scholarly journals Structure of Coal-Derived Metal-Supported Few-Layer Graphene Composite Materials Synthesized Using a Microwave-Assisted Catalytic Graphitization Process

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1672
Author(s):  
Faridul Islam ◽  
Arash Tahmasebi ◽  
Rou Wang ◽  
Jianglong Yu
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Bituminous Coal ◽  
Critical Role ◽  
Fabricated Metal ◽  
Catalytic Graphitization ◽  
Microwave Assisted ◽  
Layer Graphene ◽  
Transmission Electron ◽  
Few Layer Graphene

Metal-supported few-layer graphene (FLG) was synthesized via microwave-assisted catalytic graphitization owing to the increasing demand for it and its wide applications. In this study, we quickly converted earth-abundant and low-cost bituminous coal to FLG over Fe catalysts at a temperature of 1300 °C. X-ray diffraction, Raman spectroscopy, transmission electron microscopy, and N2 adsorption–desorption experiments were performed to analyze the fabricated metal-supported FLG. The results indicated that the microwave-irradiation temperature at a set holding-time played a critical role in the synthesis of metal-supported FLG. The highest degree of graphitization and a well-developed pore structure were fabricated at 1300 °C using a S10% Fe catalyst for 20 min. High-resolution transmission electron microscopy analysis confirmed that the metal-supported FLG fabricated via microwave-assisted catalytic graphitization consisted of 3–6 layers of graphene nanosheets. In addition, the 2D band at 2700 cm−1 in the Raman spectrum of the fabricated metal-supported FLG samples were observed, which indicated the presence of few-layer graphene structure. Furthermore, a mechanism was proposed for the microwave-assisted catalytic graphitization of bituminous coal. Here, we developed a cost-effective and environmental friendly metal-supported FLG method using a coal-based carbonaceous material.

Few-Layer Graphene as a Support Film for Transmission Electron Microscopy Imaging of Nanoparticles

2009 ◽  
Vol 1 (12) ◽  
pp. 2886-2892 ◽  
Author(s):  
James R. McBride ◽  
Andrew R. Lupini ◽  
Michael A. Schreuder ◽  
Nathanael J. Smith ◽  
Stephen J. Pennycook ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Microscopy Imaging ◽  
Layer Graphene ◽  
Transmission Electron ◽  
Few Layer Graphene

scholarly journals Isolation and Characterization of Outer Membrane Vesicles of Pectobacterium brasiliense 1692

2021 ◽  
Vol 9 (9) ◽  
pp. 1918
Author(s):  
Silindile Maphosa ◽  
Lucy Novungayo Moleleki
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Outer Membrane ◽  
Critical Role ◽  
Membrane Vesicles ◽  
Outer Membrane Vesicles ◽  
Broad Host Range ◽  
Isolation And Characterization ◽  
Transmission Electron ◽  
Animal Pathogens

Pectobacterium brasiliense (Pbr) 1692 is an aggressive phytopathogen affecting a broad host range of crops and ornamental plants, including potatoes. Previous research on animal pathogens, and a few plant pathogens, revealed that Outer Membrane Vesicles (OMVs) are part of Gram-negative bacteria’s (GNB) adaptive toolkit. For this reason, OMV production and subsequent release from bacteria is a conserved process. Therefore, we hypothesized that OMVs might transport proteins that play a critical role in causing soft rot disease and in the survival and fitness of Pbr1692. Here, we show that the potato pathogen, Pbr1692, releases OMVs of various morphologies in Luria Bertani media at 31 °C. Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) confirmed the production of OMVs by Pbr1692 cells. Transmission Electron Microscopy showed that these exist as chain-, single-, and double-membrane morphologies. Mass spectrometry followed by Gene Ontology, Clusters of Orthologous Groups, Virulence Factor, CAZymes, Antibiotic Resistance Ontology, and Bastion6 T6SE annotations identified 129 OMV-associated proteins with diverse annotated roles, including antibiotic stress response, virulence, and competition. Pbr1692 OMVs contributed to virulence in potato tubers and elicited a hypersensitive response in Nicotiana benthamiana leaves. Furthermore, Pbr1692 OMVs demonstrated antibacterial activity against Dickeya dadantii.

scholarly journals Scanning Transmission Electron Microscopy for Polymer Blends

2017 ◽  
Vol 4 (1) ◽  
pp. 31-36
Author(s):  
Pradeep Singh ◽  
B. R. Venugopal ◽  
Radha Kamalakaran
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Polymer Blends ◽  
Scanning Transmission Electron Microscopy ◽  
Critical Role ◽  
Polymer Materials ◽  
Scanning Transmission Electron ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Butadiene Styrene

Physical properties of the polymer can be altered by mixing one or more polymers together also known as polymer blending. The miscibility of polymers is a key parameter in determining the properties of polymer blend. Conventional transmission electron microscopy (CTEM) plays a critical role in determining the miscibility and morphology of the polymers in blend system. One of the most difficult part in polymer microscopy is the staining by heavy metals to generate contrast in CTEM. RuO4 and OsO4 are commonly used to stain the polymer materials for CTEM imaging. CTEM imaging is difficult to interpret for blends due to lack of clear distinction in contrast. Apart from having difficulty in contrast generation, staining procedures are extremely dangerous as improper handling could severely damage skin, eyes, lungs etc. We have used scanning transmission electron microscopy (STEM) to image polymer blends without any staining processes. In current work, Acrylonitrile Butadiene Styrene (ABS)/Methacrylate Butadiene Styrene (MBS) and Styrene Acrylonitrile (SAN) along with filler additive were dispersed on Polycarbonate (PC) matrix and studied by STEM/HAADF (high angle annular dark field). By using HAADF, contrast was generated through molecular density difference to differentiate components in the blend.

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