scholarly journals FEW-LAYER GRAPHENE PARTICLES BASED ON THERMALLY EXPANDED COINTERCALATE OF GRAPHITE NITRATE WITH ACETIC AND FORMIC ACIDS

2020 ◽  
pp. 580-590
Author(s):  
Алина Александровна Давыдова ◽  
Елена Владимировна Ракша ◽  
Оксана Николаевна Осколкова ◽  
Виктория Валерьевна Гнатовская ◽  
Петр Владимирович Сухов ◽  
...  
Keyword(s):  
Structural Characteristics ◽  
Intercalation Compound ◽  
Expanded Graphite ◽  
Thermally Expanded Graphite ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Graphite Nitrate ◽  
Graphene Nanoparticles ◽  
Few Layer Graphene ◽  
Acetic Acids

Путем расслоения терморасширенного графита в этиловом и трет-бутиловом спиртах под действием ультразвука получены дисперсии малослойных графеновых наночастиц. Исходный терморасширенный графит получен термической обработкой в ударном режиме нагрева тройного соединения соинтеркалирования нитрата графита с уксусной и муравьиной кислотами. Проведено исследование структурных характеристик соинтеркалата нитрата графита и терморасширенного графита методом рентгенофазового анализа. Микроструктура и морфология полученных графеновых частиц исследованы методом просвечивающей электронной микроскопии. Dispersions of graphene nanoparticles were obtained by liquid phase exfoliation of thermally expanded graphite in ethanol as well as tert-butanol via sonication. Initial thermally expanded graphite was obtained by heat treatment in the shock mode of ternary graphite nitrate intercalation compound with formic and acetic acids. Investigation of the graphite nitrate intercalation compound and thermally expanded graphite structural characteristics by X-ray diffraction analysis has been carried out. The microstructure and morphology of the obtained graphene particles were studied by transmission electron microscopy.

scholarly journals CARBON NANOPARTICLES BASED ON THERMALLY EXPANDED GRAPHITE: EFFECT OF THE TEG OBTAINING ROUTE ON THE PARTICLES MORPHOLOGY

2021 ◽  
pp. 777-787
Author(s):  
Елена Владимировна Ракша ◽  
Валентина Александровна Глазунова ◽  
Оксана Николаевна Осколкова ◽  
Петр Владимирович Сухов ◽  
Галина Кузьминична Волкова ◽  
...  
Keyword(s):  
Carbon Nanoparticles ◽  
Expanded Graphite ◽  
Thermally Expanded Graphite ◽  
X Ray Diffraction ◽  
X Ray ◽  
Carbon Particles ◽  
Tert Butanol ◽  
Transmission Electron ◽  
Graphite Nitrate ◽  
Lower Temperature

В работе представлены результаты исследования морфологии углеродных наночастиц, образующихся при жидкофазном расслоении терморасширенного графита в трет-бутаноле. Используемый в работе терморасширенный графит получен путем термического расширения соинтеркалата нитрата графита с уксусной и муравьиной кислотами в режиме термоудара при 500°С и 900 °С. Исходный соинтеркалант по данным рентгенофазового анализа представляет собой смесь соединений II-й и IV-й стадий интеркалирования. Методом просвечивающей электронной микроскопии установлено, что дисперсии углеродных наночастиц, образующиеся при расслоении терморасширенного графита в трет-бутаноле под действием ультразвука, содержат в основном малослойные графены, планарные размеры которых достигают 8 мкм. Обсуждается влияние условий получения терморасширенного графита на морфологию образующихся углеродных наночастиц. Дисперсии на основе терморасширенного графита, полученного при более низкой температуре, помимо малослойных графенов содержат также значительное количество аморфных углеродных частиц с планарными размерами до 100 нм. The paper presents the investigation results of the morphology of carbon nanoparticles formed during liquid-phase exfoliation of thermally expanded graphite in tert-butanol. The thermally expanded graphite used in this work was obtained by thermal expansion of graphite nitrate with acetic and formic acids in the thermal shock mode at 500 °C and 900 °C. Initial cointercalate was shown by powder X-ray diffraction analysis to be the mixture of the II and the IV stage intercalation compounds. It has been established by transmission electron microscopy that dispersions of carbon nanoparticles formed during the exfoliation of thermally expanded graphite in tert-butanol via sonication contain mainly few-layer graphenes, the planar dimensions of which reach 8 pm. The influence of the conditions for thermally expanded graphite obtaining on the morphology of resulting carbon nanoparticles is discussed. Dispersions based on thermally expanded graphite obtained at a lower temperature, in addition to few-layer graphenes, also contain a significant amount of amorphous carbon particles with planar sizes up to 100 nm.

