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.

Application of external voltage for fouling mitigation from graphene oxide, reduced graphene oxide and molybdenum disulfide functionalized surfaces

2019 ◽  
Vol 6 (3) ◽  
pp. 925-936 ◽  
Author(s):  
Iftaykhairul Alam ◽  
Linda M. Guiney ◽  
Mark C. Hersam ◽  
Indranil Chowdhury
Keyword(s):  
Graphene Oxide ◽  
Molybdenum Disulfide ◽  
Reduced Graphene Oxide ◽  
Water Filtration ◽  
External Voltage ◽  
Fouling Mitigation ◽  
Functionalized Surfaces ◽  
Reduced Graphene

Fouling of surfaces remains one of the largest challenges in the field of water filtration.

scholarly journals The Effects of Hydrophobicity and Textural Properties on Hexamethyldisiloxane Adsorption in Reduced Graphene Oxide Aerogels

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 1130
Author(s):  
Xifeng Hou ◽  
Yanhui Zheng ◽  
Xiaolong Ma ◽  
Yuheng Liu ◽  
Zichuan Ma
Keyword(s):  
Contact Angle ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Hydrothermal Treatment ◽  
Textural Properties ◽  
Treatment Temperature ◽  
Spectroscopic Techniques ◽  
Industrial Grade ◽  
Bed Temperature ◽  
Reduced Graphene

To expand the applications of graphene-based materials to biogas purification, a series of reduced graphene oxide aerogels (rGOAs) were prepared from industrial grade graphene oxide using a simple hydrothermal method. The influences of the hydrothermal preparation temperature on the textural properties, hydrophobicity and physisorption behavior of the rGOAs were investigated using a range of physical and spectroscopic techniques. The results showed that the rGOAs had a macro-porous three-dimensional network structure. Raising the hydrothermal treatment temperature reduced the number of oxygen-containing groups, whereas the specific surface area (SBET), micropore volume (Vmicro) and water contact angle values of the rGOAs all increased. The dynamic adsorption properties of the rGOAs towards hexamethyldisiloxane (L2) increased with increasing hydrothermal treatment temperature and the breakthrough adsorption capacity showed a significant linear association with SBET, Vmicro and contact angle. There was a significant negative association between the breakthrough time and inlet concentration of L2, and the relationship could be reliably predicted with a simple empirical formula. L2 adsorption also increased with decreasing bed temperature. Saturated rGOAs were readily regenerated by a brief heat-treatment at 100 °C. This study has demonstrated the potential of novel rGOA for applications using adsorbents to remove siloxanes from biogas.

scholarly journals General Synthesis of Ultrafine Metal Oxide/Reduced Graphene Oxide Nanocomposites for Ultrahigh-Flux Nanofiltration Membrane

2021 ◽  
Author(s):  
Wanyu Zhang ◽  
Hai Xu ◽  
Fei Xie ◽  
Xiaohua Ma ◽  
Bo Niu ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Metal Oxide ◽  
Reduced Graphene Oxide ◽  
Active Sites ◽  
Metal Oxide Nanoparticles ◽  
Water Flux ◽  
Size Exclusion ◽  
Colloidal Solutions ◽  
Ultrafine Metal ◽  
Reduced Graphene

Abstract Graphene-based membranes have great potential to revolutionize nanofiltration technology, but achieving high solute rejections at high water flux remains extremely challenging. Herein, a family of ultrafine metal oxide/reduced graphene oxide (rGO) nanocomposites are synthesized through a heterogenous nucleation and diffusion-controlled growth process for dye nanofiltration. The synthesis is based on the utilization of oxygen functional groups on GO surface as preferential active sites for heterogeneous nucleation, leading to the formation of sub-3nm size, monodispersing as well as high-density loading of metal oxide nanoparticles. The anchored ultrafine nanoparticles could inhibit the wrinkling of the rGO nanosheet, forming highly stable colloidal solutions for solution-processing fabrication of nanofiltration membranes. By functioning as pillars, the nanoparticles remarkably increase both vertical interlayer spacing and lateral tortuous paths of the rGO membranes, offering an unprecedented water permeability of 225 L m− 2 h− 1 bar − 1 and a high selectivity up to 98% in the size-exclusion separation of methyl blue.

