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1

The Superior Surface Discharge Capacity of Core-Shell Tinoxide/Multi Walled Carbon Nanotube Nanocomposite Anodes for Li-Ion Batteries

100%

Akbulut H., Alaf M., Gultekin D.

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vol. 125

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issue 2

335-337

EN

In this study, tin/tinoxide/multiwalled carbon nanotube (Sn/SnO_2/MWCNT) nanocomposites were produced as anode materials for Li-ion batteries by a two-step process. Metallic tin was evaporated onto free-standing MWCNT buckypapers having controlled porosity and subsequently rf plasma oxidized in Ar:O_2 (1:1) gas mixture. Besides, Sn/SnO_2 nanocomposites were produced in the same conditions onto stainless steel substrates to make a comparison. X-ray diffraction and scanning electron microscopy were used to determine the structure and morphology of the obtained nanocomposites. The discharge/charge tests, cyclic voltammetry and electrochemical impedance spectroscopy were carried out to characterize the electrochemical properties of these composites. Promising results were obtained in the tin based MWCNT nanocomposites for next-generation micro battery applications because of the high active surface area of the SnO_2/MWCNT core-shell structures.

2

Nanostructure Formation during Amorphous Carbon Films Deposition

100%

Rutkuniene Z., Vigricaite L., Grigonis A.

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vol. 125

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issue 6

1303-1306

EN

Influence of Cu particles for the carbon nanostructures formation during a-C:H films deposition by plasma enhanced chemical vapor deposition method from pure acetylene gas plasma were analyzed in this work. Silicon wafer and Cu target were simultaneously bombarded by Ar^{+} ions for the Cu particles deposition on the silicon before a-C:H films formation. It was obtained that hydrogenated silicon carbide forms on this defected Si/Cu surface during the first stage of carbon film deposition. Structure of a:C-H films and conditions of nanostructures formation depended on substrate temperature and Cu concentration in the film, then deposition time was 300 s.

3

Influence of Carbon Nanoparticles Morphology on Physical Properties of Polymer Composites

100%

Wróblewski G., Słoma M., Janczak D., Młożniak A., Jakubowska M.

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vol. 125

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issue 4

861-863

EN

The paper presents influence of diverse shapes and dimensions of carbon nanostructures on physical properties of polymer composites. Graphene nanoplatelets, carbon nanotubes, graphite nanofibers, and graphite microflakes have been investigated as fillers in polymethacrylate resin. Layers were deposited with printing techniques used in printed electronics technology such as screen printing and spray coating, both elaborated in our earlier works. Different sets of measurements have been performed for obtained layers with particular carbon nanofillers. Thickness and topography have been examined using optical profilometer. Morphology of nanostructures has been observed with scanning electron microscope. Moreover, sheet resistivity and optical transmission in visible wavelength have been measured. Also mechanical properties have been characterized for each polymer composite by conducting fatigue test which consisted of multiple bending cycles.

4

Composition and Microstructure of the Al-Multilayer Graphene Composites Achieved by the Intensive Deformation

100%

Czeppe T., Korznikova E., Ozga P., Wrobel M., Litynska-Dobrzynska L., Korznikova G., Korznikov A., Czaja P., Socha R.

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vol. 126

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issue 4

921-927

EN

The paper presents results of the studies concerning aluminum-graphene composites produced with use of step technique; first mechanical alloying of Al and graphene powders and later intensive deformation by the high pressure torsion. As a result small, thin and round samples of composites, about 10 mm in diameter were achieved. For comparison similar samples not containing graphene were investigated. The X-ray diffraction, transmission electron microscopy, Raman spectroscopy and X-ray photoelectron spectroscopy were applied to study composites structures and analyze graphene content and atomic bonds. The Raman spectroscopy method suggested multilayer graphene, which could also be identified as the defected nano-graphite as a component of the composite structure as well as some small content of the aluminum carbides. The highly dispersed microstructures of aluminum matrices were identified with the transmission electron microscopy, showing difference between the samples produced with the increased number of rotations, leading to the increased deformation realized. This method revealed carbon and aluminum oxides in large amounts which is interpreted as a surface effect. This method suggested also formation of the carbon-metal and carbon-metal- oxygen atomic bonds, which might partially result from formation of the carbides.

5

A New Approach to Synthesis of Free-Standing ZnO/MWCNT Nanocomposites by Vacuum Infiltration

100%

Alaf M., Gultekin D., Akbulut H.

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vol. 125

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issue 2

426-428

EN

In this study, free-standing zincoxide/multiwalled carbon nanotube nanocomposite was synthesized by a multistep technique. Buckypapers having controlled porosity were prepared by vacuum filtration from oxidized multiwalled carbon nanotubes. Zinc acetate dihydrate (ZnAc) (Zn(CH_3COO)_2 ·2H_2O) was used as zinc source and ethanol used as solvent. An appropriate amount of monoethanolamine was added to sol to change acid-base media. The solution was vacuum filtered through buckypaper and annealed at 350C in air. It was found that the zinc oxide grows around the multiwalled carbon nanotubes to form a uniform composite. Morphology of zine oxide/multiwalled carbon nanotube was also studied in detail. Nanocomposite was characterized by X-ray diffraction, scanning electron microscopy, and Raman spectroscopy.

