Mechanical testing of two-dimensional materials: a brief review

Abstract

Two-dimensional (2D) materials have dominated nanoscience for the last two decades. Among all 2D materials, graphene, MoS 2 , and h-BN are extremely popular and have been tentatively scaled up to fabricate nanocomposites, energy storage devices, flexible electronics, etc., ex situ and in situ mechanical characterization of 2D crystals can help us understand their mechanical behavior and measure their mechanical properties, which are of great significance in both fundamental science and practical engineering. To date, a great effort has been devoted to both theoretical and experimental mechanics with a focus on unveiling mechanical behaviors and quantifying mechanical properties. Beyond original research, several insightful review works have been published with a specific focus on the mechanics of 2D materials. To have a complementary contribution to the overview of the mechanics of 2D materials, we would like to review the developed experimental techniques being used to mechanically characterize 2D materials. The working mechanism and associated advantages and disadvantages of the techniques will be briefly discussed. Based on the existence of arguments in mechanical properties and behaviors of 2D crystals, and immature mechanical characterization of 2D materials, more intensive and comprehensive studies are expected toward a full understanding of these novel and promising materials.

Effect of polyacrylic acid molar mass as a surface modifier on rheological properties of calcium carbonate suspensions

“…The viscosity of the suspension without polymer decreased by increasing shear rate. This is in agreement with (Al-Quraisshi et al, 2020). This may be due to that as the particle concentration increases, the surface modified particles form a network structure and exhibited a negative tensile performance.…”

Bonding, structure, and mechanical stability of 2D materials: the predictive power of the periodic table

“…Measurements of the inherent stiffness and ultimate strength, e.g., by AFM nanoindentation, are available for quasi freely suspended graphene, while the results for most other monolayers such as graphene oxide, h-BN, black P, transition metaldichalcogenides such as MoS 2 and WSe 2 , and MXenes are still preliminary. 16,271,272 Besides the problem of preparing a perfect suspended monolayer uncertainties are due to the interpretation of the experimental data by simple mechanical models. Furthermore, it has been shown that ripples on suspended monolayers may have profound effects on the measured in-plane modulus.…”

“…Unfortunately, reliable measurements of the intrinsic stiffness and ultimate strength, e.g., by indentation, are available only for graphene, while the measurements for other monolayers such as graphene oxide, h-BN, and black P are still preliminary. 16 The monolayer thickness can be defined for free-standing layers, whereas in few-layer assemblies the interlayer spacing changes with the strength of interlayer interaction.…”

“…However, often stronger electrostatic and covalent interaction forces dominate the interaction of a monolayer with the substrate and change the structure. Structural analysis is performed by scanning atomic force microscopy (AFM), 16 scanning tunneling microscopy (STM), in situ microscopy techniques such as scanning electron microscopy (SEM), low energy electron diffraction (LEED), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), selected area electron diffraction (SAED), and high resolution transmission electron microscopy (HRTEM), supplemented by energy dispersive X-ray spectroscopy (EDX). 17 Atomic steps in layered assemblies are used for the direct measurement of the interlayer spacing by AFM and STM.…”

Упругие Свойства Графеноподобных Соединений: Модели Китинга И Харрисона

“…В настоящей работе мы рассмотрим упругие свойства соединений с двумерной гексагональной структурой, т. е. графеноподобные соединения (ГПС), используя оба подхода. Отметим, что, несмотря на более чем десятилетие исследований (в подавляющем большинстве, теоретических), интерес к механическим свойствам двумерных (2D) структур не затухает (см., например, [5][6][7]).…”