A High Resolution Study of G.P. Zones in Aluminum - 4.2 at % Silver

1982 ◽  
Vol 40 ◽  
pp. 722-723 ◽  
Author(s):  
R. Gronsky
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Computer Simulations ◽  
Structural Characteristics ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Resolution Study

The phenomenon of clustering in Al-Ag alloys has been extensively studied since the early work of Guinierl, wherein the pre-precipitation state was characterized as an assembly of spherical, ordered, silver-rich G.P. zones. Subsequent x-ray and TEM investigations yielded results in general agreement with this model. However, serious discrepancies were later revealed by the detailed x-ray diffraction - based computer simulations of Gragg and Cohen, i.e., the silver-rich clusters were instead octahedral in shape and fully disordered, atleast below 170°C. The object of the present investigation is to examine directly the structural characteristics of G.P. zones in Al-Ag by high resolution transmission electron microscopy.

Formation of Graphite Encapsulated Nickel Nanoparticles by Ball Milling and Annealing of Expanded Graphite with Nickel

2011 ◽  
Vol 80-81 ◽  
pp. 217-220 ◽  
Author(s):  
Xue Qing Yue ◽  
Hai Jun Fu ◽  
Da Jun Li
Keyword(s):  
Electron Microscope ◽  
Ball Milling ◽  
Transmission Electron Microscope ◽  
Nickel Nanoparticles ◽  
Size Range ◽  
Expanded Graphite ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nickel Powders ◽  
Transmission Electron

Graphite encapsulated nickel nanoparticles were prepared by ball milling andsubsequently annealing a mixture of expanded graphite with nickel powders. The products were characterized by transmission electron microscope and X-ray diffraction. The formation mechanism of the products was discussed. Results show that the products have a size range of 20-150 nm. The graphite and nickel in the products all exhibit a high crystallinity.

Carbon Nanotube Templated Growth of the Nano-Crystalline NaY Zeolite

2011 ◽  
Vol 194-196 ◽  
pp. 594-597
Author(s):  
Ke Tang ◽  
Xin Hong ◽  
Jin Gang Qi
Keyword(s):  
Structural Characteristics ◽  
Internal Diameter ◽  
X Ray Diffraction ◽  
Nay Zeolite ◽  
Nano Crystalline ◽  
Transmission Electron ◽  
Ir Transmission ◽  
Ft Ir ◽  
Nay Zeolites ◽  
Nanosized Zeolites

FAU-type(NaY) zeolites nanocrystals have been synthesized through crystallization of gel in mesoporous system of carbon nanotubes(CNTS) with a internal diameter of 20~30 nm. Investigation by using X-ray diffraction (XRD), Fourier transform infrared (FT-IR), transmission electron microscope (TEM) shows that the nanocrystals possess the typical nanosized zeolites structural characteristics which is different from those of microsized zeolites.

scholarly journals Perovskite CsPbBr3 Quantum Dots Prepared Using Discarded Lead–Acid Battery Recycled Waste

Energies ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 1117 ◽  
Author(s):  
Lung-Chien Chen ◽  
Ching-Ho Tien ◽  
Sin-Liang Ou ◽  
Kun-Yi Lee ◽  
Jianjun Tian ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Structural Characteristics ◽  
Film Surface ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Storage Batteries ◽  
Recycled Waste ◽  
Cspbbr3 Quantum Dots ◽  
Very High ◽  
Lead Acid

Perovskite CsPbBr3 quantum dot (CsPbBr3-QD) recovery was performed using lead scrap from lead storage batteries. The perovskite CsPbBr3-QD characteristics were analyzed using different PbO/recycled PbO2 ratios. Scanning electron microscopy (SEM) was used to observe the film surface morphology and cross-section. High-resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD) were used to observe the perovskite CsPbBr3-QDs’ structural characteristics. A photoluminescence (PL) measurement system was used to analyze the optical properties. The results show that lead scrap from lead–acid batteries as a material for perovskite CsPbBr3-QD production can be successfully synthesized. This saves material and also proves that recycling is valuable. The proposed approach is helpful for future material shortages and materials not easily accessible. Although the efficiency is not very high, this process will be purified using recycled lead in the future to achieve higher quantum yield.

scholarly journals Protein-assisted scalable mechanochemical exfoliation of few-layer biocompatible graphene nanosheets

