Effect of fullerene C60 thermal and tribomechanical loading on Raman signals

Dorner-Reisel, Annett; Ritter, Uwe; Moje, Jens; Freiberger, Emma; Scharff, P.

doi:10.1016/j.diamond.2022.109036

“…Nevertheless, signal deconvolution revealed lines around ~1403 cm −1 , ~1469 cm −1 , and ~1549 cm −1 , characteristic of fullerene dimers and 2D polymeric networks. For instance, the presence of Ag(2) serves as an excellent indicator of C 60 polymerization [28]. Additionally, the spectrum exhibits the D-line, originated by the breathing mode of defective sp2-hybridised aromatic C-C rings around ~1364 cm −1 .…”

Section: Resultsmentioning

confidence: 99%

Enhancing the Microhardness of Coatings Produced by Cold Gas Dynamic Spraying through Multi-Reinforcement with Aluminum Powders Containing Fullerenes and Aluminum Nitride

Aborkin,

Babin,

Belyaev

et al. 2023

JMMP

0

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Coatings with high hardness were successfully obtained using low-pressure cold spray (LPCS) technology from nanocrystalline powders based on the aluminum alloy AlMg6, which were multi-reinforced with 0.3 wt.% fullerenes and 10–50 wt.% AlN. The powders were synthesized through a two-stage high-energy ball milling process, resulting in a complex mechanical mixture consisting of agglomerates and micro-sized ceramic particles of AlN. The agglomerates comprise particles of the nanocomposite material AlMg6/C60 with embedded and surface-located, micro-sized ceramic particles of AlN. Scanning electron microscopy and EDS analyses demonstrated a uniform distribution of reinforcing particles throughout the coating volume. An X-ray diffraction (XRD) analysis of the coatings revealed a change in the predominant orientation of matrix alloy grains to a more chaotic state during deformation over the course of cold gas dynamic spraying. A quantitative determination of AlN content in the coating was achieved through the processing of XRD data using the reference intensity ratio (RIR) method. It was found that the proportion of transferred ceramic particles from the multi-reinforced powder to the coating did not exceed ~65%. Experimental evidence indicated that LPCS processing of mono-reinforced nanocrystalline powder composite AlMg6/C60 practically did not lead to the formation of a coating on the substrate and was limited to a monolayer with a thickness of ~10 µm. The microhardness of the monolayer coating obtained from the deposition of AlMg6/C60 powder was 181 ± 12 HV. Additionally, the introduction of 10 to 50 wt.% AlN into the powder mixture contributed to the enhancement of growth efficiency and an increase in coating microhardness by ~1.4–1.7 times. The obtained results demonstrate that the utilization of agglomerated multi-reinforced powders for cold gas dynamic spraying can be an effective strategy for producing coatings and bulk materials based on aluminum and its alloys with high microhardness.

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Curvature‐Induced Electron Spin Catalysis with Carbon Spheres

Qiao,

Cao,

Wang

et al. 2024

Angewandte Chemie

0

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Here, we report curvature‐induced electron spin catalysis by using solid carbon spheres as catalysts, which were synthesized using positive curvature molecular hexabromocyclopentadiene as a precursor molecule, following a radical coupling mechanism. The curvature spin of carbon is regarded as an overlapping state of σ‐ and π‐radical, which is identified by the inverse Laplace transform of pulse‐electron paramagnetic resonance. The growth mechanism of carbon spheres abiding by Kroto's model, is supported by the density functional theory study of thermodynamics and kinetics calculations. The solid carbon spheres present excellent catalytic behaviour of oxidation coupling of amines to form corresponding imines with the conversion of >99 %, selectivity of 98.7 %, and yield of 97.7 %, which is attributed to the predominantly curvature‐induced electron spin catalysis of carbon, supported by the calculation of oxygen adsorption energy. This work proposes a view of curvature‐induced spin catalysis of carbon, which opens up a research direction for curvature‐induced electron spin catalysis.

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Curvature‐Induced Electron Spin Catalysis with Carbon Spheres

Qiao,

Cao,

Wang

et al. 2024

Angew Chem Int Ed

0

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Here, we report curvature‐induced electron spin catalysis by using solid carbon spheres as catalysts, which were synthesized using positive curvature molecular hexabromocyclopentadiene as a precursor molecule, following a radical coupling mechanism. The curvature spin of carbon is regarded as an overlapping state of σ‐ and π‐radical, which is identified by the inverse Laplace transform of pulse‐electron paramagnetic resonance. The growth mechanism of carbon spheres abiding by Kroto's model, is supported by the density functional theory study of thermodynamics and kinetics calculations. The solid carbon spheres present excellent catalytic behaviour of oxidation coupling of amines to form corresponding imines with the conversion of >99 %, selectivity of 98.7 %, and yield of 97.7 %, which is attributed to the predominantly curvature‐induced electron spin catalysis of carbon, supported by the calculation of oxygen adsorption energy. This work proposes a view of curvature‐induced spin catalysis of carbon, which opens up a research direction for curvature‐induced electron spin catalysis.

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Effect of fullerene C60 thermal and tribomechanical loading on Raman signals

Cited by 12 publications

References 49 publications

Enhancing the Microhardness of Coatings Produced by Cold Gas Dynamic Spraying through Multi-Reinforcement with Aluminum Powders Containing Fullerenes and Aluminum Nitride

Enhancing the Microhardness of Coatings Produced by Cold Gas Dynamic Spraying through Multi-Reinforcement with Aluminum Powders Containing Fullerenes and Aluminum Nitride

Curvature‐Induced Electron Spin Catalysis with Carbon Spheres

Curvature‐Induced Electron Spin Catalysis with Carbon Spheres

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