Functionalization of Tungsten Disulfide Nanotubes with a Conformal Humin-Like Shell

Nanostructures of transition metal dichalcogenides (TMDs) exhibit excellent tribological and mechanical properties. These properties account for the intensive study of their use as additives to polymeric matrices. Functionalization of TMD nanostructures with organic chemical moieties has not yet been widely researched. Functionalization of this nature improves the ability to integrate TMD nanostructures in such matrices. In this paper, a new method for the functionalization of WS₂ inorganic nanotubes (INTs) with a conformal humin-like shell in different thicknesses is presented. The method is based on Lewis acid-activated thioglycosylation chemistry between the nanotube surface and the carbohydrate unit. It is shown that shell thickness can be controlled by adjusting the sugar concentration. A reaction between the functionalized nanotubes and 3-aminopropyl-triethoxysilane (APTES), an amine-terminated silicate, for the addition of different surface functionalities is proposed. This pathway should help improve and expand the range of TMD nanostructure applications.