Mineral Nanotechnology in Circular Economy

Nobre, Augusto Gonçalves; Martínez, José Armando Espinosa; Florêncio, Odila

doi:10.1007/978-3-030-75680-2_26

Cited by 9 publications

(3 citation statements)

References 12 publications

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“…Graphene, a two-dimensional structure composed of a single layer of carbon atoms arranged in a hexagonal configuration, has garnered considerable interest in both the scientific community and industry, thanks to its remarkable properties (Nobre et al, 2021). The discovery of graphene through the technique of mechanical exfoliation and the subsequent revelation of its properties earned the Nobel Prize in Physics in 2010 for its discoverers (Geim & Novoselov, 2009).…”

Section: Introductionmentioning

confidence: 99%

Status quo of graphene geology in Brazil: mineralogical, petrological and materials science contributions

Stochero,

Nobre

2024

Univers. J. Carbon Res.

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This study investigates the current status of graphene geology in Brazil, highlighting its mineralogical, petrological, and materials science contributions. Three approaches are presented: (I) the natural production of graphene from graphite nanoplates in sheared rocks, (II) the geological simulation under laboratory conditions, and (III) the evolution of electrical resistance in geological formations containing graphite and talc. All reviewed studies underscore the efficacy of graphene production in particular geological contexts, demonstrating its efficient formation within shear zones. The results indicate that graphene stabilises in talc and exhibits improvement in electrical conductivity under specific thermodynamic geological conditions, suggesting abundant natural sources that are economically viable and possess industrial applications. A comparative analysis shows that, although natural graphite nanoplates are thicker than graphene, they still qualify as nanomaterials and demonstrate promising technological potential. The research contributes to understanding the natural formation of graphene and highlights its practical applications in the Fourth and Fifth Industrial Revolution.

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Section: Introductionmentioning

confidence: 99%

Status quo of graphene geology in Brazil: mineralogical, petrological and materials science contributions

Stochero,

Nobre

2024

Univers. J. Carbon Res.

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“…A new way of obtaining graphene and other 2D substances via top-down techniques is the extraction from mineral deposits [28]. There are tectono-structural contexts that allow graphite-bearing rocks to be sheared, forming graphite nanoplatelets and graphene [29].…”

Section: Introductionmentioning

confidence: 99%

Electrical Resistance Evolution of Graphite and Talc Geological Heterostructures under Progressive Metamorphism

Nobre,

de Andrade,

Salazar-Naranjo

et al. 2023

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The electrical properties of isolated graphene established precedents for studies of electrical superconducting materials at room temperature. After the discovery of stabilized graphene and graphite nanoplatelets in a geological context, the interest in characterizing the properties of these minerals arose. This work evaluates the electrical resistance evolution of mineral graphite and talc heterostructures under progressive metamorphism simulated in the laboratory. The experiments were conducted on an end-loaded piston-cylinder apparatus. This equipment allows for the application of equal pressure in all sample directions (lithostatic pressure) and heating, simulating geological phenomena. The behavior of two sets of mineral samples were compared: graphite and talc in billets and powder. Samples in billets were submitted to treatments at 400 °C and 4 kbar; 400 °C and 6 kbar; and 700 °C and 9 kbar. The powder samples were subjected to 700 °C and 9 kbar, with two ways of disposing the mineral powders (mixed and in adjacent contact) beyond 900 °C and 9 kbar (in adjacent contact). The results show that the samples in billets had lower electrical resistance when compared to the powder samples. The lowest electrical resistance was observed in the sample treated at 400 °C and 6 kbar, conditions that are consistent with metamorphic mineral assemblage observed in the field. Powdered samples showed better cleavage efficiency during the experiment, resulting in thinner flakes and even graphene, as pointed out by Raman spectroscopy. However, these flakes were not communicating, which resulted in high electrical resistance, due to the need for an electrical current to pass through the talc, resulting in a Joule effect. The maximum electrical resistance obtained in the experiment was obtained in the sample submitted to 900 °C, in which talc decomposed into other mineral phases that were even more electrically insulating. This work demonstrates that electrical resistance prospecting can be an efficient tool to identify potential target rocks with preserved mineral nanometric heterostructures that can form an important raw material for the nanotechnology industry.

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“…Mineral nanotechnology is an emerging area between Geology and Materials Sciences aiming for (i) increasing the quality of mineral supplies to produce nanomaterials and (ii) the direct exploration of natural nanometric minerals that already behave as nanomaterials for industrial uses. Mineral nanotechnology approaches nanomaterials production by top-down techniques, avoiding synthesis processes and focusing on the materials properties and applications, seeking to comply with the best circular economy and environmental initiatives [5,6].…”

Section: Introductionmentioning

confidence: 99%

Simulation of geological graphene genesis by the piston-cylinder apparatus

et al. 2022

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Stable natural graphene occurs in graphite-and phyllosilicate-bearing low-grade metamorphic rocks. The present work simulates the process of geological formation of graphene using a piston-cylinder apparatus, promoting diffusion between talc and graphite at 700ºC and 900 MPa for a period of 24 h. The experimental products were analyzed by optical and scanning electron microscopy for description of the microstructures formed between the mineral precursors. The talc-graphite diffusion zone was also analyzed by Raman spectroscopy. Results indicate that graphite becomes progressively more deformed near the talc diffusion zone and eventually undergoes cleavage. Graphene becomes stable on the talc substrate in the center of diffusion zone. Therefore, the search for deposits of natural graphene and other nanomaterials in geological context is promising.

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Mineral Nanotechnology in Circular Economy

Cited by 9 publications

References 12 publications

Status quo of graphene geology in Brazil: mineralogical, petrological and materials science contributions

Status quo of graphene geology in Brazil: mineralogical, petrological and materials science contributions

Electrical Resistance Evolution of Graphite and Talc Geological Heterostructures under Progressive Metamorphism

Simulation of geological graphene genesis by the piston-cylinder apparatus

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