Typical Analysis

Technical

Technical Fine

Super Fine

Acid Insoluble

0.50%

0.50%

0.50%

Fe

0.25%

0.25%

0.25%

MoO3

0.05%

0.10%

0.15%

H2O

0.10%

0.15%

0.20%

Oil

0.20%

0.40%

0.40%

SiO2

0.20%

0.20%

0.10%

Carbon

0.5%

0.5%

0.5%

Acid Number*

0.5

2.0

3.0

Laser Median Particle Size

< 30 μm

< 6 μm

< 1.5μm

Fisher Number

3 to 4 μm

0.65 to 0.8 μm

0.4 to 0.45 μm

Molybdenum disulfide (MoS2) is the most famous of the single layer transition metal dichalcogenide (TMD) family. MoS2 has been used in bulk for many years as a solid state lubricant, this is due to its low coefficient of friction in addition to its high chemical and thermal stability. All forms of MoS2 have a layered structure, in which a plane of molybdenum atoms is sandwiched by planes of sulfide ions. These three strata form a monolayer of MoS2. Bulk MoS2 consists of stacked monolayers, which are held together by weak van der Waals interactions. Similar to graphite, when MoS2 transitions from a bulk structure to a single layer structure the properties of this material undergo a significant change.

The most striking change that occurs when transitioning from bulk to single layer is the shift in the optoelectronic properties, with the material changing from being an indirect bandgap semiconductor with a bandgap value of approximately 1.3 eV to a direct bandgap semiconductor with a bandgap value of approximately 1.9 eV. Due to the presence of a bandgap in this material there are significantly more uses for MoS2 in comparison to other 2d materials such as graphene.

In recent years, MoS2 has been utilized in flexible electronic applications, promoting more investigation into the elastic properties of this material. Nanoscopic bending tests using AFM cantilever tips were performed on micromechanically exfoliated MoS2 flakes that were deposited on a holey substrate. The yield strength of monolayer flakes was 270 GPa, while the thicker flakes were also stiffer, with a yield strength of 330 GPa. Molecular dynamic simulations found the in-plane yield strength of MoS2 to be 229 GPa, which matches the experimental results within error. Some areas in which MoS2 has already been applied include high on/off ratio field effect transistors due to low leakage currents, memresistors based on layered TMD films, controllable spin and valley polarization, geometric confinement of excitons, tuneable photoluminescence, the electrolysis of water, and photovoltaics/photodetectors.