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 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.

One-step hydrothermal treatment to fabricate Bi2WO6-reduced graphene oxide nanocomposites for enhanced visible light photoelectrochemical performance

2017 ◽  
Vol 5 (20) ◽  
pp. 3718-3727 ◽  
Author(s):  
Saibo Chen ◽  
Hao Nan ◽  
Xuan Zhang ◽  
Yuting Yan ◽  
Zhou Zhou ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Visible Light ◽  
Reduced Graphene Oxide ◽  
Hydrothermal Treatment ◽  
Solvothermal Method ◽  
Photoelectrochemical Performance ◽  
Reduced Graphene ◽  
One Step

Bi2WO6 functionalized reduced oxide nanocomposites were prepared by a one-step solvothermal method and their photoelectrochemical performance was greatly improved.

scholarly journals Vitamin C-Assisted Fabrication of Aerogels from Industrial Graphene Oxide for Gaseous Hexamethyldisiloxane Adsorption

2021 ◽  
Vol 11 (18) ◽  
pp. 8486
Author(s):  
Yanhui Zheng ◽  
Xifeng Hou ◽  
Xiaolong Ma ◽  
Zelin Hao ◽  
Zichuan Ma
Keyword(s):  
Contact Angle ◽  
Graphene Oxide ◽  
Vitamin C ◽  
Energy Utilization ◽  
Raw Material ◽  
Raman Spectrometry ◽  
Water Contact ◽  
Industrial Grade ◽  
Bed Temperature ◽  
Hierarchical Porous

Volatile methyl siloxanes (VMSs) as a trace impurity in biogas decreases its energy utilization, and thus need to be removed. In this paper, a one-step hydrothermal reduction was performed to produce three-dimensional reduced graphene oxide aerogels (rGOAs) using industrial-grade graphene oxide (IGGO) as raw material and vitamin C (VC) as a reductant to facilitate the fabrication of rGOAs. The synthesis of rGOAs was a simple, green, and energy-efficient process. The developed rGOAs were characterized using the Brunauer–Emmett–Teller method, Raman spectrometry, scanning electron microscopy, Fourier-transform infrared spectroscopy, X-ray diffraction measurements and contact angle. The results obtained showed that rGOA-1 with a VC/IGGO ratio of 1/1 (m/m) exhibited a hierarchical porous structure and super-hydrophobicity, yielding a high specific surface area (137.9 m2 g−1) and superior water contact angle (143.8°). The breakthrough adsorption capacity of rGOA-1 for hexamethyldisiloxane (L2, a VMS model) was 11 times higher than that of IGGO. Low inlet concentration and bed temperature were considered beneficial for the L2 adsorption. Interestingly, rGOA-1 was less sensitive to water, and it was readily regenerated for reuse by annealing at 80 °C. The rGOAs have been demonstrated to have great potential for the removal of siloxanes from biogas.

scholarly journals Synthesis of Polypyrrole/Reduced Graphene Oxide Hybrids via Hydrothermal Treatment for Energy Storage Applications

Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2273 ◽  
Author(s):  
Adam Moyseowicz ◽  
Krzysztof Pająk ◽  
Katarzyna Gajewska ◽  
Grażyna Gryglewicz
Keyword(s):  
Graphene Oxide ◽  
Chemical Composition ◽  
Electrochemical Properties ◽  
Reduced Graphene Oxide ◽  
Hydrothermal Treatment ◽  
Hybrid Materials ◽  
Electrode Materials ◽  
Conductive Polymer ◽  
Surface Areas ◽  
Reduced Graphene

Herein, we propose hydrothermal treatment as a facile and environmentally friendly approach for the synthesis of polypyrrole/reduced graphene oxide hybrids. A series of self-assembled hybrid materials with different component mass ratios of conductive polymer to graphene oxide was prepared. The morphology, porous structure, chemical composition and electrochemical performance of the synthesized hybrids as electrode materials for supercapacitors were investigated. Nitrogen sorption analysis at 77 K revealed significant changes in the textural development of the synthesized materials, presenting specific surface areas ranging from 25 to 199 m2 g−1. The combination of the pseudocapacitive polypyrrole and robust graphene material resulted in hybrids with excellent electrochemical properties, which achieved specific capacitances as high as 198 F g−1 at a current density of 20 A g−1 and retained up to 92% of their initial capacitance after 3000 charge–discharge cycles. We found that a suitable morphology and chemical composition are key factors that determine the electrochemical properties of polypyrrole/reduced graphene oxide hybrid materials.

