MoS₂/Montmorillonite Nanocomposite: Preparation, Tribological Properties, and Inner Synergistic Lubrication

Abstract

A nano-MoS2/montmorillonite K-10 (K10) composite was prepared and characterized. The composite contains two types of 2H-MoS2 nanoparticles. One is the hollow spherical MoS2 with a size range of 75[Formula: see text]nm, and the other is the spherical nano cluster of MoS2 with a size range of 30[Formula: see text]nm. The two kinds of nano-MoS2 were formed via assembly of numerous MoS2 nano-platelets with a size of [Formula: see text][Formula: see text]nm. A tribological comparison was then made among nano-MoS2/K10, K10, nano-MoS2 and a mechanical mixture of K10 and nano-MoS2. K10 reduced the wear but slightly increased the friction. Nano-MoS2 remarkably reduced both friction and wear. The mechanical mixture demonstrated better wear resistance than nano-MoS2, indicating a synergistic anti-wear effect of nano-MoS2 and K10. The synergistic effect was reinforced using nano-MoS2/K10 instead of the mechanical mixture. A part of the MoS2 in the contact region always lubricated the friction pair, and the rest formed a tribofilm. K10 segregated the friction pair to alleviate the ablation wear but magnified the abrasive wear. S-MoS2 protects K10 and they together function as both a lubricant and an isolating agent to reduce the ablation and abrasive wear.

A review of recent advances in tribology

“…Chemically-modified GO in hydrophobic ionic liquids [132], 4-n-pentyl-4'-cyanobiphyl liquid crystal (5CB) added with graphene [128], graphene sheets anchored with molybdenum disulfide (MoS 2 ) nanoflowers [133], ILs with graphene [134,135], chemicallybonded phosphorus-graphene hybrid [136], alkyl phosphate modified graphene oxide [137], and polyhedral oligomeric silsesquioxane (POSS) grafted graphene oxide [138], were synthesized and used as liquid lubricants or additives. The research on transition metal disulfides (TMDs) liquid additives, especially MoS 2 , mainly focused on the preparation of functional MoS 2 nanosheets [118,139], MoS 2 nanotubes [140,141], hollow fullerene-like MoS 2 [142], Fe 3 O 4 @MoS 2 core-shell nanocomposites [143], and MoS 2 /montmorillonite nanocomposites [144], etc. A new 2D-layered material, black phosphorus (BP), has been used as liquid lubricant additives recently [119].…”

Preparation and tribological performance of MoS2 nanoparticles supported on fly ash microparticles

“…However, the surfaces with nano-MoS 2 and MFA-9 displayed no obvious exfoliated traces, and only furrows were observed. Accordingly, the wear was reduced and the abrasive wear became the main manner (Song et al , 2018; Cheng et al , 2018).…”

“…MoS 2 /FA was prepared using a similar method reported in a previous study on MoS 2 /montmorillonite (Cheng et al , 2018). Nine copies of 0.5 g Na 2 MoO 4 ·2H 2 O and 1.0 g CH 3 CSNH 2 were weighed out and dissolved in 100 mL of deionized water.…”

“…Nano-MoS 2 may be prepared from the precipitation reaction of Na 2 MoO 4 and CH 3 CSNH 2 (Xu et al , 2015). Nano-MoS 2 composites can be obtained via the same reaction on the activated surfaces of montmorillonite and sericite (Cheng et al , 2018; Liu et al , 2017).…”

Inorganic nanomaterial lubricant additives for base fluids, to improve tribological performance: Recent developments

“…Recently, layered-structure materials such as WS 2 and MoS 2 have become popular as lubricant additives in base fluids, owing to their high shear susceptibility. Studies on transition metal disulfide liquid additives (MoS 2 in particular) have primarily focused on the fabrication of functional MoS 2 nanosheets [84,85], MoS 2 nanotubes [86,87], hollow fullerene-like MoS 2 [88], Fe 3 O 4 @MoS 2 core-shell nanocomposites [89], and MoS 2 /montmorillonite nanocomposites [90]. Yi and Zhang [91] fabricated three different types of morphological MoS 2 particles using hydrothermal and solvothermal methods.…”