6

Changes in Amorphous Hydrogenated Carbon Films by Ultraviolet and Infrared Laser Irradiation

100%

Vinciūnaitė V., Grigonis A., Medvid A., Zabels R.

Acta Physica Polonica A

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2013

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vol. 123

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issue 5

874-876

EN

Amorphous hydrogenated carbon films were formed on the Si (100) wafers by a direct-ion beam deposition method from pure acetylene and acetylene-hydrogen gas mixtures. The films were irradiated with a nanosecond Nd:YAG laser working at the first harmonics (λ_1=1064 nm), the fourth harmonics (λ_4=266 nm) or with a Nd:YVO_4 laser working at the third harmonic (λ_3=355 nm). The films were studied by the Raman scattering, micro-Fourier transform infrared and Fourier transform infrared spectroscopies, null-ellipsometry, optical and scanning electron microscope, and Vickers hardness method. Irradiation by the wavelength λ_1=1064 nm leads to graphitization and formation of the silicon carbide, because of the silicon substrate decomposition. The samples were strongly modified after the irradiation by λ_3=355 nm - the thickness of the films decreased, and silicon carbide was formed. It was observed that nano-structured materials (e.g. carbon nano-onions, nc-diamond) were formed after the irradiation by λ_4=266 nm.

7

Different Wavelength Laser Irradiation of Amorphous Carbon

100%

Grigonis A., Rutkuniene Z., Vinciunaite V.

Acta Physica Polonica A

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2011

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vol. 120

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issue 1

26-29

EN

Coherent laser irradiation of amorphous carbon films formed on Si substrates by ion beam deposition from pure acetylene and acetylene/hydrogen gas mixture is analyzed in this work. The films were irradiated with nanosecond YAG:Nd laser (Ekspla NL301G) at the first (1064 nm, 6 ns), the second (532 nm, 4.2 ns) and the third (355 nm, 28 ns) harmonic by scanning or repeating (10 pulses to one point) regime. Irradiation by the first laser harmonic leads to a minor increase of graphite phase content and shows SiC formation. Formation of carbides was observed at the second harmonic irradiation when irradiation intensity is low (< 10 MW/cm^2). Graphitization became more intensive when power density of irradiation increased and the films transformed to the glass carbon and nano/micro crystallite compound at intensive ablation regime ( ≈ 24 MW/cm^2). Early ablation starts at irradiation by the third laser harmonic with the intensity of ≈ 8 MW/cm^2 with an increase of Si substrate roughness. Swelling of films was obtained when the sample was irradiated at the third harmonic with 1 MW/cm^2.

8

Composites for Bone Surgery Based on Micro- and Nanocarbons

88%

Stodolak E., Fraczek-Szczypta A., Blazewicz M., Blazewicz S.

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issue 3

450-456

EN

In this work capabilities of polymer composites modified with carbon materials for application in the bone surgery were compared. The composite materials were produced from synthetic polymer PTFE-PVDF-PP modified with a carbon phase such as: short carbon fibres, carbon nanotubes and carbon fabrics. Determination of mechanical properties of the composite materials indicated that the carbon phase improves strength and Young's modulus of the composite. Moreover, the mechanical parameters can be controlled by the form and amount of the carbon phase introduced into the polymer matrix. Both the fibres and the carbon nanotubes influenced wettability and surface energy of the composites. Also topography of the materials surface was altered, and its roughness was optimal for bone cells (profilometry). Osteoblasts contacted with the polymer-carbon composites showed increased viability comparing with the ones contacting with the pure polymer foil (viability, and cells proliferation: MTT method, concentration of bone protein: viniculine and β-actine). Results of the investigations indicated that the composite materials containing carbon phases are potential materials for repairing of bone tissue damages.

Refine search results

The Superior Surface Discharge Capacity of Core-Shell Tinoxide/Multi Walled Carbon Nanotube Nanocomposite Anodes for Li-Ion Batteries

Nanostructure Formation during Amorphous Carbon Films Deposition

Influence of Carbon Nanoparticles Morphology on Physical Properties of Polymer Composites

Composition and Microstructure of the Al-Multilayer Graphene Composites Achieved by the Intensive Deformation

A New Approach to Synthesis of Free-Standing ZnO/MWCNT Nanocomposites by Vacuum Infiltration

Changes in Amorphous Hydrogenated Carbon Films by Ultraviolet and Infrared Laser Irradiation

Different Wavelength Laser Irradiation of Amorphous Carbon

Composites for Bone Surgery Based on Micro- and Nanocarbons