Epoxy Nanocomposites with Two-Dimensional Transition Metal Dichalcogenide Additives

Abstract

Emerging two-dimensional (2D) materials such as transition metal dichalcogenides offer unique and hitherto unavailable opportunities to tailor the mechanical, thermal, electronic, and optical properties of polymer nanocomposites. In this study, we exfoliated bulk molybdenum disulfide (MoS2) into nanoplatelets, which were then dispersed in epoxy polymers at loading fractions of up to 1% by weight. We characterized the tensile and fracture properties of the composite and show that MoS2 nanoplatelets are highly effective at enhancing the mechanical properties of the epoxy at very low nanofiller loading fractions (below 0.2% by weight). Our results show the potential of 2D sheets of transition metal dichalcogenides as reinforcing additives in polymeric composites. Unlike graphene, transition metal dichalcogenides such as MoS2 are high band gap semiconductors and do not impart significant electrical conductivity to the epoxy matrix. For many applications, it is essential to enhance mechanical properties while also maintaining the electrical insulation properties and the high dielectric constant of the polymer material. In such applications, conductive carbon based fillers such as graphene cannot be utilized. This study demonstrates that 2D transition metal dichalcogenide additives offer an elegant solution to such class of problems.

Understanding the fundamental properties of epoxy molybdenum disulfide nanocomposites

“…The results have indicated that the MoS 2 are in the form of clusters . Osman Eksik et al ., studied MoS 2 dispersability in epoxy resin material using SEM studies and by confocal imaging studies concluding the size of particle at each location is about 420 nm . Similar observations are made in this study indicating the nanofillers are dispersed locally.…”

“…The fundamental properties of the material gets altered by adding nanofillers, namely, silica, alumina, titania etc, to acquire the required electrical, thermal, and mechanical properties . One dimensional nanofillers such as carbon nanotubes and 2D nanofillers like graphene reinforces well with polymer matrices and they are conductive, which limits its usage as insulant in large power apparatus such as electric motors, cables, capacitors and to use as an electric field grading material .…”

“…MoS 2 possesses excellent mechanical properties, such as very high Young's modulus (0.3 TPa) . It is reported that, the incorporation of 0.2 wt% MoS 2 leads to 60% increase in the fracture toughness, 88% improvement of Young's modulus and 53% increase in tensile strength in the MoS 2 /epoxy nanocomposite in comparison to pure epoxy . Dong Wang et al .…”

Photoluminescence from Liquid‐Exfoliated WS2 Monomers in Poly(Vinyl Alcohol) Polymer Composites

“…[11][12][13] However, the broader family of inorganic 2D materials have only recently been targeted for composite applications. For example, both BN and MoS2 have followed graphene as fillers for mechanical reinforcement of polymers, 14,15 while MoS2 has also been used as an additive to reduce wear and improve fire retardency in plastics 16,17 and for photoactuation applications. 18 In addition, both MoS2-and MoSe2-filled composites have been used as saturable absorbers for the production of fiber lasers.…”

“…In the applications described above, [14][15][16][17][18][19][20][21][22][23] the nanosheets were generally first exfoliated in 3 solvents or surfactant solutions and then mixed with polymer solutions. The resultant composite dispersions can then be cast or formed as required.…”