Novel Versatile Surface Chemical Engineering of Inorganic Tungsten Disulfide (WS2) Nanotubes & Fullerene-Like Nanoparticles (f-INT-WS2/f-IFs-WS2)

Jean-Paul (Moshe) Lellouche, Department of Chemistry & Institute of Nanotechnology & Advanced Materials, Bar-Ilan University, Ramat Gan, Israel

Transition metal dichalcogenide (TMDC) nanoscale materials, i.e., tungsten disulfide nanotubes and fullerene-like nanoparticles (INTs-WS₂ & IFs-WS₂ respectively) are known to possess quite unique tribological (friction and wear reduction) as well as mechanical hardness/reinforcement properties. However and due to their strong hydrophobicity and chemical inertness, extensive uses regarding their homogeneous incorporation/dispersion into various polymeric matrices have been quite limited. In this context, corresponding surface engineering screening studies lead to the discovery of a novel surface functionalization method that made use of Lewis acid-promoted per-acetylated glucose reaction/rearrangement in the presence of such TMDC inorganic nanomaterials (conformal growth of organic coatings at variable thicknesses). Quite interestingly and following deep spectroscopic/analytical composite characterization that made main/essential use of a pyrolysis/GCMS method for organic coating analysis, it has been found that these functional (polyOH shell) organic conformal adlayers contain hydrophobic 5 and 6-membered aromatic rings (furan & benzene derivatives) that showed strong structural similarity with pyrolysed furfuryl alcohol resins and humin-like compounds (FT-IR analysis). Such structurally well-defined coatings might be also readily derivatized in a 2^nd step of INTs/IFs surface chemical engineering by functional silicates (APTES for example) towards even more hydrophilic composite f-INTs-WS₂ nanotubes, thus opening a quite wide range of novel potential end-user applications (hybrid bioactive hSiO₂ coatings for example, current on-going studies).