties of rGO/EPSA composites were evaluated by electro-chemical impedance spectroscopy (EIS) in hydroxyl-polyacrylate coating, and the results revealed that the corrosion rate was decreased from 3.509 × 10−1 to 1.394 × 10−6 mm/a.

scholarly journals Facile and green synthesis of silver nanoparticle-reduced graphene oxide composite and its application as nonenzymatic electrochemical sensor for hydrogen peroxide

2021 ◽  
pp. 295-308 ◽  
Author(s):  
Jagdish C. Bhangoji ◽  
Srikant Sahoo ◽  
Ashis Kumar Satpati ◽  
Suresh S. Shendage
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Dynamic Range ◽  
Electrochemical Impedance ◽  
Metal Foil ◽  
Reduced Graphene ◽  
Scanning Electron

A simple and environment friendly protocol has been developed for the synthesis of Ag nanoparticles (AgNPs) supported on reduced graphene oxide (rGO) with copper metal foil as reductant. The prepared AgNPs-rGO, nanocomposite was characterized by various analytical techniques such as scanning electron microscopy (SEM), field-emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD). The electrochemical performance of the material has been evaluated using cyclic voltammetry (CV), chronoamperometry and electrochemical impedance spectroscopy (EIS). The average crystallite size of AgNPs is found to be 32.34 nm. The application of prepared electrocatalyst (AgNPs-rGO) as a non-enzymatic sensor is examined through the modified electrode with the synthesized AgNPs-rGO. The sensor showed excellent performance toward H2O2 reduction with a sensitivity of 12.73 µA.cm-2.mM-1, with a linear dynamic range of 1.5 µM – 100 mM, and the detection limit of 1.90 µM (S/N = 3). Furthermore, the sensor displayed high sensitivity, reproducibility, stability and selectivity for the determination of H2O2. The results demonstrated that AgNPs-rGO has potential applications as sensing material for quantitative determination of H2O2.

scholarly journals Microstructure and microwave absorbing properties of reduced graphene oxide/Ni/multi-walled carbon nanotubes/Fe3O4 filled monolayer cement–based absorber

2019 ◽  
Vol 11 (1) ◽  
pp. 168781401882288 ◽  
Author(s):  
Yafei Sun ◽  
Min Chen ◽  
Peiwei Gao ◽  
Tianshu Zhou ◽  
Hongwei Liu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Scanning Electron Microscopy ◽  
Graphene Oxide ◽  
Pore Structure ◽  
Reduced Graphene Oxide ◽  
Reduced Graphene ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
Scanning Electron

In this article, reduced graphene oxide/Ni/multi-walled carbon nanotubes/Fe3O4 filled paste is synthesized with the aim of developing a novel shielding material. To do so, nano-dispersion presenting homogeneous distribution is made by ultrasonic dispersing technology. Next, the effects of nano-absorbent content on the fluidity, mechanical strength, pore structure, resistivity, and absorbing reflectivity of paste are studied. At the end, the microstructure of composite is uncovered by scanning electron microscopy, Fourier transformer infrared, X-ray diffraction images as well as the pore size distribution and absorbing reflectivity are revealed. The results indicate that a small load of reduced graphene oxide and other nano-absorbents can significantly reduce the fluidity and resistivity of paste, but its pore structure is improved so that its mechanical properties are increased. Scanning electron microscopy images indicate that reduced graphene oxide promotes the increasing and thickening of the cement hydration products as well as the growth of a large number of flower-like and compact bulk crystals. Furthermore, the minimum reflectivity of −10.6 dB is obtained in the range of 2–18 GHz while the effective bandwidth of 16 GHz is obtained when reflectivity is less than −5 dB. This research provides a new pathway for the preparation of monolayer cement–based absorber.

scholarly journals Studies of physicochemical properties of graphite oxide and thermally exfoliated/reduced graphene oxide

2015 ◽  
Vol 17 (4) ◽  
pp. 109-114 ◽  
Author(s):  
Sabina Elżbieta Drewniak ◽  
Tadeusz Piotr Pustelny ◽  
Roksana Muzyka ◽  
Agnieszka Plis
Keyword(s):  
Electron Microscopy ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Graphite Oxide ◽  
Force Microscopy ◽  
Atomic Force ◽  
Reduced Graphene ◽  
Elemental Analyses ◽  
Composition Changes ◽  
Scanning Electron

Abstract The aim of the experimental research studies was to determine some electrical properties of graphite oxide and thermally exfoliated/reduced graphene oxide. The authors tried to interpret the obtained physicochemical results. For that purpose, both resistance measurements and investigation studies were carried out in order to characterize the samples. The resistance was measured at various temperatures in the course of composition changes of gas atmospheres (which surround the samples). The studies were also supported by such methods as: scanning electron microscopy (SEM), Raman spectroscopy (RS), atomic force microscopy (AFM) and thermogravimetry (TG). Moreover, during the experiments also the elemental analyses (EA) of the tested samples (graphite oxide and thermally exfoliated/reduced graphene oxide) were performed.

scholarly journals Co2TiO4/Reduced Graphene Oxide Nanohybrids for Electrochemical Sensing Applications

Nanomaterials ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 1611
Author(s):  
Constanza J. Venegas ◽  
Fabiana A. Gutierrez ◽  
Marcos Eguílaz ◽  
José F. Marco ◽  
Nik Reeves-McLaren ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Hydrogen Peroxide ◽  
Scanning Electron Microscopy ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Hybrid Materials ◽  
X Ray ◽  
Reduced Graphene ◽  
Scanning Electron

