scholarly journals A facile and viable approach to fabricate polyamide membranes functionalized with graphene oxide nanosheets

RSC Advances ◽  
2017 ◽  
Vol 7 (84) ◽  
pp. 53463-53471 ◽  
Author(s):  
Ruizhi Pang ◽  
Kaisong Zhang
Keyword(s):  
Graphene Oxide ◽  
Functional Groups ◽  
Acid Chloride ◽  
Primary Amine ◽  
Covalent Binding ◽  
Graphene Oxide Nanosheets ◽  
Ro Membrane ◽  
Viable Approach ◽  
Polyamide Membranes

The covalent binding of GO nanosheets to a PA RO membrane was successfully achieved by reacting the primary amine functional groups of aminated GO (AGO) nanosheets with the unreacted acid chloride groups of the nascent PA membrane.

Synthesis of Graphene Oxide Nanosheets via Modified Hummers’ Method and Its Physicochemical Properties

2015 ◽  
Vol 74 (1) ◽  
Author(s):  
Mohamad Fahrul Radzi Hanifah ◽  
Juhana Jaafar ◽  
Madzlan Aziz ◽  
Ahmad Fauzi Ismail ◽  
Mukhlis A. Rahman ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Physicochemical Properties ◽  
Functional Groups ◽  
Interlayer Spacing ◽  
Graphene Oxide Nanosheets ◽  
Hummers Method ◽  
Exfoliated Graphene ◽  
Transmission Electron ◽  
Direct Methanol ◽  
Modified Hummers Method

The efficient synthesis of exfoliated graphene oxide nanosheets (GO) via modified Hummers’ method was successfully carried out. The physicochemical properties of GO were determined by Fourier transform infrared spectroscopy (FTIR), UV-visible spectrophotometry (UV-vis), x-ray diffraction analysis (XRD), Raman spectroscopy, and transmission electron microscopy (TEM). The graphite was fully oxidized by strong oxidizing agent caused the oxygen-containing functional groups such as C-O-C, C=O, and COOH were introduced into the graphite layers as analyzed by Raman and FTIR.  XRD pattern of GO showed 2θ of 12.0o with interlayer spacing ~ 7.37A which describe non uniform crystal structure with the addition of oxygen containing functional groups. UV-vis spectrum of GO exhibit maximum absorption peak at ~ 234 nm corresponding to the aromatic C=C bond with π-π* transition. The morphology of GO was observed to have flake-like shape and less transparent layers by TEM. The properties of synthesized GO suggest high potential in producing the high quality of graphene which is can be applied as the electrocatalyst support for direct methanol fuel cell application.              

Immobilisation of acid pectinase on graphene oxide nanosheets

2014 ◽  
Vol 68 (6) ◽  
Author(s):  
Yang Liu ◽  
Qiang Li ◽  
Yuan-Yuan Feng ◽  
Geng-Sheng Ji ◽  
Tian-Cheng Li ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Functional Groups ◽  
Recent Progress ◽  
Catalytic Efficiency ◽  
Cross Linking ◽  
Carboxyl Group ◽  
Large Specific Surface Area ◽  
Graphene Oxide Nanosheets ◽  
Amino Groups ◽  
Acidic Conditions

AbstractRecent progress in nanotechnology has prompted research interest in immobilised enzymes on graphene oxide (GO) nanosheets for their large specific surface area and abundant functional groups. In the present work, acid pectinase was immobilised on the GO via the cross-linking of amino groups on pectinase and functional groups (e.g. carboxyl group) on the GO surface. Acid pectinase was effectively immobilised on the support and high loading densities were obtained (2400 mg per g of support). In addition, the immobilised enzyme achieved a better catalytic efficiency (K cat/K m) than its free counterpart; 3.7 mg−1 min−1 mL for immobilised pectinase, 3.5 mg−1 min−1 mL for free pectinase. Under acidic conditions, pectinase immobilised on GO will be agglomerated, but the addition of surfactant PEG 6000 could solve the problem and afford higher catalytic activity and catalytic efficiency.

Tuning the oxygen functional groups in graphene oxide nanosheets by optimizing the oxidation time

2021 ◽  
Vol 131 ◽  
pp. 114727
Author(s):  
Nuor Sariyan Suhaimin ◽  
Mohamad Fahrul Radzi Hanifah ◽  
Jashiela wani Jusin ◽  
Juhana Jaafar ◽  
Madzlan Aziz ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Functional Groups ◽  
Oxidation Time ◽  
Graphene Oxide Nanosheets ◽  
Oxygen Functional Groups

Hybrid two-dimensional nickel oxide-reduced graphene oxide nanosheets for supercapacitor electrodes

2021 ◽  
Vol 164 ◽  
pp. 105979
Author(s):  
Xin Gao ◽  
Hengwei Zhang ◽  
Erjun Guo ◽  
Fei Yao ◽  
Zengze Wang ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Nickel Oxide ◽  
Reduced Graphene Oxide ◽  
Two Dimensional ◽  
Graphene Oxide Nanosheets ◽  
Reduced Graphene

scholarly journals Mechanical Properties of Graphene Oxide Coupled by Multi-Physical Field: Grain Boundaries and Functional Groups

Crystals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 62
Author(s):  
Xu Xu ◽  
Zeping Zhang ◽  
Wenjuan Yao
Keyword(s):  
Mechanical Properties ◽  
Graphene Oxide ◽  
Grain Boundaries ◽  
Functional Groups ◽  
Oxygen Content ◽  
Tensile Fracture ◽  
Hydroxyl Groups ◽  
Molecular Configuration ◽  
Spatial Design ◽  
Out Of Plane

Graphene and graphene oxide (GO) usually have grain boundaries (GBs) in the process of synthesis and preparation. Here, we “attach” GBs into GO, a new molecular configuration i.e., polycrystalline graphene oxide (PGO) is proposed. This paper aims to provide an insight into the stability and mechanical properties of PGO by using the molecular dynamics method. For this purpose, the “bottom-up” multi-structure-spatial design performance of PGO and the physical mechanism associated with the spatial structure in mixed dimensions (combination of sp2 and sp3) were studied. Also, the effect of defect coupling (GBs and functional groups) on the mechanical properties was revealed. Our results demonstrate that the existence of the GBs reduces the mechanical properties of PGO and show an “induction” role during the tensile fracture process. The presence of functional groups converts in-plane sp2 carbon atoms into out-of-plane sp3 hybrid carbons, causing uneven stress distribution. Moreover, the mechanical characteristics of PGO are very sensitive to the oxygen content of functional groups, which decrease with the increase of oxygen content. The weakening degree of epoxy groups is slightly greater than that of hydroxyl groups. Finally, we find that the mechanical properties of PGO will fall to the lowest values due to the defect coupling amplification mechanism when the functional groups are distributed at GBs.

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