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 coating enhances osteogenic differentiation of human mesenchymal stem cells on Ti surfaces

2021 ◽  
Vol 25 (1) ◽  
Author(s):  
Moon Sung Kang ◽  
Seung Jo Jeong ◽  
Seok Hyun Lee ◽  
Bongju Kim ◽  
Suck Won Hong ◽  
...  
Keyword(s):  
Stem Cells ◽  
Contact Angle ◽  
Mesenchymal Stem Cells ◽  
Graphene Oxide ◽  
Osteogenic Differentiation ◽  
Reduced Graphene Oxide ◽  
Human Mesenchymal Stem Cells ◽  
Alp Activity ◽  
Reduced Graphene ◽  
Graphene Derivatives

Abstract Background Titanium (Ti) has been utilized as hard tissue replacement owing to its superior mechanical and bioinert property, however, lack in tissue compatibility and biofunctionality has limited its clinical use. Reduced graphene oxide (rGO) is one of the graphene derivatives that possess extraordinary biofunctionality and are known to induce osseointegration in vitro and in vivo. In this study, rGO was uniformly coated by meniscus-dragging deposition (MDD) technique to fabricate rGO-Ti substrate for orthopedic and dental implant application. Methods The physicochemical characteristics of rGO-coated Ti (rGO-Ti) substrates were evaluated by atomic force microscopy, water contact angle, and Raman spectroscopy. Furthermore, human mesenchymal stem cells (hMSCs) were cultured on the rGO-Ti substrate, and then their cellular behaviors such as growth and osteogenic differentiation were determined by a cell counting kit-8 assay, alkaline phosphatase (ALP) activity assay, and alizarin red S staining. Results rGO was coated uniformly on Ti substrates by MDD process, which allowed a decrease in the surface roughness and contact angle of Ti substrates. While rGO-Ti substrates significantly increased cell proliferation after 7 days of incubation, they significantly promoted ALP activity and matrix mineralization, which are early and late differentiation markers, respectively. Conclusion It is suggested that rGO-Ti substrates can be effectively utilized as dental and orthopedic bone substitutes since these graphene derivatives have potent effects on stimulating the osteogenic differentiation of hMSCs and showed superior bioactivity and osteogenic potential.

scholarly journals Preparation of a graphene/silver hybrid membrane as a new nanofiltration membrane

RSC Advances ◽  
2017 ◽  
Vol 7 (77) ◽  
pp. 49159-49165 ◽  
Author(s):  
Gui-fei Liu ◽  
Lin-jun Huang ◽  
Yan-xin Wang ◽  
Jian-guo Tang ◽  
Yao Wang ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Composite Membrane ◽  
Reduction Method ◽  
Water Flux ◽  
Thermal Reduction ◽  
Hybrid Membrane ◽  
Nanofiltration Membrane ◽  
Reduced Graphene

In this study, we describe the preparation, characterization, water flux and rejection performance of a composite membrane formed from reduced graphene oxide (RGO) and silver nanoparticles (AgNP) via a rapid thermal reduction method.

Ultra Fast Oil-Water Separation for Different Viscous Oil Using Flourine-Free, Reusable, Superhydrophobic Polyurethane Sponge

2020 ◽  
Vol 20 (3) ◽  
pp. 1540-1553 ◽  
Author(s):  
Jing Ma ◽  
Weihui Zhu ◽  
Patrick Osei Lartey ◽  
Wen Qin
Keyword(s):  
Contact Angle ◽  
Graphene Oxide ◽  
High Temperature ◽  
Reduced Graphene Oxide ◽  
Water Contact ◽  
Water Separation ◽  
Reduced Graphene ◽  
Oil Water Separation ◽  
Polyurethane Sponge ◽  
Oil Water

To exploit new adsorbents for oil-spill cleanup, a superhydrophobic material was fabricated by hightemperature reduced graphene oxide (HRGO) coated on commercial polyurethane (PU) sponge via facile dip-coating process. Compared with chemical reagent reduced graphene oxide, the graphene showed expanded sheets and vast surface area, which ensured the water contact angle of this synthesized sponge reached 150.0±2.5°. In order to break the boundary of poor adhesion of graphene on sponge skeleton, a simple approach of sealed thermal treatment was adopted in our work. And then the high-temperature reduced graphene oxide/polyurethane sponge treated with binary flourine-free organosilanes solution showed superhydrophobicity with high water contact angle (162.4±1.0°). Silanes addition also endowed the resultant sponge with enhanced interfacial adhesion on PU skeleton owing to interconnected structure. The as-prepared sponge displayed excellent adsorption capacity, which was 48–74 times of its own weight for different organic solvents and oils, and no decrease of the adsorption capacity was observed after 20 cycles. Besides, for the very sticky oil, the Joule-heat generated in the sponge by applied voltage could reduce the viscosity of oil. With the assistance of Joule-heat, the silane modified high-temperature reduced graphene oxide/polyurethane sponge achieved effective oil-water separation and greatly speeded up the separation efficiency. Additionally, whether in various temperature or corrosive conditions, the superhydrophobicity of the sponge almost remained stable, which was promising for oil/water treatment.

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