2021 ◽  
Vol 8 (3) ◽  
Author(s):  
Deepak-George Thomas ◽  
Steven De-Alwis ◽  
Shalabh Gupta ◽  
Vitalij K. Pecharsky ◽  
Deyny Mendivelso-Perez ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Graphene Nanosheets ◽  
Cost Effective ◽  
X Ray Diffraction ◽  
Cytotoxic Effects ◽  
Graphene Layers ◽  
Exfoliated Graphene ◽  
Transmission Electron ◽  
Few Layer Graphene

A facile method to produce few-layer graphene (FLG) nanosheets is developed using protein-assisted mechanical exfoliation. The predominant shear forces that are generated in a planetary ball mill facilitate the exfoliation of graphene layers from graphite flakes. The process employs a commonly known protein, bovine serum albumin (BSA), which not only acts as an effective exfoliation agent but also provides stability by preventing restacking of the graphene layers. The latter is demonstrated by the excellent long-term dispersibility of exfoliated graphene in an aqueous BSA solution, which exemplifies a common biological medium. The development of such potentially scalable and toxin-free methods is critical for producing cost-effective biocompatible graphene, enabling numerous possible biomedical and biological applications. A methodical study was performed to identify the effect of time and varying concentrations of BSA towards graphene exfoliation. The fabricated product has been characterized using Raman spectroscopy, powder X-ray diffraction, transmission electron microscopy and scanning electron microscopy. The BSA-FLG dispersion was then placed in media containing Astrocyte cells to check for cytotoxicity. It was found that lower concentrations of BSA-FLG dispersion had only minute cytotoxic effects on the Astrocyte cells.

One-step preparation and characterization of core-shell SiO2/Ag composite spheres by pulse plating

2017 ◽  
Vol 24 (3) ◽  
pp. 423-427 ◽  
Author(s):  
Li Xiong ◽  
Xiangping Huang ◽  
Ya Liu ◽  
Liqing Pan
Keyword(s):  
Structural Characteristics ◽  
Pulse Plating ◽  
Core Shell ◽  
X Ray Diffraction ◽  
Simple Method ◽  
Transmission Electron ◽  
Surface Enhanced Raman ◽  
One Step ◽  
Enhanced Raman Scattering ◽  
20 Nm

AbstractA simple method of one-step pulse plating was used in the fabrication of core-shell SiO2/Ag composite spheres. Structural characteristics and morphologies of the prepared SiO2/Ag composite spheres are characterized by means of X-ray diffraction, scanning electron microscope, and transmission electron microscopy. The Ag shell is uniformly coated on the surface of SiO2 spheres with the thickness of about 20 nm. Photoluminescence (PL) spectrum has revealed that PL of the core-shell samples is much stronger than that of bare SiO2 spheres. Raman spectrometer measurements show that the SiO2/Ag composite spheres have excellent surface-enhanced Raman scattering performance. In addition, the current-voltage characteristic of SiO2/Ag composite spheres has improved at the same time.

Structural Evolution of Natural Flake Graphite during Intercalation and Exfoliation

2014 ◽  
Vol 552 ◽  
pp. 328-330
Author(s):  
Zhi Guo Liu
Keyword(s):  
Intercalation Compound ◽  
Structural Evolution ◽  
Expanded Graphite ◽  
Expandable Graphite ◽  
Flake Graphite ◽  
Graphite Intercalation Compound ◽  
X Ray Diffraction ◽  
Natural Graphite ◽  
X Ray ◽  
Graphite Intercalation

In order to investigate the structural evolution of natural flake graphite during intercalation and exfoliation, natural graphite flakes were treated by intercalating, water-washing, drying and expanding. The corresponding products, graphite intercalation compound (GIC), residue GIC (expandable graphite) and expanded graphite were characterized by X-ray diffraction (XRD). The results can provide reference for the research in this field.

Microstructure and Anti-Friction Effect of Ball-Milled Expanded Graphite

2013 ◽  
Vol 704 ◽  
pp. 110-113
Author(s):  
Hong Zhang
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Ball Milling ◽  
Expanded Graphite ◽  
High Energy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Friction Effect ◽  
Air Atmosphere ◽  
Transmission Electron

Expanded graphite (EG) was ball-milled in a high-energy mill (planetary-type) under an air atmosphere. The products were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The anti-friction effect of milled EG used as lubricating additive was investigated. After ball-milling, the relatively ordered graphene planes of original EG become deformed, and the d002 spacing becomes broadened. The milled EG used as lubricating additive have an anti-friction effect, and the effect is more marked than that of original EG.

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