A bifunctional NiCo2S4/reduced graphene oxide@polyaniline nanocomposite as a highly-efficient electrode for glucose and rutin detection

2018 ◽  
Vol 42 (12) ◽  
pp. 9398-9409 ◽  
Author(s):  
Yanying Wang ◽  
Ji Zhong ◽  
Fang Ding ◽  
Qingbiao Zhao ◽  
Zhaoyi Zhang ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Hydrothermal Treatment ◽  
Polymerization Process ◽  
Highly Efficient ◽  
Pani Composite ◽  
Reduced Graphene ◽  
Polyaniline Nanocomposite

A novel NiCo2S4/reduced graphene oxide@polyaniline (NiCo2S4/rGO@PANI) composite was synthesized by a facile two-step hydrothermal treatment and calcination, which was coupled with an in situ polymerization process.

scholarly journals Reduced Graphene Oxide/Polymer Monolithic Materials for Selective CO2 Capture

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 936 ◽  
Author(s):  
Nikolaos Politakos ◽  
Iranzu Barbarin ◽  
Tomás Cordero-Lanzac ◽  
Alba Gonzalez ◽  
Ronen Zangi ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Specific Surface ◽  
Reduced Graphene Oxide ◽  
Surface Area ◽  
Functional Groups ◽  
Specific Surface Area ◽  
Co2 Capture ◽  
Textural Properties ◽  
Reduced Graphene ◽  
Hierarchical Porous

Polymer composite materials with hierarchical porous structure have been advancing in many different application fields due to excellent physico-chemical properties. However, their synthesis continues to be a highly energy-demanding and environmentally unfriendly process. This work reports a unique water based synthesis of monolithic 3D reduced graphene oxide (rGO) composite structures reinforced with poly(methyl methacrylate) polymer nanoparticles functionalized with epoxy functional groups. The method is based on reduction-induced self-assembly process performed at mild conditions. The textural properties and the surface chemistry of the monoliths were varied by changing the reaction conditions and quantity of added polymer to the structure. Moreover, the incorporation of the polymer into the structures improves the solvent resistance of the composites due to the formation of crosslinks between the polymer and the rGO. The monolithic composites were evaluated for selective capture of CO2. A balance between the specific surface area and the level of functionalization was found to be critical for obtaining high CO2 capacity and CO2/N2 selectivity. The polymer quantity affects the textural properties, thus lowering its amount the specific surface area and the amount of functional groups are higher. This affects positively the capacity for CO2 capture, thus, the maximum achieved was in the range 3.56–3.85 mmol/g at 1 atm and 25 °C.

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 Synthesis and Characterization of Graphene Oxide and Reduced Graphene Oxide Composites with Inorganic Nanoparticles for Biomedical Applications

Nanomaterials ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1846
Author(s):  
Joanna Jagiełło ◽  
Adrian Chlanda ◽  
Magdalena Baran ◽  
Marcin Gwiazda ◽  
Ludwika Lipińska
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Biomedical Applications ◽  
Active Surface ◽  
Biological Properties ◽  
Inorganic Nanoparticles ◽  
Pristine Graphene ◽  
Spectroscopic Techniques ◽  
Surface Areas ◽  
Reduced Graphene

Graphene oxide (GO) and reduced graphene oxide (RGO), due to their large active surface areas, can serve as a platform for biological molecule adhesion (both organic and inorganic). In this work we described methods of preparing composites consisting of GO and RGO and inorganic nanoparticles of specified biological properties: nanoAg, nanoAu, nanoTiO2 and nanoAg2O. The idea of this work was to introduce effective methods of production of these composites that could be used for future biomedical applications such as antibiotics, tissue regeneration, anticancer therapy, or bioimaging. In order to characterize the pristine graphene materials and resulting composites, we used spectroscopic techniques: XPS and Raman, microscopic techniques: SEM with and AFM, followed by X-Ray diffraction. We obtained volumetric composites of flake graphene and Ag, Au, Ag2O, and TiO2 nanoparticles; moreover, Ag nanoparticles were obtained using three different approaches.

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