For the first time, the synthesis, characterization, and analytical application for hydrogen peroxide quantification of the hybrid materials of Co2TiO4 (CTO) and reduced graphene oxide (RGO) is reported, using in situ (CTO/RGO) and ex situ (CTO+RGO) preparations. This synthesis for obtaining nanostructured CTO is based on a one-step hydrothermal synthesis, with new precursors and low temperatures. The morphology, structure, and composition of the synthesized materials were examined using scanning electron microscopy, X-ray diffraction (XRD), neutron powder diffraction (NPD), and X-ray photoelectron spectroscopy (XPS). Rietveld refinements using neutron diffraction data were conducted to determine the cation distributions in CTO. Hybrid materials were also characterized by Brunauer–Emmett–Teller adsorption isotherms, Scanning Electron microscopy, and scanning electrochemical microscopy. From an analytical point of view, we evaluated the electrochemical reduction of hydrogen peroxide on glassy carbon electrodes modified with hybrid materials. The analytical detection of hydrogen peroxide using CTO/RGO showed 11 and 5 times greater sensitivity in the detection of hydrogen peroxide compared with that of pristine CTO and RGO, respectively, and a two-fold increase compared with that of the RGO+CTO modified electrode. These results demonstrate that there is a synergistic effect between CTO and RGO that is more significant when the hybrid is synthetized through in situ methodology.

scholarly journals Eco-Friendly Reduced Graphene Oxide Nanofilter Preparation and Application for Iron Removal

Separations ◽  
2021 ◽  
Vol 8 (5) ◽  
pp. 68
Author(s):  
Pankaj Kumar Jha ◽  
Watsa Khongnakorn ◽  
Chamorn Chawenjkigwanich ◽  
Md Shahariar Chowdhury ◽  
Kuaanan Techato
Keyword(s):  
Contact Angle ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Inductively Coupled Plasma ◽  
Membrane Filter ◽  
Water Flux ◽  
Water Filtration ◽  
Dimethyl Formamide ◽  
Reduced Graphene ◽  
Callistemon Viminalis

In this paper, the green synthesis of reduced graphene oxide (r-GO) nanomaterials using Callistemon viminalis leaf extract as a reducing and stabilizing agent is reported for the first time. The synthesized r-GO nanomaterials were characterized using UV–Vis, XRD, FE-SEM, TEM, and energy dispersive X-ray (EDX) analyses. The nanofilter membrane was prepared by varying the amounts of r-GO nanomaterials in a Polysulfone-N,N-dimethyl formamide (DMF) solution. The nanofilter membrane was characterized by the contact angle, atomic force microscopy (AFM), UV–Vis, and FTIR. The results confirm the formation of r-GO nanomaterials. Higher amounts of r-GO nanomaterials in the membrane show a lower contact angle, thus confirming their hydrophilic nature. Iron water filtration was performed with different amounts of r-GO nanomaterials in the membrane filter, and the water flux was smooth over an increased time period. Inductively Coupled Plasma (ICP) analysis showed a higher percentage of iron rejection (95.77%) when higher amounts (0.10 g) of r-GO nanomaterials were used in a mixed membrane (i.e., sample C). In conclusion, the findings illustrate that Callistemon viminalis mediates the synthesis of r-GO nanomaterials, which is useful in water filtration, and can be incorporated into membrane filters, since it removes iron.

Viscoelastic behavior of suspensions of reduced graphene oxide nanoparticles in epoxy

2021 ◽  
Vol 119 (4) ◽  
pp. 041901
Author(s):  
M. Majidian ◽  
A. Magrez ◽  
L. Forró ◽  
Y. Leterrier
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Viscoelastic Behavior ◽  
Oxide Nanoparticles ◽  
Reduced Graphene

scholarly journals Reduced graphene oxide and inorganic nanoparticles composites – synthesis and characterization

2015 ◽  
Vol 17 (4) ◽  
pp. 95-103 ◽  
Author(s):  
Magdalena Onyszko ◽  
Karolina Urbas ◽  
Malgorzata Aleksandrzak ◽  
Ewa Mijowska
Keyword(s):  
Graphene Oxide ◽  
Metal Oxide ◽  
Reduced Graphene Oxide ◽  
Zirconium Dioxide ◽  
Water Solution ◽  
Metal Oxide Nanoparticles ◽  
Direct Synthesis ◽  
Inorganic Nanoparticles ◽  
Oxide Nanoparticles ◽  
Reduced Graphene

Abstract Graphene – novel 2D material, which possesses variety of fascinating properties, can be considered as a convenient support material for the nanoparticles. In this work various methods of synthesis of reduced graphene oxide with metal or metal oxide nanoparticles will be presented. The hydrothermal approach for deposition of platinum, palladium and zirconium dioxide nanoparticles in ethylene glycol/water solution was applied. Here, platinum/reduced graphene oxide (Pt/RGO), palladium/reduced graphene oxide (Pd/RGO) and zirconium dioxide/reduced graphene oxide (ZrO2/RGO) nanocomposites were prepared. Additionally, manganese dioxide/reduced graphene oxide nanocomposite (MnO2/RGO) was synthesized in an oleic-water interface. The obtained nanocomposites were investigated by transmission electron microscopy (TEM), X-ray diffraction analysis (XRD), Raman spectroscopy and thermogravimetric analysis (TGA). The results shows that GO can be successfully used as a template for direct synthesis of metal or metal oxide nanoparticles on its surface with a homogenous distribution.

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