Fracture Toughness Characteristics of Stacked Bilayer Graphene via Far-Field Displacement Measurements.

Autor: Arshad MU; Department of Materials Science and Engineering, Texas A&M University, College Station, TX, 77843, USA., Gan Y; Department of Civil, Environmental, and Architectural Engineering, Rolla, MO, 65409-0030, USA., Wei C; Department of Civil, Environmental, and Architectural Engineering, Rolla, MO, 65409-0030, USA., Li J; Department of Civil, Environmental, and Architectural Engineering, Rolla, MO, 65409-0030, USA., Wu C; Department of Civil, Environmental, and Architectural Engineering, Rolla, MO, 65409-0030, USA., Naraghi M; Department of Materials Science and Engineering, Texas A&M University, College Station, TX, 77843, USA.; Department of Aerospace Engineering, Texas A&M University, College Station, TX, 77843, USA.
Jazyk: angličtina
Zdroj: Small (Weinheim an der Bergstrasse, Germany) [Small] 2023 Sep; Vol. 19 (39), pp. e2302499. Date of Electronic Publication: 2023 May 30.
DOI: 10.1002/smll.202302499
Abstrakt: Mechanical properties of graphene, e.g., strength, modulus, and fracture toughness are extremely sensitive to flaws. Here the fracture properties of stacked bilayer graphene sheets (SBLG) are reported, obtained via stacking two individually grown graphene sheets. The SBLG is presented here as a building block for flaw-resilient nanomaterials. The fracture properties of freestanding SBLG sheets, suspended on transmission electron microscope (TEM) grids, are characterized by stretching the TEM grid inside an scanning electron microscope (SEM) chamber and monitoring the local displacements in real-time. The fracture toughness is measured and expressed as a function of the critical displacement required to propagate existing cracks in the experiment via computational models. This approach decouples force and displacements measurements, and utilizes the known elastic modulus along with the known displacement boundary conditions at the onset of crack growth to estimate the far field force and stress. This strategy represents a breakthrough in nanoscale fracture mechanics for statistical analysis and high throughput experimens on multiple samples at a time. Results demonstrate that the SBLG is markedly tougher than as-grown single or multilayer graphene, with a mode I fracture toughness of ≈28.06 ± 7.5 MPa m $\sqrt m $ . The mechanisms leading to a higher toughness of SBLG are also analyzed and discussed.
(© 2023 Wiley-VCH GmbH.)
Databáze: MEDLINE
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