NOVEL METHODS FOR FUNCTIONALIZATION OF WS₂ NANOTUBE

Inorganic nanotubes and fullerene nanoparticles of tungsten disulfide (INTs-WS₂ and IFs-WS₂, respectively) are practically inert, hindering their usefulness in both research and commercial applications. The covalent attachment of functional species onto the surface of INTs-WS₂ is a critical first step in realizing the potential that INTs-WS₂ offer for producing high performance materials, systems, and products. In our previous work, we developed a unique and versatile method for functionalizing carboxylic groups on the nanotubes` surface. In this current research, we have developed a functionalization method via the Vilsmeier-Haack reaction using 2, 2`-bisthiophene-4-carboxaldehyde and POCl₃ as chemically reactive reagents. These coatings should improve the electro-conductivity and mechanical properties of both INTs-WS₂ and IFs-WS₂ inorganic nanomaterials. Using a bithiophene linker allowed us to polymerize any substituted thiophene monomer such as 3,4-ethylenedioxythiophene (EDOT) and 3-thiophene acetic acid (TAA) among others.

Furthermore, we present a new method for functionalization of WS2 nanotubes with a polycarbohydrate-like shell containing free hydroxyl surface groups. The method is based on Lewis acid-activated thioglycosylation chemistry between the nanotubes surface and the carbohydrate unit. We show that shell thickness can be controlled by adjusting the sugar concentration.