Two-dimensional talc as a van der Waals material for solid lubrication at the nanoscale

Abstract

Talc is a van der Waals and naturally abundant mineral with the chemical formula Mg3Si4O10(OH)2. 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.

MoS2‐decorated talc hybrid for improving the tribological property of Nomex/PTFE fabric composites

“…[25] Talcum (talc) is a kind of common inorganic solid additive with lamellar structure, which has excellent creep resistance property, high thermal stability, and favorable wear resistance. [26] Talc has been widely used to enhance the antiwear property of polymer composite. [27] Katiyar et al have evaluated the friction and wear durability of epoxy-based polymer (SU-8) composite coating filled with talc and graphite.…”

High throughput investigation of an emergent and naturally abundant 2D material: Clinochlore

“…Synthetic materials can be produced in controlled environments, but some processes required for specific material classes are complex and consequently expensive. In an effort to increase the list of naturally occurring LMs that are abundant in nature and could potentially become low-cost sources of 2D materials, recent research has been carried out in the promising group of phyllosilicates minerals, which are wide bandgap insulators that can be mechanically exfoliated down to 1L and FL-flakes [8][9][10][11][12][13][14][15][16], and and can be embedded in van der Waals heterostructures with other LMs [17][18][19][20][21][22][23][24]. The challenge in using naturally occurring van der Waals materials for 2D applications is related to the existence of impurities and defects in their crystal lattice [25].…”

“…Phyllosilicates are a subgroup of silicates that include clays, micas, and chlorites [31]. Most of the investigations of their 2D form have focused on muscovite mica or talc [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23]26,27], and barely explored other minerals of this family, such as chlorites [10]. Within the chlorite group, clinochlore is one of the most abundant mineral.…”

Nanofriction Properties of Mono- and Double-Layer Ti3C2Tx MXenes

“…6−8 Thus, technologically unique 2D materials with superior strength and high thermal stability, such as graphene and transitional metal dichalcogenides (TMD) as well as recently proposed talc, are being used as customizable single-component dry lubricants. 9,10 Additionally, they are widely used as an additive component of solvents and nanofillers composition systems for friction and wear reduction at macroscale. 11,12 Recently, a new class of 2D materials, referred to as MXenes, with over 100 possible and more than 30 experimentally synthesized compositions, gained great attention in tribology research due to their excellent physical and chemical properties, good anticorrosion properties, low friction, and high wear resistance.…”