Vasić Borislav, Czibula Caterina, Kratzer Markus, R A Neves Bernardo, Matković Aleksandar, Teichert Christian
Institute of Physics Belgrade, University of Belgrade, Pregrevica 118, 11080 Belgrade, Serbia.
Institute of Physics, Montanuniversität Leoben, Franz Josef Strasse 18, A-8700 Leoben, Austria.
Nanotechnology. 2021 Apr 6;32(26). doi: 10.1088/1361-6528/abeffe.
Talc is a van der Waals and naturally abundant mineral with the chemical formula MgSiO(OH). Two-dimensional (2D) talc could be an alternative to hBN as van der Waals dielectric in 2D heterostructures. Furthermore, due to its good mechanical and frictional properties, 2D talc could be integrated into various hybrid microelectromechanical systems, or used as a functional filler in polymers. However, properties of talcas one of the main representatives of the phyllosilicate (sheet silicates) group are almost completely unexplored when ultrathin crystalline films and monolayers are considered. We investigate 2D talc flakes down to single layer thickness and reveal their efficiency for solid lubrication at the nanoscale. We demonstrate by atomic force microscopy based methods and contact angle measurements that several nanometer thick talc flakes have all properties necessary for efficient lubrication: a low adhesion, hydrophobic nature, and a low friction coefficient of 0.10 ± 0.02. Compared to the silicon-dioxide substrate, 2D talc flakes reduce friction by more than a factor of five, adhesion by around 20%, and energy dissipation by around 7%. Considering our findings, together with the natural abundance of talc, we put forward that 2D talc can be a cost-effective solid lubricant in micro- and nano-mechanical devices.
滑石是一种具有范德华力且天然储量丰富的矿物，化学式为MgSiO(OH)。二维（2D）滑石可作为二维异质结构中范德华电介质替代六方氮化硼。此外，由于其良好的机械和摩擦性能，二维滑石可集成到各种混合微机电系统中，或用作聚合物中的功能填料。然而，当考虑超薄结晶膜和单分子层时，作为叶硅酸盐（片状硅酸盐）组主要代表之一的滑石的性能几乎完全未被探索。我们研究了降至单层厚度的二维滑石薄片，并揭示了它们在纳米尺度上的固体润滑效率。我们通过基于原子力显微镜的方法和接触角测量证明，几纳米厚的滑石薄片具有高效润滑所需的所有特性：低粘附性、疏水性和0.10±0.02的低摩擦系数。与二氧化硅基板相比，二维滑石薄片可将摩擦力降低五倍以上，粘附力降低约20%，能量耗散降低约7%。考虑到我们的研究结果，以及滑石的天然储量，我们提出二维滑石可成为微纳机械装置中具有成本效益的固体润滑剂。
